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la the "budget" price range, there is no finer speaker system on the market. In fact, careful comparison proves that Jensen's beautifully balanced TF -3 is unquestionably the finest ... not only the "best buy" ... but point for point, the best system -and you pay much less. Compare ... components: The TF -3 uses a 10' FLEXAIR" woofer, effective from 25 cycles, two special midrange units, and the new Jensen Sono- Dome`Ultra Tweeter. .. so brilliant a speaker, it does not even begin to operate until 10,000 cycles! power ratings: The TF -3 drives to full room volume with a good quality 10 watt . It does not require a 20 watt amplifier for clean performance. enclosures: In the Jensen TF -3 you get top quality construction 1/4" gum hardwood, rigidly built. It stains beautifully -or paint or build -in as you choose. Dimensions: 131/2"H.,H., 232/3 "W., 113/8 "D. Compare , .. price: There is no real comparison. $79.50 You are invited to make these comparisons -and any others you wish- between the Jensen TF -3 and any other "rated" speaker system on the market regardless of price. Comparison with the thrilling sound of the

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www.americanradiohistory.com NOVEMBER, 1960 Radio -Electronics Formerly RADIO -CRAFT - Incorporating SHORT WAVE CRAFT - TELEVISION NEWS - RADIO & TELEVISION* OVER FIFTY YEARS OF ELECTRONIC PUBLISHING

Hugo Gernsback editorial Editor and Publisher 33 Future Space Traffic -Hugo Gernsback M. Harvey Gernsback Editorial Director Fred Shunaman radio Managing Editor 38 FM Finally Makes It-David Lachenbruch Robert F. Scott W2PWG, Technical Editor 43 How to Fix Radios Faster (and Make More Money)-Jack Darr Larry Steckler 56 Convert to Economical Hi -way FM -John J. Borzner Associate Editor 80 Simple FM Converter for TV Uses Minimum Parts I. Queen Editorial Associate - Jonathan Vanderwall Elizabeth Stalcup Production Manager electronics Fernando Martinez Art Director 34 Electromyography -Dr. Bernard S. Post Wm. Lyon McLaughlin 46 Build the Rally -Pal Computer (Cover Feature) -Jack Allison Tech. Illustration Director 55 New for Radar Fred Neinast Art Associate 62 Lee Robinson 98 6E5 for Circuits-Rufus P. Turner Director, Advertising Sales John J. Lamson Eastern Sales Manager what's new G. Aliquo 63 Pictorial Reports of New Developments Circulation Manager Adam J. Smith Director, Newsstand Sales audio -high fidelity Robert Fallath Promotion Manager 40 6DZ7 Amplifier Is Neat Job to Make -Robert M. Voss 52 New Stereo Pickups, Part III -Julian D. Hirsch 71 Improving PA Systems -Leo G. Sands Average Paid Circulation Over 163,000 industrial electronics II 0;11 FIDEI.ITI 49 Subcarrier Techniques for Telemetry -Ed Bukstein 79 The Transient , What's It For ?- De /lroye D. Darling ON THE COVER test instruments (Story on page 46) 42 Construct a Tunnel - Noise Generator -I. Queen Behind the wheel and 58 Simple -to -Build Sweep Generator Uses Varicap- Morris Barron ready to begin a sports car 91 PNP -NPN Transistor Oscillator Easily Built T. Merkler rally, the driver sets up his -F. home -made electronic com- puter. The device will help television h:m to be in the right place at the right time -vital if 60 Servicing TV Distribution Systems, Part I -Jack Beever he is to be a winner. 64 TV Service Clinic -Conducted by Jock Darr Color original by Jack Allison. 84 Legal Pitfalls -Leo T. Parker 90 Sawtooth Sticklers- Robert P. Balin the departments Circuits 121 Business and People 99 New Patents 119 Noteworthy News 118 Corrections 102 New Products 112 Technicians' 26 Correspondence 115 New Tubes and 110 Technotes 130 New Books Semiconductors 124 Try This One 127 New Literature 6 News Briefs 120 50 Years Ago

Gernsback Publications. Inc, Executive. Editorial and Advertising Offices, 154 West Radio -Electronics November, 1960, Vol. XXXI, No. 11. Published monthly at. Mt. Hugo Gernsback, Chairman at Mt. Morris. 14th SI.. New York I1. N.S. Telephone Algonquin 5- 7755. Morris, III., by Gerttsback Publications, Inc. Second -class postage paid G. Aliquo, Secretary. Inc. All rights reserved under Universal, of the hoard: M. Harvey Gernsback, President; III. Copyright 1960 by Gernsback Publications. 400 South International and Pan -American Copyright Conventions. Advertising Representatives: Los Angeles: Harker-Gusted-Coughlin, Sr. Tel. DUnkirk 7- 2:128. San Francisco: Harker -Gusted-Coughlin, 444 $5.00 for one $9.011 for Alvarado Subscription Rates: U.S., L?.S. possessions and Canada, year' 1 -0151. Chicago: 8631 East Prairie Road, Skokie, Ill. Tel. one $11.00 for Market St.. Tel. GArfield two years; $12.00 for tivee years. Pan -American countries $6.00 for year: 5- :;740. a year; $12.00 for two Oltchard Iwo years; $15.00 for three years. All other countries $6.50 Publishing and Distributing Co., Ltd., 18 Nears; $16.50 for three years. Foreign Agents: Great Britain: Atlas ];rì ale Lan ,-. London E.C. 4. Subscriptions: Address correspondence to Radio -Electronics. Subscription Dept.. 154 to: RADIO -ELECTRONICS. 154 West requesting a change of address, please fur- Postmaster: If undeliverable, send Form 3579 West 14th St., New York 11, N.Y. When York 11. N.Y. *Trademark registered 13. 8. Pat. Office. nish an address label from recent issue. Allow one month for change of address. 14th St_, New RADIO -ELECTRONICS 4

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www.americanradiohistory.com n riefs Hoover, Jr., Power Converter on Market cussed in more than 50 papers to be K6USA by Herbert presented at the 13th Annual Con- W6ZH, son of the former President Thermionic power converters, pro- ference on Electrical Techniques in who, as Secretary of Commerce, con- ducing electricity direct from heat, Medicine and Biology. The confer- tributed greatly toward the recog- are now being turned out commer- ence is being held in Washington, nition of the American amateur com- cially by General Electric at the D. C., on Oct. 31, Nov. 1 and 2. radioist and to his present status. pany's power -tube plant at Schenec- Authorities from both the medical tady. The devices, somewhat similar and electronic fields, including the Voice of Africa? in action to a two- element vacuum US Department of Agriculture, the The Voice of America has con- National Institutes of Health and a tracted for construction of a power- large number of American univer- ful station to be built near Monrovia, sities and medical, scientific and elec- Liberia. It will consist of six 250 -kw tronic concerns, will take part in the and two 50 -kw transmitters. It will eight sessions of the conference. give the Voice of America coverage Main subjects are grouped under of Africa, parts of central Europe analytical methods and instrumenta- and the middle East. tion, electroanalytical methods, in- The Voice will operate under inter- struments, digital computers, tele- national rules and will not interfere metry of physiological data, ana- with other African broadcasts. Com- logues and system analysis and gen- pletion is expected in 1962. The eral discussion. engineering design of the new sta- tion is being handled by Page Com- California Amateur Honored munications. Contracts for the actual Raymond E. Meyers, W6MLZ, of construction of the transmitters has tube producing "contact- potential" San Gabriel, Calif., was awarded the not been let at the time of writing. current, are about the size of a silver Edison Radio Amateur Award for dollar. They will produce at least 1 1960. The plaque is given each year Jap Radios Self- Limited? watt apiece, according to K. E. Wil- by General Electric to an outstand- In an attempt to maintain the son, who is in charge of marketing ing amateur. prestige of Japanese transistor ra- the new converters. They operate at Meyers' award was given, in the dios, the Ministry of International a temperature of 1100 °C. words of the citation: "For promot- Trade and Industry has been clamp- Efficiency is 2.5%. Since electricity ing on restrictions and obtaining in- is required to heat the cathode, the formation looking toward an export chief applications of the new con- quota. First step of the MITI was to verters will be for special and experi- ban export of all radios containing mental uses. less than three transistors. This was softened slightly to permit export of Short -wavers Cooperate such radios only if plainly labeled as Plans to reduce interference in toys. The ministry explained that the short -wave broadcast bands have the little radios have been hurting been put into effect by the Inter- the market for six -transistor or big- national Frequency Registration ger sets. Board (IFRB) pursuant to decisions American manufacturers pointed made at the Geneva Conference last out that the move would have little year. Administrations concerned effect on Japanese competition, as with short -wave broadcasting are to no American manufacturers make submit their schedules to the IFRB two -transistor radios. four times a year. The IFRB com- pares schedules and, where stations Humans Telemetered would interfere, proposes improve- W6MLZ, Raymond E. Meyers (left), re- A new manned vehicle monitor ments to the parties concerned. At ceives Edison Award from B. S. Angwin that can tell at a glance the imme- the end of each period, the IFRB of G -E. diate condition of a pilot and the will publish a "High Frequency ing international good will through craft he is flying has been designed Broadcasting Schedule" which in- his skillful planning, organizing, es- for the Air Force Flight Test Cen- cludes the schedules of the various tablishing and operation of extensive ter, International Telephone & Tel- broadcasters, to which the notified world -wide radio communications egraph Laboratories announced. changes have been applied, and indi- during the Ninth Plenary Assembly The new device, to be manned by cates those changes that the admin- of the Consultative Committee on ground personnel, will give for the istrations did not consider satisfac- International Radio (CCIR) held in first time direct readout or "real - tory. It is hoped that this system Los Angeles in April, 1959. The spe- time" safety reports on the physio- will substantially reduce short -wave cial radio station, K6USA, handled logical and environmental conditions interference. more than ten thousand important of the pilot, in addition to teleme- communications during the confer.- tered "how goes it" information on Electronic Medicine Meet ence." the vehicle itself. Electric and electronic techniques W6MLZ was assisted in setting up According to Paul Sehnert, proj- in biology and medicine will be dis- the radio service extended by (Continued on page 10) -ELECTRONICS 6 RADIO

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8 RADIO -ELECTRONICS

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YOUR FCC LICENSE FREE OR YOUR MONEY BACK find out how .. . Completion of the Master Course (both Sections) will prepare you for a First Class Commerical Radio Telephone License with a Radar Endorse- You ment. Should you fail to pass the FCC examina- can handle the new electronic tion for this license after successfully completing devices. the Master Course, you will receive a full refund of all tuition payments. This guarantee is valid for the entire period of your enrollment agree- ment. 2. You can solve the problems that stump your fellow technicians. 3 . Training is Job Insurance when em- ployment is tough to find ... and Successful more money for you when times Electronics are good.

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www.americanradiohistory.com (Continued from page 6) ect initiator of Edwards Air Force Base, and Carlos Miller, executive A perfect fit every time engineer of ITTL, the "real- time" console will keep abreast of man's conditions within fractions of a sec- ond and can indicate immediately when he is undergoing or entering an unsafe condition. No computation of data, graph or gauge analysis is necessary.

,w.,.,. -VEHICLE Cn,m..r+2,n

The information displayed on the vehicular panel includes various sta- bility and aerodynamic parameters, structural strains, flutter, power - plant behavior, and other data such as skin temperature, fuel, fire warn- ing and electrical equipment. The information shown on the physiological panel includes the man's heart rate, blood pressure, temperature, breathing rate and vol- ume, the parameters concerning his environment, oxygen supply, acceler- ation, radiation count, etc. The cathode -ray displays will pre- ist -Tab Controls sent a green color indication of the OK condition. It changes to a harsh orange when either the actual value or the rate- of- chc.nge becomes un- safe. For the plot displays of inter- related parameters, the green spots These CENTRALAB tab -mounted Radiohm® Controls of light are located inside "safety - are sure to suit you -because they're tailored to the envelope" areas which have been minimum shaft length needed for TV set hidden previously determined for the 'par- controls. When you need a longer shaft, you simply ticular parameters for both the man use the 2" polyethylene extension packed with each and the vehicle. The spots of light change their color to orange when unit. Nothing to saw -a snip of the scissors gives you the parameters move outside these an insulated shaft of the length you need, and the areas. adjustment slot is still there, and still easy to get at. Bell Begins Paging System CENTRALAB Twist -Tabs are available in 25 values from The New York Telephone Co. an- 200 ohms to 7.5 megohms ... rated at % watt, 1sfó" nounced the opening of their bell- diameter, 74 " deep. Ask your distributor for full boy radio signaling service covering details about the new fashion in controls -Model Binghamton, Endicott, Johnson and Radiohms. an area surrounding these cities. The TT system has also been put into use in areas around Columbus, Ohio, and THE ELECTRONICS DIVISION OF GLOBE-UNION INC. Allentown-Bethlehem, Pa., the com- 922L EAST KEEFE AVENUE MILWAUKEE 1, WISCONSIN pany reported. CENTRALAB CANADA LIMITED -AJAX, ONTARIO A person subscribing to the service carries a small (7 %- ounce) transis- tor receiver which buzzes when he is ELECTRONIC VARIABLE CERAMIC wanted on the phone. On hearing the PACKAGED ELECTRONIC CIRCUITS ENGINEERED CERAMICS buzz, he can then call his home, io RADIO-ELECTRONICS

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www.americanradiohistory.com office or other contact from the near- STEREO QUALITY SOARS TO NEW HEIGHTS... est telephone. The telephone company said the Presenting the cost of installing the Bellboy equip- ment was more than $100,000. It can handle a maximum of about 3,000 re- finest ceramic stereo cartridge ceivers. Customers are charged $15 a month if one receiver is used. A second receiver costs $12.50 a month. The rate is for a maximum of 80 sig- ç\ nals a month. De Forest Award to N.M. Student Dwight Jaeger, 17, a Los Alamos, N.M. high school student, was awarded a $1,000 de Forest Schol- arship awarded annually by the Western Electronic Show and Con- vention (WESCON). Jaeger's ex- periment, which was displayed at the Future Engineers Show (a fea- ture of WESCON), was called

THE "PROFESSIONAL QUALITY" 9T! "Gravitational Pit" and simulated A -B to Now, the ceramic cartridge proved in independent listening tests the gravitational pull of satellites perform as well as the highest- priced "professional" types. It's Sonotone's as they orbit around the earth. revolutionary new 9T. So superior, you can expect faithful reproduction Dr. de Forest, at the time inva- from the most robust musical passages to the most subtle overtones. lided at his Hollywood home, sent a message to be given to the recipient Sonotone's new 9T series stereo cartridge: of this year's and future awards. GUARANTEES performance equal to car- tionary new needle design with instant Second place in the awards, a $600 tridges costing up to 3 times as much - "snap -in, snap -out" replacement needle scholarship, was given to Donald as proven in A -B listening tests. feature and built -in jewel tip protector. Shapero, a student at Cubberly High, Palo Alto, his work on "Preces- incredibly flat for GUARANTEES highest compliance -al- ELIMINATES distortion - sion Magnetrometry." Third place, response of ± 1 db from 20 to 17,000 lows major reduction of tracking force. a $400 scholarship, went to Melvin cps -cuts listening fatigue. GUARANTEES more than adequate chan- Rosowski of Clayton Valley High -up recent nel separation. ELIMINATES dust pile -at School, Concord, Calif., for an ex- trade show the 9T ran 4 straight hours, periment called "Cloud Chamber Re- GUARANTEES crisp definition. collected no dust. search." GUARANTEES superior, more compact ELIMINATES most record groove noise Fourth place, a $300 scholarship, mechanical design -including revolu- or hiss -no "needle talk ". was awarded to Edward Longe of Santa Barbara High for "Gaseous Imagine, the 9T boasts all these "professional" features ...yet sells for Discharge Phenomenon," and fifth less than half the price of the least expensive "professional" cartridge. place, a $200 scholarship, went to increase sales and profits Steve Walther of Punahou School, Simplify your inventory...cut call-backs- - Honolulu, for a display titled "See- with Sonotone's great new 9T cartridge... unsurpassed for performance ing with Sound." -and for value. Booster Operators Cooperate

. . . . . PRICE: 9T-S. . .$16.50 9T-S77 $16.50 9T-SD. $19.50 LIST of meetings in (0.7 -mil and (Two 0.7 -mil (Sapphire - Results of a series 3 -mil sapphires) sapphires) Diamond) the United States Northwest to ex- plain the new FCC booster rules to booster operators have been excel- lent, according to engineer Mclvor Parker of the FCC. The long- banned boosters are permitted to go into legal operation, provided their sta- SonotoneELECTRONIC APPLICATIONS DIVISION, ELMSFORD, N. Y. DEPT. C2 -I10 tions meet FCC requirements. The IN CANADA, CONTACT ATLAS RADIO CORP., LTD., TORONTO chief requirement is that they create LEADING MAKERS OF no harmful interference to other services, including other TV stations. Booster operators queried the FCC l representatives on a number of sub- r¿ ('i¡Ir jects, the most commonly asked ques-

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12 RADIO -ELECTRONICS

www.americanradiohistory.com What Does F.C.C. Mean To You?

What is the F. C. C.? not the general practice.) The first class radio- The Grantham course is designed specifically F. C. C. stands for Federal telephone examination consists of F. C. C. Ele- to prepare you to pass Communications ment IV. It is mostly FCC examinations. All Commission. This is an agency of the Federal technical covering ad- the instruction is presented with the FCC exami- Government, created by Congress vanced radiotelephone theory and basic tele- nations in mind. In to regulate vision theory. This every lesson test and pre - all and radio communication and radio and examination covers generally examination you are given constant practice in television broadcasting in the the same subject matter as the second class ex- answering FCC -type United States. amination, but the questions, presented in the questions are more difficult same manner as the questions you sill have to What is an F. C.C. Operator License? and involve more mathematics. answer on your FCC examinations. The F. C. C. requires that only qualified per- Which License Qualifies sons be allowed to install, maintain, and operate for Which Jobs? electronic communications equipment, including The THIRD CLASS radiotelephone license is Why Choose Grantham Training? of value radio and television broadcast transmitters. To primarily in that it qualifies you to take The Grantham Communications Electronics determine who is qualified to take on such re- the second class examination. The scope of Course sponsibility, authority Covered is planned primarily to lead to an F.C.C. the F. C. C. gives technical exami- by a third class license is license, but it does this by TEACHING elec- nations. Operator licenses are awarded to those extremely limited. tronics. who pass The SECOND This course can prepare yens quickly to these examinations. There are different CLASS radiotelephone license pass F. C. C. examinations because it presents types and classes of operator licenses, based on qualifies you to install, maintain, and operate the most all radiotelephone the necessary principles of electronics in a type and difficulty of the examination passed. equipment except com- simple "easy to grasp' manner. Each new idea mercial broadcast station equipment. is tied in What are the The FIRST with familiar ideas. Each new principle Different Types CLASS radiotelephone license is presented first in simple, everyday language. of Operator Licenses? qualifies you to install, maintain, and operate Then after you understand the every type of radiotelephone equipment (except "what and why" The F. C. C. grants three different of a certain principle, you are taught the tech- types (or amateur, of course) including all radio and tele- nical language groups) of operator licenses - commercial radio - vision stations in the United associated with that principle. telePHONE, commercial radioteleGRAPH, States, and in its You learn more electronics in less time, because and Territories and Possessions. This is the highest we make the subject amateur. class of radiotelephone license available. easy and interesting. COMMERCIAL RADIOTELEPHONE oper- ator licenses are those required of technicians How Long Does it Take to Prepare and engineers responsible for the proper opera- Is the Grantham Course a "Memory Course "? tion of electronic for F. C. C. Exams? equipment involved in the No doubt you've heard rumors transmission of voice, music, or pictures. For The time required to prepare for FCC exami- about "mem- example, nations ory courses" or "cram courses" offering "all the a person who installs or maintains two- naturally varies with the individual, de- exact FCC questions ". way mobile radio systems or radio and television pending on his background and aptitude. Grant- Ask anyone who has an broadcast ham training FCC license if the necessary materia_ can be equipment most hold a radiotele- prepares the student to pass FCC memorized. Even if you PHONE license. (A knowledge of Morse code exams in a minimum of time. had the exact exam NOT required is questions and answers, it would be mach more to obtain such a license.) difficult to memorize COMMERCIAL RADIOTELEGRAPH opera- In the Grantham correspondence course, the this "meaningless" mate- tor licenses average beginner rial than to learn to understand the subject. are those required of the operators should prepare for his .second Choose the school teaches and maintenance men working with communica- class radiotelephone license after from 200 to that you to thoroughly 250 understand- choose Grantham School of Elec- tions equipment which involves the use of Morse hours of study. This same student should tronics. code. For example, a radio operator on board a then prepare for his first class license in approxi- merchant ship must hold a radioteleGRAPH mately 75 additional hours of study. license. (The ability to send In the Grantham resident course, the and receive Morse time Is the Grantham Course is required to obtain such a license.) normally required to complete the course and Merely a AMATEUR operator licenses are those re- get your license is as follows: "Coaching Service "? quired of radio "hams " - people who are radio In the DAY course (5 days a week) you hobbyists should Some schools and individuals offer a "coach- and experimenters. (A knowledge of get your second class license at the end of the ing service" in FCC license Morse code is necessary to be a preparation. The "ham ".) first 9 weeks of classes, and your first class weakness of the "coaching service" method is license at the end of 3 additional weeks of What are the Different that it presumes the student already has a know- Classes of classes. This makes a total of 12 weeks (just a ledge of technical radio and appmaehes the RadiotelePHONE licenses? little less than 3 months) required to cover the subject on a "question and answer" basis. On whole course. from "scratch" first Each type (or group) of license is divided into through class. the other hand, the Grantham course "begins at different classes. There are three classes of radio- In the EVENING course (3 nights a week) the beginning" and progresses in logical order telephone licenses, as follows: you should get your second class license at the from one point to another. Every subject is (1) Third Class Radiotelephone License. No end of the 15th week of classes and your first covered simply and in detail. The emphasis is on previous license or on- the -job experience is re- class license at the end of 5 additional weeks of making the subject easy to understand. With quired to qualify for the examination for this classes. This makes a total of less than 5 months each lesson, you receive an FCC -type test so you license. The examination consists of F.C.C. Ele- required to cover the whole course, from "scratch" can discover daily just which points you do not ments I and II covering radio laws, F.C.C. through first class, in the evening course. understand and clear them up as you go along. regulations, and basic operating practices. (2) Second Class Radiotelephone License. No HERE'S PROOF that Grantham Students prepare for F.C.C. examinations in a minimum of time. Here on- the -job experience is required for this exami- is a list of a few of our recent graduates, the class of license they got, and how nation. However, long it took them: the applicant must have License Weeks already passed examination Elements I and II. Neil W. Michel, 402 E. Jefferson, Owensville, Mo. 1st 12 The second class radiotelephone examination L. Gordon Combs, consists RR#3, Box 279A, Hemet, Calif. 1st 11 of F. C. C. Element III. It is mostly Daniel A. Ruch, Station KVOZ, Box 1498, Laredo, Texas technical and covers basic radiotelephone theory 1st 12 George H. Sanderson, 1281/. W. 4th Street, Marysville, Ohio 1st 8 (including electrical calculations), vacuum tubes, Donald F. Teneych, 58 Brighton Road, Worcester, transistors, , oscillators, power supplies, N. Y. 1st 12 Richard Scherzer, Apt. 5, 1175 S. Franklin Ave., Los Angeles, Calif. 1st 13 amplitude modulation, frequency modulation, Jerry Miller, P. O. Box 1253, Charleston, West Virginia measuring instruments, transmitters, receivers, 1st 11 David M. Tarter, 1174 Hilltop Road, Kansas City 4, Kansas 1st 12 antennas and transmission lines, etc. Verne S. Nlelton, Jr., 1014 (3) First Canyon Road, Santa Fe, New Mexico 1st 8 Class Radiotelephone License. No Gerald T. Bullock, 613 Keefer Place, NW, Washington, D. on-the-job experience is required to qualify for C. 1st 12 this examination. However, the applicant most Resident Classes Offered at Four Locations have already passed examination Elements I, II, To better serve our many students throughout the nation, Grantham School of Electronics maintains and III. (If the applicant wishes, he may take four separate schools all four - located in Hollywood, Seattle. Kansas City, and Washington, D.C- -all offering elements at the same sitting, but this is the same resident courses in F. C. C. license preparation. (Correspondence from Hollywood.) courses are conducted For further details concerning F.C.C. licenses and our training, send for our FREE booklet,

"Careers in Electronics ". Clip the coupon below and mail it to the School nearest you.

MAIL Get your First Class Commercial F.C.C. License Quickly COUPON TO SCHOOL NEAREST YOU by training at (Mail in envelope or paste on postal card) To: GRANTHAM SCHOOL OF ELECTRONICS

1505 N. Western 408 Marion 3123 Gillham Rd. 821 -t3th, 1VW GRANTHAM Hollywood Seattle Kansas City Washington Please send me your free booklet telling how I can get my com- mercial F.C.C. license quickly. I understand there is no obligation SCHOOL OF ELECTRONICS and no salesman will call.

1505 N. Western Ave. 408 Name _- Marion Street 3123 Gillham Road 821 19th Street, N.W. Age Hollywood 27, Calif. Seattle 4, Wash. Kansas City 9, Mo. Washington 6, D.C. Address (Phone: HO 7.7727) (Phone: MA 2-7227) (Phone: JE 1 -6320) (Phone: ST 3.3614) City -- _State

t I am interested in: [ Home Study, Seattle classes MAIL COUPON NOW -NO SALESMAN WILL CALL Hollywood classes, Kansas City classes, Washington classes NOVEMBER, 1960 13

www.americanradiohistory.com that the TV station's permission to RADIO TV HI -FI HAM BROADCASTING INDUSTRIAL LAB rebroadcast its signals must be ob- tained. The provision that boosters must be so designed that they can be turned off immediately -from a remote point if unattended-also RCA KITS came up for discussion. FOR VALUE, QUALITY AND PERFORMANCE! It is likely that many boosters will require additional equipment before they meet with FCC standards as to RCA WV -38A (K) quality of signal, according to engi- neer Parker. Some of the pictures, VOLT -OHM- MILLIAMETER he pointed out, were of such quality that one might get a headache ee 95 onlyL9 (includes batteries, probe and cable watching them. -on alligator clip, ground lead and clip, as- with slip Soon sembly and operating instructions) (available factory - Stereo Standards Coming wired and calibrated -only $43.95'1 A strong feeling that FM multi- plex stereo standards will be set by Exclusive features make this RCA VOM kit the buy of a life- the end of 1960 per- time! Extra 1 -volt and 0.25 volt (250 mv) ranges for wider the FCC before usage in transistor servicing -new handle clip accommodates vaded the New York High -Fidelity probes and test leads for extra carrying convenience. Assem- held in September. The bles in a breeze! Show early results of the field tests conducted FEATURING: ohms -divider network -protected easier -to- read scales extra -large 51/4 inch meter polarity reversal from Pittsburgh were to be filed with excellent frequency response full -wave bridge the FCC Oct. 28. According to Tele- low circuit loading standard dbm ranges. vision Digest, five of the systems SPECIFICATIONS: Input Resistance -20,000 ohms per volt on DC; 5,000 ohms per volt on AC that observers Accuracy -± 3% DC, -!- 5% AC (full scale) Regular Scales -2.5, 10, 50, 250, 1000, 5000 volts, AC tested gave results Frequency and DC; 50 xa 1, 10, 100, 500 ma, 10 amps (DC) Extra Scales -250 mv. and 1 volt (dc) considered "good stereo." Response-AC -flat from 10 cycles to 50 Kc (usable response at 500 Kc) Ohms -3 ranges: Rxl- (0.2,000 ohms); Rx100 (0- 200,000 ohms); Rx10,000 (0- 20,000,000 ohms) Dimensions -W. 51 ", H.67/a ", D. 31/2" Knee Noise Signals Arthritis Sound patterns from the knee joints indicate rheumatoid condi- RCA WO -33A (K) tions, states Dr. Herbert Fisher of Ohio State University. Speaking be- 3 -INCH OSCILLOSCOPE fore the International Congress of 79Q 95' Physical Medicine at Washington only (complete with Low -Cap, Direct input recently, Dr. Fisher reported on rec- Probe and Cable) (also available factory -wired and cali- ords made of 75 subjects, of whom brated -only $129.95') 25 were patients with rheumatoid The first 'scope kit with "get -up- and -go!" Use it for practically involvements and 25 had been diag- everything -video servicing, audio and ultrasonic equipment, low nosed as suffering from degener- level audio servicing of pickups, mikes, pre -amps, radios and amplifiers, troubleshooting ham radio, hi -fi equipment, etc. -and ative arthritis. you can take it with you, on the job, anywhere! "Normal knees produce a rela- FEATURING: voltage -calibrated frequency- compensated, 3 to 1 tively regular pattern," he said. "In step attenuator scaled graph screen and calibrating voltage the pat- source for direct reading of peak -to -peak voltages "plus - rheumatoid arthritis, entire minus" internal sync...holds sync up to 4.5 Mc shielded in- tern is distorted, while in degener- put cable with low capacitance probe included weighs only 14 are high pounds includes built in bracket to hold power cord and cables. ative joint disease, there amplitude spikes superimposed on a SPECIFICATIONS: Vertical Amplifier (Narrow Band Position)- Sensitivity, 3 rms mv/inch; Bandwidth, within -3 db, 20 cps to 150 Kc Vertical Amplifier (Wide Band Position)- Sensitivity, 100 rms mv/ normal pattern." inch; Bandwidth, within -3db, 5.5 cps to 5.5 Mc Vertical Input Impedance -At Low -Cap cable input...10 megohms, 10 µµf (approx.); At Direct -cable input...1 megohm, 90 µµf (approx.) Sweep TV's Circuit -Sawtooth Range, 15 cps to 75 Kc; Sync, external, internal; Line Sweep, 160° adjustable Japanese Coming phase. Television receivers from Japan, now being seen in a few American stores, are expected in quantity for the Christmas trade, according to RCA WV -77E (K) Television Digest. Those reaching the counters first were 8 -inch units, VOLTOH MYST some portable and some ac- operated. /I 995' Contrary to previous experience with only$L9 (also available factory-wired and calibrated small -screen sets, sales have been only $43.95') good, according to the few dealers who have handled them. Sets were Think of It -an RCA VoltOhmyst Kit at this low, low price! You get A 19 receiver famous RCA accuracy and dependability, plus the easiest to assem- selling at $100. -inch ble kit you've ever seen! was expected by the beginning of FEATURING: ohms -divider network protected by fuse ultra -slim this month, to sell for something probes and flexible leads sleeve attachment on handle stores less than $200, and a 23 -inch set probes, leads, power cord separate 11/2 volts rms and 4 volts peak - to -peak scales for accuracy on -low ac measurements front -panel early in 1961. lettering acid -etched. SPECIFICATIONS: Measures: DC Volts -0.02 volt to 1500 volts in 7 Elevator + TV = Safety over- overlapping ranges; AC Volts (RMS) -0.1 volt to 1500 volts in 7 A closed -circuit television system lapping ranges; AC Volts (peak -to- peak) -0.2 volt to 4000 volts in 7 overlapping ranges; Resistance - from 0.2 ohm to 1000 megohms in 7 overlapping ranges. Zero -center indication for discriminator has been installed at the Ansonia alignment Accuracy-at 3% of full scale on dc ranges; ± 5% of full scale on ac ranges Fre- residential hotel in New York City quency Response-flat within ± 5%, from 40 cycles to 5 Mc on the 1.5, 5, and 15 -volt rms ranges and the 4, 14, and 40 -volt peak -to -peak ranges DC Input Resistance -standard 11 megohms (1 megohm solely for the purpose of observing a in probe). 'User Price (Optional) self -service elevator. Users of oper- atorless elevators are particularly See them all at your local RCA Test Equipment Distributor! vulnerable to robbery and attack. To OF AMERICA protect them, a remote -controlled, RADIO CORPORATION 10 -lb vidicon camera is mounted on ELECTRON TUBE DIVISION HARRISON, N.J. top of the elevator, with a special (Continued on page 20) -ELECTRONICS 14 RADIO

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RTS' Membership in Business Systems, Letterheads, The Association of Home Study Schools Calling Cards and Much More! is your assurance of Nare ta Say. Reliability, Integrity and Here's What Two of Many Business Plan Shoo nes Quality of Training. This business takes in between The school lives up to its $1500 and $2000 a month. I've promises 100 %. RTS does nct OC1ATIp had to hire help to keep up lose interest in its students once ccrryi o on with it they graduate. r CULLEN W. IRBY HAROLD R. STANLAKE Át4 Z.L'+'.4^+.BS Jd Corpus Christi, Texas Perry, Michigan ,._ min Rush J.I.z1j4111110 RADIO TELEVISION TRAINING SCHOCL, Dept. RE -110 Coupon 815 E. Rosecrons Ave. Los Angeles 59, Calif.. RADIO -TELEVISION Rush me full information by return mail. (Please Print) TRAINING SCHOOL NAME AGE _ 815 E ROSECRANS AVENUE FREE LOS ANGELES 59, CALIFORNIA STREET L 101D Est. 1922 FACTS! CITY ZONE _STATE I_,,;, ° Ijl!! SMAN WILL CALL ON YOU!

NOVEMBER, 1960 15

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because because 50 per cent of all TV sets made in the as JFD Exact Replacement Specialists, last 4 years are portables- sending service- dealers can get out of the un- more antenna replacement business to profitable "rabbit -ear" business -earn service -dealers every day. a profit on the antenna sale (at full mark -up) and on the installation. because because with the JFD PA500 and PA515 Exact with JFD guides, streamers, and sales Replacement Kits, dealers are ready helps, service -dealers get the merchan- and able to service 90% of antenna re- dising know -how that nets them a placements for portables and tote -ables. bigger slice of the 3,500,000 dollar portable antenna replacement market. :VOW IS THE TIME TO WRITE JFD OR ASK YOUR JFD DISTRIBUTOR FOR YOUR EXACT REPLACEMENT PROFIT PLAN PORTFOLIO!

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www.americanradiohistory.com (Continued from page 14) wide -angle lens looking through an opening in the top of the cab. A 24- inch monitor is set so that it can be Biggest Soldering Gun viewed from any part of the lobby. Two 17 -inch monitors are placed at opposite ends of the 16 -foot main desk so that they will be in direct view of the desk clerk at all times. Value on CALENDAR OF EVENTS the on in market! Techniques Conference Electronic Medi- cine and Biology, Oct. 31 -Nov. 2, Sheraton Park Hotel, Washington, D.C.

IRE -EIA Radio Fall Meeting, Oct. 31 -Nov. 2, Syracuse Hotel, Syracuse, N.Y. MODEL 8100B Conference on Magnetism & Magnetic Mate- rials, Nov. 14-17, New Yorker Hotel, New York, N. Y. Mid -America Electronics Conference (MAE- CON), Nov. 15-16, Muehlebach Hotel, Kansas City, Mo. Northeast Research & Engineering Meeting (NEREM), Nov. 15 -17, Commonwealth Armory and Sheraton Plaza Hotel, Boston, Mass. Northwest Hi -Fi Show, Nov. 25 -27, Leamington Hotel, Minneapolis, Minn. EIA Winter Conference, Nov. 29 -Dec. I, Fair- mont Hotel, San Francisco, Calif. and new Third Annual Futuronics Exposition, Nov. 30-, Dec. 2, Roosevelt Raceway Exhibit Hall, West- low price from bury, N. Y.

Vehicular Communications Meeting, Dec. 1 -2, Sheraton Hotel, Philadelphia, Pa. URSI -IRE Fall Meeting, Dec. 12 -14, NBS Boulder Laboratories, Boulder, Colo. Eastern Joint Computer Conference, Dec. í3- IS, New Yorker Hotel and Manhattan Center, N.Y. Radio Signals from Saturn The Navy reports receiving "the first conclusive signals" from the planet Saturn. They were picked up by scientists at the University of Michigan, using that university's 85- foot radio telescope. This may make possible a study of the temperature and density of Saturn's rings, and of the distribution of gases in its atmosphere. Signals were also picked up from a nebula so distant that the radio waves took 3,000 years to reach the receiving antenna. World TV's up to 94 Million The number of TV receivers in the world took a more than 10% jump during the 12 months preced- ing Aug. 1, 1960, to reach nearly Check these advanced features: 94,000,000, reports Television Digest. TV stations are now operating in 66 New Long -Life Wellertip- Utilizes copper for superior countries, with a total of 1,383 sta- heat transfer, plus iron -plating for rigidity and long life. tions on the air in foreign countries, (plus 570 in the United States). Copper conducts heat 5 times faster than permits steel, First of the foreign countries in TV operation at lower temperature, prevents damage to com- set ownership is Britain, with 10,- ponents. Long reach for easier use in difficult places. 900,000 sets, followed by Japan with 5,000,000, then by West Germany and 100 watts -single heat Russia, with over 4,000,000 each. Tip heats instantly when is trigger pulled -no waiting Electrons Weld Metals Prefocused spotlight illuminates work, eliminates shadows An electron gun is being used to New compact, streamlined design with rugged housing weld molybdenum alloys and pure Perfect balance for greatest soldering accuracy tungsten, according to Republic Aviation Corp. The metals are con- Guaranteed for 1 year -UL approved sidered very useful for space- vehicle work because of their resistance to On sale now at your Electronic Parts Distributor high temperatures. A narrow beam of electrons from Send for Weller Gun Bulletin the gun raises the metal's tempera- ture to the 6,000 °F needed for weld- 601 Stone's Crossing Rd. ing. The gun operates in a cylin- WELLER ELECTRIC CORP Easton, Pa. drical vacuum chamber that allows contamination -free welds. END

20 RADIO-ELECTRONICS

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A versatile economy priced tube tester A multiple- socket tube tester A CRT tester - Checks quality (emission, shorts and TESTS REPAIRS REACTIVATES all reactivator ,- A 20,000 ohms per vont VOM and ca- gas) of over 700 tube types. including the BLACK and WHITE and all COLOR picture tubes pacity tester ALL COMBINED IN ONE COMPACT UNIT! newest series- string TV tubes, OZ4s, gas l l.sTS ... emission. inter -clement leakage and -fi foreign Checks AS A TUF TESTER ... will check emission, inter - regulators, hi and tubes life expectancy REPAIRS ... shorts and open element leak: .:c and gas content of over 700 tube types each section of multi -purpose tubes elements REACTIVATES ... "weak tubes with AS A CRT TESTER-REACTIVATOR test, repair Easy-to -read 3 color meter scales 17 long a controlled high voltage pulse (reactivation is and reactivate all black and white and all color picture lasting phosphor bronze tube sockets seen and controlled on the emter as it takes place) Positively cannot become obsolete. New tubes AS A VOM AND CAPACITY TESTER .. . Tests the red, green and blue sections of oolor sensitivity is 20.000 ohms per volt /DC and 5000 ohms tube listing furnished periodically to all tubes separately Also provides the newer 2.35 registered owners Sturdy -gray hammer - per volt /AC . Capacity range: .001 mfd. to 80 mfd. and 8.4 filament voltages Unbreakable: mirror Unbreakable mirror for TV adjustments inside detach- tone steel case Size: 9x 81/2 x 2 3/4". for TV adjustments inside detachable rover able cover Handsome wood carrying case KIT - $3195 WIRED - $9(]95 Handsome wood carrying case Size, 171/2 x 13t /e x 41/2", Dealer Net $9975 Dealer Net Dealer Net ..1 Size 11 x 9' : x 4t/ ". Dealer Net $ 494995

SOLD ONLY THROUGH PARTS DISTRISU ORS oralamlis o... 1YtMIIKi. ° The instruction manual for ary in- Cannot become strument shown is available upon re- obsolete as new FREE tube types arc quest ... use coupon below introduced! Model 201 -F MERCURY ELECTRONICS CORP. (floor model) 77 Searing Avenue, Mineola, N. Y. E -11 Dealer Model 700 Model 1.1 Net Please send ¡ Model 500 Model ODO me instruction 1 ED Same specifications as the Tube tester has same specifica- $15850 manuals of the . Model 400 Model '32 -P Model 101 Also tests picture tions as Model 102 -P Tester test instruments ` Model 600 Model 1)2 -C tubes, all diodes, rectifiers, is removable Extra storage Model 201 -C I have checked. J fuses. pilot lamps Unbreak- compartment under tester (counter Model 300 Model : 31 able steel mirror for TV Drawer for tools and test leads model) adjustments inside detachable Unbreakable mirror mounted Dealer Name cover Handsome wood carry- under tester case for Net ing case. TV adjustments. $7450 Dealer Na $5950 Dealer Net ` $10950 Address 77 AVENUE L.City State MERCURY ELECTRONICS CORP. West Coast Office: . Victory Blvd., Burbank, Calif. NOVEMBER, 1960 21

www.americanradiohistory.com Let these 2 Ghirardi manuals teach you to REPAIR ANY TELEVISION RECEIVER made! SAVE S2.00! OR RADIO ever A. GHIRARDI Make your service library complete! Get both these Let these two famous training books teach book is co- authored by A. A. Ghirardi whose famous Ghirardi books at you to handle all types of AM, FM and TV radio -electronics training guides have, for a saving of $2.00 under service jobs by approved professional meth - more than 25 years, been more widely used the regular price. See ods-and watch your efficiency and earnings for military, school and home study training MONEY - SAVING COMBI soar! Almost 1500 pages and over 800 clear than any other books of their types. Books NATION OFFER in coupon. pictures and diagrams explain EVERY troubleshooting and repair operation as clear- are sold separately at prices indicated -or ly as A -B -C. No needless mathematics. No you save $2.00 by buying them both. Use cou- involved theory. You get straight-f rom-the- pon or order from Dept. RE -110, Technical shoulder training of the type that teaches you Div., Holt, Rinehart and Winston, Inc., 383 to do the best work in the shortest time. Each Madison Ave., New York 17, N.Y. RADIO & TV CIRCUITRY and OPERATION Learn about circuits ... and watch service headaches disappear You can repair ANY radio, TV or other electronic basic modern circuits and their variations. Finally it equipment lots easier, faster and better when you're shows what troubles to look for and how to eliminate fully familiar with its circuits and know just why and useless service testing and guesswork. Throughout, it how each one works . . . and that's exactly the kind of gives you the above -average training that takes the specialized training you get in Ghirardi's 669 -page headaches" out of trouble- shooting -the kind that fits Radio & TV CIRCUITRY AND OPERATION train- you for the best -paid servicing jobs. Contains 417 clear ing guide. First it gives a complete understanding of illustrations. Sold .s,'parar,'ty for A9.00-or s' lit11EY -S III V0 COMBINATION OF'F'ER. RADIO & TV TROUBLESHOOTING and REPAIR Complete training in modern service methods Radio & TV TROUBLESHOOTING AND REPAIR methods and shortcuts; or to find fast answers to prob- is a complete 822-page guide to professional service lems. You learn troubleshooting of all types from methods . the kind that help you handle jobs faster, "static" tests to dynamic signal tracing methods. Step - more profitably. For beginners, this giant book with its by -step charts demonstrate exactly what to look for and 417 clear illustrations is an easily understood course in how to look. A big television section is a down -to -earth locating troubles fast and fixing them right. For experi- guide to all types of TV service procedures. Read it enced servicemen, it is an ideal way to develop better Ill days at our risk! Sold separately for $10.00 or save $2.00 on MONEY- SAVING COMBINATION OFFER.

