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ELECTRONICS HI -FI STEREO THEME ISSUE Transistors Take Over Hi -Fi Build Transistor 6-Watt Amplifi The Last Decade in Hi -Fi Plastic Speaker Enclosure

ALSO: Convert FM Tuner to Police Band Stack TV Antennas for DX Sun - Powered Transistor Portable

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olVlake $3 to $5 An Hour in Spare Time You don't have to wait until you get an NRI diploma to start earning. As many others have done, you can be making $3 to $5 an hour in your spare -time as you train, fixing radios and TV sets for friends and neighbors. You learn how to install, maintain and service stereo hi -fi, radios, TV sets (including color), even how to charge for service and how to set up your own spare - time or full -time business. Many students pay for their NRI training out of spare -time earnings long before they graduate.

Skilled Technicians Are in Demand There has never been a time when ambitious men with specialized Electronics knowledge were as much in demand as they are today. From television service shops to launching pads, there's a profitable place for you as a skilled technician to help service, operate, install and supervise Electronically -controlled equipment. The NRI diploma is respected and recognized in business and industry. It can be your key to success in America's "glamor" industry.

Achievement Kit Gets You Started Fast As soon as you enroll with NRI we deliver to your door everything you need to make a fast start in the Electronics training of your choice. This new Achievement Kit is an unparalleled example of the value of NRI home -study training. No other school has anything like it. Find out about the NRI Achieve- ment Kit, about NRI training equipment, about NRI courses, about opportunities for success in Electronics. Send for the NRI catalog. There's no obligation. No salesman will call. NATIONAL RADIO INSTITUTE, Electronics Division, Washington, D. C. 20016.

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TELEVISION -RADIO SERVICING Complete training from basic fundamentals of electricity to home entertainment equipment. You learn to fix radios, hi -fi and stereo sets, black- and -white and color TV, etc. A profitable field full or part time.

2 INDUSTRIAL- MILITARY ELECTRONICS

From basic principles to computers. A compre- '

hensive training plan that teaches you the fundamentals, then takes you into such modern -day miracles as servos, telemetry, multiplexing, pulse circuitry, data processing, other important subjects.

3 COMPLETE COMMUNICATIONS*

Designed to teach and provide you with actual practice in operation, service and maintenance of AM, FM and TV broadcasting stations. Also covers marine, aviation, mobile radio, facsimile, microwave, radar.

4 FCC LICENSE*

Specifically designed short course to prepare you for your First Class FCC Radiotelephone License examinations. You begin with a thor- ough background in fundamental Electronic principles, advance to required subjects covering equipment and procedures.

5 MATH FOR ELECTRONICS

A brief course for engineers and technicians who need a quick review of the essential mathe- matics used in industry, communications, in government jobs. Basic arithmetic review, shortcut formulas, modern digital number system, much, much more.

BASIC ELECTRONICS A concise course to teach modern Electronics terminology and components. A wealth of practical, useful information to help you better understand the field, to give you some technical knowledge. For anyone who wants basic understanding of Radio-TV Electronics.

ELECTRONICS FOR AUTOMATION This course is not for beginners. Offered for men with some fundamental knowledge of Elec- tronics who want better understanding of Auto- mation in present day use. Covers process control, ultrasonics, telemetering, and remote control, electromechanical measurements, other subjects.

AVIATION COMMUNICATIONS* This course prepares you to install, maintain, service aircraft communications equipment. Covers direction finders, ranges, markers, Loran, Shoran, Radar, lánding systems. Earn your First Class FCC License with Radar Endorsement.

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MOBILE COMMUNICATIONS* Learn to install and maintain mobile equipment and associated base stations. Covers transmitters and receivers used by police and fire departments, public utilities, construction projects, taxis, etc. Prepares you for a First Class FCC License.

*NOTE: You must pass your FCC License exam (any Communications course) or NRI refunds in full the tuition you have paid.

The Oldest and Largest

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At NRI you are backed by 50 Years of

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Fifty years ago, a school teacher named James E. Smith started giving extra instruction to four of his students in the "mysterious" new field of radio. From that small beginning, National Radio Institute has grown to be America's largest home -study school in the many fields of Electronics. Nearly three- quarters of a million students have enrolled over the years. This vast experience is behind NRI's

meaningful, interesting, easy -to- understand methods of training; methods that make Electronics a practical subject for almost anyone to learn no matter how much r how little formal education he has. But experience is only the base upon which NRI is

hilt. Today there is a staff of more than 150 dedicated keople working with you as a "class" of one, keeping training material up- to- the -minute, providing consultation services as you train, advising you about new developments in Electronics, even helping you with job placement when you're ready. Ask men whose judgment you respect about NRI training. And send for the catalog we offer. Read about opportunities in Electronics, about new developments, about NRI itself and the variety of training plans open to you at reasonable cost. Mail the postage -free card today.

JOIN MEN LIKE THESE - TRAIN FOR SUCCESS WITH NRI

"I went into my own business six months after finishing the NRI Radio - TV Servicing Course. It makes my family of six a good living. We repair any TV or Radio. I would not take anything for my training with NRI. It is the finest."

DON HOUSE, Lubbock, Texas

"Many thanks to NRI for the Elec- tronics training I received. I hold a first class FCC License and am employed as a studio and master control engineer /technician with KXJB -TV."

RONALD L. WOOD, Fargo, N.D.

"I am a Senior Engineering Aide at Litton Systcms, in charge of checkout of magnetic recording devices for our computers. Without the help of NRI 1 would probably still be working in a factory at a lower standard of living."

DAVID F. CONRAD, Reseda, Calif.

"NRI training enabled me to land a very good job as Electronic Technician with the Post Office Dept. I also have a very profitable spare -time business fixing Radios and TV."

NORMAN RALSTON, Cincinnati, Ohio

VOLUME 23 NOVEMBER, 1965 NUMBER 5

'_ t POPULAR ELECTRONICS is Indexed

in the Readers' Guide to Periodical Literature

This months cover photo by Bruce Pendleton

Special Hi -Fi /Stereo and Audio Features 1956 -1965: Hi -Fi Ten Years Later Lawrence LeKashman 41

Hi -Fi Stereo for '66 -In Solid Hans Fantel 47 Unique 99¢ Speaker Enclosure John N. Ayres 52

Solid -State 6 -Watt Amplifier for 10 Bucks Charles E. Fenoglio 78

Electronic Construction Projects Super -Sens Louis E. Garner, Jr. 57 Protect Your Car's Electrical System Charles Erwin Cohn 66 Don't Junk Your Old FM Tuner Charles E. Francis, KBVRX 83

Let the Sun Power Your Portable Homer L. Davidson 85

Tonal Darkroom Timer or Metronome Frederick W. Chesson 95

Communications Satellites on the Air 38 Predicted Radio Receiving Conditions Stanley Leinwoll 72

Short -Wave Listening: Safety Rules for SWL's Hank Bennett, W2PNA 87

DX Canada Awards 88 English- Language Newscasts to North America Robert Legge 89 On the Citizens Band: Project Interview on TV Matt P. Spinello, KHC2060 90 Ham Hobby Clearinghouse 92 Amateur Radio: Useful Tips on Contest Operating _ ._. Herb S. Brier, W9EGQ 93 Short-Wave Monitor Certificate Application 127 DX States Awards Presented 128

Electronic Features and New Developments Zero -Beating the News 54 The Ham Walt Miller 56 How to Stack TV Antennas to Increase Signal Strength and to Reduce Ghosts

Lon Cantor 63

Electronic Math Quiz Robert P. Balin 67

Parts Profiles Don Lancaster 76

Solid State Lou Garner 78

ALPHA -COM Ed Bukstein 81

Get That Beam Antenna Shot 82

Departments Letters from Our Readers 6

Reader Service Page 15

New Products 22

Tips & Techniques 27

Electronics Library 30

Operation Assist 100

Copyright © 1965 by ZIFF -DAVIS PUBLISHING COMPANY. All rights reserved.

POPULAR ELECTRONICS is published monthly by Ziff -Davis Publishing Company at 307 North Michigan Avenue, Chicago, Illinois 60601. November. 1565, Volume 23. Number 5. ) Ziff -Davis also publishes Skiing. Flying, Busi- ness /Commercial Aviation, Popular Boating, Car and Driver. Popular Photography, HiFi- Stereo Review, Electronics World, Modern Bride. and Skiing Trade News.) One year subscription rate for U.S.. U.S. Possessions and Canada. S4.00; all other Foreign. $5.00. iSchedule for payment in foreign currencies may be found elsewhere in this issue.) Second Class postage paid at Chicago. Illinois. and at additional mailing offices. Authorized as second class mail by the Post Office Department. Ottawa, Canada. and for payment of postage In cash.

Something new! \ LEARN AUTOMOTIVE and Maintenance ELECTRICITY AT HOME! Here's another great opportunity for the man

who wants his own business or a bigger pay check with a brighter future. It is a NEW DeVry program that gives you the advantage of earning while you learn.

Prepare in spare time at home for profitable jobs which can take you all the way from troubleshooting on the electrical systems of automobiles, marine engines, trucks, tractors and other gasoline engines, to the general maintenance of electrical equipment in the home or in light industry.

DeVry's new program "brings the classroom to your home" through the magic of AUDIO- VISUAL AIDS: Lectures recorded by DeVry in. structors combined with colorful 8 x 10" transparencies to make learning easier. You get the advantages of "programmed" learning through modern texts which are also handy for future

reference. To develop practical skill, you get and keep valuable shop equipment and manuals. This includes building the brand new DeVry Transistorized Automotive Analyzer and the DeVry Silicon Battery Charger - ideal "tools" for earning extra money as you go.

This new program covers the entire electrical systems in automobiles and other vehicles, including transistorized ignition systems, alterna- tors and regulators, and other applications. In the maintenance field, it covers lighting, electric motors, controls, wiring - even transistors. The graduate from this program can he either a

specialist as a troubleshooter on the electrical system of an automobile, or handle electrical lighting, heating, alarm and control systems. It is ideal for "one man" maintenance departments.

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ECTRONICS Across the continent, leading employers of personnel trained in elec tronics tell us that DeVry training is "Tops." Get the full story o?

DeVry Tech and the advantages it offers, by filling in the coupor below. The two free booklets pictured below tell of many fine oppor tunities for trained men in electronics: the great variety of jobs. from research, production, operation, maintenance and servicing of electronic equipment - to a neighborhood TV -radio sales and service business of your own. They'll tell you too, how DeVry has prepared men for good jobs with outstanding firms: on practical, "brass- tacks" problems with actual electronic equipment. Here's good news: you don't need advanced education or previous technical experience to get started. If you can follow simple directions, you should be able to prepare with DeVry's help for real money in a

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4

POPULAR ELECTRONICS WORLD'S LARGEST- SELLING ELECTRONICS MAGAZINE

PHILLIP T. HEFFERNAN PUBLISHER

OLIVER P. FERRELL EDITOR

ROBERT CORNELL, WA2HDQ MANAGING EDITOR

JOHN D. DRUMMOND TECHNICAL EDITOR

WILLIAM GALBREATH ART EDITOR

MARGARET MAGNA ASSOCIATE EDITOR

CHRISTOPHER SHERIDAN ASSOCIATE EDITOR

ANDRE DUZANT TECHNICAL ILLUSTRATOR

NINA CHIRKO EDITORIAL ASSISTANT

PATTI MORGAN EDITORIAL ASSISTANT

H. S. BRIER, W9EGQ AMATEUR RADIO EDITOR

M. P. SPINELLO, KHC2060 CB EDITOR

L. E. GARNER, JR. SEMICONDUCTOR EDITOR

H. BENNETT, W2PNA SHORT -WAVE EDITOR STANLEY LEINWOLL

RADIO PROPAGATION EDITOR

LAWRENCE SPORN ADVERTISING SALES MANAGER

ARDYS C. MORAN ADVERTISING SERVICE MANAGER

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One Park Avenue, New York, New York 10016

William B. Ziff, Chairman of the Board (1946 -19531 William Ziff, President

W. Bradford Briggs, Executive Vice President Hershel B. Sarbin, Vice President and General Manager

Philip Sine, Financial Vice President Walter S. Mills, Jr., Vice President, Circulation

Stanley R. Greenfield, Vice President, Marketing Phillip T. Heffernan, Vice President

Frank Pomerantz, Vice President, Creative Services Arthur W. Butzow, Vice President, Production

New York Office (212 ORegon 9 -7200) One Park Avenue, New York, New York 10016

Eastern Advertising Manager, RICHARD J. HALPERN

Midwestern Office (312- 726 -0892) 307 North Michigan Avenue, Chicago, Illinois 60601 Midwestern Advertising Manager, JAMES WEAKLEY

Western Office (213 CRestview 4 -0265) 9025 Wilshire Boulevard, Beverly Hills, California 90211

Western Advertising Manager, BUD DEAN

Circulation Office Portland Place Boulder, Colorado 80311

POPULAR ELECTRONICS

ir

After we put our new line of walkie- talkies together, we take them apart. TC h ),a. cur talkies.' You he': we are.

Maybe 99 out of 100 are ready to leave the Fanon plant in perfect condition, but we know there's always the chance of t fluke slipping through. That's why we don't believe in "quickie" shipments to your electronics dealer, We prefer to take an extra look into Things first. So we take every single Citizen's Band transceiver apart and give it a rigor- ous go=ng -oven instrument resting, air testing. the works. Want to do a little investigating of your own? We'll gladly pruside the screwdriver.

Star1 at the top of our line. The Fanon "Commander offers -_,r -watt power from 13 powerful transistors. with our exclusive 'Free-call" standby circuit to save battery power when the unit isn't in use. Next in line is the 11- transistor "Pathfinder ", with 240 millíwatt power, in a rugged, die -cast loosing. Or you may want to take a took at our r a, i t

transistor model, the 100-re, output "Outride- owe built-in squelch circuit,. There's also our nee model, ruggedly built to take autdoor abuse, with a 100mw

November, 1965

9transistor circuit; a .d the "Iran -Bieter of transistor be,hselter for the past three years ti the e, or- omy price reege are ttre "Sanger', a 5- transistor superhet with an excebent signet -te -noise rat c, 3sul et 3- transistor -Explorer the perfect felkke for to - '

For outdoor sparts. construe; , , -

use, there's a Fan an CB wa k., - - and your budget. tau. They're pr -,

isn't comforting to know that walkie- talkie ycj can re -y on a ,.

extra pains toiisure quality? We-think sc. But don't tape our novel for 4. See For yourself, The The next tame you drop by your eectronics dealer, bring

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that performs on cue! Today's lighter tracking forces and more delicate stylus assemblies have increased the danger of record damage Iront manual handling. To eliminate this hagard, the Garrard Lab 81) now incorporates an ingenious tone arm cueing control. It works in three ways:

(I) To play a single record: Press the Manual tab. This starts the motor and activates the tone arm cueing control. The arm stays suspended a safe hall inch over the record. Position the tone arm over the first for any ) groove. No,. press the cueing control and the stylus lowers gently into the groove.

This cueing feature also enables you I'_1 to cue a record or (3) to pause during manual or automatic plan.

The Lab 80 is $99:50. less base and cartridge. The same great Garrard plant that builds the Lab 80 also builds three other fine automatic turntables. There is a Garrard for every stereo system.

For your complimentary copy of the new 32 -page Comparator Guide, use the coupon below.

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LETTERS FROM OUR READERS Address correspondence for this department to:

Letters' Editor, POPULAR ELECTRONICS One Park Avenue. New York, N. Y. 10016

IN THE BEGINNING THERE WAS AN "AM"

Mr. Loniak's explanation "Letter" ( June, 1965 )

of the origin of the term "ham" was very inter - esting and is certainly more credible than many other explanations that I have read. However, I believe radio amateurs have always been called "amateurs," and since there is a tendency in our language to shorten often -used words of more than one syllable, it seems reasonable to assume that the term "amateur" might have been short- ened to simply "am." For a short time, amateurs might have been calling themselves radio "ams." Then, somewhere along the line, the word "am" could have picked up the aspirate "h," resulting in the familiar term "ham.''

DAVID G. LEEPER, K1YS7 Longmeadow, Mass.

REMEMBER WHAT THE SPIDER DID

"Plan Now For Your License" ( July, 1965 )

has encouraged me to try again. I have studied many times for my ham radio license, but have been easily discouraged. If I don't get it now, I

never will. RICHARD BALI. Bronx, N. Y.

Richard, it's 'north another try.

GRANDMA'S BREADBOARD UPDATED -UPDATED

Having been instrumental in the development of the DeVry modular breadboarding components. I quite naturally read the September, 1965 issue with much interest. Judging from our recent mail, however, the article which accompanied the cover picture ("Grandma's Breadboard Updated," p. 6 7) caused some confusion in the minds of some of your readers. The confusion apparently stems from the fact that we have developed two breadboard systems.

The modular system illustrated on the Septem- ber cover is the newer and more flexible system. The components pictured can be purchased either separately or as a kit. The most popular kit in- eludes a good quantity of white Celcon connectors, red Cvcolac panels and nylon stacking rods in a plastic case for $18.50 complete. Individual components can be purchased for as little as 30 cents each.

The original system developed by DeVry does list for .37.30 as indicated in the article, but is completely different in appearance. It is marketed by DeVry Industries Inc. (formerly Paromel Electronics), and features a large "see through" base of clear plastic. The original system is used

6 POPULAR ELECTRONICS

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Other IRectronic products: Garage Door Opener, Guitar Amplifier, Wireless Intercom, Electronic Metronome, Telegraph Code Sender, Remote Control Devices. This is a new, space -age adventure in pre- fabricated electronics. Simple, multi -purpose blocks (IRect- o- paks *) enable anyone to build 20 different electronic products for home and outdoor use. No mechanical or electronic skills needed. It's easy. It's fun. For outdoor use, instant, battery- operated IRectronic Portables: Walkie- Talkie, Electronic Megaphone, Boat Horn, Guitar Amplifier, P.A. System, Remote Photo Flash Slave, and Danger Blinker. All powered by a single 6 volt battery.

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November, 1965 7

Thinking of college and a space age career in

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LETTERS (Continued from page 6)

extensively by schools where wiring templates are positioned underneath the board to guide students in circuit construction.

MALCOLM HOUGHTON Director of Education DeVry Technical Institute Chicago, Ill.

MORE ON "HAMS WITH OTHER HOBBIES"

I was glad to see that POPULAR ELECTRONICS has agreed to serve as a clearinghouse for hams with other hobbies. Fm now anxiously awaiting the results -with optimism. However, there are bound to be some problems in getting people together at any one given time, on a given band, and with a specific hobby interest. Perhaps experimental pathfinder type groups would help to overcome these problems. The experience of these experimental groups could then be written up for the guidance of others. I would like to set up one such group, within the limits of my rig and antenna system, and perhaps other hams who feel as I do, will set one up also.

ART TAYLOR, WOEVC Lincoln, Nebr.

Go to it, Art; and we offer the same encourage - ment to any other ham who would like to set up a net. See page 92 for the first edition of the "Ham Hobby Clearinghouse."

COLOR ORGAN BREAKS SOUND BARRIER

I have just built the "Color Organ" (March. 1965) but I cannot get it to work without a lot of volume. I am driving a pair of University

\ l I

// -------"7j. /2121

Op/

"Senior II" speakers with a 70 -watt Allied transistor amplifier. Can you recommend a bulb that would light up at normal volume levels?

JOHN F. GIBSON Barstow, Calif.

I built a color organ. Could you please tell me how I can turn down the volume and still have the colored lights.

SERI KITT Los Angeles, Calif.

John and Seri, just insert an L -pad between the speakers and the amplifier to quiet down the speakers to a comfortable listening level. Connect the color organ directly to the amplifier. The #47 bulbs have tested out quite well. Smaller bulbs are susceptible to quicker burnout and do not emit enough light to properly illuminate the photocell. Another solution is to add a separate amplifier between the color organ and your reg - ular amplifier or preamp. The only justification


Use this check list before you install a home TV distribution system

COAXIAL VHF TWINLEAD* VHF

COAXIAL UHF /VHF

TWINLEAD* UHF /VHF AND UHF ONLY

Channels received 2 -13 2 -13 2 -83 2.83 (14 -83 for UHF only)

Color reception when properly installed Excellent Excellent Excellent Excellent Cable loss: @ channel 13 for VHF only @ channel 83 for UHF /VHF

4 db (foam filled) 6 db (solid)

1.8 db /100 ft. @ Channel 13

9 db (foam filled) 13 db (solid)

5.6 db /100 ft. @ Channel 83

Loss increase when wet Nil Negligible Nil Negligible Reception when run near or through small metal areas Excellent Excellent when

properly installed Excellent Excellent when

properly installed Reception when run near or through considerable amounts of metal /

Excellent Not recommended

Excellent Not recommended

Ease of installation More difficult Easy More difficult Easy

Extra parts required Connectors, matching transformers

None Connectors, matching transformers

None

Performance in strong -signal areas Excellent Excellent -fair ** Excellent Excellent- fair ** Performance in weak -signal areas Excellent Excellent Excellent Excellent Cable pickup of interference (ignition, appliances, etc.) None * ** None -slight ** None * ** None -slight **

"A high quality, low -loss foam encapsulated cable type "Depends upon local conditions "'Poorly designed accessories will pickup interference.

Once you know the facts -there is one best choice for your home system- Blonder- Tongue. Whether you prefer 300 ohm or a 75 ohm coax system, Blonder- Tongue has the products you'll need. There is only one way you can protect your home TV system against obsolescence when new UHF stations come on the air - that's with a Blonder- Tongue all- channel UHF /VHF system. Blonder- Tongue products designed for all- channel home systems include: All- channel signal amplifiers (V /U -AII -2 indoor and U /Vamp -2 mast mounted); all- channel couplers (A- 102 -U /V two -set and A -104- UV four -set). Rounding out the all- channel concept are UHF /VHF matching transformers (Cablematch U/V set mounted; MT -283 mast- mounted) and the TF- 331 -U /V flush- mounted feed -thru. Take your pick. Blonder- Tongue makes them all -and all are "Color Approved ". Buy the line with 15 years of quality leadership. Write for free booklet "How to Plan a Color- Approved Home TV System ".

BLONDER-TONGUE 9 Alling Street, Newark, New Jersey 07102 home TV accessories closed circuit TV community TV UHF converters master TV

CIRCLE NO. 7 ON READER SERVICE PAGE November, 1965 9

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Name

Address _._..._...._

City Zone State I- J

CIRCLE NO. 30 ON READER SERVICE PAGE 10


for the low gain is the low price . . . normally a color organ sells for about five tintes more money.

"SIDEARMS" FOR CAMPER'S SPECIAL WANTED

Congratulations on the "Camper's Special'. (August, 1965). I have been looking for a rig like this for some time. There's only one problem-I need an inexpensive battery -operated receiver to match.

BOB Moc2YOLOwSS1, WB2PWA Linden, N. J.

I have completed two Camper's Specials and would like to modulate them with a suitable transistor modulator.

E. J. ANTOINE, VE5EA Davidson, Sask., Canada

The Camper's Special calls for three B&W Miniductors and two 2N3053 transistors. I have not been able to get these parts.

DAYTON JONES, WN3DVH Philadelphia, Pa.

The drawing of the antenna shows the lead -in connected to TSI. Shouldn't it be connected to T.12?

WAYNE J. SHOPE, K4ANL Charlotte, N. C.

Looks like a busy day for the Camper's Special, but here goes. Wayne, don't shoot. We give up.

The antenna is supposed to be connected to TS'. The text is correct. D.J., if your local electronics parts distributors can't help you on these parts, try a mail -order house. Lafayette',s 1966 catalog lists the transistors for 09 cents each and the coils for 62 and 68 cents each. E.J., you might cou- culer the 6 -watt transistor amplifier on page 73 of this issue. Bob, we saved you for last because we are .still working on a Camper's Special transceiver.

POPULAR ELECTRONICS IS FOR HOBBYISTS

In one reader's opinion, you have successfully filled the gap between a technical trade publication and a layman's type of journal. The descriptions of how your circuits work have saved me more than once when it came time to trouble- shoot a project.

The following information may be useful to you in statistical compilations. I am 26 years old, have a degree in Economics and hold a position as a Systems Analyst ( Data Processing Busi-

POPULAR ELECTRONICS

i r

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The famous RCA 5 -inch scope

NOW WITH MOPE FFATURES

TO SIMPLIFY YOUR JOB

Here's the latest model of the famous RCA 5 -inch scope: the NEW WO -91B

Provision for connecting signals directly to the vertical deflection plates of the CRT. Permits observation of high frequency RF waveforms, such as trapezoidal and wave -envelope modulation patterns.

Two -stage sync separator simplifies checking of TV horizontal and vertical sweep synchroniza- tion... provides exceptionally solid lock -in action on composite TV signals.

Choice of wide -band or high -sensitivity, narrow - band display.

Complete with RCA WG -300B Direct /Low Cap. Probe and Cable.

Optional at slight extra cost: RCA WG -354A slip - on capacitance -type voltage- divider probe that extends the range of the scope to permit observation of signal pulse amplitudes up to 5000 volts. RCA WG -302A slip -on RF /IF /VF signal tracing probe for RF applications from 100 Kc to 250 Mc.

WO -91B Scope: $249.50 WG -354A Probe: $ 7.50* WG -302A Probe: $ 8.20*

Ask to see it at your Authorized RCA Test Equipment Distributor.

Optional distributor resale price. All prices subject to change without notice. Prices may be slightly higher in Alaska, Hawaii and the West.

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011011 The Most Trusted Name in Electronics



ness Systems). I have been reading your magazine since 1958, and I have built about 15 kits (hi -fi. test equipment, tach, and sonar). My wife also builds kits -an FM tuner among others. My other hobbies are photography, guns, and model railroading.

DAVE MCBURNEY Yorba Linda, Calif.

Our computer tells us that you were about 18 years of age when you started to read PE, and that it's good to have such loyal readers. Thank you for the statistics, Dave, but don't be surprised to hear that many others dwell in the sanie "stati,tiral" house.

TEMPUS FUGIT, BUT - In the "Current Stations Reports,' (August,

19650, you said that Radio Luxembourg 1 on 233 kc. was heard in New England as early as 1820 with rock -and -roll music. Is this true? I always thought that wireless radio transmissions weren't possible until 1016 and the first radio wasn't on the air until 1921.

ROBERT WivACc Elizabeth, Pa.

Even Dr. Mahlon Loomis, the real inventor of wireless, didn't create a spark until 1894 (October issue, 1965). We raised our eyebrows about

233 kc., Robert, not 1820. Our Short- ll'ave Editor did say the beacon that normally operates on this frequency was not on the air. So far as "1820" is concerned, it stands for 6:20 P.M., Eastern Standard time, as all SWL's know. lire guess you'rr not a short -wave listener yet.

OSL BUREAU, LONDON

We have read with interest the letter from S. J. Stansfield, WASGDR, entitled ` QSL's From Iron Curtain Not Propaganda" (August. 1965) re- ferring to QSL Bureau services maintained by the International Short Wave League. We would like to point out that our headquarters address is 12 Gladwell Rd., London, N.8 -not 86 Barrenger Rd., as stated in Mr. Stansfield's letter. The use of the QSL Bureau is free to members, and the Bureau handles both amateur and broadcast QSL's and reports. Membership details are available upon request.

PETER BvsH, Hon. Sectv./Treas. International Short Wave League London, England

"WATCH OUT" FOR THE LIGHT WATCHMAN

In your article on the "Li'1 Dusker -the Light Watchman" (September, 1965) you have a Sigma 5HC2 photocell, Allied stock number 9 E 307, in the Parts List. We have not been supplying this photocell since last November because it was dropped by the manufacturer. However, we can

(Continued on page 20)

Top sensitivity, even in the arctic... One microvolt sensitivity, even at -10° F. 0.4 microvolt sensitivity + 10° F. through + 125° F.... signal pulling capability that you can depend on, even in the arctic.

Completely solid state, the Amphenol "Six Hundred" has replaced the relay with high speed electronic switching to make it far more rugged than comparable equipment. Its dual conversion superhetrodyne receiver, with 4 stages of amplification provides outstanding selectivity.

Other significant advantages include a

powerful 31/2 watt output, current drain that is actually less than a flashlight, and 10 crystal controlled channels.

The 600 is a 12 VDC compact, mobile unit at $169.95; its companion model, the 625, in the same compact cabinet, includes a universal 120 VAC -12 VDC power supply at only $ 20 additional. For more informaton including complete specifications, contact your local Amphenol communications distributor or write direct. DISTRIBUTOR DIVISION

`Imnheno, Amphenol Corporation e 2875 S. 25th Ave., Broadview, III. 60155

CIRCLE NO. 4.0N READER SERVICE PAGE 12 POPULAR ELECTRONICS

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Only the LPV combines frequency -independent design with capacitor -coupled electronic dipoles for ... Higher, more uniform gain and narrower directivity on channels 2 to 83 -and FM.

SEE YOUR JFD LPV DEALER TODAY!

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world's largest manufacturer of TV & FM antennas


November, 1965 13

. Perfection results from CHOICE ...NOT CHANCE

MUSICAL BEST -BUY

MODEL M7 /N2I D

Top -rated cartridge featuring the highly compliant N21D tubular stylus. Because of unusually clean mid -range (where most music really "happens ") it is especially recommended if your present system sounds "muddy." For 2 -gram optimum tracking (not to be used over 21/2 grams). Only $17.95 (Also, if you own an M3D or M7D, you can upgrade it for higher compliance, (if tracking force does not exceed 21/2 grams, with the N21D stylus for only $12.50.1

THE "FLOATING" CARTRIDGE

M80 E

GARD- A- MATIC® WITH ELLIPTICAL STYLUS

Bounce -proof, scratch -proof performance for Garrard Lab 80 and Model A70 Series automatic turntables. Especially useful for applications where floor vibration is a

problem. Spring -mounted in tone arm shell. Unique safety feature retracts stylus and cartridge when force exceeds 11/2 grams . . . prevents scratching record and dam- aging stylus. $38.00

14

ALL THE MOST WANTED FEATURES

M55E 15' TRACKING,

ELLIPTICAL STYLUS

Professional performance at a

modest price. Compares favorably to the incomparable Shure V -15. except that it is produced under standard Shure quality control and manufacturing techniques. Re- markable freedom from IM, Har- monic and tracing distortion. Will definitely and audibly improve the sound of monaural as well as

stereo records. A special value at $35.50. Upgrade M44 cartridge (if you can track at 11/2 grams or less) with N55E stylus, $20.00

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For the purist who wants the very best, regardless of price. Reduces tracing (pinch effect), IM and Har- monic distortion to unprecedented lows. 15° tracking. Scratch -proof, too. Produced under famed Shure Master Quality Control Program

literally hand -made and individually tested. In a class by itself for mono as well as stereo discs. For manual or automatic turntables tracking at 3/4 to 11/2 grams. $62.50

High Fidelity Phono Cartridges . World Standard Wherever Sound Quality is Paramount Shure Brothers, Inc., 222 Hartrey Ave., Evanston, Illinois


POPULAR ELECTRONICS

POPULAR ELECTRONICS PkODUCT SEI NICE PAGE

You can get additional information promptly

concerning products advertised or mentioned

editorially in this issue

1 Circle the number on the coupon below which corresponds

to the key number at the bottom of the adver- tisement or is incorporated in the editorial mention that interests you.

2 Mail the coupon to the address indicated below.

3 Please use this address only for Product Service requests.

POPULAR ELECTRONICS P. O. BOX 8391

PHILADELPHIA, PA. 19101

Please send me additional information about the products whose code numbers 1 have circled

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76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100

NAME ,Print clearly)

ADDRESS

CITY STATE ZIP CODE

VOID AFTER DECEMBER 31, 1965 11

November, 1965 15

(-

"Get more education

or get out of electronics

...that's my advice."


November, 1965

Ask any man who really knows the electronics industry. Opportunities are few for men without advanced technical education. If you stay on that level, you'll never make much

money. And you'll be among the first to go in a layoff.

But, if you supplement your experience with more education in electronics, you can become a specialist. You'll enjoy good income and excellent security. You won't have to worry about automation or advances in technology putting you out of a job.

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LETTERS ( Continued from page 12)

supply a somewhat superior photocell to work in this circuit: Special Clairex 5M5, for $2.00. The Clairex unit would have to be obtained on special order, but if there is a substantial demand for it we will stock it.

J. W. RLTBIN Allied Radio Corp. Chicago, Ill.

1V/rile we are on the subject, here's some data on relay KI in the "Li'1 Dusker." It's made hs' Philips -Advance, part number 15- 24 -1C. The coil is rated at 24 volts, 1100 ohms. Contacts are 1

amp. Price, 51.50.

DARLINGTON PAIR NOT LOVEBIRDS

Not long ago I ran across a reference to a "Darlington pair" in connection with an article

on transistors, but there was no explanation. Can ou tell me what they are?

E.A. HEATH Palo Alto, Calif.

Sure thing, E.A. See the How It Works section of "Super Sens " on page 57 of titis issue.

REAL POWER WANTED, NOT STEAM POWER

I enjoyed the "Steam- Powered Ham Rig" (July, 1965). Now, how about using real power, but still in t he milliwatts?

MIKE MARTZ Sidney, Ohio

The Stanley Steamer must have been before your time, Mike, or sou would have more regard for the power of steam. If you wish, you can try a ,z-volt battery hookup instead of the steam engine.

DOES IT PAY TO BUY CB EQUIPMENT?

I would like to know if it is wise to buy a CB set at this time, in view of all the new rules and regulations to knock out the CB'er.

CHARLES GROTTICET.r.r, JR. Brooklyn, N. Y.

Charles, a great number of CB'ers share our view that the FCC regulations are designed to provide maximum practical use of the airways. We don't think the FCC wants to knock out the CB'er. Whether or not it pays for you to buy a

CB set depends upon what you intend to do with it. ---

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Send me complete MASTER LAB loll 9 kits) in one shipment I enclose $37.55 Full Payment, Postage Paid. Send me only the Unit. I enclose $ , Full Payment, Postage Paid.

Name

Address

City & State CZIP COLE

AMERICAN BASIC SCIENCE CLUB, INC. 501 East Crockett St . San Antonio. Texas 78202

A MASTER LAB CHRISTMAS - FOR A HAPPY NEW YEAR !

NEW

PRODUCTS

Additional information on products covered in this suction is available from the manufactur rs. Each ir product is identified by a rode nuniinr. To obtain further details on any of them, simply fill in and niail thy coupon on page 15.

"KWIK -START" IGNITION SYSTEM

When points or "condensers" fail, your car's engine will still run with a "Kwik- Start" emergency ignition system. You won't have to push your car or have it towed to the garage -you can drive there. Produced by Ktoik- Start Enterprises, the system is easy to install -you just disconnect the primary wire between distributor and coil and attach the Kwik -Start unit. In addition, if the points or "condensers" are okay, Kwik -Start will tell you so and try to diagnose the trouble. It's available in both 6- and 12 -volt models.

Circle No. 75 on Reader Service Page 15

SUPERHET CB WALKIE- TALKIE

The Model HA -130 introduced by Lafayette Radio Electronics is a low -cost superheterodyne walkie- talkie for the Citizens Band. Housed in a durable black - and- silver simulated leatherette plastic case, its flve- transistor, two -diode circuit employs a crystal- controlled receiver and a 100 -mw. transmitter section. each using plug -in, easy -to- change crystals. Simple to operate, the HA -130 has only a push -to- talk switch and an on /off volume control. The collapsi- ble 34" antenna radiates power effectively for up to one mile. Channel 10 transmit and receive crystals, an earphone jack, and a 9 -volt battery are supplied with the unit.


MAGNET VARIETY KIT

Ever consider using a magnet as a tool or knife holder? As a dashboard retainer fitting for your car? As a holder for pipe or flashlight brackets? If you'd like to put magnets to practical use around your home, office, or recreation area, you'll be interested in the low -cost variety kit available from Edmund Scientific Company. It contains 16 magnets, in nine different shapes, and of several com-

22

positions -including a rubber strip and flexible material containing thousands of tiny individual magnets.


POCKET WIRING TOOL

Cutting juniper wit es and component leads to measured length, stripping insulation, and tailoring lead bends are the main functions of the new Jades "Snip -N- Strip" tool. Con-

structed of light-

weight, glass - filled Nylon plastic, it contains a retract- able surgical - steel knife blade and comes with a

convenient, removable pocket clip. A trigger - actuated set of quadrilateral shear blades cleanly cut conductors without distorting stranded types, and a sliding scale on the side of the tool provides an accurate, quickly adjustable length gauge.


UNI- SUSPENSION TURNTABLE

New from Thorcns is the TD -150 AB two - speed (33',3 and 45 rpm) turntable. The tone arm board and turntable platter are on a single adjustable spring- loaded suspension. Balanced in horizontal and vertical planes, the tone arm incorporates a low -mass plug - in cartridge shell with an exclusive patented system for adjusting vertical tracking angle. The motor is a 375 -rpm double -synchronous type. Rum- ble, wow, and flutter are said to be below NAB stereo standards.


"PLATTER PUSSES"

"Platter Pusses," made by Robins Industries Corp., are felt- flocked leatherette discs which are designed to keep fingerprints off your hi -fi records. You just fold one in your hand and pick up a record without touching it with your fingers. The inexpensive "Platter Pusses" are packaged in lots of 12.


TEST LEAD HOLDER

A test lead rack designed to store patch cords and cable assemblies has been announced by Pomona Electronics Co., Inc. The rack simplifies the job of locating a particular test lead by making it readily accessible. Fabri- cated from cold rolled steel, with baked enam-

POPULAR ELECTRONICS

What most people don't know about hi -fi kits could fill a book.

This one. (And it's free!) The New

Kit Builders 11Ij, nual

FREE! $1.50 VALUE! 32 PAGES! The New Kit Builder's Manual is a completely new version of the authoritative Fisher guide to high -fidelity kit construction. It is new in format, twice as long in content, and contains detailed specifications of all Fisher StrataKits. Here is an introduction to kit building presented in a manner so nontechnical and lucid, even your wife will understand it. Included are comprehensive, illustrated articles on every phase of assembly, wiring and soldering. The New Kit Builder's Manual is the handiest tool a do-it - yourself audiophile can have: the first thing you need before investing in stereo amplifier, tuner or loudspeaker kits.

Mail this coupon today for your free copy of The New Kit Builder's Manual! r

Fisher Radio Corporation 1011 11 -40 45th Road, Long Island City, N.Y. 11101

Please send me The New Kit Builder's Manual without charge or obligation.

Name

Address

City State J

OVERSEAS RESIDENTS PLEASE WRITE TO i iSNER RADIO INTERNATIONAL. iNO.. LONG ISLAND Ei v.r. t

The Fisher November, 1965 CIRCLE NO. 17 ON READER SERVICE PAGE 23

PRODUCTS (Continued from page 22 )

el finish, the unit accepts cables up to 0.210 inch in diameter. Mounting holes are provided for easy installation on any vertical surface.