Cut Radio -TV Test Now! FIX ANY DON'T THROW OLD RADIOS AWAY! Time IN HALF! ELECTRIC MOTOR Here's the data you need Handle ANY ¡ob to fix old sets in a ¡iffy! In modern electronic work from minor Just look up the how-to - repairs to do-it data on that old radio it's what you know about complete you want to fix. using instruments that rewinding Four times out of 5, this really counts! 560 Pages-Over 900 giant, 3Va- pound, 744 -page how- to -do -it pictures Ghirardi RADIO TROU- HAND - It train Cur BLESHOOTER'S pays to BOOK tells what is likely to This new 316-page BASIC something different l ELECTRONIC TEST PRO- ELECTRIC MO'I'Olt be causing the trouble . . CEDURES manual with its Itt':I'.ti It is a complete shows how to fix it. No use- guide that helps Von less testing. No wasted time. more than 190 illustrations, pat- cash in on this t .1. Using it, even beginners can tern photos and procedure dia- rapidly grim ing Il.'.'I Shows sti i, easily fix old sets which grams teaches you to test any lists to handle all Covers every might otherwise be thrown circuit, equipment or component pair sold. model made by away because service infor- complete pelt inding 202 mfrs. from in a fraction of the usual time. mation is lacking. With a prod halls : \N1 AI 1925 to 1942 few ample repairs. most of Iu brief, it is a complete course Dl' motor or gtatera lur in coalmen use Crum thc-.l Id sets can be made in professional instrument testing techniques! fract i1ual horsepower to operate perfectly fur years to cone. Covers different ways of doing jobs. For instance, to St industrial too- you learn to check for distortion by the 'scope, TRAIN FOR BETTER THE ONLY GUIDE OF ITS KIND! binding brings tt:st and rejection wave PAY IN A FIELD filter, harmonic distortion meter, THAT ISN'T CROWDED! related how- to -do -it Cuts service time in half! analyzer or oscillator methods. You learn to meas- diagrams sirle by side Included are eomouat trouble symptom. :rid their SO thud ,111 Irani fast, easily and right. Fvery job is retin'rnes for over 4,4011 models of old haute, auto ure resistance a meter. a volt- with current explained se clearly you can hardly fail to understand radios and record changers. Airline, Apex, Arvin, ammeter. voltmeter, ohmmeter, or via the bridge it. Over 125.000 copies in use in umtot repair .hops. Atwater Kent, Belmont, Bosch, Brunswick, Clarion, i osley, G- E. Knister, Majestic, method -and so on through all types of testing. schools, and for borne study. Fully approved by repo Emerson, RarIa, specialists, unions and instructors. \II 111rota. l'hilco, Pilot, RCA, Silrertone, Sparton. Includes Current checks; measuring Power, It's the ideal tarok a het her you it ant to train lei suuutberg and dozens more. Includes hundreds of Capacitance, Resistance, AF, RF, Phase, Distor- good -pay motor repair job or simply want to lix imams pages of in, a limbic tube still component data, service short CHI,. tion & Modulation; testing Tubes and Semi- as a sideline or hobby! conductors; testing Amplifiers; checking Sensi- Order ELECTRIC MOTOR REPAIR in coupon. specify R -IDIO TROUBLESHOOTERS' HAND - tivity. RF Gain, Fidelity, AVC Voltage. etc. !'rice only $9.25. Rllllh io , oa pun. !'ripe only $10.00. 10-day trial. Even includes industrial electronic test procedures. Everything is really complete -and written to you can ttnderstanr! it! Price $8.00. Order BASIC ELECTRONIC TEST PROCEDURES In coupon.

22 RADIO -ELECTRONICS

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Alen uhw know burr tip a >r Get your COMMERCIAL OPERATORS LICENSE! oscilloscopes on all types of jobs don't guess about Train for radio's most fascinating, best paid jobs! troubleshooting and tough re- This famous hook makes it easy to EIGHT FCC examination alignment problems! They train for your FCC commercial license not just some of them. Re al- locate troubles in a jiffy, ad- as an operator aboard ship. in avia- most 2200 exam questions viers just them quickly and accu- tion, broadcasting, telecasting, etc. everything you'll need to -;t ost to rately -and this famous 346 - LICENSE MANUAL FOR RADIO pass your examination for let e r 2nd page manual teaches you the OPERATORS is a quick, easily un- methods they use. class radio -phone license hoadcr with derstood guide that covers ALL flying colors ! Price MODERN OSCILLO- $6.75. SCOPES AND THEIR 'Scope experts get USES gets right down tr, earth in telling you all about REPAIR ANY ELECTRICAL APPLIANCE! the big pay jobs! these versatile instruments and exactly how to use them. Save on repair bills ! ... Earn in your Spare Time! Particular attention is paid to AM. FiI, and TV This 370 -page ELECTRICAL APPLI- Troubleshooting charts quickly help you realignment procedures. Every detail of testing ANCE SERVICE MANUAL helps you locate troubles. Easy instructions guide you with 'scopes is explained from connecting the service practically any home electrical ap- in making repairs. Tells how to make your 'scope and setting its controls to adjusting com- pliance. Includes standard and automatic own low -cost test tools. Includes appliance ponents in the chassis being tested. Illustrated refinishing methods. An ideal guide for instructions teach you to analyze patterns. Even washers, ironers, toasters, ranges, cleaners, fixing your own apliances or for building includes (lata on quantitative measurements (as mixers, razors, clocks, motors, and many a profitable appliance repair business! $6.25. more. used in color TV servicing) and use of 'scopes in lab, industrial electronics and atomic work. 370 iltustratiouts. Price $8.00. ORDER Specify MODERN OSCILLOSCOPES .4ND THEIR TRY ANY BOOK 10 DAYS FREE! USES ,,, ,- ,,r,,,,, to order. NOW Dept. RE -110, Technical Division, Holt, Rinehart & Winston, Inc., 383 Madison Ave., New York 17, N. Y. S, nil New! Master Guide to TIME- hooks checker) for 10) day FREE examination at prices indicated plus )_restage. y: \ \'E! Send cash with order and we pay postage. Same 10 day retorts privilege with money refunded. SAVING TV SERVICE r- Check here for MONEY -SAVING SERV- E Check here for MONEY -SAVING Basic ICE COMBINATION on Ghirardi's Radio Training, of make or nndel this COMBINATION ON BASIC :Vnn,st regardless set & TV CIRCUITRY & OPERATION and ELECTRICITY AND BASIC ELECTRONICS. K t t l' Radio remarkable new 302 -page HAN DBO(t TV & TV TROUBLESHOOTING & RE- Price only 511.00 plus postage botk PAIR. Price for big TROUBLES helps you track down TV troubles only $17.00 for both (plus books. Regular price $12.50 -save Só'.50! from the symptoms they produce in the set itself : postage). Regular price $19.00 -save $2.00! screen intermittently dark: "blooming "; abnormal Check here contrast: "snore "; poor detail; to order INDIVIDUAL BOOKS sync troubles; Radio & TV CIRCUITRY & Basic Electronics sound troubles OPERATION L S 6.25 -and all the many other symp- $ 9.00 Modern Oscilloscopes Rodio & toms that indicate something & TV Receiver TROUBLE - Their Uses 8.00 SHOOTING and REPAIR is w rung. just turn to the 10.00 PIX -O -FIX TV Trouble Finder L Basic Electronic Test "Quick Trouble- Finder Guide" Guides, Nos. 1 and 2 3.00 inside the cover. Look up the Procedures 8.00 Electric License Manual for symptoms exhibited by the set Motor Repair 9.25 Radio Operators 6.75 you're working on. The HAND- '1 Radio Troubleshooter's Handbook Electrical Appliance BOOK then tells you just 10.00 Service Manual 6.25 LOOK! LISTEN! what to do how- Basic Electricity and to do it. Outlines O 6.25 Handbook of TV Troubles 7.50 Then follow this time-saving shortcuts. Eliminates guess- work. More than 150 test patterns, wave OUTSIDE easy guide! form and circuit U. S. A. illustrations explain test Add 500 to price of Name results, details and procedures. Printed each in large type book. Cash with and hound in sturdy varnished covers for use at the order, but money re- Address bench. All methods presented have been bench -tested by the author funded if books are re- through actual shopwork! Price $7.50. turned in 10 days. City, Zone, State Order II .4. DROOK OF TV TROUBLES in coupon. NOVEMBER, 1960 23

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www.americanradiohistory.com rCorrespondence

REPORT FROM A USER Dear Editor: I was very interested in "How to Obtain Faster Break -in" which ap- peared on page 137 of the March, 1960, issue. It showed how to remedy the problem of slow recovery in radio re- ceivers when the amateur throws his T -R switch from Transmit to Receive. I was having a terrific amount of

CH 8-30H REGT 8-1 25K- 50K BLEEDER

( FILTER 117 VAC CAPS)

SPST CONTACT OR = SW trouble with this problem and I thought I would give this idea a try. I was amazed at how perfectly the change in circuitry solved my problem. No matter how fast I flick my T -R switch, I don't get any of that annoying leftover signal WITH VOCALINE 4- CHANNEL COMMAIRE from the transmitter. Since I have made this change, a ED -21M BAND RADIO number of other hams in this area have CITIZENS made this modification too and all report equally perfect results. Also available in DANTE AMOROSE-K4IIW single channel J. Ranked first for model - Richmond, Va. Commaire [Thanks for the note of appreciation. ED -27M And for those readers who missed this dependability proven as the item we are reprinting the switching world's finest - performing class circuit here.-Editor] distance clarity D Citizens Band Radio! Only FOR TV TECHNICIANS $179.50 each, list. Dear Editor: The "Philadelphia Plan" announced Citizens band radio can be no more effec- in the August Technicians' News col - tive than the equipment you use! In fact, $189.50 worthy of comment. list. umn seems no judgment on the subject can be valid each, How large a portion of the whole- until one has heard the type of perform- saler's business is involved with the ance possible when properly engineered; over -the -counter cash sale? It can't be truly superior equipment is utilized. Example: the Vocaline Commaire ED- one unit that is unmatched by any other much or the wholesaler would not be 27M, the finest citizens band radio avail- in its class. willing to relinquish it and take on able anywhere today! The difference Specifications and features: Finished to the added burden of accounting and between Vocaline Commaire ED -27M pass U.S. Navy 500 hour salt spray test! making the "kickbacks" to the various and ordinary Citizens band radios can "Silent- Aire" squelch with exclusive service shops. Now, then, when this be as substantial as the difference noise suppression. Double conversion very small portion of the total volume between the two photos above. For dis- superheterodyne single crystal receiver - of business is divided between the indi- tance, reliability, flexibility and uniform accepted as the finest. Transistorized vidual service shops, how much have clarity on the entire 22 channel citizens power supply. 5 watts input - 3 watts band you have only to hear the Com- output. 6 and 12 VDC 115 VAC. Only you really gained? ... - Then the cost. The cost of the whole- maire to convince yourself that this is the 51/4 /a- x81/4 ". "x91 saler has already been mentioned, but now that you are demanding the retail Send complete literature to: profit you must bear the retail load, Name that of maintaining a retail stock over YOCAZI1VE and above your bench stock items. This COMPANY OF AMERICA Address 123 Coulter Street takes space and capital. It can't be Old Saybrook, Conn. City Zone State circumvented by telling the customer

26 RADIO -ELECTRONICS

www.americanradiohistory.com to come back later while you obtain the desired items. And what is the con- sumer's reaction to all this? He will certainly become incensed at you, the Build neighborhood service This Superb ¿PhéPì. shop, especially when he learns of the "kickback gim- mick" on top of the drastic increase in cost. The TV service industry in general Organ From Simple Kits and has never done much toward enhancing its customer relations in the past and this latest maneuver is not going to improve the situation. Why did the man take to trying to fix his own TV SAVE OVER 50 %! The Beautl-u1 in the first place if he felt that he was being treated fairly by his local service man? Consider the auto repair business. It CONSOLET-E has lived with this problem a long time. the only smai or- It succeeds by rendering service and gan with two full 6t- note keyboards and not through selling parts. The car owner 22 stops. Requires a can still buy his own parts and do his only 2' x 3'2" f oor own work if he so chooses. But he can space! Commexial usually get the work done better and value approximately $1600 or more Jet. quicker at the local garage. He goes LET US you save over 51% there. SEND YOU when you build tats The "Philadelphia Plan" certainly thril ling instrument ! typifies the type of thinking that has made the TV service industry "sick" in FREE the first place. MAJOR WILLIAM M. PRICE DETAILS Little Rork AFB, Ark. HOW TO ASSEMBLE A [Technicians! How do you feel about this ? -Editor] ELECTRONIC ORGAN DANGEROUS TEFLON IN SPARE TIME! Dear Editor: Referring to the article "Solder Re- moval Made Easy" on page 68 of the June issue. The use of Teflon tubing to pick up molten solder can be very dangerous since the decomposition prod- ucts are highly toxic. Above 200 °C, Teflon gives off fumes which, if inhaled, has caused polymer Give Your Family A Lifetime fume fever. Deaths have occurred when of Musical Joy granular or dispersion polymers were With A Magnificent Schober ELECTRONIC Organ! heated above 300 °C. Particles of Teflon must not be Now you can build the brilliant, full -range Send For Complete Details On Schober Organs and For Hi allowed to contaminate cigarettes and Schaber CONSOLETTE or the larger CONCERT -Fi Demonstration Record MOREL with simple hand tools. skills they must not be carried where con- No The coupon will bring you a handsome 16- are necessary to construct an instrument with page booklet in full tamination is possible. color describing Schober one of the finest reputations organs ill detail, plus articles THE GREAT on If someone were to apply this method among electronic organs. No how easy and rewarding it is to of solder removal with the use of a woodworking necessary con- CONGER T MODEL build your own organ meets speri fications of and how torch, it is possible that death could soles tonne completely assem- pleasant and quick it is to learn result. bled and finished. All you do is America n Guild to play the organ. In addition, LEE E. VANDERVEER assemble clearly marked elec- of Or ganists we have prepared an exciting Ludington, Mich. tronic parts guided by clear il- 10" hi -fi LP record demonstrat- lustrations and detailed step -by -step instruc- ing the full range of tones and voices avail- AUTHOR'S REPLY tions. Even teen -agers can assemble the able on the Schober, which you may have Dear Editor: Schober! You build from kits, as fast or as for only 82.00 (refunded when you order a slowly as you please... at home, in spare kit). Literature on the Schober is FREE! Mr. VanderVeer's comments concern- time with a small table serving as your There is nu obligation; no salesman will cal . ing toxic products of decomposition of entire work shop! Teflon are well known and do apply for Pay As You Build Your Organ; steady -state thermal conditions such as Mail This Coupon Start With As Little As $18.94! those obtained from heating a solder You may start building For FREE Literature joint with a torch. However, under your Schober at once transient with an investment of as little as $18.94. The and Hi -Fi Record thermal conditions such as musical instrument you assemble is as fine, Today! the application described in my article, and technically perfect, as a commercial appreciably higher temperatures can be organ built in a factory yet you save over The Schober Organ Corp., Dept. RE -8, tolerated without the danger of Teflon 50 on top -quality electronic parts, On 43 West 61st St.. New York 23, N. Y. 1 decomposition. The system described in high -priced labor, on usual retail store mark- Please send me FREE full -color booklet and l the article was developed for use in the up! In ynnr own home, with your own hands other literature on the Schober organs. removal of solder from terminal con- you build an organ with genuine pipe organ Please send me the 10" hi -fi Schober demon- ` stration record. I enclose tones in an infinite variety of $2.00 (refundable on l nections in complex miniature electronic tone colors receipt of my first kit order). assemblies, not in plumbing work. to bring into your home the full grandeur A of the Emperor of Instruments. torch of any kind is never You may Name used for this build the CONSOLETTE for your home, or you kind of work; only low- wattage solder- may want to build the great CONCERT Address l' ing irons. \TOOEL for home, church, school or theatre. There are other reasons why this You save 50% and more in either case. City Zone...State j NOVEMBER, 960 29

www.americanradiohistory.com application of Teflon tubing isn't dangerous: The end of the tube is not brought close to the solder joint until it is fluid advantage and the soldering iron removed. A high -volume vacuum pump guar- of using a antees adequate air flow to pick up the solder and insure quick chilling of the molten solder. If there is some decompo- sition of the end of the tube, the toxic PRECISION products are immediately picked up by Vthe the inrushing air and carried into the vacuum pump where they are trapped IL:EOP out. This technique has been used success- fully in many applications throughout in your high fidelity installation the electronics industry for more than 3 years without any reported difficulty. audio wave forms WILLIAM J. MCGUINNES Intricate N. can be reproduced accurately Rochelle Park, J. only by transducers of the DON'T TRY THIS! highest precision. Anything less Dear Editor: introduces sonic impurities The legitimate TV service dealers in which in minutes become our area operate under a hardship vaguely annoying and today. They're getting a black eye from ultimately intolerable. The the malpractices of a few jackleg and great advantage of precision back -alley shops and from customers in loudspeaker construction is who move here and then complain that lasting listening pleasure. their TV goes out more frequently than You will find that you it did at "home." feel satisfied when you live "Here" is Sarasota, Fla., a coastal JBL D130 with a precision instrument, 15" full -range town, and the heat, humidity and salt speaker with 4" voice coil and this can represent a air are all adverse factors. Even with decided economic advantage. a new set, a Sarasotan can expect more Precision also contributes TV breakdowns than he did in the to efficiency. High efficiency North. not only lowers your power For this reason, our service opera- requirements, but, more tion embraces two factors. We won't important, gives you superior accept for repair any set that is 8 to reproduction of transients, a 10 years old, because to do a good job more realistic dynamic range; on such a dog would involve the cus- and cleaner, smoother sound tomer in exorbitant costs and bring over the entire frequency cries of "gyp." spectrum. If you are installing Also, since customers are madly a system for someone else, adverse to "labor charges," we often your reputation as an expert submit an invoice which, instead of depends on how the system listing $1.50 for parts and $7.50 for JBL D123 sounds to the client six months, labor, lists $7.50 for parts and $1.50 12" full -range and even six years from now. for labor. That keeps the customers far speaker with 3" voice coil Play it safe; install JBL, choice happier than a small amount for parts of the conscientious technician. and a high labor charge. NAME WITHHELD Sarasota, Fla. [Your billing technique sounds nice, but can get you into trouble. What happens when the Better Business Bureau or a local newspaper comes around, traps you with a gimmicked set ; and discovers that you are charging for parts you didn't replace? That's the kind of billing that can put you out of JBL D208 business. Editor] 8" full -range JBL LE8 speaker with 2" voice coil 8" linear- efficiency PLEASE full -range speaker CORRECTION with 2" voice coil Dear Editor: In my article "Radio Waves and the third HIGH EFFICIENCY SPEAKERS LINEAR -EFFICIENCY SPEAKERS Life" (September issue), paragraph on page 45 states that the are characterized by excellent transient re. provide long linear cone excursion so that clean, of secre- sponse, strong impressions of immediacy and full bass can be generated in a relatively small field reduced the stimulation presence. Power requirements are low. For pre space. They can be mounted directly in a wall tion of digestive juices when atropine cision bass reproduction they require a bass re- or partition, but are usually mounted in an "in- had been injected. flex or exponential horn acoustical enclosure. finite baffle" type enclosure of minimum dimen- This is incorrect as was pointed out Voice coil: o.d. ratio of the highly efficient units sions. Power requirements for JBL Linear. shown above is 1:4, an exclusive JBL feature. Efficiency units are moderate because they are by Dr. Jarrett of Phoenix, Ariz. The built to the highest standards of precision. correct version is: The field reduced the inhibition of Write for complete catalog of JBL precision loudspeakers, precision digestive juices when these were in- high frequency units, and acoustical enclosures...Bulletin SC508. hibited by the drug atropine. Products of James B. Lansing Sound, Inc., are marketed by Tom JASKI JBL INTERNATIONAL, LOS ANGELES 39, CALIFORNIA San Mateo, Calif. END RADIO -ELECTRONICS 30

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By far the best professional VTVM value depth of interna modulation 3-50% by 400 in electronics; nobody but EICO brings cps Colpitts oscillator. Variable gain external you such outstanding instrument perform- modulation amplifier: only 3 volts needed for ance for so low a price! Calibration without 30% mod. Turret -mounted, slug -tuned coils removing from cabinet. Measure directly p-p for max. accuracy. Fine & Coarse (3 -step) RF voltage of complex & sine waves: 0 -4, 14, attenuators. RF output 100,000 uv, AF output 42, 140, 420, 1400, 4200. DC /RMS sine to 10 v. volts: 0 -1.5, 5, 15, 50, 150, 500, 1500 (up to 30,000 volts with HVP probe, & 250 mc Provides more ranges, greater ease and with PRF probe). Ohms: 0.2 chms to 1000 accuracy, and better performance than megs. 4r/z" meter, can't -burn -out circuit. 7 any competitive unit. Entirely electronic non -skip ranges on every function. Zero sweep circuit with accurately- biased incre- center. *Features EICO's exclusive UNI- PROBE: ductor for excellent linearity. Extremely flat your terrific time -saver, performs all func- RF output. Exceptional tuning accuracy. Hum tions: a half turn of probe -tip selects DC & leakage eliminated. 5 fundamental sweep or AC -Ohms! ranges: 3 -216 mc. Variable marker range: 2-75 mc in 3 fund. bands, har- ©An engineering achievemert unmatched 60 -225 mc on monic band. 4.5 mc in the industry! EICO- designed for labo- crystal marker osc., crystal supplied. Ext. provision. ratory precision and EICO- priced for lowest marker At- tenuators: Marker Size, RF Fire, RF Coarse cost. Features DC amplifiers. Flat from DC to (4 -step decade). Narrow range 4.5 mc, usable to 10 mc. Vert. Sens.: 25 mv/ phasing con- trol for accurate alignment. in.; input Z 3 megs; direct -coupled & push - pull PEAK -TO -PEAK throughout. 4 -step frequency- compen- Speedy, simple operation, unexcelled sated attenuator up to 1000:1. Sweep: O VTVM #232 & UNI -PROBE per- sensitivity and accuracy; superb elec- fectly linear 10 cps - 100 kc KIT $29.95 WIRED $49.95 (ext. cap. for trical and mechanical design. Tests all range to 1 cps). Pre -set TV V & H positions. receiving tubes (picture tubes with adapter), Auto sync limiter & amplifier Direct or C n -p -n and p -n -p transistors. Composite indi- coupling; balanced or unbalanced inputs; cation of Gm, Gp & peak emission. Simul- edge -lit engraved lucite screen with dimmer taneous of any control. selection one cf 4 combina- tions of 3 plate voltages, 3 screen voltages, More features and versatility, more 3 ranges of contiguously variable grid volt- range and accuracy than ie generators age (with 5% accurate pot.). Sensitive 200 costing three to four times as much. 150 kc ua meter. 10 six -position lever switches: to 435 mc with ONE generator in 6 fun- freepoint connect on of each tube pin. 10 t damental bands and 1 harmonic band! push- buttons: rapid insert of any tube ele- ±1.5% frequency accuracy. Colpitts RF ment in leakage test circuit. D rect reading - oscillator directly plate -modulated by K- of inter -element leakage in ohms. New gear - ae follower for improved modulation. Variable driven rollchart. CRA Adapter $4.50. 0o

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www.americanradiohistory.com Stereo Amplifier- Preamplifier HF81t

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birch. Kit advanced systematized engineering FM Tuner HFT90: Prewired, prealigned, tempera- HWD: 24" x 121/2" x 101/2 ". Unfinished Exclusive Walnut or mahogany. Kit Latest and finest quality parts ture- compensated "front end" is drift -free. Pre - $47.50. Wired $56.50. Exclusive "Beginner- Tested" easy step -by- wired exclusive precision eye -tronic® traveling $59.50. Wired $69.50. step instructions tuning indicator. Sensitivity: 1.5 uy for 20 db HFS1 Bookshelf Speaker System complete with Exclusive TRIPLE quality control quieting; 2.5 uy for 30 db quieting, full limiting factory -built cabinet. Jensen 8" woofer, match- Exclusive LIFETIME guarantee at nominal cost from 25 uv. IF bandwidth 260 kc at 6 db points. ing Jensen compression -driver exponential horn Both cathode follower & FM- multiplex stereo tweeter. Smooth clean bass; crisp extended IN STOCK Compare, then take home any EICO - outputs, prevent obsolescence. Very low distor- cps range. 8 ohms. HWD: 23" from 1500 highs. 70- 12,000 equipment right "off the shelf" - best buys in high fidelity kits." - tion. "One of the x 11" x 9 ". Kit $39.95. Wired $47.95 neighborhood EICO dealers throughout the U.S. *. Wired $65.95 *. budget terms. - AUDIOCRAFT. Kit $39.95 & Canada, most of whom offer cover, F.E.T. incl. HFS2 Omni -Directional Speaker System (not illus.) Cover $3.95. *Less for stereo" 11F81 Stereo Amplifier -Preamplifier selects, HWD: 36" x 151/4" x 111/2 ". "Fine - Tuner HFT94: Matches HFT 90. Selects "hi -fi" amplifies, controls any stereo source & feeds it AM MODERN HI -Fl. Completely factory- built. Mahog- wide (20-9000 cps @ -3 db) or weak- station -contained dual 14W amplifiers to a pair any or walnut $139.95. Blond $144.95. thru self narrow (20 -5000 cps @ -3 db) bandpass. Tuned of speakers. Provides 28W monophonically. Changer /Player: lam- RF stage for high selectivity & sensitivity. Pre- New Stereo /Mono Automatic Ganged level controls, separate balance control, "One of the best proof 4- speed, all record sizes, automatic changer for each cision eye- tronic® tuning. independent bass and treble controls -Fl SYSTEMS. Kit $39.95. Wired and auto /manual player. New extremely smooth, Williamson -type, push -pull available." -HI cartridge channel. Identical $65.95. Incl. cover & F.E.T. low distortion moisture -proof crystal EL84 power amplifiers. "Excellent " - SATURDAY with tonearm to eliminate renowned EICO designed integrally REVIEW. "Outstanding ... extremely versatile." FM /AM Tuner HFT92 combines mid -range resonances. Constant 4112 grams stylus ELECTRONICS WORLD. Kit $69.95. Wired HFT90 FM Tuner with excellent AM tuning facili- optimum to prevent groove flutter dis- - Incl. cover & force is $109.95. Incl. cover. ties. Kit $59.95. Wired $94.95. tortion. No hum, turntable attractions, acoustic HF85 Stereo Preamplifier: Complete master F.E.T. feedback, center -hole enlargement. Only 103/4" x -control unit, self -powered. AF.4 Economy Stereo Integrated Amplifier pro- 13". 1007S: 0.7 mil, 3 mil sapphire, $49.75. stereo preamplifier output. Distortion borders on unmeasurable. Level, bass, vides clean 4W per channel or 8W total Incl. F.E.T. and "Magnadaptor." $64.95. Incl. cover & F.E.T. treble controls independent for each channel Kit $38.95. Wired Furniture Wood Cabinet for tShown in optional or ganged for both channels. Inputs phono, HF12 Mono Integrated Amplifier (not illus.): Com- WE71: Unfinished Birch, $9.95'; Walnut or AM, FM, & FM- multiplex. One & hi -fi perform- tape head, mike, plete "front end" facilities true Mahogany, $13.95. each auxiliary A & B input in each channel. 25W peak. Kit $34.95. ance. 12W continuous, Wood Cabinet . . a bargain." HI -Fl -Shown in optional Furniture "Extreme flexibility - Wired $57.95. Incl. cover. l Walnut or REVIEW. Kit $39.95. Wired $64.95. Incl. cover. WE70: Unfinished Birch, $8.95; HFS3 3 -Way Speaker System Semi -Kit complete Mahogany, $12.50. New HF89 100 -Watt Stereo Power Amplifier: Dual with factory -built 3/4" veneered plywood (4 sides) 50W highest quality power amplifiers. 200W peak cabinet. Bellows- suspensiop, full -inch excursion power output. Uses superlative grain-oriented (22 cps res.) 8" mid -range speaker 12" woofer 33 -00 N. Blvd., L.I.C. 1, N. Y. C -Il steel output for undistorted re- with high internal damping cone for smooth re- EICO, sponse across the entire audio range at full sponse, 31/2" cone tweeter. 21/4 cu. ft. ducted - Show me how to SAVE 50% on easy- to-build Stereo Hi -Fi power, assuring utmost clarity on full orchestra port enclosure. System Q of 1/2 for smoothest top -quality Hi -Fi. Send FREE catalog, & organ. 60 db channel separation. I M distortion frequency & best transient response. 32- 14,000 Guide plus name of neighborhood FICO dealer. 0.5% at 100W; harmonic distortion less than 1% cps clean, useful response. 16 ohms impedance. Name from 20-20,000 cps within 1 db of 100W. Kit HWD: 263'4" x 137/4" x 141/4". Unfinished birch. $99.50. Wired $139.50. Kit $72.50. Wired $84.50. Walnut or mahogany. Address 11F87 70 -Watt Stereo Power Amplifier. Dual 35W Kit $87.50. Wired $99.50. Zone State power amplifiers identical circuit -wise to the HFS5 2 -Way Speaker System Semi -Kit complete City superb HF89, differing only in rating of the out- with factory -built %4" veneered plywood (4 sides) put transformers. IM distortion 1% at 70W; cabinet. Bellows- suspension, 5/e" excursion, 8" harmonic distortion less than 1% from 20-20,000 woofer (45 cps. res.), & 31/2" cone tweeter. 11/4" Listen to the EICO Hour, WABC -FM, N. Y. 95.5 MC, cpswithin 1 db of 70W.Kit $74.95.Wired$114.95. cu. ft. ducted -port enclosure. System Q of 1/2 for Mon: Fri., 7:15 -8 PM. smoothest freq. & best transient resp. 45- 14,000 11F86 28-Watt Stereo Power Amp. Flawless repro- 1960 by EICO, 33 -00 N. Blvd., L. I.C. 1, N.Y. duction at modest price.Kit$43.95. Wired$74.95. Cps clean, useful resp. 16 ohms. 32 RADIO -ELECTRONICS

www.americanradiohistory.com Radio -Electronics Hugo Gernsb -ck, Editor

FUTURE SPACE TRAFFIC

... Tens of Thousands of Spacecraft will Soon be Aloft . . .

S this is written (at the end of August), 34 space weather conditions such as cloud formation and cyclones, ice vehicles are in orbit. The United States accounts patrolling and hundreds of other activities. for 26, the Soviet Union 8. Still transmitting All space observatories will also be equipped with the data to earth are 10 -US 9, Soviet Union 1. The most modern and sensitive infrared receiving equipment. rest -i.e., 24 space vehicles -either through mechanical Even with present -day equipment, it would be possible to malfunction or for electronic reasons, are still gravitating detect a multitude of heat effects at a distance of 22,238 in space, voiceless and signal -less, silent. miles overhead, even through overcasts. In the future the This is the short and epic 3 -year record of man's first stationary space observatories will do vastly more refined excursion into space, above the earth's atmosphere, since the observing and detecting of many activities on the earth - advent of Sputnik I -the true start of the Space Age, on particularly for military purposes. Oct. 4, 1957. What of the future, immediate and distant? Also connected by cable to every floating observatory will Columbus and the intelligentsia of 1492 certainly never be a huge aluminized plastic ball or sphere from 750 to dreamt what the opening of the New World could mean to 1,000 feet in diameter. The three observatories, stationed mankind -riches beyond imagination, steamships that trans- equidistant around the earth 22,238 miles over the equator, port 3,000 people across the Atlantic in a little over 4 days will reflect from their spheres ALL electronic long -distance, (it took Columbus 70), speaking under and above the ocean, national and international communication traffic, be it radio, flying over it in 6 hours and less, seeing across the ocean TV, telegraph or telephone, or other signaling. Signals by television (Baird on Feb. 8, 1928). Certainly no one can be directly bounced from earth against the reflecting alive in 1492 would have had the temerity to predict such balls, then returned to earth. Others, to reach the anti- "arrant nonsense "! podes, will be relayed between the observatories, then trans- Likewise, we of 1960 are often prone to look at the con- mitted to their destination. quest of space now in the making as an enigma, wrapped By the time the observatories are in space by the end of in doubt and disbelief, that appears of little consequence this century, it is almost certain that all spacecraft. will be to humanity at large. propelled by atomic power. This will be true of satellites Let us then push aside the thick veils of the future and as well as interplanetary spaceships. examine some of the possible scientific predictions of the Won't there be many collisions in space between these Space Age. Remember always that space is a new and tens of thousands of spaceships, satellites, observatories and completely alien and harsh world, never visited by living dozens of other types of spacecraft? Not at all- certainly man before. many fewer than between the thousands of propeller and Extreme heat and cold, dozens of harmful radiations jet airplanes now crowding the air lanes. All present air many deadly, weightlessness, a - traffic moves in a thin space less than 50,000 feet thick. variety of gravitational Future space effects, meteorites and other matter flying at the traffic will be dispersed into millions of miles. rate of There could be tens of millions of over 10 miles a. second, a total vacuum -these spacecraft maneuvering are only a in space without fear collision. The few conditions in this new world never experienced by man. of only possible danger will come when thousands of space vehicles descend en ,masse Let us stay for a few moments with only one branch of space vehicles, the toward the earth to land. satellite type that circles the earth in Inasmuch as all landing orbit from 250 to thousands of miles craft must have permission to above. We mentioned alight, exactly as aircraft today, collisions will that at this moment there are 34. In be a rarity. time there will be This will even be more true than now, because future space- many thousands of every imaginable type. By the end of this century there will certainly craft will not require long landing strips. All space vehicles be more than 10,000 earth, of the future will descend vertically lunar and other planetary satellites of into rather small num- every description of bered spaces, many flights terminating on top city dozens of nations. Many will be for research, many for of sky- communication purposes. scrapers, just as helicopters do now. They will be of all sizes, from a Will not our communications spectrum few feet to thousands of feet in diameter. be severely over- Most will be loaded with all this tremendous traffic between earth automatic, highly sophisticated unmanned ones; others will and be manned. tens of thousands of satellites, observatories, spaceships to and from the planets? Hovering observatories will be "stationed" 22,238 miles Fortunately not. above the There is sufficient room in the radio- equator. Seen from the earth, they will appear frequency spectrum to accommodate stationary as they 300,000 simultaneous travel at about 6,882 miles per hour, which separate communications at a minimum. compares to the surface speed of 1,000 miles an hour at Incidentally, which the earth once thousands of interlunar and inter- revolves.* Equipped with light amplifiers, planetary spaceships are in transit, they probably three such observatories, spaced will not equidistant over the equator, communicate directly with the earth at all. There will be can directly view and photograph any part of any country an (except interplanetary communication center on the airless moon, the polar regions) and spot any activitiy such as its sole purpose being troop movements, intercontinental to clear all distant message traffic, missiles when launched, which then will be relayed to earth on special frequencies. Even communications between the various spaceships will *At an be via the moon altitude of 22,238 miles, the observatories must travel nearly 7 center, unless the spacecraft are near each times as fast as the earth's speed at the equator. other, which probably won't be too often. -H.G. NOVEMBER, 1960 33

www.americanradiohistory.com ELECTRO

By DR. BERNARD S. POST*

ELECTROMYOGRAPHY is an elec- tronic method of measuring and recording the electrical activity of muscles. It is a valuable diagnostic tool in the hands of a competent op- erator. Most often used in physical medicine, neurology, orthopedics and neurosurgery, it has many applications in other fields, including research. The high incidence of muscular and nervous - system injuries during World War II, and more recently during the Korean conflict, served to speed up the develop- ment of electromyographic techniques. A normal muscle at rest emits no detectable electric signal but in action or in certain abnormal states of the muscle (or of the nerve connected to it) waveforms are produced. The shape of these waves varies with the condition that causes them. For instance, a nor- mal muscle contraction will produce a tracing like that of Fig. 1 -b. The amplitude of the waveforms varies between approximately 100 and 1,500 µv, with a frequency of 5 to 30 per second or higher, depending on the intensity of the muscular contraction being measured. The average duration of the spike is about 5 to 10 milli- seconds. The waveform is bi- or tri- phasic in character. Other character- istic waveshapes are also shown in Fig. 1. Most are abnormal and are found in disease states or injuries. Electrodes The action potentials are picked up with a needle electrode which is pushed through the skin into the muscle being examined. Three types of needles are Fig. 1- Waveforms in use (Fig. 2). The first, a monopolar produced by: a- type, consists of a plain sewing needle normal muscle at passed through a cork and insulated rest; h- normal completely except at its very tip. Such muscle contract- ing, popping an electrode must be used with a refer- sounds; c- muscle ence electrode on the skin to complete with nerve supply the circuit. This reference electrode cut, crackling sets up numerous problems due to skin sounds; d - muscle current and the distance between elec- with nerve regenerat- trodes. The second and third types are ing, chugging sounds; hypodermic needles fitted with either e- muscle disease (My- one or two through the needle otonia), sounds like a bore and insulated from the needle dive bomber. shaft (and in the two -wire case, from each other). If one wire is used, it is called a single coaxial electrode. If two

*BS, MD, PGME of IRE. In charge of Electro- myography Laboratory, St. Johns Episcopal Hos- pital, Brooklyn, N.Y. Research Fellow in Physi- cal Medicine, Downstate Medical Center, Uni- versity State of New York. RADIO -ELECTRONICS www.americanradiohistory.com MYOGRAPHY Waveforms produced by contracting muscles are helpful in diagnosing muscle and nerve disorders

are used, it is referred to as a double coaxial electrode. Again the shaft of the needle is insulated except at its tip. The advantage of the coaxial elec- trode is that it makes it possible to contact individual muscle fibers, since the tip of the needle electrode is a complete circuit unit only a fraction of a millimeter in size. This is approx- imately equal to the size of the indi- WIIRES vidual muscle fiber or collection of Fig. 2- Various needle elec- fibers (known as a motor unit), which NEEDLE trodes and their cross- sections: are controlled by only one nerve fiber. SHAFT a- monopolar (single wire) SOLID with reference electrode; When a double coaxial needle is used, NEEDLE INSULATING INSULATING b- the shaft of the needle is connected to MATERIAL MATERIAL single -wire coaxial (most corn - a C monly used) ; and c--two -wire ground, since the second wire inside the coaxial. bore acts as the reference electrode. NEEDLE CROSS SECTIONS ARE GREATLY ENLARGED Ground electrodes are used to minimize the effect of stray pickup and inter- ference.

The signals from the needle electrode AUDIO are fed to the input grids of a pre- AMPL amplifier having a very high noise - rejection ratio, flat low-frequency re- sponse and high -frequency -cutoff cir- cuitry. The preamplifier output is fed JUNCTION into a multistage differential amplifier . Box PREAMP with gain enough to produce an increase in signal strength of at least 100,000. This amplifier is designed to produce NEEDLE ELECTRODE T the absolute minimum of waveform TAPE CALIBRATOR distortion. The output stage of this 1 RECORDER amplifier is coupled to the vertical amplifier of an oscilloscope and a tape Fig. 3 -Block diagram of an electromyograph. recorder (for restudy when convenient). Pictures of the waveform may be taken later during the tape playback by arranging a triggering mechanism in I2AU7 6AQ5(2) .05 22K the oscilloscope sweep circuit. This GAIN synchronizes the opening of the camera L UTPUT TRANS shutter with the sweep. Note in the O o block diagram (Fig. 3) that a calibra- tion circuit is also built into the sys- K SIG OUTPUT tem. Also shown is a separate audio O BA. power amplifier (Fig. 4) of standard 500K hi -fi quality which allows the low - 22K .I frequency impulses to be heard through GAIN .05 22K a loudspeaker. This is possible because all the muscle impulses fall within the DPST lower end of the audio PWR TRANS spectrum. S 3A 5 3-GTRECT "IOH 30H The different sounds produced by the various waveforms are very useful to 117 VAC ++ LF COMPENSATION the examiner because each is charac- 5 ?10 T T30 teristic of a particular condition. After some experience with the electromyo- PILOT graph, an individual can recognize an abnormal condition by sound alone. TO HTRS Some muscle impulses produce sounds like static noise in a radio, others like Fig. 4-Audio amplifier used to repro- a diving airplane, still others like duce the sound of muscle contractions. machine -gun fire or a diesel locomotive or the chugging of an old model -T Ford. NOVEMBER, 1960 35

www.americanradiohistory.com Fig. Schematic of corn - 6AU6(6) SIG 5- OUTPUT bination preamplifier, am- plifier and calibrator.

CAL OP

R21 R22

1012 1.9K

8K 1 0 CAL J74I45VII45 VOLTAGE V I45 V ~I45Vr+ Fig. 6- Schematic of oscillo- scope and muscle stimulator. 0 30 DB ATTENUATORS,3DB PER STEP

47K 100K 6AN5 2W 2W CATH FOLL IK /IW STIMULUS OUTPUT JACK

This is not the whole list; there are 250K many others. IW I 15K IOK )F --WW+ IMEG STIMULUS Circuitry R41 ISK The basic circuitry of the electro- STIMULUS DURATION IW IOW AMPLITUDE myograph is shown in Fig. 5. (Since 6AL5 manufacturers tend to object to having LIMITER 6AH6(2) the diagrams of their particular instru- MVB ments published, this is a generalized schematic.) It consists, first, of a high - 5K /IW + 10 250K gain, low- noise, balanced push -pull 150K 200K IW preamplifier with a built -in calibrator. SWEEP GEN There are three stages of push -pull I /z12AU7 R -C coupled voltage amplification. STIMULUS 6BD6 40K 2.2K Because of the tandem balance attenua- DURATION OOK 2W - 5MEG tors R7, 8, 13 and R14, linear amplifi- R20 OFF cation of all input voltages can be 200K obtained. Each attenuator has a loss of 20K 7.5K IW IW 3 db per step. The frequency response Z 25K g R21 IOW is flat ±1.5 db from 10 to 4,000 cycles. 4.05 Extraneous electrical interference is reduced without shielding by the screen - grid balancing R3. Since µSEC /INCH most of such interference appears as 6AN5(2) VERT AMPL a grid -to- ground signal, R3 can be 500K varied to make the unwanted signals I 25K/IOW equal in amplitude. Since they are already 180° out of phase, they cancel SIG 5MEG /2W INPUT each other out. Tubes are shock -mounted 12O0e µr.l .--t(,I I I to prevent vibration. Precision wire - ~ wound resistors in the first stage plus VERT CENT HORIZ CENT careful shielding reduce inherent noise still further. The calibrator circuit consists of a 500K OUTPUT 1.5 -volt battery, R21, 22 and a push- TO SPKR AMPL _.1 OP -CAL is button. When the switch IOOK turned to CAL, depressing the CAL button IW 250K (4) introduces an 0.8 -mv square -wave 250K 750K 250K on 750K pulse. The vertical gain the oscillo- 30Hti IW 30H scope can then be adjusted to the 2W 2W 500K 2W IOOK INTENSITY FOCUS desired deflection height. A well filtered T.5 power supply may be used in place of 301+ T.10 .r.s 20T IOOK the batteries. - 5Y3-GT 6X5-GT The preamplifier output is fed into the vertical amplifier of the scope (Fig. 6). This consists of two 6AN5's which, because of their high transconductance PILOT and high plate current, deliver a high voltage across a low plate -load imped- Y ance. This produces linear deflection (10 ,Q., Jan, because the beam leaves the face of `Oa0` the scope before the tubes are driven S 5A past the linear portion of their char- acteristic curve. The sweep generator 17 V AC 36 RADIO -ELECTRONICS

www.americanradiohistory.com circuit is a negative square -wave pulse for simultaneous display of any other with a frequency of 7.5 cycles. The related physical parameters such as duration of each impulse may be set force, pressure or rotation by means at 1, 0.5 and 0.2 millisecond. The of suitable transducers. The dual -beam amplitude can be varied from 0 to 90 7 -inch cathode -ray tube used has a P7 volts. The stimulator employs a 6N7 screen (a short -persistence blue spot one -shot multivibrator triggered by the followed by a long -persistence yellow - negative pulse just described. The out- green afterglow). put, a negative square wave, is passed The tape recorder will record any through the 6AN5 cathode follower. pattern which can be displayed on the This arrangement minimizes distortion cathode -ray -tube screen. It has a bias - of the square -wave stimulus. Plate and -erase oscillator and a recording current of 6AN5, which is normally amplifier for each channel. The electro- conducting heavily, is reduced by the myographic amplifiers are used for negative square -wave input from the tape playback to obtain good low - 6N7. The current decrease through frequency response and a low noise R41 results in a negative square -wave level. Relays in each amplifier switch output. Stimulus duration is kept con- the amplifier input to the tape playback stant by the 6AL5 duration limiter heads and also insert correction net- which stabilizes the grid- voltage excur- works within the amplifiers to corn - sions of the two sections of the pensate for the nonlinear frequency 6N7. response of the tape. Information The power amplifier (Fig. 4) is a two - stored on tape during electromyography stage resistance- capacitance - c ou pled may be played back through the '.oud- circuit, with frequency compensation in speaker and the cathode -ray display the plate circuit of the first stage. The system for study or photorecording as output is flat from 10 to 10,000 cycles, well. The tape -recorder mechanism uses but the lows may be accentuated and three motors and electrodynamic ten- the highs attenuated by switching in sioning in its design, eliminating slip the low- frequency booster. The output clutches and mechanical complexities is 6 watts undistorted. Careful atten- (and a need for critical adjustment). tion to power -supply design is respon- The technique of electromyography sible for the very low hum level. is still in its infancy and there will no doubt be many changes in instrumenta- Commercial equipment tion in the near future (since most of It is worth mentioning at this point the larger institutions are now begin- TECA Corp. two- channel electromyo- that a number of commercial pieces of ning to use this important diagnostic graph model TE -2 -7. equipment are available for electro- tool). Extremely important information myography. One of these is seen in is being obtained with this technique employs an 884 , a 6BD6 the photo. This is a two -channel unit in the research on such diseases as constant -current and half of a with a twin -gun scope and a two - polio, muscular dystrophy, myasthenia 12AU7 limiter. Normally the 884 channel tape recorder (using both gravis and many others. It is hoped thyratron is biased to cutoff and is halves of a standard 14-inch tape). that some of the answers being sought prevented from flashing or conducting This machine also incorporates a lie in electrical abnormalities in muscle by the 12AU7 limiter connected in muscle -stimulator circuit for use during and nerve tissue. This is what makes parallel with it. However, a positive the examination. The two channels give medical electronics so important (be- pulse from the multivibrator raises the the advantage of being able to compare yond pure instrumentation). Other grid bias of the thyratron, causing it one side of the patient with the other. phases of its application will be dis- to conduct and thereby charging C4. The second channel may also be used cussed in future articles. END This capacitor is then discharged at a linear rate through the 6BD6 constant - current pentode. When the potential across C4 drops to a low value, the grid of the 12AU7 limiter is driven positive with respect to the cathode (since the cathode is made more nega- in tive than the bias on the grid by R20 Nobody gets fooled and 21). As a result, the 12AU7 con- ducts heavily, preventing further con- duction by the thyratron until the next RADIO-ELECTRONICS! positive trigger pulse arrives from the multivibrator. The multivibrator itself consists of two GAHG in which the screen grids are used as plates for the switch- Fast operating tube salesmen are ing action. The circuit provides positive not permitted to try their shell game pulses for triggering the sweep gen- in the advertising pages of Radio - erator and negative pulses to trigger Electronics. Since January 1956 we the muscle- and -nerve stimulator circuit. have insisted that mail order tube The frequency is set at 7.5 cycles. The advertisers tell you directly if square -wave pulse from the appropriate the tubes they were were plate of the multivibrator is passed selling through a differentiating network to either new and unused, or imperfect produce the sharp, positive trigger if that was the case. It's cost us pulse for the sweep generator. The money in advertising but saved our negative trigger pulse is obtained from readers more than just embarrass- the grid of the nonconducting tube of ment. the multivibrator as it suddenly swings negative. The output of the stimulator

NOVEMBER, 1960 37

www.americanradiohistory.com FINALLY AKES i T Radio's "dead dog" now begins to look like the wave of the future

By DAVID LACHENBRUCH

JUST 4 years ago, FM radio was offi- room, the car. Music was just a thrum- San Francisco and its suburbs have 19 cially "dead" as a broadcasting me- ming noise to beat eggs to or to keep FM stations to 21 AM outlets. dium. Its phenomenal rise immedi- you awake on those new turnpikes. And people are listening! No reliable ately after World War II was By 1954, FM radio production had set count has been made, but it's esti- nipped in the bud in the late 1940's by dropped to an annual rate of less than mated that at least 10,000,000 FM sets the coming of television. Now there was 200,1)00 sets. There were still about 550 are now in regular use. That's one out nothing left to do but call in the under- FM stations on the air to Provide some of every four households in the country, taker and fight over the will. It seemed programming for the listeners who were even though many rural and small -town that the only legacy FM would leave stuck with FM sets, but the vast ma- areas aren't yet adequately served by was the valuable spectrum space be- jority merely broadcast the programs FM stations. tween 88 and 108 mc, and the heirs carried on their sister AM stations (at Why the big boom now? The common (various nonbroadcast services) were just about the sanie fidelity). and most obvious answer is that people already fighting over it. From this low point, let's look at have become more conscious of good But the corpse refused to lie down what is happening in 1960. By mid -year, music and high -fidelity sound reproduc- for the funeral oration. Artificial respi- there were already 741 FM broadcast tion. But there's more to it than that. ration by about 500 FM broadcasters, stations on the air -ahead of the record There couldn't be an FM boom if a handful of radio manufacturers, sev- 730 in late 1959. There would be more, there were no stations. The 500 -odd eral thousand hi -fi enthusiasts and the except that there weren't enough chan- (and some of them were quite odd) FM Federal Communications Commission nels to go around -and applicants were stations which hung on during the lean kept it breathing. competing with each other to prove their years did it mainly from force of habit. If FM died in 1950 -as many people qualifications to operate FM stations It didn't cost much to keep the FM believed at the time-today it's a very in such cities as Los Angeles, New York, transmitter operating, repeating AM lively zombie. And now, for the first Chicago, Philadelphia and Washington. programs. And there was still a hard time since 1948, its future seems virtu- This year, too, will see FM receiver core of rabid hi -fi FM fans, who would ally unlimited. production and sales exceed 1948's rec- raise a ruckus if the stations went off To get an idea of the kind of come- ord by perhaps as much as 30';. Our the air. back FM radio has made, look at the estimate is that factory production of Some broadcasters did deliberately charts showing FM stations on the air sets designed for sale in the US will knock their FM outlets off the air and factory sales of FM receiving de- total close to 2,000,000 units this year, for a week or so just to see if there vices (Figs. 1 and 2). In both leagues, possibly even more. would be adverse reaction. There was. you will see that FM is setting an all - At the mid-point of 1960, the FCC So they knew somebody was listening. time record in 1960. had authorized another 169 applicants But there was still no way to make Immediately after World War II, FM to broadcast on the FM hand -in money out of FM broadcasting. A few was hailed as "radio's second chance" addition to the 741 already on the air. stations tried simplex operation (broad- and the first FM boom was on. By 1946, Of the stations on the air, a large pro- casting to restaurants and businesses) the FCC had authorized more than 1,000 portion were broadcasting special pro- with special equipment to eliminate FM stations -many of them to recently grams on FM only -even those sta- commercials in these establishments. discharged veterans who wanted to get tions who also owned AM outlets. Simplexing was outlawed when FCC a foothold in this new and superior type And there seemed to be no end to the established multiplexing rules. Today, of radio broadcasting. applications flowing into the FCC for 208 FM stations are authorized by the In 1948, when nearly 700 FM stations new FM stations. An FM expert at the FCC to multiplex (transmit a special were on the air, radio factories sold commission estimates that by the end program in addition to the normal one, 1,600,000 FM radios and tuners. But of 1961 there will be more applications and unheard by the regular listeners) things were far from rosy. than there are available FM channels for various purposes, most of them for A new type of broadcasting suddenly in most cities with a million or more special storecasting and functional mu- was creating public excitement- broad- population. sic services. This is providing needed casting you could see! Television was The Los Angeles area already has revenue for stations with the courage to here, and as picture tubes got larger, 28 FM stations compared with 21 on program their FM outlets separately speakers got smaller. Radio became AM. In New York City and environs from AM -for very few FM stations an appliance for the kitchen, the bed- there are 23 FM stations and 24 AM; are yet showing a profit on broadcast

38 RADIO-ELECTRONICS

www.americanradiohistory.com Fig. 1- Estimated factory sales of re- ceiving devices (including foreign units sold in U.S.). Included are TV sets with continuous tuners that receive the FM IMPORTS (100,000) band, of which 420,000 were produced in 1949 alone. COMPONENT FM TUNERS (150,000) operations. Madison Avenue ad agen- cies, by and large, still don't realize how many people are listening. Hobbyists and sound enthusiasts nev- er abandoned FM. In areas where sta- tions were broadcasting good hi -fi mu- sic, was a small but loyal audi- there FM & FM -AM TABLE RADIOS (800,000) ence of hi -fi bugs with component rigs. 4 But the radio makers who went into television production forgot all about FM -with one exception. Zenith kept turning out FM table radios and, be- cause it was virtually the sole manufac- turer, did a fairly brisk business in them. When the LP phonograph record be- gan to arouse real consumer interest with its excellent reproduction, FM's second boom began to germinate. Among the first high -quality phono- graphs introduced in this country for realizing the full sound potential of LP PHONOGRAPHS WITH FM (900.000) records were German -made units. In Europe, where the post -war AM band was hopelessly overcrowded, FM broadcasting has become standard - strictly from necessity. German phono- graphs with radios included naturally contained FM tuners. The American purchasers litstened, and pricked up their ears. Then came the "cheap" FM set, pio- neered by Granco products, who sold scads of FM -only table models at $29.95. Other manufacturers followed. When American radio manufacturers began to offer hi -fi consoles in a single package, they took another look at FM -largely because the German units had them. A few dropped in FM tuners as extras or even as standard equipment on some models. Cr._ , Û, Then along came stereo. Experimen- `Y' -=a- ,_r, s .r , - > r tal AM FM stereo broadcasts aroused c-, c> = . c C.7> G"."3 ) , c) the interest of set manufacturers. To- day, most makers of so- called "pack- aged" hi -fi offer "drop -in" simulcast AM FM tuners as an option. Some manufacturers estimate that more than 70 % of their stereo consoles now are 1000 sold with AMFM tuners. Industry- TOTAL FM STATIONS AU-HORIZED wide, it's a good guess that the propor- 900 tion is more than 50 %. In the field of hi -fi components, manu- 800 facturers say sales of FM tuners are increasing, too. The concept of the com- 700 bination tuner, preamp and amplifier has resulted in added FM sales. 600 Our estimate of close to 2,000,000 new á FM receivers this year includes all types wr of devices to receive FM broadcasts. It r..5 300 breaks down this way: Table -model FM and FM AM radios, 750,000 to 820,000 100 units (up from 540,500 made in 1959) ; "packaged" phonograph systems with 300 FM tuners, 700,000 to 1,000,000 (from FM STATIONS ON AIR 623,000 last year) ; component FM tun- ?00 ers, 150,000 to 200,000 (from an esti- 100 Fig. 2 -FM stations actually on the air, by years. Low -water mark came in 1956 after many stations had given up and gone off the air. Some of those silent stations have now been reactivated. NOVEMBER, 1960 39

www.americanradiohistory.com set. You mated 150,000) ; imported FM receiving ers with a battery-operated devices of all kinds, 80,000 to 120,000 can expect many more models -from (from about 100,000). Japan, Europe and the US -next We have given a high and low figure spring. FM clock radios, too, will be in each case, because estimates within coming into their own soon. Other FM the industry vary widely. Adding up receiving devices are on the way also, the "lows" would give a 1960 minimum including the return of the combination of 1,680,000 sets (compared with 1,413,- TV and FM set (Magnavox introduced 500 last year) ; the "highs" total 2,140,- a new one this year). 000. The best guess is that the final But FM's biggest push will come from 1960 figure will be closer to the high the source that gave hi -fi its largest estimate than the low one. lift -stereo. What of the future? Write this down Nobody knows when the FCC will and paste it inside your hatband: You're finally establish standards for FM ster- going to see more and more FM sets eo multiplexing. Engineering work and in the coming years, and FM radios field testing of all proposed FM stereo will some day rival AM in popularity. systems have been completed by the Here are some of the reasons FM radio National Stereophonic Radio Commit- can't go any place from here but up: tee, an industry -wide group established FM achieved its sales record this by the Electronic Industries Association. year despite the fact that it isn't yet a The opening gun for FM stereo nation -wide medium. Many areas have broadcasting could come very soon. Or few FM stations -or none at all. This it could be delayed for months by legal situation is rapidly changing, and FM action and bureaucratic red -tape. But broadcasting will be transformed in it's coming-and every radio manufac- the next few years from a basically turer is poised to be off and running By ROBERT M. VOSS big -city service to a type of radio which with the "first FM stereo radio." The FCC, too, is eager to get FM reaches into every nook and cranny of HE 6DZT, recently put on the mar- America. stereocasting started almost immedi- ately. But delays could result if its de- ket, should solve a few space and New types of FM receiving devices circuit problems of audio -amplifier are just beginning to come on the mar- cision on a specific multiplexing system 1 designers. It consists of two beam - is challenged either through the FCC's ket. The one with the biggest immediate power pentodes in an envelope the size potential is the FM auto radio. German own rule- making machinery or the fed- eral courts. Because so much depends on of a 6L6 -GB. The sections have a com- manufacturers (including Blaupunkt mon cathode and internally connected and Becker) have been offering FM car the FCC's decision, this is a distinct possibility. screen grids. With 400 volts on the radios here for several years. Smaller plates and 250 on the screens, the tube US manufacturers (Gonset, Automatic, The establishment of FM stereo multi- plex standards by the FCC will mean wll deliver 20 clean watts into a 14,000 - and others) have also had FM tuners - ohm load. - almost immediately-that FM tuners and converters for cars. But the big the internally tied screens is just will be a must in all new stereo phono- Naturally, business FM car radio push limits the possible uses of the tube. It beginning. graphs; stereo tuners will be added to existing ones; a whole new field of obviously cannot be used for Ultra - It actually started with Motorola's Linear or unless two an FM -only stereo FM table radios will open up; triode operation, introduction this year of more used in a push -pull -parallel which reportedly has all hi -fi rigs must be equipped with or are car radio at $125, circuit. When powered by a supply that well by the customers multiplex converters. been accepted delivers 250 volts at 90 ma, the 6DZ7 despite its relatively high price. Every radio manufacturer now has engineers designing multiplex receiver will put out 10 watts into a 9,000 -ohm The race was really on with the debut load. by Emer- circuits -even before the FCC itself Granco converter (marketed Besides using the 6DZ7, the amplifier son Radio) at $49.95. Granco, which knows which system will be adopted. Radio makers expect the FM stereo described here has one other unusual specializes in low- priced FM sets, hopes though not unique feature uses sili- will do for the auto mar- decision to touch off the biggest con- -it its converter con diodes in the power supply. Having FM table model did sumer- electronics boom since TV, and ket what its $29.95 had no experience with silicon recti- home market. Its president, to vastly increase stereo phonograph for the fiers, I tried to use only two Sarkes sees a market sales as well. Henry Fogel, "reliable Tarzian K -200's in a standard full -wave FM a year" begin- Will FM ever realize its proponents' for 100,000 auto sets hookup. Both shorted after about 15 in 1961. long -time dream of replacing AM? We ning seconds. The moral voltage rat - in the don't think so. But it is being increas- -the You'll see other FM car radios of rectifiers must be derated Roebuck even has ingly accepted for what it really is -a ings silicon coming months. Sears, considerably when feeding a capacitive one now in its fall catalog. far superior form of radio. It's building load (see page 40, June, 1960, RADIO - The portable FM transistor radio is up real momentum now, and with the introduction of stereo multiplexing ELECTRONICS) . (Even with the 150 -ohm just in its infancy, too. Zenith is now capaci- manufactur- there'll be no stopping it. END resistor the load is essentially competing with Japanese tive.) Therefore, it is necessary to use four in series -two in each leg of Ti's high -voltage winding. Inspection of the rest of the circuit will reveal nothing unusual. A pentode voltage amplifier is direct -coupled to a phase splitter. The ba ance control is adjusted for equal ac voltages at the output tube plates. Feedback is, in the conventional manner, returned from the output secondary to the input cathode. The heaters are biased at 10 volts to reduce hum. A stereo amplifier may easily be built using the same amplifier circuit. It is "That wouldn't do. necessary to change only the power Most of my listening transformer and choke; the rectifiers is done after sunset." will easily handle the added current. -ELECTRONICS 40 RADIO

www.americanradiohistory.com AMPLIFIER Neat little R17 R9 P.12 RIO C? C4 10 -watt amplifier has a 1 -tube push -pull output stage ... uses a new dual -pentode

C2 R5 RS R3 RT"- R2

6AN8 A look er ri l'utentjonorter I16 tnounted on 1.1-ahap=d bracket. VOLTAGE AMPL PHASE SPLITTER

R6 - BALANCE 20K 6DZ7 PWR AMPL 10 watts R3 220K 39K 1. IW R11 Sensitivity: 350 my input for full output CI-a R5 I W R7 C3 27K OUTPUT TRANS 40 1E 20- 20,000 cycles within I db 450V :05 3 T2 distortion below 1.5% VI-a 6 I VI-b R9 160 RII41C5 25 50V I7 -db I kc 270K 5)15_0V 15K 1120µf feedback at J R2 7 80 1 hum and noise 55 db below 10 watts

IOK RIO Unit was tested for frequency response, power .1 270 output, distortion, hum and noise, RI C2 9 3 C4 . 1250 00 470K K IOW and sensitivity. All results verified R8 R4 .05 R12 WW the author's statements and are 3300 47K 27K IW summarized above. Conclusions drawn from the tests are: "The BENCH RECTS I-4 Voss amplifier will give satisfac- 260V /200MA EACH 8H tory service as a ij -f amplifier in TRANS Circuit of the ampli. PWR 150MA low- or medium -cost systems." TI 142 fier. Note there are ,I R16 CH F 520 V CT only two tubes. ro vn 90MA R/1450(3Z) +1 1.50 1500 1+ 117 VAC 5W CdI-c CI- TESTED WW }T10 40 °I3 4 / \450V 6.3V/4A R17 4700?

R2- I0,000 ohms V2 VI R18 R3- 220,000 ohms R4-330 ohms R5-I megohm R6 -pot, 20,000 ohms, linear R7- 39,000 ohms, I watt R8- 47,000 ohms, I watt R9 10- 270,000 ohms RI I, 12- 27,000 ohms R13 -125 ohms, 10 watts, wirewound R14- 15,000 ohms R15-4,700 ohms R16 -150 ohms, 5 watts, wirewound R17, 18-470 ohms All resistors 1/2-watt 10% unless noted CI-40- 40 -25 -10 Af, 450- 450-50-450 volts, can type electrolytic (òornell- Dubilier DO -65 or equivalent) C2-0.I µf, 600 volts, molded tubular C3, 4-.05 µf, 600 volts, molded tubular C5-120 µµf, disc ceramic CH- choke, 8 henries, 150 ma, 145 ohms (Thordarson 20054 or equivalent) F-1.5 amps J -phono jack RECTI, 2, 3, 4 -360 volts, 200 ma (Sarkes- Tarzian K -200 or equivalent) TI -power transformer: primary, 117 volts; secondary, 520 volts ct, 90 ma; 6.3 volts, 4 amps (Stancor PC -8420 or equivalent) T2- output transformer: primary, 9,000 ohms plate -to- plate; secondary, 8 and 16 ohms (Stancor A -8054 or equivalent) VI -6AN8 V2 -ADZ7 (G -E or equivalent) Chassis to suif Miscellaneous hardware END This is how tlie completed am?I,lifier looks.

NOVEMBER, 1960 4'1

www.americanradiohistory.com By I. QUEEN EDITORIAL ASSOCIATE newest thing in radio is the tunnel THEdiode. This amazing diode has built -in negative resistance and operates on a few hundred n3v of bias. It can oscillate, amplify and switch. A novel application for the is shown in the schematic. This is an oscillator tuned to about 11 meters by L and C. The diode is a Texas In- struments unit 1N653, now available on the market. It is energized by a Hoff- man S -lA solar cell, placed 4 to 5 inches from a 40 -watt lamp powered by the 60- cycle line. The 1N653 has three leads, one for the cathode and the other two for its . The rf is modulated by a 120 -cycle buzz, from the ac output from the cell when illuminated by an ac lamp. The ac generates many strong sidebands above and below the carrier, resulting in a very broad signal. Measurement shows nearly constant output over a Generator and solar cell power supply. mc or more! For example, with typical coupling to a receiver, an S7 signal was noted throughout the band, and prac- tically zero outside. There is a slight variation in fre- quency with the amount of light falling on the solar cell. Here are some results 1 TUNNEL DIODE obtained: Bandwidth (mc) Cell output (mv) 25.5 -27 180 27.0 -28.2 200 29.0 -29.8 240 NOISE The voltage was measured directly across the solar cell. Varying the dis- tance between lamp and cell changed the mv output. Over the bandwidth GENERATOR. noted, a loud hum was heard in a near- by receiver. The output from this simple genera- tor is low; there is little danger of cre- ating interference. A superregenerator will receive the hum signal up to about Three components and a power source 10 feet from the oscillator. This signal can serve to check the performance of a make a useful test instrument receiver or for alignment and adjust-

D -IN653 Socket for above C -.001 µf, disc L -16 turns No. 18 enameled, I/4 -inch diameter close - wound SC- Hoffman S -IA photocell

1N653 SC IN653 ATH S-IA

16T, N°18 WIRE, I/4°DIA Noise generator is inherently simple.

ment. For example, if the oscillator is adjusted for the Citizens band, you will have a strong signal inside the band, practically nothing outside. The oscillator requires a low- resist- ance power source such as the solar cell mentioned above. Other types may not be suitable for this purpose. Note that the diode must be biased in the conduction direction. This circuit is a good start if you want to experiment with the tunnel di- ode. The solar cell output is so low that Nothing bulky about this instrument! it cannot damage the diode. END 42 RADIO -ELECTRONICS

www.americanradiohistory.com HOWTO FIX R ADIOS TASTER («ad make mole money)

By JACK DARR THE two figures, one tall lanky and Ham. "But only five minutes!" "There she is," he cried. "How much balding, the other shorter and "All right, I'll have to show you," time did that take, now ?" crew -cut, came out the back door said the Old -Timer wearily, settling "Four minutes, 45 seconds," said the of the drugstore and went down himself creakily on the stool at the Young Ham. "But, hey! That ain't fair! the alley. From the amount of arm radio end of the bench. "Gimme one of There wasn't anything wrong with it! waving and jaw flapping, it was ap- them sets." Just had a dead tube!" parent some kind of discussion was The Young Ham handed him a small going on! As they drew nearer, the Old - radio from the unfinished work bench. Just a dead tube? Timer could be heard to insist, "Five "You watch th' time. Holler when th' "Whoa -up!" demurred the Old- Timer. minutes, I said!" hand gits to 60." "For your information, young feller, "FIVE MINUTES!!" howled the The Young Ham watched the shop this set had a dead tube, a noisy volume Young Ham. "Why you can't even get clock, then called, "Go!" control, a noisy tuning capacitor, the a radio warmed up in that time!" The Old -Timer plugged the set into dial was off calibration and t cleaned They came in the back door of the the bench wattmeter, watching the it up too. Now she's back in good shape shop and down the long hall. "Five min- needle -it didn't move. Removing the again, and I'm gonna charge the cus- utes," repeated the Old -Timer firmly. back, he pulled the tubes and plugged tomer a bit extra for takin' care of ad "If you can't get a firm diagnosis on them one at a time into a small bat- those little things. Result: she gits a any radio in 5 minutes, you sure need tery- powered continuity tester. One better -playin' radio so she's happy, we your procedures re- examined! Theo- failed to light the indicator lamp. make more money so I'm happy! How- retically this is a money -makin' busi- Hopping up, he grabbed a tube from the ever, that ain't th' point I was tryin' ness, right? Right. Well, now, radios shelf and inserted it in the socket. The to make. That was easy, yeah. But, if are an important part of it! Look there. wattmeter needle now showed about 30 you'll check back in your memory, you'll A flock, seven or eight of 'em, came in watts and the set began to hum softly, remember that near 90% of th' radios this morning! All right, if we can fix then play. Turning the volume control we service ain't got anything but a 'em fast enough, we can make money. wide open, the Old -Timer ran up and dead tube wrong with 'em, plus little If it takes us all day, we lose money. down the dial, listening to the different stuff like this. So, if you can git th' Why? 'Cause radios don't cost too much stations. He turned the volume control easy ones playin' quick, you'Il have a nowadays. They're either new low - several times, then took the chassis out little more time to spend on th.' harder priced sets or older ones that have de- of the cabinet. Turning it upside down, ones." preciated. We jist can't git a $19.95 he squirted fluid from a spray can into "Th' darn trouble is, most of 'em are service charge on a $12.95 radio and the control. Flipping it over again, he either real easy or real hard!" com- that's all there is to it! sprayed the tuning capacitor. Then, plained the Young Ham. "Your diagnosis is th' most important tuning in a station near the high end "They ain't any of 'em real hard if part. Fixin' th' set'll take maybe 20 of the dial, he adjusted the trimmers you use th' proper procedure on 'em," minutes or so. That's O.K. We can let on the gang for maximum volume. returned the Old- Timer. "You might 'em off for a couple or three dollars Picking up a rag, he wiped the inside not have noticed, but I used quite a few service charge. But, if you spend 2 or 3 of the dial glass, and the dial scale shortcuts there while I was checkin' hours tryin' to find out what's wrong itself. Slipping it back into the cabinet, that set. F'rinstance, by the way it with it and another hour fixin' it, we're and replacing the screws and knobs, he played and the volume I had, ard th' in th' hole!" ran the dial over its full scale. Turning number of stations it got, I knew that "Yes, but -," yes- butted the Young it off, he whirled around on the stool. the power supply and th' rest of th'

NOVEMBER, 1960 43

www.americanradiohistory.com SET PLUGGED IN

TUBES LIGHT Fig. 1 -The Old TUBES DO NOT LIGHT f Timer's family tree of radio troubles.

CHECK CHECK PLAYS TUBES LINE CORD, WEAKLY SWITCH, WIRING WEAK OUT OF POWER SUPPLY- TUBES ALIGNMENT WEAK RECTIFIER, OPEN INPUT FILTER CAPACITOR,ETC PLAYS FAIRLY GOOD, BUT

OSCILLATES NOISY

l' IF TUBES FILTER SHIELDS AVC CLEAN CLEAN LOOSE CONTACTS BAD CAPACITOR MISSING BYPASS VOLUME TUNING OR BAD SOLDER (GASSY) WEAK OR OPEN CAPACITOR CONTROL CAPACITOR JOINTS OPEN

} I

Fig. 2- Signal path through any vacuum- tube radio.

tubes were OK. Why? Because it learn it by heart. Hmm, poetry already! this into your head when you first played as good as the average set of No kiddin', if you've got that up here," started out? It can be thought of as a that size oughta -got as many stations, rubbing the Young Ham's burr head, series circuit -th' signal starts at the played as loud, an' so on. If it'd been "it'll always help you out! Say, didn't antenna and keeps on goin' on a single weak, I'd have checked voltages and I give you something like this quite a path until it gits to the speaker! Any- tubes while I had it out of th' cabinet. while ago, in a different form? What thing that causes a break in the path See?" happened to that notebook you used to stops th' signal! To find it, all you "Yes, I do," said the Young Ham. keep that stuff in ?" gotta do is feed th' right kind of signal "But it sure takes a lot of experience to "It's here somewhere," answered the into each stage and see where it stops!" recognize all of those things!" Young Ham, scrabbling in the litter at "Yeah, but it ain't always as easy as "Son, experience is what you're get - the back of the bench. "Here it is," and that," demurred the Young Ham. tin', right here." The Old -Timer he pulled out a medium -sized notebook, "Yes, 'tis," argued the Old- Timer, "If grinned. blowing the dust off it. you know what a normal response is, "That's for sure, Pappy," laughed the "That's about what I thought," you can always find a stage that ain't "Young Ham. I sure ain't gettin' rich got it, if you know what I mean." on the laughed the Old- Timer. "There's quite salary you pay me! Why didn't "Well, it's a little mixed up, but I I get an accumulation of dust on that ma- a paper route like the other kids ?" terial, meanin' think I'm beginnin' to get it." "'Cause you couldn't git up it ain't been used for that early some time, huh ?" in th' mornin'," said the Old- Timer, "Well, I hope so," said the Old- Timer. with a straight face. "Now, looky here. "Awww," said the Young Ham, "I "Now here is the more detailed check Lemme show you once more, an' see if ain't needed it much till now." list that I worked out for you a while 45). You follow this all the you can't remember it, this time. Here's "Junior," said the Old -Timer seri- ago (page what you might call a `Family Tree' of ously, "you always need pref- way through, an' I'll guarantee you'll that stuff, quick- like!" radio troubles." He sketched rapidly on erably up here between th' ears, but if find your troubles right a piece of paper (Fig. 1). "Now, not then somewhere where you can git "Well, sir, I jist bet you're right," if you'll follow this outline for quick - at it. Gimme." He took the notebook, said the Young Ham, in an exaggerated checking every set, you'll be surprised and leafed through it. "Yeah, here it is. imitation of the Old- Timer's drawl. "I'll how much you can cut down your Now, here's something you want to re- bet you what I know you'll like better." diagnosing time!" member. This signal -path schematic "What ?" said the Old- Timer, in mock The Young Ham studied the drawing. here (Fig. 2) . This is nothin' but the innocence. "Yeah," he admitted, "I can see how it parts of th' set that actually handle "A cuppa cawfee!" said the Young would." the signal! It'll fit all radios, I don't Ham, making a dash for the door. "It will, it will," affirmed the Old - give a dery what kind they are! Don't "Right!" agreed the Old- Timer, follow- Timer. "Just remember that chart, an' you remember how I used to hammer ing him out. END 44 RADIO -ELECTRONICS

www.americanradiohistory.com THE OLD TIMER'S CHECK LIST 4444444444444 I. Tubes, check. For continuity. Don't Miss 2. Voltages, check. Since the majority of radios now are ac -dc, the volt- ages are given for them. Others can be checked from service data. these a. Audio output 90-100 v b. Audio output screen 90-100 v c. 1st audio platet 40-50 v* Highlights d. if amplifier plate 90-95 v e. if amplifier screen 90-95 v f. mixer -oscillator plate 90-95 v g. mixer -oscillator screen 90-95 v h. avc voltage. Measured at diode plate, and on if or mixer grid. On strong NEXT local station, should be 8 -10 volts, negative.t i. Oscillator grid. Measured on oscillator grid. Should read 10 -12 volts negative, varying as dial is tuned from high to low end. Highest voltage at high- frequency end of dial.t * Watch this one: If its too much, the tube may be very weak! Should never be over about 50 volts. Too -high voltage indicates tube not draw- MONIlI ing enough plate current. tMeasured with vtvm. Three Ignition -Operated 3. Signal path. As voltage measurements are made, listen for 'pop' when probe touches plates and grids. Pop should get louder as you go toward the _ Tachometers antenna. No sports car fan would b. with- out a tachometer. Theà'r very useful too for checking engine speed on cars, outboarc motors, 4. Use signal generator. Put on audio output racing models or other engine Signal injection. audio signal driven equipment. Here are three grid, then 1st audio grid. If signal on if amplifier grid, then on mixer grid. dependable transistor - operated units are lb.rild. Rf signal on mixer grid, then on antenna. Signal should get louder as you go that easy to toward the antenna. (Shortcut: touch center connection (slider) of volume control with finger or screwdriver -volume full up. A good loud buzz should result. This means Electronic Timer audio stages and power supply OK. No buzz, trouble in audio stages.) Integrates Light A unique all- transistor device that is controlled by the amount of 5. Alignment. Feed signal at specified if into if grid, tune last transformer. light it receives instead of remain- Move signal generator to mixer grid, tune first transformer. Tune signal gen- ing "on" a given number of sec- onds. Invaluable for electronic erator and set dial to about 1400 kc. Feed signal into antenna by laying output photoflash operation and other ap- cable on bench nearby or clipping it to edge of loop. Tune antenna plications where ordinary timers for maximum. just won't do.

Output indicators: What you need is something to read the amount of signal Ultra- Sensitive coming out of the set. Connect ac voltmeter across voice coil to read demodu- 3- Transistor lated signal. A vtvm can be connected anywhere in the if network, except the grids themselves, and the avc voltage used for alignment indication. Avc voltage Regenerative Radio will increase (go more negative) as set is tuned up. Always keep signal generator For those who want more sensitiv- ity than usually found is ? -tran- output low, to prevent blocking. Should use meter reading of I to 2 volts. sistor radios (and good selectivity too). A special input circuit con- trolled regeneration, larger than - Audio Hum: leaky or open filter capacitors. Symptom: hum will usual antenna loop and c ireful distortion: choice of components do the crick. not be reduced as volume control is turned down. Heater -cathode leakage in An ideal project for the I-.obbyist. audio output tube. Open loop antenna; this hum will decrease as volume control turned down. Electronic Strain Distorted tone: Speaker -cone dragging. (Turn set off, move cone with fingers Gauge and its Uses very carefully, listening for rubbing.) Leaky coupling capacitor on grid of power This versatile instrument is used amplifier tube. Measure grid voltage. Should be zero, to check the design of all kinds or slightly negative. If of equipment and structures from 2 to 3 volts positive, replace capacitor. Also check output tube for grid emission. airplanes to bridges. It plays a vital role in engineering progress in many fields. This illuminating Hum while station tuned in: Leaky or gassy mixer -oscillator or if amplifier article tells how strain gauges are made and how they're used in tube. Check by substitution. industry.

Oscillation: Weak or open filter capacitors. Open avc bypass capacitor. Open screen bypass capacitor. eeeeeeoeeeete NOVEMBER, 1960 45

www.americanradiohistory.com COVER STORY

build the The counter tells you how RALLY- PAL far you should have gone at any given instant COMPUTER

By JACK ALLISON

IF you are one of those unrepressed as regular features of their programs. The rallyist turns our equation souls who still think driving is fun, The complexities of rallying make a around. He knows that if his clock then rallying is the sport for you. navigator a must. He (or she) does the shows 30 minutes have elapsed and his In spite of what some people think, mathematical gymnastics necessary to odometer (mileage indicator) turns up rallying is not racing. Far from it. A see that the car is properly located on just 15 miles he has done this "leg" rally, or "rallye" as some purists would the route (and everything else the of his route at a precise 30 mph. Rally- have it, is an individual competition in driver can't do while driving). This ing can be done several ways. Some which drivers try to find their way over often means husband and wife teams. competitors use a book of rally tables an unfamiliar route. At the same time This point alone makes rallying popular. to help them figure out their time - they attempt to maintain a prescribed Navigating is done on one simple distance ratio. These are usually ac- speed (always less than the posted premise. At an even speed you can cover curate to the nearest minute. You speed limit). Check points are set up a certain distance in a precise time. For can successfully compete in a rally with along the route at locations unknown to example, if you travel 30 minutes at 30 nothing more than a stop watch and the driver. When he comes to one, he mph (most rally speeds are to the one of these books, provided not too pulls in and his time of arrival is re- nearest tenth of a mile per hour), you many other cars are fitted with more corded. This makes "being at the right will cover exactly 15 miles. However, elaborate gear. More advanced rallyists place at the right time" a continuous little annoyances such as other cars, use a stop watch for reference only. challenge. Hundreds of motor- sports stop lights and turns make it impos- They prefer to have a short -wave re- clubs all over the country run rallies sible to keep the even speed called for. ceiver in the car picking up WWV or 46 RADIO -ELECTRONICS

www.americanradiohistory.com The components are not critical, but this information is worth noting: The heart of the unit is the potentiometer. It should have a resistance of &D,000 ohms over a 180° shaft rotation. Stand- ard units go 270 °, so check the unit you select with an ohmmeter. I used an Ohmite AB 250,000 -ohm clockwise -taper (type CA 2541) unit and found i gave the required 60,000 ohms over the first 180 °. A linear pot might be easier to calibrate. Use a good unit and see that it is securely mounted. Any mol.ernent of the pot after installation will ruin your calibration. The counters are available from Allied Radio (100 N. Western Ave., Chicago, Ill.) or Power Instrurnemt Co. (254 Canal St., New York 13, N.Y.). The type shown on my model and a somewhat neater looking flush- mount- ing model (MD6- 54 -115A) both sell for about $14 and change. The OB2 regulators may, if desired, be replaced with a Motorola 1031200Z silicon . Simply us one diode in place of the two OB2's. The dropping resistor (R6) remains the same, 4,000 ohms. The relay may be almost any 5,000 - ohm unit. A check of the local surplus ON -OFF PILOT S3 S2 TIMER outlet may save you quite a few dollars. R5 is up of power made a 270,000- and a On -off switch on computer controls supply. S2 is used to advance the counter 180,000 -ohm in to any desired reading (to match odometer). resistor series. Calibration CHU, the American and Canadian time proach. If you calibrate the unit care- Calibration is the next step. Here, standards. Since nearly all rally officials fully, it can do the job as well as or accuracy is essential. You are setting use these stations to time the rally, if better than the high -priced instruments, the unit's timing and this cannot be you have this signal beeping away in because it incorporates its own time changed without an entire recalihration. your car, at least your time factor can- factor. Do it right the first time. not be in error. Stability is easy to check. 113n the The computations for time and speed Construction unit at slow speed for 10 minutes, note to give you distance are often clone with You may follow the photo or you may the counter reading. Do it again,. the little grenade -size cumulative adding want to try out another layout (such as reading should not vary more than one machines. The machine is fed the dis- mounting the counter only near the digit. A check at a higher speed t also tance you should cover in 1 minute at driver). This is up to the individual. The advisable. any given speed. The navigator then basic, simple, circuit (Fig. 1) can be Set the RANGE switch on 5, the dial faithfully cranks the little handle every adapted to any housing with little at zero (or 100, whichever is faster) and minute and you find out the total dis- trouble. The most important factor is the counter at 9,999 (it will flip to tance you should have traveled at the reliability. Use strong connections and 0,000 as soon as the counter is started). end of that minute. You then speed up mount the parts so they can't give Start the computer and the timer (stop or slow down until you zero in and trouble. A Heathkit power supply watch) simultaneously. After a 10- everything is fine. (model VP -1 -12) was used. minute interval, stop the watch and com- Other devices that do the same job puter at the same time. are available. They are all rather costly. Make a record of the counter read- The little Curta, from Lichtenstein, of ing, dial setting, switch setting, time all places, costs $125 to $160, depending elapsed and number of counts per min- on the model. Kearfott has the fanciest ute. The time elapsed should be exact - outfit I've seen and it costs $250! With R7 COUNTER RI- 62,000 ohms, 5 %, I watt R2- 120,000 ohms, 10 I it, you just turn a little handle until 1.5 K COUNTING RATE %, watt 93- 150,000 ohms, 5 %, I watt 5% RANGE a R8 R5 240,000 5 I the speed you want reads out on drum 5W R4- ohms, %, watt dial. With a flip of a switch, you keep 2D2I R5- 450,000 ohms, 5 %, I watt (see text) 250K S 1 5450K R6-4,000 ohms, 5 %, 5 watts S2 6 another dial reading the right time and RY VI SEE R4 R7 -1,500 ohms, 5 %, 5 watts TEXT R8-pot, 250,000 ohms, Ohmite CA2541 or your correct distance shows on the 4 240K equivalent, see text 93 third dial. R9 -10 ohms, 5 %, 5 watts (for 12 -volt S3 operation only) These are very fine, you say, but R TISOV 3 150K C 0f, 150 volts, oil filled OF -2 what does rallying want with all these 4K R2 VI -2D21 V2, 3 -0B2 (or Zener diode, see text) fancy gadgets ? The answer is simple. 5%,5W 3('.4 120K RY -spst, 5,000 -ohm plate- circuit relay You are traveling a route following in- V2 RI SI-single -pole 5- position switch R9 (Mallory 3215J or equivalent) structions which take you along only IOR I 62K S2 -spst pushbutton switch 082(2) 5W step by step. You have to be extra S3 -spst toggle V 5% alert or you may get lost! If this occurs, Counter -4 -digit resettable, 117 -volt ac coil NOT USED FOR (Production Instrument Corp. MDA-S4 -lISA no calculator or anything else can save 6V OPERATION or equivalent) you. This is why computers are so Case -8 x 10 %6 x 8 inches, sloping panel RI T05=IW (Bud C-1588 or equivalent) widely used. It allows more freedom to 11,3,4,5-5% Knob- S -to -I vernier with 0 -to -100 logging scale (National ACN or make sure you stay on course, and 260V =. 12V equivalent) Power supply, 260 vdc at 60 ma; 6 or 12 rol's dc maybe even enjoy a little scenery. Fig. 1- Schematic of computer using input as required (Heathkits VP-I-6 or VP -I -12 The computer described in the fol- or equivalent) thyratron. Separate power supply is Stop watch lowing paragraphs is a poor man's ap- needed. Miscellaneous hardware, sockets, etc. NOVEMBER, 1960 47

www.americanradiohistory.com ly 10 minutes, so dividing the counter reading by 10 gives you the number of counts per minute. This may be marked directly on the dial or later entered on a sheet of cross -section (graph) paper. Repeat the process with a new dial setting, five points lower than before. Continue until the entire range is cov- ered. Move the switch to position 4 and calibrate that range. Do the same for the remaining ranges. If you are going to use graph paper rather than marking the figures on the dial, number the bottom of a sheet (holding it horizontally) from 0 to 100. Number the side of the paper according to your count -per- minute determination. Now, plot your findings on the paper (make one graph for each range). You should have a neat arc traced by 20 points (Fig. 2). Join these (using a French curve). The vertical scale of the graph may be calibrated in miles per hour to save time in the rally. The number of counts per minute is equivalent to the number of 100ths of a mile you will travel per minute. For ex- ample, if you are moving at 12 miles per hour (average), at the end of one min- SI RI R2 R3 R4 85 S2 S3 NOT USED ute, you should have traveled 0.20 mile. If your counter is clicking away at 20 Rear view of computer. R5 is actually two resistors in series. counts per minute, at the end of that minute it will also read 00.20 (the last two digits on the counter read 100ths of a mile). 43 Transistor version 42 For those of you who want a unit of greatly increased accuracy, the tran- 40 sistor version in Fig. 3 should be suit- able. This unit is used by my friend Joe White, of Toronto, Canada. The separate 9 -volt (dry -cell) source for the multi - vibrator improves stability. The cost of 138 this version will be higher than that of a 36 the thyratron unit. No range switch is F- needed as one the control will vary the o count -per -second rate from about 0.6 to U 34 3.3 (10 to 60 miles per hour). The low - voltage counter required is somewhat higher priced. 18 T0 26 MPH 32 Calibrating the transistor computer is similar to calibrating the 2D21 version except only that one graph must be 300 plotted. 5 10 IS 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 LOGGING SCALE Using the computer When you receive your rally instruc- tions, the navigator looks up the speed Fig. 2- Sample graph produced on a table and converts when calibrating computer. Find it to counts counts- per -minute (or speed de- per minute (or skips that part if the sired) at left, go across to intersect graphs have already been calibrated in are and then drop line to logging mph). He or she finds the desired count scale at bottom. This gives setting rate (or speed) on the side scale of the for computer. graph. He then draws a horizontal line across the paper to intersect the arc. From the intersection, a vertical line is drawn E to the logging scale at the BOTTOM VIEWS bottom of the page. This is the computer setting. END RI -pot, 100,000 ohms, linear taper R2 -8,200 ohms, 10 %, /Z watt R3 -510 ohms, 5 %, V/2 watt C-40 4, 10 volts, tantalum VI -2N256 AUTOMOBILE V2 -2N 170 BATT S2 -o V3 -2N489 6 O 12V RY -spst, 6- or 12 -volt coil 0_-0 SI -spst pushbutton switch + S2 -dpst toggle switch Counter -4- digit, resettable with 6 -volt (or 12, O COUNTER a RELAY COILS TO MATCH depending on auto voltage) coil AUTO BATT VOLTAGE Fig. 3- Transistor version of computer Miscellaneous hardware, case, sockets, etc. uses . 48 RADIO -ELECTRONICS

www.americanradiohistory.com Sllbuarrirti Tohlliguos for 11A112M trair`

Systems can be designed to measure almost any quan- By ED BUKSTEIN * tity and transmit the figures any desired distance