SOLID -STATE CB TRANSCEIVER

Could your car use a 23- channel transceiver that takes less current than an ordinary dashboard clock and will function even when the car battery is so low that it won't turn over the engine? According to Pearce -Simp- son, Inc., its solid -state "DIRECTOR" will do

both of those things. The "DIRECTOR" requires no warm -up period, and features a dual- conversion superhet receiver and a special high -gain audio power amplifier. It comes complete with crystals and a universal, all - angle- mounting bracket on a slide rail.


COMPACT SPEAKER SYSTEM

Only 6';." high x 13" n," wide x 4" deep, the Jensen X -11A two -way speaker system is intended for use as an extension speaker. High

frequency response is 14,000 cycles, and full room volume is possible with low -power amplifiers. Fea- tures include a volume control and built -in

hangers for easy wall mounting. Having an impedance of 8 ohms, the X -11A can be used with amplifiers having 4, 8, or 16 ohms output.


INTERCHANGEABLE TV ANTENNA

The " Starfire" is claimed to be the only antenna on the market that can be used with either 75- or 300 -ohm transmission line- /cif-hour matching transformers. Announced by Kay -Townes Antenna Company. it's a high -gain, 11- element, gold- anodized unit for local and fringe reception, and especially designed for color reception.


CALIBRATION STANDARD CARTRIDGES

Built right into the stylus of each Stanton 581 calibration standard cartridge is a corn-

24

pletely integrated dust -removing device. The 581 -otherwise known as the "LONGHAIR" cartridge -has a free -riding long -haired brush extending from the front of the plastic stylus V- guard. It engages the grooves in advance of the stylus and prevents any collection of lint or dust on the stylus tip -without affecting delicate tracking forces. The 581 is available in three models.


CB BEAM ANTENNA

Constructed of high -tensile strength aluminum, the A -411 -S 4- element "Scotch- Master" beam is a sturdy, bi- directional base station antenna announced by Mosley Electronics, Inc. It boasts a VSWR of 1.5/1 or better and is gamma- matched. Gain is 8.7 db over 1/4- wave dipole or 11.2 db compared to an iso- tropic antenna. And if you stack two A -411 -S antennas together, you get an additional 3 db gain. A stacking kit is available.


TRANSISTORIZED INTERCOM

Up to ten master stations can be connected to the Lafayette Model USI -10 transistorized

intercom, and up to five private conversations can take place si- multaneously. A special indicator circuit provides a silent visual signal of a call by a particular station; if a

"call" is received while the unit is in communication, the indicator lamp remains lit until the "call" is answered. Communication is possible up to 1000 feet.


WORLD TIME WRISTWATCH

Hams everywhere can tell the time anywhere on the five continents just by glancing at Seiko's new 17- jewel, self- winding world time wristwatch. There is just one large, easy -to- read dial which gives the local time in every global time zone. There are no adjustments to be made, and there is no need for mental arithmetic or reference to any charts. A synchro- nized permanent color code indicates whether the time in any overseas zone is day (blue) or night (black), and an automatic calendar shows the date large and clear. The wristwatch never needs winding if it is worn daily.


POPULAR ELECTRONICS

THE TURNER TRANSISTORIZED

WITH VARIABLE OUTPUT LEVEL

VOLUME CONTROL

Now, from Turner comes the very finest base station microphone ever designed. The +El features a two transistor pre -amp with volume control to give you up to 50 times the output level you now have. Yes, just dial your desired signal for maximum modulation all the time - every time. You can work close or far away from this microphone, or change the output for a

big or little voice. Eventually, all sets lose some of their initial power. Turner's +E3 puts

the zip back into your set and keeps it up to full strength at all times! The +El has tailored frequency response of 300 -3500 c.p.s. This means

the best and clearest voice transmissions with knocked down local noise interference.

Exclusive touch -to -talk or lock on -off switching - the +E3 works with all tube or transistor sets regardless of switching requirements or type.

Ask your dealer about the new +E3. LIST PRICE $49.50

THE TURNER MICROPHONE COMPANY

901 17th Street N.E. Cedar Rapids, Iowa

Available in Canada

Export: Ad Auriema, Inc., 85 Broad Street, New York 4, N.Y.


"New set of wheels? 1 hit the jackpot!"

"Ever since I can remember l've been hung up on anything that rolls. From skates

to scooters to my own home -made custom job. And l've always wanted

more wheels.

"So I joined the Army. Jackpot! I

found more wheels, more different kinds of wheels than I ever thought

existed. Wheels. Treads. Science - fiction rigs running on rubber pillows. Even a mechanical mule. "And I get a chance to work on

all of them. That's part of being an Army mechanic.

"Next month I'm off to see the world. And some of the wildest

jobs that ever rolled." An Army enlistment has been the turning point for many men. And it can be for you. It can give you the chance to learn any one of over 300 skills, skills you can build your life on. You can travel to countries and places you might never see otherwise. And you'll be proud of what

you're doing.

Look into what the Army has to offer. You'll find

there's more for you in today's action

111 v "tl 'T

rmv

DRILL HOLES IN VTVM FOR EASY CALIBRATION

'L'o calibrate the EICO 221 or similar type VTVM, you must first remove the unit from its carrying case, since the calibration controls are mounted inside the case. However, if you drill holes through the top of the case in line with the controls, you will be able to leave the unit in place when you calibrate. The holes should be large enough to pass a small screwdriver after grom- mets are inserted for a finished appearance. Calibra- tion for d.c. can be readily accom- plished by using a mercury battery as a reference; each cell puts out 1.35 volts, even after it has aged greatly. For a.c. adjustments, use an accurate a.c. meter for comparison. The line voltage, while nominally 117 volts, does vary from time to time.

-Walter Robson, Jr.

RELAY GATHERING DUST? BOTTLE IT UP FOR PROTECTION

Relays that must be used in dusty locations are subject to failures resulting from dirty contacts. To prevent such failures, enclose your relay in an airtight housing. Suitable

housings can be made from a variety of con- tainers such as screw cap jars, coffee cans with plastic snap -on covers, or for the really small relay, small vials. The lid, or cap, of the container with relay attached is mounted on the

chassis, and the wiring for the relay is run through a hole in the cap which is then sealed. Finally, the container is screwed or snapped

Here's how to find out what the Army can do for you The quickest way is to go see your local Army Recruiter. He'll answer any questions you have about your opportunities in the Army. If he doesn't have an answer right there, he'll get it for you. And it'll be a straight answer. After all, it's his job to be sure the Army's the right place for you. He knows where the opportunities are...and can tell you where you'll fit in. You can easily find your local Army Recruit- er listed in your telephone book. Call him today. And, in the meantime, fill out this coupon and you'll receive a copy of the helpful and informative 40 -page booklet, The Secret of Getting Ahead. No obligation on your part, of course.

Army PH 1

DRTU'.ITIE

Box 1040 Westbury, N. Y. 11591

Please rush me your 40 -page booklet, The Secret of Getting Ahead."

NAME AGE_ ADDRESS

CITY STATE ZIP CODE

PHONE EDUCATION

so


More heat

where it counts ' for greater

soldering efficiency - It's impossible to get the performance you expect from a soldering gun unless it converts its rated watts into heat at the tip.

Weller guns deliver the most heat per rated watt. They melt solder faster, and assure more reliable soldered connections than any other soldering guns.

For the most efficient heat, fastest heat, and exclusive trigger -controlled dual heat - insist on Weller.

Weller Dual Heat Guns and Kits come in wattage ranges from 100 to 325, priced from $6.95 to $12.95 list.

WELLER ELECTRIC CORP., EASTON, PA.

WORLD LEADER IN SOLDERING TECHNOLOGY


28

TIPS (Continued from page 27)

onto the cap to effectively seal the relay against dust. -Wm. B. Ra.crn assen

TRANSISTOR ADAPTER SPEEDS TESTS

AND ELIMINATES SOLDERING

To avoid soldering and unsoldering in an experimental circuit or when you are trying to find a transistor that will work in your circuit, you can build this inexpensive adapter. It will enable you to quickly plug in your transistors. Simply take a %"-thick block of

wood measuring approx'mately 32" x 3" and attach it to a metal plate of the same size. Mount a transistor socket on the plate and connect the socket terminals to three Fahne- stock clips on the block as shown. Material and dimensions are not critical.

-James O. Fishbeck

GELATIN MOLDS AND RUBBER BALLS

SHOCK -MOUNT HI -FI EQUIPMENT

Make use of several homemade air suspension mounts to isolate your record player or other hi -fi equipment from annoying vibra- tions - particularly those which travel f along the floor and hi -fi furniture. Each mount consists of a small gelatin mold, a woodscrew, a washer, and an air - filled rubber ball 4I LL /HDLE just large enough to fit into the wide end of the mold. i01Iflllj1L11MOLD

Drill a hole in the bottom of the mold just large enough to accommodate the screw. Place the washer between the screw head and mold, and screw the mold into place on a side of the base. Then cement the rubber ball in place inside the mold. If the sides of the base are too thin to hold the screws, you can build up the cabinet with a block of wood. -Harry Goldman

iW DDDSCBEW

AIR FILLED BUBBEB BALL

POPULAR ELECTRONICS

SCOTT

Zip through Scott's new solid state FM stereo tuner i kit in one afternoon

Four to six hours! That's all you need to zip through Scott's new LT -112 FM stereo tuner kit. Start after lunch -enjoy superb stereo at dinner.

Scott solid state circuitry is the key to the LT -112's superior performance. Costly silicon transistors give performance unapproached by any other kit on the market. The LT -112 is kit - brother to Scott's best -selling 312 solid state stereo tuner, of which Audio said, "... one of the finest tuners anywhere."

Your LT -112 arrives with all critical circuitry prewired, pre- tested, prealigned, and mounted on heavy -duty printed circuit boards. Scott's ex-

elusive life -size, full -color construction book details every step ... makes perfect wiring almost automatic.

You'd never believe a kit so easy to build could be so packed with features. Built into the LT -112 is a new Scott invention ... the Tri- modulation meter, used for a Signal Strength Indicator, Zero Center Indicator, and Align- ment Meter.

See your Scott dealer today, and pick up an LT -112 tuner kit ... $179.95 plus one enjoyable afternoon will net you a lifetime of listening pleasure.

MEW

0

Ve IN MI

For Complete information on Scott's kits & components write: Dept. 520 -11, H. H. Scott, Inc., 111 Powdermill Road, Maynard, Mass. Export: Scott International, Maynard, Mass. Cable HIFI. Prices slightly higher west of Rockies.

Prices and specifications subject to change without notice. CIRCLE NO. 39 ON READER SERVICE PAGE

November, 1965 29

BY

Ï RAYTHEON

AND

PERFECT PAIR...

SOLID STATE...

SOLID STATEMENT

QUOTE:

Ray -tel, all- transistor C -B radio line, broadest of any in scope, priced to re- flect full value at all equipment levels.

This fine line ranges from the sophisticated, full- feature 11- channel TWR -5

intended for personal and business communication systems, to the diminutive 5- channel TWR -7, price and performance peer of all the solid -state mobile radios.

We will be pleased indeed to send you complete details.

Please send details on Ray -tel TWR -5 and TWR -7.

Name

Number Street

City State Zip Code

RAY -TEL . 213 E. Grand Ave., So. San Francisco. Calif. 94080


ELECTRON ICS

LIBRARY RECEIVING TUBE SPECIFICATIONS & SUBSTITUTIONS Having made a "name" for itself by publishing several cross indexes of transistors. Techpress, Inc., has now invaded the vacuum -tube field. This book lists the specifications of more than 2000 American and foreign tubes. The style of the listing is similar to that successfully employed by Techpress in its previous books. Details on tubes are tabulated according to type number and according to general family characteristics ( diode, triode, etc.) . Special codes and symbols are used in the tables to simplify the presentation. This book is likely to be of great value to designers, or experimenters wanting to upgrade equipment. Published by Techpress. Inc., Brouvnsburg. Ind. 46112. Soft cover. 140 pages. $1.95.

1;.r

SOLAR CELL & PHOTOCELL EXPERIMENTERS GUIDE

by Stu Hoberman

The basic objective of this latest book in the Howard W. Sams "Photofact" series is to demonstrate the theory and application of light- sensitive devices by actually con- structing projects that rely on them for their operation. How and why these devices operate as they do is explained, and you are told what type to choose for particular applications, and whether to use sun- light, artificial light, or other light sources to activate the devices. Many variations of the projects covered here are possible; this guide furnishes the basics, and you provide the innovations. Published by Howard W. Srnns cf Co.. Inc.. 4300 West 62 St., Indianapolis 6, Ind. Soft cover. 128 pages. $2.95.

© m BASIC ELECTRONICS (Second Edition)

by Bernard Grob

Every once in a while a textbook on electronics is published that is really outstanding. Such a book may be different because of the material preparation, art layout and


FWVC°0 CANTENNASG FOR UHF, VHF, FM RECEPTION

The one antenna that does the work of 3! Gives startlingly clear black and white pictures and beautiful color on

both UHF and VHF television channels - plus the finest in stereophonic and monophonic sound reproduction.

FINCO Model UVF -18- $42.50 list FINCO Model UVF -16- $30.50 list FINCO Model UVF -10- 518.50 list

FINCO's Color -Ve -Log challenges all competition! Its

swept -element design assures the finest in brilliant color and sharply defined black and white television recep-

tion - as well as superb FM monaural and stereo quality

FINCO Model VL- 18- $54.50 list FINCO Model VL- 15- $46.95 list FINCO Model VL -7- $23.95 list FINCO Model VL -5 -$16.95 list

Featuring FINCO's exclusive Gold Corodizing

FINCO COLOR -VE -LOG Prices and specifications subject to change without notice

THE FINNEY COMPANY 34 W. Interstate Street Bedford, Ohio Write for beautiful color brochures Number 20 -322, and 20 -307, Dept, PE


November, 1965 31

New 96 -page book gives step -by -step instructions for

SIMPLE

ELECTRONIC

PROJECTS You Can Build NOW!

How would you like to make a sun -powered radio, or a walkie- talkie, an intercom, a broadcast station, a burglar alarm, a code transmitter, or any one of 50 exciting, easy -to -build projects? It's simple - the Semitronics way.

Easy -to -build projects described in simple language with clear diagrams. No technical background needed - just pliers, screwdriver and soldering iron. All parts inexpensive, re- usable for many projects

IDEAL FOR BEGINNERS OF ALL AGES With the new Semitronics handbook "Electronic Projects," any student, beginner or hobbyist can have the fun and excitement of building electronic projects that work - even if you never worked with electronics before. Semitronics makes it simple. with this illustrated handbook, and easy -to -find parts, all available at low cost from your dealer's Semitronics Electronics Center.

THE FUN WAY TO LEARN This educational science program provides an exciting and fascinating introduction to electronics and the space age. Students will find the Semi - tronics program especially appealing, as they learn new facts in a practical, enjoyable way. Try your first project now - just for the fun of it.

LOOK for the Semitronics Electronics ELECTRONIC Center at Your Local Dealer

PROJECTS OR SEND $2 for your Projects Book ...... (Includes postage and handling) TO:

I Name

PEll

Semi oñlcs Corp. 265 Canal Street, New York, N. Y. 10013

Enclosed is $ send me copies of the Semitron 50- Projects Book postpaid.

Address

City /State Zip J CIRCLE NO. 49 ON READER SERVICE PAGE

LIBRARY (Continued from page 30 )

handling of illustrations, or because the idea is novel. Author Grob has arrived at just about the ideal combination of the above ingredients in the second edition of Basic Electronics. Obviously a classroom text, the organization of the material, illustrations, etc., is so complete that this book can be safely recommended to any beginner. Your reviewer was particularly impressed by the clever use of gray tones in circuit diagrams and formulas to identify essential components or answers to problems. Very highly recommended. Publishcd by McGraw -Hill Book Co., 330 West 42 St., New York, N.Y. 10036. Hard corer. 588 payes. $7.50.

G 0 0 BASIC ELECTRONICS: "AUTOTEXT " -A PROGRAMMED COURSE IN CIRCUITS

by RCA Institutes, Inc., and edited by Jack W. Friedman, Harry G. Rise,

and Gerald McGinty

A programmed course in basic electronics for beginners with no previous knowledge or experience in electronics, this book covers d.c. and a.c. circuits, principles of reso- nance and filters, and prepares the student for the study of tube and transistor circuits. It is actually a work book -the text consists of a comprehensive series of questions to be answered right in the book. The student can then compare his response immediately with answers which appear on tear -out sheets in the back of the book. The home -study student should find both text and illustrations easy to understand. and with an average amount of application should be able to learn how to read schematics. and to have a working knowledge of capacitors, resistors, coils, transformers, etc. Very highly recommended.

Published by Prentice -Hall. Inc., Englewood Cliffs, N. J. Hard corer. .,311 pages. $13.00.

FREE LITERATURE

More of everything for everyone is claimed for Allied Radio's new 1966 catalog, including what's new in the world of Knight -Kits. It contains 508 value- packed pages. For your copy, write to Allied Radio, Dept. 3 -J. 100 N. Western Ave., Chicago, Ill. 60680 .. .

New -Tronics Corporation, 3455 Vega Ave., Cleveland, Ohio 44113, has just issued a new catalog on its expanded line of CB antennas and accessories. A number of new mobile antennas are illustrated and described as well as base station models -- 32 POPULAR ELECTRONICS

The BIG Difference in

Citizens Band Units

JUHNiUN'5

Vs Os Ws Op so so Os

%NAM:CUED 1

fig 1113111040% ' For personal or business use, no other equipment equals the day -in day -out dependability of Johnson "Messenger "Two -Way Radios. "Messengers" are designed to deliver maximum performance, even under extreme operating conditions. Before you buy -take a long look at the Johnson quality line -or better yet, talk to any "Messenger" owner. You'll see why dollar for dollar, Johnson is your best buy! Easy to install, easy to operate, license issued on request.

,lUHNSUN

November, 1965

See your nearest Johnson Dealer Distributor or write for complete information.

E. F. JOHNSON COMPANY 2452 TENTH AVE. S.W. WASECA, MINN. 5609;


SOMEONE SHOULD DEVELOP AN EASY WAY

TO LEARN ELECTRONICS AT HOME

RCA INSTITUTES DID!

Here is a whole new approach to learning electronics at home! RCA Institutes, one of the nations' largest schools devoted to electronics, has developed a faster, easier way for you to gain the skills and

the knowledge you need for the career of your choice. Here for the first time, is a

student -proved, scientifically designed way

to learn. If you have had any doubts in

the past about home training in electronics -if you have hesitated because you thought you might not be able to keep up -or that electronics was too complicated to learn - here is your answer! Read how

RCA Institutes has revolutionized its entire home training ideas!


NEW CAREER PROGRAMS

BEGIN WITH "AUTOTEXT" INSTRUCTION METHODS

Start to learn the field of your choice immediately!

No previous training or experience in electronics needed!

With this new revolutionized method of home training you pick the career of your choice -and RCA Institutes trains you for it. RCA's Career Programs assure you that everything you learn will help you go directly to the field that you have chosen! No wasted time learning things you'll never use on the job! The Career Program you choose is especially designed to get you into that career in the fastest, easiest possible way!

And each Career Program starts with the amazing "AUTOTEXT" Programmed Instruction Method -the new, faster way to learn that's almost automatic! "AUTO -

TEXT" helps even those who have had trouble with conventional home training methods in the past. This is the "Space Age" way to learn everything you need to know with the least amount of time and effort.

CHOOSE A CAREER PROGRAM NOW

Your next stop may be the job of your choice. Each one of these RCA Institutes Career Programs is a complete unit. It contains the know -how you need to step into a profitable career. Here are the names of the programs and the kinds of jobs they train you for. Which one is for you? Television Servicing. Prepares you for a

career as a TV Technician /Serviceman; Master Antenna Systems Technician; TV Laboratory Technician; Educational TV Technician. FCC License Preparation. For those who want to become TV Station Engineers, Communications Laboratory Techni- cians, or Field Engineers. Automation Electronics. Gets you ready to be an Automation Electronics Tech- nician; Manufacturer's Representative; Industrial Electronics Technician. Automatic Controls. Prepares you to be an Automatic Controls Electronics Tech- nician; Industrial Laboratory Technician; Maintenance Technician; Field Engineer. Digital Techniques. For a career as a Digital Techniques Electronics Techni- cian; Industrial Electronics Technician; Industrial Laboratory Technician.

Telecommunications. For a job as TV Sta- tion Engineer, Mobile Communications Technician, Marine Radio Technician. Industrial Electronics. For jobs as In- dustrial Electronics Technicians; Field Engineers; Maintenance Technicians; In- dustrial Laboratory Technicians. Nuclear Instrumentation. For those who want careers as Nuclear Instrumentation Electronics Technicians; Industrial Lab- oratory Technicians; Industrial Electron- ics Technicians. Solid State Electronics. Become a specialist in the Semiconductor Field. Electronics Drafting. Junior Draftsman, Junior Technical Illustrator; Parts In- spector; Design Draftsman Trainee Chartist.

SEPARATE COURSES In addition, in order to meet specific needs, RCA Institutes offers a wide variety of separate courses which may be taken independently of the Career Pro- grams, on all subjects from Electronics Fundamentals to Computer Program- ming. Complete information will be sent with your other materials.

LIBERAL TUITION PLAN RCA offers you a unique Liberal Tuition Plan -your most economical way to learn. You pay for lessons only as you order them. No long term contracts. If you wish to stop your training for any reason, you may do so and not owe one cent until you resume the course.

VALUABLE EQUIPMENT You receive valuable equipment to keep and use on the job -and you never have to take apart one piece to build another. New - Programmed Electronics Bread- board. You now will receive a scientifically programmed electronic bread-

C>

board with your study material. This breadboard provides limitless experi- mentation with basic electrical and elec. tronic circuits involving vacuum tubes and transistors and includes the construction of a working signal generator and superheterodyne AM Receiver.

Bonus From RCA - Multimeter and Oscilloscope Kits. At no additional cost, you will receive with every RCA Institutes Career Program the instruments and kit material you need to build a multimeter and oscilloscope. The inclusion of both these kits is an RCA extra.

CLASSROOM TRAINING ALSO AVAILABLE RCA Institutes maintains one of the largest schools of its kind in New York City where classroom and laboratory train ing is available in day or evening ses- sions. You may be admitted without any previous technical training; preparatory courses are available if you haven't com pleted high school. Coeducational classes start four times a year.

FREE PLACEMENT SERVICE In recent years, 9 out of 10 Resident School students who used the Free Placement Service had their jobs waiting for them when they graduated. And many of these jobs were with top com panies in the field -such as IBM, Bell Telephone Labs, General Electric, RCA, and radio and TV stations and other communications systems throughout the world.

SEND ATTACHED POSTAGE PAID CARD FOR COMPLETE INFORMATION, NO OB- LIGATION. NO SALESMAN WILL CALL. FREE BOOK INCLUDED. CHECK HOME STUDY OR CLASSROOM TRAINING.

RCA INSTITUTES, IRC.,Dept. PE -N5 A Service of Radio Corporation of America 350 West 4th St., New York, N.Y. 10014

The Most Trusted Name in Electronics

November, 1965 37

You earn your FCC

First Class License

Fr RST CLASS .. .»»,a r... w mow

owe ...m. ears . en+en

or your money back! THERE'S A WORLD OF OPPORTUNITY FOR THE MAN WITH AN FCC LICENSE

All it takes is a few spare hours a week and NRI's FCC License Course to open the way to increased opportunities in Commu- nications. With an FCC License, you're ready to operate, service and install transmitting equipment used in aviation, broadcasting, marine, mobile and Citizens -Band communications.

What does it take? Men with absolutely no training or experience in Electronics complete the course in 10 months. A Tech- nician or man with some background can easily cut that time in half. And because NRI has a greater enrollment than any other school of its type, training costs you less than comparable courses offered by other schools. Further, YOU MUST PASS your FCC exams or NRI refunds your tuition in full.

Get full details today about NRI FCC License Course plus 9

other home -study instruction plans offered by NRI, oldest and largest school of its kind. Mail coupon for free catalog. There's no obligation. No salesman will call. NATIONAL RADIO INSTITUTE, Washington, D.C.

38

MAIL NOW for FREE CATALOG

NATIONAL RADIO INSTITUTE Electronics Division Washington, D. C. 20016 21 -115

Please send me complete information on FCC License Training and other NRI courses. as checked below. (No salesman will call.)

FCC License LI Radio -TV Servicing Complete Communications industrial Electronics Aviation Communications Electronics for Automation Marine Communications H Basic Electronics Mobile Communications CA Math for Electronics

Name Age PLEASE PAINT

Address

City State Zip ACCREDITED MEMBER NATIONAL HOME STUDY COUNCIL

SATELLITES ON THE AIR

The following satellites were in transmitting as this issue closed.

Echo 2 136.020 mc. Alouette" 136.077 mc. Explorer 23 :: 136.080 mc. Explorer 28 .136.125 mc. Relay 1** 136.140 mc. Relay 2 136.142 mc. Explorer 21 136.145 mc. Echo 2 136.170 mc. Explorer 22 °° 136.171 mc. OGO 1*" 136.200 mc. Tiros 8 136.231 mc. Tiros 9" "' 136.231 mc. Tiros 10 136.232 mc. Tiros 7 136.233 mc. Explorer 26 136.275 mc. Explorer 25 136.292 mc. Explorer 20" 136.350 mc. Pegasus 1" 136.410 mc. Pegasus 2 .136.410 mc. Pegasus 3 136.410 mc. Syncom 2"0 136.468 mc. Syncom 3" 136.470 mc. Ariel 2 .. _ 136.558 mc. Alouette' : . 136.593 mc. Relay 2"0 136.620 mc. Relay 1 136.621 mc. 1964 83C 136.650 mc. 1963 33C (USA) 136.651 mc. Explorer 20° 136.680 mc. Explorer 24 136.710 mc. OSO 2 136.712 mc. Explorer 27 136.740 mc. 1965 58C (USA) 136.768 mc. Gravity Gradient (USA) 136.800 mc. EGRS Ill .136.840 mc. Solar Radiation 136.886 mc. Pegasus 1 136.890 mc. Tiros 7 136.924 mc. Tiros 8 136.923 mc. Syncom 2" 136.980 mc.

'IIansulit.s only ui,u ground cuulmand This listing does not include all of the satellites in orbit -many of which no longer are transmitting, or transmit erratic, very weak signals. Satellites of the Soviet Union generally use tracking and telemetry frequencies in the band between 19.990 and 20.010 mc. Exact frequencies of some Soviet satellites are broadcast by Radio Moscow immediately after launching. In orbit are Cosmos 41, 42, 43, 44, 49, 51, 53, 54, 55, 56, 58, 61, 62, 63, 70, 71, 72, 73, 74, 75, 78.

orbit and

POPULAR ELECTRONICS

SMALL PACKAGE

BIG PUNCH i

INTERNATIONAL Model MO TRANSCEIVER For CITIZENS RADIO SERVICE

New Compact Size

New Solid -State Crystal Switching Circuit New Photo -Control Volume Circuit New Remote Control With Matching Microphone

The International Model MO Citi- zens Radio transceiver, custom designed for mobile installation, provides instant push -to -talk crystal controlled operation on any 6 channels with full 5 watts power input. The new compact control head provides complete remote controlled operation. All circuits are dc using solid -state crystal switching. The operating channel is indicated by an illuminated button on the control head. Tubes and silicon transistors are combined to provide a rugged trouble -free circuit.

FCC Citizens Radio license required. All use must conform with Part 95, FCC Rules and Regulations.

The complete transceiver includes: a remote control head (about the size of a cigarette package), matching white microphone, new compact transmitting / receiving unit which may be conveniently installed in the trunk, and a matching white speaker which mounts under the dash. Oper- ates from 12 vdc negative ground power source. Other power input units are available on special order.

See the "all new" International Model MO at your dealer today.

INTERNATIONAL

CRYSTAL MFG. CO., INC. '7B NO. LEE OKLA. CITY. OKLA. 73102


BUILD A MODEL RACE CAR MOTOR SPEED CONTROL

13 OTHER EXCITING SCR CONTROL CIRCUITS WITH HUNDREDS OF USEFUL APPL CATIONS

Here's what you've been waiting for...now, you can build your own silicon controlled- rectifier control circuits. Start with RCA's Basic Experi- menter's Kit (KD2105). With it, you can build a model race car speed control, a universal motor speed control, or eight other interesting circuits. Add -on Light Sensor and Heat Sensor Kits (KD2106 and KD2110) enable you to build 4 more electronic control circuits for hundreds of useful applications around the house, hobby shop, and garage.

The 80 -page, illustrated RCA Experimenter's Manual (KM -70) will familiarize you with the theory and operation of solid -state components in the kits. At the same time, it will give you complete detailed information on all 14 circuits including schematic diagrams, circuit descriptions, and construction details, as well as photographs of the circuits as easy -to- follow assembly guides.

Here is what you can make... 1. Electronic Timer. 2. Electronic Time Delay Switch. 3. Electronic Flasher. 4. Battery Charger (12 volts). 5. Battery Charger (6 volts). 6. Model Race Car and Railroad Speed Control. 7. Light - operated Switch (Turn -on). 8. Light- operated Switch (Turn -off). 9. Electronic Heat Control (Turn -on). 10. Electronic Heat Control (Turn -off). 11. Over- load Switch. 12. Electronic Synchronous Switch. 13. Universal Motor Speed Control. 14. Lamp Dimmer.

Here is what You Need... RCA Basic Experimenter's Kit (KD2105) One

Silicon Controlled -Rectifier; Two Transistors; Five Rectifiers.

RCA Experimenter's Manual (KM -70) 80 Illus. trated Pages; 14 Circuits and How to Build Them.

RCA Add -On Light Sensor Kit (KD2106) One Photocell for light- operated switches.

RCA Add -on Heat Sensor Kit (KD2110) Three Thermistors, special solder for heat -control circuits.

Plus readily available standard components.

If you want to build one circuit or all 14, check with your RCA Distributor where kits and RCA Experi- menter's Manual are on display. He'll be glad to help you select the kit or kits for the solid -state circuit you have in mind. Dc it today! Available from your RCA seniicottductor distributor RCA ELECTRONIC COMPONENTS AND DEVICES. HARRISON, N. J.

The Most Trusted Name in Electronics



H

COVER STORY

fl TEN YEARS LACER By LAWRENCE LEKASHMAN

Vice President, Sales Electro- Voice, Inc.

A QUICK SUMMARY OF THE LAST DECADE

IN HI -FI AND THE IMPACT OF STEREO

NOSTALGIC PHOTOS AND CAPTIONS FOR HI -FI GEAR BY THE EDITOR

BETWEEN 1956 and 1965 all the sci- ences and technologies exposed to

the public view have advanced by Her- culean leaps. While all pall in comparison to space exploration, too frequently the yardstick for progress is the dramatic or awesome achievement. Obviously, the entire field of electronics has progressed throughout the past decade. Electro- acoustics -the conversion of sound into electricity or electricity into sound - traverses many applications including military communications, long- distance telephone, sonar, seismology, etc. Less sophisticated, but most important for the pleasure it brings to so many, is the reproduction of music with optimum fidelity.

Links in a Chain. If each link in the chain of hi -fi sound reproduction could be isolated one from the other, a ten - year review would be relatively simple. But each link in the hi -fi chain is related to the others and the development of one affects all.

The most obvious example is the emergence of the transistor as a medium - priced practical device holding out the greatest number of advantages to the hi -fi sound engineer. The transistor was not developed for hi -fi, yet it is in this very field that the transistor will achieve its most notable and significant application for the average consumer.

On the other end of the scale, subtle November, 1965 41

developments have taken place gradually over the past decade to which all but the most sophisticated technician might be oblivious. Look at, for example, the automatic record changers and transcription players. At the end of a decade of progress, these units still change records, they track the grooves, and they shut themselves off automatically. But mechanical engineers have met the demands of hi -fi sound reproduction and have developed better materials, more precise machine fit, ingenious designs, and quality control that easily permits a record changer to perform as well, or better than, the transcription player of 10 years ago.

The Speaker. Certainly the most critical element in any hi -fi system is the loudspeaker: critical, because it is impossible for any system to reproduce sound one iota better than the speaker to which it is attached; critical, because the speaker is a component selected by subjective evaluation; and critical, because of the misinformation circulated

In the scramble to advance from mono to stereo (in 1958), there were numerous attempts to combine the old and the new. This Fairchild 248 stereo preamplifier sold for a whopping $239.50. It obviously consisted of two separate preamplifiers housed in the same wraparound. Controls at right -hand side of unit were for Master Volume and selection of output functions.

about the performance of loudspeakers. In the past decade, no sound -wave re-

producer has emerged to challenge the efficiency, power -handling ability, and wide audio range of the dynamic speaker. Whether we see it in its familiar cone design, or as a compression driver or dome radiator, this superlative repro- ducer is unlikely to be superseded in the next decade by gas- operated speakers, electrostatic speakers, or other devices.

Dynamic speaker design has not stood still during the past decade. Even the most conventional speaker has been improved through the use of lighter weight, but more powerful magnets; improved cone suspension and voice coil design; and sturdier, non -resonant baskets. Im- provements were dictated by the requirements of stereo and the demand for two channels of full- range, well -balanced sound.

This demand also resulted in the development and exploitation of the so- called bookshelf -type speaker system. Possibly two- thirds of the speaker systems sold today are of the shelf type. A

Almost every speaker has some directional characteristics, but Jensen's SS -100 was a bona -fide attempt to use "direction" to solve the stereo listening area problem. In the SS -100, the mid -range and treble speaker were mounted on a platform and could be aimed at the audience.

This is the speaker system that never was -the "Integrand."

Designed around a servo response mech- anism, it was supposed to adjust itself to room acoustics for better

reproduction. It didn't.

POPULAR ELECTRONICS

Miniature loading slots at the bottom of this system

helped produce reasonably good sound bass. A product of

one man, Stewart Hegeuran, this EICO HFS -2 also featured

a free -fixating tweeter for near 360° treble dispersion,.

The HFS -2 was years ahead of its time (1957), but those that

liked its sound were unrestrained in their praise

The " Ionovac'" has had a colorful history, but little public

acceptance. This version was offered to hi -fi enthusiasts

about five years ago by the DuKane Corporation. Capable

of crystal -clear treble note reproduction from 3500 to

20 000 cycles,, the lonovac is now being sold in England and France.

43

The Stromberg- Carlson PR -498 was the ante- cedent of many simi-

lar lightweight, statically balanced,

single -pivot, and viscous -damped tone

arms. Permanently attached to a PR -500

turntable, this combination was once con-

sidered one of the best integrated arm/

turntable units.

Practically every hi -fi enthusiast has for-

gotten this all- transis- torized Vico 77 mono

amplifier. Introduced in 1957, the 77 left

much to be desired, but was a harbinger

of things to come.

decade ago, the acoustic -suspension, shelf -type speaker was just emerging, and small speaker systems were poor sound reproducers. Today's shelf -type speaker system is the result of a careful application of known principles -a fact established in a landmark patent suit in 1962.

Gone, but not completely forgotten, are the many speaker systems designed to "save" conversion costs from mono to stereo. "Gimmick" speakers for stereo are now a thing of the past and not likely to reappear in the next decade.

The Phono Cartridge. No single piece of a hi -fi system has had to undergo a more revolutionary change with the advent of stereo than the phono cartridge. While speakers and amplifiers simply doubled up, the cartridge with its single stylus now had to track grooves vertically and horizontally -or any combination of motion in between.

In this brief review, it is impossible to thoroughly cover the evolution from the "magnetic reluctance" cartridge of

G.E.'s PA -20 mono amplifier replaced

the "Convertible" which really came apart

in two pieces. The PA -20 was notorious

for heat generation.

44

1956 to today's superb transducer. Suf- fice it to say that the first stereo cartridges left much to be desired and that step -by -step improvement by many manufacturers now permits record reproduction comparable to the flatness and separation of channels of magnetic tape.

Frequency response, uniformity of manufacturing, excellent compliance, and stereo separation have been refined to the point where the phono cartridge - magnetic or ceramic -offers little opportunity for significant improvement. There will be a continuing search for transducing methods other than that used by the present cartridge, but all of these devices must employ a stylus -the single element that has seemingly reached the limit of the art. Possibly in the next decade we will see better sound - to -noise ratios and better impedance matching to transistorized circuits. The benefits of these improvements will be subtle and not earthshattering.

The Record Changer. During the past decade, the record changer has under-

gone pronounced improvements. By today's standards, a 10- year -old changer is a relic comparable to a "Model T." Among the lesser evils of the old changers were rumble -now intolerable in stereo reproduction -and high stylus tracking pressures. Rumble and flutter have both disappeared from the 1965 changer.

Stylus pressures are a fraction of those required 10 years ago and changer mechanisms no longer introduce lateral friction to wear down stereo record grooves. In fact, the greatest argument today for single -plate turntables is more one of convenience to the individual who plays single records, rather than the technical performance advantages. Oddly enough, Americans have yet to manufacture a changer equal in performance to those imported from Europe.

Tape Decks and Recorders. It would be improper to discuss changers without acknowledging the growing popularity of tape decks and tape recorders. In a manner similar to the changer, tape decks and recorders have been undergo- ing refinement in the past decade. The 15 -ips tape speed is almost a thing of the past and 7% ips is giving way to 3% ips.

Though tape does not have the wide public acceptance of the record changer, the cost of prerecorded tape is now competitive with stereo records. Lack of

The Heath Company had been instrumental in getting hi -fi off the ground with the famous William- son power amplifier. The AA -50 was one of the true integrated stereo amplifiers in the middle ground between tubes and all solid -state units.

public acceptance is probably due to the continuing search for the ideal tape packaging method -cartridge versus reel -to -reel.

The greatest and most significant improvements in tape playback have been in the design and fabrication of heads. A good tape deck with high -performance heads is a perfected instrument, capable of reproducing clean source material equivalent in sound to the original performance.

Electronics Hardware. Least vulnerable to subjective analysis and most easily defined in the engineering laboratory is the electronics portion of the hi -fi system. The transition in the past decade from mono to stereo placed great bur- dens on the manufacturer to deliver far more electronics hardware to the consumer at reasonable and competitive prices.

Today the typical stereo arrangement requires two preamplifiers, two power amplifiers, or two integrated amplifiers, all in one cabinet. With the advent of FM multiplexing and the retention of AM broadcasting, the receiver sections of stereo tuners and receivers have become alarmingly complex. These technical problems and how they were resolved would make a separate story, even though the impact of multiplexing upon the consumer has been modest.

The "revolution" in hi -fi, now upon us, is in the application of solid -state devices ( transistors, diodes, etc.) . The insistence by component manufacturers on the use of tubes at a time when "package" set manufacturers were wide- ly converting to transistors with their highly touted advantages of infinite life and minimum heat was most difficult to reconcile. The truth of the matter is that the use of transistors with characteristics of uniformity and performance suitable for incorporation in hi -fi equipment was simply prohibitively expensive until recent years. The story by Hans Fantel (page 47) explores the transition from tubes to transistors in 1964 -66.

November, 1965 45

Continuing Evolution. It will be apparent to the discerning reader that the 10 years of progress in the hi -fi field have been those of progress by "evolution" rather than by "revolution" -with the sole exception of the transistor. These 10 years have underscored a number of extremely significant facts.