BY definition, telemetering means the resistance of the varies able resistor is mechanically coupled to measuring at a distance. Remote with temperature, and since the ther- the bellows so that the voltage across measurement is used when the mistor is connected in series with a volt- resistor R3 is a function of air pressure. quantities to be measured are in- age source and a fixed resistor (R L) the This voltage controls the frequency. accessible or when it is not practical to voltage drop across R1 varies with tem- The subcarrier frequencies are so have an operator "take the readings." perature changes. If the temperature selected that the maximum allowable Telemetering apparatus is used exten- should increase, for example, the re- deviation (7.517) will not result in sively in missile and satellite equipment sistance of the thermistor wouki de- overlapping adjacent subcarriers. Table to radio back information on tempera- crease and a higher voltage appears I shows the standard subcarrier bands, ture, pressure, acceleration, fuel -flow across Rl. This voltage controls the allowable deviation and upper and rate, vibration, and other variables. frequency of SCO 1. The frequency of lower limits. These standards are vari- Each of these variables is converted to the oscillator at any given instant may ously referred to as RDB, IRIG or an electrical signal and used to modu- therefore be 400 cycles, or above or be- IRTWG standards. The initials desig- late a transmitter. A system of subcar- low this value, depending upon the nate the organizations which contrib- rier oscillators is used, so that all of the temperature (assuming SCO 1 is a uted to the establishment of the stand- telemetered information can be trans- band -1 oscillator. See table.). The ther- ards (Research and Development Board, mitted within a single radio channel. mistor in Fig. 1 is connected as part of Inter -Range Instrumentation Group and a voltage divider, but frequently- it is Inter -Range Telemetry Working Group). Transmitting systems used as an arm of a bridge circuit. As shown in the table, five opftional The block diagram of a typical tele- SCO 2 responds to changes of humid- bands (A through E) permit deviations metering system is shown in Figs. 1 ity. The humidity- sensing element is a of ±1511 if adjacent bands are not and 2. Only three subcarrier oscillators coating of lithium chloride on a glass used. are shown, but many more may be used. or plastic base. The coating absorbs The frequency -modulated outputs of Each of these oscillators operates at a moisture from the surrounding air and different center frequency. The fre- its resistance changes accordingly. The quency of each oscillator varies in voltage drop across fixed resistor R2 Subcarrier Bands and Limits accordance with changes in the quan- therefore depends upon the humidity tity to be telemetered. The first sub - and controls the frequency of SCO 2. Center Maximum Bond Li,rita Band Frequency Deviation in 1 1) is carrier oscillator Fig. (SCO Information regarding air pressure (cps) (percent) Upper lower used to telemeter temperature informa- is also telemetered. An increase of ex- tion. A thermistor (negative- tempera- ternal pressure (or decrease of internal 400 ±7.5 430 ture coefficient resistor) is used as a pressure) compresses the bellows. A de- 2 560 602 518 3 730 785 675 temperature- sensing component. Since crease of external pressure (or increase 4 960 1,032 008 of internal pressure) allows the bellows 5 i,300 1,398 I ,M2 s Northwestern TV & Electronics Institute, Minneapolis, Minn. to expand. The arm or slider of a vari- 6 1,700 1,828 1,512 7 7,300 2,473 2,127 8 3,000 3,225 2,775 9 3,900 4,193 3,637 10 5.400 5,805 4,995 THERMISTOR 11 7,350 7,901 6,59 12 10,500 11,288 9,7'12 13 14,500 5588 13,42 RI 14 22,000 23,650 20,350 15 30,000 32,250 77,750 16 40,000 00 43,000 37,030 17 52,500 36,440 48560 HUMIDITY 18 70,000 ns,250 61, 750 ELEMENT REACTANCE MIXER A 22,000 ±15 25,300 18,730 MOD B 30,000 34,500 25,530 40,000 46,000 31,030 R2 C D I 52,500 60,380 44,00 E 70,000 10,500 53,510 SCO SUBCARRIER OSC !

BELLOWS Sands A through E. are optional end rad >e used in place of numbered bards by q adjacent bands as follows: Bond Used Omit Boron A 15 and E Fig. 1 -Block diagram of a three - 14, 16 A C R3 C 15, I:, E. P channel telemetry transmitter. D 16, tE C E E 17 and D

NOVEMBER, 1960 49

www.americanradiohistory.com BAND -PASS SUBCARRIER DRIVER

FILTER I DISCRIM I AMPL

RECORDING PENS

TEMP SUBCARRIER DRIVER HUMID FILTER 25S DISCRIM 2 AMPL PRESS

MOTOR- DRIVEN STRIP CHART BANDPASS SUBCARRIER DRIVER FILTER 3 DISCRIM 3 AMPL

Fig. 2 -Block diagram of a three -channel telemetry receiver. The output from each channel is recorded on a paper tape.

capacitance of this two -plate capacitor S te- BLOWS -.i will therefore vary with pressure s MECHANICALL changes. MOVABLE If this capacitor is used in LINKAGE i the tank circuit of an oscillator, pres- SCORE sure changes will be converted to fre- MOVABLE PLATE a quency changes. FIXED PLATE Alternatively, the bellows can be used Geotechnical Corp. to control the OSC TANK OSC TANK position of a core with a Channel 5 voltage -controlled oscillator. respect to a coil. Pressure variations 6 produce inductance changes. Again, the the subcarrier oscillators are mixed and inductance can be part of an oscillator applied to a reactance modulator stage. tank circuit. A Bourdon tube is fre- The main carrier is therefore fre- quently used in place of the bellows. As MECHANICAL quency- LINKAGE TO modulated by the frequency - shown in Fig. 3 -c, this consists of a VARIABLE modulated subcarriers. For this reason, bent, hollow tube closed at one end. An RESISTOR, the technique OR is sometimes referred to increase of pressure (in the tube) tends FLATTENED CAPACITOR as FM /FM telemetry. Transmission is to straighten it and the resulting me- c generally in the 216- to 235 -mc band chanical motion can be used to vary the and power output of 3 to 50 watts. value of a capacitor, inductor or re- The receiving (ground- station) equip- sistor. MECHANICAL LINKAGE TO VARIABLE R,LOR C ment (Fig. 2) includes an FM receiver. The accelerometer consists of a The output of the second detector (dis- spring- supported weight known as a criminator) consists of the varying seismic mass. In some models, the subcarrier frequencies. Bandpass filters accelerometer case is filled with oil to CASE are used to separate the individual sub - prevent excessive vibration of the mass. carriers which are then amplified and The position of the mass with respect applied to the subcarrier discriminators. to the case depends upon the rate of SPRING-SUPPORTED WEIGHT ( SEISMIC MASS) Since a discriminator is a frequency - acceleration. If the accelerometer is d to- voltage converter, each subcarrier mounted in a missile, for example, the discriminator produces a dc output that mass will move backward when the mis- varies with changes of the telemetered sile accelerates (for the same reason quantity. The do output of discrimina- the driver of an automobile is pushed PRI SEC 1, tor for example, will vary with against the back of the seat when the VARIABLE changes of OUTPUT temperature; the output of car is speeding up). When the missile C discriminator 2 with humidity; etc. decelerates, the mass moves forward in SEC o The discriminator outputs control re- its case (just as a driver is thrown cording pens. These resemble ordinary RESISTANCE WIRE forward when the brakes are suddenly CEMENTED TO PAPER meter movements except that the point- applied). The CORE POSÌTION CONTROLLED BACKING mass of the accelerometer BY BELLOWS, BOURDON TUBE, ers have been replaced by small light- may be mechanically coupled to a vari- ACCELEROMETER, ETC f weight pens. Writing on a motor- driven able resistor, capacitor or inductor. e paper chart, they indicate variations of As shown in Fig. 3 -e, the differential temperature, humidity, etc. transformer contains a movable core Transducers and two secondary windings connected in series. The secondaries are 180° out As a first DISSIMILAR OUTPUT step in the telemetering of phase so that normally their voltages METALS process, the quantities to be telemetered cancel and there is no output. But if must be converted to some type of elec- the position of the core is changed, the JUNCTION trical signal. The components used for coupling to one secondary is increased this purpose are referred to as trans- and to the other secondary decreased. ducers, data pickups, pickoffs, end in- Under these conditions, the voltages struments or sensing elements. induced in the two secondaries are no DC GENERATOR In Fig. 1, for example, the thermistor longer equal. The net output voltage functions as a temperature-to- resist- will therefore have an amplitude and ance transducer, the bellows -controlled phase determined by the amount and rheostat ROTATING serves as a pressure-to- resist- direction of core movement. The posi- SHAFT MECHANICAL - + ance transducer, and the humidity ele- tion of the core can be controlled by a COUPLING OUTPUT ment provides humidity -to- resistance bellows, Bourdon tube, accelerometer or á conversion. Several other techniques any other component providing me- are illustrated in Fig. 3. chanical motion. Fig. 3 - Transducers: a - bellows -con- trolled capacitor; bellows -controlled As shown, a bellows responding to The strain gauge consists of a piece b- pressure changes inductor; c- Bourdon tube; d- accel- can be used to control of resistance wire cemented to a paper erometer; e- differential transformer; the spacing between two metal plates, backing. Strain (dimension change) in f-strain gauge; g- thermocouple; li- one fixed and the other movable. The the structure to which the gauge is tachometer-generator. 50 RADIO -ELECTRONICS

www.americanradiohistory.com quency determined by the voltage ap- plied to its input terminal. As shown in Fig. 5, this type of subcarrier oscilla- tor employs a multivibrator circuit. The grid resistors of the multivibrator are connected to the plate of the control tube rather than being grounded as in the conventional multivibrator. The plate voltage of the control tube therefore varies the bias of the multivibrator and consequently controls the frequency of oscillation. The control tube is in effect a dc amplifier for coupling the trans- ducer to the multivibrator. A small change of input voltage (from the transducer circuit) can therefore pro- duce a relatively large variation of multivibrator frequency. Trimmer ca- pacitors are sometimes shunted across the coupling capacitors of the multi- vibrator to serve as center- frequency adjustments. As an alternative, controls (Rl and 2) such as those shown in Fig. 5 may be used. The two Geotechnical Corp. are interacting in effect and are used Multiplexer containing seven plug -in subcarrier oscillators. to set the center -frequency as well as the deviation limits of the oscillator. SATURABLE CORE Characteristically, the multivibrator OSC TANK attached causes the wire to stretch. As produces a square -wave output. The the wire becomes longer and thinner, 1 harmonic components of the square its resistance increases. The strain \? 7 wave contribute nothing to the tele- gauge is connected as part of a bridge CONTROL LOAD metered information and may interfere circuit so that the degree of unbalance (DC) WINDING (,AC) WINDING with higher subcarrier channels. A low - of the bridge is a measure of the me- Fig. 4- Saturable reactor used as a vari- pass filter is therefore used to attenuate chanical strain in the structure being able inductor. the harmonics while allowing the fun- tested. Strain gauges are often mounted ance or capacitance of the tank circuit damental sine -wave frequency to- pass on the skin and structural members of and varies the output frequency. through. The filter is followed by an a missile. A variation of the inductance -con- amplifier stage, sometimes convected The thermocouple is a temperature- trolled oscillator uses a small saturable as a cathode follower (shown) to pro- to- voltage transducer. Consisting of two reactor as the tank coil. The saturable vide a low- impedance output. dissimilar metals, it produces a voltage reactor, as shown in Fig. 4, has two A commercial model of a vo.ltage- whose amplitude is determined by the windings: the control or dc winding controlled subcarrier oscillator is shown junction temperature. This voltage is and the load or ac winding. Passing dc in one photo. An input of ± 2.5 volts to relatively small so the thermocouple through the control winding will satu- this unit will produce a frequency shift must be followed by several stages of rate the core to an extent determined of ±7.5%. The control knobs shown are amplification. As compared to the ther- by the magnitude of the current flow. used to adjust the center -frequency and mistor, the thermocouple has the advan- Since the degree of core saturation de- the deviation limits. A multiplexer con- tage of responding faster to tempera- termines the inductance of the ac taining seven of these subcarrier oscil- ture changes. winding, the saturable reactor can be lators is shown in the other photo. The tachometer generator is a small used as a variable inductor. When the A transistor version of the voltage - do generator used for measuring the ac winding is connected in the tank controlled oscillator is shown in Fig. 6. rate of shaft rotation. The generator is circuit of a subcarrier oscillator, the The transducer circuit is coupled to mechanically coupled to the shaft whose oscillation frequency depends upon the the multivibrator through an enni_ter speed is to be telemetered, and the out- current flow through the control wind- follower. By controlling the bins of put voltage of the generator is there- ing. the multivibrator, the emitter- foloaver fore a function of the rpm of the shaft. The voltage -controlled oscillator, as stage determines the frequency of An ac generator may be used if rpm - the name implies, oscillates at a fre- oscillation. END to- frequency conversion is desired. CONTROL LOW -PASS FILTER MULTIVIB CATH FOLL Subcarrier oscillators TRANSDUCER TUBE Subcarrier oscillators are classified R2 according to the method used to con- RI trol the frequency -voltage- controlled, resistance - controlled, inductance -con- trolled or capacitance- controlled. The resistance -controlled subcarrier oscillator generally employs an R -C B +' 8+ rIB+ tuned circuit such as the Wien bridge or Fig. 5- Voltage- controlled oscillator. Control tube phase -shift oscillators. The oscillation varies bias and therefore frequency of multivibrator. frequency is determined by the time LOW-PASS FILTER MULTIVIB OUT constant of a resistance capacitance EMITTER feedback network. A variable- resistance FOLLOWER transducer (thermistor, bellows -actu- FROM ated rheostat, etc.) can therefore be TRANSDUCER T used as a frequency- determining ele- ment of the circuit. Inductance- and capacitance-con - trolled subcarriers are usually gener- ated by a Hartley oscillator circuit. The transducer controls either the induct- Fig. 6- Transistorized voltage -controlled multivibrator schematic. NOVEMBER, 1960 51

www.americanradiohistory.com PICKUPS Part Ill -The ESL 099 Micro /Flex, Empire 88, Pickering 380, Shure M2I2 /M2I6, Stereotwin

210/D and Fairchild SM- I

By JULIAN D. HIRSCH TWO moving -coil stereo cartridges that no motion is imparted to coil B, were described in last month's in- which is held at both ends by the latex stallment of this series. Since that support blocks. The left side of the article was prepared, information Micro /Flex system rotates with the sty- has been released on another new mov- lus, causing coil A to rotate in the mag- ing -coil cartridge, the ESL C99 Micro/ netic field passing through it. This gen- Flex. erates a voltage in coil A proportional In many ways this unit resembles the to the stylus velocity. Similarly, modula- ESL C99 Micro /Flex Cartridge. ESL C100 Gyro Jewel (October 1958, tion of the outer groove wall generates page 48). It incorporates the D'Arson- a voltage only in coil B. val type of moving coil which has char- Although this coupling system func- acterized all ESL cartridges. The C100 tions very much like that of the C100 employed an ingenious gimbal structure Gyro /Jewel, it is more rugged and sim- which allows each coil to rotate inde- pler to manufacture. The improved pendent of the other. The delicacy of ruggedness makes the C99 suitable for this design is reflected in its relatively use in good record changers. high price ($69.50). The compliance of the moving system In the C99, the basic operating fea- of the C99 is 5 x 10 " cm /dyne in both tures of the C100 have been retained, vertical and lateral planes. Its dynamic with a simpler mechanical design which mass is 2.5 mg. The recommended track- permits a lower selling price. ing force is as low as 2 grams in a well One of the photos shows the ESL C99 designed arm, though somewhat higher stereo cartridge. The cantilever stylus forces may be required in some arms. shoe is made of a black plastic mate- The output of the ESL C99 is very rial. The curved portions visible at the low (0.6 my at 10 cm /sec stylus veloc- hase of the stylus shoe are part of the ity) and a stepup transformer is re- Pickering 380 and its slip -in stylus as- Micro /Flex coupling system. sembly. Fig. 1 shows how the Micro /Flex sep- arating system couples the stylus to the two coils, each wound with 20 turns of very fine precious -metal alloy wire (only D'ARSONVAL S/ GAL VA NOM ETER-----44, a fourth the diameter of a human hair). ELEMENTS The long, narrow coils are positioned between a pair of magnetic pole pieces located it front of and behind each coil. Each end of each coil form (armature) is supported by a latex holding block, MICRO -FLEX which also serves as a damping element. FLEXIBLE SEPARATING LEVER SYSTEM The Micro /Flex separating system is SYSTEM a molded plastic piece which is split down the middle. At the bottom, the two sections are joined by a thin flexible OUTER WALL y,:!`,: INNER WALL plastic lever to which the base of the MODULATION MODULATION stylus shoe is attached. Modulation of the inner wall of the STYLUS Stereotwin 210 /D. Stylus assembly is de- record groove moves the stylus up and Fig. 1 -The Micro /Flex separating sys- signed for simple replacement. to the right. The flexible lever bends so tem used in the ESL C99. 52 RADIO -ELECTRONICS

www.americanradiohistory.com quired for practically all installations. A pair of the ESL TM -100 transformers is recommended. The frequency re- sponse is 18- 20,000 cycles, ±2 db, and the channel separation is 20 -25 db over most of the audio range. The price of the ESL C99 is $49.50. A moving magnet is the generating element in the cartridges described below. Most moving- magnet cartridges have relatively high output voltages, and rugged moving systems which usually allow the stylus to be replaced by the user. All except the Fairchild SM -1 use a rectangular bar magnet made of a ferrite material which has low mass and good magnetic properties. Although the various cartridges differ in details of coil and pole -piece design, as well as specific materials and stylus support structures, they are similar to the first unit to be described, so its assembly drawing will suffice to explain their operating principles. Empire 88 This cartridge has a bar type moving The Shure M212 arm and pickup. magnet, with mass concentrated close to the pivot axis, giving a low moving mass when referred to the stylus tip. Fig. 2 is an assembly drawing of the Empire 88. groove wall controls the output of the The rectangular bar magnet is mounted rear pair of coils. in an elastomer damping material which A pair of coils is used for each chan- positions it between the four pole pieces. nel. The coils are so interconnected that Its entire length is fastened to the light the effects of external hum fields are aluminum stylus shoe, which is angled cancelled. In addition, a mu -metal shield for stiffness. A fine support wire runs encloses the front of the cartridge, to the front of the stylus assembly to where the coils are located. hold the shoe and magnet in a definite An interesting feature of the Empire position, and to provide the compliance 88 cartridge design is that the repktce- for the moving system. able stylus assembly contains the quad - When the stylus is moved by modula- rature pole -piece structure shown in tion of one or the other of the groove Fig. 2. The four cylindrical pole pieces walls, the magnet rocks about a pivot which pass through the coils protrude point located approximately halfway be- slightly from the cartridge body and tween the front and rear coils. This contact the flat pole pieces when the varies the flux through the correspond- stylus assembly is mounted to the ar- ing pair of coils generating a voltage fridge body. This design insures that in them. In Fig. 2, modulation in the all critical portions of the cartridge are inner groove wall produces an output The Empire 88. Remove screw to replace fully protected and are replaced as a in the coils nearest the stylus; the outer stylus. unit when the stylus is replaced_ The stylus assembly is held in place by a HUM -BUCKED COI L SYSTEM single screw, visible in the photo.. Compliance of the Empire 88 is 5 x 10-° cm /dyne, in both vertical and lat- eral planes. The moving (dynamic) mass is claimed to be only 0.7 mg. Its output is 5 my per channel at average recording levels. Channel separation is greater than 20 db. Frequency respcnse is 20- 20,000 cycles ±2 db. The recom- QUADRATURE mended tracking force is 2 to 5 grams. POLE The price of the Empire 88 is $24.51 STRUCTURE Pickering 380 Unlike previous Stanton Flu-Live cartridges (made by Pickering), which were variable -reluctance types, the new 380 Collectors Series use moving mag- ELASTOMERS nets. Although the principles of oper- DAMPING ation of the Pickering 380 are identical MATER IAL to those of other moving -magnet car- SUPPORT tridges, several unique design features WIRE MAGNET which are not immediately obvious are incorporated. The photos include a Pickering :380 cartridge and one of the plug -in stylus INNER OUTER assemblies. The stylus assembly cpn- WALL'- 7 WALL sists of a brass tube containing a rec- Fig. 2-Assembly drawing of the Empire 88. tangular bar magnet, surrounded by a NOVEMBER, 1960 53

www.americanradiohistory.com separation at 1,000 cycles. Its output is fairly high, about 9 mv at 10 -cm /sec stylus velocity. Stylus compliance is very high, 9 x 10 cm /dyne in both lateral and verti- cal planes. The needle -tip mass is 1.3 mg. Tracking force is adjustable be- tween 1.5 and 2.5 grams. The price of the complete Shure M212 Stereo Studio Dynetic pickup is $89.50.

Stereotwin 21 0/D The Stereotwin 210 /D is an improved version of the Stereotwin 200 (Novem- ber 1958, page 88). The original Stereo - twin 200 had three solder lugs for its output terminals. The new 210 /D has four terminals which accept -on Fig. Replaceable stylus assembly of Shure M212 clip con- 3- cartridge. nectors as do most other cartridges. The stylus structure has been refined damping material. A short, stiff alumi- recognized as one of the finest stereo and made num tube more rugged. extends from one end of the cartridges, and the M7D (March 1959, The Stereotwin 210 /D is fully en- magnet, and carries the 0.7 -mil dia- page 84) is a lower- priced version of cased in mu -metal mond and has extremely stylus at its far end. The plastic this cartridge. low hum pickup. Its output is also very V -Guard cone serves as a handle for The integrated pickup, M212, uses high, about 13 mv per channel. inserting or withdrawing the stylus, the same internal structure as the M3D The cartridge assembly features a and protects it if the arm is dropped and M7D, packaged in a very compact simplified mounting system. The car- onto the record surface. form and designed to operate only in a tridge is removed from its mounting The coils and pole pieces are firmly special snakelike arm. It is straight, encapsulated clip, which can then be mounted in an within the body of the with the necessary offset angle built arm without difficulty. The cartridge cartridge, which is shaped like a com- into the cartridge (the stylus is mounted then snaps into the pletely clip. symmetrical pyramid. At its at an angle to the axis of the arm). The The stylus assembly, visible in the tip is a small hole into which the brass arm is free to move laterally, but is photo, includes the moving-bar tube of the magnet stylus assembly fits. Ex- constrained vertically. Only the extreme and damping material common to most tending along the length of this hole forward portion, containing the car- moving inside magnet cartridges. It can be the cartridge are the four pole tridge, can move vertically. It is raised slipped in or out of the cartridge with- pieces. They are curved to fit the shape from the record surface by pressing out tools. of the brass tube, and to obtain maxi- The design the mum magnetic of mounting clip al- coupling to the magnet LEFT-CHANNEL. lows the cartridge to be positioned for within the tube. POLE PIECES correct The stylus position in both changers body of the Pickering 380 car- and transcription arms. Slots in the tridge is fully enclosed with a one -piece clip permit drawn sliding it forward or back- mu -metal shield, and the rear ward to obtain the correct stylus over- is capped with a piece of mu -metal hang for minimum through which MAGNET tracking error. Not the terminals protrude. visible in the photo are two slots in the The result is virtually perfect shielding end of the clip, which permit adjusting against external hum fields, both elec- STYLUS the angle the stylus makes with the tromagnetic and electrostatic. SHANK record surface. is Output exceptionally high, 20 mv The Stereotwin 210 /D will 10 track at at cm /sec stylus velocity. Frequency 3 to 4 grams in response a good arm, or 5 to 6 is within 2 db from 20 to 20; RIGHT- CHANNEL grams in a record changer. The price 000 cycles. Channel separation is 25 db POLE PIECES or better through most of the audio -c-STYLUS range. Fig. 4- Moving -magnet assembly used The 380 is available with a choice of in the Shure cartridge. two styli, for transcription arms or for record changers. The 380 -A, designed down on the plastic button protruding for transcription arms, tracks at 2 to 5 from the top of the arm. grams. The 380 -C stylus has less compli- Fig. 3 shows the replaceable stylus ance and tracks at 3 to 7 grams. Pick- assembly of the M212. The thin alumi- ering does not publish compliance fig- num member holding the stylus is fas- ures, but experience with the 380 -A tened at its other end to the rectangu- shows that it will track very well at 2 lar cross -section bar magnet. The mag- grams, indicating a very high compli- net is surrounded by an elastomer ance. The Pickering 380 -A sells for damping material. A fine wire (not vis- 834.50, and the 380 -C sells for $29.85. ible in Fig. 3) extends from the end of the stylus shoe to the body of the Shure M2 I 2/M2 16 stylus housing, to provide stiffness for The Shure M212 is the stereo coun- the moving system. terpart of the well known Studio Dy- The internal structure of the Shure netic pickup, model M12. The M216 is cartridge is shown in Fig. 4. It is very identical to the M212 except for the similar to most of the moving- magnet length of the arm, which will accom- cartridges we have described. The pole modate 16 -inch records. pieces are within the body of the car- Shure introduced monophonic moving - tridge, while the stylus shank and mag- magnet cartridges to the American hi -fi net are in the removable stylus assem- scene a few years ago, and have con- bly. tinued the same approach to the design The frequency response of the Shure of stereo cartridges. The Shure M3D M212 pickup is rated at 20- 20,000 cycles Fig. 5-How the spherical magnet in the (November 1958, page 83) is widely - 2.5 db, with more than 20 -db channel Fairchild SM -1 works. 54 RADIO -ELECTRONICS

www.americanradiohistory.com NEW for RADAR POLE PIECES TWO accessories that increase the value AND COILS of radar have recently been an- nounced. One, made by Intercontinental Electronics, Mineola. N. Y., is a new COPPER type of indicator system that removes SHIELD stationary and slow -moving objects from the trace. It uses two storage tubes in cascade as comparison memory gates to eliminate any fixed or slow - MU-METAL moving targets. The difference can be SHIELD clearly seen in the photos. Photo 1 is a normal radar trace. Photo 2 is a radar picture of the same area, but with the nonmoving targets eliminated. Note how clearly the moving targets appear now. SPHERICAL The second radar aid was announced MAGNET by Lockheed Electronics, Plainfield, N. STYLUS 04 J. It is similar to a unit described in the November, 1959, issue of RADIO - Fig. 6- Exploded view of the Fairchild SM -I. ELECTRONICS, page 6. Both are designed to eliminate spurious signals known as "fruit" from radar displays. It is espe- of the 210 /D has been reduced sub- balance of flux lines is disturbed. In Fig. cially useful with radar designed for stantially compared to its predecessor. 5, the stylus has been displaced verti- IFF (Identification Friend or Foe) It sells for $34.50. cally, moving the "equator" of the mag- and ATC (Air Traffic Control). The net into the position shown by the unit assists in locating and identifying Fairchild SM -I dashed line. Some of the flux lines, aircraft by preventing a display of The Fairchild SM -1 is a moving-mag- shown as light dashed lines, still bridge spurious signals caused by overinter- net cartridge of radically different de- across the pole pieces and do not link the rogation, clutter, weather or other sign, compared to the ones previously coils. Others, shown as dash-dot lines, phenomena. In military applications it described. enter one pole piece and pass down will separate targets from interference, A sphere of Indox V (a magnetic through the coils to return via the oppo- intentional or otherwise. END ceramic material) is the magnet in the site pole piece. SM -1. The sphere is magnetized along The exploded view of the SM -1 car- an axis parallel to the length of the tridge (Fig. 6) shows how the pole cartridge. Fig. 5 shows the orientation pieces pass through the coils and ex- of the magnetic sphere between the tend forward to the "equator" of the four pole pieces, and the distribution of spherical magnet. As the ball rotates the flux lines. In the neutral position slightly due to the stylus following a of the stylus, the flux lines pass through stereo groove, there is a net change of the tips of the pole pieces on their way flux linkage through the four coils and from the front N of the magnet to the a corresponding generation of stereo rear S. Since the "equator" of the output signals. sphere is symmetrical with respect to The ball magnet is mounted in a the four pole pieces, there is no tend- damping ring which damps vertical mo- ency for flux to pass down the pole tion, and is supported at the sides by pieces and link the coils. damping blocks to control lateral reso- If the stylus is displaced from its neu- nances. The damping ring and blocks tral position, the ball rotates and the are shown in Fig. 7. The stylus bar of the Fairchild SM -1 is of tubular construction, for maximum PHOTO I LATERAL torsional rigidity. Since the ball mag- DAMPING BLOCKS net pivots about an imaginary point at its center, the moving mass referred to the stylus tip is very low. Lateral com- pliance of the SM -1 is approximately 6 x 10-° cm /dyne, and its vertical com- pliance is approximately 4 x 10-° cm/ dyne. To reduce the effects of external hum fields, a shorted turn of copper sur- rounds the coils, and the entire car- tridge is surrounded by a mu -metal shield. The output voltage of the SM -1 is high, 22 my for 10 -cm /sec stylus ve- locity. It is designed to track at 3 to 4 grams force. The price of the Fairchild VERTICAL SM -1 cartridge is $34.95. DAMPING This sums up our current survey of RING stereo phono cartridges. As additional Fig. 7- Damping ring and blocks used units appear, they too will be described. with the spherical magnet. Look for them in future issues. END PHOTO 2 NOVEMBER, 1960 55

www.americanradiohistory.com ECONOMICAL HIGHWAY FM

A small FM radio (or tuner) may be converted to a I2 -volt FM tuner

By JOHN J. BORZNER

MOST automobiles have built -in especially the Graneo. The Heath has it run a few days before the conversion. AM radio. For the individual age, which is helpful when driving When you are convinced that it is oper- who wants to listen to an FM through areas where signal strength ating satisfactorily, start the conver- station while driving, there varies- cities with many tall steel - sion. Remove the loudspeaker, output has been just one "choice" (assuming frame buildings. transformer and the audio output tube his car does not already have an FM Both sets are powered by a small, (5005). Snip the two colored leads to radio) : buy a commercial FM receiver. dependable transistorized power supply. the output transformer close to their Most commercial sets cost a good deal It puts out about 125 volts dc for the source. Ground the black lead which more than the average man wants to Graneo and 250 volts for the Heath. runs from the volume control to the pay. Now, for $40 (much less if you al- Graneo uses three 12 -volt tubes (which output side of the transformer. ready have a small FM radio), you can present no problem and one 19 -volt tube In the space previously occupied by add FM to your car. which performs satisfactorily on 12- the speaker and output tube, mount the What are the advantages of FM? volts. Later models have a 14 -volt tube transistor power -supply transformer, Distortion is less, signals are much in place of the 19 -volt one). The Heath a Triad TY -68S. Then, in any conven- cleaner, there is much more good music set uses six 6 -volt tubes which can be ient spot, mount the two transistors. on FM than AM; there are fewer readily hooked up as three 12 -volt They will not require a heat sink, even commercials and the audio -frequency strings. under sustained use. The collector in the range of most FM stations is better Before building the power supply, de- 2N256 is tied internally to the case so than that of AM stations. cide which radio you are going to use. you must insulate the transistors from I have taken two FM receivers and The supply can be built into either each other and from the mounting plate. converted them to 12-volt -powered tun- cabinet very neatly. The space used by, Wire the power supply according to ers. One is the Graneo 601 FM table the rectifier tube and transformer in Fig. 1. RECT 3 and 4 are not used for radio; the other is the Heathkit FM- the Heath is more than adequate for the Grañco. 3A tuner. the transistor power supply. In the Ground the center connector of the The power supplies of both units were Graneo (which uses a selenium recti- power -supply rectifiers to the chassis. removed and replaced with a transistor - fier), the loudspeaker, output trans- The B -plus lead is simply soldered to oscillator B -plus supply. Since one is a former and audio output tube are re- the output side of the selenium recti- tuner, few other changes are necessary. moved to make room for the mobile fier (Fig. 2). The power supply output The audio output stage and speaker power setup (see photos). is filtered by the power- supply filter in were removed from the radio. The audio the receiver. signal is fed to the car's AM radio Granco conversion Now rewire the heaters for 12 -volt audio system. The Graneo radio is ready to play operation (Fig. 3). There is no need to Both sets are quite free from drift, when received. I suggest that you let remove any components. (Watch bat- 56 RADIO -ELECTRONICS

www.americanradiohistory.com RI-68 ohms, I watt R2 -270 ohms, I watt All resistors 10% VI, 2 -2N256 or equivalent T-transistor oscillator power transformer, 12 volts to 250 volts, 65 ma, centertapped (Triad TY -68S or equivalent) RECTI, 2, 3, 4 -500 ma, 130 volts silicon rectifiers (Sarkes Tarzian M500 or equivalent) F-SFE 32 -volt, 9- ampere fuse and in -line fuse holder

RECT 1,2,3,4 500 MA EACH

Fig. 1 -Power supply schematic. RECT 3 and RECT 4 are not used with the Granco and the secondary center tap is not used with the Heath.

1051 j 90051 I

1

1 1 IOOMA + 4W LINE 1 5 0 i 1 3A /IW ) 150V ISOV i 0---0 FUSISTOR - _

www.americanradiohistory.com of the heaters and ground the chassis to see whether the tubes light (see pre- vious warning on heater grounds.) You will not need the aluminum plate described above for mounting the sock- ets and jacks on the back of the cabinet. Since this set was originally SIMPLE designed as a tuner, the phono output jack is already installed. The antenna coupler can easily be changed to the automotive type jack. Be careful to note polarity. The antenna changeover switch can be located on the front panel. SWEEP With the Heath set, volume is con- trolled by both the AM and FM units, so make sure that both are turned up when testing. General GENERATOR Both sets are hooked up to the car in the same manner. The auto antenna lead will serve as a ground (by means of the cable shield. Power is taken from the cigar lighter or ignition switch. Attach the audio output cable to the car radio's input jack and turn on both USES sets. The power supply in the converted set may appear to race or take off until the heaters warm up; however it will stabilize once operating temperature is reached (usually 1 minute). If your set showed a tendency to drift while warming up in the preconversion VARICAP test, you will have to allow some time for the set to settle down. This is usu- ally not 15 over minutes even in the By MORRIS BARRON

N°47 PILOT LAMPS UNIQUE component from the me if and discriminator FM receiver 4 4 4 semiconductor family promises alignment. The photograph shows how 6807-A 6C86 6AL5 to provide a new and better the necessary circuit components can fit 5 3 3 39 41/2W technique for voltage - con - into an instrument, and how little space 4 3 y 4 trolled tuning and for frequency modu- they require, making this modification 6U8 6CB6 6C4 lation in particular. The Varicap,* a easy. Fig. 1 is the schematic of the 5 4 3 voltage- , should prove sweep frequency- modulation circuit. useful and effective in building or de- In working out the design of this signing new equipment or modifying circuit, the details were considered in Fig. 6 -The Heath heaters are in series- older equipments. It is actually a diode the following order: first, the sweep parallel. A resistor is required across whose capacitance changes in accord- voltage the 6C4 heater. frequency of 60 cycles was ance with the applied bias voltage. established. It is the standard used for Among its other good attributes, the many other instruments and test pro- poorest sets. This completes the con- Varicap voltage- variable capacitor is cedures used for this purpose. Next, versions. These are reasonably simple inexpensive, costing no more than an the chart of Fig. 2 was consulted to changes and sets that do not function ordinary receiving tube. determine the required modulation volt- properly can be usually traced to trou- There is a real need for a good but age. The chart shows the voltage bles in the receiver itself. simple and inexpensive FM alignment capacitance relationship for all Varicap tool in the service technician's or ex- diodes regardless of their initial capac- Noise perimenter's shop. An rf signal genera- itance. It was found that the generator's tor was modified with the help of this 6.3 -volt filament supply was not only There should be no interference from handy component, and convenient but the AM radio because the auto antenna demonstrated its could provide ample aptness and simplicity of use. The 20 -pi voltage, 17.6 volts is connected to the FM set. When the f peak to peak. voltage -variable capacitor- was used to That voltage is more than enough for car radio is not connected to an external modify its sensitivity is reduced to an ordinary signal generator to the required frequency deviation. How- antenna, provide a sweep -signal source 10.7- ever, the near zero. However, it doesn't hurt to for exact amount of frequency swing an oscillator is by set the AM radio to a quiet spot on the of determined the L -C of the coil capacitor com- dial. If a crackle or ignition noise is ratio * Trademark for Pacific Semiconductors Inc. bination which produces the 10.7 -mc heard, better shielding of the FM set voltage- variable capacitor. frequency. Thus, for a or antenna may be required. While FM 1' Type V -20, capacitance at -4 volts, 20 µµf. tuning condition radios are usually noise free, they are susceptible to motor noise. Proper shielding is the answer to almost all these problems. Your car will pose its BENCH own problem which careful custom in- A simple circuit that will make an AM signal generator into a sweep stallation can solve. gen, with a deviation that can be as great as 600 kc. By using reasonable care in building The unit worked exactly as specified by the author. Sweep patterns and converting, the experimenter will as observed on scope screen were sharp with rapidly rising front edges be rewarded with many enjoyable hours and rapidly falling rear edges. of pleasing highway FM. END

58 RADIO -ELECTRONICS

www.americanradiohistory.com Make a narrow -sweep generator for FM if alignment out of your own AM sig gen

where the tuning capacitor of the RI- 150,000 ohms, I,12 watt 225 R2 -100 ohms, potentiometer signal generator is at a minimum, the CI -.005 µf, paper C2 -.002 µf ceram'c voltage -variable capacitance produces a 1,1] 200 V- 20- Varicap V -20 relatively large frequency change, up SI- switch, spst, optional to 600 kc. If the 10.7 -mc point occurs at S2- switch, spst, toggle BATT -6 -volt, tapped F 175 the low -frequency end of the band (tuning capacitor fully meshed), the á 15C voltage -variable capacitor produces a 0PTI0NA!. CI 4 relatively small amount of frequency SI 4.5 -6V RI .005 i z 125 change, no more than 60 kc. -NVM+lt-o-- LI R2 ° 9+ S2 150K + If you wish to use your signal gen- 6.3V 10011 TUNING ci 60'G . á its IOC erator without changing calibration, SOURCE SWEEP WIDT I- f the circuit of Fig. 1 can be switched in T002 Z or out very simply. For recalibration NOiE- V-20 F 7 of the 10.7 -mc point, within the band, LI- FOR 10.7 MC BAND VARICAP ú OF SIG GEN using the voltage -variable capacitor, a o_ U 50 shorted turn was used to overcome the Fig. 1- Schematic of the circuit that 0 -2 -4 -6 -8 -ID -12 excess static capacitance of the circuit, modifies a signal generator. BIAS VOLTS (DC) even though the calibration trimmer AIL was removed from the tuning band. Fig. 2 - How a Many methods can be used to recali- Varicap's capaci- brate the signal- generator band, and tance varies with find a good 10.7 -mc point. There are voltage. also various procedures for FM align- ment. These will not be discussed here. The information is available in stand- ard texts, and experienced service tech- nicians, advanced experimenters and technicians will have no difficulty with these problems. Another very good feature of using a voltage- variable capacitor is that a 60- cycle phase shifter, normally needed for the oscilloscope horizontal sweep, is not necessary. Since the circuit in the signal generator is electronic, with no mechanical device to produce phase lag, it was possible to use the 6.3 -volt 60- cycle test voltage, right at the front of /View of the sweep the oscilloscope, for the horizontal generator, showing sweep required for viewing the band - added components. pass response curve of the equipment under test. In this case, only a few degrees phase shift of the sweep pat- tern on the oscilloscope was noted. Very good results were obtained with- out lengthy experimenting or "playing around." Approximately half the ac voltage provided well over 300 -kc swing, with the 10.7 -mc point at the top of the band. A 7.5 -volt C- battery, with taps every 1.5 volts, is ideal for provid- ing bias voltage for any required amount of frequency swing. This cir- cuit will work equally well at 4.5 mc, TV sound channel, or even the broad- cast band, where a relatively small (10 -kc) frequency shift is needed. Other values of voltage -variable capaci- tors are available to provide practically any frequency sweep, provided the cir- cuit Q is not brought down so low as to stop oscillation. (The Varicap must be reverse- biased for correct operation. Forward bias may damage it, so check the manufac- turer's instruction sheet carefully for the markings corresponding to the posi- tive and negative ends. Also, the sum of the bias and peak signal voltages should not exceed the maximum operat- CI ing voltage. Set the bias high enough so SHORTED TURN the signal cannot swing the diode into the conducting region. Editor) END Rear of generator (an old Philco). NOVEMBER, 1960 59

www.americanradiohistory.com servicing 1,`..---.._ DISTRIBUTION SYSTEMS

Part I -TV distribution systems are becoming more common in motels, hotels and apartment houses.

By JACK BEEVER * usually by a factor between 20 and large losses "seen" in it. Unlike power 1,000 times depending on the ratio be- or speaker wiring, we cannot ignore TELEVISION distribution systems tween the antenna signals and those these losses. Indeed, the amplifier's cannot be successfully serviced un- required to drive the system properly. major function is to overcome these less their workings are understood. This calls for amplifiers of between 26- losses. In the commonly used RG -59/U The "why" and "how" are essen- and 60 -db gain. type coax, the losses at channel 13 will tial before difficulties can be intelli- From the amplifier on, we have a be around 6 db per 100 feet (see table) ; gently treated. For this reason, it is branched cable system to cover the in other words, the voltage will be down best to examine first the general re- various points where TV sets will be to one half at the end of a 100 -foot run. quirements of TV distribution systems. located. At these points, tapoffs are in- The next 100 feet will reduce it to one - In terms of the job to be done, we serted into the line to allow the set to fourth, the next to one -eighth and so on. must feed number be connected to the line without causing a of television re- Decibels ceivers (from 5 to perhaps 2,000) with undue disturbance in the line or to other signals from a single receiving site or sets on the line. The splitters are de- System calculations are always car- perhaps a single antenna. The signals vices designed to divide the energy in ried out in terms of voltage (since the at each set, to quote the usual specifica- the input cable between two (or more) system impedance is fixed) and db for tions, must be "equal or superior to output cables and to maintain the im- convenience. those found on a single set fed from a pedance match in all directions. The db is not as puzzling as it would single antenna in the same location." The ends of the lines are terminated first appear. It is an expression of ratio The systems are similar to PA sys- in resistors of the same value as the rather than a multiplying factor. In tems, but are immensely different in characteristic impedance of the cable, other words, an increase in voltage of detail and in design technique. This is 75 ohms. These are usually mounted in six db means the voltage has doubled. because of the great difference in the special fittings to provide the smallest Now this boils down to the fact that frequencies handled. The highest audio possible reactive component. when we say 6 db, we mean that we frequencies in public- address work Basically then, we have a system are talking about something which is rarely exceed 15,000 cycles, but the TV which consists of a signal source (the twice as great as 0 db, since 0 db is 1 distribution systems handle from 54 to antenna, an amplifier or amplifiers) times and 6 db is two times. The ques- 216 megacycles (216,000 kc). Fig. 1 and a distribution system whose most tion always comes, "What's 0 db ?" The is a block diagram of a basic system important characteristic is the very answer is 0 db is anything you choose drawn with typical symbols used in the to make it! In TV systems you can trade. specify whatever you like as 0 db. It //// can be the antenna signal, or you can Components choose (as we at Jerrold do) 1,000 µv The components are: an antenna (it read across an impedance of 75 ohms. may be a group of cut -to- channel PWR LINE AMPL The great advantage of using db is that you can and numbers in Yagis) ; an amplifier; line splitters; add subtract tap -offs to connect television sets to the db when computing a system, and the system; terminating resistors to termi- numbers stay small. Otherwise you'd nate the lines in their characteristic impedance, and connecting cables. In any system worthy of the name, coaxial cable is used for interconnecting the various components. The cables are standardized to types having charac- O O 0 © 0 I I teristic impedances of 75 ohms. The more commonly used types are RG -59/U 0 0 0 0 0 I I 0 . `4. and RG -11 /U (or their polyfoam- 0 0 0 O- / O O dielectric equivalents). TAP-OFFS First, we have an antenna delivering ® ® O signals to an amplifier. The amplifier O/ raises these signals to a higher level, ® ® O O O O Fig. 1 -Block dia- gram a Applications engineer. Jerrold Electronics /W MnM NWM NvVN MOW ,-"MAM of typical Corp. TERMINATING RESISTORS building system. 60 RADIO -ELECTRONICS

www.americanradiohistory.com have to divide or multiply at each step, and your computations would involve large, complex numbers. Here are some examples (in terms of voltage) : Gdb =2x 10db =3.14x 12db = 4x 18db =8x 20 db = lO x 30db =31.4x 40 db = 100 x 60 db = 1,000 x Let's take a more practical example. A particular antenna delivers a 1,000 - microvolt signal on channel 7. The channel 4 signal is 6 db higher or 2,000 microvolts (approximately). The signal on channel 2 is 4,000 microvolts, 12 db higher than the channel 7 signal and 6 db higher than the channel 4 signal. Broad -band preamplifier (Jerrold ABD -1). System types Distribution systems are generally either of two types requiring slightly CABLE ATTENUATION DATA /CHANNEL*

I 2 3 1 i CHANNEL 4 6 6 7 B 9 10 11 12 I 13 CABLE CABLE ATTENUATION db/per 100' at pia carrier freq.

RG-59 U 2 8 3.0 3.2 3.4 3.6 5.3 5.4 5.5 5.6 5.1 5.8 5.9

RG-6 U 2.1 2.2 2.3 2.4 2.6 4.0 4.05 4.10 4.15 4.20 4.25 ' 4,3

RG-11 /U 1.6 1.7 1.8 1.9 2.0 2.7 2.75 2.80 2.85 2.90 2.95 3.0

RG-35 U 0.52 0.55 0.58 0.62 0.65 1.10 1.15 1.20 1.25 1.30 1.35 1.4 *Maximum attenuation. different service techniques -the broad - band and the strip -amplifier type. The broad -band uses a single amplifier which is capable of accepting and am- Broad -band plifying all (or any) TV channels. Such ana .lifìer amplifiers are usually a dual amplifier (Jerrold 2300). with a common power supply on a single chassis. One amplifier handles the low -band channels (2 to 6) and the ///

BROADBAND BROADBAND TO SYSTEM PREAMP (FOR AMPL WEAK SIGS) Fig. 2 -Head end of broad -band system. other the high -band channels (7 -13). The strip -amplifier type uses a single narrow -band amplifier for each channel. In general, strip type amplifiers are used to avoid the necessity of reampli- fying the signals when high levels are required and broad -bands are used where output requirements are less evere. Components The most complex component of a system is the amplifier portion, usually referred to as the head end. A typical broad -band head end is block -dia- grammed in Fig. 2. A strip -amplifier head end is more complex, but provides higher output levels and greater ease of control. Fig. 3 is a block diagram of a four -channel Strip type head end for 7 channels of TV and 1 FM. Jerrold

NOVEMBER, 1960 61

www.americanradiohistory.com head end of this type. Strip amplifiers COAX CABLE are available with automatic gain con- trol. Preamplifiers, especially designed COMPENSATING INDUCTANCE for a low noise figure, are used in con- O O MICROWAVE junction with such amplifiers where BLOCKING CAP -ISOLATING CAP signal levels are too low to drive the CAPACITIVE strips to the rated output. TAP -OFF UNIT

SET TRANSISTORS CHAN 3 CHAN 6 CHAN 10 ' CHAN 12 a

SINGLE-CHAN O PREAMPS (USED ISOLATING RES WHEN NEEDED) O O BLOCKING CAP BLOCKING CAP

SINGLE-CHAN RESISTIVE STRIP AMPLS TAP -OFF UNIT TO SET b TO SYSTEM IOVALUES DEPEND UPON SIG LEVEL IN CABLE Fig. 3 -Head end of strip type stystem. Fig. 4- Tapoffs, capacitive (a) and re- Coaxial line splitters are made in two sistive (b). general types -reactive and resistive. Reactive splitters are transformerlike devices and have the lowest splitting losses -2 -way splitters showing a little over 3 -db loss per leg (not really loss, the input power is divided in two halves) and four -way reactive splitters OYTtfT show 6 to 7 -db loss per leg. Special JgjRRCiLDsLtcrxoxIcs CORP types having nonsymmetrical splits are * PN/ P. U.S.A. made but they are not commonly used in building systems. Resistive splitters T WO ways to use transistors at micro- show higher losses: 6 db per leg for wave frequencies have been an- two -way and 12 splitters db per leg for mode was discovered a few four -way splitters, but they have the nounced. One ago by V. W. Vodicka of Len - advantage of improving system im- months pedance matching. kurt Electric Co., San Carlos, Calif. 2N502 with a Tapoffs He found that a Philco are used to extract a small -mc frequency operated amount of 700 maximum rf energy from the coax and up to 2,500 mc. Further tests showed feed it to a television receiver. They lcrro7d that other available transistors that must therefore have -a resistance or im- Two -way coaxial line splitter. have heavily doped bases produce sim- pedance in the tap line. The energy taken from the ilar results. line must be kept small The the -than- so that the tap (and the connected and the capacitive tap (Fig. 4 -a). These cause of greater set frequency range is not com- to it) will not disturb the line imped- taps have two important characteris- expected ance to an extent that will cause reflec- tics: a loss from the line to the receiver, pletely understood, but Vodicka says tions and ghosts. Two types are in called isolation loss, and a loss in the line it appears to have characteristics that combine tunneling and avalanche effects. common use -the resistive (Fig. 4 -b) itself, called feedthrough or insertion loss. The general rule is that the less Under the right circuit conditions, isolation loss in the tap, the more feed - transistor bandwidth is radically in- through loss. creased while noise is reduced greatly. The two types have different char- Already noise figures approach those acteristics, resistive taps showing the of parametric amplifiers. same isolation loss at all frequencies, Another approach toward microwave but causing more line disturbance than transistors is used at Bell Labs. They capacitive taps. Capacitive taps show start off with a mesa transistor whose greater isolation at the low channels (2 total active area is smaller than the to 6) and less at the high channels ( 7 cross section of a human hair. It is a to 13). This tends to offset the loss p -n -p unit that has a diffused base and characteristic of coaxial cables, less loss an alloyed emitter. It is designed for at the low channels and more loss at use as an oscillator at frequencies up the high channels. to 3 kmc or as an amplifier up to 1 kmc. Terminating resistors will be found The mesa section is only 1.8 mils long at the end of all coaxial lines. These and 1.5 mils wide. Three metal stripes, are usually designed into the modified each 0.3 mil wide and 1.5 mils long, body of a coaxial -cable connector with are evaporated onto the surface and the resistor mounted coaxially. It is alloyed into the three parts of the difficult to connect a resistor to the end device. Gold wire, 0.2 mil in diameter, of a coaxial cable in such a manner that is used for the connections. The tran- it will not show inductive or capacitive sistor's diffused base is only 1/50 mil behavior at vhf, so this is no place to thick. look for economies. The unit is built into a coaxial shell Part II of this series will discuss (see diagram) that prevents parasitic some of the symptoms (and their capacitance and inductance. The shell causes) that appear in a distribution itself has an impedance equal to that Single -channel preamplitier (Jerrold system when something throws it out of a 50 -ohm line and is connected to the 406 -A). of kilter. TO BE CONTINUED transistor's emitter. END 62 RADIO -ELECTRONICS

www.americanradiohistory.com WHAT'S NEW

TV DEMONSTRATOR is de- PARAMETRIC TRANSIS- signed to teach basic principles TOR has been developed for use of electronics from fundamental in a Vodicka circuit for ultra- electronic circuits through tele- high and microwave frequencies. vision. It consists of a 3 x 5 -foot A Hughes transistor has been breadboard, 17 -inch picture tube, modified to favor this mode of speaker, and test instruments. operation. The transistor is a The unit is assembled and studied 3- terminal package in which in- circuit by circuit in the class. put and output are easily sepa- Completely assembled, it be- rated. Also, the unit oscillates comes an operating TV receiver and delivers its own pump power. superimposed on a large circuit The pointer indicates the tran- diagram. The unit is made by sistor mounted in a develop- Transvision. mental circuit.

INDUCTORS FOR PRINTED CIRCUITS an- nounced by Corning Electronic Components have wire leads for printed- circuit board mounting. The new units, 26 models, are claimed to have superior stability under physical shock, vibration and temperature changes.

MINIATURE MEMORY DRUM weighs only 6 ounces yet can store 100,000 bits of information. Data are recorded on the magnetic surface of the stainless steel drum (not shown). Measuring 3 inches long and 3 inches in diameter, the IBM unit is designed for airborne computers. NOVEMBER, 1960 63

www.americanradiohistory.com point (at least 50 volts peak to peak), you can suspect the picture tube. You can also go through the video amplifier circuits (with a bit more trouble), if you have one of those adapters that brings the tube elements out at the sides for testing. Check the signal at the video amplifier grid and plate to see if you've enough gain. Same thing with sync tubes: this is IIIIIk E- ilIIIIk most useful on some of the vertical chassis sets which are a bit difficult to get out of the cabinet. Incidentally, for all these jobs, use a IIIIIIIIII = _ = 7IIIIF calibrated low- capacitance probe of the - type used for signal- tracing in video circuits. The probe must be matched to conducted by the scope's input impedance and com- JACK DARR pensated for best results. With the right probe, you can get nice sharp sync THERE are many more uses for the If the pulses are there but pretty pulses (Fig. 4) and clean video. The oscilloscope than hunting distortion small (you'll have to experiment a wrong probe can throw you quite a in complex waveforms, measuring little to get an idea of about how high curve, unless you know its limitations. peak -to -peak voltages, and the other they should be with the scope gain set So, there you are. You can get some "regular" jobs. When used right, it can at a certain place, etc.), the horizontal kind of indication in any ac- carrying be a very useful timesaver in locating output tube's probably weak, again. circuit by just holding the probe close the source of TV troubles. Waveforms at the horizontal- output to it (higher -voltage circuits) or by For instance; no high voltage, screen tube plate, but only a very small pip direct contact (lower- voltage circuits). dark, horizontal output tube not running when you hold the probe close to the red. Where's the trouble? Grab the high -voltage lead indicates a weak or Inadvisable conversion scope and very carefully place the probe defective high -voltage rectifier tube. I have an RCA KCS -82D TV chassis close to but not touching the horizontal Ought to get pretty good sized pips which I would like to convert to use the output tube's plate. See any pulses? anywhere close to this lead ( Fig. 2) . 110° 23CP4A picture tube. Would you (Should look something like Fig. 1). Damper trouble? Hold the scope probe kindly advise me as to what changes I If they're not there, you can begin close to the damper tube from the top would have to make to do this ? -J. A., looking in the horizontal oscillator stage. of the chassis. If you've got high volt- Sacramento, Calif. There doesn't seem to be any drive at age on it, it ought to show up. You I'm afraid that your KCS -82 chassis all and the output tube is probably so should have a pattern something like would require a rather extensive work- weak it won't draw enough current for Fig. 3. ing over to use the 23CP4. Although the plate to overheat! Be sure to keep the probe tip far this tube is listed as a nominal 110° enough away from exposed points like type, the actual deflection angle is the 1B3 plate, the horizontal output nearer to 114 °, thus requiring a tre- tube plate and so on. If you'll practice mendous amount of sweep power. with this a little, you'll find that you You see, to alter the sweep circuits can tell pretty quickly just about what's of a TV set, you must provide not only wrong in or around the flyback circuits more deflection but the large amount by just holding the probe close to them of extra power needed in the deflection in the right places. It will give you an circuits. You have a 70° yoke and de- idea of what's going on and, most flection system in your present set. If important, it'll tell you whether the you changed the yoke to a 90', for ex- horizontal oscillator is working or not. ample, you would get a full 90° scan Signal circuits can be checked the only if you increased the power input same way. Got a weak picture with no to the yoke. Changing only the yoke contrast? Might be a bad picture tube, would result in scanning the tube only age trouble, bad video amplifier tube, partly; you'd find about an inch or so video if trouble or tuner trouble. Pull not covered at top, bottom and sides. the socket slightly loose on the base of On a 70° to 90° conversion, this can Fig. 1-Pulses are found near plate of the picture tube and check at the grid sometimes be overcome by adjusting horizontal output tube. Bring scope (or cathode, whichever the signal is fed height and vertical linearity, width and probe near but not touching plate. to). If you get a nice fat signal at this

Fig. 2 -Scope probe near high- voltage Fig. 3 -Near the Fig. 4 -Sharp sync pulses lead to CRT should produce pips some- damper tube these pulses obtained by using a what like these. should be found. calibrated low- capacitance probe. 64 RADIO-ELECTRONICS

www.americanradiohistory.com horizontal linearity, increasing hori- at 27.25 mc. Remember, all these traps only the length of the elements but zontal drive and substituting "hotter" are tuned for minimum response. You their spacing from each other deter- tube types -for example, a 6DQ6 for may have to crank up the signal gen- mine the wavelength for which the 6BQ6 replacing 5U4's with special sili- erator gain to see the results, but antenna is built. For instance, the con rectifiers. This would demand new always tune for the lowest possible sketch (Fig. 6) shows a channel -4 Yagi filter capacitors, of course, as the in- amplitude at the trap frequency. with eight elements. The most popular crease in voltage might exceed the safe The next trap will be in the second spacing for this type seems to be that ratings of the originals. video if plate and should be tuned to shown: 0.1- wavelength spacing for di- You might check up on such tube 19.75 mc. You may find cathode traps rectors, and 0.15- wavelength for the types as the 24AEP4, which is a 90° in this set; they were used in several reflector. tube with a much lower high- voltage models. If you have a fourth v deo if, To make this antenna work or an- requirement. There are several tubes look for a trap in its cathode circuit. other channel, you should cut the ele- in that group which could be used with This is tuned to the sound frequency, ments for that channel and also change the changes listed. 21.25 mc. their spacing. You may find that the video if adjust- I do not believe you will gain any- Out -of -tune traps ments are on the chassis between the thing by trying to use more than a total We have a Freed- Eisemann set with tubes. Be sure to check the circuit con- of eight elements: reflector, dipole and the traps out of tune. I cannot find any nections carefully. Your traps will six directors. At this point in Yagi information on this particular model always be "coupled" while the f coils design, you have the maximum ,rain. anywhere. The only diagram I can find themselves will always be in series with Addition of more directors wil'_ erve has one less tube than this one. This is the plate circuits! to narrow the frontal lobe slightly. but a model 1916 and has one more 6AU6 Here are the most likely alignment will give you only an imperceptible than the one in the diagram. Can you frequencies for the video if's Con- amount of additional gain. Besides verter (in tuner) 21.8 mc; first video if this, the antenna will get so long that 50% plate, 25.3 mc; second if plate, 22.3 mc; it will to most unwieldy to handle: third if plate 25.2 mc, and fourth if plate, 22.4 mc. Hum in Crosley As to the exact procedure: With the A Crosley 11-459MU has a sr vere equipment set up to produce the video hum. How can we get rid of it?-W. M., 27.25 25.75 21.25 19.75 if curve, remove the short from one Westville, N. J. PIX FREQ-MC SOUND a trap at a time and move the adjust- This set has a full -wave rectifier and ment slug. See which section of the power transformer. If the hum is 120 - curve is most affected (by means of the cycle (two bars on screen) it's a weak markers.) For instance, if the left or open filter capacitor in the power (picture) side of the curve is most supply. If the hum is 60 -cycle (one bar affected, the trap is probably the 27.25- on screen) , it's heatercathode leakage mc trap. the side of the curve 27.25 25.75 21.25 19.75 If right in some tube in the signal channel. PIX SOUND TRAP is moved most, this is likely to be TRAP FREQ-MC trap TRAP the 21.25 mc sound or adjacent -channel Remote uncontrol pix trap, and so on. We had a Zenith 16C21Q, with Sauce Fig. 5 if response curves; -Video a- Command automatic tuner play;nu on some sound signal getting through; b- Build -it- yourself Yagi sound trap adjusted for minimum sound the bench the other day after rejairs signal. I would like to obtain the plane for a to the if ship. Suddenly, the se' tu.ned 10- or 16- element Yagi antenna. with itself off. Later on, the tuner (acted give me this information ? -W. H., the shortest boom, to work on channel 4. the volume lip Astoria, N. Y. running and went and If I want to operate it on another chan- down although the control box was not I'm sorry, but I couldn't find any nel, would only the length of the ele- being used. We have checked the con- model service data on this exact either. ments need to be changed ? -D. F., trol unit in the set several times. Ap- However, there are some generaliza- Kingston 11, Jamaica, B. W. I. parently not a thing is wrong with it tions on trap tuning that should help To be a true Yagi configuration, not of a. nature which could cause this irter- you. nrittent false triggering. Do yon have I'm going to In the first place, assume any ideas as to the cause of thi3 ?- that this is a split -sound circuit, from f 90" J. D. Q., Big Cedar, Okla. the age of the set. These sets often had I The same happened more traps than the others: adjacent - 25.201.15)) sure do! thing channel picture, adjacent- channel sound to me not too long ago! Evidently, there and sound if are standard. However, -11 were other sets in operation on the same these can be tuned up if you have bench, and probably close to the micro- sweep- alignment equipment. phone of the Space- Çommand receiver. Set up the equipment and TV set to If another TV set is operating close by display the video if response curve on 77" and the horizontal oscillator is turned the scope. I am assuming that the set off frequency (not necessarily enough CHAN 4 to cause the flyback to "sing" audibly) uses a 21 -mc if from its age. It might YAGI be a good idea to "strap" the traps all enough to generate a harmonic in the out at this time to avoid troubles due to range of the Space -Command receiver, their misalignment. Simply tack a short the control unit will "fire!" The oper- piece of wire across each one. This takes ating signals of the control unit are in it out of the circuit. Set the picture and the supersonic range, around 30-40 kc. sound carriers as shown on the curve What is happening here is this: The 17.2"(1710 ))' of Fig. 5 -a. horizontal oscillator of the other TV With this done, find the first trap. set is generating harmonics and causing This should be the sound trap and will the flyback or some other part to probably be located in the tuner, in or radiate an actual audio signal. Some- near the converter output transformer. where in this mess of frequencies, there This is tuned for a minimum amplitude is a harmonic that is exactly on fre- on the curve at the sound frequency quency to operate the tuner or volume (Fig. 5 -b) . control. This is more apt to happen if The next trap will be in the plate AO" the other horizontal oscillator is quite circuit of the first video if and will be Fig. 6.. Sketch of Yagi antenna with a way off frequency. You can even make the adjacent -channel sound; this is set elements cut for Channel 4. (Continued on page 70) NOVEMBER, 1960 65

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www.americanradiohistory.com (Continued from page 65) oscillator transformer. If you can get a the controller do this by turning the floating picture (floating from side to PRODUCTS Zenith's own horizontal oscillator quite side, but obviously a complete picture FOR a way off the correct operating fre- horizontally), then the trouble must quency. Under normal circumstances, lie in the phase-comparer circuit. MODERN in the home, it never happens. We Replace these with a Federal K -1616. checked for this! This is the unit with both diodes "look- LIVING ing the same way." Be sure to install it Pulling so that the polarity is the same as in PLUG -IN TYPE me PORTABLE A Raytheon model C- 2111A, has the original. It would also be wise to puzzled. When the contrast is fully ad- make resistance checks of all resistors INVERTERS* vanced, the top of only the picture pulls in the phase -comparer output circuit MODELS to the left, n.ot the raster. and a scope check for the presence of A.C. HOUSEHOLD ELECTRICITY 6 -RMF (6 volts) 60 to 80 A scope on the plate of the 6AH6 Anywhere ... in your own cod watts. Shipping weight 12 the comparison pulse from the flyback Operates Standard A.C. lbs. DEALER NET shows (at low contrast levels) that the (also of a horizontal sync pulse). Record Players PRICE 533.00 Dictating Machines 12T -RME (12 volts) 90 to sync pulses are there As the contrast Small Radios 125 watts. Shipping weight "Ringing ?" Electric Shavers 12 lbs. DEALER NET control is advanced, a straight horizon- Heating Pads, etc. PRICE. . $33.00 tal line colites up and "chokes" out the A Sylvania I -523 TV chassis in the In your own car or boat! *Additional Models Available pulses There is also a loud hum in the shop has bright vertical lines (ringing). sound. -E.J. S., St. Louis, Mo. I've checked the components in the yoke "A" Battery Your observation is correct: the and horizontal circuit, changed the horizontal line you saw in the scope yoke, changed component values, re- ELIMINATOR pattern is the basic cause of the trouble. placed the 6CD6 with a 6DN6 and ion For Demonstrating and trap, installed a grid -drive variable Testing Auto Radios - This could be the sync tips and you TRANSISTOR or VIBRATOR are obviously getting a severe overload capacitor and tried several other sub- OPERATED! stitutions to no avail. All voltages are Designed for testing D.C. somewhere in the video circuits. Electrical Apparatus on Reg- normal; yoke and flyback are the origi- ular A.C. Lines -Equipped Carefully check all components in the with Full -Wave Dry Disc - nal.-W. N. S., Sarnia, Ontario. Type Rectifier, assuring video plate circuit, with special atten- noiseless, interference -free From the lack of response to your operation and extreme long tion to the series -peaking and shunt - hfe and reliability. peaking coils (Fig. 7). This type of cures for yoke ringing, I think your MAY ALSO BE USED AS A BATTERY CHARGER trouble lies elsewhere. You know, some- MODEL 610C -ELIF ... 6 volts at 10 amps. or 12 volts choke, with a resistor in parallel, can at 6 amps. Shipping weight 22 lbs. times a negative result to a test is as DEALER NET PRICE 549.95 6AH6 270 H MODEL 620C -ELIT ... 6 volts at 20 amps. or 12 volts at VIDEO OUTPUT TO CRT valuable as a positive one! There are 10 amps. Shipping weight 33 lbs. TO SOUND CATH DEALER NET PRICE $66.95 some other possibilities such as a dis- IFAMPµf torted waveform being fed to the grid AUTO -RADIO 220 K 2 of the horizontal output tube, although FROMM I 305µH 100K 150y judging by the thoroughness of your VIDEO VIBRATORS .005 DET = BRIGHTNESS testing, it is very likely you have By every test ATR Auto - 470 K Radio Vibrators are best! 5.6K already covered that possibility. Any and feature Ceramic Stack Spacers, Instant Start. _ 10 tiny traces of ringing here would, of ing, Large Oversized Tungsten 68tí 270µH Contacts, Perforated Reed, course, be amplified by the output stage. plus Highest Precision Con- me, struction and Workmanship and The most likely cause, it seems to Quiet Operation! 2.5K CONTRAST 235V would be video pickup of radiated There is an ATR VIBRATOR for every make of ear! 150 V energy from the horizontal circuits. Ask your distributor for ATR's Low Priced type 1400, 6 volt 4 -prong Vibrator; and 1843, 12 volt 3- prong; or Fig. 7 -Video amplifier of Raytheon Check the appearance of the raster 1840, 12 Vibrator. THE WORLD'S FINEST! volt 4 -prong C- 2111A. without signal. If the scanning lines There is a trim plate curve where the lines are showing up, kit for YOUR CAR! CUSTOMIZED cause trouble if it opens, leaving the resistor to provide the plate loading. then it is yoke ringing (Fig. 8). If KARADIO If everything checks out (including they are straight but vary in intensity, Vibrator -Operated - then the trouble is due to horizontal with Tone Control the 6AH6), go back to the 6BE6 sync ATR KARADIO ... is clipper stage and check the operating pickup in rf, video if, detector, etc. ideal for small import cars or compact voltages very carefully. Your pulling stages. This is usually due to radiation American cars! Unit from the yoke connecting leads. Wrap is completely self- contained -extremely compact! Pow- is obviously sync trouble as it doesn't erful 8 -tube performance provides remarkable freedom them in metal foil and ground both ends from engine, static, and road noises. The ATR affect the raster. It could be caused by Customized Karadio comes complete with speaker and an unbalance somewhere in the sync of the foil by wrapping a bare wire ready to install. Can be mounted in -dash or under -dash -wherever space permits! No polarity problem. Neutral clipper or its circuitry. Check the set- around the foil and grounding it under Gray -Tan, baked enamel finish. Overall size, 7" deep. 4" high, and 61/2" wide. Shipping weight, radio set, 7 lbs. ting on the agc switch (marked AREA a nearby screw. Dress the lead -in cable, Model K- 1279 -12 for 12V Dealer Net Price. . 533.57 from antenna terminals to tuner, along Model K-1279- 6 for 6V Dealer Net Price. . 533.57 SELECTOR). If you're in a strong -signal location and it's set for fringe opera- the side of the chassis or as far away Airplane Style Overhead Mounting Cab Roof NO PRINTED from the yoke leads as possible. END under CIRCUITRY tion, you'll get normal overloading from excessive agc. /RINGING KINKS TRUCK Drifting sync be wrong with a Trav -Ler KARADIO What can RASTER Excellent Tone. portable, chassis 729 -17A that goes for LINES Volume. and Sensitivity! a few minutes perfectly and then falls Compact, yet powerful. Fits all trucks. station wagons, out of sync. If it is turned off and 1. most cars and boats. Just drill a Ve inch hole in roof and -/ suspend the one -piece unit (aerial, chassis and speaker) allowed to "rest" for a few minutes, it rR in minutes. Watertight mounting assembly holds anten- na upright. Yoke -type bracket lets you tilt radio to goes OK, then falls out again. Tubes INTENSITY VA RIATION S any angle. Extra- sensitive radio has 6 tubes (2 double -purpose). have been changed with no results. over -size Alnico 5 PM speaker for full, rich tone. Big, easy -to-read illuminated dial. Fingertip tuning control. Using the horizontal hold to straighten Volume and tone controls. 33 -in. stainless steel antenna. the picture is no use because turning RASTER Neutral gray -tan enameled metal cabinet, 7 x 611 x 4 in. high over -all. Shipping weight 101/2 lbs. it left or right won't correct defect. LINES TR- for 12V Dealer Net Price - Model 1279 -12A $41.96 Model TR -1279- 6A for 6V Dealer Net Price 541.96 A. D. C., West Orange, N. J. SEE YOUR ELECTRONIC PARTS DISTRIBUTOR This trouble seems to be in the hori- WRITE FACTORY FOR FREE LITERATURE... é zontal phase -comparer diodes from the Fig. 8 -(a) In true yoke ringing, raster AMERICAN TELEVISION L RADIO CO. description. Shunt horizontal oscillator lines bend. (b) When video stage picks aTiR 20444, Psa aeeta Seau /937 input grid to ground, then run a com- up horizontal radiation, they vary in SAINT PAUL 1, MINNESOTA -U.S.A. plete realignment on the horizontal intensity.

70 RADIO -ELECTRONICS

www.americanradiohistory.com HORN DRIVER jptoing PA systenis University Loudspeakers, Inc. Outdoor PA speaker. Different power drivers are available as well as different - size horns. A simple series capacitor can improve the intelligibility of a PA system

By LEO G. SANDS system can be /16 feed line is used, a 02 -pf paper capac- PUBLIC -ADDRESS +1: mil+ by simply itor may be connected in series with the made to sound better FROM AMPL connecting a capacitor in series line (Fig. 1 -b). with each loudspeaker (or the a I6ß SPKR Fig. 2 shows capacitor values for various low- frequency cutoff points for speaker feed line). Power requirements LINE TRANS are cut and power -handling capacity a. If different impedances. Find the correct FROM .2 2II level line by referring to the first and can be doubled. 5O0ß LINE In voice reinforcement systems, there second columns of the table. Next, select is no need for overheating speaker voice b a horn cutoff frequency from the scale coils with unheard audio power. For Fig. 1 -a -An 8 -pf (two 16 -uf electro- at the left of the chart and find where series) in series with maximum speech intelligibility, low -fre- lytics in capacitor it intersects with the level line. From a loudspeaker keeps unwanted low fre- quency response can be cut off anywhere this point, go downwards to the bot- quencies out of voice coil; h -a capaci- tom scale. This will give you the capac- between 200 and 600 cycles. tor ivav be used in similar fashion in a Horn type speakers which cut off at, line. itor value (in µf) when multiplied by speaker feed in say, 300 cycles will continue to con- the proper factor which is found the sume power at frequencies below 300 third column of the table. In fact, MULTIPLY cycles but for no good purpose. IMP LINE Loudspeakers most of the available amplifier power (.n) BY The is the most critical part is wasted on unwanted (and unheard) 4 B 00 speaker low-frequency signals. 8 G 00 of a PA system. For indoor use, cone 16 H 00 type speakers are often used because By connecting an 8 -µf capacitor in K 32 0 is no need for a weatherproof series with the voice coil of a 16 -ohm 45 J 0 there speaker, the power -handling capacity of 100 C 0 speaker. However, most cone speakers 125 F 0 are extremely inefficient (1% Tx ) the speaker is doubled. Low -frequency 165 H 0 (Continued on page 74) response is cut off at approximately 250 E 400 cycles. Since an 8 -µf paper or oil - 500 D 1000 C 2 values for two Fig. -Chart gives series -capacitor filled capacitor is expensive, the 2000 A . different impedances and frequencies. rections of a dual 16 -µf electrolytic 5000 D . University Loudspeakers, Inc. capacitor (or two independent 16 -i f IKC MO IEMMMI-i/-/IAMIÌ /IMII/14. electrolytic capacitors) can be con- MN= MIEN1==%//ANIPAMIIMM nected in series opposing as shown in NM= IIMIEIII/II//%MIdJI.%/-%I.'%N Fig. 1 -a. I I iiii.I.gi At 400 cycles, current flow through M '/. the voice coil is cut 4 to 1 (12 db) ; = 1/%I %%///I% at 1,250 cycles, voice -coil current is halved (6 db) ; at 3,000 cycles, the at- I. tenuation is barely noticeable to the /. ear (3 db) and at 5,000 cycles, attenu- Iurddr4IIu ation is only 2 db. At 10,000 cycles, the I r 111 loss imposed by the capacitor is less I//ii than 1 db. 100 1 %,.alp© II For an 8 -ohm speaker, a 16 -µf capac- IIIiMIWIIIII IIIIIIIMMIIIII 60 II//II.//.%//I in itor is used (two 32 -µf electrolytics .5 1 ..03 series) and when a 500 -ohm speaker CAPACITANCE INµf NOVEMBER, 1960 71

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www.americanradiohistory.com (Continued front page 71) whereas horn type speakers are much more efficient, some running as high as 50 %. If a cone speaker has an efficiency of only 1c/c, it requires 10 watts of elec- trical power to get 100 mw (0.1 watt) of acoustic power. A 50% efficient horn speaker on the other hand delivers 5 watts (or 50 times as much acoustic power) when driven at 10 watts. The sound from a cone speaker is dis- persed in a 180° pattern, the high fre- quencies being directed forward in a narrow beam and the low frequencies being dispersed over a wide area. Horn speakers are available in various de- signs, some providing wider coverage than others (Fig. 3). A cone speaker

E -C Equipment, Inc. Line transformers for 70-volt systems. Small transformer on left is rated at 5 watts, center one at 50 watts and the one on right at 15. 70 -VOLT we use a ground plane, coaxial or turn- LINE IMPEDANCE WATTS stile antenna. For sound coverage we OHMS PRI 0 COM could use cone speakers but, to avoid power waste, we would use a battery 30 165 of horns arranged to provide 360° hori- 25 200 zontal coverage. 20 250 WIDE-ANGLE HORN Feeding the speakers

15 325 Considerable power can be wasted in SEC o the speaker feed lines. It is feasible to Fig. 3 -Round horn provides greater 10 500 an feed speakers at voice -coil impedance distance and noise penetration, while through 50- to 100 -foot lines with a wide -angle horn provides much broader 80 coverage. 5 1000 separate line to each speaker. If we 6n attempt to feed four paralleled speak- can be likened to a fluorescent lamp cov- 2.5 2000 ers through a single, long line, four ered by a translucent lens whereas a times as much power is wasted in the broad coverage horn is like a floodlight line. (Line losses increase as the square and a narrow beam horn is like a spot- 1.25 4000 of the current and only the first power light (in terms of coverage). of line resistance.) Today, there are many types of .65 800 Commonly, speakers are fed at 250 speakers, enabling to a the installer select OUTPUT SPKR or 500 ohms. Each speaker (or speaker the type (or types) most suited for a VOLTS WATTS SEC group) is fed from a common line or 25 40 particular installation. For speech re- through individual lines. An impedance - inforcement, the speakers have two ob- matching transformer is necessarily jectives: 19.8 25 1- cutting through noise; and PRI used at each speaker location. 2- covering the desired area with 5.7 16 The impedance -matching technique sounds which are pleasant to the ear. 70 -VOLT LINE -012.5 10 has some disadvantages which are over- Cutting through noise requires narrow - come by the constant -voltage technique. beam horns (spotlights) and broader 9.9 6 Instead of worrying about impedance, coverage is obtained with speakers hav- 7.9 4 we can deal with Ohm's law instead. ing wider dispersal patterns (flood- The output of the amplifier is fed at a lights). 6.3 2.5 nominal level of 70 volts to the speaker If we look at speakers as we look at feed line. The speakers look upon the communications and TV antennas, COM 0 it b line as a power line. To them it simply becomes apparent why some speaker means 70 volts ac, not so many ohms. manufacturers Fig. 4- Line -matching transformers: a find it necessary to man- -power level is controlled by choosing (Systems with over 100 watts output ufacture up to 74 speaker combinations different primary taps; b- primary is use 141 -volt lines and there are some 25- to meet all PA- system requirements. connected to 70 -volt line while power is volt distribution systems.) To squirt a vhf radio signal to cover controlled by choosing correct secondary A stepdown transformer is used at a narrow area, we would use a dual tap (wattages given are for 16 -ohm each speaker. The volume level at each Yagi array or some other highly direc- speaker). location is controlled individually by tional antenna. If noise is heavy or the ray. For sound, we would use a folded tap selection. The transformers are cal- distance is great we would increase the horn with the required dispersal pat- ibrated in two ways -impedance and transmitter power or use an even high- tern or a battery of horns. To transmit voltage (Fig. 4). Using the first (Fig. er -gain antenna. In the sound business, in two opposing directions, we could 4 -a), the speaker is connected to the we add more driver units to the trum- specify a figure -8 antenna or connect proper tap on the secondary. One side pet -type horn to send more acoustic two corner reflector antennas back to of the 70 -volt line is connected to the power in the desired direction. back. Similarly for sound, we would use common tap on the primary, the other To cover a fairly wide area straight two horns back to back. side to the appropriate tap (which may ahead, we might use a single Yagi ar- For omnidirectional radio coverage, be marked in impedance or wattage) 74 RADIO -ELECTRONICS

www.americanradiohistory.com how? h T2c43

Consider the new 15" Wolverine full -range speaker -not just bigger - better, too! The larger radiating area of the Wolverine LS15 gives it a performance edge in the bass region. The greater air load of the larger cone lowers the speaker's resonant frequency, allows the, LS15 to radiate more sound power at those hard -to -get bass frequencies. You can see the superior strength and rigidity of the cone of the LS15 that maintains truer rigid -piston motion at bass frequencies, and provides better control of the more complex modes of operation that come into play at higher frequencies. Compare the Wolverine loudspeaker series with any other make. Whether you're interested in the LS8 (8 "), LS12 (12 ") or the LS15 (15 "), you'll find more quality per feature, and more features per dollar, in the remarkable Wolverine components ... by Electro- Voice. You get all these specific quality features. Heavy duty, diecast frames permanently maintain the alignment of the voice coil in the high -precision magnetic gap ... glass coil forms maintain voice coil shape for life ... edgewise - wound voice coil increases efficiency 18% over conventional coils . .. two specialized cones give efficient reproduction of both bass and treble frequencies ... compact design makes them easy to install in today's sound -conditioned homes. When your budget allows, you can get even wider range and better overall listening quality with Wolverine midrange and high- frequency step -up kits, easily added to any of the three basic Wolverine full -range speakers. Add the HF1 first, to bring out the subtle brilliance of modern stereo records, tape, and FM radio. Then, add the MF1, for greater midrange clarity, spread more evenly throughout the room by the famous E -V diffraction principle. If you're shopping for quality and economy, your finest choice is an Electro -Voice Wolverine speaker.

Model LS15 - Specifications - Frequency response 35 to 13,000 cps; EIA sensitivity rating 46 db. Free -space cone resonance 35 -45 cps. Power -handling capacity 20 watts pro- gram, 40 watts peak. Impedance 8 ohms. Mechanical cross- over 4500 cps. 15343 inch diameter, 6%hz inch depth, 13 inch baffle opening: mounts with four holes 'Az inches equally spaced on 14M' inch circle. Net weight 11 pounds. Shipping weight 12 pounds. Net each $24.50. gieerefece.