One of the great advantages professed by the manufacturers of hi -fi equipment is the enormous flexibility they can offer. It is interesting to note that it would have been possible to update any hi -fi system throughout this 10 -year period without obsoleting all of the components. The gradual insertion of new

46

Hi -fi shows are held in most major cities. Those held in New York, Los Angeles, and San Francisco are sponsored by the Institute of High Fidelity. The shows provide an opportunity for the hi -fi enthusiast to meet and talk to the design engineers and company officials about their equipment. This photo illus- trates the introduction of Harmon -Kardon's stereo amplifier kits.

The contribution that kits have made to the hi -fi field can never be accu- rately estimated. Scott changed the kit building picture through use of color -coded wiring and pictorial diagrams.

and better products as the needs of the user dictated was practical at all times. The increase in popularity of hi -fi equipment has resulted in the manufacturing of finer components at less cost than in 1956.

While the prognosis for the future is hazardous. we can safely expect to see continuing evolution. There is little likelihood of radical developments in the method of sound reproduction or in the chain cf equipment that should make you hesitate to purchase or build a hi -fi system of your choice. Only the degree of sound perfection need determine how much you want to spend. --

POPULAR ELECTRONICS

By HANS FANTEL

Transistors are the magic

ingredients

IT'S BEEN a long time coming, but stereo /hi -fi has finally turned the cor-

ner and entered a new design era. From 1966 on, "solid state" will be the key to solid sound. Nearly every new tuner, hi -fi amplifier, stereo receiver or tape recorder introduced at this year's High Fidelity Show in New York City -the annual new product parade of the industry -was fully transistorized.

"Tubes have had it," commented one engineer after passing row after row of solid -state stereo equipment. And that about sums it up.

"So what else is new ?" you might ask, if you are the skeptical type. After all, transistors have been around for years. Ordinary pocket radios, cheap phonographs, and even TV sets became transistorized long ago. Why did hi -fi lag behind ?

Granted, some transistorized hi -fi gear has been on the market for almost five years. But most of the pre -1964 amplifiers sounded shrieky and had the incon- venient habit of dying young. By con-

November, 1965 47

Knight is the brand -name for equipment sold by Allied Radio. The Knight KN -376 stereo receiver features AM coverage as well as the usual FM /FM multiplexing. Rated at 35 wpc of music power, this 32 -transistor receiver goes for $270.00.

Scott's 388 solid -state AM /FM receiver is reported to be the first hi -fi component to use field -effect transistors in the FM tuner section. Use of such transistors eliminates cross modulation on weak signals. The 388 is rated at 40 wpc, and sells for less than $500.00.

trast, today's transistor designs equal or outperform any tube -type hi -fi. So the logical questions are: Why can they do it now when they couldn't before? Why did it take so long? And what's the advantage for the buyer?

Part of the overall answer is that hi -fi design engineers had to wait for the right type of transistors to become available at the right price. And then they had to learn how to design circuits around those transistors.

Design Problems. Up to now, few transistor types have been capable of satis- fying the exacting demands of true high fidelity sound reproduction. Transistor manufacturers, with their eyes on the top dollar, concentrated their efforts at making transistors for spacecraft and computers, paying little attention to the needs of the hi -fi fan. Most medium - price transistors were inherently too noisy for critical audio applications and they tended to lose much of the treble above 5000 cycles. Besides, they couldn't handle the power required for realistic hi -fi sound.

"They'd blow faster than fuses," re- calls Stewart Hegeman, who did pioneer work in transistorized audio. "The good - sounding transistors weren't rugged enough, and the rugged ones sounded awful."

This didn't matter much with pocket portables or tin -voiced low -fi phonographs, but for a long time it kept transistors out of genuine hi -fi applications. Most manufacturers stuck with tubes.

Several years ago a handful of hi -fi companies tried to scoop the audio market with marginal transistor products. But they discovered that fancy claims and sleek styling couldn't fool the ear. Most were soon out of business.

All this changed when the semiconductor manufacturers finally came up with new transistors capable of meeting the stringent specs of genuine high fidelity. Thanks to automated manufacturing techniques, the new transistors were more uniform in quality, more reliable in operation, and cheaper, too. Silicon transistors -offering much greater audio frequency bandwidth and power capability -had begun to replace the older germanium transistors.

But one more roadblock had to be overcome before the transistor's final takeover in audio. That obstacle existed in the minds of audio engineers. Too many still looked at the transistor merely as a substitute for a tube and tried to fit transistors into conventional circuits. In doing so, they threw away nearly all the advantages the transistor offers. It took time for engineers to learn to "think" in terms of solid -state circuitry.

De- Bugging Transistor Circuits. Off- hand, the advantages of the transistor seem obvious. Compared with tubes, the transistor is smaller, draws less power, develops practically no heat, takes no time to warm up, doesn't change characteristics with age -in fact, it doesn't wear out. Unlike tubes, transistors don't produce noise when exposed to vibration


L

1.1 ;l14ios

')1111, r.

Rated at 25 wpc, the Fisher 440 -T is the solid -state replacement for the

well -known 500 -C tube -type stereo receiver. Tagged at $329.50, the

440 -T has an unusual mode switching arrangement to permit playback of each

of the four tracks of a monophonic tape.

Builders report that they have constructed this EICO 3566 stereo receiver kit, which sells for $219.95, in 35 hours. The manufacturer is also offering a prewired and tested version for $325.00. The difference represents a

substantial saving for the kit builder.

-they are not microphonic -and shrug off accidental knocks. Besides, transistors are virtually hum -free, so that the music sings out against a background of almost complete silence.

Best of all, transistor amplifiers need no output transformer. Being low -impedance devices, transistors can feed their output directly into loudspeakers. By getting rid of the output transformer, transistors bypass one of the main bottlenecks to fidelity. As a result, transistorized hi -fi equipment usually sounds crisper and clearer than the older tube designs.

But before these advantages could be realized, transistor circuits had to be thoroughly de- bugged. Transistors were sensitive and had to be protected from overloads. Otherwise, their potentially long life would be cut short by the first loud bang in the music. And since some low- signal transistors react badly to heat, special circuits had to be devised to compensate for temperature variations.

None of this know -how came easy. Engineers discovered, for example, that it sometimes takes about four transistors to do the job of one tube. They tried shortcuts to make the product cheaper, but attentive listeners could always tell the difference.

One trouble that plagued early transistor designs was exactly the opposite of what bothered tube circuits. While tubes would distort at musical climaxes, the transistor jobs did fine on fortissimi. But at soft volume levels, the sound

tended to become harsh. This was especially noticeable during solo passages of sweet- voiced instruments, such as violin, cello, and clarinet.

For a long time, engineers were flum- moxed by this trouble. Finally, they tracked down its source. It was distortion produced by the "Class -B" operation of push -pull output transistors. In this circuit, two transistors work in tan- dem, each taking turns in developing power. Splitting up the work in this way prevents the transistors from overheat- ing and burning out. But the trick is to time each transistor's duty cycle so precisely that the alternate cycles match properly. Inaccurate timing of the Class B circuits results in either a momentary gap or a momentary overlap between the cycles. That's what was causing the curious harshness of the early transistor designs. Engineers finally devised special feedback correction to cancel out this type of distortion.

All this does not mean that tube equipment has been swept from the market entirely. Even such top -rank firms as Dynaco and Marantz still stick with tubes. Their attitude is that their present models offer outstanding performance and they see no reason to change them. Many manufacturers, in fact, offer both tube and solid -state equipment, but there is little doubt that the significant engineering advances are now being made in the transistor field.

Compact Quality. Ed Miller, who super- vises electronic design at Sherwood Elec-

November, 1965 49

The SA600 is rated at 65 watts to deliver full power at any frequency from 10 to 30,000 cycles. Manufactured by James B. Lansing Sound, Inc., it sells for $300.00.

Only $184 buys this 66 -watt stereo receiver kit from Heath. As a

bonus feature, the AR -13A has AM broadcast -band coverage. The tuner

sections are shipped prealigned.

tronic Laboratories in Chicago, says :

"Now we can pack more power into compact equipment. With cool- running transistors, we needn't worry about heat dissipation in high -power amplifiers, and lower operating temperatures make other components last longer." Miller also feels that the low hum levels attainable with transistors are an important design improvement.

Bob Furst, who designed Harman - Kardon's "Stratophonic" series of stereo receivers points to the outstanding stability of transistorized tuner circuits. "With solid -state r.f. circuits," he says, "we have virtually eliminated FM drift. I can turn the receiver off at night, and when I turn it back on in the morning, the station comes in right on the nose."

Speaking for KLH, a company that has always stressed compactness along with quality performance, John Milder says: "Solid -state design has enabled us to produce the first fully portable stereo system in a single suitcase -amplifier, speakers, turntable, FM stereo tuner - and all in a package you can lift with one hand."

The real payoff, however, is in the sound. Across the board, from budget models to deluxe designs, solid -state equipment offers an astonishing clarity that only the most expensive tube equipment has ever matched in the past. The term "transistor sound" has been coined to describe the sparkle, the crispness, and the tightly controlled bass typical of well- designed solid -state components.

E

With nine out of every ten hi -fi manufacturers introducing new solid -state equipment, we can but sample the wide variety shown at the recent hi -fi shows. This sampling is to give you an idea of the types and prices of the new gear. For a detailed up -to- the -minute buyer's guide, look for the 1966 edition of "STEREO /HI -FI DIRECTORY" on your newsstand. This excellent guide itemizes all the performance specifications, models, and prices -for only $1.25.

Amplifiers. Solid -state amplifiers are being sold this very month in every price category from $59.95 (Knight -Kit KG -320 at 16 watts per channel of music power) to $300 (James B. Lansing SA600 at 40 wpc r.m.s.) . Kits are particularly popular including the integrated Heath AA -21D tagged at $137 for 50 wpc (music power). If you're satisfied with less power, try the Heathkit AA -22 (33 wpc for $99.95) .

Acoustech offers a preamp and power amplifier at $199 and $149, respectively; the power amplifier is rated at 45 wpc. Scott offers the LK -60 with 60 wpc at $189.95.

Budget- priced amplifiers with factory 50 POPULAR ELECTRONICS

Music power output of the Sherwood S -9900 is rated at 45 wpc. Power bandwidth at 1% harmonic distortion is 12 to

' 35,000 cycles. This solid -state amplifier sells for about $230.00.

This small amplifier was designed by Shure Brothers for private headphone listening to records, tapes, or FM tuners. Called the "Solo- Phone" (Model SA -1), the amplifier may also be used as a tape monitor. It sells for only $45.00.

The Electro -Voice 1177 stereo FM receiver stands just 33/8" high. Rated at 25 wpc, it sells for $280.00. A big brother (Model 1178) has AM broadcast coverage in addition to FM /FM multiplexing for $315.00.

wiring include the Lafayette LA -340, putting out 20 wpc for $79.95, Knight's KN -966 with 33 wpc and fetching $119.95, and the high -style Electro -Voice 1144, 25 wpc, for $124.50. For a 35 watts or more per channel amplifier, take a look at Sherwood's S -9000 (75 wpc at $299.50) , Fisher's TX -300 (50 wpc at $280) and the Altec Lansing 360A (35 wpc, tagged at $389) .

Tuners. Although "solid state" has not captured a major share of the tuner market, it is nevertheless making serious inroads on tubes. Actually the difference between tubes and transistors in FM tuners is not as apparent as in amplifiers. Some manufacturers combine the best of tubes and transistors, as ex- emplified by Grommes ( Model 2000 tagged at $249.95) and Kenwood ( Model TK -500 at $174.95) .

Of course, the big problem in selecting a tuner is making a decision about the necessity for AM as well as FM and /or FM /FM multiplex. Tuners run the gamut of prices from the low -cost Eric (Model ST -100 at $99, list) for FM only, to the Scott 312B with FM /FM multiplex pro-

November, 1965

visions at $249.95. Kits are also available, with the Heathkit AJ -43D selling for $109 being a noteworthy example. The AJ -43D has AM /FM /FM multiplex reception. Allied Radio offers a similar setup known as the KG -765, for $94.95 as a kit and $139.95 prewired.

Receivers. Several years ago these units were called "stereo receivers" because they generally consisted of two complete amplifiers, FM tuner, and multiplex adapter. The word "stereo" is being dropped, but the "receivers" still need only to be connected to a phono player and speakers to be a complete stereo hi -fi setup. Of course, transistors have been tremendously important to the receiver manufacturers. Back in the tube days, the stereo receiver threw off heat like a blast furnace and some of the more poorly designed receivers soon cooked themselves to death.

If you're cost -conscious, take a look at the EICO 3566 with 35 -plus wpc sold in kit form for $219.95. Health has the AR -13A kit with 20 wpc (Heath rating) for $184; this Heathkit has a built -in


51

WANT a cheap, effective, and reasonably attractive enclosure for an 8"

speaker? Although the "99¢ Enclosure" grew out of the need for a temporary setup, the unit is quite appropriate for permanent home hi -fi systems, especially where positioning of conventional en- closures for best stereo listening is ham- pered by furniture placement or pecu- liarities of the room's general layout. The portability and durability of this unit makes it practical to store a couple of them out of the way, then move them into position each time they are used.

The speaker used by the author was a Lafayette SK -128, but any other full - range 8" speaker would be equally appropriate for use in this unique enclosure. Construction can be completed in five or ten minutes with the aid of a drawing compass, measuring tape, and penknife.

Construction. The "enclosure" is available, practically ready for use, in almost any department or variety store, in the form of a "Steri- lite" 44 -quart polyethy-

UNIQUE

99G

SPEAKER

ENCLOSURE By JOHN N. AYRES

Simple plastic baffle uses inverted wastebasket

lene wastebasket (U. S. Plastic Company Model #1040) . Prices may vary but the pilot model was obtained at a cost of 99 cents. This container is approximately 20" tall and tapers from a diameter of about 14" at the top to a little over 11" at the bottom. It comes in three colors: beige, turquoise, and yellow. The material is sufficiently soft so that undesirable resonances are avoided, yet firm enough to easily support the heaviest 8" speaker.

The general idea is to place the wastebasket on the floor, upside down, and mount the speaker in the bottom. To prepare the basket, first determine the actual diameter of the speaker cone (it will be about 7 ") , then adjust your drawing compass to half that amount -the radius -and draw a circle on the bottom of the basket. Be sure the pivot of the compass is in the exact center. Now, using a penknife, cut the opening for the speaker following the line as closely as possible, but don't worry about minor irregularities since the edge will not show. Punch the mounting holes using


Turn the wastebasket upside down anc cut out a hole

to pass the frame, but not the rim of the 8 -inch speaker.

Holes in bottom of inverted basket are ports to release

back pressura. Dress the enclosure up with a decorative grille

(shown n right hand photo).

the speaker itself as a template; a paper punch or any sharp, pointed instrument will do the job.

Using the Enclosure. Connect the speaker leads to your amplifier, and sit back and listen to a familiar record. You will find the upward firing arrangement quite desirable, for the sound spreads out in all directions- obscuring the fact that you are listening to a small 8" speaker. Use of a pair of them imparts an amazing stereo effect, totally elimi- nating any "hole -in- the -middle."

A decided improvement in bass response will be observed if the enclosure is supported about two inches above the floor. But instead of rigging up an elab- orate support, the same effect can be had by cutting six or eight equally spaced 2" holes around the circumfer- ence of what now serves as the bottom of the enclosure ( originally the top of the basket). Keep the holes as close to the bottom as possible, using a tape measure and drawing compass for layout and a penknife for cutting as before.

This time, however, take pains to make your cuts as clean as possible, since they will not benefit from concealment as does the big opening for the speaker. Very fine sandpaper can be used to smooth off the edges.

You can also install a suitable protective and decorative cover for the speaker if you are willing to exceed your 99yß,

budget. Radio stores have grilles for wall or ceiling installations that will do nicely However, be sure the one you select has an overall diameter not exceeding 1O' ", so that it will fit the basket properly. (Electro- Products' #SG -8CO3 among others, makes a good fit and is attractive as well). Four pan - head machine screws, washers, and nuts secure the works.

Bearing testimony to the value of the finished product as both a unique, attractive conversation piece and an acousti- cal dev.ce of commendable performance, the author's dentist extracted his two SK -128 speakers from their factory en- closures and put them into a pair of the 990 wastebaskets. --

November, 1965 53

WE KNOW YOU'RE THERE . . . BUT WHERE OH WHERE? A literal antiworld populated by stars and planets and made up of atoms of antimatter may well exist physically in addition to the known material universe, according to Dr. Leon Lederman, professor of physics at Colum- bia University. Dr. Lederman presented new basic evidence for the possible ex- istence of such an "antiworld" in reporting with his associates on the discovery of a new elementary particle, the "antideuteron." The new particle is the antimatter counterpart to the nucleus of deuterium, or heavy hydrogen. In demonstrating its ex- istence, the Columbia research team used the 33- billion electron -volt synchrotron at the Brookhaven National Laboratory.

The antideuteron is the first compound of antiparticles ever observed, and consists of an antiproton and antineutron," Dr. Lederman explained. Knowing that the antideuteron exists means that all the properties of the nuclear force responsible for the stability of all nuclei "are closely mir- rored in the antiworld." As a result, he further stated that "It is no longer possible to question the basic physics part of the cosmological conception of a literal antiworld made up of negative nuclei surround- ed by positive electrons. It is not possible now to disprove the grand speculation that the antiworld could be populated by thinking creatures."

The evidence would seem to indicate that this antiworld does not only have antiparticles replacing particles, but also is a

mirror image of our world, in which the flow of time is also reversed. Just where this antiworld is, though, is somewhat of a

mystery. Investigators have looked, without success, for evidence that it interpene- trates the known physical universe. Dr. Lederman pointed out, however, that "in cosmological theory, if the whole thing started with an explosion, there is every reason to believe that the same number of particles and antiparticles were created."

LITTLE THINGS MEAN A LOT -Two large -scale computer memory systems able to store more than a

trillion bits of digital information will be built for the Atomic Energy Commission by International Business Machines Corporation. Basic storage elements are film chips contained in plastic cells; the tiny cell held by Melva Ellis of IBM can store the equivalent of three encyclopedia volumes -about 4.5 million words. Data will be recorded by means of an electron beam which "writes" digital data on the film chips in the form of microscopic black and white coded spots. When information must be retrieved from, or stored in, the memory systems, the cells move automatically to photoelectric reading and writing stations. Retrieved data can be printed, recorded on magnetic tape, or viewed at remote data display devices. To be installed by IBM in 1967 at the Lawrence Radiation Laboratory in California, the mass memories will be used to store results of experiments processed by the laboratory's vast computer complexes.


ELECTRONIC WHEELCHAIR DEVEL- OPED-A hat -mounted electronic control system which enables people whose limbs are paralyzed or amputated to operate wheelchairs and other equipment by head movements was recently described by its inventor, Donald Sel- wyn, a systems analyst at International Telephone & Telegraph Corporation. The equipment permits a quadriplegic with normal head mobility to drive himself about in a motorized wheelchair. According to Selwyn, the system also has military and commercial applications, as it will permit a normal individual to perform complex tasks otherwise requiring an extra pair of hands.

Before being provided with a servo - controlled wheelchair, Bruce Lowe, a

quadriplegic at New York's Goldwater Hospital, depended for nearly 10 years on the assistance of hospital personnel for wheelchair transportation. Now, however, he propels himself around without any assistance and is studying pre -law at Long Island Uni- versity. He has maintained an A average and has won a scholarship.

Bruce's wheelchair is equipped with a head -controlled tape recorder for taking and reviewing spoken notes at the college. By simply nodding his head he can perform all maneuvers required for parking and navigating around obstacles. Special nodding se- quences can selectively operate the tape recorder or other devices.

"OLD- FASHIONED" METAL SCORES COMEBACK - A pea -size pellet, traveling at meteoroid speeds, wrecked these sheets of aluminum during tests made by Boeing Company engineers in Seattle. The purpose of the tests was to find the best metal to use in building manned spacecraft. Despite the damage shown here, test results favored use of the "saucepan" material over space -age metals.

GEMINI 7 TO USE LASER TRANSMITTER -NASA has scheduled a communications test between the two -man "Gemini 7" spacecraft and the earth using a laser device built by Radio Corporation of America. One of the astronauts in the spacecraft will aim the laser transmitter at another laser light beamed at the spacecraft from the White Sands Missile Range in New Mexico during the 14 -day flight set for early 1966. When the light -beam receiver picks up the pulses of light from the spacecraft, the ground laser beacon will flash to indicate contact made. Weighing only six pounds, the device puts out 16 watts.

November, 1965

ORBITING OBSERVATORY UNDERGOES TESTS -Electronic equipment for an orbiting observatory that will help scientists determine the origin of stars is being tested by Sylvania Electric Products, Inc. Here, an engineer is seen checking equipment inside a thermal- vacuum chamber where temperatures range from 70 °F below zero to 160°F. The equipment includes data processing and programming devices, a guidance system, and a power supply. The observatory, to be carried aboard the largest unmanned satellite under development by NASA, will permit scientists to measure the light absorption characteristics of interstellar gas and dust clouds, from which, it is believed, stars are formed. Until now, astronomers have been unable to study this light because it is absorbed by the earth's atmosphere. The space vehicle will be launched with a circular orbit 500 miles above the earth sometime in 1967.

55

THE HAM

AS

SEEN

BY

WALT MILLER

t4`{ xi

°

"WA6OXX mobile, this is WA6ZRG mobile. You've got an extremely strong signal. What's your QTH ?"

"William Able 6 Oboe Zebra Zebra? I pictured you quite differently!"

vn

"Will it bother you if I vacuum in here ?" "Oh, forget it. I can get a new suit any time."


By LOUIS E. GARNER. JR. SUPER -SENS

Versatile electronic relay provides tcnlimited control haletions

DO YOU need a burglar alarm, a fire alarm, an automatic fan control, an

automatic light switch, a liquid level control, an automatic dehumidifier control, a photoelectric counter, a radio remote control, a lawn sprinkler control, an automatic door opener, a time delay relay, an electronic latching relay, or a sound -actuated relay?

Would you like to amaze your friends and neighbors, gain the respect of your teachers or co- workers, assemble a Science Fair project that is different, or build a basic control that can be used in hundreds of applications?

If you can answer yes to any of these questions, you'll enjoy building and using Super -Sens, an easy -to -wire, inexpensive electronic relay so sensitive that it can be tripped by a pencil line drawn on a piece of paper.

Electronic relays are not new. They have been designed and manufactured for years. You can purchase a variety of types at prices ranging from $20 to S50 or more, or you can build Super - Sens for less than $10.00.

One popular "supersensitive" electronic relay offered by a leading laboratory supply house requires a signal current

of 50 microamperes at a little under 10 volts. Super -Sens, in contrast, will trip with a miniscule control current of about 0.2 ita. at approximately 1 volt. Using its built -in bias circuitry, the device can trip with as much as 50 megohms between its input terminals.

Super -Sens can be actuated by many input devices: photocells, humidity detectors, microswitches, thermostats, magnetic contacts, pressure switches, thermistors, and almost any high or low resistance type of sensor or probe, as well as the comparatively low level signals obtained from a carbon microphone or a simple radio receiver.

Super -Sens, in turn, can be used to actuate almost any type of electrically operated equipment : lamps, solenoid valves, buzzers, bells, power relays, fan motors, pumps, door openers, heating systems, etc.

HOW IT WORKS

Super -Sens is essentially a two -transistor, high -gain, direct -coupled d.c. amplifier driving a standard sensitive - type electromagnetic relay. See Fig. 1. Transistors Q1 and Q2 are connected in a modified Darlington circuit. (A Dar-

November, 1965 57

B 0K R2

Fig. 1. As little as 0.2 µa. at i volt is enough to trigger relay; up to 50 megohms can be sensed.

N.C.

ARM

lington circuit is a circuit having two or more transistors connected in such a manner as to have a single input, a common load and a current gain which is the product of the current gain of each transistor.)

Series resistor RI tends to limit base current to prevent accidental damage to the transistors by excessively strong in-

I

SENSOR D.C. VOLTAGE

OUTPUT

s S

G

SUPER SENS

® B

put signals. Unbypassed emitter resistor R3 stabilizes c ircuit operation, and provides a degree of temperature com- pensation. Sensitivity control R) and current limiting resistor R2 are parts of a bias and control circuit to permit the use of external resistile -type and switch - type sensors. Circuit power is supplied by BI and is turned on and off with s.p.s.t. switch Si.

When a signal or bias voltage of proper polarity (base positive with respect to emitter) is applied to the base emitter circuits of QI and Q2, the transistors conduct and energize Kl. Bias voltage can be taken from the internal R2, R4, B1 circuit (B terminal) or it can be derived from an external circuit.

There are essentially three basic types of input circuit control devices that Super -Sens will cater to: those that look like a voltage source, those that look like a resistor, and those that look like a switch. The voltage source devices are hooked up to I and G.

The resistor control types are given special consideration: high- resistance devices are connected across terminals I and B (in series with the internal

SENSOR HIGH

RESISTANCE

Fig. 2. Any one of three basic types of sensors can be used: those that look like a voltage such as a photovoltaic cell, etc.; those that look like high or low resistors; and those that act like a switch.

LOAD

EXT. POWER SOURCE

N.0

ARM

N.O.

SUPER- SENS

LOAD

EXT. POWER SOURCE

Fig. 3. Controlled external load circuit can utilize almost any source of power. If power requirements exceed the relay contact's rating, a power relay can be added. One or two loads can be switched.

N.C.

ARM

N.O.

SUPER - SENS

LOAD A

TO EXT POWER SOURCE

LOAD B


Fig. 4. Etched circuit board construction provides a mounting base for all the components, including the relay. Conven- tional chassis -type construction is also quite suitable. If you want to make your own printed circuit board, you can use these actual size photos as guides. All components are mounted on one side of the board (top). The foil side (bottom) must be clean to prevent leakage between conductors.

bias circuit) and low- resistance types are placed between terminals / and G with a jumper from terminals I and B, as shown in Fig. 2. Actually, the re- sistive devices are made to function like a voltage source, since terminal B has sufficient voltage of proper polarity to forward -bias the transistors.

Switch -type devices can be connected between points I and B, and R.t adjusted to provide just enough voltage to pull in the circuit when the switch is closed. Conversely, these switches can also be made to drop out the circuit. A jumper between I and B, and R4 adjusted to pull in the circuit, will keep the circuit on until a switch across I and G causes the circuit to drop out when it is closed.

The relay can be hooked up to provide either a normally open, or normally closed control circuit, or both, as shown in Fig. 3.

CONSTRUCTION

Since the basic unit is the same for all applications, let's put the thing together, and then we'll consider some of the many applications. All components are standard and readily available through most electronics supply houses.

PARTS LIST BI- 6-1' voll helleer lil Relay (1.I1((1 (,.1 -100 or equivalent) Q1, Q2 -i'1416 lran.sist or R1 1000 -ohm. '2-watt resistor R?-- 10.000 -ohm. .aalt re.rr.rlor 113- -47 -ohm. '_ -.ault resistor RJ 1- nregohrn potent /owe er, linear -tapir

tootle or slide zt, i/r h

1- Ehear eirrnit hoard'' I Cab/net i .11 inibo.t 210' Misc.-Small knot). se ret,'s, nuts, ha rls,'ors. girr.

solder. rte.

*.A pre -etched circuit Imard sin an epoxy -class base is available from I)I('O. Box 160411. San -Antonio. Texas 75216 for 51.00. This firm can also supply: a "basic" kit l board. relay. Iran -

sistorsl for S7.50: a complete kit for 59.50: and a pre -etched moisture sensor for 51.50.

If you etch your own board, follow the actual size layout shown in Fig. 4. Wiring is not critical, but special pre- cautions should be taken. First, be sure there is ample separation between the I, B, and G terminals. Second, use an epoxy -glass rather than a paperbase phenolic copper -clad base board, (moisture absorption in the latter material may cause erratic operation) . Third, be sure to remove all of the unused copper during the etching process, for an al-

November, 1965 59

NIGHT

52 53

TEST d

F2

F3

F4

SUPER - SENS

G

B BATT +. -

°1ARM BELL

SI POWER

Fig. 5. Fire alarm circuit has fusible links Fl to F4, and thermostatic contacts Tl, T2. Door and window contacts Cl to C3 and foil patterns make up burglar alarm. Place sensors in strategic locations.

most invisible, microscopically thin layer of copper can provide sufficient conduc- tion to actuate the relay.

To avoid accidental mechanical damage, mount the relay last. Heat - sink the transistor leads with a pair of long -nose pliers to prevent heat damage when soldering. The Sensitivity control can be mounted on either side of the board.

The completed board can be mounted in a small Minibox as a self- contained instrument, or in another piece of equipment, depending on the device's ultimate use. Mount the board on spacers to provide air space between the board and the cabinet. Power supply B1 can be built in or externally connected.

A number of component changes can be made to meet individual needs. Gen- eral Electric GE -10 transistors will

CI

.25Ní.

R

20MI EG.

G

B

SUPER. SENS

serve as direct replacements for the specified T1 units. A Sigma 4F- 1000 /S- SIL relay can be used in place of the JAICO type, although a new layout and larger circuit board would be required. If maximum sensitivity is needed at all times, omit R4 and connect R2 directly to the S1, K1 junction.

A variety of power supplies can be employed. The total current drain when the relay is closed is only a few milli- amperes, permitting the use of small transistor -type batteries.

As might be expected, the instrument's ultimate sensitivity depends on supply voltage, component tolerance, and the gain of the transistors. With the components specified in the Parts List, the current sensitivity (for relay closure) will vary between 0.15 and 0.45 µa., using a 9 -volt power supply.

Ci

30yf. (A) (8) (C)

OFF ON

2yf.

R O MI EG.

G

((

SUPER - SENS

Fig. 6. An RC network can be added to make a time -delay relay. Circuits (A) and (B) stay on for a desired time after the switch is opened. "Turn on" is delayed in circuit (C) when the switch is closed.


If higher gain transistors are used, the overall sensitivity may be as great as 0.1 (or less) µa., while lower gain units may provide a sensitivity of 0.75 1I.a.

APPLICATIONS

Burglar and Fire Alarm. An easily installed alarm system, suitable for a home or place of business, is shown in Fig. 5. It offers fire alarm protection during the day, and both fire and burglar alarm protection at night.

A break in any part of the external series circuit will trigger the alarm. A "push -to- test" switch (S3) , when de- pressed, will sound the alarm if the relay circuit is in working order.

Fire protection is afforded by fusible links Fl to F4 and by thermostatic contacts Ti and T2 placed on ceilings in strategic locations. Door and window contacts Cl to C3, together with the foil patterns, provide burglar protection. Any combination of switches, contacts, or links can be used, so long as the circuit forms a closed loop and the total resistance of the loop isn't great enough to prevent an adequate amount of voltage from terminal B to be applied to terminal I. The sensitivity control can be adjusted to compensate for loop resistance and battery conditions.

Switch S2 skips the door and window detectors during the day, and Si, which can be lock -protected, serves as a master on /off control. If switching S2 from night to day or day to night causes a momentary but undesirable alarm, connect the Night side of the switch to the switch's center arm. In this mode of operation, Super -Sens is on all the time, the relay is energized, and the normally closed contacts are held open.

Occasionally, a latch or alarm -hold type of operation is desirable . . . that is, once the alarm is triggered, it sounds continuously even after a break in the loop is restored. In this type of operation, the alarm can be reset only at the main panel, which could be located inside a locked cabinet. To build in the latch feature, connect a 1- megohm, ! -watt resistor in series with terminal I and S2. Adjust the Sensitivity control until the relay just pulls in ( silencing the alarm) ,

then back off slightly. Use the test switch and control alternately, and adjust until the desired action is achieved.

November, 1965

Time Delay Relays. Controls which can switch a circuit "ON" or "OFF" for pre- set or adjustable periods of time are used extensively in experimental work, photography, laboratory tests, chemical processing and manufacturing. Super - Sens can be used in such applications by adding a relatively simple "time delay" accessory. Typical circuit arrangements are shown in Fig. 6.

A 20- megohm resistor connected in series with a 0.25 -µf. capacitor in Fig. 6 (A) sets up a time delay on the order of 3 to 9 seconds, depending on the setting of the Sensitivity control. A momentary normally open contact switch connected across the capacitor allows the circuit to conduct when the switch is pressed and released. The relay closes and remains closed until Cl is charged up and stops drawing current.

The circuit in Fig. 6 (B) permits a wider range of control. When SI is de-

SHORT LENGTH OF CO -AX

TO SHIELD B

SUPER- SENS

CLAMP

INSULATED BUSHING

(A)

--TANK

METAL TANK

SUPER- SENS

(B)

Fig. 7. Levels of low- and high -conductive liquids can be monitored by easily made probes.

61

SUPER -SENS

-N B

MOISTURE (A)

MOISTURE SENSOR

Fig. 8. These circuits can be used to control humidifiers and lawn sprinklers. Just a drop of rain on the sensor will release the relay in circuit (A). Circuit (B) can detect slightest trace of moisture.

pressed and released, Cl is charged by the bias supply and then discharges slowly through the instrument's input circuit, holding the relay closed until Cl loses most of its charge. The time delay varies with Rl's setting, and ranges from about 25 seconds with Rl set at 0 resistance to as much as 1 minute and 45 seconds when Rl is set at 1 megohm. The timing range can be changed if you use different values for Cl and Rl. The larger the time constant (R1 x CI), the longer the time delay.

In Fig. 6 (C) , a delay in "turn on" time takes place after the slide switch is thrown. When SI is switched to the "ON" position, the relay does not close until the current through Rl and Cl falls off enough to reduce the voltage drop across Rl.

Liquid Level Control. Farmers, chemical engineers, food processors, electroplat- ers, beverage manufacturers, industrial plant operators and others need to check or maintain liquid levels in large tanks or vats from time to time. Super -Sens can do an excellent job in such applications when used with suitable sensor probes. Typical techniques are shown in Fig. 7.

A short length of rigid coaxial cable can be used as a simple liquid sensor probe if clamped to the side of a tank. If the cable's shield is connected to the instrument's B terminal and the center conductor to the I terminal, the relay will close when the liquid reaches the exposed lower end of the cable. Connec- tions are as shown in Fig. 7 (A) .

If a metal tank is used, the sensor probe may be a short length of conductor mounted in an insulated, liquid -tight bushing at an appropriate point on the side of the tank, as illustrated in Fig.

7 (B) . If the liquid is highly conductive, connections can be made to the I and G terminals, with a jumper between the I and B terminals. With these connections, the Sensitivity control is adjusted until the relay just closes. The relay will open when the liquid level reaches the probe.

Other types of probes can be used, of course, including insulated metal strips cemented inside the tank or short parallel metal rods mounted on an insulating block and attached to the tank. Regard- less of the probe used or the type of liquid handled, Super -Sens can control pumps or solenoid valves, or activate remote signaling devices.

Rain Alarm. A standard moisture sensor plate will make Super -Sens serve as a rain alarm. The sensor plate leads are connected as shown in Fig. 8 (A) and operate in the same way as the level control in Fig. 7 (B) . Just a drop or two of rain on the sensor plate is enough to cause the relay to open.

Humidity Control. A modification of the "rain alarm" circuit is shown in Fig. 8 (B) . Here, the moisture sensor plate is connected and operated in the same manner as the circuit shown in Fig. 7 (A) . With this arrangement, Super - Sens' high sensitivity will respond to the slightest trace of moisture and close the relay. It can detect the small amount of moisture condensed from a person's breath and can be used, among other applications, for controlling a dehumidifier.

Lawn Sprinkler Control. If the moisture sensor plate used in the "rain alarm" and "humidity control" circuits is replaced by a pair of semi -insulated spike - type probes driven into the ground, Su- per -Sens will serve as an automatic lawn sprinkler control. Its output terminals



IF ONE ANTENNA is good, why aren't two better? They are. Two properly

stacked antennas will bring in about one -and -a -half times more signal voltage than a single antenna; a stack of four can almost double the signal voltage. Of course you can't just keep doubling the antennas indefinitely. Beyond eight, there is no appreciable increase in signal pickup.

However, increasing signal strength isn't the only reason for stacking antennas. In fact, it isn't even the best reason. If you need more signal pickup, you may be better off buying a more expensive, higher gain antenna than stacking two antennas. And, if even the best antenna you can find doesn't do the job, you should probably add a good mast- mount- ed preamplifier.

When should you stack antennas? When you are faced with certain reception problems that can't be solved in any other way. There are two ways to stack antennas: vertically and horizontally.

Vertical Stacking. There are three reasons for stacking antennas vertically:

(1) To reduce signal fading from distant TV stations;

HOW TO

STACK

TV ANTENNAS

TO

INCREASE

SIGNAL

STRENGTH

AND TO

REDUCE GHOSTS

By LON CANTOR Jerrold Electronics Corp.

VERTICAL STACKING reduces fading

reduces airplane flutter increases signal pickup

HORIZONTAL STACKING reduces ghosts

reduces man -made interference reduces adjacent -channel

interference reduces co- channel

interference increases signal pickup

(2) To reduce airplane flutter; (3) To increase signal pickup. Because TV signals are so high in fre-

quency, they are limited primarily to line -of -sight distances. However, by various means, they do manage to get to "blind" areas and regions a short distance over the horizon. While lower frequency radio waves do follow the curva- ture of the earth and TV signals don't bend very well, a small portion of the TV signal does bend around obstructions to get to the antenna. This can take the form of a knife -edge type of dif- fraction as from the roof -edge of a building, or a gentler slope as from the top of a hill.

Television signals also reach the fringe antenna by reflection -bouncing off of atmospheric interfaces, and refraction - bending caused by atmospheric layers with different densities.

Let's suppose you're putting up a fringe antenna. You won't get the most signal just by mounting the antenna as high as possible. Instead, you must carefully probe for the height that gives you the best possible TV pictures. Because of the methods of signal propagation, this height is quite critical. It is the height at which most of the diffracted, reflected, and refracted signals that are present arrive in phase. At heights at which these various signals arrive out of phase, they actually subtract from each other.

The trouble is that the signals that reach the antenna by atmospheric reflection and refraction are not stable. They change as the atmosphere shifts. This is the main reason for signal fading in fringe areas.

The solution to this problem is the vertical stack. You put the two antennas at different heights. Thus, when one

antenna is receiving out -of -phase signals. the other is receiving in -phase signals. If you combine these two antennas properly, you wind up with an average signal that doesn't vary much. This is a form of diversity reception.

When the antennas are not delivering the same signal, the out -of -phase antenna acts as a load to the in -phase antenna. Instead of getting additional signal, you actually get less than the in -phase antenna alone can deliver, unless you effectively isolate one antenna from the other.

TWINLEAD TRANSFORMER

1 COAX HYBRID

SPLITTER

MATCHING TRANSFORMER

TWINLEAD

TO TV SE T

Fig. 1. Hybrid splitter allows signals from each antenna to add to each other, and minimizes loss when one antenna acts as a load on the other. Leads to transformers and splitter should be equal.