Dept. 110E, Consumer Products Division ELECTRO-VOICE, INC., BUCHANAN, MICHIGAN

www.americanradiohistory.com for the power level desired. In 25- and 141 -volt systems, required primary im- pedance equals (Output voltage)2 Desired power to speaker The other type of stepdown trans- former has its primary connected to the 70 -volt line. The speaker is connected to SPEAKING OF LINES ... the common terminal and the terminal that will give the desired power level. The taps are marked in terms of volts. Wattage ratings are for 16 -ohm speak- ers. Ohm's law will give the output power available at each tap (Fig. 4 -b). When the amplifier has good output voltage regulation characteristics, we can connect (and disconnect) speakers from the line without significantly af- fecting the level of other speakers on the same line. This is particularly ad- vantageous from the servicing angle. Overall efficiency A 10 -watt amplifier can be made as ... The complete line of Astatic microphones in- effective as a 100 -watter by using more cludes types and styles to meet all communication efficient methods. A 10 and amplification needs. Astatic offers a full range -watt amplifier feeding 331/3% efficient of models ... every one superbly engineered with horn speakers many advanced features found in no other line. There will deliver more than three times as is an Astatic microphone to meet all demands for much sound as a 100 -watt amplifier finest fidelity . . . to resist wear and tear of the feeding a like number of 1% efficient most abusive service, extremes of temperature and cone speakers. the elements ... to fill the bill whatever is required. Power waste can be reduced by using This is why Astatic microphones are preferred by more efficient line -matching transform- sound engineers and installers the world over. Astatic ers. If we feed 10 speakers through 10 has been manufacturing quality microphones for line transformers of 80% efficiency in more than a quarter century and none which ... a 100 -watt we be carries the Ascetic label is ever unworthy of the system, will wasting name. Illustrated are a few popular Astatic models. 20 watts in the transformers. If 95'yo efficiency transformers are used, only Model 77- highest fidelity with most positive anti - 5 watts will be wasted. feedback characteristics of any cardioid. By selecting the right speaker (or Vogue 988 -utmost professional instrument quality. speaker combinations) for a specific THREE -THIRTY application, we can use less power for Three- Thirty Series - small, compact, classically SERIES simple in design with professional performance. a given sound level and put the sound where we want it. When directional Model DN-50--famous for performance with famous loudspeakers are used, the correct illu- traditional microphone design. sion (sound appears to be coming from WORLD'S MOST FAMOUS NAME IN PHONO microphone location) can be preserved CARTRIDGES AND NEEDLES, MICROPHONES and acoustic feedback problems can be minimized. THE But, the biggest jump in efficiency, speaker life and speech reproduction CORPORATION, quality can be made by keeping un- 4101711-1lCMS CONNEAUT, OHIO wanted low frequencies out of speak- ers by adding a series capacitor. END In Canada: Canadian Astatic Limited, Toronto, Ont. Export Sales: Roburn Agencies, Inc., 431 Greenwich St., N. Y. 13, N. Y., U.S.A. [The capacitance tolerance of an elec- trolytic capacitor may vary from -20% to +250% , depending on the type and voltage rating. The actual cutoff fre- quency of the speaker will then vary Over 1000 Sold The 1st Month! Not One Returned To Date! inversely as the capacitance in the cir- cuit. For example, the chart shows that RADIO-TV PARTS a 4 -ohm speaker will cut off at 150 UND cycles with a 90 -µf capacitor in the cir- JUMBO PAKS! cuit. If this unit has a +100% toler- COMPLETE SATISFACTION -MONEY BACK GUARANTEE ance, its actual value is 180 µf and the 16 actual cutoff frequency is 75 cycles. If ONE POUND Precision Resistors Worth $100, NOW $1100 the capacitance is 20% low, the cutoff TONS ONE POUND Disc Condensers Worth $50, NOW per rises to around 190 cycles. pound of mfr's ONE POUND Ceramic Condensers ...... Worth $85, NOW If the size of the capacitor makes it ONE POUND Discs & Ceramics Worth $75, NOW necessary to select an electrolytic, you Over -runs ONE POUND Discs, Ceramics, Precisions Worth $70, NOW can select the unit on a capacitance pre -packed bridge or hand -pick the unit with the to save BUY 4 PAKS for $11.00 e help of using an audio signal generator you money and an output meter. Try capacitors of HOW TO ORDER: Include check or M.O. with sufficient approximately the correct value until FREE GIANT postage; excess returned. C.O.D. orders, 250/ down; you find one that drops the output 6 db BARGAIN CATALOG rated, net 30 days. INCLUDE ICHELSEA t50, MASS. WRITE FOR YOURS! POSTAL ZONE in address. at the desired cutoff frequency. -Ed- itor] 76 RADIO -ELECTRONICS

www.americanradiohistory.com THE TRANSIENT

By DELLROYE D. DARLING NY good technician knows the secret of troubleshooting is the CAPACITOR ability to analyze a circuit and puzzle out how it works. How- ever, most types of electronic equipment have some component parts that always auatd Te 901? seem to be there, yet don't seem essen- tial to the operation of the circuit. A good example is the "fusible resistor" found in most television receivers. The TRANSIENT CAPACITORS circuit will probably work if it were shorted out, and only a TV technician knows how serious it would be to elimi- nate it. The TV- trained man called to service industrial equipment for the first time may be able to figure out how the cir- cuit works, yet the purpose of some items may puzzle him. For example the "transient capac- itor," a ceramic or mica of about .01 µf usually found across the grid cathode socket lugs on thyratron timer tubes, and often on used in other applications, such as power con- trol. The need for this capacitor stems from the fact that the grids of gas - filled tubes have a very different control action than those of vacuum tubes. Most TV technicians know that a thyratron can be held blocked as long as its grid is sufficiently negative. It will suddenly come to full conduction when the nega- tive bias drops below a certain level. But few realize how sharp this "threshold" is. When a thyratron is about to conduct, a change in grid bias of a very small fraction of a volt can push it over the edge into full con- Underchassis of weld -timer, "brain panel," showing transient capacitors. duction. If this small push comes from Robotron Corp., Detaoi:. Mich. an external source such as a transient voltage, the tube may fire sooner than heavy equipment are often connected GRID-ANODE CAP STILL 3-6µ4 to the same lines. When these inductive it should. 360V LI In timer circuits, this transient firing loads are switched on and off, they PEAK IKV 999.?V can cause serious trouble. It may cause large pulses of transient voltage T TRANSIENT shorten a timed interval and upset the across the line. These transients can accuracy of the whole timer. be as high as thousands of volts, and Most thyratron timers operate on 60- may travel hundreds of feet along the 3 -6µµf T oRV cycle ac taken from the plant supply supply lines to upset the operation of thyratron tubes. Although an isolation L2' lines. Theoretically, these lines should GRID- ATHODE always be at their rated voltage, 230, transformer is usually used in the NOW OVER .01 pf TRANSIENT CAPACITOR 460, etc. However, large motors, weld- timer, the transient may be coupled Fig. 2- Transient capacitor upsets volt- ing machines and many other types of almost as well as the supply voltage, age- divider effect -hardly any of transi- and will appear across the cathode ent appears on grid cathode circuit. anode of the tube (Fig. 1). *Director, Industrial Electronics, Radio Elec- 2. tronic Television Schools, Detroit, Mich. Even though the interelectrode capac- voltage divider as shown in Fig. It itances of the tube are small, at the causes practically all of the transient high frequency of the transient they to appear between the grid and anode, GRID-ANODE CAP 3 -6µµf may have enough reactance to form a where it does no harm, since iT only 360V LI PEAK capacitive voltage divider, and -since makes the grid more negative for an IKV T 500 V the cathode grid and anode grid ca- instant. IKV TRANSIENT pacitances are approximately equal -a These capacitors don't fail often. transient that is positive to the anode Still, it does happen. If the transient of the tube can cause the grid to go capacitor shorts, the grid wiïl be tied T 500V positive by half or more of the transient to the cathode, and the trouble will be voltage. this occurs near the obvious. If it opens, the circuit may L2i If start of a positive half -cycle on the anode, appear to work normally, but transients GRID -CATH CAP 3-6µµf the tube will fire for the remainder of on the line will cause an annoying Fig. 1- Internal capacitances of tube that half -cycle, energizing the load. "intermittent" of the sort that occa- forni voltage divider (in dashed lines) When the transient capacitor is added sionally drives good technicians to that may drive grid 500 volts positive. between grid and cathode, it upsets this drink. END NOVEMBER, 1960 79

www.americanradiohistory.com SIMPLE

FM CORERTER

FOR 11r

By JONATHAN VANDERWALL ONE day recently, I wished to listen to a local FM station. Unfortu- nately, the only FM set in the house was not working -the ratio- detector coil was defective. Since it was Sunday, no coil could be obtained and I faced the prospect of missing a good program. However, with a grid -dip oscillator, an intercarrier TV receiver and an old copy of RADIO- ELECTRONICS, a simple but effective converter was devised. Before going further, let me mention that the principle involved here has been "borrowed" from the description of the Regency RC -103 FM Televerter given on page 33 of the April, 1958, issue of RADIO- ELECTRONICS. It is common knowledge that an intercarrier TV set requires not only the sound signal but also an additional signal (usually the picture carrier) exact replacement STANCOR TRANSFORMERS displaced 4.5 mc from it. When these two signals reach the video detector,

, 4 they produce a 4.5 -mc beat signal t h : _ . _ the better which is fed to the sound if amplifier FLYBACKS YOKES POWER TRANSFORMERS and then the ratio detector or quadra- ture detector or what have you. Note Your distributor has them in stock -along with many other that the additional signal need contain and Complete no modulation and, further, that it may types the complete line of Stancor Coils. be either 4.5 mc above or below the replacement listings in PHOTOFACTS and COUNTERFACTS. sound signal. The trick is to use the fundamental CORPORATION and a harmonic from a single oscillator CHICAGO STANDARD TRANSFORMER to do two jobs. The fundamental com- 3501 WEST ADDISON STREET CHICAGO 18, ILLINOIS bines with the given FM signal to produce a difference frequency lying versatile MULTI -PROBE Patent Pending ANOTHER The somewhere in the lower TV band. The DOES THE WORN OF O PROBES! second harmonic of the oscillator must /7//E/W1b21/J lie 4.5 mc away from our difference frequency. We choose the frequency of AC /Ohms Probe Ì DC Probe our local oscillator by using the for - SERVICE AID FM + 4.5 mula: f.- 3 where FM is the Can be used RF Probe with your frequency of the FM station that you VTVM, wish to receive and is the oscillator SCOPE or Model MP -1 $075 Lo -Cap Probe f SIGNAL MULTI -PROBE Net frequency. Both are in megacycles. TRACER / Now for the first time - exclusive with MERCURY - For example, let's say we have an a MULTI -PROBE that does all the work of 4 different FM signal at 92.1 mc. The oscillator A quarter turn of the head probes. Functions: DC position ...matches VTVM in- selects either DC, put impedance AC /Ohms position . for all low Save the frequency, low impedance, voltages and wave forms 92.1+4.5 cost of AC /Ohms, Lo -Cap frequency is: 3 or 32.2 mc. or RF probe RF position .. a demodulator for checking RF volt- 4 separate ages, wave forms and signals and TV /radio RF and IF probes! positions stages Lo- Capacity position . a must for high im- This is then beat against the 92.1 - pedance, TV sync and radio circuits where regular me signal to produce a signal at See your electronics parts distributor probes overload the circuit. 59.9 mc which is in reach of the set's SEARING YORK MERCURY ELECTRONICS CORP., West ófCfice 93 6 W. Victory Blvd., Burbank, ati fine tuning on channel 3. The second

80 RADIO -ELECTRONICS

www.americanradiohistory.com harmonic of the oscillator signal is 64.4 mc, just 4.5 me from our sound - carrying signal. These two signals are fed to the TV set, which does the rest. The simple circuit (see diagram) may be used with a grid -dip oscillator or conventional signal generator. The local oscillator (grid -dip or generator) is coupled by a two -turn link to the "REK -O -KUT "- the safest word you can say to your dealer tuned circuit. The tuned circuit shown For sixteen years, Rek -O -Kut has been synonymous with highest quality in is not critical; I simply set it to res- turntables. As other brands have risen, fallen and even completely- dis- onate at 95 mc. As it is loaded heavily, appeared, Rek -O -Kut has won consistent acclaim as the overwhelming its Q is low. choice in its field. In performance ratings as well as engineering contribu- C -3 to 30 µµf, variable tions to turntable design, Rek-O-Kut has compiled a record unchallenged D -1N82 L1-4-turn 1/4- inch -diameter air -wound coil tapped by any other turntable producer. Now, this tradition is again emphasized at I 'urn, No. 20 wire wound 16 turns per inch by the introduction of the N -3411 STEREOTABLE a (Air -Dux 516T or equivalent) ... professional qual- L2 -2 -turn link ity, two speed (331/3 and 45 rpm) turntable. Quiet power is furnished by a DIPOLE 2 TURNS Rek -O -Kut hysteresis synchronous motor and an efficient new belt -drive ANT / C COUPLED TO OSC 3 -30 system. Speeds can be changed even while is µµt Uri SIG GEN the table rotating, merely by IN82 pressing a lever. L TO TV ANT L2 D TERMINALS 07: TV SET The N-34H is a symphony of crisp, clean lines accentuated by the unusual deck design. Mated with the new tapered base, N -34H Detail of circuit connected to TV; the becomes one of grid -dip oscillator couples to L2, the proudest and most beautiful components ever to grace a home music antenna is cut to FM band. system. See it at your dealer's. Therefore, changing the tuning does N -34H STEREOTABLE only - $79.95 net. Shown with new Rek -O -Kut not make much difference. Micropoise There are two tips about using this Stereo Tonearm, Model S220, $29.95 net. Tapered base in hand, unit which I would like to pass along. rubbed, oiled walnut, $14.95. First, use channel 3 for stations be- tween 88 and 100 mc and channel 4 for stations between 100 and 108 inc. A NEW DIMENSION Second, juggle the TV's fine -tuning control and the frequency of your local oscillator for best sound. Other possible IN TURNTABLES -12%" x 19" uses for this circuit are monitoring local airport, fire department, police DESIGNED TO FIT department- or taxi frequencies. END NARROW CABINETS

BRITISH DEAF AND BOOKSHELVES! WANT VISIBLE SOUND The Associated Press reports from London, England, that an organization called "The Campaign for Television for the Deaf and Dumb" has sent a resolution to British Prime Minister Harold Macmillan recommending: Translating the most important news bulletin each day into sign language. Transmitting one play a month with an interpreter giving the lines to the deaf. Presenting at least one sports event a month accompanied by a sign -language description. 01w televised church service each month with the pastor's sermon trans- lated into sign Ianguage. The request is understandable since British viewers, whether they can hear or not, pay a license fee of three pounds SPECIFICATIONS: Noise Level: -53db below average recording level; Wow and Flutter: 0.15% ($8.40) per year. Drive: Nylon, neoprene -impregnated endless belt. 2- Speeds, 331/3 and 45 rpm. NOTE: COMING SOON... ANOTHER GREAT DEVELOPMENT...Rek -O -Kut AUTO-POISE -makes any Rek -O -Kut tonearm you buy now -fully automatic

Rek -O -Kut Company, Inc., Dept RE -I I 38 -19 108th Street, Corona 68, N.Y. REK-O-KUT Please send me complete details on the new N -34H STEREOTABLE: STEREOTARLES Name Export: Morhan Exporting Corp., 458 Bway, N.Y. 13 Canada: Atlas Radio, 50 Wingold Ave., Toronto 19 Address City Zone State

NOVEMBER, 1 9 6 0 81

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www.americanradiohistory.com GIVE YOUR STORE THE IM M MEEt

What can you do when

you finish a service job and the owner tells

you to charge it?

The answer to this and other questions appears below.

By LEO T. PARKER * SERVICE technicians engaged reg- that I operated on a cash basis he would In subsequent litigation, the higher ularly in servicing TV sets and have told me that he would not pay the court held that a note is not cash pay- other electrical appliances are bill until 90 days. I did not know what ment. confronted daily with legal prob- to do, so I told him to pay me in 90 This higher court also held that there lems that could add up annually to a days. Maybe he will pay me and maybe can be no substitute for cash, and, if a substantial sum of money. he won't, as I have no credit approval contract or agreement for service fails For example, recently I received an on him. What do you suggest that I do to clearly state that credit is extended, interesting letter from Mr. W. C. White, in cases of this kind ?" cash is always implied. In other words, who owns and operates a TV service The answer is: The higher courts unless the service technician clearly and shop. He says in part: "Yesterday I very consistently hold that unless the distinctly agrees to credit or time pay- went on a call to a private home to testimony shows conclusively that be- ment, cash must be paid by the cus- service a TV set. I had had no previous fore a serviceman rendered services, tomer. business with this home owner. After or a seller delivered merchandise to a Furthermore, the service technician I had made proper repairs on the set, purchaser, an agreement was made is not obligated to inform his customer including putting in two new tubes, I whereby the serviceman or seller agreed before he does the work that cash must made out a bill for $18.50 and handed it to extend credit, cash payment is im- be paid. to the home owner. He told me to plied. Therefore, where a home owner re- `charge it.' I told him that I operate For illustration, in Zeff v. Harvey fused to pay cash after a service tech- strictly on the cash basis and have no Company, 315 Pac. (2d) .371, it was nician has repaired his TV set, the charge accounts. He said I should have shown that a service technician took a technician can do one of two things: told him that before I started to work cutomer's note for certain equipment, First, he may at once sue the home on his set, and that if I had told him when the latter told the service tech- owner for the amount due and posi- s Attorney at law, Cincinnati, Ohio nician that he could not pay cash. tively recover a court judgment against 84 RADIO- ELECTRONICS

www.americanradiohistory.com DOUBLES YOUR EFFECTIVE MANPOWER

, Fast! "lough Dogs

Save Half Your Time ur Profit! SteP UP YO

TELEVISION ANALYST for Black & White and Color

Ck&k oil &sutits- PutipaitiQ T otúiuTs By Easy Point -to -Point Signal Injection, Cc mbines all the features of both You See the Trouble on the TV Screen and the Model 1075 and Model A1Ci7 Correct it -Twice as Fast and Easy! COMPLE "E R F. and I.F. H -VOLT INDICATC R There's no longer any need to "lose your shirt" (and VIDEO TEST PATTERN YOKE and HI- VOL -AGE customers) -and worry about the lost hours you never TRANSFORMER TEST recover -on "tough dogs" or even intermittents. The COMPO!ITE SYNC remarkable B &K Analyst enables you to inject your Also Now Provides: own TV signal at any point and watch the resulting FM MOL ULATED AUDID test pattern on the picture tube itself. Makes it quick SWITCH -TYPE TUN ER and easy to isolate, pinpoint, and correct TV trouble in COLOR 'ATTERNS NEGATIVE BIAS SUPPLY any stage throughout the video, audio, r.f., i.f., sync, HOR ZO`1TA, and VERTICAL and sweep sections of black & white and color tele- PLAIE and GRID DRIVE AGC KEYING PUL vision sets - including intermittents. Makes external scope or wave -form interpretation unnecessary. Most B+ BOOST INDICATOR PICTURE TUBE MODULATION useful instrument in TV servicing! Its basic technique has been proved by thousands of successful servicemen the world over. The Analyst enables any serviceman to cut servicing time in half, service more TV sets in less time, really satisfy more customers, and make more money. Bak MANUFACTURING CO. Model 1076. Net, $29995 1801 W. BELLE PLAINE AVE CHICAGO 13, ILL. Available on Budget Terms. As low as $30.00 down. Canada: Atlas Radio Corp., 50 Wingold, Toronto 19, Ont. Export: Empire Exporters, 277 Broadway, New York 7, U.S.A. See Your B &K Distributor or Write for Bulletin AP16 -E

NOVEMBER, 1 S 6 0 85

www.americanradiohistory.com the home owner for this amount. win a favorable court judgment against Second, he may at once remove from the this customer. All he need do is file a repaired TV set all the new tubes and suit and at the trial show the unpaid like appliances that he installed and bank check to the court, which will then later sue the home owner and re- immediately hold the "paid in full" cover a court judgment for the labor receipt void and with no legal value. and service call. At the same time, the court will render In Havas y. Ray Lundy, 276 Pac (2d) a judgment against the customer in 727, the testimony showed that an ap- favor of Wilson for the full amount of pliance was taken to a service shop for the repair bill plus court costs. necessary repairs. The appliance was At this same meeting Wilson asked not fully paid for. On completion of me whether he can sue a customer and the repairs, the service technician re- recover a court judgment for a TV tained possession of the appliance be- repair bill on which "... the reasonable cost he issued a "paid cause his bill remained unpaid. ..." in full" receipt, but part of which the The higher court held that the service customer paid with a counterfeit bill. technician could remove the newly in- for a repair job. The customer refused The answer to this question is: Yes, stalled parts from the appliance before to pay the bill. Crawford sued the under ordinary circumstances, Wilson the holder of the conditional contract customer who had, as a witness, a man can sue and the court will issue a judg- could repossess it. The court held that who owned a repair shop located in a ment against the customer who paid the the conditional vendor was not entitled disrespectable and cheap neighborhood. repair bill with counterfeit money. This to the parts which had been installed in This witness testified that he would is so because -generally speaking - the appliance by the repairman. have done the same repair job for payment with counterfeit money is not $125. For comparison, see Clarke v. John- a valid payment. However, this is not son, 187 P. 510. Here a service techni- The higher court held that the home so in all instances, as the following cian installed parts and repairs in a owner must pay Crawford's $280.50 bill anecdote will show: mortgaged appliance. The court held because the testimony showed that other A man named White is said to have that the conditional seller who later proprietors of repair shops in better - registered in a hotel, and to have de- repossessed the appliance must pay the class, respectable neighborhoods con- posited in the hotel safe for safekeep- repairman for the new parts and labor. sidered Crawford's $280.50 bill reason- ing a United States bill for $100. That able. Reasonable bill is collectable This higher court explained that men Another important point of law was located in cheap neighborhoods natu- brought up to the writer recently by the rally will do service and repair work owner and operator of a TV service for less money than those in better or establishment. He explained that in high -class neighborhoods where rent is many instances the owner of a TV set higher and probably service technicians will order repairs without inquiring are paid higher wages. the cost. Then, when the bill is pre- sented, the home owner refuses payment Jury will decide on the grounds that the charges are too Here is another interesting legal high and that he did not agree to pay question: "Recently a service techni- such a high bill. cian went into a home and after in- Modern higher courts consistently specting a TV set told the home owner hold that if a home owner or appliance that he could put it in good condition owner wants to limit his expenditures for $87.50. The TV owner told him to for a repair job, he is obligated to have go ahead with the job. When the tech- "The jury will the service technician make a price or nician finished the job, the owner of decide." bid before the work is started. If the the set refused to pay $87.50, saying day the hotel proprietor used the $100 owner of the TV set or other appliance that he understood the service techni- bill to pay a long overdue debt to a real does not strictly follow this established cian to say that he would do the job estate broker, who in turn used the rule of law and allows the service tech- for $27.50. The question is what can bill to pay off an overdue debt owed to nician to do the repair work, the owner the service technician do to collect this a TV service technician. The latter was becomes automatically obligated to pay $87.50 ?" pleased with the settlement and, there- the "reasonable" cost of the repairs. The answer is: He should file suit upon, used the $100 bill to pay the What is meant by the term "reasonable" against this home owner and let the balance he owed a funeral director. The is that price which other technicians of jury decide the case. The jury will listen latter gave the bill to one Ellis who had "like" experience, reputation, and de- to all testimony and decide whose testi- furnished services to the funeral di- pendability would have charged to do mony is truthful and render its verdict rector. Then Ellis, in response to urgent the same job. accordingly. requests for payment of past due debts For instance, in a late case a litigant he owed to the hotel, gave the hotel named Crawford owns an appliance Bad check is no payment proprietor the $100 bill. The hotel pro- store in a high -class location. He ren- Some time ago I talked personally prietor immediately placed it in the dered a bill to a customer for $280.50 with a man named Wilson who is the safe. owner and operator of a TV repair shop A few days later White requested de- that employs about 26 service techni- livery of his previously deposited $100 cians. He told me that a few days ago bill. The hotel proprietor produced the a customer gave a bank check in pay- bill from the safe and gave it to White ment for a repair job, demanding a who thereupon lighted a match to it, receipt stating that the account was saying that it was counterfeit. "paid in full." Later the check was re- The important point is that the turned from the bank marked "insuf- counterfeit bill was satisfactorily used ficient funds." Wilson said the bill to pay off valid debts, and everybody remains unpaid because the customer connected with the transactions was states that he cannot be compelled to satisfied and happy. pay because he has in his possession the receipt showing that the bill was paid How good a witness? in full. Another rather unique legal problem "He may at once remove...." Quite obviously, Wilson can easily was presented very recently by an 86 RADIO -ELECTRONICS

www.americanradiohistory.com done on his or other appli- on a TV set is properly recorded, a ance. service technician has only a secondary lien to secure payment for his work. Law of minors [See Allied a. Shaney, 74 N.T . (2d) It is certain that a minor is not 723; and Lincoln v. Netter, 253 S.W. obligated on any ordinary contract or (2d) 260.] promise he makes. Hence, service or An important point of law is that repair work for a minor is a financial once ct service technician has Given up loss unless the minor voluntarily pays possession of a set on which money is ". .. and refused to give it ..." the bill. due for repair work, his mechanic's lien For illustration, in the late and lead- is forfeited. In other words, the instant ing case of Doenges v. Gillen, 328 Pac. the owner takes his set out of possession acquaintance. He said that when he (2d) 1077, the higher court said: of the service technician, the lien auto- goes into a home on a service call he is "An infant lacks capacity to make a matically becomes void. alone, whereas the home owner has firm and binding contract; in all such members of his family who may be used contracts lies the inherent weakness and Law of service guarantees as witnesses in future litigation and condition that the infant may disaffirm Modern higher courts consistently legal controversies. He wants to know the contract during his minority or hold that after the purchaser of a TV what chance he has to win a suit for within a reasonable time after reaching set puts it in operation, the seller is $68.50 he now has on his hands against his majority. The right to disaffirm is bound by any and all reasonable pro- a TV set owner. The owner says he has not lost by reason of the fact that the visions and guarantees relating to the witnesses to prove that the service infant has induced the making of the service he has agreed to give. However, technician told him that he would do contract by deliberate misrepresenta- the courts will not permit any pur- the job for $39.50 because of past tion of his age." chaser to impose on a seller, unless such favors the set owner had rendered the is in the Law of mechanic's lien imposition clearly expressed technician. contract. Obviously, such a case is farfetched A great deal of discussion has arisen For illustration, in one case a con- and hardly worth this space for con- from time to time over the legal ques- tract of sale contained a clause in which sideration. Nevertheless, it borders on the seller "guarantees that the pur- an unusual case where a TV repairman chaser shall be satisfied." was making change in the home of a Although the TV was reasonably customer. He laid a $20 bill on the TV. good and worth the purchase price, the Later the home owner picked up the purchaser continually and at unreason- $20 and refused to give it to the tech- able frequency requested the seller to nician, saying that he, the home owner, supply an unnecessary amount of serv- had put it on top of the TV set. ice in adjusting, repairing and otherwise All these unusual and unsatisfactory performing work on the set. occurrences breed personal combat. At last the seller refused to supply However, it is advisable in such cases more service. Then the purchaser to present the facts to a jury, who will notified the seller that he was not satis- listen to all testimony and render a fied, and since the seller had guaranteed verdict in favor of the litigant whose "... a minor is not obligated ... "satisfaction" the purchaser demanded testimony it believes to be true. The that the seller take back the set and jury may make its own decision, irre- tion: "If a conditional contract of sale refund the amount paid. He notified spective of faked testimony intended to of a TV set contains a clause to the the seller that he would not make other favor the owner of the TV set. In other effect that the conditional buyer will monthly payments when they became words, the jury may believe or dis- not encumber the set, does this render due. believe a part or all the testimony given a service technician's lien void ?" The seller filed suit and proved that by the TV set's owner and his witnesses, The answer is no. the set had given reasonably good serv- who contest a repair bill. The courts For example, in Champe v Con- ice, notwithstanding the complaints give little or no weight or consideration solidated Finance Corporation, 98 N. E. registered by the purchaser. In view of to testimony of relatives or close friends (2d) 925, the testimony showed that a this testimony, the higher court ordered of a litigant. This holds whether the man named Barnett purchased an ap- the purchaser to pay the balance due on suit involves payment for service, mer- pliance, paying part cash. He signed a the set. END chandise or in suits for damages by conditional sales contract which pro- injured persons. Generally speaking, if vided that Barnett would not attempt a customer fails to introduce witnesses to sell or "encumber the appliance dur- before the court to prove that the ing the life of the contract." service technician promised to do a job Sometime later, Barnett ordered the for less than the amount for which equipment repaired at a service shop he sued, the jury will decide the verdict but he did not notify the finance com- in favor of the service technician. pany that it was being repaired. After For example, in Reeves v. Child, 194 the repairs were completed Barnett Pac. (2d) 919, a workman sued a home decided that the costs were more than owner to recover a bill amounting to he could pay, and he so notified the $372.41. The property owner testified finance company. that the man had orally promised to do In later litigation the higher court the job for considerably less than the held that the technician could keep $372.41. On the other hand, the work- possession of the equipment to solve man testified that his oral agreement payment of his bill. The court said: was to complete the job for about $375. "The vendor, by entrusting the ven- Since the jury believed the work- dee (Barnett) with possession ... im- man's testimony, the court held him pliedly clothed him with authority to entitled to full recovery of this amount. contract for necessary repairs, so that Quite obviously, all service techni- such repairs were as though made by cians can avoid legal controversies over vendor's request or direction." the price for repair work by having On the other hand, some higher any stranger sign a printed agreement courts have held that where a chattel to pay a named price for work to be mortgage or conditional sale contract "... counterfeit money is not valid NOVEMBER, 1960 87

www.americanradiohistory.com The PR -500 Turntable ... .. a single speed (331/2 -rpm) turntable with an integrally

mounted arm . . . employs a

' somewhat unconventional drive system which results in a to- tally inaudible rumble level, and low wow and flutter. The arm is simple yet effective, with a mounting system which REV EWS makes the unit relatively insen- sitive to shock and vibration." "The arm tracks well at the lowest stylus forces recoin- mended by the cartridge manu- facturer." "The hum field surrounding the PR -500 is very low, and no dif- ficulty should be experienced from this source even with L_KE poorly shielded cartridges." . . the Stromberg -Carlson PR -500 performs in a manner comparable to that of the most expensive turntables and arms, yet sells for much less." "The PR -500 is an excellent value at $69.95." Hirsh -Houck Laboratory - THESE... High Fidelity Magazine, May 'ea

...hint at the performance of new

New Amplifiers ... New Speaker Systems

ASR 660 -an extremely clean, beautifully de- ASR 220C - an unusually versatile medium Three new, wide range speaker sys- signed stereo amplifier Continuous power: power stereo amplifier Continuous power: tems. A new elliptical tweeter with 36 watts (18 watts per channel) Music power: 24 watts (12 watts per channel) Music power a heavily silver -plated voice coil pre- (IHFM standard): 44 watts (22 watts per chan- (IHFM standard) 28 watts (14 watts per chan- vents harshness caused by cone nel) Total harmonic distortion: 0.6% at 18 nel) Total harmonic distortion: 0.7% at 12 breakup in conventional circular watts per channel Intermodulation distortion: watts per channel Intermodulation distortion: speakers. Woofers of extra -heavy cone 1% at rated output (4:1 ratio, 60 and 7,000 cps) 2%, at rated output (4:1 ratio, 60 and 7,000 cps) stock are capable of long, linear ex- Frequency response: 0.5 db, 20- 20,000 cps Frequency response: ± 0.5 db, 20- 20,000 cps cursions for outstanding low fre- Separate channel, clutch - type bass and Separate channel clutch - type bass and quency power handling without dis- treble controls Scratch filter (18 db /oct); treble controls Scratch filter (18 db /oct); tortion. Tweeter level switches Rumble filter "Twin T" filter, null at 20 cps Rumble filter "Twin T" filter, null at 20 cps included on all models. Enclosures Loudness contour switch; Balance control; Magnetic phono pre -amp with new, low noise are carefully matched to the woofer. Channel reverse switch; Program selector; tubes A plus B center-speaker terminals. Master gain control DC on pre -amp heaters Suggested Audiophile net: $119.95 Suggested RS511 59.95 to 84.95 Audiophile net: for low noise; A plus B center speaker (prices vary RS514 74.95 to 99.95 terminals. with finish) RS516 105.00 to 135.00 Suggested Audiophile net: $159.95 For the sheer joy of listening ... "There is nothing finer than a Stromberg- Carlson'

88 RADIO -ELECTRONICS

www.americanradiohistory.com The FM 443 Tuner... The ASE-880 Amplifier ...

The Etrorberg- Carlson FM -443, . . a compact integraed stereo one o: the least expensive IM amplifier rated at 32 watts per chan- tuners on the mariset, nel. Noteworthy ... it exceeds its approaches the pertormanm of rated pcwer substantially over most of the audio range, has excellent more expensive eq.ripmen-_ It power - handling capabilities at both is the-efore an especial y god ends of -he spectrum." value for anyone who wants. to obtain the highest level of per- "Each channel delivered 53 watts at harmonic distortion, or 48 watts formance in 3 moderate -pr ced 2% distortion. This is unusual in system." at 1% an ampl fier rated at 32 watts ..." "The distortion at 100% mo3u- "The distortion of the ASR -380 is very lation is about 1% for sig-els low at usual listening levels when stronger than 10 nicrovotts." correctly operated ... it has a rare "The sensitivity measurement combina -ion of very high gain and very

of the F 1.443, according to low hunt The amplifier has a number IHFM stardards, is amazing Its of spec al features, such as center usable sensitivity is 3 mac - channel output and a very effective volts, a figure not usually fend channel- 3alancing system, as well as in tuners in this price rah;e. the usual stereo control functions This high sensitivity has not found in all good amplifiers." been obtained at the, experse "Only 0.6 or 0.7 millivolts at the phono of IF banlwicth." inputs will drive the amplifier to 10 At normal "The -uner sells for $79.E4." watts output per channel. gain selings . the hl.m level is Hirsh -Houck L+boratorw- 10 watts even High Fid,'ity Magazrnc, Jun a'00 better than 70 db below on phono input. This is completely inaudible." "With a listening quality matching its laborato-y response, the Stromberg- Carlson ASR -880 must be considered a very goad value at its $19..95 price." Hirsh -Houck Laboratory - Ft-ph Fidelity Magazine. Sept. '60

Strombe rg- Carlson components like these:

New Tuners

FM- 443A -an improved version of the highly SR- 445A -a combination of the FM -443A and All the new Stromberg- rated FM-443 New, high -accuracy, precision an entirely new, wide -band AM section. FM Carlson components have so dial Precision components in de- emphasis specifications: identical to FM -443A AM fre- many impressive features, network, giving improved frequency response: quency response: Broad: 25 to 9,000 ± 11/2 db you'll find a visit to your ± 11/2 db AM noise 20- 20,000 cps ± 1 db Sersitivity: 35 micro- Sharp: 25 to 2,500 cps Strom berg- Carlson dealer volts for 20 db quieting - Improved local - level: 60 db below 1 volt output AM harmonic most rewarding. He will be distortion: less than 1% at 100% modulation distance control in RF stage for lowest distor- glad to demonstrate either tuning indicators for AM and FM. tion and best signal -to -noise ratio on both Separate an individual component or local and distant stations Total harmonic Suggested Audiophile net: $131.95 distortion; less than 1% full deviation. a complete Stromberg- Suggested Audiophile net: $79.95 Carlson Component En- semble. See him or write: Stromberg- Carlson, 1478- 011 North Goodman Street, Rochester 3, New York. STROM @ERG-CARLSON A DIVISION OF GENERAL DYNAMICS

NOVEMBER, 1960 99

www.americanradiohistory.com Sawtooth Sticklers

This quiz will show how good you are at associating waveform distortion with the distortion of a circle on a TV screen

By ROBERT P. BALIN resulting circles they will produce on SAWTOOTH vertical and horizontal the TV screen? It is to be assumed that deflection waveforms in your televi- a linear sawtooth (such as that shown sion receiver control the picture's ap- by the dotted lines) will produce a nor- pearance. A sawtooth with a straight mal centered circle on the screen. When slope beginning and the distortion pictured is in the vertical GONSET LOW -COST ending with the waveform, correct amplitude produces a linear the horizontal waveform is 2 -WAY RADIO sweep. This, in turn, will reproduce a assumed to be normal. The reverse is also true. In either case, however, video Built for rugged "industrial- type" circle, for example, that not only looks perfectly round but is also centered reception (required to produce the cir- service where dependability correctly. If the sawtooth is distorted cle) is not affected in any way. The de- is essential! because of defective components, the flection waveforms shown can repre- circle becomes sent either vertical or horizontal wave- Two models available: G -12 four -chan- distorted and displaced. Fortunately, every forms. nel unit, and lower cost G -11 single - waveform distor- channel unit. Ideal for making up tion produces a predictable change in The problem: find the distorted wave- 2 -way industrial communications sys- the shape of the circle. A good trouble- form that will produce a circle having tems for buildings yards ... ware- shooter can tell what one will look like the appearance shown. For each circle, houses ... aviation ...branch businesses by looking at the other. there is a corresponding waveform. . contractors. Also for fishing, boating, Can you match the distorted wave- If you got stuck answers are on page hunting -special events. 11 -meter forms shown by solid lines with the 134. Citizens Band radio offers virtually un- END limited business or personal usage in vehicle, office, boat or plane. Simple licensing -no exam or special skills ... merely fill out simple FCC form.

C.12 CITIZENS COMMUNICATOR Every feature for dependable operation under heavy business and commercial 8 use! Trans /rec channels are crystal - controlled for highest stability, ease of tuning. Features press -to -talk opera- tion, front panel channel selector, ANL, adjustable squelch, transmitter tuning indicator, built -in speaker. FCC type accepted. 9 Compact! fits into tight Quarters -only 2 41/2" H, 7" W, by 10" D, weighs only 11 pounds. Built -in power supply is uni- versal 12VDC /117VAC (optionally available with 6VDC /117VAC) oper- ates from power mains or vehicular battery. 3 10 C -11 CITIZENS COMMUNICATOR Similar to G -12 except for single - channel operation, and mounting arrangement (3 models: 6VDC, 12VDC or 117VAC). G -12 149.95 per unit G -11 124.50 per unit 4

SUGGESTED PRICE INCLUDES P -T -T MICROPHONE AND TRANS /REC CRYSTAL FOR ONE CHANNEL.

Write for details and FREE Citizens Band radio booklet! 0 GONSET DIVISION Dept. RE 5 12 Young Spring & Wire Corp. 801 South Main Street, Burbank, Calif. Gentlemen: Rush complete details on your Citizens' Band radio, and free booklet

NAME 6 13 ADDRESS LCITY - - - ZONE STATE GONSET DI, vN m of l uunj .S1ru n/{ R It 801 SOUTH MAIN ST., BURBANK, CALIFORNIA 7 14 90 RADIO -ELECTRONICS

www.americanradiohistory.com Need a 100 -kc signal source?

PNP -NPN This oscillator uses no tuned circuits TRANSISTOR and almost any complementary pair OSCILLATOR of transistors may be used

THIS simple oscillator is a construc- By F. T. MERKLER resistors and one paper capacitoe are tion must for service technicians, mounted on a small phenolic ward experimenters or anyone else who 2 inches high by 11%3 inches in diameter. (photo). In the model, the parts were - needs a precision signal source at The crystal you use will determine the run point to point, with leads ihrough a reasonable cost. It can also be used size of your oscllator. small holes in the board. The transistor to power an rf bridge, drive flip -flops, sockets were glued to the top edge of logic circuits or a square -wave gen- Construction the board with service cement. care- erator. Any reasonable parts layout will do. fully solder all connections. Follow the Complementary transistors make for There are no critical leads or circuit schematic (Fig. 1). a stable, easy -starting crystal oscil- dress to worry about. Barring an actual CAUTION! Remember one of the lator designed to use a minimum of wrong connection, the unit will perform transistors is p -n -p, the other n -p -n; The parts. crystal forms the feedback as designed. Interior view shows parts layout. path from emitter to emitter, making Five 1/2-watt 10% tolerance carbon Crystal just visible behind rhassis. the circuit the dual of the vacuum -tube cathode -coupled . Direct coupling between the p -n -p and n -p -n transistors insures stability over the temperature range of - 5° to +55°C. The p -n -p transistor, V1, is connected in the common -base fashion. The n -p -n transistor, V2, is connected common - collector. (Fig. 1). This method of cou- pling makes Vl's collector current stabilize V2, eliminating the possibility of thermal runaway. The high stability allows large tran- sistor- parameter variations ( "Predict- able Design of Transistor Amplifiers," R. B. Hurley, Tele -Tech & Electronic Industries, August, 1955). Almost any combination of p -n -p and n -p -n transistors in this circuit will re- sult in close to sine -wave output. Audio types, drift transistors, converter or if amplifier types will all work. Just be sure that one is a p -n -p and one is an n -p -n. The ones shown in the schematic were used in the original oscillator. If you have none in your parts box, buy these types. The size and shape of the original oscillator was based on the size of the crystal used (Bliley AR 23 -W) and the small wooden box that was available. The AR 23 -W is a surplus crystal no longer manufactured, but the KV -3 by the same company is quite suitable. This unit mounts in a standard octal socket. James Knights Co. also makes a 100 -kc crystal, type H -9. This unit is

BENCH Unit is small and compact. When tested by a member of oscillator would have to be calibrated first. Don't forget, any the staff of RADIO -ELECTRONICS, it produced the 100 -kc wave- error is additive. I kc off at 100 kc becomes 10 kc off at I mc. form specified by the author. When the oscillator is brought close to a radio receiver, oscillation is heard at 100 -kc intervals. Two- transistor crystal oscillator. Almost any transistors can be used as long as they make a Uses almost any pair of complementary transistors. p -n -p n -p -n pair. Several combinations were tried and all worked Useful range-100 kc to well into the megacycles (on har- well, with only slight variations in the waveform. monics). There is no fine -frequency trimmer in this unit, so if may not May be used without crystal as sawtooth generator or code be exactly on frequency. For any exact calibration work, the oscillator. Compact and inexpensive.

NOVEMBER, 1960 91

www.americanradiohistory.com a yew steda.a of b.oad - - rformance from UNIVERSITY

NO OiNEB PBOFES' ONA MICROPHONE AT ANY PRICE CAN II WNpi THIS ONE CAN!

Never before has there been a microphone FEATURES OF THE UNIVERSITY like this ... and it's just one of six profes- PROFESSIONAL MICROPHONES sional models that herald the entrance of University into the field Exclusive "Unilar" diaphragm assures ex- of microphones. tremely Each sets a new standard of wide-range, wide response range ... from as low as distortion -free performance ... with 30 cps to as high as 20,000 frequency response available cps. Rugged generating as low as 30 cps, as high as element is indestructible in normal use. 20,000 cps. Each offers the lo Internal ele- years- ahead -of- its -time con- i ments of shock -mounted cept of modular flexibility. models float in vibration - Each is styled with clean, un- free foam insulations. Im- cluttered lines totally adapt - A pedance matching simplicity table to every environment. (choice of two low, one high) with press -on connectors built To accomplish all this, Univer- into every accessory. No tools, sity drew upon its more than soldering, or rewiring. Trend- two decades of leadership in setting exterior design with sound, and applied all this vast smart modern finishes ... just experience to the challenge of right for every application. producing a better microphone than had ever been known before. University - the leading manufacturer of speakers - now sets the pace in microphones.

MODULAR FLEXIBILITY .. . E a major breakthrough in micro- phone design ... gives you total All these accessories available for interchangeability between complete modular flexibility: [A] all Model CCIO Cable Adapter microphones and all accessories with 18' at cable, $6.00. [B] Model PA10 Can- all times. Need a microphone non Plug Adapter, $6.30. [C] Model with a switch and another with- SPI O Cannon Plug Adapter with out... or for slide -on and screw -on switch, $6.90. [D] Model CA10 Can- stands ... or for cables with and with- non Plug and Cable with push /action out cannon plugs? Buy just one Univer- latch -lock and 18' cable, $6.00. [E] Model sity microphone plus only the adapters SSPIO Stand Adapter with switch and re- you need, and you've got them all! You ceptacle for cannon plug, $11.10. [F] Model SAIO Slide -on Stand Adapter $4.20. All prices don't pay for features you don't need . . . professional net. For further details, write you don't compromise to meet a price. That's true modular Desk J -11, University Loudspeakers, Inc. flexibility, and you 80 S. Kensico Ave., White Plains, N.Y. A get it only from University. Division of Ling -Temco Electronics, Inc. 92 RADIO -ELECTRONICS

www.americanradiohistory.com double -check your polarity at the tran- sistor sockets. The p -n -p transistor (V1) collector pin connects to load resistor R3, and R3 connects to the negative voltage source. The n -p -n tran- sistor (V2) collector pin goes direct to ground (which is positive). Reverse

2NI40 2N170 - 4.sV+ BATT% 22K S ON -OFF' MODEL 4025

MODEL 401 OM N I- DIRECTIONAL DYNAMIC Professional broadcast microphone for diversified Fig. 2- Output waveform with 1.:110-kc broadcast applications. Also ideally suited for every JI 2N170 transis- quality sound system: night club, church, school, crystal and 2N140 and commercial and industrial p.a. Exclusive "Unilar" tors used in the oscillator. diaphragm. Response: 40- 20,000 cps. $43.50 pro- OUTPUT fessional net. MODEL 402S OMNI - DIRECTIONAL J2 DYNAMIC (SHOCK MOUNTED) Deluxe ver- sion of Model 401, shock -mounted to prevent RI -47,000 ohms mechanical feedback and pickup of spurious noise. R2 -6,800 ohms Response: 35- 20,000 cps. Otherwise identical in R3 -3,300 ohms performance to Model 401. Exclusive "Unilar" R4 -1,200 ohms diaphragm. $47.70 professional net.* R5 -2,200 ohms All resistors 1/2 waif, 10% C-0.1 µf, 200 volts XTAL -100 kc Vl -p -n -p transistor (2N140) V2 -n -p -n transistor (2N170) JI, 2- phone -tip jacks BATT-4.5 volts (3 penlight cells in series) S -spst toggle Transistor sockets (2) Box or case to contain oscillator Battery holders Phenolic board (chassis) Miscellaneous hardware Fig. 1- Schematic. Green and orange paint is used to color code the transistor sockets. MODEL 403L MODEL 404L Front view of unit. Power switch is lo- MODEL 403L TELEVISION LAVALIER these connections and the circuit will cated on top of wooden box. Extremely rugged professional lavalier only 31/2" not oscillate. In the model the sockets long ... for telecasting, broadcasting and recording where uncompromised quality reproduction, mini- were color -coded; Vl's socket was given mum weight and unobtrusiveness are required. Per- a dot of orange paint, V2's a dot of ground to be used in a series - resonant formance factors exceed previous lavalier micro- is purchased, the ultimate fre- phone standards. Exclusive "Unilar" diaphragm. green. circuit Over -all response: 60- 20,000 cps. $52.50 profes- Oscillator output is taken from the quency accuracy will depend on the sional net. emitter of V2 and ground. A pair of crystal's frequency tolerance and the MODEL 404L BROADCAST LAVALIER terminals temperature at which it is operated. Designed for exacting broadcast applications re- tip jacks serve as the output quiring specifications of the large omni- directional in the model. Since these terminals are For high -order precision, some form of microphones. For the first time, a lavalier micro- connected to the battery through R5, oven with automatic temperature con - phone that exceeds performance of full -size units, s beyond yet is only 4IA" long, 1- 3/32" in diameter. Exclusive shorting the output terminals will draw trol is needed. Such a system "Unilar" diaphragm. Over -all response: 50- 20,000 2 ma from the battery. The oscillator the scope of this article. cps. $57.00 professional net. operates at a low power level, 6 mw. The original oscillator with the !N140 This provides a long life expectancy for and 2N170 transistors will work with all components. No adjustments are crystals in the range of 70 kc to 400 Icc. needed to put unit into operation. Care- If a sawtooth output is required, sub- fully check all wiring, connect a scope stitute a paper capacitor for the crystal. across the output terminals and turn A standard headphone in se-lies with on the power with switch S. The ap- a 0.1 -µf capacitor and connected in proximate waveshape is shown in Fig. place of the crystal, makes the unit a 2. If a scope is not available, turn on handy code oscillator (key the unit at the oscillator and place it close to a one of the battery leads). Use the unit broadcast receiver. Beats and whistles as a high -gain low -level ampiiier by will be heard as the receiver is tuned connecting an input coupling capacitor across the low end of the band. The to the emitter of V1 and leaving out the MODEL 501 MODEL 5025 frequency of the output will be very crystal. Take output from J1 and J2. END MODEL 501 PROFESSIONAL DYNAMIC close to 100 kc. If a crystal which is CARDIOID Finest quality full-range reproduction under diverse acoustic conditions. Cardioid pattern rejects unwanted background noises and room reverberations, allowing non -critical placement of A NEW COMPLAINT microphone. Exclusive "Unilar" diaphragm. Re- sponse: 35- 15,000 cps. $75.00 professional net. We at Howard's Television (1070 A was right here and heard my husband MODEL 5025 PROFESSIONAL DYNAMIC give an estimate of $10. You knew CARDIOID (SHOCK MOUNTED) A deluxe St., Hayward, Calif.) thought we had you shock -mounted microphone designed to prevent heard everything in the nature of that the bill would be $10 before you mechanical feedback and pick -up of spurious noise. your set." Response: 30- 16,000 cps. Otherwise identical in per- complaints from ingenious customers, left formance to Model 501. Exclusive "Unilar" dia- but this was a new one to be added to He set his face in harder lines. "Yeah, phragm. $87.00 professional net. a long list. I know. That was just an estimate. It *microphone only. My husband gave a Mr. S. an esti- would never happen in a million years mate of $10 to repair his set. Mr. S. that the bill would come out exactly at went away happy. He asked for the bill the estimate. Might be $9.99, or $10.35 after he had picked up his set. He maybe, but $10, never!" glanced down at it. Then his face and Angry color flooded his face as he body bristled. "What's the idea of this grudgingly paid the bill and went away A Division of Ling -Temco Electronics, Inc. bill for $10 ?" he challenged me. muttering, "$10! Never in a million I was puzzled and reminded him, "I years! " -Myrtle Spracklen NOVEMBER, 1960 93

www.americanradiohistory.com * CREI's Extension Division offers Engineering Technicians and Engineers a combination of courses in advanced electronic engineering technology. * The program is designed to meet your present and future employment requirements and to increase your professional status and earning power. -this CREI College -level Home Study Program in Electronics is Compa- rable in Technological Content to Advanced Residence Courses!!!!!

The CREI home study program is the culmina- modern advanced education, and there is every indi- tion of 33 years of working closely with leading cation that this shortage will increase in the years companies and Government agencies in the critical ahead. New jobs are being created daily through the field of electronics. This accredited program is de- application of electronic developments in missiles, signed for men already employed in a technical ca- space exploration, automation, instrumentation, pacity in the electronics industry. computers, telemetering and many other fields. This CREI college -level program is comparable in These positions must be filled by men with modern technological content to advanced residence courses. advanced education, which fact is evidenced by the You may complete the program in 2 to 4 years, de- experience of the CREI Placement Bureau, where pending on the amount of free time you can devote the demand for graduates and advanced students to study, and the courses you choose. far exceeds the supply. It is of interest to note that For several years the electronics industry has suf- Help Wanted ads frequently specify "CREI educa- fered a serious shortage of technical personnel with tion or equivalent."

94 RADIO -ELECTRONICS

www.americanradiohistory.com CREI is recognized by Over 20,500 CREI students industry and government find home study Another reason why CREI men are respected and eagerly sought by industry and Government agencies convenient and profitable alike is the accreditation and enthusiastic approval ac- corded the CREI home study program in advanced You can pursue the CREI program while you con- electronics. We co- founded the National Council of tinue your regular full -time job. You study at home Technical Schools, and we were among the first three during hours chosen by you. You are not rushed and you technical institutes whose curricula were accredited by have plenty of time to do your best. the Engineers' Council for Professional Development. The courses are prepared in easy -to- understand for- Further, the U.S. Office of Education lists CREI as "an mat, and the CREI staff of experienced instructors institution of higher education." guides your progress all along the way. These instruc- Of equal importance, we believe, is the appreciation tors stand ready to assist you whenever you need help. expressed by industry and government for the CREI You will find our personal assistance and guidance effi- programs. Dozens of major electronics organizations, cient and helpful, because 33 years of experience in ranging from industrial giants to the Government's home study teaching enables us to anticipate questions Voice of America, have agreements with CREI for en- in our lesson material. rollment of students under company sponsorship. U.S. Many CREI students have learned that they do not Navy electronic personnel in the number of 5,240 are have to wait until they have completed the program to enrolled in CREI extension programs. The British realize significant improvement in their status and in- Royal Air Force, Army and Navy have approved CREI come. The very fact that you are ambitious enough to courses under their tuition assistance plan. The follow- pursue this college -level program enhances your oppor- ing companies comprise only a partial list of the organi- tunities for rapid promotion. Project leaders and super- zations which not only recommend CREI study but visors recognize the value of CREI education. actually, in many cases, pay all or part of the tuition for employees taking CREI courses: National Broadcasting Company How you benefit from CREI Jerrold Electronics Corporation Pan American Airways program of home study Radio Corporation of America Canadian Aviation and Electronics CREI students are electronic engineers and techni- Federal Electric Corporation cians engaged in every phase of electronics. They am in The Martin Company research laboratories and manufacturing plants. They Voice of America work on the design, development and production of the Canadian Broadcasting Corporation latest computers; on the latest military and civilian air- Northwest Telephone Company craft; on the electronic equipment associated with the Commercial Cable, Incorporated Nation's missiles and space exploration efforts; on com- Canadair Limited munications equipment of all kinds; they maintain Columbia Broadcasting System electronic equipment for the air lines, the Government All America Cable and Radio and private corporations. You will find CREI students Canadian Marconi in all 50 States and in most foreign countries of the Mackay Radio free world. United Air Lines Gates Radio Company To the serious- minded and ambitious CREI student Mohawk Airlines our home study program offers a series of important Florida Power and Light Company benefits: 1. You gain a solid college -level education in advanced electronic engineering technology; you keep abreast of continuous new developments in the field. RESIDENCE SCHOOL 2. You can gain higher status and enjoy the increased .. in Washington, D.C., for those who can attend respect of your associates. classes. Day and evening classes start at regular inter- 3. You facilitate more rapid professional advancement vals. Graduates earn AAS degree in 27 months. Elec- with corresponding significant increases in pay. tronics experience is not required for admission. 4. You gain the personal satisfaction that comes from working and communicating intelligently with your QUALIFICATIONS FOR CREI ENROLLMENT technical colleagues and superiors. FACTS ABOUT TUITION, REGISTRATION If you have a high school diploma or equivalent, basic elec- tronic training and practical experience in electronics, you WRITE FOR DETAILED 44 -PAGE BOOK of curricula and meet the minimum requirements for enrollment. Tuition is other information about CREI, entitled "Insurance for Your reasonable and may be paid monthly, if you wish. Veterans Future in the New World of Electronics." USE POSTAGE -?AID qualify for this program under the GI bill. CARD ATTACHED, or write to Dept. 1411-G.

ECPD Accredited Technical Institute Curricula The Capitol Radio FOUNDED 1927 3224 16th Street, N.W. Engineering Institute Washington 10, D.O. Dept. 1411-G

NOVEMBER, 1960 97

www.americanradiohistory.com 6E5 for FIIEE! TRANSISTOR CIRCUITS

Olson Radio Catalogs Simple dc-to-dc converter lets you add an indicator tube FOR ONE YEAR to your all- transistor devices * 8 Different Issues * All Bargain Packed By RUFUS P. TURNER selenium rectifiers (RECT 1 and REGT 2) and two 50 -µf 150 -volt electrolytic FREE One Year Subscription YOU don't have to do without an capacitors (C1 and C2). The full -load to OLSON RADIO'S Fantas- electron -ray indicator in low- voltage, dc output voltage of this circuit is ap- tic Bargain Packed Catalog - battery- operated equipment such as Unheard of LOW, LOW proximately 100. WHOLESALE PRICES on transistor receivers, amplifiers and test The battery can be four 1.5 -volt dry Brand Name Speakers, Changers, Tubes, Tools, instruments. The indicator can be op- cells in series. If a storage battery is Hi -Fi's, Stereo Amps, Tuners and other Bargains. erated by an all- transistor converter used, the tap can be at 4 volts (two circuit. cells) instead of the specified 3 volts. The diagram shows a circuit for op- For short-term use, as in bridge bal- Another OLSON Bargain! erating a 6E5 indicator tube from a ancing, signal tracing, etc. where the 6 -volt battery tapped at 3 volts. The device is in operation only a few min- tube's heater receives the full 6 volts, utes at a time, four size -D flashlight NEW! TUBE TESTER while 3 volts drives the converter cir- cells will do. END cuit which supplies the high dc voltage for the plate and target. The voltage stepup is provided by a RI, 2 -10 ohms, I watt R3, 4-I megohm, /2 watt 6.3 -volt filament transformer, T. Two CI, 2 -50 µf, 150 volts, electrolytics 2N255 transistors (V1, V2) and two RECT I, 2- selenium, 130 volts, 20 ma. miniature (Federal 1159 or equivalent) 10 -ohm 1 -watt resistors (R1 and R2) Sl -dpst toggle form an oscillator circuit with the T- filament transformer: primary, 117 volts: secon- dary, 6.3 volts ct, 1 amp (Merit P -2944 or transformer's center- tapped 6.3 -volt equivalent) VI, 2 -2N255 winding. V3-6E5 The high ac voltage delivered by the Sockets, 9 -pin miniature, for 2N255's (2) FACTORY WIRED 51483 117 -volt winding is rec- Socket, 6 pin, for 6E5 transformer's Chassis, to suif 518aß tified and doubled by two Miscellaneous No. TE -148 No. KB-92 miniature hardware - COLLECTOR Olson Radio brings you the smallest lowest priced do- CONNECTED mestic tube tester on the market. Only 6%" w x 21/2" d x O TO CASE 51" h. Not just o filament checker, but a real lobe tester that checks each section of multi -purpose tubes for qual-

ity of emission and inter- element shorts. Tests for opens RECT I and intermittents also. Checks all miniature 7 and 9 pin 2N255(2) SEL/ 130 V/ 20 MA tubes plus 8 pin octets and 8 pin !octets. Quality of OSC cemission is indicated on easy to read 2" meter with 2 VI olor dial. 10 switches select individually each element INDICATOR B ON - OFF 6.3 V CT so that short tests can be made easily and quickly. Neon RI 1 c V3 lamp indicates shorts. This tube tester will also test bal- +3 V 6E5 last tubes and tubes. Operates on 117 o oo- colts AC. Completely flexible and obsolescent proof. R2L SI-a SI-b -8A Comes with instructions and tube charts. o+ SIGNAL 3V INPUT Picture Tube Test Adaptor No. TE- 149...... Ea. $3.83 o- OSC RECT 2 HTR V2 SEL/130V / 20 MA _3 ¡ 1/N6

Indicator circuit for all- transistor instruments. Fill in coupon below for your FREE one year subscription to Olson's Bargain Packed Catalog. To order Tube Tester, simply check wired or kit model ( also Adopter If desired) and send remittance along with coupon. (In- lude enough for postage or parcel post shipment. Send AMPLIFIER TEST-LOAD BOX $2.00 deposit for C.O.D. orders.) in conventional rheostat fashion. Holes FREE Olson Catalogs for One Year If your shop handles an appreciable were made in the plastic Tube Tester Kit No. KB -92 $14.83 amount of audio amplifier servicing, for the leads of a hot soldering iron Tube Tester Wired No. TE -148 $18.83 you may find this idea helpful. To save box with the tip Picture Tube Test Adaptor time often wasted looking for the cor- and the edges smoothed off with a file. No. TE -149 $ 3.83 rect resistor with a power rating suffi- When an amplifier is to be instru- cient to be used as an amplifier out- ment tested, the load box is simply NAME put load, I constructed a variable clipped across the output terminals and

ADDRESS output -load box. I mounted a 25 -ohm adjusted for the correct load. Although 100 -watt potentiometer (Ohmite K0448) a noninductive resistance should be CITY ZONE STATE in a small plastic pasts box, added a used, I have found that the load box is bar knob and calibrated the pot with satisfactory for most tests because fre- OLSON RADIO an ohmmeter for all the common out- quency response.is usually not affected CORPORATION put impedances encountered in audio until the frequencies of the signal being work. A pair of short leads with alli- tested approach 100 kc.- Warren J. 713 S. Forge St., Akron 8, Ohio gator clips were soldered to the pot Smith

98 RADIO -ELECTRONICS

www.americanradiohistory.com 7W/teledf/Weree9 MA G A Z I N E PDT1NTS SURVEY on TELEVISION ADDER Patent No. 2,937,286 in MOTELS reports ... T. H. Bonn and J. P. Eckert, Jr., Philadelphia, Pa. (Assigned to Sperry Rand Corp.) This adder provides output only when one of its two inputs is energized. Such a device is useful in binary counting. For example, adding 1 plus 1, or 0 plus 0, should (disregarding the carry) give zero. Adding 1 plus 0 should give 1. This adder requires no operating power. It is comprised of a transformer and diodes.

OUTPUT INPUT A LOAD

INPUT B

Assume that a pulse exists at input A only. Current flows through the primary using input B as the return path. The secondaries are op- positely wound (note dots) so one will pass current, depending upon which diode permits it. i On the other hand, no output exists when sig- nals are present at both A and B due to cancel- lation. V -R TUBE CIRCUIT JE 1RO LO Patent No. 2,944,206 FACT: More Charles B. Brehm, Windsor Locks, Conn. (As- signed to United Aircraft Corp., E. Hartford, Conn.) TV Master Antenna Systems The firing voltage of a VR tube is higher than its regulating voltage. For example, the OAS fires at 105 volts and regulates at 75 volts. In a conventional circuit (Fig. 1), we want R to be Have Been Installed Than R VR TUBE LOAD The Next 4 Makes Combined! While the survey shows a tremendous acceptance of Master Antenna Fig.l Systems-56% of the Motel operators report having one -there is small to permit firing, but it should be large to limit current to that required by load and tube. still an overwhelming segment of the market yet to be sold ! And In the new circuit (Fig. 2), RI -Rc form construction of new Motels -new markets -is progressing at a a divider that delivers slightly more than regu- lated voltage across the load. R2 is chosen for faster -than -ever pace! minimum VR current through the tube (5 ma). Look to Jerrold -the leader in Master TV Antenna Systems -to help you get your share of this profitable business. The top portion of this advertisement is now appearing in AMERICAN MOTEL. MAGAZINE doing a strong "pre- selling" job on your Motel prospects! EL ... And remember -your trained Jerrold distributor is always ready to show you how to plan and install Master Antenna Systems quickly, easily, profitably. Fig.2 Yes, look to Jerrold -the world's largest manufacturer of TV When the circuit is switched on, EL drops profitable thing to do! to approximately the regulated voltage, while distribution systems and equipment. It's the a full Es is available to fire the voltage regulator through R2. This is possible because diode D Valuable Installation Handbook... remains blocked. After firing, D allows a small FREE! current flow through the VR tube. Thus lower A "How- to- do -it" manual -normally selling for S1- supply voltages may be used. complete that covers almost every conceivable type of installation. WAII Included are 150 typical system layouts in detail. MISSILE MEASUREMENTS Jerrold Electronics Corporation Patent No. 2,944,250 Distributor Sales Division John R. Outt, Malvern, Pa. (Assigned to General Dept. Ids -92, Philadelphia 32, Pa. Electric Co.) Gentlemen: This invention uses solar cells to study con- Please send me the "TV Distribution Handbook. ' I on, enclos. ditions in space. Solar battery BATT 1 is ing 25c to cover handling costs and postage. Nome COSMIC DUST Firm Address BATT 4 City Zone_SRate BATT 17

- .111i111111 ELECTRONICS CORPORATION, Phila. 32, Pa. BATT/ 2 JEß601,D Jerrold Electronics (Canada) Ltd., Toronto BA T 3 Export Representative: CBS International, New York 22, N.Y. NOVEMBER, 1960 99

www.americanradiohistory.com situated near the nose cone of a high -speed missile. The missile rolls during flight, so the sun's rays reach the cell periodically. Therefore ac is generated, its frequency being equal to the roll rate of the missile. BATTS 2, 3 and 4 are connected in series, so the sun always shines on at least one. Their Cut servicing output will be nearly constant. However, it gradually decays due to the sandblasting effect of tiny meteors. Since cell output is high, no amplifiers are and needed. The voltage information may be trans- mitted by radio as usual, to indicate roll rate and meteor activity. installation time RADIATION DETECTOR Patent No. 2.942,110 on all Kurt Lehorec, S. Williamstown, Sass. (Assigned to Sprague Electric Co., N. Adams, Mass.) No batteries are used here. The radiation crystal -controlled senser is a barrier -layer cell, sensitive to beta

BARRIER LAYER CELL -4- LIGHT

rays. Output is about 1 microamp, which is amplified by the transistor. A solar cell powers the transistor. The meter should have a maxi- 2 -WAY RADIO TEST SET mum deflection of 25 ma. tisor DIRECT -COUPLED AMPLIFIER Compact, portable, use it an) N here. Designed to assist you in the following applications: Patent No. 2,936,345 CHECKS WIDE RANGE OF CRYSTAL TYPES! Checks fundamental types at funda- John F. Kinkel, :Iltarlena, Calif. (Assigned to mental frequency -5th and 7th overtone types at fundamental frequency - Bell & Howell Co., Chicago) 3rd overtone types in 25 -30 me range in special overtone circuit. This amplifier handles high power for motors, RF POWER INDICATOR FOR DIRECT OR REMOTE METERING! Simply place next servos, etc. V1, has a high amplification factor is low use 15 and coupled to V2, a -plate- resistance tube. to antenna or ft. remote metering cable furnished with unit. They form one channel. A second channel, made MODULATED RF CRYSTAL -CONTROLLED SIGNAL GENERATOR! up of V3 and V4, is identical with the first. However, V2 and V4's currents flow in opposite MODULATION CHECKER! BEAT FREQUENCY DEMODULATOR! directions through the load. PLATE MILLIAMMETER FOR RF TUNING! AUDIO FREQUENCY SIGNAL GENERATOR! MODEL sop -Fully transistorized -the perfect // V2 "assist" instrument even for the fully equipped shop N ET + LOAD ONLY GRID CIRCUIT TUBE TESTER VI 1/4

WITH FULL TV TUBE COVERAGE! A o Complete coverage all TV tube types -including voltage amplifiers, power output and heater -type diodes, hundreds of Foreign and INPUT Industrial types, types with Grid, Plate or Cathode caps. Test for o Grid Emission, Leakage, Shorts and Gas in one operation -indicates B results instantly. Offers two exclusive new tests: I. Cathode Con- tinuity Check; and 2. Complete Inter- Element Short Test, with CoOM shorts identified to pin numbers. Wired and factory tested in sturdy metal case (GCT -9S) or portable carrying case (GCT -9W) -with easy to read tube set -up data and "Piggy- Back" caddy adapter. Normally Vl and V3 are blocked and V2 and V4 are conducting, but load currents cancel. MODEL MODEL A positive signal at A causes V1 to conduct, $3295 $3495 lowering the output from V2, and power is fed GCT -9S NET GCT -9W NET to the load. Likewise, a positive signal at B reduces V4 conduction and results in power at WRITE TODAY! the load, this time of opposite polarity. NEW LITERATURE AND SPECI- The input signal determines whether V2, V4 FICATIONS AVAILABLE ON ALL SECO ELECTRONICS, INC. or both will conduct and how much. END SECO TEST EQUIPMENT. 5015 Penn Ave. So. Minneapolis 19, Minn.

EAST CANADA: Daveco Agencies, Ltd., Montreal. Quebec WEST CANADA: Ron Merritt Co., Vancouver 1, B. C.

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+è pUIExR Spray it or Drop it Just Press and Or, if you prefer, use SA pm* ser, . . . this handy eye -drop- whoosh aero- TV PaO sol OUIETROLE per and just a drop uatu-neetaì quickly and easily or two of quality AND RADIOS f LUBRICANT TV cleans as it lubri- OUIETROLE does the Tuner! .¡}...a CLEANER cates. lob perfectly. st gis tofu 11.,, Either way, make sure it's QUIETROLE CONIeOIS d SIItt r,s Q UIE L E Cowpony, Inc. TRO ln Canada: /73-14611 CROSS CANADA ELECTRONICS , Spartanburg, South Carolina 61 Ontario SI., S., Kitchener, Ont. "I was wrong. It i, not sync buzz!" 100 RADIO -ELECTRONICS

www.americanradiohistory.com ...vi,5vMerzo0 ete/ look to this sign of assurance!

The Distributor displaying this sign will solve your tuner problems al a profit to you. AUTHORIZED He has available the New Standard Tuner Replacement Guide, including replacement parts listings. This is the only Guide of its kind in the world. Covers all Standard tuners produced COIL through 1959. Includes replacements for many s tuners not produced by Standard. TV TUNER DIST RIBUTOR He handles our 48 -hour Factory Guaranteed Repair Service and Trade-In Allowance on unrepairable Standard tuners. GUARANTEED REPLACEMENT TRW FACTORY SERVICE - PARTS

See This Authorized Distributor Today standard kolisman INDUS T R I E S INC. Formerly Standard Coil Products Co.. Inc. 2085 N. HAWTHORNE AVENUE, MELROSE PARK, ILLINOIS

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new - PRODUCTS

FM TUNER KIT, LT -In. Wide-hand. Silver -plated. Preassembled, prealigned front end. Tube sockets, terminal strips and transformers premounted. Carrying case with handle opens to make work table. Full -color instruction book with there is no margin for error when striving for the ultimate in stereo sound re- creation part charts for mounting in order of use. Color- coded, precut, prestripped and pretinned wires. Built -in -kit meter aligns tuner. -H. H. Scott, Inc., Dept. P, 111 Powdermill Rd., Maynard, Mass. SHURE STEREO PREAMP M65. Extra volt- fUóf age and equalization for operation of magnetic cartridge with amplifier de- HI -FI PHONO CARTRIDGES Tiny though it is, the cartridge can make electrical impulses ... without adding or or break a stereo system. For this breath- subtracting a whit from what the recording takingly precise miniaturized electric gen- engineer created. Knowing this keeps erator (that's really what it is) carries the Shure quality standards inflexible. full burden of translating the miles -long Shure Brothers, Inc., 222 Hartrey Avenue, undulating stereo record groove into usable Evanston, Illinois. CARTRIDGES Standard M8D. A superb blend of quality and economy $16.50 Custom M7D. Widely acclaimed; TONE ARMS IL moderately priced. $24.00 Studio Dynetie. Integrated arm Professional M3D. Overwhelming and cartridge. Cannot scratch signed for ceramic. Single rotary switch choice of the critics. $45.00 records. $89.50 for function selection. Operates from Laboratory Standard Model M3LS. Professional Independent Tone Arm. 117 -volt 60 -cycle outlet. Dual input and Individually calibrated, limited For any quality cartridge . output jacks accepting standard phono quantity $75.00 stereo or mono. $29.95 plugs. -Shure Bros., Inc., 222 Hartrey Ave., Evanston, Ill. CI BASS -REFLEX ENCLOSURE KIT GLIDELITE FEATURES INCLUDE: Model 7. Adjustable port. Mounting cut- LARGE LENS -5" balance. Magnifier outs for 15 -, 12 -, 81/2-, 8 -inch speakers diameter ground stays put ... both and polished lens. your hands are REFLECTOR SWIV- free! ELS -can be rotat- ARMS ROTATE in ed in a complete full circle around circle, tilted up base. and down. PROPERLY TEN- DOUBLE CLAMP - SIONED SPRIINGS for clamping se- ociedde -provide exact curely. ILLUMINATED MAGNIFIER ... An Ideal Tool for EVERY i GLIDELITE Inspection Requirement! 11 Moonachie Road, Hackensack, New Jersey and most tweeters. 4 -inch birch veneer. Provides ' Please send me the name of my nearest GLIDELITE Installed acoustic damping material. Distortion -Free I distributor and FREE illustrated literature. Fullface grille cloth. 29 x 28 x 16 inches. Magnification -Homewood Industries, 26 Court St., Uniform Glare -Free I NAME Brooklyn, N. Y. Lighting I «45 MAG 22 watt SPEAKER SYSTEMS. TR -30 TRI- with bracket G.E. Circline Available .ADDRESS as shown Tube in Grey ette, complete 3 -way system: 12 -inch e Green to 25 cy- $37.50 3.50 CITY STATE Flexair woofer for response n Il cles; frequency range 20 cycles to be- 102 RADIO -ELECTRONICS

www.americanradiohistory.com 000 cycles. Super tweeter with 40,000 - series. Mounts flush on wall or ceiling. cycle range. Linear flat 28 to 22,000 - 60- 13,000 -cycle response. 8 -ohm voice cycles. 24 x 17 x 121/2 inches. 4 finishes coil. Speaker 6 inches. Overall depth 3 or unfinished. Snap -on frames for en- inches. Dull gold. -Olson Radio Corp., closure to give Swedish Modern, Mod- 260 S. Forge St., Akron, Ohio. ern, Colonial and Italian and French HI -FI KITS. Citation III, profes- Provincial stylings.- University Loud- sional FM tuner (shown): completely speakers, Inc., 80 S. Kensico Ave., White factory- assembled FM cartridge embod- Plains, N. Y. ies most of critical tuner elements; Nu- SPEAKER SYSTEM model SK -181. vistor tube in front end; 2 -stage audio circuit; charcoal brown and gold; wal- yond with crossover points at Specially designed speaker in rear - audibility loaded reflex type enclosure. Response nut enclosure. Citation IV, stereophonic 900 and 6,000 cycles; power rating 30 preamp; separate bass and treble tone watts (60 peak) ; impedance 8 ohms. controls for each channel; do on all GALAXY III (shown), complete stereo heaters; low noise resistors in critical speaker system: bass -center unit and 2 places; 0 to infinity balance control; mil- satellites; 12 -inch Flexair woofer repro- itary type terminal boards; charcoal duces bass up to 350 cycles from both brown and brushed gold; walnut enclo- channels; 2 satellites, each containing sure. Citation V, 80 -watt stereophonic special elliptical speaker for 350- 4,000- power amplifier: 40 rms per channel cycle range and compression tweeter for with 95 -watt peaks; two 7581's per 4,000 cycles to beyond audibility, spaced channel output stage; bias mete-, for from 8 to 20 feet. TF -3, 4- speaker 3 -way system: 10 -inch long -travel Flexair woofer for bass response to 25 cycles; 2 mid -range units take over from 2,000 100 to 12,000 cycles. Impedance 8 ohms, to 10,000 cycles; spherical sector super - rated at 10 watts. Finished in walnut tweeter extends response to beyond au- on four sides. 15%4 x 57/e x 81/4 inches. dibility.- Jensen Mfg. Co., 6601 S. Lara- 6 -foot cable and phone plug.- Lafayette mie Ave., Chicago 38, Ill. Radio Corp., 165 -08 Liberty Ave., Ja- SPEAKER SYSTEM, Medallion XXI. maica 33, N. Y. 3 -way. 12 -inch high -compliance woofer. 8 -inch mid -range speaker for 500 to 3,- SPEAKER model S -394 Thin -Line output tube adjustment; 4 hermeilically .it' sealed silicon diodes and heavy -duty dr. ®. electrolytic power supply; charcoal Am ew ., brown and brushed gold; metal enclo- ® sure.- Harman Kardon, 520 Main St., .. Westbury, N. Y. ---- RECORD PLAYER. Lesa Model SM5 /DU2. 4 speeds. Manual. Stereo - r °'" monaural U -type stereo cartridge. Quick-flip switching. Built -in 45 -rpm (Continued on. page 106) Just Out SUPREME 1961 TV Manual AMAZING BARGAIN COVERS ALL POPULAR SETS The new 1961 TV manual is the Here is your service data for faster, easier bargain of the year. Covers all im- TV repairs. Lowest priced. Best by compari- portant sets of every make in one son. Supreme TV manuals have all needed giant volume. Your price for this service material on every popular TV set. Help- mammoth manual is only $3. This ful, practical, factory -prepared data that will super -value defies all competition. really make TV servicing easy for you. Benefit Other annual volumes at only $3 and save with these amazing values in service each. Factory service material sim- manuals. Only $3 per large, yearly plifies repairs. Includes all data volume. required for quicker TV servicing. 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New edition. Only RADIO VOLUMES SUPREME PUBLICATIONS, 1760 Balsam Rd., Highland Park, ILL RADIO DIAGRAMS 1960 Popular RADIO Rush today TV manuals checked LX bolo," and SUPREME is your best source for all 1959 Diagram Manuals Radio 1958 manuals at left. Satisfaction guaranteed. needed RADIO diagrams and service at only $ data. Covers everything from the most re- 1957 fl 250 New 1961 TV Manual, $3. 1960 TV, $3. cent 1960 radios to pre -war old- timers; 1956 each Additional 1959 TV, $3. Early 1959 TV, $3. home radios, stereo, combinations, transis- 1955 Radio Manual, only $2 1958 TV Manual. $3. Additional 1951 Tr', $3, tor portables, FM, and auto sets. Sensa- 1954 tional values. Only $2 for many volumes. These annual 1953 Early 1957 TV, $3. 1956 TV Ma31r.. . $3. Every manual has extra large schematics, RADIO volumes all needed alignment facts, boards, 1952 Additional 1.955 TV, $3. Early 1955 TV, $3. printed specially priced voltage values, trimmers, dial stringing, rJ 1951 1954 TV, $3. - 1953 TV, $3. 1952 TV, $3. in and helpful hints. Volumes are large 1950 at only $ 250 1951 TV, $3. ,_l 1957 -58 RCA TV Manual, $1.50 size, 81/2x11 inches, about 190 pages. See C 1949 each coupon at right for a complete list of New Television Servicing Course, complere...$3. these popular radio service manuals. 1948 THIS GROUP - 1947 I am enclosing $ Send postpaid. ONLY 1946 I $ El 1942 Send C.O.D. am enclosing .... deposit. 1941 Supreme Pu bu cations 1940 EACH Name: 1926-1938 Manual, $2.50 Sold by All Leading Parts Jobbers Simplified Servicing, $1.50 Address: NOVEMBER, 1960 103

www.americanradiohistory.com Superior', Nev Model 85 -a DYNAMIC type TRANS -CONDUCTANCE TUBE TESTER Employs latest improved TRANS -CONDUCTANCE circuit. Tests tubes under "dynamic" (simulated) operating conditions. An in -phase signal is impressed on the input section of a tube and the resultant plate current change is measured as a function of tube quality. This provides the most suitable method of simulat- ing the manner in which tubes actually operate in radio. TV receivers, amplifiers and other circuits. Am- plification factor, plate resistance and cathode emission are all correlated in one meter reading. SYMBOL REFERENCES: For the first time ever FREE FIVE (5) YEAR CHART DATA SERVICE. in a trans- conductance tube tester Model 85 employs The chart provided with Model 85 includes easy -to- time- saving symbols ( *, -}, , À, l) in place of read listings for over 1,000 modern tube types. Re- difficult -to- remember letters previously used. Re- vised up -to -date subsequent charts will be mailed to peated time studies proved to us that use of these all Model 85 purchasers at no charge for a period scientifically selected symbols speeded up the element of five years after date of purchase. switching step. As the tube manufacturers increase the release of new tube types, this time -saving fea- SPRING RETURN SAFETY SWITCH guards Model 85 against burn -out if tube under test is ture becomes more necessary and advantageous. "shorted." THE "FREE -POINT" LEVER TYPE ELEMENT 7 AND 9 PIN TUBE STRAIGHTENERS have been SWITCH ASSEMBLY marked according to RETMA included on the front panel to eliminate possibility basing, permits application of test voltages to any of of damaging tubes with bent or out -of -line pins. the elements of a tube. The addition of an extra Model 85 -Trans- Conductance Tube Tester. switch position permits the application of the neces- AN ULTRA -SENSITIVE CIRCUIT is used to test Total Price $52.50. Terms: $12.50 after 10 day sary grid voltage needed for dynamic testing and for shorts and leakages up to 5 megohms between all - insures against possible obsolescence due to changes tube elements. trial, then $8.00 monthl for 5 months if sati in basing design. factory. Otherwise return, no explanation Model 85 comes complete, ne:e3ary. NEW IMPROVED TYPE METER with sealed air - housed in a handsome $5250 damping chamber provides accurate. vibrationless portable cabinet with readings. slip -on cover. Only......

N`W '"VACUUM TUBE VOLTMETER WITH NEW 6" FULL -VIEW METER Compare it to any peak -to -peak V.T.V.M. made by any other manufacturer at any price

Model 77 completely wired and calibrated with accessories 77 uses a selenium -rectified power supply resulting (including probe, test leads and portable carrying case) VModelin less heat and thus reducing possibility of damage or sells for only $42.50. value changes of delicate components. Model 77 employs a sensitive six inch meter. Extra large 1a Model 77 meter is virtually burn -out proof. The sensitive meter scale enables us to print all calibrations in large 400 microampere meter is isolated from the measuring cir- easy -to -read type. cuit by a balanced push -pull amplifier. Model 77 uses new improved SICO printed circuitry. Model 77 uses selected l% zero temperature coefficient re- assures unchanging accurate Model 77 a 12AU7 as and two l sistors as multipliers. This employs D.C. amplifier 9006's as peak -to -peak voltage rectifiers to assure maxi- readings on all ranges. mum stability. SPECIFICATIONS volts at 11 AS A DC VOLTMETER: The Model 77 1s Indispensable In DC VOLTS -0 to 3/15/75/150/300 /750/1,500 HI -Pi Amplifier servicing and a must for Black and White inegohins Input resistance. AC VOLTS (RMS) -O to 3/15/75/ and color TV Receiver servicing where circuit loading 150/300/750/1.500 volts. AC VOLTS (Peak to Peak) -O to cannot be tolerated. 8/40/200/400/800 /2.000 volts. ELECTRONIC OHMMETER -0 to 1.000 ohms /10,000 ohms /1ÓO.000 ohms /1 megohm /10 AS AN AC VOLTMETER: Measures HMS values if sine egohms/ 100 megohms/ 1.000 megohms DECIBELS-]O db and peak -to -peak value If Pedestal complex wave. to + 18 db, + 30 db to + 38 db + 30 db to + 58 db. All based voltages that determine the "black" level In TV re- O watts (6 mw) into a 500 ohm line (1.73v). el 77 V.ACl1UM TUBE VOLTMETER ceiversìvers are easily read. on db - .006 - ZERO CENTER METER -For discriminator alignment with full olal Price 842.50-Terms: $12.50 after AS AN ELECTRONIC OHMMETER: Because of its wide le range of to 1.5/7.5/37.5/75 / range of measurement leaky capacitors show up glaringly. O day trial, then monthly 1 50/375/750 volts at 11 megohms $6.00 for 5 Because of its sensitivity and low loading, intermittents input resistance. 50 tths if satisfactory. Otherwise return, are easily found, Isolated and repaired. NET xplanation necessary! Model 77 comes complete with operating instructions, probe and test leads. Use it on the bench- use it on calls. A streamlined carrying case, included at no extra charge, accommodates the tester, r instruction book, probe and leads. Operates on 110.120 volt 60 cycle. Only GENOMETER 7 Signal Generators in One! V R.F. Signal Generator for A.M. V Bar Generator V R.F. Signal Generator for F.M. V Cross Hatch Generator V Audio Frequency Generator V Color Dot Pattern Generator V Marker Generator A versatile all- inclusive GENERATOR which provides ALL the outputs for servicing: A.M. Radio F.M. Radio Amplifiers Black and White TV Color TV R. F. SIGNAL GENERATOR: VARIABLE AUDIO FRE- BAR GENERATOR: The Model TV- The Model TV -50A Genometer QUENCY GENERATOR: In ad- 50A projects an actual Bar Pattern on provides complete coverage for Model TV-50A-Genometer. Total price TV Receiver Screen. Pattern will - A.M. and F.M. alignment. Gen- dition to a fixed 400 cycle any $47.50-Terms: $11.50 after 10 day trial, then erates Radio Frequencies from sine -wave audio, the Model consist of 4 to 16 horizontal bars or $6.00 monthly for 6 months if satisfactory. 100 Kilocycles to 60 Megacycles TV -50A Genometer provides a 7 to 20 vertical bars. on fundamentals and from 60 Otherwise return, no explanation necessary! 300 20,000 TV -50A Megacycles 180 Megacycles variable cycle to THE MODEL to comes absolutely complete s' on powerful harmonics. cycle peak wave audio signal. with shielded leads and instructions. CROSS HATCH GENERATOR: The DOT PATTERN GENERATOR (FOR COLOR TV) MARKER GENERATOR: The Model TV- operating Model TV -50A Genometer will project a Although you will be able to use most of your 50A includes all the most frequently cross -hatch pattern on any TV picture regular standard equipment for servicing Color needed marker points. The following TV, the one addition which is a "must" is a Dot markers are provided: 189 Kc.. 262.5 Kc., tube. The pattern wi Il consist of non - Pattern Generator. The Dot Pattern projected on 456 Kc., 600 Kc., 1000 Kc., 1400 Kc., 1600 shifting, horizontal and vertical lines any color TV Receiver tube by the Model TV- Kc., 2000 Kc., 2500 Kv., 3579 Kv.. 4.5 Mc., interlaced to provide a stable cross- 50A will enable you to adjust for proper color 5 Mc., 10.7 Mc. (3579 Kc. is the color hatch effect. convergence. burst frequency). $47N5E'T in EXAMINE BEFORE YOU BUY! EL imir USE APPROVAL FORM ON NEXT PAGE Imr 104 RADIO -ELECTRONICS

www.americanradiohistory.com The Model 88....A New Combination TRANSISTOR RADIO TESTERa DYNAMIC TRANSISTOR TESTER The Model 88 is perhaps as im- portant a development as was the invention of the transistor itself, TRANS./SI-OR for during the past 5 years, mil- RADIO R lions of transistor radios and other transistor operated devices have MOOELt)H been imported and produced in this country with no adequate pro- _sl±% vision for servicing this ever in- TRANSISTOR aUAUT7 creasing output. reo SRO ATTINUATOR The Model 88 was designed .t,xr PCP 0 specifically to test all transistors, IN amÑ eovçe transistor radios, transistor record- 9 9 ers, and other transistor devices under dynamic conditions.

- AS A TRANSISTOR RADIO TESTER We feel sure all servicemen will agree that the instruments and the receiver by means of a built -in High Gain Transistorized Signal methods previously employed for servicing conventional tube radios Tracer until the cause of trouble whether it be a transistor, some other and TV have proven to be impractical and time consuming when used component or even a break in the printed circuit is located and pin- for transistor radio servicing. The Model 88 provides a new simplified pointed. The injected signal is heard on the front panel speaker as if rapid procedure - a technique developed specifically for transistor is followed through the various stages. Provision has also been made radios and other transistor devices. on the front panel for plugging in a V.O.M. for quantitative measure- An R.F. Signal source, modulated by an audio tone is injected into ment of signal strength. the transistor receiver from the antenna through the R.F. stage, past The Signal Tracing section may also be used less the signal injector the mixer into the I.F. Amplifier and detector stages and on to the for listening to the "quality" of the broadcast signal in the various audio amplifier. This injected signal is then followed and traced through stages.