Commercially available stacking bars won't do the job. Stacking bars are fine when both antennas are delivering approximately the same signal. Obviously, this is seldom the case in a fringe installation.

Figure 1 shows how antennas should be vertically stacked to minimize signal fading.

There are five important things to do to make a good vertical stack.

(1) Use identical antennas. (2) If you use coaxial cable, such as

RG -59/U, you should also use a weather- proof 300 -ohm to 75 -ohm matching trans-


CHANNEL NUMBER

FREQUENCY WAVELENGTH RANGE (mc.) (inches)

2 54-60 205 3 60 -66 186 4 66-72 170 5 76-82 148 6 82 -88 138 7 174 -180 66.5 8 180 -186 64.5 9 186 -192 62.25

10 192 -198 60.5 11 198 -204 58.5 12 204 -210 57 13 210 -216 55.25

Fig. 2. Select wavelength of lowest channel to adjust space between stacked antennas to prevent mutual interference. Two- thirds wavelength is minimum.

former mounted as close as possible to each antenna.

(3) Use a hybrid type splitter. This type of unit is like a one -way valve. The output contains the sum of the two inputs, with virtually no loss. Yet the two inputs are isolated from each other. Even if the signal on one antenna goes down to zero, it cannot subtract more than about 10% of the signal from the other antenna.

(4) Space the antennas at least two - thirds of a wavelength away from each other on the mast. A full wavelength is preferred, but this is not always possible. In calculating this distance, use the wavelength of the lowest channel in your area. Figure 2 shows the wavelengths of all the VHF channels.

(5) Make the harness symmetrical. The lead run between each antenna and its matching transformer must be identical. Similarly, you must use equal lengths of cable between each matching transformer and the hybrid splitter.

Horizontal Stacking. It is foolish to use a horizontal stack simply to increase signal pickup. It is easier, cheaper, and just as effective to use a vertical stack for this purpose. Horizontal stacks, however, may be the only possible way to do the following things:

(1) To reject ghosts; (2) To minimize co- channel interfer-

ence; (3) To minimize adjacent -channel in-

terference; (4) To reduce man -made interference. Figure 3 shows the reception pattern

of one log- periodic antenna, compared

November, 1965

with that of two of them horizontally stacked. Notice that stacking not only increased gain, but changed the pattern considerably. The stacked pattern shows two side lobes, although there are others, with nulls in between. These nulls are important. You can use them to get rid of unwanted signals.

The pattern shown in Fig. 3 is for one particular horizontal stacking situation: when the antennas are stacked precisely one wavelength apart (center to center) .

Notice that under these conditions nulls

o

Fig. 3. Angle of null points can be changed by adjusting the spacing between horizontally stacked antennas (solid line) to drop out interference. Dotted line is response curve of single antenna.

are produced at 30° to the right and left of 0 °.

Now, suppose you had a tall tower re- flecting a ghost signal from an angle 30° away from the transmitted signal. You would simply aim the two antennas at the transmitter, the ghost would conveniently fall into the null, and you'd never see it on the TV screen. It is seldom, however, that you can count on unwanted signals coming in from precisely one of those angles. Therefore, you have to find a method of varying the angles of the nulls.


65

PROTECT

YOUR CAR'S

ELECTRICAL SYSTEM

By CHARLES ERWIN COHN

Forty -five -cent link provides under -the -hood fire protection

M OST VEHICLE lighting and electrical accessory circuits are well -

protected by fuses or circuit breakers. However, the main feedline which con- nects the battery to the generator and to all circuits, except the starter, and the circuit wiring up to the fuse block or circuit breaker very often go unpro- tected. Should a short occur at a point ahead of the protective devices, the high currents would cause extensive wire damage, battery damage, and possible fire.

At a cost of only 45 cents, it is now possible to minimize this hazard. A fusible link introduced by Chrysler Corpora- tion on its 1965 autos can be adapted for use in any car equipped with a 12- volt battery system. The part number is 2580389, and it can be obtained from any Chrysler dealer.

The link is a short length of 16 -gauge wire which behaves like a fuse. Because the regular wiring in the car is much

FUSIBLE LINK

12V

T

FEED LINE

STARTER SOLENOID

TO STARTER

Insert fusible link between battery and main electrical feedline. Should the link fail for any reason, you can reconnect the main feedline as before.

heavier, the link will burn out before the regular wiring has a chance to do extensive damage in the event of a short. At 30 or so amperes, the link runs hot; and at about 40 amperes, it quickly melts. Normal total current requirements in a car rarely exceed 30 amperes. For the system to operate again, once the link fuses, it must be replaced. Special heat - resistant insulation is used to safely contain the hot link.

As shown in the diagram, the link is connected as close to the battery in the electrical system as possible. It should not be inserted in the starter circuit. Usually, the link can be attached to the "hot" terminal of the starter relay. As a safety precaution, disconnect the battery before you install it, and reconnect the battery after the job is done.

Disconnect the feedline from the solenoid, and connect the end of the link with the larger terminal lug to the solenoid and the other end to the feedline. A small nut and bolt can be used to connect both wires. All connections should be firm. The junction of the link and the feedline should be taped, and positioned so that it will not accidentally cause a short circuit.

In the event the link gives way when you are miles away from a service station, reconnect the feedline as it was originally -after you have cleared the short circuit.


ELECTRONIC MATH QUIZ By ROBERT P. BALIN

Many basic electronic circuits can and do perform mathematical operations ranging from elementary arithmetic to integral calculus. See if you can identify the electronic circuits (A -J) below which perform the mathematical operations (1-10) at right.

(Answers on page 115 )

A

O WWW. o

TZ o T a

f

J L

D

M

I Add

2 Count

3 Differentiate

4 Double

5 Divide

7

10

November, 1965 67

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Train for radio sales and service with dealer distributor.

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(INCLUDING COLOR) Covers installation, adjustment, repair and servicing of black and white and color television ... prepares you for your own sales and service business.

6 STEREO, HI -FI AND SOUND SYSTEMS A growing field. Prepares you to build, install and service modern sound equipment for home or industry.

7 BASIC ELECTRONICS

Gives you the fundamentals you must know to build on for a future Electronics career. Also offers an excellent background for Salesmen, Purchasing Agents, and others in Electronics.

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PREDICTED RADIO RECEIVING CONDITIONS EXCELLENT DX IS PREDICTED FROM NOVEMBER THROUGH FEBRUARY

By STANLEY LEINWOLLE Radio Propagation Editor

THE WINTER of 1965 -66 is likely to be the last good DX'ing winter season for

the AM broadcast band for some years. As the sunspot numbers increase, we can expect to see more medium -wave signal absorption in the ionosphere. Propagation of medium -wave broadcasting signals over great distances is dependent on many fac- tors, including transmitter power, frequency, antenna characteristics, latitude of the transmitting station, sunspot activity, the time of day and, of course, the season of the year.

During the winter nighttime listening periods, when noise levels in the Northern Hemisphere will be at a minimum, DX conditions should be at their very best. The graph on this page shows the signal strength variation in DX reception versus local time at the mid -point of the path between transmitter and receiver. For European AM broadcasting stations between 500 -1600 kc., the best DX period should be from approximately 2100 to 0000 EST.

The following is a summary of DX receiving conditions expected during the period from November, 1965, through Feb- ruary, 1966.

41 and 49 Meters. Continuing the trend of the past several years, these bands will

10

o

J 10

m U

be best for DX reception during the evening hours. Among the stronger stations heard in this hemisphere will be West Germany on 6075 kc., and the BBC on 6195 kc. Not easy to log, but worth looking for, will be Italy on 6060 kc., East Germany on 6115 kc., and RIAS on 6005 kc. The latter station operates 24 hours a day from West Berlin with transmissions aimed toward East Germany.

The BBC will be active on 7130 kc. with transmissions beamed to the South Pacific* but coincidentally passing over the East Coast of North America. The Russians will be found throughout the 40 -meter ham band with transmissions beamed to North America, particularly their block- buster signal on 7150 kc.

31 Meters. DX receiving conditions in this band will improve during the early winter months. Expect to hear DX stations starting from late afternoon local time. Re- ception will consist primarily of Europeans and Africans, as well as some stations in South and Central America.

Guinea will be on 9650 kc. until 1900 (Continued on page 123)

*See "Shoot a Radio Wave Into the Air," Lein- woll, POPULAR ELECTRONICS, Februarei, 1965, p. 65.

0 z

20

ó J J a ú 30

40

-50 1600 1800 2000 2200 2400 0200

LOCAL TIME AT PATH MIDPOINT

72

0400 0600

This graph, copied from CCIR Report 264, Geneva, 1964, shows the expected signal loss of AM broadcast -band signals vs. time at the mid -point of the signal path. Across the North Atlantic, AM signals should be strongest between 9 p.m. and midnight, Eastern Standard Time. Strength of the AM signal drops off rapidly after about 1 a.m. EST.

POPULAR ELECTRONICS

By CHARLES E. FENOGLIO

SOLID -STATE

FOR 10 BUCKS All -purpose push -pull audio amplifier operates on wide range of input voltage and output impedance without bias adjustments

IF YOU would like to have a quality, low -cost amplifier for a hi -fi or public

address system -one you can use at home or in your car, and can convert into a speech amplifier, modulator, or high -power intercom -then try your hand at this transistorized "Six -Watter." You can build it in less than two hours, at a cost of about $10.00. All components can be mounted on a printed circuit board, and construction is easy.

Several novel circuit features make it possible to use few parts, eliminate transformers, and achieve high efficiency. A unique d.c. bias stabilizing network eliminates the bias adjustments normally found on this type of amplifier and permits operation with a wide range of supply voltages without modification.

The excellent low- frequency response of the Six -Watter is due in part to the absence of transformers and the use of high -value coupling capacitors as well as direct coupling. High -efficiency Class B operation makes it ideal for use wherever battery life is an important consideration. Power consumption from a 12 -volt battery under no- signal conditions is less than 1,4 watt.

While the amplifier can work on any November, 1965

supply voltage ranging from 3 to 15 volts, the higher the voltage source, the greater the audio power output you can get. An input signal of less than 0.2 volt is sufficient to drive the Six -Watter to full output. This is more than adequate gain for most tuners, and crystal or ceramic phono cartridges.

How It Works. Audio input is coupled to the base of transistor Q1 through capacitor Cl. The amplified signal at Q1's collector is direct -coupled to the base of Q2. Here again, the signal is amplified and directly coupled to Q3 and Q4. Transistors Q3 and Q4 work in opposite directions ; while one is conducting more, the other is conducting less -their output signals are 180° out of phase with each other. This type of circuit makes it possible to drive a push -pull output stage without the aid of a transformer.

The signals from Q3 and Q4 are directly coupled to Q5 and Q6 respectively. Transistors Q5 and Q6 operate as Class B power amplifiers. Balanced operation requires that the product of the current gain of Q3 and Q5 be equal to that of Q4 and Q6.

The filter network, C2 and R4, prevents audio voltage variations at point

73

>{R7 Y. .4R8* +

C3

.

L

2AMP

RI 39K RK

2N01305

39K

TUNER

01 2N1694

05

4E

R4 R5 1K

C2 100pf.

R7 4711

IN2069

VOLUME CONTROL IMEG.

TO AMPLIFIER INPUT

(SEE TEXT)

R6 68011

04

06 R8 2N554 C3

4711 1000pf.

2N1305

3 TO 15 V

SPKR 3.211

41

_j = Fig. 1. The audio amplifier uses a novel six -transistor circuit requiring neither transformers nor bias adjustments. It operates with supply voltages of between 3 and 15 volts. An input signal of 0.2 volt is sufficient to drive it to full output. Volume control can be added if desired.

PARTS LIST ('1- 1V -µf., 15 -voll electrolytic capacitor C2- 1(1(1 -µf., 15 -volt electrolytic capacitor C'3- -1ni0 -17i.. 15 -volt electrolytic capacitor D1-1 X2065 diode I,1- -2- ampere fuse (11 2-V1hU -1 ransistor O3. (14 2.V130í transistor O3- 2.V 130-1 Irausislor (15. Oh 2.V55 -1 or 2.V21 -lS transistor R1, R2 30,11(10 -ohnt, 15- 1.5111 resistor R.î. I. R5 111110 -ulun 1 -watt resistor R6-- 6.1'U- o/l67. 1 _, -1801 t resistor R7. RS -G -oh in. 1-- wt7all resistor 1 Printed circuit hoard, available from Hazlet on

.Scientinc Co., Box 163, Hazel lark, Miei,. -LSU.ï( for $2.55 postpaid with all holes drilled and for 51.55 post paid ondrilled

'- 11." c ' c III" heat sinks, copper or aluminum

A in Fig. 1 from reaching Qi's emitter. This results in a high degree of d.c. stability without affecting the a.c. gain of the amplifier.

Any speaker impedance ranging from 1.6 to 16 ohms can be used. Because power output is a function of speaker impedance, and source voltage, stick to a 3.2 -ohm speaker and a 12 -volt source, if possible.

Construction. You can make your own

o{ DI 1>-. .4 R5 Y.

'4 R6 }-0

R3 )-0

o{ RI Y.

si R2 Y.

S.W° 21 13

b

41

Fig. 2. Carefully locate and solder all of the corn- circuit board, or purchase one for $2.85 ponents onto the printed circuit board as shown.


Fig. 3. Use this full-size guide in making your printed circuit board. Space the transistors about 1 /2" above

the board and hold transistor leads on top side of board with a pair of long-nose pliers when soldering.

(see Parts List) , or you can mount and wire the components on a small (approximately 4" x 6 ") conventional type chassis. If you use the board, locate and solder the parts in place as shown in Fig. 2. Space the transistors about 1(2"

above the board and hold the transistor lead on the top side of the board with a pair of long -nose pliers while soldering.

Heat sinks for Q5 and Q6 can be cut from a v16" copper or aluminum sheet,

HEAT SINK

-1- 4,_ 5/16"

1

17/32' _

T/18' ----- -. I-3/8"

I/8"DIA 27/13e.

p 3 D Á I 5/6'

r-31/32-1-5/32..-.13/8"-- 2-1/2°

f I

/ TRANSISTOR

M ,r/ 6- 32'SCREW

HEAT SINK

CPC BOARD NO.6 NUT

Fig. 4. Use thin copper or aluminum stock to make heat sinks and mount with the transistor as shown.

and should measure 1'ßx" x 21 s ". Drill holes as shown in Fig. 3. Two holes are used to mount each heat sink on the board, and two are used for the transistor pins. Paint the heat sinks black to increase thermal dissipation. If you plan to use the amplifier continuously at high power levels and high ambient temperatures, increase the size of the heat sinks.

Final Check. After completing construction, feed a 6- to 12 -volt d.c. source to terminals 2 and 4 ( positive voltage to terminal 2) and measure the d.c. voltage between point A and terminal 4.

It should be one -half the supply voltage. If it is not, R1 and R2 may not be matched closely enough. In this case, temporarily replace R1 with a 100,000 - ohm potentiometer and adjust the pot until the voltage at point A measures one -half the supply voltage. Then measure the resistance of the potentiometer and replace it with a fixed resistor of that value.

Modifications. You can add a volume control to the amplifier by connecting a potentiometer to the circuit between the


November, 1965 75

PARTS PROFILES By DON LANCASTER

COMPONENTS OF THE MONTH 'PARTS PROFILES" IS INTENDED TO PROVIDE YOU WITH EX- CITING INFORMATION ABOUT UNUSUAL OR LITTLE KNOWN ELECTRONIC COMPONENTS AND DEVICES THAT ARE INEX- PENSIVE, INTERESTING, AND USEFUL. THESE PRODUCTS WILL USUALLY ENABLE YOU TO BUILD MORE INTERESTING PROJ- ECTS AT LESS COST, IN LESS TIME, AND WITH IMPROVED PERFORMANCE. ALL ITEMS COVERED ARE AVAILABLE NA- TICNALLY OR FROM AT LEAST ONE RELIABLE SOURCE OF SUPPLY. -THE EDITORS

CERAMIC FILTERS REPLACE I.F.'S

CLEV11 E

TO-01A

Is an i.f. transformer a must in every superhet receiver? Not any more. You can now use a new resonant mechanical filter by Clevite that tunes automatically to the 455 -kc. i.f. in any transistor radio. It comes in two series (TO -01 and TO -02).

" Transfilters," as they are called, are tiny ceramic devices no bigger than your thumb- nail, and they never need alignment. Fea- tures include: low cost ($1.70 each); small size (3/4" x 5 /s" x 3/16 ", maximum); low insertion loss (less than 3 db) ; wide bandwidths (4 to 10 kc.) ; and availability of all standard input and output impedances.

The same manufacturer has also put out a resonant trap (TF -01) that can be used in place of the conventional emitter bypass capacitor in transistor circuits to increase the i.f. selectivity. Figure 1 shows. typical frequency response of a transfiltered i.f. stage in which both TO and TF transfilters are used. For a typical transistor i.f. circuit using the transfilters, refer to Fig. 2.

76

But transfilters are not limited to i.f. circuits; they have other applications. You can use one to make a test oscillator if you don't own a signal generator, or would like to have another signal source. Figure 3 shows a simple oscillator employing the TO -01 unit. This oscillator can be assembled and put into a pocket flashlight case, complete with penlight batteries, and can be used for signal injection or other test purposes.

40

30

? 20 fn

ó -J

10

o 410 420 430 440 450 460 470480 490

KILOCYCLES

FA 70-02A , 1

ril ....,20

,0,-04/11

v14

,

119171

gig

WITH TF -01 EMITTER BYPASS

WITH CAPACITOR EMITTER BYPASS

Fig. 1. Typical relative frequency response of trans filterized receiver i.f. stage. Note attenuation when Clevite TF -01 replaces emitter bypass capacitor.

You can get data sheets and application notes direct from the manufacturer, Clevite Electronic Components, 232 Forbes Rd., Bedford, Ohio. The retail outlet is Semicon- ductor Specialists, Inc., 5700 West North Avenue, Chicago, Ill. The TO types retail at $1.70 each, and the TF at $1.50.

POPULAR ELECTRONICS

FROM CONVERTER

33K

1.5mhy.d

2N139 R

4111 ,N60

2.2K

%.6

2.2K

AVC

+9VDC

00131.

AUDIO OUTPUT

Fig. 2. This transistorized circuit uses transfilters in place of conventional i.f. tr- 1 1- rrners. Insertion loss is less than 3 db, and bandwidths of from 4 to 10 kc. provide a selec.i.c cr high- quality i.f.

TO-OIA

AMPLITUDE MODULATED INPUT

(IF TEST .053f. I

Fig. 3. Test oscillator using a T0 -01 transfilter and a single transistor. The unit can be built and housed in a small pocket flashlight case, complete with penlight batteries and all, at a very low cost.

NEW SEMICONDUCTORS REPLACE TUBES

Here, at last, are the long- awaited equiva- lents of the popular 35W4 rectifier and the 5005 power amplifier vacuum tubes: the new RCA 40265 silicon rectifier and 40264 silicon transistor. With this double -bar- reled bombshell. RCA has tolled the death

knell for the vacuum tube in circuits com- monly used by the experimenter or hobbyist.

With these semiconductors, you don't waste the 13 watts of heater power that vacuum tubes consume, and which does nothing more than heat up the inside of your radio, phonograph, or what have you, and cook the life out of your capacitors and other components. What's more, the silicon units cost less than the tubes.

We are not saying that these semiconductors are precisely interchangeable with their tube counterparts. What we are saying is that they will perform every circuit function that the tubes will, and at the same voltage levels. RCA plans to use these two semiconductors (plus three more you'll learn about when you write for data sheets) as the basis for a line- operated all- solid -state AM radio, as well as in other consumer items.

Let's take a look at the 40265 rectifier first. When working with this baby, remember that you are playing with an a.c. -d.c. circuit


November, 1965 77

SOLID STATE By LOU GARNER, Semiconductor Editor

LAST MONTH we suggested that hobbyists and experimenters consider using some

of the low -cost silicon transistors on the market. And we listed some of the types that are available. Now let's go into them in a little more detail.

Texas Instruments' TI -411 through TI -414 are medium -power, high- frequency amplifiers, while TI -415 through TI -419 are low - level, low -noise amplifiers. General Electric's 2N2921 through 2N2926 and the GE -10 are all audio amplifiers. Of these, the GE -10 is the most readily available; this unit can be used as a general -purpose replacement for nearly all other low -cost silicon transistors. Motorola's MPS706 and MPS834 are switching types, and are quite suitable for use in r.f. or audio circuits.

All these transistors are encapsulated in molded epoxy with one side flattened, as shown in Fig. 1, to facilitate lead identification. As shown, currently available units feature in -line lead connections. These differ from the usual spaced lead arrangements used in such popular types as the 2N107 and 2N170.

Remember that all currently available silicon transistors are npn types, so if they are being used as direct replacements for pnp germanium types, the circuit power supply and electrolytic capacitor polarities must be reversed. Figure 2 shows a typical biasing arrangement you can use for an npn amplifier stage.

In general, silicon transistors have lower internal leakage than corresponding germa-

FLAT FLAT_ LETTERS MOLDED SIDE "

ON FLAT SIDE E B C

SIDE

C B E C

0 0 0 E C B

0 0, C B E B C

Fig. 1. Silicon transistors featuring in -line lead connections instead of usual spaced lead arrangement. Flattened side facilitates lead identification.

78

nium types. Moreover, many of the newer silicon jobs have very high beta (gain) ratings. For example, the TI -416 has a gain of over 600. If you put a silicon transistor in a circuit designed for operation with a germanium job, you may have to readjust the base bias to achieve optimum circuit performance. In the circuit shown in Fig. 2, the base bias can easily be readjusted by simply changing the Rl R2 resistance ratio.

If you check the spec sheets for the various transistors mentioned here, you'll come up with a wide set of ratings but you'll also find that each of the types has a power dissipation of at least 200 milliwatts, and a collector -to -base rating of at least 25 volts. What this all means is that you can use silicon transistors in most standard circuits, and in so doing get a moderate amount of power from the output stages.

Although we have been talking about the low -cost jobs, all that has been said applies to the higher priced silicon transistors as well. Naturally, some transistor lead arrangements vary, but their applications remain the same. So if you want to start out experimenting with transistors salvaged from the inexpensive surplus computer boards that many distributors are offering, go right ahead. Later, as you gain experience with silicon types, we think you'll agree that you'd "rather switch than fight."

Reader's Circuit. Who said simple AM broadcast -band receivers have lost their charm? Certainly not reader Cary A. Jave-

INPUT CI

Fig. 2. Circuit configuration of typical amplifier stage using a silicon transistor. Base bias is determined by resistance ratio of Rl /R2 combination.

POPULAR ELECTRONICS

,--Wnnnn RI

I.5MEG.

T

02 2N109

C5 .05yf.

CT lour.

+

R3 8zn

BI

I SI

ner (Rt. 1, Box 208 -A, Cameron, Wis. 54822), who submitted the general -purpose receiver circuit shown in Fig. 3. Cary says his little two -transistor "all- wave" radio does a superb job receiving amateur and s.w. bands, in addition to the standard broadcast band. The only requirement is that a new coil be substituted for each band since there are no provisions for switching.

Cary observed that the receiver's upper frequency is determined primarily by the characteristics of Ql as well as the inductance of the coils used. Tuning will be critical on the high bands unless a smaller tuning capacitor is used for C3, about 140 pf. or less, when working the high bands.

Unfortunately, Cary did not furnish specific coil -winding data, although he did indicate that he used a set of plug -in coils capable of covering from 550 kc. to 15 mc. However, the coils are nothing special; just keep the tap as close as possible to the base - end of the coil.

Let's look at the circuit. Coil LI and capacitor C3 comprise the r.f. tuning circuit,

MODULATION Fig. 4. Base -modulated oscil- INPUT

lator by Philco can be used in a sweep generator,

wireless mike, or transmitter circuit. Basically

a modified Hartley oscillator, the circuit produces

good frequency modulation linearity with modula-

ting voltage applied to the base of transistor Ql.

T2

Fig. 3. This two -transistor "all- wave" radio circuit was submitted by reader Cary Javener. Short-wave and standard broadcast -band transmissions can be received merely by changing the plug -in coil (L1) for each desired frequency band.

while Cl and C4 are just couplers. Capaci- tor C2 is variable from about 60 to 100 pf., and controls the amount of regeneration desired. Transistor QI is a 2N706A npn r.f. amplifier operated as a grounded emitter re- generative detector. It is base -biased by the drop across Rl. Interstage transformer Ti is an Argonne AR109, while output transformer T2, an Argonne AR164, was selected to match the impedance of the 8 -ohm speaker used.

Transistor Q2 is a 2N109 pnp unit that's being used as an audio driver; it is indi- rectly biased through R2 and R3. Capacitor C6 is an audio coupler, and C7 is an emitter bypass capacitor which reduces negative feedback; they are both 10 -volt electrolytics. Operating power is supplied by a single 9- volt battery, but you could use six penlight or flashlight cells in series instead. The on- off switch can be any s.p.s.t. type.

The receiver can be assembled on a regular metal chassis, on a perforated phenolic board, or even on an etched circuit board. It all depends on your own preferences,

01

C6 1005f.

RF OUTPUT

November, 1965 79

since neither layout nor lead dress is critical. But regardless of what you do elsewhere, you must follow good wiring practices in the r.f. section; that is, keep leads as short and direct as possible and properly dressed. And watch your polarities.

Cary swears that he was able to pick up amateur stations in Wisconsin, Minnesota, and Michigan using a 75 -meter coil wound on a ferrite core, and that almost any standard antenna can be used with his receiver. However, remember that the set's sensitivity, as well as its selectivity, will be gov- erned largely by the coils used, as well as by the skill of the operator in adjusting both the tuning (C3) and regeneration (C2) controls. In general, C2 should be adjusted to just below the point at which oscillation takes place.

Manufacturer's Circuit. Developed by Philco and described in Application Report $755, the base - modulated oscillator shown in Fig. 4 can be used in a sweep generator, wireless microphone, telemetry system, or transmitter circuit.

It is basically a modified Hartley oscillator, with Ql's base bias supplied by voltage divider R1 -R2. Here, the modulating voltage is applied to the transistor base, but equally good frequency modulation linearity would be obtained if the modulating signal were applied to the emitter. However, to get maximum utilization from even weak modulating signals, the base modulation technique is to be preferred. Furthermore, because some amplitude modulation is always present, regardless of what you do, limiters should be used to remove the AM peaks.

In Fig. 4, coil LI and capacitor C3 form a parallel tuned circuit whose frequency is determined by QI's internal collector -to- emitter capacity, the inductance of the coil, and the setting of C3. The interelectrode capacitance, in turn, is a function of the base bias which varies with the applied modulating signal. It can be seen, therefore, that the frequency of the oscillator varies with the amplitude of the modulating signal.

The oscillator is designed to operate at a center frequency of 30 mc., with a maximum deviation of 400 kc., and can be built with readily available components. For instance, transistor Ql is a Philco 2N502A unit, Cl is a 12 -volt electrolytic, C2, C5, and C6 are ceramic or mica capacitors, while C3 and C4 are small trimmers. Coil LI consists of 20 turns of B &W 3003 1/2"-diameter coil with emitter tap at 3 turns, and the output tap at 91/2 turns. Battery BI is rated at 12 volts; and all resistors are half -watters.

Transitips. In our October column, you may recall, we discussed some of the effects of harmonic distortion, and pointed out that 80

Fig. 5. These waveforms show what happens when two identical signals are handled by (A) linear (distortion -free) amplifier and (B) nonlinear amplifier.

a nonlinear amplifier can easily become a harmonic generator, producing frequencies that were not part of the applied signal. For example, if you put in a 1 -kc. note, you can get out harmonics at 2 kc., 3 kc., 4 kc., etc. We refer to them as second harmonic, third harmonic, and so on.

Now let's look at another type of distortion which is also due to the nonlinear operation of an amplifier. This is inter - modulation distortion, better known as plain I.M. In some respects, I.M. is more annoying than harmonic distortion, and can be a headache even when the harmonic distortion is within a tolerable level.

For example, suppose two signals, each of a different frequency, are applied simultane- ously to a distortion -free amplifier. One will merely be superimposed on the other, and the resultant waveform will be as shown in Fig. 5(A). Observe that the amplifier output signal contains only the original signals.

On the other hand, if the same two signals are passed through a nonlinear circuit, one signal will modulate the other, developing an output waveform similar to that in Fig. 5(B). This composite signal contains not only the two original signals, but also frequencies equal to their sum and difference. For instance, if the two original signals were 50 cycles and 1 kc., the output would contain signals at 50 cycles (original), 950 cycles (difference), 1 kc. (original), and 1050 cycles (sum).

The situation becomes even more complex when both harmonic and intermodulation distortion are present. The output waveform would then contain not only the sum and difference frequencies of all signals handled, but harmonics of these, harmonics of the original signals, and the sum and difference frequency signals of the various harmonics.

In terms of practical transistor amplifiers, harmonic distortion generally is caused by incorrect bias, overdrive, a defective transistor, transformer saturation, or a leaky coupling capacitor. Push -pull circuits can be used to minimize the effects of harmonic


POPULAR ELECTRONICS

Computer becomes a teacher

AS THE YOUNG MAN sits facing the computer, a punched paper tape is

drawn through a photoelectric reader. Now the electric typewriter tied into the computer takes over. The young man shifts slightly forward to read the question that has been typed out. He ponders the question for a moment and then types back his answer. The computer, through the typewriter, responds:

"Your answer is incorrect. At your earliest convenience read pages 74 -79 in your textbook. Try again."

The young man described above is using ALPHA -COM, a teaching program which permits a question- and -answer re- lationship between the student and the

November, 1965

computer. The computer's arithmetic and logic circuits evaluate the answers, deciding whether they are right or wrong. If an answer is right, the computer types the next question. If wrong, it types back an appropriate reply and tells the student to try again. Some typical ALPHA -COM replies are:

"Read the question again, more carefully."

"You are guessing. Try again." "Ask your instructor for additional

reading assignments." ALPHA -COM is neither expected nor

intended to replace human instructors but is a powerful teaching aid that makes the learning process faster and

81

easier. Developed at Northwestern TV and Electronics Institute of Minneapolis, Minn., it enables the computer to test a student's knowledge, to call attention to his errors, to evaluate his performance by calculating a numerical grade, and to make recommendations for further study. Because Northwestern trains technicians for employment in the electronics industry, the original ALPHA -COM program contains questions relating to electronics theory. It can, however, be easily modified for other subject areas.

A compassionate but demanding teacher, ALPHA -COM (for ALPHAnumeric COnversational Mode programming) will always give the student a chance to "try again" after an incorrect answer, but it insists on a correct answer before going ahead to the next question. Not only can the computer recognize an incorrect answer, it can recognize an illegitimate answer -one that has nothing to do with the question it has asked. It will respond to such an answer by typing out a reprimand to the student, and it will tolerate two such attempts to be "cute." The third time, it will summon

the human instructor by repeated ring- ing of a bell. Only manual intervention by the instructor (he types a special code number) will stop the bell and restore question- and -answer operation.

While the giants of the computer industry direct their major efforts toward business and industrial applications, educators are more concerned with the computer as a teaching machine. It is not difficult to imagine a future installation consisting of dozens of typewriter - equipped stations connected to a central computer which would have sufficient memory capacity and input /output circuitry to handle a whole class of students at once. The computer would com- municate with each student individually, allowing each to progress at his own rate, and directing some back to earlier lesson material for review. It would also calculate students' grades and retain these in memory for later reporting to school officials. All this is not mere speculation -it can be done today by any school having computer- oriented personnel and sufficient funds for the necessary hardware. -Ed Bukstein

GET THAT BEAM ANTENNA SHOT THERE ARE three very good reasons

for taking a photo of your brand -new beam antenna. First, you might find a magazine willing to publish the shot (don't laugh -it happens every day) ;

second, you might fit the photo into your next QSL card; but the third reason may be most important. When that antenna went up, so did your insurance liabilities. Not only is a beam a hazard ( children always try to climb the tower), but have you considered the cost of

replacement ? Are the tower and beam insured ? If they are, how can you approximate their value- without a photo that an expert could appraise?

Taking antenna photos is not an easy task. Most amateur photographers need reminding that black and white films don't "see" the same things against the bright sky as the human eye. Filtering is called for ( see caption) , and be sure to shoot when the sun is glancing light off the elements toward the camera. 30

The photo on the left was taken with 35 -mm. Plus -X and a setting of 1 /100 sec. at f16 -no filtering. On the right is the same scene shot several minutes later with a Kodak Wratten Type A filter at 1 /100 and f5.6. Note darkened background and howthe elements stand out against the sky.

DON'T TUNK YOUR OLD FM TUNER UPDATE IT FOR LAND MOBILE RADIO SERVICES

By CHARLES E. FRANCIS, K8VRX

HAS YOUR FM tuner been made obso- lete by the recent onslaught of

vastly improved FM and FM stereo receiving equipment? Then spruce up that old tuner and snoop in on police calls, fire, civil defense, weather reports, and rescue squad operations for sheer pleasure or wild excitement. The simple modifications described here will enable you to change the tuning range of any variable- capacitor -tuned FM tuner or receiver to pick up high -band Land Mobile radio services ( see "Hats Off to VHF," August, 1965) . It should take less than 30 minutes.

This conversion to receive the 152- to 174 -mc. band is designed to maintain the standard 10.7 -mc. intermediate frequency. The i.f. section of the tuner need not be realigned. However, to avoid getting lost in tracking and other problems, you should be certain that your tuner or receiver is in good working order before you begin the conversion.

The procedure is basically the same for any variable- capacitor -tuned tuner. regardless of make or model, the only

Fig. 1. The tuner front panel, dial cord, and dial -cord pulley can be removed to provide adequate working space. In most cases, it will only be necessary to remove the tuner chassis from the cabinet to gain access to tuning capacitor and coils.

November, 1965

difference being in the number of turns for the r.f. or oscillator coil. While it is easier to pinpoint the effects of your modifications with a grid dip meter or other frequency- measuring device, in most instances you will be able to find your way simply by noticing the effects of each adjustment. The Heathkit Model FM -3 tuner, typical of a great many units now in use, responded very well to this treatment.

Converting the Tuner. The modifications are simple and consist of the following four steps:

(1) Remove the tuner case, and all components necessary to gain access to the tuning elements. Do not remove more than you have to. Figure 1 shows the front panel, dial cord, and dial -cord pulley removed to give you a better view of the parts to be modified.

(2) You will note that the tuning capacitor (Fig. 2) has two sections, the front being the r.f. section, and the rear the oscillator section. Using a pair of long -nose pliers, carefully remove one rotor end plate from each section. These

83

OSCILLATOR FREQUENCY ADJUST

OSCILLATOR COIL (2 TURNS)

COIL TAP

RF COIL (2 TURNS)

Fig. 2. These components determine the operating frequency of the tuner. The coils are adjusted by compressing or expanding the turns as necessary for good frequency coverage and tracking in the band.

plates are press -fitted into place and can be gently worked out of their positions. It should not be necessary to twist, bend or break the plates. Caution: Do not bend, loosen, or otherwise damage the other plates. If possible, do not even touch the other plates. After removing one plate from the rotor in each section, there will still be two rotor and two stator plates left in each section. (If your tuner has a different -size variable capacitor with a different number of plates, the procedure is still the same do not remove more than one plate from the rotor in each section.)

(3) Remove the r.f. coil and replace it with a two -turn coil formed by wrapping a piece of ;$16 solid copper wire around an ordinary pencil. Stretch the coil turns to a length of 'iíu inch, leaving a short pigtail for connection.

(4) Remove the oscillator coil and replace it with one formed by wrapping two turns of 16 wire around a pencil. Stretch the turns to 153z inch across. Reconnect the oscillator coil tap at the center of the coil, and reassemble the components and hardware, but do not put the tuner back into the case.

Except for an air check and a few adjustments, your conversion is completed.

Antenna Considerations. For optimum performance, a highly directional antenna aimed at the station you are listening to is ideal; but with signals coming at you from different directions, you are better off with a ground plane or other omnidirectional antenna. The ver-

tical antennas usually have a 52 -ohm impedance and call for a 52 -ohm coaxial transmission line. If you do go for the 52 -ohm job, insert a 52 -ohm to 300 -ohm matching transformer between the line and the set, at the set's antenna terminals.

An ordinary indoor TV 300 -ohm antenna can be used quite effectively, if you telescope the elements down to proper size. Simply adjust the length and direction for maximum volume.

Touch Up and Tune In. If the tuner works perfectly when you connect the antenna, go no further -you're in! But most likely you'll have to do a little touching up of the coils and /or trimmers. Here's what you do:

(1) Tune in a station near 170 mc. and carefully adjust the oscillator trimmer to bring in the station near the high end of the band. If you can't bring in the station where you want it when adjusting the trimmer, try expanding or contracting the length of the oscillator coil to move the station down or up, respectively.

(2) Adjust the r.f. trimmer for maximum volume and clarity. If you have the feeling that you could get more out of the r.f. trimmer by tightening it a wee bit but you can't because it is already screwed all the way down, just back off about a turn and a half, com- press the r.f. coil a little and try the trimmer again. (Of course, you can expand the coil if the trimmer is wide open and still doesn't seem to be open enough.)

(3) Now try tuning in a station at the low end of the band. If the station comes in, that's it. If it doesn't, you may have to shift the tuning range up a bit more. It's easy; the oscillator adjustments shift the band up or down the tuning scale and the r.f. stage peaks the signal.

Should you run into tracking problems, such as good volume and clarity at one end of the band and not at the other, select a station in the middle of the band and, with the variable capacitors set in mid position, adjust the oscillator and r.f. coils and trimmers for maximum volume and clarity. Any tracking errors still present will be reduced by about 50%. --


Why depend on batteries when you can get all the energy you need free of charge? Hun'?

LET THE SUN POWER YOUR PORTABLE By HOMER L. DAVIDSON

November, 1965

V OU CAN USE the sun to power your I small transistor radio--or, if it's

raining, you can use o 100-watt light bulb. The only other element you really need is International Rectifier Corpora- tion's "Solar Pac," which can be hooked up to charge the radio's battery, or to operate the radio, or to do both. The "Solar Pac" comes in two models: SP5C26C (4.5 volts at 26 ma.) and SP9C13C (9 volts at 13 ma.), and is available from electronic supply houses for $9.95.

There are many ways you can connect the solar pack to your radio. You may

85

want to add a switch (see schematic) to provide a choice of either solar or battery power. Or you can simply connect the pack's 6" leads to the battery connections inside the radio. You can even use the solar pack as a plug -in supply by connecting an earphone jack and cord to the pack, removing the existing wires from the radio's earphone plug, and running a pair of wires from the plug to the battery connections.

Mounting the pack is no problem as it is supplied with mounting pads which can be attached easily to any radio case

Hook up a couple of alligator clips to the leads of the solar pack to make easy -to- connect power supply.

By connecting the solar pack in parallel with the battery, you can charge the battery while operating the radio, or run the radio without the battery.

The earphone jack connections of your transistor radio can be modified to accommodate the solar pack.

86

TO RADIO 4

SLIDE SWITCH O

1±I IIHr

SOLAR PAC

9V

Your portable can be switched to either battery or sun operation by adding a slide s.p.d.t. switch.

or cover. But for a more permanent installation, place the pack against the plastic back of your radio, outline its shape with a scribe, carefully cut out the required area with a knife -tipped soldering iron or jeweler's saw, fit the pack into place, and seal around the edges with cement.

If you plan to use the solar pack as a universal power supply for more than one radio or transistor project, add alligator clips to the pack's leads for easy handling. Should circumstances require lower voltages than that provided by the solar pack, insert an inexpensive 100 -ohm potentiometer in series with the output to reduce the voltage.

Once you know how much resistance you need in a given circuit (by measuring the pot's resistance in the circuit) ,

you can substitute a fixed resistor. Add a resistor only when no battery is in the circuit, and only when the unit is to be used out -of- doors. A resistor is not required indoors as you can move closer to or further away from the light source to obtain a desired voltage.

The solar pack can be cemented to the radio case, and the leads can be slipped under the case flap.

POPULAR ELECTRONICS

SHORT -WAVE LISTENING By HANK BENNETT, W2PNA /WPE2FT Short -Wove Editor

SAFETY RULES FOR SWL'S

EVEN short -wave listening can be a dan- gerous sport. There are many ways in

which an SWL can be accidently injured in the pursuit of his favorite hobby- particu- larly while making repairs or installing an antenna.

One of the most common types of accidents, fortunately not usually too serious, involves those who insist on probing into their receivers while the power is on. It can be done if you know what you are doing. Unfortunately, it usually takes a few jolts to make some people have more respect for those innocent -looking capacitors.

The safest way to examine a faulty piece of equipment is with the power off. The best thing to do is pull the plug and ground the capacitors before you stick your fingers inside the receiver.

No expert electronics man has gone through life without being walloped by B -plus, or tickled silly by the a.c. power line, or burned by a hot tube. It's smart business to learn from the mistakes of others, because you may not live through one of your own.

The antenna, too, can become an accident machine. We recently received a letter from a mother whose son was electrocuted while

erecting an antenna. So slow down and walk away from an installation that can come in contact with a power line. The operator who lost his life may have noticed the nearby power line, and he may have assumed that it couldn't happen to him. What he should have done was to get far enough away from the power line to prevent contact even if the antenna toppled over.

And there's always the risk of falling out of a tree, or off a ladder or roof when you're putting up an antenna. Be sure the ladder is firmly footed and the tree is firmly planted before you climb. It may be embarrassing to find yourself up a tree, or out on a limb, or hanging from your fingernails over the edge of a roof -even if you don't fall. It's a good idea to use the buddy system. Invite a friend over and let him at least hold the ladder for you. Should you become stranded and not be able to get down safely, he will be able to call the fire department to rescue you.

In most cases, just plain common sense goes a long way towards preventing accidents. So take time out to examine a situation before you get involved in one.


Above: David Berger, WPE3GJO, Wilmington, Del., DX'es with a Lafayette KT -340 backed up by a

Knight -Kit "Star Roamer." His antenna: a 126' Win- dom. His record: 31 countries logged, 22 verified.

At right: The Hallicrafters SX -110 receiver shown belongs to Wayne White, WPE7CDS, of Safford, Arizona. Wayne's antenna is a 3 -way long -wire. He has 30 countries logged, 29 of which are verified.

November, 1965 87

ELfCTV

O á A_ a Z c PROVINCES f') VERIFIED y

% O 1. eLp'

DX AWARDS The third in our series of DX Awards is an all -Canada award and is based upon having at least one verification from each of Canada's provinces. The rules and regulations are basically the same as for the previous contests, but you should read them carefully to make sure you follow the correct procedure. If you do not yet have a Short -Wave Monitor identification, you'll find an application blank on page 127 in this issue.

1 Each applicant must be a registered WPE Short- Wave Monitor, and must enter his identification sign on the application forni (or facsimile).

2 Each applicant must submit a list of stations (any frequency or service) for which he has received verifications, one for each heard and verified. The list should contain 6, 8, 10, or 12 provinces, depending on which DX award is being applied for. The following information must be furnished in tabular form and in alphabetical order by province for each verification:

(a) Province heard (b) Call -sign of station verified and location (c) Frequency (d) Date station was heard (e) Date of vertification (postmark dates ac-

ceptable) All the above information should be copied from the station's verification. Do not list any verification you cannot supply for authentication on demand. The provinces of Canada deemed acceptable are: Alberta, British Columbia, Labrador, Manitoba, New Brunswick, Newfoundland, Nova Scotia, On- tario, Prince Edward Island, Quebec, Saskatchewan, and either Yukon or Northwest Territories.

3 All pertinent verifications, whether QSL cards or letters, should be carefully packaged and stored by the applicant until such time as instructions are

received to send in some or all of them for check ing purposes. Instructions on how and to whom to send the verifications will be given at that time. Failure to comply with these instructions will dis- qualify the application.

4 A fee of 50 cents (U. S. coin or stamps) must accompany the list of verifications to cover the costs of printing, handling, and mailing. This fee will be returned in the event an applicant is found to be in- eligible for an award. Applicants outside of the United States may send 60 cents (U.S.) in coins of their country if they so desire. Please do not send International Reply Coupons (IRC's).

5 Apply for the highest DX award for which you are eligible. If, at a later date, you become eligible for a higher award, then apply for that award, following these rules and regulations exactly as before.

6 Mail your verification list, fee, and the application form to: Hank Bennett, Short-Wave Editor, POPULAR ELECTRONICS DX AWARDS, P. O. Box 333, Cherry Hill, N.J., 08034. Include in the envelope only those items which are directly related to your entry for the award. Do not include an application for a Short -Wave Monitor Certificate (you are not eligible for any of the awards until you have a

Monitor Certificate). If you want to supply news items, reports, etc., please use another envelope.

POPULAR ELECTRONICS' DX AWARD APPLICATION FORM (please print)

WPE Identification Name

Address City State Zip Code

Please enter my application for the following POPULAR ELECTRONICS' DX AWARD:

(check one( 6 1

I 8 Ii I have enclosed a list of the required number of provinces, and I hereby certify that I hold a verification from at least one station (any frequency or service) in each of the provinces listed

I have enclosed 50 cents to help cover the costs of processing and mailing my DX Award

Signature Date 1965

Mail to Hank Bennett, POPULAR ELECTRONICS DX AWARDS, P. 0. Box 333, Cherry Hill, N. J.


ENGLISH -LANGUAGE NEWSCASTS TO NORTH AMERICA Prepared by ROBERT LEGGE

All of the stations below have announced English -language newscast programs at the times and on the frequencies given. Note a number of changes in the setup of the listing from our previous editions: use of EST in the colloquial a.m. and p.m.; use of mc. instead of kc.; and a division of transmissions beamed to the eastern and central parts of the U.S. from those beamed toward the west coast. Some additional broadcasts are beamed to North America, but are not included in this listing since they are not expected to be heard satisfactorily during the writer months. -THE EDITORS

COUNTRY CITY TO EASTERN AND CENTRAL NORTH AMERICA

TIME -EST TIME -GMT FREQUENCIES (MC.)

ALBANIA Tirana ARGENTINA Buenos Aires AUSTRALIA Melbourne BULGARIA Sofia CANADA Montreal CHINA Peking CUBA Havana CZECHO-

SLOVAKIA Prague

DENMARK Copenhagen FINLAND Helsinki GERMANY Cologne HUNGARY Budapest

ITALY Rome JAPAN Tokyo NETHER-

LANDS Hilversum

NORWAY Oslo PORTUGAL Lisbon SPAIN Madrid SWEDEN Stockholm

SWITZERLAND Berne UNITED

KINGDOM London

U.S.S.R. Kiev Moscow

VATICAN CITY Vatican

7 p.m. 10 p.m. (Mon.-Fri.) 7:45 a.m. 7 p.m., 11 p.m. 7:15 a.m. 8 p.m., 9 p.m. 10 p.m.

10 a.m. (Sun.) 8 p.m., 10:30 p.m. 7:30 a.m. 7:15 a.m. (Tues., Sat 8:30 p.m. 7:30 p.m., 8:30 p.m. 10 p.m., 11:30 p.m. 8 p.m. 7 p.m.

4 p.m. 8:30 p.m. 11 a.m. (Sun.) 9 p.m., 10:45 p.m. 8 p.m., 9 p.m. 9 a.m. 8 p.m. 8:15 p.m.

0000 0300 1245 0000, 1215 0100, 0300

(Tues. -Sat.)

0400

0200

1500 (Sun.) 0100, 0330 1230

.) 1215 (Tues. -Sat.) 0130 0030, 0130 0300, 0430 0100 0000

2100 0130 1600 (Sun.) 0200, 0345 0100, 0200 1400 0100 0115

11 a.m. 1600 5 p.m., 6 p.m. 2200, 2300 7 p.m., 9 p.m. 0000, 0200 7:30 p.m. (Mon., Thurs.)0030 (Tues., Fri.) 5 p.m. 2200 6 p.m., 7 p.m., 8 p.m. 2300, 0000, 0100 9 p.m., 10 p.m. 0200, 0300 11 p.m., 12 Mid. 0400, 0500 7:50 p.m. 0050

7.265 9.69 9.58 6.07 5.97, 11.72, 15.32 7.035, 9.48 6.135

15.285, 15.448, 17.825 5.93, 7.12, 7.345

15.165 15.185 6.075, 9.64 7.305, 9.833 7.305, 9.833 5.96, 9.63 11.78, 15.135

6.085, 9.59 9.59 (via Bonaire relay) 15.175, 17.825 6.025, 6.185 6.13, 9.615 15.195 5.99

6.08, 6.12, 9.535

11.84, 15.30 6.195, 7.13, 9.51, 9.735 6.195, 7.13, 9.51, 9.735 7.31, 9.665 7.15, 7.31, 9.665 7.15, 7.205, 7.31 6.07, 7.15, 7.31 7.15, 7.31, 9.665 5.985, 7.25, 9.645

COUNTRY CITY

TO WESTERN NORTH AMERICA TIME -EST TIME -GMT FREQUENCIES (MC.)

ARGENTINA Buenos Aires AUSTRALIA Melbourne CHINA Peking

Taipei CUBA Havana GERMANY Cologne

JAPAN Tokyo KOREA Seoul SPAIN Madrid SWEDEN Stockholm SWITZERLAND Berne THAILAND Bangkok U.S.S.R. Moscow (via

Khabarovsk)

10 p.m. (Mon.-Fri.) 6:30 p.m., 7:30 p.m. 7 p.m., 8 p.m. 6:50 p.m. 9 p.m. 7:10 a.m. 8:55 p.m. 7:15 p.m. 7 p.m. 7 p.m. 6:30 p.m. 7 a.m. 8:15 p.m. 7 p.m., 8 p.m. 9 p.m., 10 p.m.

0600 (Tues. -Sat.) 0230, 0330 0300, 0400 0250 0500 1510 0455 0315 0300 0300 0230 1500 0415 0300, 0400 0500, 0600

9.69 15.22, 17.84 7.08, 9.457 9.685, 11.825, 15.345 6.135 9.735, 11.795 6.145, 6.16, 9.575 11.78, 15.135 11.925 6.13, 9.615 5.99 15.305 11.91 9.54, 9.735, 11.85 9.54, 9.735, 11.85

November, 1965 89

a ( By MATT P. SPINELLO, KHC2060, CB Editor

ON THE CITIZENS BAND

N THE April edition of this column, we began an unofficial campaign to bring the

facts about CB radio to the attention of the general public through AM broadcast station interviews. The project was primarily designed to explain the Citizens Radio Ser- vice, its purpose, and especially the manner in which it is being used in public service and emergency activities. Following two

kick -off interviews in which we were al- lotted 30 minutes per segment to "spread the word," we encouraged every CB

club in the country to approach their local AM stations with a similar proposal: to be interviewed, discuss and answer questions about CB radio as its users know it.

Just recently Jane Neubauer, the charm- ing hostess of "Tete A Tete," a daily television information program, heard of our past discussions over AM radio stations WBEL and WOBT, and asked that we join her at WREX -TV in Rockford, Ill., to fill her audience in on "what this CB business is all about!" The pleasure was ours!

Prior to videotaping the show, we felt quite confident that we were in good hands

PROJECT INTERVIEW

ON TV

upon learning that the audio and video engineers, Don and Jerry Meinders, and the director of the show, Guy Fiorenza, were all licensed Citizens Band operators. Dur- ing the near quarter -hour telecast, we were able to cover the advent of CB, its primary purpose and uses, its growth and expanding applications in the realm of emergency assistance.

Jane and her audience were shocked -but interested -to learn that there are 850 REACT emergency teams across the country; 1000 H.E.L.P. volunteer units; 1000 CB clubs actively engaged in public service and emergency assists; and 3 million potential "assistants" ready to volunteer if and when needed. In fact, as a result of the interest stimulated by our first telecast, Jane has invited us back for another session to be devoted strictly to the emergency uses of CB radio.

We suggest that club officers review our April OTCB column; and we urge all clubs. teams, or groups to plot an interesting program for AM radio and /or television. Be sure the plotting is done before approaching the program director. And keep in mind that a good television interview demands good video -your handsome profile with a

90

"Tete -a- Tete" hostess Jane Neubauer and CB Editor Matt Spinello discuss the birth, growth, and multiple uses of CB radio on a quarter -hour telecast that was designed to promote "Project Interview."

POPULAR ELECTRONICS

The building in the background is the main control center for 13 base stations located throughout the St. Louis (Missouri) Zoo. The sea lion in the fore- ground appears to be imitating the antenna, a Mos- ley "Devant -1," perched on the roof of the building.

microphone sticking from your ear is not enough. Take along a set of clear pictures showing your group in action. If possible, bring an older -type handmade CB transceiver to compare with a modern -day piece of gear.

We would appreciate receiving copies of scripts used or a tape dub, if possible. At least, send us the details of your interview along with the results. A good, clear photo- graph would also be appreciated. Be sure to include names, addresses, and other pertinent information.

Our thanks to Miss Neubauer, WREX- TV, and the TV /CB crew that enabled us to add "video" to "Project Interview." If half of the active Citizens Band clubs across the country were to participate in the project on a local level through area AM /TV facilities, an uninformed public of millions might better understand our communications position before the year is out.

CB Safeguards Animals. We've never been associated with the minority of critics who theorize that "CB has gone to the dogs."

We recently became aware, however, that Citizens Band radio has definitely come to the aid of a large variety of animals paral- leling Noah's assortment on the ark. KDT0340 is the call -sign of the St. Louis (Missouri) Zoo. The grounds employ 13 base station transceivers, two mobile truck units, and several walkie- talkies.

The main control station is identifiable to the eye only by the Mosley "Devant -1" base station antenna perched on the roof of one of the refreshment stands on the grounds. The 12 other base stations spread throughout the zoo can be reached by this center or can contact one another through the same control station. In the old days (before CB), a refreshment stand that ran short of supplies was forced to wait for a supply boy who made regular rounds on a motor scooter. A considerable wait often meant loss of profit to the stand plus the loss of friendship on a warm day from the little tyke who wanted that bottle of soda pop "now." Today, a press of the CB mike button, a short transmission, and supplies are on the way in short order.

Workers at each refreshment stand collec- tively have a wide area view of the entire zoo, enabling them to relay malfunctions of the parking gates or any discrepancies at any of the animal pens within view. Plain- clothes policemen patrolling the grounds can also be contacted through any one of the 13 base stations.

The watchmen who guard the zoo at night contact one another by means of CB walkie- talkies. If one needs help, the other can be on the scene usually in seconds. Also, there are times when temperatures within the zoo need regulating due to the unusual demands of some of the residents. If a furnace needs adjustment, one guard can contact another for assistance, or ask the other to cover his post while he is temporarily occupied.

When animals arrive for the zoo at the St. Louis Lambert Airport, a CB- equipped zoo truck crew meets the airplane, examines the animals, then relays their condition and informs the zoo of any special preparations that must be made for the new residents while they are being transported ten miles to their new home.

The St. Louis Zoo has found Citizens Band radio invaluable for its purposes. The operation of CB behind the scenes helps bring efficiency to the world- famous insti- tution.

Area Call Books. Our old friend, Mel Baer, of K9TVA Enterprises advises us of the availability of cross - referenced Class D CB license directories for several FCC areas.


November, 1965 91

HAM HOBBY CLEARINGHOw

NEW POPULAR ELECTRONICS FEATURE

A couple of months ago the Editors of POPULAR ELECTRONICS offered to set up a clearinghouse for hams with other hobbies if there was enough interest shown in such a service. Since then the postcards have been coming in, as evidenced by the listings below.

If YOU have a second or third hobby that you would like to talk about on the air, tell us about it, or them. We believe that, through this clearinghouse, other hams who have the same interests will try to contact you. By the same token, the information ap-

pearing here should enable you to in- itiate some calls of your own -to those radio amateurs who have the same hobbies that you do.

To be listed here, just send us a postcard with the following information typed or printed on it: your call letters, other hobbies, the frequencies on which you operate, mode of operation, when you're on the air, and your name and address. Send the card to: Ham Hobby Clearinghouse, c/o POPULAR ELECTRONICS, One Park Avenue, New York, N.Y. 10016.

WA2FAS- Flying, coin and stamp collecting, and water sports; 80 to 10 meters, 20 and 15 meters SSB; evenings and weekends, Friday evenings preferred. (Gary Goldberg, 221 Clark St., Hillside, N.J., 07205) WB2KPO- Astronomy, photography, and hi -fi; 75, 40, and 20 meters, SSB; weekends and after school on weekdays. (Howard Lester, 245 Rumsey Rd., Yon- kers, N.Y. 10701)

WB2LHH- Electronic equipment, especially older models; 14,290- 14,320 kc., SSB; 11 a.m. to 2 p.m. Sundays. (R. I. Palluth, 398 Manor Rd., Staten Is- land, N.Y.)

WB2NIN- Medicine, medical electronics, science, and hi -fi; 80 and 40 meters, mostly CW, sometimes AM; 8 -10 week nights, 1 -5 Saturday afternoons. (Dr. Maurice J. Small, 158 S. Harrison St., East Orange, N.J. 07018) WB2NRX- Photography and SWL'ing; 40 meters, CW; afternoons from 4:30 to 5:30. (Henry F. O'Meara, 21 Glendale Rd., Brockport, N.Y.)

WB2ODI -BCB DX'ing; 75 -15 meters, phone and CW. (Chris Schmink, Williamsville, N.Y. 14221)

WB2OVI -Hi -fi /stereo, and project construction; 6 meters, phone; Friday afternoons and Sundays. (Alan R. Sandler, 861 E. 27 St., Brooklyn, N.Y.)

WB2RBA -Model rocketry and photography; 75 meters phone, and 80 meters CW; would like to start a net of teen -agers on 75 meters. (Joe Malloy, 474 Pacific St., Massapequa Park, N.Y. 11762)

WN2TDA- Archery and reading; 40 meters; 5 -10 p.m. during the week and all day weekends. (Bill Dundas, 2 Stiles St., Painted Post, N.Y.)

K3ZLB /5 -Radio and ham TV, scuba diving, archery, leathercraft, and hunting; fixed and mobile on any band from 80 to 2 meters, AM, CW, and SSB, and 424 mc. TV; weekdays after 2400 GMT, weekends after 2000 GMT. (Joseph M. Sweet, 9312 A. Wolff Ave., Ft. Bliss, Texas)

92

WA3AZI- Aviation and space topics, archery, home construction projects; 40 and 15 meters, CW; nights and weekends. (Michael Griffin, 715 Webb St., Aber- deen, Md.)

WN4YKA -Stamp and coin collecting, chemistry, and camping; 80, 40, and 15 meters; weekdays after 1900 EST, all day weekends and holidays. (Roy L. Moore, 307 Nunn St., Hazard, Ky.)

WB6CWR- Glider flying and sailing; 40, 20, and 15 meters, CW. (Larry Miller, 14918 Kingsley Dr., Gar- denia, Calif.) WB6IAD- Surfing and skateboarding; 40 meters, CW; 1 to 3 a.m. and 12 to 2 p.m. (Charles Smith, 427 Serra Dr., South San Francisco, Calif. 94081)

K7LPO /7- Science and math; low end of 80 -meter band; evenings. (LeRoy Taraba, 155 W. Jackson St., Monmouth, Oreg.)

WA8RER- Astronomy, photography, and amateur rocketry; 6 and 2 meters, AM and CW; any nights from 7 to 10 p.m. (Kenneth J. Burgess, 15577 O'Conner, Allen Park, Mich.)

WN8PWF- Boating and beagles; 7.15 and 7.2 mc. from 0530 to 0700 GMT; monitors 7.153 mc. (Art Colby, 525 Maple St., Saugatuck, Mich.)

WA9NDU -Stamp collecting and science fiction; 80, 40, and 2 meters. (Bruce Mocking, 5248 Arcadia St., Skokie, III. 60077)

WA9NDV- Astronomy, reading, swimming, and skiing; 20 meters, CW and AM, and 15 meters, CW; after 4 p.m. daily. (Joe Larson, 410 Lawrence Ave., Rothschild, Wis.)

W0DQI- Telephone band communications; would like to start club; phone 515 -232 -0161; no collect QSO's accepted. (Edward C. Booth, Route 1, Ames, Iowa 50010)

VE2BJP -Stamp collecting and 8 -mm. movies; 20 meters, AM. (Gerard R. Labelle, 1716 Avenue De Grosbois, St. Bruno, Comte Chambly, Canada)

POPULAR ELECTRONICS

- - - -- -- - - - - - - - - - -- - - - AMATEUR RADIO By HERB S. BRIER, W9EGO Amateur Radio Editor

USEFUL TIPS ON CONTEST OPERATING

FOR THOSE HAMS who like competition, the most enjoyable part of amateur

radio is contest operating. In the next month or so, two of the year's biggest contests are scheduled. They are CQ's "World - Wide DX Contest" (CW and phone), and the ARRL's "Section Sweepstakes Contest" (CW and phone). If you intend to work any of these contests in a big way (the CW and phone contests are separate activities), write to the sponsors for official score sheets and rules, including a stamped, self - addressed, business -size return envelope with your request.

The WWDX phone contest starts at 0000 GMT, October 23, and ends at 2400 GMT, October 24; the CW contest runs from 0000 GMT, November 28, to 2400 GMT, Novem- ber 29. You obtain the log sheets from and mail your scores to: WWDX, CQ, 14 Van - derventer Ave., Port Washington, L.I., N.Y. 11050. The SS phone contest starts at 2100 GMT, November 13, and ends at 0300 GMT, November 15; the CW contest runs from 2100 GMT, November 20, to 0300 GMT, November 22. You obtain the log sheets from and mail your scores to: SS, ARRL, 225 Main st., Newington, Conn. 06111. In each contest, you operate for any 24 -hour period.

To make a winning score in any of these

contests requires both good equipment and good operating, although it is possible to have fun with simple gear. In a DX contest, the competition from high -power stations is almost overwhelming on the 80 -, 40 -, and 20 -meter bands, except in the pre -dawn morning hours. But the competition is less severe on 15 and 10 meters -especially the latter, when it is open. And you will give yourself a better chance if you concentrate on less "exotic" DX like Bermuda, Eng- land, and Germany, which the big wheels have already worked, rather than countries like Afghanistan, etc., which everybody needs. In the SS contest, competition for individual stations is less severe than in the DX contest; therefore, transmitter power is not so important, and most experienced SS'ers use less than 150 watts to obtain the lower power multiplier (phone scores are multiplied by 1.5 if transmitter power is less than 150 watts, CW scores by 1.25).

Ordinarily, in a contest, an operator doesn't tarry after a CQ. If he doesn't hear a reply immediately, he CQ's again or moves to another frequency. As a result, if you have to throw several switches to get on and off the air, you will usually be left at the post. For the same reason, long calls are unnecessary. In situations where many operators are calling the same station, too

Garry Shandling, WA7BKG, of Tucson. Arizona, was the winner of the Arizona Section Novice award in last year's "SS" contest. WA7BKG worked 42 states as a Novice; as a General, he has added 9 states and 15 countries to his total. He uses a Hallicrafters HT- 44 SSB /CW transmitter and a SX -111 receiver plus a vertical antenna. Garry will receive a one -year subscription for this winning entry in the Amateur Sta- tion of the Month contest. If you would like to enter, send us a clear picture of your station -preferably showing you at the controls -and some information about your amateur career and your equipment. Mail your entry to: Amateur Photo Contest, c/o Herb S.

Brier, W9EGQ, Amateur Radio Editor, P.O. Box 678, Gary, Ind. 46401.

AMATEUR STATION OF THE MONTH * Vn- ;

November, 1965 93

Old -timer Walt Severin, W9SCV, Evanston, Ill., has all states and 45 countries worked. Featured among his gear are a Hallicrafters HT -37 SSB transmitter, a Collins 32V3 for AM, a Hammarlund HQ -170A receiver, and a Mosley TA -33 tri -band beam antenna. Walt is a member of the Professional Loafers club.

Angelo Miranda, Jr., WB2JHC, New York, N.Y., operates from the 8th floor of a 20 -story apartment building with a 35' wire run outside the building. His log shows 31 states, Germany, and Guatemala worked. His transmitter is a Knight -Kit T -150.

many of them make excessively long calls in the hope of outlasting the competition. A better method is to make a series of short calls with pauses between them to see what the called station is doing until it answers you or someone else or has apparently left the frequency.

A common mistake is to keep calling the same station time after time. Usually, it is wise to write off a station you can't raise with a reasonable number of calls, and stalk another station. Chances are the next time you run across the first station, it will be easy to raise.

One of the neatest tricks of contest operating when done properly is "tail- ending." Just as station A signs off with station B, you give station B a snappy "one -by -one" call on A's frequency. Station B pauses mo- mentarily to log your call letters before he sends his "final" to station A, after which he works you. Obviously, tail- ending takes real skill; if you call too soon, you will interfere with the contact already in

94

progress, and tic called operator will ignore you -if he is a good operator. And if you do it too often, he will place you on his never -work list. Conversely, if you call too late, the station you want will already be transmitting. Further complicating the problem, some operators refuse to answer tail- enders under any circumstances, while other rare stations are virtually impossible to work by any other method.

Hobby -Type License Denied. On July 7, 1965, the Federal Communications Corn - mission denied the International Crystal Company's petition for the issuance of a no- examination, 10 -watt "hobby" license for operation in the 29 -mc. amateur band. The Commission pointed out that issuing an amateur license without requiring the applicant to demonstrate both his ability to send and receive the Morse code and his technical qualifications would contravene article 41 of the International Radio Regula- tions (Geneva, 1959).

To make its policy unmistakably clear, the Commission further declared: "Even if examinations were not required by international regulations, the Commision would, as a matter of policy, impose such a requirement as being consistent with, and necessary to, the purposes for which the Amateur Radio Service was established."

Once again, the Commission strongly urges Citizens Radio Service operators who wish to operate radio as an activity in and of itself to obtain a license in the Amateur Radio Service. The agency points out the ease with which a Novice license (which offers its holder the opportunity to obtain the experience necessary for advancement to higher class licenses) can be obtained.

Incidentally, in a hard -to- explain maneu- ver, the FCC reduced its estimate of the number of valid amateur licenses in exist- ence by 15,000. At the same time, 75,000 were chopped off the CB totals! Possibly someone was counting renewals as new licenses.

From the Club Bulletins. In its special YL issue, SIRAN (South India Radio Am- ateur Newsletter) reports that there are four licensed women amateurs among In- dia's 400 amateurs. It also reports 26 in Australia, and 200 in Germany. And in the USSR, 10% of the amateurs are YL's.

In the Denver Radio Club's Round Table, Elsie White, wife of KOCNV, takes a dim view of the amateur's use of the term "XYL" instead of the word "wife." The practice doesn't save time. On CW, "wife" contains 10 dots and dashes (only three of them dashes), while "XYL" contains 12


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Housed is a meter case, :omponents can be conveniently mounted on two 7- terminal solder -lug strips.

TONAL DARKROOM

TIMER OR

METRONOME By FREDERICK W. CHESSON

Adjust tone and timing to your specific needs

HERE "S A NEAT little timer that will provide pleasant- sounding musical

tones in your darkroom at one -second intervals. Not only will it eliminate the tedium of making prints to a monoto- nous- sounding, mechanical -clacking type timer, but it will also give you better print control, as its staccato tones are right on the button. Transistor -operated and small enough to fit in any available space, the timer easily converts to a metronome.

How It Works. A unijunction transistor (QZ) in a relaxation oscillator circuit triggers a phase -shift audio oscillator (Q2) , turning it on and off. As capacitor Cl is charged through RI and R2, the emitter voltage of Q1 rises toward the supply voltage. When the emitter volt-

November, 1965 95

A unijunction transistor (Q1), connected as a relaxation oscillator,

triggers phase shift oscillator Q2, which generates the audio tones.

Changing the values of one or more components in the Ql circuit

alters the rate of tone burst, and changing the values of one or

more components in the phase shift oscillator alters the tone.

RI 10K

age becomes sufficiently positive, the emitter becomes forward -biased, and discharges Cl through the emitter and BI junction and R3. The voltage drop across R3 forward- biases Q2 and turns it "on." As Cl becomes discharged, the current through R3 drops, and Q2 shuts "off."

The tone signal is generated by Q2 and the phase shift components (R6, R7, C2, C3, and C4) . The signal taken from the collector of Q2 is coupled to a small speaker through Ti. The value of 18,000 ohms for resistor R4 represents a com- promise between tone duration and in- tensity ; you can substitute resistors with values between 10,000 and 25,000 ohms for different output signals.

Since the unijunction transistor is the oscillator trigger, changing the values of one or more components in the QI circuit (Rl, R3, R3 and CI) will change the rate of the tone burst. The frequency of the tone can be changed by changing the value of one or more components in the phase shift network.

Construction. A universal meter case makes an ideal container for the timer, as it easily accommodates a small speaker in place of a meter as well as the other circuit components. Potentiometer Rl and switch Si are mounted in the holes normally used for the meter feed - through terminals. Copper screening is used to cover the speaker.

The small components can be mounted in any convenient manner, such as on a

PARTS LIST B1 -9 -volt battery C1- 100 -sf., 25 -volt electrolytic capacitor C2, C3, C4- 0.05 -µj., 100 -volt miniature Mylar

capacitor C5 -0.05 to 0.25 af., 100 -volt capacitor see

text Q1- 2X1671 unijunction transistor Q2- 2X3391 transistor R1-10,000-ohm potrufionrcler R2, R4-18,000-ohm, ! _ -watt resistor R3, R6, R7- 1000-ohm, /. -watt resistor R5- 12,000 -ohm. !,-watt resistor S1- S.p.s.t. SW itch Tl-Miniature output transformer, 500 omens to

3 or 8 ohms /Lafayette TR116 or equivalent) .SP R- dliniature speakrr, 3 or 8 ohms /llisc.- L'niver.sul meter case, 7- terminal strips

(2), screen mesh, wire, solder, etc.

couple of solder -lug terminal strips, with one strip carrying the phase -shift components and the second one the transistors and other components. The miniature output transformer case is soldered to a ground lug on the latter terminal strip, and the battery is fastened to the inside of the case with a U- shaped aluminum strap.

Calibration and Use. The primary winding of Ti can be tuned for a slight increase in output; capacitor values between 0.05 and 0.25 pl. can be tried for C5. Tone pulses should begin about 10 seconds after the unit is turned on. After a minute or so, adjust R1 for one -second beats by comparing the timing of the beats with the sweep second hand on your wristwatch. 30


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New Ideas For Christmas Giving A Gift Everyone Wants . . . New Heathkit 10 -Band Transistor Portable! Travel The Airwaves Of The World . . with this new "go anywhere" 10 -band portable. 7 bands tune 2 -22.5 mc shortwave, marine and amateur stations. Longwave (150 -400 kc) receives aircraft and marine broadcasts. 88 -108 mc brings you the relaxed listening of FM. And the 550 -1600 kc AM band keeps you posted on the latest news, weather and sports. 16 Transistors, 6 diodes, 44 Prebuilt & Aligned RF Circuits ... your assurance of instant operation, superior performance and easy, 10 -hour assembly. Two separate AM & FM tuners are preassembled & aligned, ready to drop into place. FM tuner and IF strip are same components used in deluxe Heathkit FM stereo gear for the finest FM ever heard in a portable! Two Built -In Antennas . a large ferrite rod in the carrying handle for AM and longwave, plus a 5' tele- scoping whip for FM and longwave. More Deluxe Operating Features . like the battery - saver switch that cuts battery drain up to 35% for indoor listening, or provides full power for strong, outdoor reception; rotating tuning dial; nighttime dial light; 4 simple controls for tuning, volume, tone, AFC and band switching; 4" x 6" PM speaker; earphone & built -in jack; time zone map and "listener's guide." Runs on 6 "D" and 1 "C" flashlight batteries (not included). Also operates on 117 v. AC as it "float" charges batteries with optional converter /charger, GRA -43 -1 $6.95, 17 lbs.

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ASSIST Through this column we try to make it possible for readers needing information on outdated, obscure, and unusual radio - electronics gear to get help from other P.E. readers. Here's how it works: Check the list below. If you can help anyone with a schematic or other information, write him directly -he'll appreciate it. If you need help, send a postcard to Operation Assist, POPULAR ELECTRONICS, One Park Avenue, New York, N.Y. 10016. Give maker's name, model number, year of manufacture, bands covered, tubes used, etc. State specifically what you want, i.e., schematic, source for parts, etc. Be sure to print or type everything legibly, including your name and address. Because we get so many inquiries, none of them can be acknowledged. POPULAR ELECTRONICS reserves the right to publish only those items not available from normal sources.

SCHEMATIC DIAGRAMS GE Model 260 receiver, circa 1940. Tunes BC and 5 s.w. bands. Has 6 tubes. (David Worby, R.R. #2, Box 4. Hartland. Wis. I

Motorola Model WR4 record player, circa 1945. (Charles A. Stuart. 5 Main St., Marstons Mills, Mass. 02648) E.H. Scott receiver, ser. 2952. Tunes .55 mc. -16.5 mc. on 3 bands. Has 11 tubes. (Marion Faris, Peconic Trlr. Park, Box B3, Riverhead, N. Y. 11901) Philco Model 46 -350 receiver. Tunes BC. Has 6 tubes. (Chuck Schwark, 1852 W. Lake Ave., Glenview, Ill. 60025) Triumph Model 830 oscillograph wobbulator. Has 7 tubes. (Stanton N. Drummond, 152 N. Crescent Drive, Rome, N. Y. 13440) E.H. Scott "Phantom" FM receiver, ser. TT398, circa 1940. I A. Viljoen, 22 Strathbogie, 8 Caroline St., Hill - brow, Johannesburg, S. Africa) Phileo Model 38 -4 receiver, code 121, circa 1947. Tunes BC and s.w. on 2 bands. Has 8 tubes. (John Pensock, 2620 Glenview Rd., Wilmette, Ill. 60091) Boulogne -Billancourt receiver, ser. 587. Tunes 15- 2000 meters. (John W. Vogel, P.O. Box 7, Hudgins Mathews Co. , Va. 23076) RMA "Phonochord" receiver. Tunes BC and s.w. Has 10 tubes, field coil speaker, and magic eye. ( Steve Randolph, Box 330 -A, Fairhill Rd., R.D. #4, Sewickley, Pa. 1

Springfield walkie- talkie 2 -meter radiophone, circa 1957. (John 94619)

Schroeder, 4272 Atlas Ave., Oakland, Calif.

Westinghouse Model WR210 receiver, ser. 541970. Coronado receiver, ser. 344068. (David E. Halbakken, P.O. Box 615, Fertile, Minn. 56540) Superior Model 1230 signal generator, circa 1945. Tunes 7 r.f. bands and 5 a.f. bands. Has 3 tubes. (Paul Rutter, 200 W. South St., Angola, Ind. 46703) Sansei "Zephyr" hi -fi receiver. Tunes AM and FM. Has 6 tubes and 2 diodes. (Emil Albertini, Box 242, McDonald, Pa. 15057) R- 2A /ARR -3 surplus receiver, NXsa -66738, 1149:CFF, circa 1940. Has 13 tubes and magic eye. (K.A. Fulton, 754 N. Clementine, Anaheim, Calif. 92805) Browning Model 35 receiver. Tunes 1.5 -22 mc. Has 8 tubes and 6E5 tuning eye. (Joseph Patrick, Box 104, R.D. #4, Finleyville, Pa.)



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element beam that re -forms the 5 watts output power from your transceiver and tunnels it

in a "ray -like" path close to the ground to deliver you power equivalent to what you'd get from a CB rig with output power as high as 120 watts. That's "Talk Power." The Duo -beam 10 is rugged, too...all heavy gauge aluminum construction with iridite treated hardware.. -

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93 Watts TALK POWER... DUO -BEAM 6- Another new rotatable Duo - Beam by Hy- Gain...twin- driven 6 element model that delivers 93 watts "Talk Power." Guaranteed to outperform any legal CB antenna other than' the Duo -Beam 10. Model 116DB ...$69.95 Net

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November, 1965 CIRCLE NO. 20 ON READER SERVICE PAGE 101

Why Fred got a better job ... I laughed when Fred Williams, my old high school buddy and fellow worker, told me he was taking a Cleveland Institute Home Study course in electronics. But when our boss made him Senior Electronic Tech- nician, it made me stop and think. Sure I'm glad Fred got the break ... but why him ... and not me? What's he got that I don't. There was only one answer ... his Cleveland Institute Diploma and his First. Class FCC License!

After congratulating Fred on his promotion, I asked him what gives. "I'm going to turn $15 into $15,000," he said. "My tuition at Cleveland Institute was only $15 a month. But. my new job pays me $15 u week more ... that's $780 more a year! In

102

twenty years ... even if I don't get another penny increase ... I will have earned $15,600 more! It's that simple. I have a plan ... and it works!"

What a return on his investment! Fred should have been elected most likely to succeed ... he's on the right track. So am I now. I sent for my three free books a couple of months ago, and I'm well on my way to Fred's level. How about you? Will you be ready like Fred was when opportunity knocks? Take my advice and carefully read the important information on the opposite page. Then check your area of most interest on the postage -free reply card and drop it in the mail today. Find out how you can move up in electronics too.

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The "right" course for your career Cleveland Institute offers not one, but five different and up -to -date Electronics Home Study Programs. Look them over. Pick the one that is "right" for you. Then mark your selection on the reply card and send it to us. In a few days you will have complete details .. .

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.1. Electronics Technology A comprehensive program covering Automation, Com- munications, Computers, In- dustrial Controls, Television, Transistors, and preparation for a 1st Class FCC License.

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5. Industrial Electronics & Automation This exciting program includes many important subjects such as Computers, Electronic Heating and Welding, Industrial Controls, Servomechanisms, and Solid State Devices.

CIE

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Cleveland

An FCC License ... or your money back! In addition to providing you with comprehensive training in the area indicated, programs 1, 2, 3, and 4 will prepare you for a Commercial FCC License. In fact, we're so certain of their effectiveness, we make this exclusive offer:

The training programs described will prepare you for the FCC License specified. Should you fail to pass the FCC examination after completing the course, we will refund all tuition payments. You get an FCC License ... or your money back!

CIEs AUTO-PROGRAMMED lessons help you

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Cleveland Institute uses the new programmed learning approach. Our AUTO -PROGRAMMED* lessons present facts and concepts in small, easy -to-understand bits ... reinforce them with clear explanations and examples. Students learn more thoroughly and faster through this modern, simplified method. You, too, will absorb .. .

retain . . . advance at your own pace. TRADEMARK

Free nationwide job placement service ... for life, for every CIE graduate Once enrolled with CIE, you will get a bi- monthly listing of the many high -paying interesting jobs available with top companies throughout the country. Many Cleveland Institute students and graduates hold such jobs with leading companies like these: American Air- lines, American Telephone and Telegraph, General Electric, General Telephone and Electronics, IBM, Motorola, North American Aviation, New York Cen- tral Railroad, Raytheon, RCA and Westinghouse.

Electronics is a fast moving, dynamic industry ...Cleveland Institute keeps you current The Electron Bulletin is CIE's bi- monthly digest of new developments in the world's fastest growing industry. As a CIE student, you will get a free copy throughout your training to keep you up -to -date on Masers, Lasers, Solid State Devices, and other new inventions.

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Cleveland Institute of Electronics is accredited by the Accrediting Commission of the National Home Study Council. You can be assured of competent electronics training by a staff of skilled electronics instructors.

Your Future In Electronics Is Up To You. Make It A Brighter One.

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Institute of Electronics 1776 East 17th Street, Dept PE -34, Cleveland, Ohio 44114

November, 1965 105

ASSIST (Continued from page 100)

DuMont Model 274 -A oscillograph, ser. 932. Has 5 tubes and CRT. (Dennis F. Konicky, 200 Yancey St., Fort Walton Beach, Fla. 32548) Oxford Model CT400 capacitor analyzer. (B. J. White, 29 -8 Garden Circle, Waltham. Mass.) E. H. Scott receiver, ser. M -559. Tunes on 4 bands. Has 23 tubes. (Ralph Armstrong, 314 W. Santa Ana St., Ojai, Calif. 93023) R4 /ARR2 surplus receiver, circa 1953. Tunes 34 -58 mc. Has 9001's and a 12A6. (Tom Brown. 458 Randolph. Pomona, Calif. 91766) Fisher Model T -20, T -30 metal detector. Detectron Model 7 -T metal detector. Goldak Model 520 -B metal detector. (Roland Earl, 11311 Hunnewell, San Fernan- do, Calif.) Hickok Model 560 mutual conductance tube tester. (Jim Hallock, Jr., Tilden, Ill. 622921 GE (Canada) Model F -62 receiver, ser. 0767, circa 1936. Tunes 530 -1720 kc., 2.1 -22 mc.. on 3 hands. Has 6 tubes. (Lynn Green, Rt. 6, Box 86, Birmingham. Ala. 35217) Superior Model 450 -A tube tester. (Charles R. Mueller. Box 8, Keyesport, Ill.) Detrola Model 700 17" TV, circa 1951. Has 18 tubes. (John Baron, 5752 Renville St.. Detroit. Mich. 182101

SPECIAL DATA OR PARTS

Philco Model 42 -350 receiver. 121, circa 1912; tunes BC, s.w., FM; has 7 tuba Schematic and parts source needed. (David Jones, 1,11 Edison Dr., San Antonio, Tex.) RCA Model 46X13 receiver. Schematic and ballast tube M- 86289 -9 needed. (R. A. Spinney, 50 Pond St., Billerica, Mass. 01821)

Wards "Airline" Model 6D4 -1 receiver, ser. ó -D4- 904488; tunes BC and s.w. Schematic, dial and pointer needed. (Steve Hallberg, Box 184, Center City, Minn.) Perkin Elmer Model 012 -0110 densitometer, ser. 151. Schematic, operating instructions, and input device with connecting cable needed. (Arnold Walter. 155 Bathurst Dr., Tonawanda, N.Y. 141511

Patterson receiver, circa 1938; tunes 550 kc.- -18 mc. on :i hands; has 12 tubes. Schematic and tube layout needed. (Christopher Coles, 1033 Alta Pine Dr., Alta - (Iena, Calif. 91001)

Heath Model MP -11 marine converter -charger. Kit assembly manual needed. (R. J. Stephenson. P.O. Box 1123, Chattanooga, Tenn. )

Sanyo Electric Model 8SP1-1 receiver; has 8 transistors. Schematic and tuning meter needed. (E. Metz, 4620 N. Kenneth, Chicago, Ill. 60630) Stromberg Carlson Model RBS receiver, circa 1940; tunes 2 -20 mc. Schematic and alignment instructions needed. (Wayne K. Irwin, R.F.D. =1, Mt. Spring Rd., Rockville, Conn. 06066(

Philco Ain,Iel 8211 receiver: tunes 530 -170(( Oc., and 2.3 -22 mc. ; nits 6 tubes. Schematic tuner coils. switch, and other parts needed. ¡Lance Muller, 8895 Halsted St.. San Diego, Calif. 92123) Grunow Model 1067 receiver, chassis ä10D; tunes .54 to 15.4 me on 3 bands; has 10 tubes. Schematic, service data, and source for parts needed. Richard Neubert.

60 Balch Ave., Manchester, N.H. 03102¡ Hallicrafters S -20R receiver. series H- 144011; tunes .51 -40 mc. Schematic and accessory socket data needed. ¡Michael Ramaccia, 1 Wind Pl., Whiteshoro, N.Y. 13492¡ Philco Model 37 -670 receiver, circa 1936; tunes BC and

- has 11 tubes. Tuning dial ¡Philco Part No. 52131 needed. (Steve Shapiro, 2512 Princeton Rd.,

('Ieveland. Ohio 41118) RCA Model 813K receiver, circa 1928; tunes BC and S.W. ; has 13 tubes. First i.f. transformer needed. (Paul Songer. 2925 NE 45th Ave., Portland, Ore. 972131

Hazeltine "Air Castle" receiver, chassis =521, ser. 313115; tunes AM and s.w. Schematic and power transformer needed. (Bill Cruse, Box 630. Mooresville, N.C. 2,5115)

Fada Model C 69 A receiver. ser. 1704: has 5 tubes. Battery voltages needed. (James Pyles. 16 Dobson Rd.. East Brunswick, N.J.) Midwest receiver, circa 1933; tunes 155 kc. -32 mc. on 5 bands; lias 16 tubes. Schematic and other data needed. (Johnny Simmons, 2953 Crestline, Macon, Ga. 31204)

Philmore Model 100 -1 receiver; tunes BC haul; has 5 tubes. Schematic and alignment data needed. (Et- hridge W. Smith, 5 N. Grandview Terr.. Cobleskill, N.Y. 12043 )

Belmont Radio Model BC- 1161 -A receiver, circa 1940: tunes 150 -210 mc.; has 13 tubes. Schematic, alignment data, and operating manual needed. (J. Laine. 807 E. St., Dedham, Mass. 02026)

RCA "Radiola 46" Model AR -596 receiver. Tuner section framework and tuning capacitor needed. (Ray Lowe, Route 1, Box 44 -B, Wilkesboro, N.C. I

Presto record head control disc cutter amplifier; has 11 tubes. Schematic and other (data needed. (Malcolm Tharden, 6202 Ruatan St., Berwyn Heights. Md. 207411

GE Model 16C103 TV set, circa 1951. Deflection yoke needed. (Gary J. Schlager, 54 Barbara Pl., Cheek- towaga, N.Y. 142251

Admiral Model 4H18 phonograph, TV and AM -FM re- c -fiver. Service info. and other available data wanted. (Jay Hans, 22 Sparrow Circle, White Plains. N.Y. 106051

Zenith "Trans- Oceanic" receiver; tunes 550 he --18 mc. on 6 bands; has 8 tubes. Schematic, operating instructions, and battery info. needed. (Stanley .Tones, Box 488, Hollandale, Miss. 38748) Federal "Orthosonic" receiver, type E, ser. 292795; tunes BC; has 6 OlA tubes. Schematic and info. on hooking up batteries needed. ( V.E. Lingblooni, Elsie, Nebr. 69134)

Supreme Model 501 -A tester. Parts list, schematic. and operating manual needed. (Thomas P. Meehan, 1109 Laurel Ave., E. Palo Alto, Calif.)

Pre-tuned/pre-packaged IF strip Model 8902 pre -tuned 455 KC IF strip provides excellent gain (55 db) and selectivity (6 db bandwith: 8 KC), No alignment is required. Included among the 21 components on the PC board 'are a mechanical filter, 2 transistor amplifiers and a diode detector capable of driving earphones. Overall dimensions: %" x %" x 1 % ".

Model 8901 input I F transformer adapts the I F strip for use with a converter in capacity detectors, AM and CB receivers. Both units are included for $5.75 net.

J. W. MILLER COMPANY NOW ON DISTRIBUTOR SHELVES 5917 SO. MAIN STREET LOS ANGELES, CALIFORNIA 90003

CIRCLE NO. 28 ON READER SERVICE PAGE 106 POPULAR ELECTRONICS

Five new features and fine new performance for the saw d $9$.95

Our original Pacer is a fine CB transceiver. But our new Pacer II is even finer! Pacer Il not only gives you all the features that

made our original Pacer such a bargain (23- channel tunable superhet receiver, positive squelch control, quick- change external crystal socket), it now offers new, smaller case, plus a built -in, solid- state, 12 -volt power supply, plus 11 (not just eight) crystal -controlled channels, plus an ANL switch and a big, easier -to -read "S" meter.

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Better look into a new 1966 model Pacer II today. Complete with channel 11 crystal, PIT mike. mobile mounting bracket. carrying handle, AC and 12V DC power supply cords $99 95

ALSO NEW MUSTANG II

November, 1965

Get on the air for just $79.95 and get these new Mustang Il features: eight crystal -controlled (not just six) channels, quick- change external crystal socket, "S" meter,

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't

AT YOUR NEWSSTAND ON NOVEMBER 18

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This solid -state HO train controller will add that sought -after feature -the "crawl." Ends jerky starts and operates smoothly in either forward or reverse. Build in 6 -8 hours.

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Now with exclusive new

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OPERATING FEATURES AND PERFORMANCE THAT MAKE YOU PROUD TO OWN THE BEST!

C b ra23 CHANNEL FULLY - EQUIPPED AM CB TRANSCEIVER

Other Features include: Transistorized 117 VAC /12 VDC

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Standby Switch Illuminated S and RF OUTPUT Meter Modulation Indicator Plug -in Microphone Use as Public Address Amplifier

See your B &K Communications Distributor for demonstration or MAIL COUPON TODAY

CIRCLE NO. November, 1965

Here is talk -power you'll be glad to talk about! Full 5 watts input plus built -in speech compression Dyne - Boost circuit that puts the power in the sidebands where it does the most good. Increases modulation level to the very maximum at all times, even for a soft woman's voice. Front panel switch enables you to use Dyna -Boost as you need it. Make the dramatic "talk - test" and prove it for yourself! Fully equipped with all necessary crystals for immediate operation on all 23 CB channels, at a turn of the switch. COBRA CAM -88, $214.95 r

11 P5 B &K MANUFACTURING CO. DIVISION OF DYNASCAN CORPORATION 1801 W. Belle Plaine, Chicago, III. 60613

Please send informative COBRA Bulletin 643.P

Name

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City State Zip No 51 ON READER SERVICE PAGE

109

Super -Sens

(Continued from page 62)

(ARM and either N.O. or N.C. contacts) are connected to switch an appropriate solenoid valve in the automatic sprinkler system.

Either the low- resistance connections or high- resistance connections can be used, depending on soil conductivity, electrode (probe) spacing, and desired soil moisture content. In any case, the instrument's Sensitivity control can be finely adjusted to achieve the desired operating characteristics.

Acoustic Relays. Add an easily -built, low -cost accessory, and Super -Sens becomes a sound -operated relay. Three types of circuits are shown in Fig. 9.

In Fig. 9 (A), a low- impedance single - button carbon microphone (Shure R10) ,

a 6 -volt battery, an 8 -ohm to 500 -ohm output transformer (Argonne AR -164), a 1N34Á general -purpose diode, and a 2 -µf., 15 -volt electrolytic capacitor apply a positive -going signal to energize the relay.

A single- transistor amplifier, in Fig. 9 (B) , enables the use of a high- imped- ance (Philmore M -55), or a low- imped- ance carbon microphone. A 1- megohm resistor (RI) is used with high- imped- ance microphones and a 47,000 -ohm resistor for low impedance types. The Sen- sitivity control is adjusted until the relay

,I

Fig. 10. Radio control can be achieved with simple detector. Tune Cl, Ll to desired frequency.

closes and is then backed off slightly. Thereafter, a sudden sharp sound will cause the relay to "latch" open.

A crystal microphone cartridge, or a magnetic headphone element can be used as a microphone with the circuit shown in Fig. 9 (C). The diode and transistor are the same as in the previous circuits. The Sensitivity control is set in the same manner as in the circuit in Fig. 9 (B).

The acoustic relay circuits shown here are moderately sensitive, requiring a fairly loud signal for operation. Where extreme sensitivity is needed, Super - Sens can be coupled to a 3- or 4- transistor audio amplifier. The hookup would be the same as in Fig. 9 (A) .

Radio Control. Super -Sens can be operated by remote radio signals provided that a suitable control circuit is con-

Fig. 9. Sound -actuated relays can be made. If microphone is low -impedance type, use circuit (A); high- impedance pickups work well in circuit (C); a low- or high -impedance unit can be used in circuit (B).


nected to its input terminals, as shown in Fig. 10.

The values of tuned circuit Ll and Cl are chosen to resonate at the desired control frequency. A general -purpose diode (1N34A) and an npn transistor (2N169) can be used. Adjust the Sensi- tivity control until the relay just closes in the absence of the radio signal. An incoming radio signal will open the relay.

Bench tests with the remote control circuit were made using a standard AM broadcast -band ferrite -core antenna coil (Superex "Vari- Loopstick ") for L1 and a 270 -pf. ceramic capacitor for Cl. With a relatively short antenna, positive relay operation was obtained when a strong local broadcast station was tuned in.

Photocells of all types can be used with Super -Sens to make it respond to variations in illumination and color. In- visible infrared rays can be used as in- truder alarms. Smoke detectors and industrial counting devices can also be made. Regardless of the intended application, whether specific or general, the only limit to Super -Sens is your imagination and skill. - 300-

6 -WATT AMPLIFIER (Continued from page 75)

signal source and amplifier input as shown in Fig. 1. Although a 1- megohm pot is shown, values of 100,000 or 500,000 ohms can be used.

If plans call for the amplifier to be employed with a low- impedance input device, say about 1000 ohms, reduce the value of R4 -or even eliminate it. This will give you a substantial increase in gain. There's no point in reducing the value of R4 for a high -impedance input, as no appreciable gain will be realized. A 150 -ohm resistor placed in series with C2 introduces negative feedback, and lowers the output impedance still more, and reduces distortion, but sacrifices gain. The higher the resistance, the greater the feedback and the lower the gain.

The amplifier's high- frequency response can be substantially improved by substituting 2N2148 transistors for the 2N554's in the output stage. They cost

November, 1965 111

GIANT NEW CATALOG

100's OF BIG P GES CRAMMED WITH SAVINGS

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I E Rush me FREE 1966 B -A Catalog.

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So what else is new?

THE BROWNING RAVEN CB MOBILE UNIT!

Transmitter has: 100% peak limited plate modulation. Opto- electronic automatic compressor.

Receiver has: Sensitivity 0.2 uy for 10 db of quieting. Adjacent channel rejection 80 db down.

Pius: Two Nuvistor cascade front end. All 23-channel crystal control transmit and receive. No synthesized circuits. Twelve tubes (19 functions); two transistors and five diodes. Luxury appearance. Covered with black vinyl in leatherette finish. Truly compact. Only 4" high by 103/4 " wide by 8" deep.

See the Raven at your franchised Browning Service Center now or write for complete literature and specifications.

Lrownin_ _ LABORATORIES, INC.

DEPT. PE -11, 1269 UNION AVENUE, LACONIA, NEW HAMPSHIRE 03246


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112

BIAS NETWORK

A closer look at the biasing arrangement of the various transistors in the Six- 1Catter is needed for a better understanding of how the circuit operates and how balanced operation can be achieved even if the d.c. current gain of the transistors differs.

Resistors RI and R2 maintain the bias voltage at the base of QI at approximately one -half the 5111)1)13' voltage. If the voltage at point A in Fig. 1

drops, the potential difference across Q1's base - emitter junction increases and causes QI to conduct more heavily. The greater current flow through R3 increases the voltage drop across R3, and increases the forward bias of Q2. This makes 02 conduct more heavily and increases the for - Ward bias on 03 and Q5, at the same time decreasing the forward bias on Q4 and Q6.

Transistors Q5 and 06 act like a voltage divider across the power supply, and the biasing action just described reduces the dynamic resistance of 05, and increases the dynamic resistance of Q6. This raises the voltage at point A and tends to restore it tu its former value.

li, on the other hand, the voltage at point :1 rises above normal, the forward bias on Q2 dc- creases, reducing the bias on Q3 and 05,increasing the bias on Q4 and Q6, increasing the dynamic resistance of Q5, decreasing the dynamic resistance of Q4, and, finally, decreasing the voltage at point A to its normal value.

Diode D1 also affects the bias of Q3 and Q4. The voltage drop across Dl places a small forward bias on Q3 and 04. which in turn places a small forward bias on Q5 and Q6. This forward bias reduces crossover distortion and serves to thermally stabilize the amplifier. Changes in voltage drop across the diode due to changes in temperature tend to compensate for similar temperature changes in the base -to- emitter voltages of the transistors. The voltage drop across Dl is essentially independent of supply voltage and therefore is able to maintain the same bias over a relatively wide range of supply voltage.

about $1 more each; the 2N554's were used because of their low cost. Should you decide to substitute "bargain" transistors for Q5 and Q6, you may run into higher than normal leakage currents. To overcome this situation, you can connect a 100 -ohm, 1A -watt resistor between the base and emitter of Q5 on the bottom side of the board.

If you plan to use the Six -Watter as a narrow -band speech amplifier, reduce the value of C2 and place a small capacitor in parallel with R5 to cut the amplifier's response at both the high and low ends.

The amplifier can also be used as a modulator for small transmitters. An ordinary output transformer connected backwards makes a reasonably good match as a modulation transformer. Use an output transformer which can match the impedance of the final stage of your transmitter to the amplifier's nominal 3.2 -ohm load. -[p}

POPULAR ELECTRONICS

HI -FI STEREO FOR '66 (Continued from page 51 )

AM tuner, in addition to the usual FM /FM multiplex. Allied Radio has added the KG -964 to its Knight -Kit line with 34 wpc and with a price tag of $189.95.

In the wholely -wired up line and ready to go are such units as the Harman -Kar- don "Stratophonic Series" ranging from 18 to 33 wpc and price tags of $279 to $469. Scott's latest entry in this field is the elegant 388 marketed at just under $500; the 388 appears to be the first receiver using field -effect transistors to virtually eliminate all FM cross - modulation effects. Fisher's latest word is the husky 600T rated at 55 wpc and 1.8 microvolts of FM receiver sensitivity ; it's tagged at $459.50. The Bogen line offers the new RT8000 for $319.95 and 35 wpc. For sleekness, try the Elec- tro -Voice 1177 with 25 wpc which sells for only $280.

Other Equipment. Transistors have invaded tape recorders in style, but a report on these units will appear in a separate article scheduled for the Decem- ber issue of POPULAR ELECTRONICS. You can also find solid -state devices in other odd corners, such as the Shure SA -1 "Solo- Phone" ; this small amplifier can be connected to either tape or phono and used to drive two sets of stereo head- phones.

Regardless of where you find them - transistors are in hi -fi /stereo to stay. Vale tubes.

25-50 me 37 WATTS

FCC TYPE ACCEPTED

HOW TO STACK TV ANTENNAS (Continued from page 65)

Fortunately, this is quite simple. All you have to do is vary the horizontal spacing between the antennas. And you don't need any complicated formulas or measurements, either. The trial and error method works best.

Before you start shifting the antennas, you should construct a symmetrical harness -same type leads, lengths, and matching transformers -between the hybrid splitter and the antennas.

Point both antennas directly at the transmitter. Keeping them parallel, slowly move one antenna closer to, or away from, the other. While you are doing this, you need someone to watch the TV set for a sudden, sharp reduction in the unwanted signal. Secure the antenna in this position. The unwanted signal may still be noticeable in spite of the sharp reduction. But, you're not through yet.

Remember that the unwanted signal must appear as equal and opposite polarity voltages to cancel out. By finding the correct horizontal spacing, you've made sure that the unwanted signal arrives at the two antennas 180° out -of- phase. Now, you must make sure the signals are equal. To do this, simply move one antenna up and down on the mast while someone again watches the screen. Secure the antenna at the point where the unwanted signal is weakest.

Horizontal stacking is used to clean up master TV antenna systems, and it works just as well in home TV installations - especially color installations. -1W

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114

SOLID STATE (Continued from page 80)

distortion for, as we discussed last month, even -order harmonics are cancelled out in a push -pull stage.

Unfortunately, the push -pull circuit can also introduce an undesirable amount of intermodulation distortion due to the non - linearity of the composite transistor characteristics. The remedy, here, is to use matched transistor pairs in the push -pull stage, and then operate the stage Class A or Class AB to insure a smooth crossover point.

In summary, to minimize all types of distortion in your transistor audio amplifier:

(1) Adjust individual stage bias values for operation within the transistor's linear region, biasing single -ended stages Class A, and push -pull stages Class A or AB. Avoid the use of Class B stages.

(2) Make sure that no stage is overdriven. (3) In push -pull circuits, use only tran-

sistors with matched gain and leakage characteristics.

(4) Make sure that iron -core transformers are operated within their d.c. ratings to avoid saturation.

(5) Use good -quality coupling capacitors to avoid interstage leakage.

(6) Use inverse feedback where appropriate.

Product News. The Clarostat Manufac- turing Company (Dover, N.H.) has just announced a new low -cost trimmer potentiometer. Ideal for miniature transistor circuits, the unit is only l/" in diameter by l', -;" deep. It is designed for screwdriver adjustment, is

available in standard resistance values from 100 ohms to 1 megohm, and has a power rating of 1/4 watt.

A new line of extremely high gain Dar- lington pair transistors, packaged in single cases, has been introduced by the Solid State Electronics Corp. (15321 Rayen St., Se- pulveda, Calif.). The first device in the line, the SST610, offers a current gain of 10,000 with an output current of 120 ma. Future units will have a gain of up to 100,000 or more, according to the manufacturer.

The development by General Electric's Semiconductor Products Department of a

POPULAR ELECTRONICS

new continuous -strip manufacturing process should result in more low -cost SCR's for consumer products. The first units produced with the new process are 150 -watt, 117 -volt types; later units will have ratings of up to 2 kw. or more. Initially the new SCR's will be used in motor control circuits of such appliances as food mixers and sew- ing machines.

Well, the Holiday Season is approaching; now is a good time to start assembling transistorized gifts for your friends. Until next month ... -Lou

MATH QUIZ ANSWERS

(Quiz appears on page 67)

1 - H Amplifiers which have their load resistors in series produce an output signal proportional to the sum of the in -phase input signals.

2 - F A step counter produces an escalated output which varies exponentially with the number of pulses it receives. It can be used to count the number of pulses it receives, and as a frequency divider by allowing it to trigger another circuit, say at every 2nd. 3rd ... 7th step, as desired.

3 - I A differentiator circuit produces an output whose instantaneous values are proportional to the rate of change of the input voltage waveform.

4 - G A voltage doubler produces a d.c. output which is approximately equal to twice the r.m.s. value of the a.c. input voltage.

5 - D A voltage divider provides an output which is in the same proportion to the applied voltage as the divider resistance is to the total resistance.

6 - A An integrating circuit provides an output voltage which is approximately proportional to the time integral and potential of the input voltage.

7 - J In a ratio detector circuit, the variations of audio frequency output signals have the same ratio as the variations of the applied FM radio frequency signals.

8 - C A triode square law detector produces an output signal which is proportional to the square of the input signal.

9 - E A differential amplifier produces an output signal whose amplitude is proportional to the difference between two in -phase input signals.

10 - B A voltage tripler circuit produces a

d.c. output which is approximately equal to three times the r.m.s. value of the a.c. input voltage.

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PARTS PROFILES (Continued from page 77)

connected directly across the power line, so don't take chances. You must use a polarized plug or a nonmetallic case. Input and output connections that could be touched accidentally must be transformer -coupled, unless you are using a power isolation transformer. A low -cost 25 -watt unit will more than suffice since filament power is no longer needed.

Figure 4 shows a line- operated half -wave power supply that provides a no -load d.c. output of about 165 volts. Resistor RI is a limiting resistor that also takes care of current surges. You can use this supply as a direct replacement in any tube or selenium rectifier circuit that calls for approximately 150 volts at not more than 150 mils. The 40265 makes a dandy power supply for experiments with neon lamps.

RED DOT

0265 R0 QDC OUTPUT

AC INPUT ASV

2500 + 162V.

60CP5 aw sopt, AT Omo. Tisov ß1V

-.4. AT 125mo.

Fig. 4. Low -cost, line- operated, half -wave power supply using RCA 40265 400 -volt, 125 -ma. silicon rectifier, semiconductor equivalent of 35W4 tube.

Now let's give the 40264 the once -over. This job needs a heat sink because of its high power rating (4 watts, 300 volts). The heat sink must be insulated, or you will have to use a mica washer and silicone grease between it and the transistor. It's best to use nylon screws for insulation; if you use ordinary hardware, then use nylon bush- ings for mounting. The thing to remember is that the transistor case is at line potential and must be mounted where it cannot be touched accidentally.

Figure 5 shows the 40264 in a basic two - stage amplifier that can serve as a phonograph amplifier or be used in the audio output stage of an AM receiver. At 1/2-watt output, the distortion is only 2 %. If you don't mind 10% distortion, then you can crank it up to a full one watt of power.

The frequency response, which can be quite good, is determined by the quality of the output transformer you use. The amplifier will put out 600 milliwatts with an input of around 1/ volt into 50,000 ohms. This is usually adequate for most inputs except magnetic pickups and other extremely low -level sources.


INPUT

+162VOC TI AT 0 mo.

50L6 OUTPUT rRANSFORMER

2 MEG. POT

WARNING HOT GROUND. USE POLARIZED SOCKET, ISOLATION OR INPUT TRANSFORMER OR COMPLETELY INSULATE ENTIRE CIRCUIT

NOTE' ALL RESISTORS v2 WATT

Fig. 5. Basic line -operated solid -state amplifier delivering up to one watt of audio power at 10% distortion; at one-half watt distortion is only 2 %. Frequency response is a function of the quality of the output transformer used, but is usually good.

A data sheet, No. ICE -313, on RCA solid - state devices 40261 through 40265, is available on request from: Radio Corporation of America, Electronic Components and De- vices, Harrison, N.J. The RCA 40264 power transistor and 40265 rectifier are priced, respectively, at $1.20 and 35 cents, and are available from RCA semiconductor distributors. --

AMATEUR RADIO


dots and dashes (half of them dashes). When spoken, "XYL" contains three sylla- bles; "wife" contains one. Furthermore, Elsie complains, being called an "ex" young lady casts aspersions on her state of preser- vation, and is an insult to her intelligence and to the skill of her beauty operator. El- sie realizes, by the way, that she is fighting a lost cause.

As reported in the June 15 issue of the DX- pedition of the Month Bulletin, John H. Gayer, HB9AEQ, honorary president of the International Amateur Radio Club, Ge- neva, Switzerland, speaking at the Second SSB Banquet in London, England, related that one of the problems plaguing amateur radio was unauthorized commercial intruders moving into the ham bands at hours

November, 1965 117

right into your tape recorder - then play it back and listen to the lively sound of your own voice - so natural, no one can tell the difference. University's new revolutionary Attaché is the smallest cardioid dynamic microphone ever made. Priced right too! Free! "Microphones '66" -a book every owner of a tape recorder should have. I) UNIVERSITY SOUND

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when amateur activity is low. From personal observation. several South or Central American commercial CW stations move into the 20 -meter amateur band almost every afternoon. But if a couple of powerful amateur stations happen to open up on the frequency usurped by the intruders, the latter soon move back where they belong - or on someone else's frequency.

News and Views Allan J. Sorkin, WN6PTT, 9115 S. Strub Ave.. Whit-

tier, Calif., operates on 80 meters using a convert- ed ARC -5 war -surplus transmitter feeding an end - fed antenna. He receives on a Knight -Kit R -55 or un a BC -454; both are helped along by a preamp and a surplus FL -30 audio filter. Allan likes b rag -chew to give himself plenty of code practice so he can get his General license as soon as possi- bl, which he plans as the next step in his campaign to earn an Extra Class license . . Arne Hen - den, WNSHMR, 1565 S. Esperanza. Las Cruces. N. \l.. reports that three out of four of the stations he works say he is their first New Mexico contact. Arne stays on 40 or 15 meters and has 4h .states worked, including three contacts with Hawaii. plus Guatemala. Canada, and the Bahamas. An Elmac A -54 transmitter pushing 40 watts into a 40 -meter dipole antenna. and a Hamnrarlund HQ- 110 receiver handle the electronic work. Arne's neighbors are in for a "thrill" soon -he is building a 40 -10 meter quad antenna and a 15- meter beam. both to go on a 40' pole . . . Dan L. Marshall, WN80E0, 1728 Sheffield Drive, Akron. Ohio, is a resourceful ham. When his Novice license arrived, he already had a Hallicrafters SX -140 receiver; but the HT -40 transmitter, which was un order. hadn't arrived. So Dan built himself a 25 -watt transmitter and knocked off five states in his first week on the air. Now, with the HT -40, he has 23 states worked. All of his operating is on 80 ureters. with an 80-meter inverted -V antenna.

All Florida High School Amateur Radio Clubs, take note. Plans are under way to organize a Flor- ida H.S. Net. Write to C. Lynn "Tank" Miller, WA4UB0, president, Hillsborough H.S.A.R.C. (WA4VQW). 309 West Lambright. Tampa. Fla., 33604, for information . Agustín O. Monasterio, XE100L, P.O. Box 41 -634, Mexico 10. D.F., Mexico. is one of the youngest of the 6000 Mexican amateurs (he is 16). In three months, running 50 watts on 20 meters, AM phone, he has worked 19 countries -all in the Americas. His transmitter is a Heathkit DX -60 feeding a 40 -, 20 -, 15 -meter inverted-V antenna, and he receives on a National NC -140. Unfortunately. Augustin has not yet been able to get the antenna to "load" on 40 ur 15 rue-

tens, but being limited to one band hasn't seemed to slow him down much . Pete Doyle, WN2OUO, 16 Woodcliff Lake Rd.. Saddle River, N.J., closed out his Novice career by working Italy the day before his license expired. Being away at school most of the time cut down Pete's on- the -air time, but he did work 13 states and a few other DX stations besides Italy with a Heathkit DX -60 transmitter and a Lafayette HE -10 receiver. Of course, Pete is now Guru, Ho after his General ticket . .

Mike Di Corpo, WNICRS, 35 Sunny Brook Bend. Waterbury, Conn., also found that school cuts down on a fellow's QSO total. Still, he made 100 contacts in 10 states and Canada with his Heathkit DX -60 transmitter in spite of a poor receiver-he now has a much better Lafayette KT- 320 receiver. And with separate dipole antennas already up for 80, 40, 20, 15, and 10 meters. Mike is ready for the arrival of his General ticket, too.

Everitt C. Rollin, WA3DVO, 2029 E. Lanvale St.. Baltimore, Md., is a radioman in the Navy stationed in Washington, D.C., following a tour of duty ,n Midway Island, where he operated as KM6CJ. In two months on the air from Baltimore, Ev's Knight -Kit T -150 transmitter, Gotham V -80 vertical antenna, 20 -meter dipole, and Hallicraft- ers SX -140 receiver have come within a state or two of a WAS (Worked All States) certificate .. .

John Wieder, WAOJYJ, RFD 1. Northboro. Iowa, likes to rag -chew on 75 -meter phone and to chase DX on 20 -meter CW. He has one transmitter -a Heathkit DX -100: two antennas -a V -40 vertical and an 80 -meter dipole; and three receivers -a Hanmaarlmui HQ -150, Heathkit GR -91, and Haiti - crafters S -85. John's brag list contains QSL cards from 13 of the 44 states worked, and all Canadian call areas, plus Puerto Rico ... Richard T. Schweizer, Jr., WB2PCF, 240 -27 -145 Ave., Rosedale, L.I., N.Y., is a duce- antenna man. They are: a Hy -Gain 14- AVS vertical: an 80 -meter inverted V: and a Hy- Gain TH -2 2- element beam. Like WAOJYJ above, he has 44 states worked and 43 QSL'ed in addition. he has all Canadian provinces and 16 countries worked. A Johnson "Ranger" transmitter and a Drake 2 -R receiver serve as the go- betweens between Dick and his antennas . Brian Kirchoff, WN6WWD, 206 Alpine St., San Rafael. Calif., had no trouble deciding which was his most thrilling contra t- American Samoa! In addition, he has 9 states worked. Brian's Heathkit DX -20 runs 50 watts to feed a 40 -meter dipole about 30' high, and he receives on a Lafayette HE -40.

Good luck in the WWDX and SS contests. Until next month, keep your "News and Views" and pictures coming; and remember, we appreciate receiving copies of your club paper. The address to use is: Herbert S. Brier, W9EGQ, Amateur Radio Editor, POPULAR ELECTRONICS, P.O. Box 678. Gary, Ind. 46401.

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ON THE CITIZENS BAND Continued from page 91)

Appropriately dubbed "Call Letter Di- rectory," the volumes list CB'ers in both alphabetical and numerical order by state. town, and licensee in each town. In addition, the directory contains Part 95 rules and amendments, the phonetic alphabet, the 10 -Code and an alphabetical listing of call -letter prefixes for all areas, and a 1960- 65 U.S. area map.

The books are put together well, are highly legible, and are a real help when you know the other party's call -sign but not his name, or vice versa. Directories are currently available for areas 6, 8, 9, 11, 12, 18W and 18E. The listings are up to date and total 13.000 to 40.000 per directory, depending upon the size of the area. Prices

range from $3.50 to $5.95. The directories will be republished annually, and other area listings will be available soon.

For all the details, drop a line to K9TVA. Dept. SS, 6429 N. Glenwood Ave., Chicago, Ill. 60626. And while you're at it. ask Mel for a copy of his illustrated brochure which lists a bundle of useful CB identification badges. decals, pins and accessories.

Club News. The Metropolitan Denver Citizens Radio Club of Denver, Colorado. has reported on their participation with authorities when a 12 -foot wal: of water

November, 1965

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heading down the South Platte River threatened Denver and the metropolitan area. Approximately 200 CB'ers responded immediately to a call for assistance in evacuating persons living along the river. Before the threat was over. more than 500 CB'ers were on hand to help where needed. Several mobile units were placed at road- blocks while others were used for transportation. Most of the CB'ers involved averaged three to four hours sleep in 24 hours; some went without sleep for two days.

The Five Watt Wonders CB Radio Club of Greater New Orleans, La.. made an all - out drive to up membership, set up a permanent 24 -hour monitoring station, and ready their group for upcoming Mardi Gras fes- tivities. The club's monitoring channel hit the air for the first time this year on Mardi Gras Day. The station handled emergency traffic for 12 hours through contact with CB mobiles stationed at six different Red Cross stations spread along the Mardi Gras parade route. New Orleans Red Cross and police officials were amazed at the swiftness with which the CB'ers handled 113 emergency requests for supplies and ambulance service during the activities.

In Fort Lauderdale. Fla.. a Mr. Richard Gaddy was so appreciative of the "fast service" he received from CB'ers in the Eleven Meters Citizens Radio Club, he decided to join them. His car was stolen early one a.m., and his main concern was that the vehicle contained a number of valuable books and papers belonging to the insurance firm that employed him. Club members spread the word throughout Broward, Dade and Palm Beach counties. Two days later CB'er Jake Moore. KKP5456. spotted the car and relayed the information to Bill Walker. KKP4058. All stood by until sheriff department deputies took over, and Mr. Gaddy's car and its contents were returned intact.

1965 OTCB Club Roster. The following are clubs reporting to On the Citizens Band for the first time. New clubs or those which have not been listed in this column in the last year should forward all details to keep our "active" CB club list current. Be sure to include number of members, when organized. primary activities, emergency assists, and special teams or groups. A picture of your group could end up on these pages -if you include it.

Anchorage, Alaska: Southcentral Alaska Chapter of MCEU, Inc. This club was organized in December, 1964. The officers are: Tom Moore, KKNO808, president: Jerry Miller, KLN9149, vice president: Tony Arm- strong, KKB3724. secretary: and Rick Croan, KLU0173, treasurer. The group was

CIRCLE NO. 25 ON READER SERVICE PAGE -ÿ

lauded by William Egan, Governor of Alas- ka, and Don Lowell, state Civil Defense director, for assistance during the Alaskan earthquake.

Vancouver, B.C., Canada: Tupper High Communications Club. Organized in Sep- tember, 1964, the group meets at the Sir Charles Tupper High School weekly. They specialize in the repair of radios and appliances for a small service charge but no dues are collected from club members. Club president is Cal Dooseman, XM11 -3033; vice president, Ging Quan; and secretary, Larry Hudson, VE7PE1AO.

National Park, New Jersey: Dvert r-B Club of National Park. Forty -three active members work closely with police and civic authority groups. The club monitors channels 9 and 13. Officers are: Carl Wilson, president; Bob Vincent, vice president; Don- na Black, secretary; and Lil Kenny, treasurer.

Other clubs reporting: In Aurora, Colo- rado, Aurora CB Radio Association; in Chicago, Illinois, Mid -America Rescue Squad of Illinois; in Silvis, Illinois, Iowa - Illinois CB Club; in Knoxville, Tennessee, Knox County 10 -4 Club, Inc.

I'll CB'ing you, -Matt, KHC2060

PREDICTED CONDITIONS


EST, and Israel on 9725 kc. from 2300 to 0030 EST; both should be audible on nights when DX conditions are good. The gigantic transmitters of the VOA from Greenville, North Carolina, should be heard over much of the country on both 9635 kc. and 9740 kc. with their English -language broadcasts.

25 Meters. East -west reception in this band is not expected to be good during the next few months. The maximum usable frequency will be too low for much DX during the daylight hours and too high for DX during the nighttime hours. Many Cen-

- tral and South American stations will be audible, however.

For DX'ers interested in transmissions from the Pacific, the VOA relay station at Colombo, Ceylon, on 11,835 kc. should occasionally be audible from 0700 to 1300 EST. Taipei, Formosa, on 11,825 kc. will also be on the air at approximately the same time. The Philippines on 11,900 kc. and 11,930 kc., as well as the BBC relay from Singapore on 11,955 kc., may be audible in the western half of the United States.

November, 1965

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19 Meters. Almost unlimited DX possi- bilities exist in this band from before sunrise until after sunset local time. Overall, the 15 -mc. band will be the best DX band at this time of year with every major foreign broadcaster, and many smaller ones, using these frequencies in daylight hours.

Of special interest will be the new British relay station on 15,310 kc. This transmitter has a power of 250,000 watts and will carry programs for West African consumption. The announced schedule says that the transmitter will be on the air at sunrise, and at 0900 is scheduled to move to 15,435 kc. and remain there until sign -off at 1730 EST.

Turkey will be a good catch from 1100 to 1600 EST on 15,195 kc. Listen also for Nigeria on 15,255 kc. with transmissions from mid -morning to mid -afternoon EST.

16 Meters. On good days in this band very strong signals should be received -even exceeding the strength of those in the 19- meter band. DX will peak in the morning and should taper off in the early afternoon. On the West Coast, DX will decrease sharply after 1000 PST.

Announced schedules show Egypt on 17,785 kc. and Switzerland on 17,795 kc. South Africa, on 17,805 kc. will be on the air during the morning hours, local time.

13 Meters. Increased sunspot numbers will result in more extensive use of this band by foreign broadcasters. Although it will be used primarily by the BBC and the VOA, the Congo has announced transmissions on 21,500 kc. and Ghana will be on 21,545 kc. from 0900 to 1030 EST. Switzer- land has plans to beam transmissions to Southeast Asia from 0330 to 0530 EST.

Broadcast and Long -Wave Bands. Station directories indicate that there are more than 10,000 broadcasting stations operating in the band between 500 and 1600 kc. Of these, approximately 4000 are licensed in the United States. During the daylight hours, reception in this band will not be a problem, since medium -wave transmissions do not propagate to any appreciable distance. At night, however, it will be a serious problem, particularly in suburban areas with congestion and interference from DX stations 500 to 1500 miles distant.

DX'ers should look between the broadcasting channel allocations in North Amer- ica for Europeans, especially Madrid on 584 kc., Lisbon on 755 kc., Rome on 845 kc., Paris on 863 kc., London on 1214 kc., Lille on 1376 kc., Monte Carlo on 1466 kc., and Vienna on 1475 kc. And the VOA maintains a station in Munich on 1196 kc. that can occasionally be heard on the eastern coast of North America.

POPULAR ELECTRONICS

SHORT -WAVE LISTENING

(Continued from page 87

Utility DX'ers Take Note. Jan Tuner, Edi- tor of the Radio Communications DX Club in Sweden, tells us that a new point -to -point guide -a booklet containing 25 pages of addresses, report forms in four languages, frequency lists, advice on reporting, and a list of military stations -is now available. The listed price is $1.20 via surface mail, $1.40

via airmail. For further information, write directly to RCDXC, Kyrkvagen 6A, Kop- parberg, Sweden.

Current Station Reports

The following is a resume of current reports. At

time of compilation all reports are as accurate as possible. but stations may change frequency and/or schedule with little or no advance notice. All times shown are Eastern Standard and the 21 -flour system is used. Reports should he sent to SHORT -WAVE LISTENING, P.O. Box 333, Cherry Hill. N.J., 08034, in time to reach your Short-Wave Editor by the fifth of each month: be sure to include your WPE Monitor Registration and the make and model number of your receiver. We re- gret that we are unable to use all of the reports received each month, due to space limitations, but we are grateful to all contributors.

Afghanistan -R. Kabul, 15.225 kc.. was noted at 1300 -1330 in German with music. This station requires very sharp tuning. Do not confuse it with a nearby propaganda station, or with R. Neder- land which is on 15,220 kc. at a comparable time.

Albania -R. Tirana can be lieu d closing in Span- ish at 1815 on 11,717 kc. but badly squeezed by Moscow and Athens. Major portion of the program is news. This station is also heard in French at 0000 on 9390 kc. and in Eng. to N.A. on 7225 ke. :rt

1900 -1930. Algeria- Algiers, 6049 kc., has an ID in Fremh

at 1604 after a dramatic offering. The station was also noted signing off in Spanish at 1759.

Angola --Local area monitoring of all stations in

Angola has resulted in the following ciuuplet. and up -to -date list (frequencies in parenthesis are offi-

cially listed but not currently in use): Eunissora Oficial de Angola -3375. 4820. 6025. 7235. 9535 ke.

(3955. 4955, 6195. 7265, 9555, 9700, 9760, 17.705 kc.); R. Clube de Angola -4870, 7140. 9630 kc.: R. Ec- rlesis -4985 kc. (11.755 ke.); R. Claim de Cuort_n

Sul -4840, 7285 kc. (6000, 11,970 ke.); R. Clubc rlo

Congo Partugues -6135 ke. (4860 kc. I: R. Cluhe de Mcdanite --4935, 7115 kc.; R. Cluhe du ,M1n.rico -5137 kc.: R. Clube de Cabinda. 5035 ke. (7260 kc.): R. Clube do Lobito -4910, 7175 kc.; R. Damping-

.. 4770, 9615, 11,685 kc. (11,700 kc.); R. Club(' du Huambo -3704. 5065, 7125 ke. (5060, 7160. 9665.

11.925 kc.): R. Clube de Mocannedes- (1740. 5005

5015. 7240. 9515 kc.); R. Cluhe da Hilda-3970. 5025. 9675 kc. (11,940 kc.); R. Clube do Bie -1895. 7390 ke. (7205, 7215 kc.); R. Comereiul de Angola- 3990, 4795. 7155 kc. (3980, 3995. 4775, 4860. 7150 kc.); R. Cluhe de Benguela -5040. 6150 kc. (3395, 3975,

7160. 9505 ke.) Belgium- Eruasels is noted on a new frequency.

9615 kc.. at 1730 -1800 in French and Flemish with pup music.

Brazil- Stations observed recently in the 19- meter band are as follows: R. Jornal do Couuc rcio. Recife. 15,145 kc.: a weak station in Fortaleza- probably R. Clube' do Ceara, 15,165 kc.: R. Mara - juara- Belem. 15.2 -15 kc.: R. Tupi, Rio de Janeiro. 15,370 ke.: R. CLthe Ribeirao Preto (identifying as

November, 1965 125

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PRAT), 15,415 kc.; and R. Nacional, Brasilia, 15,445 kc. In addition, a weak, unidentified station believed to be a Brazilian is on 15,225 kc.

On about 3310 kc., a station announcing as R. Gazetta has been logged from 1911 to 1940 with Brazilian vocal and instrumental music and some announcements and ads in Portuguese, Congo (West)- RadiodifJusion Television Congo - laise was heard on 9718 kc. with African music at 1430 -1530- This Brazzaville outlet is not dual to 9729 kc, Cyprus -A new frequency for the BBC East Medi- terranean Relay. Limassol, is 9580 kc. It was noted with BBC news at 1300 and 1400 and local programming in between. S /off appears to be 1615. Heavy QRM from Yerevan prevents solid copy. Ecuador -Station HOTS, Quito, uses 15,120 kc. at 1430 in Eng., dual to 17,850 kc and 15,105 kc. at 1605 in German. Station HCAH3, R. Trebol (which does not an- nounce as El Trebol), 4915 kc., is noted at 2310- 2345 with typically bouncy Ecuadorian music. An Ill is given every 10 to 15 minutes. The location reportedly is Zaruma but the announcer seems to say "desde Caliban"(?) and mentions Loja often. Ethiopia -Radio Voice of the Gospel, Addis Ababa, has the following current Eng. schedule, Transmitter 1: 0815 -0830 to Ceylon on 15,410 kc.;

1045 -1100 to Ethiopia on 6010 kc.; 1400 -1445 to West Africa on 11,785. Transmitter 2: 0830 -0900 to India on 9730 kc.; 1130 -1145 to Malawi on 9765 kc.; 1300- 1315 to E. Africa on 9565 kc. ; and 1415 -1430 to S. Africa on 9705 kc. There is an Eng. and Zulu xnisn at 1315 -1415 to S. Africa on 9705 kc. on Tues- days. Thursdays, and Saturdays only. Reports also indicate a good signal along the East Coast at 1230 -1300 on 11,845 kc.; this transmission is in Arabic. A late item lists 7268 kc. as now being used at 2245 -2330 daily (except Saturdays) in Sdllali, and from 2330 in Amharic.

Gabon - Radiodiffirsion Television Gabonaise, Libreville, is heard on 4777 kc. with uninterrupted music from 1740 to 1755 /close with announcements in French. Normal closing time is 1800 Sundays, 1630 weekdays.

Germany (East) -R. Berlin International is scheduled to the N.A. East Coast at 2000 and 2130 on 9560 and 11,880 kc., and to the West Coast at 2245 and 2345 on 9770 and 11,920 kc. The 2130 xmsn on 11,880 kc. appears to be the best received. Ghana -Accra has been testing to N.A. in Eng. at 1500 -1600 on 9760 kc. (and on 11,800 kc. in

The listening post of Mike Larcombe, Fol- croft, Pa., contains both a Hallicrafters S -120 receiver and a Heathkit AR -3. Mike, otherwise known as WPE3EAI, has 69 QSL cards; 60 countries logged, 33 verified.

POPULAR ELECTRONICS

SHORT -WAVE MONITOR CERTIFICATE APPLICATION

AALL radio listeners interested in further-

ing the hobby of SWL'ing- regardless of

whether you DX on the BCB, VHF, TV, SW, or FM bands -are eligible to apply for a POPULAR ELECTRONICS "Certificate of Regis- tration." You must have verified (have QSL cards from) a minimum of five radio stations, of which one was outside the borders of the United States. There is no age limit, or special equipment qualification; the only requirement is that the applicant have a sin- cere interest in radio communications.

All certificates are filled in and lettered before mailing; they are mailed flat and un- folded. If you want to register and receive your WPE identification sign, fill in the application blank below. Mail with 50 cents in coin (or stamps) to: MONITOR, P.O. Box 333, Cherry Hill, N.J. 08034. (Per- sonal checks will not be acceptable) .

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127

Arabic), at 2230 -2330 on 6110 kc., at 0100 (possibly from 0030) on 3366, 4825 and 4915 kc., and from 1730 on 4825, 4915, and 4980 kc.

Greece -Forces B/C Station, Athens, was logged on 6045 kc. after VOA s /off at 2345 with music, anmts in Greek and wake -up exercises to 0000. It was also noted at 1603 -1802 with a wide variety of music. This station has been very rarely logged since it was on 7420 kc. about ten years ago.

Italy -Rome broadcasts in Eng. as follows: to N.A. at 2000 -2020 on 11,905 and 9630 kc. ; to Egypt at 0735 -0755 and to Malta during the same time period on 11,905, 9630, and 6010 kc.; to the United Kingdom at 1615 -1635 on 11.905 and 9575 kc. ; to the Near East at 0700 -0730 on 9575 and 6010 kc.; and to Japan at 1705 -1725 on 11.905 and 9710 kc. Ivory Coast -The new International Service from Abidjan on 6015 ke. is heard nicely with arias from Gluck's "Iphegenie en Aulide" at 1650 -1750. The ID is Radiodiffusion Television Ivorienne.

Kuwait -Kuwait is heard daily on 9520 kc. from 1330 to close -down around 1610. Arabic news is given at 1400 and 1600, at times read by a woman. Other programs are varied, consisting of western classical music. Arabic vocal and instrumental tunes, long talks in Arabic. and ID's at 5 -10 minutes before the hour. On the hour, clock bells are rung in seemingly random fashion.

Lebanon --The most current schedule from Beirut reads: to Africa on 11,810 kc. at 1330 -1400 in Eng., at 1400 -1500 in Arabic, and at 1500 -1530 in French; to South America on 11,790 kc. at 1800 -1830 in Por- tuguese, at 1830 -1930 in Arabic, and at 1930 -2000 in Spanish; to U.S., Canada. Mexico, Antilles, and Europe on 9710 kc. at 2030 -2100 in French, at 2100- 2130 in Arabic (to U.S. East Coast), at 2130 -2200 in Eng., at 2200 -2230 in Arabic (to U.S. West Coast), and at 2230 -2300 in Spanish. Omnidirec- tional xmsns are on 5980 kc. at 2330 -0230 and 0915- 1320, and on 9545 kc. at 0430 -0900.

DX States Awards Presented To be eligible for one of the DX States Awards designed for WPE Monitor Certificate holders, you must have verified stations (any frequency or service) in 20, 30, 40, or 50 different states in the U.S. The following DX'ers have qualified for and received awards in the categories indicated.

Fifty States Verified Paul O'Connor (WPE8EUK), Canton, Ohio Clifford Cardwell (WPE5LU), Fort Worth, Texas Marvin E. Robbins (WPEOMW), Broomfield, Colo. Dan Tognetti (WPE6DHV), San Rafael, Calif. Chuck Edwards (WPE4BNK), Fort Lauderdale, Fla. John R. Low (WPE3EWX), Wilmington, Del. Lanny Aldrich (WPE1EL), Burlington, Vt. Edward P. Hensel (WPE3KG), Laurel, Md. Mike Tilbrook (WPE3FTZ), Pittsburgh, Pa.

Forty States Verified Steven M. Stern (WPE2KRM), Highland Park, N. J. Tim Kerfoot (VE3PE1TH), Toronto, Ont., Canada Gregg A. Calkin (VE1PE3L), Saint John, N.B.,

Canada Dick Schier (WPE4HIO), Chattanooga, Tenn. David Smith (WPEIGBC), Everett, Mass. Robert Lauzon (WPE2MWS), Pittsford, N. Y. Dean Christopherson (WPE3GBB), Denten, Md. Michael Moffat (WPE6FAU), Long Beach, Calif. Craig Anderton (WPE2JHM), Ridgewood, N. J. Danny Brodt (WPE3CWJ), Gaithersburg, Md.

Thirty Slates Verified Harrison Vance Mosser (WPE3ESB), Washington,

Pa. Robby Dungan (WPE6FEP), Norwalk, Calif. Joseph E. Marks (WPE9CSA), Chicago, Ill. George E. Molnar, Jr. (WPE2MWB), Buffalo, N. Y. John Vickers (WPE41KQ), Wrightsville, Ga. Bob DuBuiss ,,' (WPE1GGL), Long Meadow, Mass. John H. Long (WPE3DYU), Lebanon, Pa. James A. Sloman (WPE3BZC), Levittown, Pa. J. Paul Ochenkowski (WPE1FYY), Hamden, Conn. Alan Raylesberg (WPE2MKW), Bayside, N. Y. Larry Zigrang (WPE9HLM), South Bend, Ind. Dick Carpenter (WPE2LPX), Newfield, N. Y. Dick Holic (WPE2MGR), Endwell, N. Y. Richard Frcho (WPE8IGR), Cleveland, Ohio Bobby Joe Scott (WPE4HHX), Kingsport, Tenn. Robert J. Wagner (WPE3GIO), Philadelphia, Pa. Stephen Schmidt (WPE2IXG), Webster, N. Y.

Timmy Towery (WPE5DRA), Port Arthur, Texas Bruce Nissen (WPEOEBX), Vinton, Iowa E. Joseph Sabo (WPE7BTZ), Seattle, Wash. John Sowers (WPE2MTE), Hightstown, N. J. Edward J. Salevan (WPE3FRN), Milford, Del. David Smith (WPEIGBC), Everett, Mass. Richard Mauer (WPE2JWI), Orange, N. J. Charles W. Winter (WPE4EQC), Virginia Beach, Va. Charles Hoskins (WPE4GNY), Vinton, Va. John McDonald (WPE9HLW), Chicago, Ill. Tom Weiss (WPE8IGN), Cuyahoga Falls, Ohio Pete Sils (WPEOEAX), Cedar Falls, Iowa Larry Jones (WPE5EFQ), Laurel, Miss. John Stevenson (WPE9GNU), Delaware, Wis. James Drost (WPE2NEH), Hampstead, N. Y. Bob Burckle (WPE4IHZ), Louisville, Ky. Silvio A. Marini, Jr. (WPE4IIO), East Point, Ga. Larry Hoffman (WPEOEGK), University City, Mo.

Twenty States lc rifted Bobby Conder (WPE4HQT), Winston -Salem, N. C. Kenneth A. Fraga (WPE2NPH), New York, N. Y. Douglas McKirahan (WPE9HSZ), Oak Park, Ill. Gary R. Cumiskey (WPE9HMT), Elkhart, Ind. Jim Archibald (WPE9HNR), Belleville, Ill. Ronald Kumor (WPE8HXN), Detroit, Mich. Donald Hughes (WPE6GBB), Big Bend, Calif. Jim Keller (WPEOEID), Grandview, Mo. Noel Vander (WPE1GHU), Bedford, Mass. Thomas Berlinger (WPE2NIR), Bronx, N. Y. Lawrence J. Pearce, Sr. (WPE6GAW), Barstow,

Calif. John Januszewski (WPE2JGX), Sayreville, N. J. Gregory K. Gebele (WPE2NAK), Lakewood, N. J. Chester W. Wood, Jr. (WPEOELH), St. Paul, Minn. Ross Lambert (WPE2MFS), Riverdale, N. Y. John and Richard Hanelko (WPE3GKC), Pitts-

burgh, Pa. Les Scofield (WPE8IIU), Kalamazoo, Mich. Bruce Collier (WPEOELA), Council Bluffs, Iowa Wayne L. Elsmore (WPE7CCK), Klamath Falls,

O reg. John A. Brebner (VE3PE2EL), Kingston, Ont.,

Canada


SHORT-WAVE

annri -Announcement BBC -Brit i-h Broadcasting

C'urpora t h m lirnmlc;t-ting

Eng. I:n¢Ii.h If) Identifecation kc.--Kili cycles

ABBREVIATIONS

N.A. North America Q R M-St at ion interference R. Radio doff- Sign -off I O.1- Voice of America xnun -Transmission xmtr- -Transmitter

Maldive Islands -After long test xntsne. Mali Sink() Radio is now conducting regular broadcasts at 0200 on 9650 lie. in Hindi, Singhalese, Tamil. and Japanese. Hus anyone logged this station as yet:' We'd appreciate receiving the complete schedule as well as the address and technical information.

Mexico -Station XEMP. Mexico City. 11,740 kc.. is now using the ID La Clrarrita del Cuadrante. It is being heard from 1815 to 2015 in Spanish.

New Guinea -R. W'ettnk. VL9CD. Papua. has been noted weakly on 3335 kc. with a world nerf- bulletin in Eng. at 0300 followed by a varied music program.

Pakistan -Karachi uses 9614 kc. in parallel with 11.672 lue. for the Turkish xmsn at 1345 -1430. The 9740 -kc. frequency listed by some sources is not being used.

Peru -The mysterious R. Union, 6115 kc., is heard at 0100 -0200 with dance music: the only ID's noted to date consist uF con una pttu!jrcttna especial de bailable.s -a Call -sign is never given. nor a location. Some sources list R. Ltt,7., Lima, as being un

6115 kc.; however, it is actually on 3355 kc. and fair from 2200 tu 2330/s /off with classical music. anntts, and commercials in Spanish.

Poland- W:0'mi v s latest schedule reads: tu South America in Polish at 1800 -18:30, 1830 -1900.

1930 -2000. and 2000 -2(130 and in Spanish at 1900-

1930 and 2030 -2055 on 9675, 11.840, and 15,120 kc.; to Australia and New Zealand in Eng. rat 0230 -0300

and 0330 -0400 and in Polish at 0200 -0230 and 0300-

0330 on 9675. 11.840, and 15,120 kc.: to Africa in Eng. at 0700 -0730 and 0800 -083(1 and in French at 0730 -0800 and 0830 -0900 on 7125, 11.840, and 15.12(1

kc., in Eng. at 1400 -1430 and in French at 1330-

1400 on 7285 and 9675 kc., in Eng. at 1700 -1730 and in French at 1730 -1800 on 7125. 7145, 7285. 9675. and 11,840 kc.

Portugal -Lisbon is operating at tinges on 7225 kc.

at 173(1-1830 with pop music and Portuguese language in a beam tu Sao Tome, Angola. and Mo- zambique; from 1830 to Brazil. The La Vrac del Oceitlente service was heard at 2120 -2145 but not dual to 6025 or 6185 kc.

Samoa (Western) -A short -wave xmtr is reported to be in operation at Apia on 6040 or 6140 kc.

Schedule and the correct frequency are requested. Somali Republic -R. Mogadiscio, 4968 kc.. has

been noted opening in Arabic at 2200 with wrll news: an ID at 2212, then Eng. news; from 2.22(

with native- language news, probably Somali. This is in dual to 7160 ke.

South Africa -The South African BIC Corp. will spend $5.6 million to build the most powerful radio xmtr in Africa, according to one news source. It will be used to send a true image of the republic and its people to the outside world, the article said. Broadcasts will he made in nine languages. However, there was no mention of frequencies to he used nor a target date fur the opening of the station.

Spanish Guinea- Euti.ROra de Radiadijttsion San ta Isabel, Fernando Po, 6250 kc., is excellent at times with uninterrupted Chopin etudes from 1658 to 1735: then light pup music to 1752 /close. S /off anntts were in Spanish and a brief march preceded the actual close.

Tahiti -Both outlets of R. Tahiti are giving excellent results on the West Coast, but the 6140 -kc. outlet is now better than the 11,825 -kc. outlet. The former is best around 0000 -01041 in French. the

November, 1965 129

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POPULAR ELECTRONICS

November 1965 ADVERTISERS INDEX

READER SERVICE NO. ADVERTISER PAGE NO.

I Allied Radio 138, 139, 140. THIRD COVER American Basic Science Club, Inc. 21 American Institute of Engineering

& Technology 114 2 Amperex Electronic Corporation ..FOURTH COVER 4 Amphenol Distributor Division.

Amphenol -Borg Electronics 12 5 Antenna Specialists Co., The 97

51 P s K Manufacturing Co. 109 7 Blonder Tongue 9

50 British Industries -Garrard 6 8 Browning Laboratories, Inc. III 9 Burstein -Applebee Co. III

Capitol Radio Engineering Institute, The 16, 17. 18, 19

Cleveland Institute of Electronics 102, 103, 104. 105 10 Cleveland Institute of Electronics 129 II Conar Y0

Consolidated Auto Wholesalers 133 Coyne Electronics Institute 114

12 Datak Corporation 125 DeVry Technical Institute 3 Edmund Scientific Co. 126

3 Electro Products Laboratories, Inc. 118 4 Empire Scientific Corp. 100 5 Fanon Electronic Industries, Inc. 5 6 Finney Company 31 7 Fisher Radio Corporation 23

Grantham School of Electronics 119 8 Hallicrafters 125 9 Heath Company 98, 99

Hitchings 126 20 Hy -gain Electronics Corp. 101 54 Intercontinental Electronics School 100 21 International Crystal Mfg. Co., Inc. 39 22 International Rectifier Corp. 7 53 JFD Electronics Corporation 13 23 Johnson Company. E.F 33 24 Kuhn Electronics Inc. 126 25 Lafayette Radio Electronics 121, 122

Mackenzie 124 6 Mark Products 4

26 Mercury Electronics Corp. 127 36 Mctrotek Electronics. Inc. 107 27 Micro Electron Tube Co. 135 28 Miller Company. J.W. 106 29 Milwaukee School of Engineering 8 30 Multi -Elmac Company 10

Multicore 124 31 Nation -Wide Tube Co. 137

National Radio Institute ..SECOND COVER, I, 38 National Technical Schools 68, 69, 70, 71

32 Olson Electronics Incorporated 129 33 Progressive "Edu- Kits" Inc. 112 34 RCA Electronic Components and Devices 11 35 RCA Electronic Components and Devices 40

RCA Institutes, Inc. 34, 35, 36, 37 RTS Training Center 114

52 Ray -Tel 30 37 Sams & Co.. Inc., Howard W. 115 38 Schober Organ Corporation, The 108 39 Scott, Inc., H.H. 29 49 Semitronics Corp. 32 40 Shure Brothers, Inc. 14 41 Sonar Radio Corp. 113 42 Topaz Incarpo.a:td 116 43 Turner Microphone Company, The 25 44 U. S. Army 26, 27 45 University Sound 117 48 University Sound 117

Valparaiso Technical Institute 124 46 Vero Electronics, Inc. 116 47 Weller Electric Corp. 28

CLASSIFIED ADVERTISING 131, 132, 133, 134, 135, 136, 137

SHORT -WAVE CONTRIBUTORS Henry unman, Jr. (IVPEI(:( l',. Worcester. Mass. Roger Catlike (Il PEIGEK). Manchester, N. H. Perry Brainin (fiPE2KVK /, Bronx, N. V. Alai; Raylesberg (WPE2MK11.), Baysidc. N. W. Doug Lamerson (It'PE211N.V), Richmond Hill. N. W. Al Sauerhier (l1 PE2.A'D.4), Washington, N. J. Ira Schultz ( II /'E2.WGG), White Plains, N. W. Jay Hans (11 /'F. J.VGJ ). White Plains, N. Y. Paul Mayo (11'PF2.A'J(:), Brooklyn, N. Y. Ronnie Tamagni (ll PE2N('K), Vineland, N. J. Grady Ferguson (1'PE-1B('), Charlotte, N. C. Jack Keene (IVPE5BMP), Houston, Texas James Helmke (IVPESDCV), San Antonio, 'Texas Gary Kieffer (WPE5DZD), Tecumseh, Okla. Jack Stephenson (Il'PE5 A A), Oklahoma City. Okla. Shaler Hanisch (IVPE6BP.V), Pasadena, Calii. Trey Clegg (R'PE6F.4F), Fresno, Calif. Stan Slonkosky (WPE7CEJ), Globe, Ariz. Melvin Hickman (11'PE7CF. \" 1. Walla Walla. Wash. Dan Schonberg (1VPERF117I). 'baker Heights. Ohio William Carlile (l1'PERIISO i. (olumbo Ohio R. D. Palmer (WPE9AST). Decatur, Ill, Gerry Dexter (WPE9BDB), West Bend, Wis. A. R. Niblack (11'PEOK.11). A incenses, rnu. John Beaver, Sr. (ll'PEP.IE), Pueblo, Colo. Jack Perolo (PV2PEIC), Sao Paulo, Brazil Bert l'estor (VE3PE9L), Sudbury, Ont., Canada Charles Bailey, Athens. Ga. Jerry Batman, Greenville, S.C. George Bennett. Anderson, Ind. Robert Harris, Syosset, N. V. Bob Hill, Boston. Mass. Gus Hindenlang, East Moriches, N. V. Paul Judkins, Herndon, Va. Joe Piechuta, l'lantsville, Conn. Bert Pryor, Athens, Ga. Christopher Schwink, Williamsville. N. Y. Radio Voire of the Gospel, Addis Ababa. Ethiopia Sweden Calling DX'ers Bulletin, Stockho,m, Sweden

latter around 2200 with Tahitian -language programming.

Thailand -R, Thailand, HSK9, Bangkok, operates to N.A. at 2315 -0015 with news in Eng. at 2325, and in their General Overseas Service at 0525 -0657 with news in Eng. at 0530, on 11,910, 7185, and 6160 kc. for the Thai Forces in Korea, Republic of Vietnam and Cambodia at 0430 -0520 and in a Home Service relay at 0800 -0900, on 11,910 kc. There is no Eng. listed for the two latter xmsns. Reception reports are requested and will be verified by card and acknowledged by letter. Return postage is not required.

Tunisia -Tunis I, 6195 kc., in the Arabic Network. overrides the BBC with chanting at 2345, an anmt in Arabic at 2348. then wake -up exercises. It is QRM'cd after 0000 by the BBC and another signal, probably that of R. Burundi.

Windward Islands -St. Georges has moved up from 5010 kc. to 5020 kc. where it is heard at 1730- 2115. The 19 -rooter outlet has also moved, this time to 15.130 kc.: try for it around 1530. East Coast listeners and those in the southern states might also try for one of the medium -wave network stations: Castries on 1565 kc. (down from 1580 kc.); St. Georges on 540 kc.; Roseau on 695 kc.: and Kingston on 705 kc. All of the latter stations broadcast with 500 watts except the 250 -watt Castries outlet.

Medium Waves Your Short -Wave Editor frequently monitors 800

kc. evenings to check on the signal of PJB, Trans World Radio, Bonaire. It generally runs fair to good despite the presence of two 50,000 -watt Canadian stations, CKLW in Windsor, and CJAD in Montreal, as well as the 150,000 -watt voice from XELO in Ciudad Juarez, Mexico. But we were surprised recently to receive the following report from a listener just thirty miles from CKLW: "PJB cones in here fair to good at 2100 with religious talks." This is the first time anyone living within 200 -300 miles of either CKLW or CJAD has reported the 800 -kc. outlet. -3( -


ELECTRONICS MARKET PLACE COMMERCIAL RATE: For firms or individuals offering commercial products or services. 90¢ per word (including name and address). Minimum order $9.00. Payment must accompany copy except when ads are placed by accredited advertising agencies. Frequency discount: 5% for 6 months; 10% for 12 months paid in advance. READER RATE: For individuals with a personal item to buy or sell. 554 per word (including name and address). No Minimum! Payment must accompany copy.

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FOR SALE

FREE! Giant bargain catalog on transistors, diodes, rectifiers, SCR's, zeners, parts. Poly Paks, P.O. Box 942. Lynnfield, Mass. MESHNA'S TRANSISTORIZED CONVERTER KIT $4.50. Two models converts car radio to receive 30 -50 me or 100 -200 me (one me tuning). Meshna, Lynn, Mass. 01901. ELECTRONIC Ignition Kits, Components. Free Diagrams. Anderson Engineering, Epsom, New Hampshire 03239. GOVERNMENT Surplus Receivers, Transmitters, Snooper - scopes, Radios, Parts, Picture Catalog 20¢. Meshna, Nahant, Mass. DIAGRAMS for repairing Radios $1.00. Television $2.50. Give make model. Diagram Service, Box 1151 PE, Man- chester, Connecticut 06042. CB WPE QSL Cards. Samples Free. Radio Press, Box 24, Pittstown, New Jersey. ROCKETS: Ideal for miniature transmitter tests. New illustrated catalog, 250. Single and multistage kits, cones, engines, launchers, trackers, technical information, etc. Fast service. Estes Industries, Penrose 18, Colorado. "SPECIAL! WPE- SWL -CB -QSL cards, 3 colors, $2.50 per 100 -Free Samples, Garth, Jutland, New Jersey." CANADIANS -GIANT Surplus Bargain Packed Catalogs. Electronics, Hi -Fi, Shortwave, Amateur, Citizens Radio. Rush $1.00 (Refunded). ETCO, Dept Z., Box 741, Mont- real, CANADA. TV CAMERAS, transmitters, converters, etc. Lowest factory prices. Catalog 104. Vanguard, 190 -48 99th Ave., Hollis, N.Y. 11423, WEBBER Labs. Transistorized converter kit $5.00. Two models using car radio 30 -50 Mc or 100 -200 Mc, one Mc spread. Easily constructed. Webber, 40 Morris, Lynn, Mass. JAPAN & Hong Kong Electronics Directory. Products. components, supplies. 50 firms -just $1.00. Ippano Kaisha Ltd., Box 6266, Spokane, Washington 99207. CANADIANS, TRANSISTORS AND PARTS. Free catalogue contains reference data on 300 transistors. J. & J. Elec- tronics, Dept. PE, Box 1437, Winnipeg, Manitoba. TRANSISTORIZED CONVERTER 26-200 MC. Receive signal from 26 to 200 MC (1 MC spread), on broadcast band using car radio, crystal control or tuneable (1 MC spread). Kit $11.00 pp. Wired $20.00 pp. Webber Labs, 40 E Morris St., Lynn, Mass. COMPONENTS? Kits? Hardware? For catalogue write Trans -Vu -Pats, Box 267, Chelsea, Mass. 02150. QSL's BROWNIE W3CJI 3111A Lehigh, Allentown, Pa. 18103. Samples 104 with catalogue 254.

TRANSISTORS -Miniature Electronic Parts. Send for free Catalog. Electronic Control Design Company, P. O. Box 1432K, Plainfield, N.J.

CITIZEN BANDERS! Get base station Performance with your mobile units. No modifications or soldering necessary- Proven performance. Send for free details or send ($15.00) to: T. Francis, 15 Park Row, N.Y. 38, N.Y.

November, 1965

DETECTIVES! Free brochures! Electronic intelligence devices for your needs and budget. SILMAR ELECTRONICS, 3476 N.W. 7th Street, Miami, Fla. 33125. INVESTIGATORS, FREE BROCHURE, LATEST SUBMINIA. TURE ELECTRONIC SURVEILLANCE EQUIPMENT, ACE ELECTRONICS, 11500 -L NW 7TH AVE., MIAMI 50, FLA.

CONVERT any television to sensitive, big -screen oscilloscope. Only minor changes required. No electronic experience necessary. Illustrated plans, $2.00. Relco In- dustries, Box 10563, Houston 18, Texas. BUY Appliances, Cameras, Watches, etc. at factory prices plus 10%! Free Details! Cam Company, 436 -11 Bloomfield Ave., Verona, N.J. 07044. NEW Supersensitive transistor locators detect buried gold, silver, coins. Kits, assembled models. $19.95 up. Free catalog. Relco -A33, Box 10563, Houston 18, Texas.

AMAZING NEW electronic miracle transforms your TV room into a Stereophonic Theatre! Free details and Free Gift! Consolidated Acoustics, 1302C Washington, Hobo- ken, N.J. 110VAC 60cy from car generator. Powers lights, refrig- erator, transmitter, receiver, etc. Simple, easy to convert. Plans $2.00. Tedco, P.O. Box 12098, Houston, Texas 77017. ACHTUNG! Das machine is nicht fur Gerfingerpoken und mittengraben. Is easy schnappen der Springenwerk, blowenfusen und poppencorken mit spitzensparken. 1st nicht fur gerwerken by das Dummkopfen. Das rubber - necken sightseeren keepen hands in das pockets. Relaxen und watch das Blinkenlights. This attractive, brass metal plaque only $2.00 each, ppd. Southwest Agents, Dept. P, 8331 Hwy. 80 West, Fort Worth, Texas 76116. WALKIE- TALKIE. Construct 2 "xl "x1/2 " transistorized, long range, 100 milliwatt marvel for $10. Plans, FREE GIFT, $2.00. Baker Electronics, R.R. 3, Greencastle, Ind. TELEPHONE VOICE SWITCH: (LS -500). ACTUATES AUTO- MATICALLY AND UNATTENDED ANY TAPE OR WIRE RE- CORDER. PICTORIAL INSTALLATION INSTRUCTIONS INCLUDED. $23.75. POST PAID USA, WJS ELECTRONICS. 737 NORTH SEAWARD, HOLLYWOOD, CALIF. 90038. INVESTIGATORS: KEEP IN STEP WITH ADVANCEMENTS IN THE ART OF ELECTRONICS FOR THE PROFESSIONAL. SEND $1.00 FOR EQUIPMENT BROCHURE. WJS ELEC- TRONICS, 737 NORTH SEWARD, HOLLYWOOD, CALIF. 90038. BUG DETECTOR: WILL DETECT AND LOCATE SURREPTI- TIOUS TRANSMITTING DEVICES IN CONFERENCE ROOMS, HOME AND OFFICES, ETC. WRITE FOR DETAILS. WJS ELECTRONICS, 737 NORTH SEWARD, HOLLY- WOOD, CALIF. 90038. DIAGRAMS --SENT AIRMAIL -- TELEVISION $3.00. RA- DIO 1919.1965 $2.00. GIVE MODEL. DIAGRAMS, BOX 55, WILLIAMSPORT, PA. 17704. SAFEGUARD PRIVACY! New instrument detects electronic 'bugs,' wire -tapping and snooping devices. Freb information. Dee Equipment, Box 7263 -E7, Houston 8, Texas. CB- WPE -QSL CARDS. Same High Quality, Beautiful, Glossy multi -color cards. New LOW PRICES. 26 SAM- PLES, 254. Dick, W8VXK, 19QA0625, Gladwin, Mich. 48624.

131

NEW Mfrs. Surplus Record Changers B.S.R. stereo cartridge & 45 adapter $15 each. Changers, Inc., Box 144, Jerome Ave. Sta., Bx., N.Y. 10468.

LASER: Hobbyists, experimenters, amateur scientists. Build your own coherent -light optical laser. Complete instructions, drawings. schematic diagrams and parts list. $6.00. Same as above, diode laser, $3.00. Technical Writers Group, Box 5501, State College Station, Raleigh, N.C. 27607. REVERBERATOR (ECHO) UNIT: Build your own. Complete plans, drawings, schematic and parts list. $3.00. Use with automobile radio, home radio or record player. Technical Writers Group, Box 5501, State College Station, Raleigh, N.C. 27607.

RADAR: Build your own ultrasonic doppler radar. Detect motion of people, automobiles, even falling rain drops. Transistorized, uses standard small 9 -volt battery. Com- plete plans, drawings, schematic diagrams and parts list. $4.00. Technical Writers Group, Box 5501, State College Station, Raleigh, N.C. 27607. TV CAMERA: Build your own. The real thing -no rotating disc. Uses 5 tubes plus videcon tube. Output: 72 ohms .

and also any channel 2 to 6. Receive on any TV set without modification. Excellent circuit -good picture. Complete plans, drawings, schematic and parts list. $6.00. Technical Writers Group, Box 5501, State Col- lege Station, Raleigh, N.C. 27607. STROBOSCOPE: Build your own. Observe wheels, fan blades, gears, etc. while rotating. Uses 2 tubes and neon bulb. Complete plans, drawings, schematic and parts list. $3.00. Technical Writers Group, Box 5501, State College Station, Raleigh, N.C. 27607.

CIRCUIT Boards, Parts for "Poptronics" projects. Free catalog. DEMCO, Box 16297, San Antonio, Texas 78216.

TRANSISTOR ignition systems. Famous "Operation Pick- up" kit finest components only $13.95 Postpaid. Also other systems and components available. Free catalogue. ELECTROMART, Box 2680, Milwaukee, Wisconsin 53214.

"GREAT BUYS" Catalog 10¢. Multimeter Special $9.95, VHF Transmitter, Stepping Switch, Torroid Assemblies, UHF Grounded Grid, VHF Transistorized Amplifiers, Vari- acs 5a -10a, Mercury Relays. Fertik's, Ninth Tioga, Phila., Pa. 19140.

INVESTIGATORS- DETECTIVES -INDUSTRIAL SECURITY OFFICERS: New 1966 line of Electronic Surveillance De- vices. Incorporating most advanced subminiature design. Greater range; lower battery drain; unique sophisticated circuitry; extremely durable. HIGH QUALITY PROFES- SIONAL EQUIPMENT AT ROCK BOTTOM PRICES. Fool- proof wireless units are extremely SIMPLE TO USE! You DO NOT have to be an engineer to get PROFESSIONAL results with THIS equipment. TROL 1966 models ready NOW! Take advantage of Special Introductory Offer. Don't delay! For FREE details write TROL ELECTRONICS - PE, 342 Madison Avenue, New York, N.Y. 10017.

SURVEILLANCE equipment- Hottest on Market today. Complete Kits, Free Brochure. Tri -Tron, Inc., 7800 Phoenix NE, Albuquerque, New Mexico 87110.

LOWEST Prices Electronic Parts. Confidential Catalog Free. KNAPP, 3174 8th Ave. S.W., Largo, Fla.

TRANSISTORIZED REGULATED POWER SUPPLY. 7 -25V DC, 225MA, ±.35 % regulation. Complete kit -$13.95 pp. Plans- $2.00. Viking, 706 Prentice, Albert Lea, Minnesota 56007.

DETECTIVES: ELECTRONIC SURVEILLANCE DEVICES. LOW COST. SIMPLE OPERATION. FREE BROCHURE. DE- TECTION SYSTEMS -PE, BOX 455 GRAND CENTRAL, NEW YORK CITY 10017.

ELECTRONIC "Crackajacks," transistors- photocells -relays. Guaranteed prize box $1.00 plus 15¢ pp. DART ELECTRONICS, Box 214, Jericho, N.Y.

PLANS ONE TUBE DX Shortwave kit (12,000 record) 24 pages -50¢. Experimenter's catalog 250 exclusive items -250, refundable. Laboratories, 993 -L, Redwood City, Calif. QSL CARDS -Best quality, price. Write Jac -Mar, Box 522, Dos Palos, Calif. for price list.

LOOKING FOR TREASURE? Complete Detailed Circuit Information to Build Low -Cost Transistor Metal Locator and Small Detector Two Circuits $2.00. Treasure Hunter, Box 1796, Costa Mesa, Calif.

FREE ELECTRONICS (new and surplus) parts catalog. Bigelow Electronics, Bluffton, Ohio 45817.

CLASSIFIED ADVERTISING ORDER FORM Please refer to heading on first page of this section for complete data concerning terms, frequency discounts, closing dates, etc.

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BUILD A "LIVE" TV CAMERA CHEAPER THAN EVER! Simplest 5 tube circuit to date. EXCELLENT PERFOR- MANCE acclaimed by hundreds of constructors all over the country. Circuit specifically designed to use maximum number of standard, readily available parts -most can be obtained from "junkbox" or discarded TV sets. We furnish only the hard -to -find components and EASY -TO- FOLLOW PLANS. Choose from 6 different kits (including printed circuit models). Prices start as low as $16.95! Plans included FREE with each kit or available separately for $3.- refundable with later order of any kit. PERFECT FOR HAMS, EXPERIMENTERS, SCIENCE FAIR STUDENTS. Check our unbelievable prices. RUSH 10¢ FOR INFORMATION PACKED CATALOG. Box 396P, ATV RESEARCH, South Sioux City, Nebr. 68776.

ANEMOMETER (electric wind speed indicating system) complete with meter, cable, transmitter and walnut desk stand, plus FREE rain gauge -$19.95 -Send money order and save shipping charges. Pioneer Sales Co., Box 7151, Dallas, Texas.

FREE ELECTRONICS (new and surplus) parts catalog. Bigelow Electronics, Bluffton, Ohio 45817.

TV CAMERAS. Model 400 complete with good vidicon and lens. Used as demonstrators. Only $200 F.O.B. Vanguard, 190 -48 99th Ave., Hollis, N.Y. 11423.

FM STEREO Tuner, alignment generator. Kit $79.50, Wired $99.50. AmerLabs, 471 Clifton Avenue, Newark 4, N.J.

TV CAMERA UNDER $40.00 -completely transistorized space age Flying Spot Scanner- Schematics, Photo- graphs. Plans- $3.00. Beck, 2950 Sarah Court, Newbury Park, Calif. 91320.

CB CRYSTALS -SUBMINIATURE Types Only $1.50 each. Postpaid. List of Channels Available. Quaker Electron- ics, Hunlock Creek, Pa.

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1965 SEDANS...only $995 FULLY GUARANTEED! :

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120 E. 56 St., New York, N.Y. 10022 PHONE: 12121: 421 -2223

WE SELL CONSTRUCTION PLANS. Telephone Equip- ment: $40 Answering Machine, $15 Bell System Type Speaker Phone, Phonevision $10 Legal Telephone Con- nector, Telephone Extension in your cars, $25 Automatic Dialer, Central Dial System. Television Equipment: $50 Camera, $30 3DTV Converter, $35 All Electronic Color Converter, Video Recorder. Hobbyist: $50 Ultrasonic Dishwasher, Transistorized Teletype, $75 Electron Mi- croscope, Electronic Tranquilizer, Private Eye Tail Trans- mitter, Police Radar Detector plus Legal Jammer, ALL ELECTRONIC TYPEWRITER. Plans $4.95 each. Air Mail Service 504 each. SUPER HOBBY CATALOG 104. Don Britton Enterprises, 7906 Santa Monica Blvd., Holly- wood, Calif. 90046.

QSL- CB -SWL (letters) Cards. Samples 104. MARTIN, 828F SCHUYLKILL AVENUE, READING, PENNA. REVERBERATOR: Build your own echo box for car radio, stereo, guitar. Complete instructions, Schematics and parts list $3.00. Technical Publications, University Sta- tion, Box 14084, Gainesville, Fla.

SPECIAL PL -259 Connectors 294 (10 lot) 404 Single. Postage Paid. Reduced Prices on all Radio Parts, Tubes, Equipment. Midwest Radio Company, 110 East Kansas, Smith Center, Kansas.

35 INVISIBLE inks! Formulas $1. Kirk, 8831 Sagebrush, San Antonio, Texas 78217.

ROBOTS -Build your own. List of Unique Schematics - 254. P.O. Box 12303, Fort Worth, Texas.

ELECTRONIC LIGHTER. No Flint, Wick, Battery or Mov- ing Parts. Wagner, 6200 -A Whitewood, Library, Pa. 15129.

VIDEO TAPE RECORDER: VKR -500 factory wired $295.00. Box 27881, Los Angeles, Calif. 90027.

MOTOROLA, new miniature seven tube, 455 KC IF amplifier discriminator with circuit diagram. Complete at $2.50 each plus postage. R & R Electronics, 1953 S. Yellowsprings, Springfield, Ohio.

COLOR -BAR Generator, Sencore CG -126, Unused, Only $102; Jeff Fiala, 2523 S. Homan, Chicago 60623.

50 EASY -To -Build transistor projects. Handbook, $1.95. HiFi Kits, Transistors, Modules. Brandwein Co., 306 W. 100 St., N.Y.C., N.Y. 10025.

HAM EQUIPMENT

CBER'S, HAMS, SWL'S! 3 -30 MC Preselector kit, $18.98. Clipper -filter kit, $10.99; wired $14.99. GW -10, GW -11, GW -12 Preselector kits, $8.99, wired $11.99. Free catalog. HOLSTROM ASSOCIATES, P. O. Box 8640 -E, Sacramento, Calif. 95822.

November, 1965 133

WANTED

CASH Paid! Unused tubes, electronic equipment. Barry, 512 Broadway, N.Y.C. 12.

QUICKSILVER, Platinum, Silver, Gold. Ores Analyzed. Free Circular. Mercury Terminal, Norwood, Mass.

URGENTLY NEED MILITARY SURPLUS: ARC -27, ARC -34, ARC -38, ARC -44, ARC -52, ARC -55, ARC -73, ARC -84, ARN -14, ARN -18, ARN -21, ARN -59, 51X- 2/17L -7, RT- 66 /GRC THRU 70, RT -77 /GRC -9, GRC -19, Test Sets with ARM, UPM, URM, USM, SG Prefixes. Top Dollar Paid. Slep Electronics Company, Drawer 178ZD -PE, Ellenton, Fla. 33532. Phone (813) 722.1843.

SHORTWAVE LISTENING

SWL GUIDE, English programs listed by the hour. DOUBLE LISTENING PLEASURE. $2.00. SWL Guide, 218 Gifford, Syracuse 2, N.Y.

LP RECORD -- Shortwave station announcements, inter- val signals, anthems, Pakistan, Jerusalem, Sudan, many more. Broadcast quality. $3.95 postpaid. SWL RECORDS, P. 0. Box 150, Culver, Calif. 90231.

HIGH FIDELITY

"LOW, Low quotes: all components and recorders. HiFi, Roslyn 9, Penna." HI -FI Components, Tape Recorders, at guaranteed "We Will Not Be Undersold" prices. 15 -day money -back guarantee. Two -year warranty. No Catalog. Quotations Free. Hi- Fidelity Center, 1797 (P) 1st Avenue, New York, N. Y. 10028.

FREE! Send for money saving stereo catalog #P11E and lowest quotations on your individual component, tape recorder, or system requirements. Electronic Values, Inc., 200 W. 20th St., New York, N.Y. 10011.

TUBES

BEFORE You Buy Receiving Tubes, Transistors, Diodes, Electronic Components and Accessories . send for Giant Free Zalytron Current Catalog, featuring Standard Brand Tubes: RCA, GE, etc. -all Brand new Premium Quality Individually Boxed, One Year Guarantee -all at Biggest Discounts in America! We serve professional servicemen, hobbyists, experimenters, engineers, technicians. Why Pay More? Zalytron Tube Corp., 469 -E Jericho Turnpike, Mineola, N. Y. 11502.

TUBE Headquarters of the World! Free Catalog (tubes, electronic equipment) write! Barry, 512 Broadway, N.Y.C. 12.

RADIO & T.V. Tubes -330 each. Send for free list. Cornell, 4213 University, San Diego, California 92105.

TUBES "Oldies ", latest. Lists free. Steinmetz, 7519 Maplewood, Hammond, Indiana 46324.

STEREO TAPES. Save up to 60% (no membership fees, postpaid anywhere U.S.A.). Free 60 page catalog. We discount batteries, recorders, tape accessories. Beware of slogans "not undersold," as the discount information you supply our competitor is usually reported to the factory. SAXITONE, 1776 Columbia Road, Washington, D.C.

RENT 4 -TRACK STEREO TAPES -Narrow it down, it has to be TRIMOR- Goodbye to partial satisfaction -Service and Dependability our keynote -ALL LABELS and TITLES BROCHURE and TAPE CATALOG. TRIMOR Company P. 0. Box 748, Flushing, N.Y. 11352. TAPE -MATES makes available to you -ALL 4 track stereo tapes -ALL labels- TREMENDOUS SAVINGS - POSTAGE FREE to your door -for FREE BROCHURE write TAPE -MATES, 5280 -PE W. Pico Blvd., Los Angeles, Calif. 90019. TAPE RECORDER SALE. Brand new, latest models, $10.00 above cost. Arkay Sales, 1028 -C Commonwealth Ave., Boston, Mass. 02215. TAPES: Recorders: Accessories: Finest Quality, lowest prices. Send for free list and premium offers. Tape Mart, Dept. B, 39 -17 47th Avenue, Long Island City, N.Y. 11104. TAPE -MATES offers the world's first 3 HOUR -Long play stereo library- CLASSICAL- POP -JAZZ -DANCE and VA- RIETY -top recording artists -ONLY $9.95 -FREE TAPE - MATES membership with initial order -for FREE BRO- CHURE write TAPE -MATES, 5280 -PE W. Pico Blvd., Los Angeles, Calif. 90019. TAPE transport. NAB recording studio quality. Build yourself for amazingly low cost. Detailed plans $5.00. Free particulars. Pepke Laboratories, 309 -B West 19 Street, New York, N.Y. 10011. CONCORD Model 330 automatic telephone connection Surveillance Accessories. Free Details. Electronics, Box 301, N.Y. 10028.

TAPE -MATES now offers the first completely PORTABLE CAR -STEREO PLAYER- nothing to install -can be used in CAR -HOME -OFFICE -BOAT, etc. Also complete CAR - STEREO MUSIC LIBRARY available -for FREE BRO- CHURE write TAPE- MATES, 5280 -PE W. Pico Blvd., Los Angeles, Calif. 90019.

PLANS AND KITS

SENSATIONAL LISTENING: SENSITIVE POCKET VHF POLICE RECEIVER. Easily assembled. Plans $2.00. Otta- wa Sales, Box 627, Holland, Mich. 49424.

TRANSISTORIZED FM TRANSMITTER kit $7.50 (less mike). FM radio kit $8.50, Plans $1.50 each. Radcon, 1736 Minnesota, Fairfield, Calif. 94533. KITS, Solar Powered Radio $3.95, Wireless Transmitter $4.95. ELECTRONIX, Box 42 -A, Madison Heights, Mich. 48071. TACHOMETER! Fully Transistorized for All make cars. 0- 10,000 RPM. Build for under $7.00. Send $2.00 for details. Group Laboratory, Box 87, Prospect Hts., Ill. 60070.

FREE Catalog. Electronic parts, tubes. Wholesale. REPAIRS AND SERVICES Thousands of items. Unbeatable prices. Arcturus Elec- REPAIRS AND SERVICES tronics ZD, 502 -22 St., Union City, N.J. 07087.

TAPE AND RECORDERS

TAPE Recorders, Hi -Fi, components, Sleep Learning Equipment, tapes. Unusual Values Free Catalog. Dress - ner, 1523PE, Jericho Turnpike, New Hyde Park 11, N. Y.

BEFORE Renting Stereo Tapes try us. Postpaid both ways -no deposit- immediate delivery. Quality -Dependability -Service- Satisfaction -prevail here. If you've been dis- satisfied in the past, your initial order will prove this is no idle boast. Free Catalog, Gold Coast Tape Library, Box 2262, Palm Village Station, Hialeah, Fla. 33012.

RENT Stereo Tapes -over 2,500 different -all major labels -free brochure. Stereo -Parti, 1616 -PE Terrace Way, Santa Rosa, California.

134

TV Tuners rebuilt and aligned per manufacturers speci- fication. Only $9.50. Any make UHF or VHF. We ship COD. Ninety day written guarantee. Ship complete with tubes or write for free mailing kit and dealer brochure. JW Electronics, Box 51C, Bloomington, Indiana.

CLEAN Equipment Works Better, Sells for More. Vacuum Cleaner Nozzle, Stem 8"x3/8" $1.50. Spitz, Box 4095, Arlington, Virginia 22204.

EQUIPMENT

McGEE Radio Company. Big 1966 Catalog Sent Free. America's Best Values. HiFi- Amplifiers- Speakers -Elec- tronic Parts. Send name, address and zip code number to McGee Radio Company, 1901 McGee Street, Dept. EG, Kansas City, Mo. 64108.

POPULAR ELECTRONICS

MAGNETS

ALNICO -CERAMIC- FLEXIBLE -ASSEMBLIES. What you need, we have. Maryland Magnet, 5412H Gist, Baltimore, Md. 21215.

ROOKS

FREE Book. Prophet Elijah Coming Before Christ. Wonder- ful Bible Evidence. PE Megiddo Mission, Rochester, New York 14619.

FREE Catalog 48 page Electronic -Aerospace Books, Aero Publishers, Inc. 329 Aviation Rd. (PE), Fal!brook, Calif.

PATENTS

INVENTIONS; Ideas developed for Cash /Royalty sales. Raymond Lee, 130 "G" W. 42nd, New York 10036.

INSTRUCTION

LEARN While Asleep, hypnotize with your recorder, phonograph. Astonishing details, sensational catalog free! Sleep- Learning Association, Box 24 -ZD, Olympia, Wash.

FCC License in 6 weeks. First Class Radio telephone. Re- sults Guaranteed. Elkins Radio School, 2603B Inwood, Dallas, Texas.

HIGHLY- effective home study review for FCC commercial phone exams. Free literature! Cook's School of Electronics, Craigmont, Idaho 83523.

REI First Class Radio Telephone License in (5) weeks Guaranteed. Tuition $295.00. Job placement free. Radio Engineering Institute, 1336 Main Street, Sarasota, Fla.

ELECTRONICS -F.C.C. License Training- Correspon- dence, or resident classes. Free details. Write: Dept. 3, Grantham Schools, 1505 N. Western, Hollywood, Calif. 90027.

LEARN ELECTRONIC ORGAN SERVICING at home all makes including transistors. Experimental kit-troubleshooting. Accredited NHSC, Free Booklet. NILES BRYANT SCHOOL, 3631 Stockton, Dept. A, Sacramento 20, Calif.

PICTORIAL Study In Amateur Radio. Free Details. Dwight Cross, 1212 Lynch, St. Louis, Mo. 63118.

FCC LICENSE TRAINING THROUGH TAPE RECORDED INSTRUCTION. Bob Johnson Audio -Visual License Train- ing, 221 S. Sepulveda, Manhattan Beach, Calif.

MOVIE FILMS

THIS Christmas, Give or Get INDY "500" 8mm Color Movie Library by "pro" cameramen. Three most thrilling Indianapolis "500" Races -1963 is $10.95 ppd. -1964 is $11.95 ppd. -1965 is $12.95 ppd. Outstanding $35.85 Value! Buy All 3 Together ONLY $31.95 ppd., SAVE $3.90. Send Check or money order to: SPORTLITE "500" FILMS, Dept. CPE, 20 N. Wacker Drive, Chicago, III. 60606.

MAGAZINES

VARIOUS backdate electronic magazines. ... List 10¢. Landa, 30525.

HELP WANTED

EARN extra money selling advertising book matches. Sample kit furnished. Matchcorp, Dept. MO -115, Chicago, Ill. 60632.

373.

024 A7GT B3GT H4G H5GT L4 L6 N5GT Q5GT

2A3 2A F4 3BC5 3BH6 3BZ6 3C B6 3C F6 3CS6 3LF4 3Q4 4BZ7 5AS8 5AT8 5AV8 5AW4

513 /(7 516 578 5U4G 5U8 6A7 6A8 GA B4 6AC7 6A F4 6B8 6BA6 6BC5 68C8 6606 6C4 6C5 6C6 riCB6 6C D6G 7A4/XXL 7A5

MICR O ELECTRON

Co. Potersorl55'

Park Station 3, New Jersey

P. O. 0

LARGE, SELECT

END FOR COMPL

SERVICE DE.

E TUBE LIS. IST 7A6 7A7 25AV5

25B46 35Y4 250916 35Z5GT 25L6GT 37

39/44 42 43 45

80

58A5

84/6Z4 11723

7A8 7B4 7B5 766 7B7 7B8 7C4 2A8 2AQ5 2AT6 2AT7 2A U6 2A U7 2AV6 2AV7 2AX4GT 2A X7 9BG6G

978 24A

25W4G 2525 25Z6 26 35A5 3585 35C5 35L6GT 35W4

25 -Watt Ì9t e Send

Power a. for Transistors 3 for 5200 u..t Transistor

S21.S5Ia. On.oa vol. control button, plastic oar Nue. tauon

replaceable hat erics fine).

All tubes lab -tested for mutual conductance. life test. Guar. FREE 1 yr. replacement y tub, falling under all operating condo Adv. robes not n sadly n may be elec. pert. fact seconds or lned- clearly marked.

POSTAGE PAID. Send 35c handlg. for orders under $5, 25% dep. ('.O.n.'s. Send approx. Post. on Can. R foreign orders.


INVENTIONS WANTED INVENTIONS wanted. Patented; unpatented. Global Mar- keting Service, 2420 -P 77th, Oakland 5, Calif. INVENTORS. We will develop, help sell your idea or invention, patented or unpatented. Our national manufacturer clients are urgently seeking new items for outright cash sale or royalties. Financial assistance available. 10 years proven performance. For free information, write Dept. 41, Wall Street Invention Brokerage, 79 Wall Street, New York 5, N.Y.

INVENTORS! Sell your invention for cash or royalties! Our client manufacturers eagerly seek new items. Patented. Unpatented. Financial assistance if needed. 25 years proven performance. For free information, write Dept. 20, Gilbert Adams, Invention Broker, 80 Wall St., New York 5, N.Y. INVENTORS! Outright cash sale or royalties for your inventions. Patented. Unpatented. Active demand from our client manufacturers. Financial assistance available. Write Dept. 35, United States Invention Brokerage, 78 Wall Street, New York 5, N.Y. INVENTORS! Don't sell your invention, patented or unpatented, until you receive our offer. Eagle Development Company, Dept. P, 79 Wall Street, N.Y. 5, N.Y. PATENT Searches including Maximum speed, full airmail report and closest patent copies, $6.00. Quality searches expertly administered. Complete secrecy guaranteed. Free Invention Protection forms and "Patent Informa- tion." Write Dept. 9, Washington Patent Office Search Bureau, 1426 G Street, N.W., Washington 4, D.C. INVENTORS Needing Help with any problem, financial, development, securing manufacturer, obtaining patent. Write the organization that delivers action and results - not promises. Pioneer Invention Service, Dept. 79, 150 Broadway, New York 38, N.Y.

November, 1965 135

AUTHORS' SERVICES

AUTHORS! Learn how to have your book published, pro- moted, distributed. FREE booklet "ZD," Vantage, 120 West 31 St.. New York 1.

WANTED WRITERS! Short stories, articles, books, plays, poetry. Will help place. sell your work. Write today, free particulars! Literary Agent Mead, Dept. 37A, 915 Broad- way. New York 10, N.Y.

RECORDS

DISCOUNT Records. All Labels -Free List. Write Cliff House, Box 42 -P, Utica, N.Y.

PROTECT YOUR RECORDS! Two Cleaning Cloths $1.00. Towers, Lafayette Hill, Pa. 19444.

GOVERNMENT SURPLUS "GOVERNMENT SELLS ". -Surplus Electronics; Oscillo- scopes; Transceivers; Test Equipment; Radar; Walkie- Talkies; Boats; Jeeps; Aircraft; Misc. -Send For -"U.S. Depot Directory- Procedure " -$1.00- Service, Box 425 (ZE), Nanuet, N.Y.

GOVERNMENT Surplus. Complete Sales Directory $1.00. Surplus Publications, Box 45781E, Los Angeles 45, Calif. JEEPS from $53.90 ... Trucks from $78.40- Boats, Type- writers. Airplanes, Electronic Equipment, 100,000 Bar- gains "as is" Direct From Government in Your Area. Complete Sales Directory and Surplus Catalog $1.00 (De- ductible First $10.00 Order). Surplus Service, Box 820 -J, Holland, Michigan. JEEPS - WALKIE- TALKIES - Receivers - Oscilloscopes - Transmitters-Voltmeters. Uncle Sam's Bargain Prices. Write For Latest Exciting Details. Enterprises, Box 402 -B2, Jamaica, N.Y. 11430.

HYPNOTISM FREE Hypnotism, Self- Hypnosis. Sleep Learning Cata- log! Drawer H400, Ruidoso, New Mexico 88345. HYPNOTIZE UNNOTICED! PATENTED new hand device makes you a Hypnotist first day or refund! Hypnotist's Handbook included! $2.00 Hypnosis Foundation. Box 487, La Mesa 9, California.

PHOTOGRAPHY -FILM, EQUIPMENT, SERVICES

MEDICAL Film -Adults Only- "Childbirth " -1 reel 8mm $7.50 -16mm $14.95. International -E, Greenvale, L.I., New York. SCIENCE Bargains- Request Free Giant Catalog "CJ" -148 pages -Astronomical Telescopes, Microscopes, Lenses, Binoculars, Kits, Parts. War surplus bargains. Edmund Scientific Co., Barrington, New Jersey.

EDUCATIONAL OPPORTUNITIES

LEARN While Asleep. Remarkable, Scientific, 92% Effec- tive. Details Free. ASR Foundation, Box 7021, Dept. e.g., Lexington, Kentucky. B.Sc. DEGREE (Engineering) or College Entrance by home study. Send $1 for 1966 Prospectus. CIST, Suite 692, 263 Adelaide St. W., Toronto, Canada.

DO -IT- YOURSELF

TRANSISTORIZED Two Band Kit, Tunes Aircraft, Foreign, Police and Broadcast. $5. Headset $2. Ekeradio, Box 131, Temple City, Calif.

FREE "How To Buy Government Surplus Information" With 20 pounds of New Surplus Electronic Equipment. Tubes, Transistors, Relays and countless other valuable components for $4.95. Send $1.00 deposit, shipped via parcel post. Evergreen Electronics, Box 2233, Everett, Washington 98202.

MUSIC

SUB carrier detector adds programs of continuous, commercial -free music thru any FM tuner when plugged into multiplex output of tuner. Hear the hidden background music programs now on FM. Kit, no alignment necessary, $49.50. Wired unit $75.00. Music Associated, 65 Glen- wood Road, Upper Montclair, New Jersey, Tel. 201 -744- 3387. POEMS wanted for songs and records. Send poems. Crown Music, 49 -DT West 32, New York 1.

MUSICAL INSTRUMENTS ACCORDIONS, GUITARS, BAND INSTRUMENTS! Save to 50%. Terms. Trades. Free trial. Free catalog. Mention instrument. MUSIC MART, 5535 -PE Belmont, Chicago 60641.

REAL ESTATE

FLORIDA WATER WONDERLAND -Home. cottage Mobil - sites. Established area. $590 full price, $9.00 a month. Swimming, fishing, boating. Write: Lake Weir, Box KG38, Silver Springs, Fla. AD 6 -1070 (F -1)

FREE!- FALL -WINTER CATALOG Big, 180 Pages! Selected Best thruout the U.S. Thousands of properties described, pictured -Land, farms, homes, businesses -Recreation, Retirement. 490 offices, 35 states coast to coast. World's Largest. Mailed FREE! STROUT REALTY, 50 -ZD E. 42nd St., N.Y., N.Y. 10017.

FREE! 152 -page FALL -WINTER catalog! Over 1700 PIC- TURES! Farms, Ranches, Homes, Businesses, Vacation and Retirement Properties in 28 states coast to coast! UNITED FARM AGENCY, 612 -EP West 47th St., Kansas City, Mo. 64112.

136

PERSONALS

INVESTIGATORS, FREE BROCHURE, LATEST SUBMINIA- TURE ELECTRONIC SURVEILLANCE EQUIPMENT. ACE ELECTRONICS, 11500 -K NW 7TH AVE., MIAMI 50, FLA.

"HYPNOTIZE .. One word .. One fingersnap," on stage. Satisfaction -or refund. $2.00. Hypnomaster, Box 9309 -

E8, Chicago 90.

PHOTOGRAPHS

PHOTOGRAPHS and transparencies wanted, to $500.00 each. Valuable information free -Write Intraphoto -PE, Box 74067, Hollywood 90004.

DETECTIVES

DETECTIVE Opportunities. Experience unnecessary. Write, Wazgner, 125 West 86th, New York 10024.

STAMPS

TURKEY 50 different 5¢ approvals. Hijop, Box 505, Nor- ristown, Pa. 19404. SPECIAL TRIPLE OFFER -111 All Different Stamps -25 All Different Topicals -Full Year's Membership in Las Vegas Stamp Society -All for $1.00. Our system puts your duplicate stamps to work for you, and gives you full catalog value for same. KINNEAR, 558AG Oakey Blvd., Las Vegas, Nevada 89105.

500 FINE MIXED U.S. 150. Wright, Box 753 -X, Hagers- town, Md. 21740.

EMPLOYMENT INFORMATION

FOREIGN Employment. Construction, other work projects. Good paying overseas jobs with extras, travel expenses. Write only: Foreign Service Bureau, Dept. D, Bradenton Beach, Florida.

POPULAR ELECTRONICS

COINS

FIFTY Indian Pennies $14.00. BROOKLINE COIN, Box G, Auburn, Mass. NOW! Get 3 Real Old Lincoln Cents! Send 100 and receive 1919, 1920 and 1925. (Only one set to a customer.) Other offers on approval. Littleton Coin Co., Littleton T12, N.H.

BUSINESS OPPORTUNITIES

INVESTIGATE Accidents -Earn $750 to $1,400 monthly. Men urgently needed. Car furnished. Business expenses paid. No selling. No college education necessary. Pick own job location. Investigate full time. Or earn $6.44 hour spare time. Write for Free literature. No obligation. Universal, CZ -11, 6801 Hillcrest, Dallas 5, Texas. VENDING Machines -No Selling. Operate a route of coin machines and earn amazing profits. 32 -page catalog free. Parkway Machine Corporation, 715PE Ensor Street, Baltimore 2, Md. ELECTROPLATING Equipment and supplies. All types for home workshops and industrial. Send $1.00 (refundable) for equipment guide formulas, operating data, catalog. HBS Equipment Division 90, 3543 East 16th, Los An- geles, California. 90023. I MADE $40,000.00 Year by Mailorder! Helped others make money! Start with $10.00 -Free Proof. Torrey, Box 3566 -N, Oklahoma City, Oklahoma 73106. PIANO Tuning learned quickly at home. Tremendous field! Musical knowledge unnecessary. Information free. Empire School of Piano Tuning. Dept. PE, Box 327, Shen- andoah Station, Miami, Florida 33145. (Founded 1935.) FREE Book "990 Successful, little -known Businesses." Work home! Plymouth -845K, Brooklyn, N.Y. 11218.

SELL CB EQUIPMENT -Dealerships available to ag- gressive people who can sell Citizens Band Radio full or part time. Knox Electronic, Dept 194, Galesburg, III. 61401. GET INTO CUSTOM UPHOLSTERY. Turn Old Furniture into big $$$ spare time. Reupholster chairs, divans like new. Make custom slip covers, drapes. No experience required. We supply everything. Write for Big FREE illustrated Book on Easy Home Instruction and how we start you in big $$$ home business. Modern Up- holstery Institute, Box 899 -OJ, Orange, Calif. RAISE RABBITS for us on $500 month plan. Free details. White's Rabbitry, Mt. Vernon 28, Ohio.

NEW PUBLICATION. "Green Dollar Gold Mines." Pro- fessional business secrets for success and profits in radio and TV repairing. $5.95. United Products Co., 922 W. Grove St., Bloomington, III. 61701.

OBTAIN abundant capital for your business. Details free. McReynolds, 406 West D Street. Elizabethton, Tenn. 37643. WHY RENT ? ? -$3,800.00 Builds $8,000.00 Home. Instruc- tions- $1.98. Homecraftsman, 552 Front, Scranton, Pa. 18505. EARN MORE MONEY as a Microwave Systems Engineer. Illustrated handbook gives complete fundamentals of microwave propagation, limitations. Valuable aid to planning, evaluating microwave systems. Send $1.00 to Box 1882, Indianapolis, Ind. 46206.

MISCELLANEOUS

HYPNOTIZE secretly, cleverly, one glance ... or money back. $2. Eltons, Box 18223 -PE2, Indianapolis, Indi- ana, 46218. BEERS, PEACH BRANDY, WINES- Strongest Formulas, $2.00. (Complete brew supplies- hydrometers catalog 10¢)- Research Enterprises, 29 -D Samoset Rd., Woburn, Mass. WORLDWIDE Export and Buyers Guide $1.50. Burke Asso- ciates, Manchester, Mass.

November, 1965

NATIoNS WIDE TUBE C0:

or a type

TUBES ANY TYPE NOT

LISTED MAY ALSO

BE ORDERED AT

354 each. óo)

($33 per

024 IA7 163 1H5 11(3 1 L6 1w5 IRS 155 1U4 1X2 2CW4 2054 2DV4 3626 3076 3V4

5ÁT8 5J6 5U4 513 647 6464 6ÁC7 64F4 64G5 64H4 6415 6AM8

64N8 6405 6AU4 6AU6 6A V5 6AV6 6AW8 64X4 6BA6 6BC5 68E6 68H6 661(7 6BL7 6BN6 6605 6806 6607 6C4 6CB6 6C06 6CG7 6CM7 6CY5 60A4 60E6 601(6 61306 6054

60V4 6J5 6.16 61(6 6S47 6507 6SF7 6507 65117 65.17

6X4 7AS 747 7B6 768 7C5 7E6 iái 7Y4

Every order of 999 ore you get

free u self -ocre. ice Console Tube Checke . Het. Val. SI!9. Rnught alone $39.96. 651(7 6517 6SN7 65127 6U5 6U8 6V6 6W4 6W6

$33 Per

WHORED

SAWS 8CG7 9AU7 100E7 11CY7 12A06 12AF6 12AT7 12AV6

12AX4 124U7 124X7 12646 126E6 12BH7 12817 12C5 12CA5 1216 1265 12547 12567 1251(7 12507 12W6 18FY6 18FX6 220E4 2516 25Z6 32L7 5045 SOCS 50L6 11717 117Z3

It Annual Sale Buy any of the tuber listed here at the regular price of 35G and receive a second tube for only 1e. Buy 100 tubes for 033.00 and receive the second 100 tubes for just $1.00. Types may be mixed. Offer expires Dee. 31, 1965. 6AC7 6A116 6CG7 6AG5 69N7 6AX4 6DE4 SOCS

TERMS: FREE POSTAGE in USA on prepaid orders Add 504 for handling on orders under $5. Send 25%

deposit on COD orders. Send Approx. postage on Canadian & Foreign orders.

Money refunded in 5 dava if not comp let ey satisfied.

Tubers a 'd or seconds are

Sends for complete tube list! Thin is current price list and eon previous price Itaini

NATION WIDE TUBE CO. 406 HARRISON AVENUE, HARRISON, NEW JERSEY HU 4 -9848


RADIO ANNOUNCING. Learn Home! Books, magazines: Disk Jockey, Box 11 -PE, Aberdeen, South Dakota 57401.

"GIANT ARMS" Dr. Young's D.C. Revolutionary discovery. $2 00. Satisfaction or refund. Gaucho, Box 9309 -S8, Chicago 90, III.

STAMMER -Stutter -No More. (Dr. Young). Write: Gau- cho, Box 9309 -E8, Chicago 90.

"MUSCLE BUILDING SHORTCUT." $2. Uses self -hypnosis. Results or refund. Elton's, Box 18223 -PE27, Indianapolis, Ind. 46218.

100 Wine, Cider and Beer Recipes. All State and Federal Laws. 10 Day Guarantee. $2.50. Country Winemaker, Box 243EG, Lexington, Mass. 02173.

WINEMAKERS: Free illustrated catalog of yeasts, equipment. Semplex, Box 7208, Minneapolis, Minn. 55412.

POEMS Wanted For New Songs. Tin Pan Alley, Inc., 1650 Broadway, New York, N.Y. 10019.

ENVELOPES. Paper. Ribbons. Stencils. Carbons. Ink. Catalog: Tower, Lafayette Hill, Pa. 19444.

NOW IS THE TIME ... FOR ALL CLASSIFIED ADVER- TISERS to place their ads in the 3 outstanding Ziff - Davis Electronics Handbooks. Your low cost classified ad in the 1966 COMMUNICATIONS and ELECTRONIC EXPERIMENTER'S HANDBOOKS will be read and responded to for an entire year: 1966 COMMUNICATIONS HANDBOOK, $0.75 Word; Spring 1966 ELECTRONIC EXPERIMENTER'S HANDBOOK, $0.75 Word; Fall 1966 ELECTRONIC EXPERIMENTER'S HANDBOOK, $0.75 Word. Special Combination Rate for all 3 Handbooks - $1.55 Word. Combination Rate for COMMUNICATIONS and SPRING ELECTRONIC EXPERIMENTER'S HAND- BOOKS only -$1.10 Word. CLOSING DATE FOR COMBI- NATION RATES: October 25, 1965. Send order and remittance today to: Hal Cymes, Classified Ad Manager, ELECTRONICS HANDBOOKS, One Park Avenue, New York, New York 10016.

137

411/Ea ELECTRONICS FOR EVERYONE 1966

OUR 450, YEAR CATALOG 260

ea

COMPLETE knight-kit- CAI Alqt.'

ALLIED RADIO MN WESTERN AVE CHICAGO. ILE. 606110 NA 1.01001Mu Cod. 3121

SrE 4acrùa Guaia..: rtivNf or YOU,. Ma.MV Back

508 VALUE-PACKED PAGES including exclusive products and special values available only

from /iL UED

send today for your

Allí/Ea 1966 CATALOG

world's largest selection

SAVE MOST ON:

Stereo Hi -Fi Tape Recording

CB 2 -Way Radio

FM AM & AM Radios

Short Wave Radios

Portable TV Phonographs

Amateur Gear

Intercoms & P, A.

Automotive Electronics

Test Instruments TV Tubes & Antennas

Power Tools, Hardware

Parts, Tubes, Transistors

MORE OF THE BEST IN ELECTRONICS FOR EVERYONE

EASY TERMS Use the convenient Allied Credit Fund Plan -over 24 months to pay

138

i ALLIED RADIO

The World's Largest Electronic Supply House Printed in U.S.A.

i

satisfaction guaranteed or your money back

POPULAR ELECTRONICS

* S S

sPeciaLin your FREE 1966 ALLIED CATALOG

see what's new in the wonderful world of knight -kits®

KG -895 Superba Series 120 -Watt Solid -State Stereo Amplifier Kit. $149.95

- 999 9,9

KG -635 5 -Inch DC to 5.2 Mc Wide -

band Oscilloscope Kit. $99.95

KG -371 Solid -State Auto DC Power Timing Light Kit. $19.95

C -540 Low -Cost 5 -Watt Citizens Band Transceiver Kit. $49.95

------- ;. I I

..p MU IIA a

KG -964 Superba Series 64 -Watt Solid -

State FM -AM Stereo Receiver Kit.

$189.95

KG -375 Solid -State U n ive rsalAu to Ana- lyzer Kit. $49.95

maid KG -221 FM Moni- tor Receiver Kit (police, fire, marine, weather bands, etc.) $39.95

KG -201 Solid -State Motor -Speed /Light Control Kit. $9.95

Safari -I Deluxe 23- Channel Citizens

Band Transceiver Kit. $129.95

KG -415 Superba Series Professional Solid -State Stereo Tape Deck Kit. $249.95

Knight -Kit GUARANTEE: Buy any Knight -Kit.

Build it. Operate it. You must be satisfied or we

refund your money.

THERE IS A knight -kit FOR EVERY NEED!

easiest to build -enjoy big savings Stereo Hi -Fi CB 2 -Way Radio Short -Wave Hobby Kits Test Equipment Automotive Intercom Amateur Gear

FREE Send today for your 508 -page Allied 1966 value -packed catalog

send for your 508 -page 1966 Allied Catalog

ALLIED RADIO, Dept. 3-L 100 N. Western Ave., Chicago, III. 60680

Send FREE 1966 Allied Catalog

Name

Foe!

PLEASE PRINT

Address

City State Zip

ALLIED RADIO L. CIRCLE NO. 1 ON READER SERVICE PAGE

PICK ANY NUMBER FROM 1G3GT TO 19ÁU4

AND YOU'RE A WINNER!

1030111E1301

1X28

3876

3186

31K5

3915

48L6

4EH7

4E37

4065

4H95

5H08

508

6AL5

6AU4GTn

6AU6A

6Á06

69X4GT0

6896

6BL8

6826

6C8611

6CG7

6DT6

6E87

66J7

6665

6GJT

60 K5

6066

60W8

6H05

6H08

6S4A

6SN7GTB

6Ú8A

6119

6X9

6Y9

8805

8CW5

918

10CW5

12A17

12Á07A

121104018

12Á679

15CW5

1618

19A04


..AND ON AND ON. FOR THE COMPLETE LIST, WRITE:

AMPEREX ELECTRONIC OORYORAT ION, HICKSVILLE, L. I., NEW YORK 11802.

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