AS A TRANSISTOR TESTER The Model 88 will test all transistors incuding NPN and PNP, is self- evident. A further benefit of this service is that it will enable silicon, germanium and the new gallium arsinide types, without referring you to test new transistors as they ore released! to characteristic data sheets. The time- saving advantage of this technique SPECIFICATIONS: Model 88 operates on a self- contained 4t /z volt battery and is always Transistor Tester: ready for instant use on the bench or in the field. The transistor tester used in the Model 88 measures the two most im portant transistor characteristics needed for transistor servicing; leakage Signal Injector: and gain (beta). The leakage test measures the emitter current with the base The signal injector used in the Model 88 is o new departure in signal collector- A from 50 ohms to 100,000 ohms source design. Previously, signal sources were provided by signal gen- connection open circuited. range values found in both high and low power erators operating on a single frequency and requiring retuning. The covers all the leakage usually transistor types. Signal Injector of the Model 88 employs a transistor in a grounded emitter self -modulating blocking oscillator generating a low R.F. fre- The gain lest (beta) translates the change in collector current divided quency providing stable harmonics to 30 megacycles. A power output by the base current. Inasmuch as the base current is held to a fixed of over 2.5 volts peak to peak is provided. An altenuator prevents value of 50 micoamperes, the collector current calibrated in relative overload of the receiver or the amplifier under test. gain (beta), is read directly on the meter scale. The Model 88 will test oil transistor types, including NPN or PNP, ger- manium, gallium the newer diffused junction and Signal Tracer: silicon, arsenide and J meso types. Two high -gain grounded emitter transistors are utilized in o high gain Model 88 comes housed in a handsome por- amplifier with sufficient output to operate the built -in 41/2 Alnico V table case. Complete with a set of Clip -On Diode Speaker. A diode is used as a "clamp" to prevent overloading of the Cables for Transistor Testing, an R.F. Probe for R.F. and I.F. Tracing; on Audio Probe output stage. A volume control permits attenuation of strong signals. for Amplifier Tracing and a Signal Injector Ca- Provision is also made on the front panel for the addition of a meter ble. Complete -nothing else to buy! or an oscilloscope for quantitative evaluation of the signal strength. Only _. SHIPPED ON APPROVAL NO MONEY WITH ORDER -NO C O. D. k fry any of the instru- ments on this or the MOSS ELECTRONIC, INC. facing page for 10 Dept. D -820 3849 Tenth Ave., New York 34, N.Y. days before you buy. l'lease send me the units checked on approval. If completely satisfied I will pay on Name _._.. -. If completely satisfied the terms specified with no interest or finance charges added. Otherwise, I will return then send down pay- after a 10 day trial positively cancelling all further obligations. I ment and pay bal- Model 85 Total Price $52.50 Model 77 Total Price 542.50 ance as indicated on 512.50 within 10 days. Balance $8.00 $12.50 within 10 days. Balance $6.00 Address _._ -. -.. coupon. No Interest monthly for 5 months. monthly for 5 months. or Finance Charrges 1 rdded! If not com- Model TV-50A Total Price 547.50 Model 88 Total Price $38.50 p ete y satisfied re- 511.50 within 10 days. Balance $6.00 58.50 within 10 days. Balance 56.00 City Zone State.___._.__- turn unit to us, no monthly for 6 months. monthly for 5 months. All prices net. F.O.B., N. Y. C. explanation neces- Export Division: Rocke International Corp., 13 East 40th St.. New York 18, N.Y. sary.

NOVEMBER, I 960 105

www.americanradiohistory.com (Continued from page 103) BIG, BIG SAVINGS on PARTS from Tee Vee Supply TINY CAPACITOR KIT 51.89 SPRING KIT NEEDED CONDENSER KIT NOW! $1.49 $1.69 H. 50 assorted tiny 200 piece spring 25 postage stamp capacitors in a assortment consists mica compression variety of mfds of 8 different trimmers voltages many and ideal types of springs with brackets. The for small elec- including compres- 25 different con- Ironic assemblies sion and expan- densers in this kit ., such as transistor sion types com- represent a wide range of sets or other applications. Con. monly used in TV, radio and capacities from 3 to 280 MMFD. sists of 35 tiny insulated paper phonographs. Shipped in a Packaged in a clear plastic bag. capacitors and 15 ceramic capac- really useful heavy duty plastic Wt.: 8 oz. 2 itors. All mfds clearly printed box with hinged lid. Wt.: 8 oz. spindle. -tone colors. -Electrophone & on each. Wt.: 3 oz. TV COIL KIT Parts Corp., 530 Canal St., New York $1.69 13, N. Y. CROSSOVER CONDENSER KIT 21 MC. TV I.F. KIT 99C 25 5 CROSSOVER 10-21 MC. TV I.F.S. assorted TV COND. $1.89 coils for re- TURNTABLE Empire 208. Hystere- Heres on amazing the 5 non -polarized - pair shop or lab. sis synchronous motor. Belt coupling. value!! 10 stand- capacitors ideal Contains peaking and type 21 to 26 Variable 3 -speed adjustment. Pushbut- for coupling the coils. IF's, width ws tweeter to the megacycle I.F.s ton power control. 6 -lb. table with and ratio detector in woofer speakers - include a lib- coils a double -rim flywheel design. Cushioned it C plastic bag. The anyone of 3ï ii eral variety of use of one or two coifs will more than pay which the shielded and un. can do . for the entire kit. Priced li ; - real job, ranging from q shielded types . . All are low! Wt.: 8 oz. .5 mfd to 10 mfd and priced so replaced by popular Stancor- low, that one capacitor only Merti numbers. Use just one would cost more than the kit. and it pays for the entire kit. VERTICAL MOUNT You will be pleased. Order now Order now at great savings ... CAPACITORS WI.: 4 oz. Wt.. 12 oz. All Popular Values TAB MOUNT CONTROLS $1.99 DUAL CONCENTRIC 20 Vertical 10 tab mount vol- CONTROLS Capacitors ume controls. Hard $3.29 51.69 to get items, not normally available 10 assorted dual Here is an assortment of plas- rí in distributor concentric controls tic cased vertical mount tubu- stocks!! Kit in- used in TV and lars for all printed circuit cludes a wide auto radio. Kit chassis today. A wide variety range of ohmages used in radio includes 5 each of mfds to meet most demands, phono, and TV work. All con- controls with and ranging from .00 to .1 Twenty vertical thrust support. Acoustically iso- trols are designed for direct without switch. all pocked in clear plastic bags. lated motor suspension. Satin chrome or mount to the chassis. These are All were made for very large This is a must for all service- the most commonly used con- TV and auto radio mfgs . . men and experimenters today. gold Swiss finish.-Dyna-Em pire, Inc., trols in modern design automa- Wt.: I Ib. Order now at great Order now at our low price! 1075 Stewart Ave., Garden City, N. Y. tion and printed work. savings! Wt.: 6 circuit oz. DISC RECORDER, Imperial II. Cuts 20 METAL CLAD RESISTORS 100 ASS'T INSULATED $2.89 HUGE HARDWARE ASS'T 6- to 131/4 -inch master records at S1.89 RESISTORS $1.49 331/3 and 78 rpm. Idler and adapter for 100 Top quality mot always popu- 45 rpm. Recording -head response 30 to clad resistorsresi storrs lar value t /z, 1 and 2 waft insu- King size 2 lb . sometimes called assortment candohms. A wide lated carbon re- in- 411...jabis, cludes hard range of resistance sistors. Every to get nuts, screws, values and lengths resistor standard RMA color bolts, bushings, etc., in from 2t/2" to 9 ". l' coded and made by standard manufacturer. a strong plastic Dissipate heat rapidly when Kit includes 70 -1/2, 20 -I, and 10 -2 watt resistors. iar... All shops mounted to metal chassis Wt. : Ideal for labs, TV and radio want this . . . 2 lbs servicemen. Packed in a clear plastic bag. Wt.: 6 oz.

Send 25 °/e deposit with order, balance C.O.D. plus postage. Freight prepaid on orders of $50.00 or more. SEND FOR COMPLETE CATALOGS OF KITS. TEE -VEE SUPPLY CO. 3211 Washington St., Jamaica Plain 30, Mass.

13,000 cycles. Recording and playback Please mention amplifier 20 -watt output and 20- 20,000- cycle response. - Rek -O -Kut Company, Inc., 38-19 108 St., Corona 68, N. Y. TAPE RECORDER, RCA MI- 35120. RADIO -ELECTRONICS 7%, 33/4 and 17/a ips. Operates from 117 volts, 60 cycles. 7 -inch reel holds 1,200 when answering advertisements

FREE Catalog OF SURPLUS ELECTRONIC BARGAINS feet standard 14-inch tape recording on UNIVERSITY 25 WATT half tape's width. 2 built -in speakers DRIVER UNIT with output jack for external speaker. 25 - 81/2 x 14% x 16 inches. Charcoal gray Delivers Watt High volume low distortion output. Excellent reproduction for nussie and speech. Frequency range 90 to 9000 grained fabric. RCA, 30 Rockefeller cycles. 15 ohm impedance matches all amplifiers. Standard 24 thread - x 1%" mounting nipple fits all trumpets and projectors. Size: Plaza, New York 20, N. Y. 5 x 41/2". wt.: -I His, University No. S.A -30I1-Gov't # 11x -1051 At. Our Low l'rirr ool TONE ARM complete with crystal Address Dept. RE All Prices F.O.B., Lima, Ohio $5.95 25°/e Deposit Required on C.O.D. Orders stereo cartridge Ti Series. Plastic with plated finger lift. Compression -type or SEND NOW FOR solid rear mounting post. Wired from BIG FREE FAIR RADIO SALES cartridge plug through arm with ap- CATALOG! 2133 ELIDA RD. P.O. Box 1105 LIMA, OHIO proximately 13 inches additional wire 106 RADIO -ELECTRONICS

www.americanradiohistory.com ADDARTHUR GODFREY TO YOUR SALES STAFF

WITHOUT ADDING HIM TO YOUR PAYROLL!

Tie in locally with the national Sylvania Silver Screen 85 TV 'Tube promotion featuring you, the independent service dealer Arthur Godfrey, America's Number One Salesman, is selling - the Sylvania Silver Screen 85 TV picture tube -and Sylvania quality small tubes -in a dynamic national advertising campaign. Just look where you're being promoted ... twice each week on 200 CBS Radio Network stations

across the country . The Saturda Eve- ning Post . and lots more!

cLtlwrGoáfrey To make the most of this sales -getting STOP promotion, be sure you use all the local HERE tie -in aids Sylvania now offers: QUALITY GIANT WINDOW DISPLAY -colorful, 3- dimensional . features you and Arthur l sERVICE Godfrey, (Order #1139) 3 -PIECE DECAL KIT -Sparkling glassine SILVER SCREEN 85._ w aaaho "r .- tiYlt'071A --O- signs with Arthur Godfrey saying. "Stop Here For Quality TV Service." (Order #1138) GIANT WINDOW POSTER -Big 20 "x 26" SYRNIK> poster promotes your service. (Order #2095) LIVEN To ARTHUR Each and every promotion piece is designed MAU TIME to help you sell Sylvania Silver Screen 85 NOWT THROUGH TV tubes plus Sylvania quality small tubes. INDAY ce THE For your supply -and helpful hints on how as RAN) NETWORK to make the best use of these selling aids - contact your Sylvania distributor. Do it today!

Electronic Tubes Division, Sylvania Electric Products Inc., 1740 Broadway, New York 19, New York

SYLVAN GENERAD Subsiorivy of GENERAL TELEPHONE & ELECTRON/Cs NOVEMBER, 1960 107

www.americanradiohistory.com from end of mounting post. High- or low- output voltage cartridges. Turnover lever snaps out for replacement. Brown or gray. - Sonotone Corp., Elmsford, N. Y. FM ANTENNA, Lark. S -type all -di- rection design. Available as individual antenna or complete kit. Golden ano- dized.- Technical Appliance Corp. (TA- Just because 2 speakers LOOK alike CO), Sherburne, N. Y. UHF ANTENNAS. TR604, 4 -bay for primary uhf translator locations; TR- 606, 6 -bay for near -fringe uhf ; TR612 (shown), 12 -bay for fringe and far - fringe. For improved broad -band re- doesn't sponse on channels 70 -83. Highly rigid, mean heavy -gauge, galvanized, welded wire they'll SOUND alike... or that they'll give the rod construction. Oversized precision - formed cardioid dipoles of corrosion - same proof solid aluminum rod. Half -wave horizontal and vertical spacing of bays. trouble -free Solid busbar multistage phasing trans- formers for constant 300 -ohm imped- performance. ance over uhf translator spectrum. - JFD Electronics Corp., 6101 16th Ave., Brooklyn 4, N. Y. BOOSTERS, TV and FM. DSA -202 preamp (shown): remote power supply; mast- mounted; 2 tubes; 51/2 lbs, 81/2 x ask for (1.6 61/4 x 4 inches; iridite- finished alumi- UAM

The NO CALL-BACK speaker with the exclusive Adjust -a -Cone Suspension Completely manufactured in the United States of America num case. HSA -43: 3 -set coupler; single tube; special circuitry; 41/2 x 41/2 x 3 inches; die -cast case; brown and beige finish.-Jerrold Electronics Corp., 15th QUAM -NICHOLS COMPANY and Lehigh Aves., Philadelphia 32, Pa. 238 East Marquette Road Chicago 37, Illinois TRANSCEIVER TRC -27 for Citizens band. Meets FCC requirements. Corn - wired, to 117 vac TUBE TESTER INTO A HIGHLY pletely ready operate. ANOTHER CONVERT YOUR and 12 vdc transistorized power sup- EFFICIENT PICTURE TUBE TESTER ... plies, positive or negative ground. 10 tubes, 5 with dual stages. Electronic /77/eìzecuzqJ No other CRT Adopter does os much as the MULTI -HEAD! SERVICE AID v< TEST ALL BLACK AND WHITE PICTURE TUBES

vo TEST ALL switching. Crystal -controlled transmit- The MULTI -HEAD incorporates: COLOR ter and receiver each with 22 possible 12 -pin socket -for all standard base black and white tubes channels. 41/2 -inch PM speaker. Push -to- 8 -pin socket -for all 110 degree narrow -neck RCA type tubes PICTURE TUBES 7 -pin socket -for all 110 degree narrow -neck Philco and Sylvania type tubes talk dynamic microphone. Light gray 14 -pin socket -for all color TV tubes in use today A enamel finish, 5 x 13 x 7 inches. -Radio Color gun switch -for checking the red, green and blue color guns separately Model MH-1 ny s MULTI -HEAD Net Shack Corp., 730 Commonwealth Ave., See your electronics parts distributor Boston 17, Mass. SEARING AVENUE, NEW YORK MERCURY ELECTRONICS CORP Office: 4306 W. Victory/ B vo; Burbank.u Calif. CONTACT CLEANER, Formula BC-

108 RADIO -ELECTRONICS

www.americanradiohistory.com is and portable equipment. ST -25 (not shown), single- contact type for micro- phones, amplifiers, transmitters, tape

44. Lubricates and conditions. 6 -oz push- 41i O button spray can with 5 -inch plastic ex- recorders, headphones. - Switchcraft, tender.- Electronic Chemical Corp., 813 Inc., 5555 N. Elston Ave., Chicago 30, 10 -10 has identical dc vertical, horizon- Communipaw Ave., Jersey City 4, N. J. Ill. tal amplifiers. 3 -inch CRT. Bandwidth ILLUMINATED MAGNIFIER. 5- DUAL PURPOSE TEST INSTRU- dc to 200,000 cycles (2 -db point). Sen- inch- diameter 4- power magnification MENT model 400. 20,000- ohms -per -volt sitivity 0.1 volt (peak to peak) per ?4 ground and polished lens surrounded by vom and capacitance meter. Slope front inch. 3- position attenuator, continu- ously variable gain control. Multivibra- tor type sweep generator cover 5 to 50,000 cycles in 4 ranges. Low relative phase shift between channels.-Heath Co., Benton Harbor Mich. CAPACITORS MLE (shown) sub- miniature electrolytics. Temperature range -40 °C to +85 °C for critical cir- cuits. CQM, electrolytic in hermetically sealed aluminum container to operate at

22 -watt circular fluorescent tube. Re- flector swivels for rotating in complete -20 °C to +65 °C; TAK -H, wet electro- circle or Lp and down tilting. -Glidelite, projects 41/2 -inch meter forward. 3 lyte tantalum meeting specifications 11 Moonachie Rd., Hackensack, N. J. knobs and 3 jacks. Wide range of oper- MIL -C -3965; TAD, solid tantalum in CONNECTORS. Molded cable assem- ation. - Mercury Electronics Corp., 77 varied sizes and values hermetically blies. Y -type junction ST -90 for head- Searing Ave., Mineola, N. Y. sealed for -40 °C to +85 °C. 125 °C phones, binaural and stereophonic head- OSCILLOSCOPE KIT for general - range -Pyramid Electric Co., 1.145 Hud- sets. ST -26, 4- contact type for electron- purpose, medical, industrial use. Model son Blvd., N. Bergen, N. J. END All specifications on these pages are from manufacturer's data.

Replace improper equipment with the only microphone designed specifically THE for citizen's band

This reasonably priced, mobile -type ceramic microphone is the perfect replacement for the many imprope-, tape recorder -type microphones now being used on CB equipment. Has DPST switch wired for relay operation with eas ly reversible terminals to allow modifications (if necessar),); wiring diagram enclosed with each microphone; hanger button and standard dash bracket for mobile rig mounting; and an 11" retracted (five foot extended), plastic - jacketed, coiled cord. Response: 80 -7,000 cps. Output: -54 db. List price: $16.80 complete. See THE MICROPFONE COM'ANY your Turner Distributor, listed 933 7th St. N.E. below, he has the 350C in stock. Cedcr Rapids, low

ARKANSAS Bloomington: Stansifer Radio Co. MASSACHUSETTS Columbus: Whitehead Radio Cc -party Little Rock: Southern Radio Supply Evansville: Hutch and Son, Inc. Boston: A. W. Mayer Company Mansfield: Wholesaling, Inc. Texarkana: Lavender Radio & T.V. Sup. Ohio Valley Sound Radio Shack Corp. Toledo: Lifetime Electronics CALIFORNIA Fort Wayne: Pembleton Laboratories Lawrence: AIco.Electronics OKLAHOMA Downey: Net Electronics Indianapolis: Brown Distributing Co. MICHIGAN Oklahoma City: Johnson Whcleto'e Hemet: Gil Severns Graham Electronic Sup. Ann Arbor: Purchase Radio Supply Hollywood: Pacific Radio Exchange Van Sickle Radio Supply Detroit: High Fidelity Workshop OREGON Los Angeles: Radio Product Sales Kokomo: George's Electronic Sup. Lansing: Offenhauer Company Portland: United Radio Supply The Sound Foyer Michigan City: Tri -State Electrical Sup. MINNESOTA PENNSYLVANIA Oakland: Elmar Electronics Portland: Buck's Hi -Fi Minneapolis: Schack Electronics Lancaster: George D. Barbey Co, Sacramento: Selectronics Richmond: Fox Electronics Company MISSOURI Lebanon: George D. Barbey Co. San Francisco: Market Radio Sound Dept. Terre Haute: Midwest Supply Company St. Louis: Radonics Philadelphia: Radio Electric Sern;ce Co. San Pedro: Marine Radio Service IOWA NEW JERSEY Pottstown: George D. Barbey C DISTRICT OF COLUMBIA Cedar Rapids: Iowa Radio Supp'y Berlin: Midstote Radio Supply Reading: George D. Barbey Co. Washington: Electronic Wholesalers Jersey Des Moines: Radio Trade Supply Co. City: Nidisco- Jersey City Wilkes- Barre: General Radio & G.ectrcnic FLORIDA Mountainside: Federated Purchaser KANSAS York: Radio Electric Service Co. Miami: East Coast Rodio & TV NEW YORK Tampa: Kinkade Topeka: Acme Radio Supply TEXAS Radio Supply Buffalo: Radio Equipment Corp. Houston: Sound Equipment Inc. GEORGIA KENTUCKY Farmingdale, L.I.: Gem Electronics VIRGINIA Atlanta: Specialty Distributing Lexington: Radio Equipment Co. Forest Hills: Beam Electronics ILLINOIS Louisville: Arcby Electronics Mt. Vernon: Davis Electronics Arlington: Rucker Electronic Products Chicago: Nationwide Radio P. I. Burks Company New York: Harvey Radio Company Falls Church: The Television Wcrkshcp La Salle: La Salle Electronics LOUISIANA Acme Electronics WISCONSIN INDIANA Baton Rouge: Davis Electronics Sup. OHIO Chippewa Falls: Bushland Radio Anderson: Scec. Seybert's Radio Sup. New Iberia: Brooks Electronics Cleveland: Pioneer Electronic Sup. Eau Claire: Bushlland Radio Spec. NOVEMBER, 1960 109

www.americanradiohistory.com BECOME A RADIO TECHNICIAN for only $26.95 BUILD 20 RADIO AT HOME CIRCUITS Reg. U.S. with Ohe New Progressive Pat. Off. RADIO "EDU- KIT All Guaranteed to Work! PRINTED CIRCUIT GROUNDS PRACTICAL only The ground circuit of a printed- circuit board should connect to the main chassis securely, adequately and per- HOME $ 95 manently at all ground points. Some circuits will perform RADIO 26 with only one such ground, but many printed boards carry COURSE high -frequency signals and the loss of a ground may cause instability and other undesired effects. NOW INCLUDES When renewing a board, or replacing the ground screws * 12 RECEIVERS TRAINING ELECTRONICS after service, put a small star washer under each screw. TECHNICIANS SINCE 1946 * 3 TRANSMITTERS Tighten securely enough so the teeth of the washer bite SQ. WAVE GENERATOR * No Knowledge of Radio * Necessary into the plating, but not enough to tear or break it. A solder * AMPLIFIER * No Additional Parts or job too and provides a * SIGNAL TRACER Tools needed lug with shakeproof teeth does the * Excellent Background for TV to the future, * SIGNAL INJECTOR * School Inquiries Invited handy place clip a vtvm ground lead in - * CODE OSCILLATOR * Attractively Gift Packed Lawrence Shaw FREE EXTRAS SET OF TOOLS RADIO & ELECTRONICS TESTER ELECTRIC USING SINE WAVES SOLDERING IRON TESTER INSTRUCTION MANUAL MEMBER- SHIP IN RADIO -TV CLUB: CONSULTATION SERVICE HI -FI GUIDE A sine wave, viewed on a scope, will reveal certain types QUIZZES TV BOOK FCC AMATEUR LICENSE TRAINING of distortion. (The diagram shows the appearance of a RADIO BOOK PRINTED CIRCUITRY PLIERS -CUTTERS ALIGNMENT TOOL WRENCH SET CERTIFICATE OF MERIT sine wave, before and after harmonic distortion.) The sine VALUABLE DISCOUNT CARD wave at the output of an amplifier should look just like the WHAT THE "EDU -KIT" OFFERS YOU sine wave applied to the input. A sine -wave check will The Etlu -Kit" offers you an outstanding PRACTICAL HOME RADIO COURSE at a rock- bottom price. Our kit is designed to train Radio 6 Electronics Technicians. also show overall amplifier gain or stage gain or loss. making use of the most modern methods of home training. You will learn radio theory, construction, servicing, basic Hi -Fi and TV repairs, code. FCC amateur license requirements. You will learn how to identify radio symbols, how to read and interpret sche- matics, how to mount and lay out radio parts, how to wire and solder, how to operate electronic equipment. how to build radios. Today it is n o longer necessary to spend hundreds of dollars fora radio course. You will a basic education in radio, worth many times the small price you pay. only $26.95 complete. THE KIT FOR EVERYONE The Progressive Radio 'Edu -Kit" was specifically prepared for any person who has a desire to learn Radio. The "Edu -Kit' has been used cessfully by young and old in all parts of the world, by many Radio Schools dClubss in this country and abroad. It i used for training and rehabilitar on of Armed Forces Personnel and Veterans throughout the world. AFTER The Progressive Radio 'Edu -Kit" requires no instructor. All instructions are BEFORE included. Every step is carefully explained. You cannot make a mistake. PROGRESSIVE TEACHING METHOD A sine -wave test will not show up frequency distortion The Progressive Radio "Edu -Kit" is the foremost educational radio kit in the world, and is universally a cepted as the standard in the field of electronics training: (loss of highs or lows) since only one particular frequency The 'Edu -Kit' the ' modern educational principle of "Learn by Doing. Therefore, you willeconconstruct radio circuits, perform jobs and conduct experiments is amplified at a time (use square waves if you are looking to illustrate the principles which you learn. You begin by examining the various radio parts included in the "Edu- Nit." You for loss of high or low frequencies). IM distortion also will then learn the function, theory and wiring of these parts. Then you build a simple radio. With this first set, you will enjoy listening to regular broadcast stations, learn theory, practice testing and troubleshooting. Then you build a more ad- not show up since it is produced by the hetrodyning of two vanced radio, learn advanced theory and techniques. Gradually, in a pro- gressive manner, and at e your own rate- you will find yourself constructing more or more frequencies and cannot be detected by using a advanced multi -tube radio circuits. and doing work like a professional Radio Technician. single -tone sine wave. -W. C. Warren Included in the "Edu -Kit" course are twenty Receiver, Transmitter, Code Oscil- lator, Signal Tracer, Signal Injector, Square Wave Generator and Amplifier circuits. These are not unprofessional "breadboard" experiments, but genuine radio circuits, constructed by means of professional wiring and soldering on metal chassis, plus the new method of radio construction known as "Printed Circuitry.' These circuits SNIVET INTERFERENCE operate on ycur regular AC or DC house current. In order to provide a thorough, well-integrated and easily -learned radio course. Occasionally, dark irregular lines may be seen on the the "Edu -Kit" includes practical work as 11 as theory; troubleshooting in addi- tion to on tre; training for all, whether your purpose in learning radio be for hobby, business or job; progressively -arranged m terial, ranging from simple right side of the television picture in weak and moderate circuits to well -advanced topics in Hi -Fi and TV. Your studies will be further aided by Quiz materials and our well -known FREE Consultation Service. signal areas. This trouble (snivets) originates in the hori- THE "EDU -KIT" IS COMPLETE by very rapid change of You will receive all parts and instructions necessary to build 20 different dio zontal output tube and is caused a and electronics circuits, each guaranteed to operate. Our Kits contain tubes, r tube sockets, variable, electrolytic, mica,m ceramic and paper dielectric condensers, resis- plate and screen current when the tube operates near the tors, tie strips, coils, hardware, tubing punched metal chassis, Instruction Man- uals, hookup wire, solder, selenium rectifiers. volume controls, switches, knobs, etc. knee of its plate characteristic. The sudden change of plate In addition, you Printed Circuit materials, including Printed Circuit chas- re a us ful s t sis, pecial tube sockets, hardware and instructions. You also receive and screen current may cause rf radiation which often of ttools. a professional electric soldering iron, and elf -powered [Dynamic Radio E. Electronics Tester. The "Edu-Kit" also includes Code Instructions and the Pro- appears on low- or high -band vhf or uhf channels. gressive Code Oscillator, in addition to the F.C.C. -type Questions and Answers for Radio Amateur License training. You will also receive lessons for servicing with To reduce this interference, dressing the he Progressive Signal Tracer and the Progressive Signal Injector, and a High kind of try Fidelity Guide d Quiz Book. Everything is yours to keep. line from deflection If this doesn't J. Statatis, of25 Poplar PI., Waterbury, Conn., writes: 'I have repaired severa antenna away the circuit. ets for my friends. and made money. The "Edu -Kit" paid for itself. I was ready o spend 5240 for a Course, but I found your ad and sent for your Kit." work, try making small adjustments of width, linearity and oper- UNCONDITIONAL MONEY -BACK GUARANTEE horizontal drive. These adjustments may change the The Progressive Radio 'Edu -Kit" has been sold to many thousands of indi- ating condition causing the snivets. The third thing to do is viduals, schools and organizations, public and private. throughout the world. It is recognized internationally as the ideal radio course. replace the horizontal output tube. You may have to try By popular demand the Progressive Radio "Edu -Kit" is now available in Spanish as well as English. more than one replacement before finding one that will It is understood and agreed that should the Progressive Radio "Edu -Kit" be returned to Progressive Edu- Kits" Inc.. for any reason whatever. the pur- the trouble. The tube can be used in stronger chase price will be refunded in full, without quibble or question, and without eliminate "bad" delay. The high recognition which Progressive "Edu- Kits" Inc. has earned through signal areas or sometimes in another TV receiver without its many years of service to the public is due to its unconditional insistence upon the maintenance of perfect engineering, the highest instructional stand- causing any trouble. -M. L. Leonard ards, and 1000/o adherence to its Unconditional Money -Back Guarantee. As result, we do not have a single dissatisfied customer throughout the entire world. SYLVANIA CHASSIS 1 -544 -1 ORDER FROM AD- RECEIVE FREE BONUS RESISTOR AND CONDENSER KITS WORTH S7.00 The complaint was vertical FROM VIDEO 23CP4 Send Edu -Kit" Postpaid. I enclose full payment of 526.95. compression, but of a rather OUTPUT 7 l Ill PIX Send "Edu -Kit" C.O.D. I will pay 526.95 plus postage. Send me FREE additional information describing "Etlu- Kit." unusual type. The compression 2 Name was only in white areas. Directly below this area, the /Thi, GREEN LEAD ADD scanning lines were spread. K BREAK A check of Sylvania service .5W 1 186 Broadway, Dept. 170G Progressive "EDU- KITS" Inc. Hewlett, N. Y. data in our files revealed that ELECTRONICS 110 RADIO-

www.americanradiohistory.com this trouble is often caused by grid current in the picture tube (the video signal drives the picture tube's cathode negative with respect to the grid). This grid current dis- rupts the waveshaping accomplished in the vertical retrace BUY PYRAMID. plate and causes a notch in the waveshape at the grid of the vertical oscillator. A quick field repair called for inserting a 22,000 -ohm resistor between the picture tube grid and the lead now connected to the picture tube. The resistor isolates GET MORE the picture tube grid.- Warren Roy

NO SOUND Only Pyramid offers you so much! Only If a transistor auto radio is dead (no sound) and the Pyramid gives you highest quality ca- power transistor is cold, check the transistor very carefully. pacitors plus so many "all new" extras. Beware of hasty diagnosis. Before ordering another tran- sistor, make a careful ohmmeter test of the output trans-

AUDIO OUTPUT THE VU -PAK An entirely new way to package OUTPUT TRANS capacitors ... DRIVER clear plastic tubes, plainly labeled and packed TRANS with the highest quality electrolytic twist -mount FROM capacitors. Each re- usable Vu -Pak comes with DRIVER III a blank label, ideal for storing small parts and SPKR tools on your bench or in your tool kit. Bt

2 HEAVY WIRES PULLED OUT TO BIAS FORM TAP. COLD SOLDER JOINT former, especially if it is an autotransformer type. The EXTRA OFFER! transformer tap may be open because of an imperfect solder joint, causing the same symptoms Save 50 Vu -Pak labels and get the as a defective transistor! fabulous new Pyramid This defect can usually be storage repaired. Carefully slit the paper rack the Capac covering the transformer to -o -mat, at tre- expose the leads. Then clean mendous savings from and resolder, coat with insulating compound and retape. your -Jack Darr authorized Pyramid distributor. The Capac -o -mat fits right on your shel, is dust -free and holds MAGNAVOX 105 SERIES 54 Vu -Paks. The complaint was that, about once a week, the picture would fall into some peculiar behavior sounding to us like a piecrust or multiple- triggering condition. We replaced the horizontal sweep tubes and after a short air test told the JEWEL BOX Handsome tan plastic, high impact customer to let us know cabinet if there was any further trouble. with 9 drawers, contains 45 assorted Mylar'- We were back again 4 days later and this time were lucky paper Gold Dip capacitors, type 151. Practical enough to have the set act up while we were there. Sure ... convenient ... fot_storage in your shop, or enough, it looked like multiple triggering since each scanning home. Actual value of the Jewel Box with 45 line was displaced from its sidekicks. We also discovered Gold Dip capacitors -$19.50, dealer net only that, each time the trouble cleared up, we could make it $9.25. recur by turning the brightness control way down. From this we deduced that the offending component must Gold Dip capacitors are also available in Clear - be directly associated with the high voltage since varying Vu paks ... 5 to a package. Find them on the brightness does affect the current flow through the Pyramid's new Whirl -o -mat on your favorite second -anode supply source. A new 1B3 did not help and parts distributor counter. neither did a high -voltage capacitor and limiting resistor. We pulled the set and installed a new flyback transformer. Although we had never seen a flyback behave in this manner "GOLD S'ANIIARD" 111 KIT before, it seemed like a logical hunch -and it paid off. The Clear lucite hinged box containing old transformer was evidently setting up its own parasitic 75 Pyramid's popular assorted oscillations, giving all the symptoms of a defective afc cir- Gold Stancard Mylar' capacitors. r cuit. Frank A. Salerno You'll find so many uses for the Gold Standard 111 Kit. Actual MOTOROLA CAR RADIO 78MF value is $26.0C, dealer net only The trouble was a loud squeal no matter how the volume $13.00. control was set. A check of this receiver revealed an open THIS CAP OPENED 515 LYTIK -KIT TO Hinged cover, clear lucite box with DR VER + 500µf OUTPUT 15 assorted miniature low voltage TRANS TRANS I2K5 electrolytic capacitors for transistor- DRIVER ized circuit replacements. type 2N176(2) IWLV. This Kit is a constant rom - PWR AMPL panion to any busy serviceman. Actual value, $20.60, dealer net only $10.30.

TO .500µf OUTPUT TRANS ELECTRIC PYRAMID COMPANY 500-µf electrolytic in the transistor power output stage. DISTRIBUTOR DIVISION: UNION CITY, NEW JERSEY The solution was to replace the open electrolytic with a Factories: Gastonia, North Carolina Darlington, South Carolina In Canada: Wm. Cohen, Limited, 8900 Tanguay new one.-M. L. Leonard END Street, Montreal Export: Mlorhan Exporting Co., 485 Broadway, New York 13. N. Y. NOVEMBER, 1960 111

www.americanradiohistory.com TECHNICIANS'

r 'My Photofact Library is the most important NE tool in my daily servicing. With my Photofacts I am able to complete a job in just half the time it would take without them NATESA ANNUAL CONVENTION ...Membership in the PEET pro- The National Alliance of Television gram is the best thing that could & Electronic Service Associations met happen to any Electronic Tech- in Chicago, Aug. 19 -21. Those attending represented 98 affiliated cities and total nician. I believe I speak from attendance showed a 30% increase over experience as this is my 19th last year. year of full -time servicing." Following a closed council meeting -A. Kish, Jr. the day before, the convention officially the morning of Aug. 19. Morris Al's Radio & Television opened Finneburgh, vice president in charge Carteret, N. J. of public relations at the Finney Antenna Co., was keynote speaker dur- ing the convention and delivered, according to TESA News, "a most inspirational talk . the kind where you can hear a pin drop in the room." Service Technicians! YOU EARN MORE... An important part of the convention was the election of officers. Alphonse YOU RATE when you own A. Benoit from New Orleans became with the public the new NATESA president. He suc- ceeds Mac Metoyer. the PHOTOFACTu data Other officers elected were: Wally service library! Hirschberg, St. Louis, secretary gen- eral; Nelson Burns, Memphis, re- elected You enjoy maximum earnings as the HOW TO STAY AHEAD... treasurer; Irving Toner, Eastern vice owner of a complete PHOTOFACT Yes, the truly successful Service president; T. R. Nabors, East Central Service Data Library! It's inevitable, Technicians are those who own vice president; John Graham, East because no matter how expert you are, thecomplete PHOTOFACT Library, Central secretary; Harry Eales, West you can always save more time on who can meet and solve any re- Central vice president; Ralph Woerten- dyke, secretary; Winston any job, get more jobs done daily pair problem- faster and more West Central - profitably. And these men keep Haines, Western vice president, and EARN MORE, DAY IN AND DAY OUT... ahead because they're on a Stand- Jim Humphrey, Western secretary. What's more -as the owner of a ing Order Subscription with their QUERY SERVICE RATES complete PHOTOFACT Library, you Distributors to receive all new In an attempt to aid its members in know your customers' sets best. You PHOTO FACTS as they are released charging proper, reasonable rates for can actually show each customer you monthly. (They're eligible for the service work, the Tri -State Council of have the PHOTOFACT Folder covering benefits of membership in PEET, Television Service Associations will too -see below!) its mem- his very own set. Result: You command circulate questionnaires among bers in New Jersey, Delaware and public which ONLY $10 DOWN puts the com- respect and acceptance plete PHOTOFACT Library in your Pennsylvania asking for information paves the way to more business and shop -and you have up to 30 months on business problems. The association earnings for you. to pay. See your Sams Distributor stresses that there will be no price today, or write to fixing. Howard W. Sams The results of the survey will be used only to assist members who are not charging enough or who are charg- NOW IS THE TIME TO JOIN ing too much.

r- - - THE POWERFUL NEW PROGRAM SERVICE CALL HOWARD W. SAMS & CO., INC. FOR QUALIFIED TECHNICIANS TSA Service News states that many 1726E. 38th St., Indianapolis 6, Ind. a If you now own a PHOTO - technicians have been asking for FACT Library or plan to own Send me full details on the new "PEET" Program. definition of a service call. They use one, you can apply for mem- Send full information on the Easy -Buy Plan and Free the following definition adopted by bership in "PEET." It's the File Cabinet deal. NATE SA : first industry program really "Service Call: Consisting of travel interested in a Standing Order Subscription. designed to build powerful I'm time to the home, the inspection and /or public acceptance for the I'm a Service Technician full -time; part -time testing of circuit tubes, and minor Service Technician who qual- with a 30-minute time ifies. Builds enviable prestige My distributor is adjustments, and business for its members. limit and no chassis pull. Beyond the Benefits cost you absolutely Shop Name 30- minute time limit, regular hourly nothing if you qualify. Ask rates apply." your Sams Distributor for the Attn: "PEET" details, or mail cou- TUBE WARRANTIES Address pon today. R. M. Andrews, assistant district City Zone State sales manager for Tung -Sol, recom- L J mended discontinuing receiving tube 112 RADIO -ELECTRONICS

www.americanradiohistory.com warranties and reducing the retail price and point it out to each customer in a of the tubes some 30% at the NATESA case such as this. Better yet, deliver convention in Chicago. He backed his to the customer a claim check on which IMPORTANT NEW recommendation by stating that with you have stated that there will be a the quality now put into tubes, the fee and how much. -(CSEA) industry could actually dispense with SAMS BOOKS all warranties and make a policy of CALIFORNIA WAGES _. adjustment when and where necessary. INCREASED In this way, the industry could save RTA SCVSC directors at a recent hundreds of thousands of dollars in regular meeting made the following handling, and also do away with one changes in their pay scales: Electronic of its big by- products, namely the Apprentice pay begins at 50% of Organ Handbook "dishonest tube jockey who is often the journeyman's pay for the first 6 by H. Emerson Anderson plague of the service technician." months, increasing 5% each month, ONLY BOOK OF IT'i KIND with boosts of 10% each 6 months dur- ON THIS IMPORTANT SUBJECT ESFETA ON LICENSING ing the final year. Thus, the beginning han,ldmt < Here's all the information you At a recent meeting in Buffalo, N. Y., apprentice pay is raised from $1.32% need to get into this brand - new servicing market! Over Daniel Hurley, chairman of the Empire an hour to $1.50. The current journey- 1,000,000 electronic organs are Electronic Tech- man wage is $3 an hour. now in use. With your radio- State Federation of TV servicing experience, plus nicians Associations license committee, The increase is part of a program the wealth of sclunnatics, de- final the designed to make TV and radio serv- tailed operating Sate and presented a draft of ESFETA- troubleshooting information in 3 sponsored state license bill. A delegate icing more competitive with surround- this book, you'll be ready for ing industry which has lured many profitable service work in this big new field. Twelve from Long Island introduced a motion comprehensive chapters cover these popular organs: that the license bill include a provision technicians into manufacturing and Baldwin, Conn, Gulbransen, Hammond, Kinsman. shop owner as well research and development because of Lowrey, Thomas and Wurlitzer. First. chapter ex- for licensing the plains general operation of the electronic organ. Also as technicians. After debate, the motion fringe benefits. includes data on the Leslie organ speaker, the Conn was defeated. Then the bill was pre -. Strobotuner and Peterson Chromatic Tuner_ The book you've been waiting for! Over 140 illustra- $495 sented to the delegates for final ratifica- WINS "MAC" AWARD tions. 272 pages; 5% x 8% ". Only...... o! tion. The motion picture industry has the The vote to accept the final draft of "Oscar," television has the "Emmy" the bill was unanimous. and TSE (Television Service Engineers, Video Speed Servicing Inc.) has the "MAC." Just as the NEW VOLUME 5 G -E NEWS FROM ST. LOUIS Oscar and the Emmy are the highest Latest volume in Sam Marsh- Independent service dealers in St. awards in their respective fields, the all's very useful series. Consists of 456 more practical trouble- Louis were notified by General Electric MAC award is the highest honor which shooting hints for solving hard - that the company was discontinuing TSE can bestow upon a member or an to -find faults in major makes of 1959 -60 TV receivers. All "out of warranty" service. The news individual. models are indexed by brand marks the culmination of TEAM efforts This year the award went to Bob name, model and chassis num- VIDEO ber for quick reference. Each to get G -E to change its policy accord- Hester. It is inscribed, as always, "In hint is accompanied by an ex- ing to TEAM News. recognition of outstanding effort on planatory diagram or schemat- ic. An invaluable, time -saving Under the new policy, there will be behalf of the industry and the Tele- shop reference. 160 $fí195 franchised G -E service dealers with vision Service Engineers of Greater pages; 8% x 11". Only L approved telephone book listings, store Kansas City." identification, technical assistance, parts and service information. SERVICE CHARGES TV Tube Location Guide This story comes from the New York NEW VOLUME 10 THIS IS JUSTICE? State TSA News. Latest in this invaluable series. Gives tube location data for From CSEA member Lee Hoy comes We are finding it hard to raise our TV sets produced in 1959 -1960. this true tale. service charge to $5.95. If you find it Shows position and function of hard also, just tell people this incident tubes in hundreds of models In early March of this year, a man just find the trouble and re-- brought in a 14 -inch portable for an that happened in our shop. place defective tubes without A useless, idle loafer (bum) walked removing chassis! Shows major estimate. After checking it completely, into our shop asking for a handout. He component placement; signal Lee found two bad tubes and a shorted became furiously affronted upon receiving path; pin orientation on socket; picture tube and called the man, who a dime from a sympathetic bystander. series string filaments; fuse This "bum" said he had never been so location. Includes tube failure told him not to repair it, and that he check charts. 96 papes; 5%t x insulted in all his life. He vowed he would 8"; spiral bound. would pick it up in a few days. When never, as much as he needed it, take a Only 925 he came in, Lee asked for $3.50 for little old dime from any fellow being. the estimate fee and the gentleman ( ?) So, as you can see, even their prices p1S are going up. hit the ceiling and said that he would HOWARD RADIO CONT refer the matter to his attorney. FOR TV 8. AUTO ARTSNY STUDIES CITIZENS expanded- covers Subsequently, Lee received a letter BAND Vol. 3. Greatly from the attorney demanding the return ?radio models. tsrecommendedre the legal would taken. The Associated Radio Television controls of Centralob, of set or action be placementand Mallory. Sr this to his Servicemen of New York together with Clarostat, IRC Turning letter over own 812 x 11". Only...... attorney, Lee heard nothing more until RCA distributor Bruno -New York ran March 24, when he received an order to a technical demonstration and lecture appear in Small Claims Court on a on Citizens -band radio that, was open HOWARD W. SAMS & CO., INC. to the public. Held at the Central Plaza claim of $115.00, plus cost of the rental Order from your Sams Distributor today . of a television set while the set was Annex in New York City, it was con- or mail to Howard W. Sams 8 Co., Inc.,. De at. L -20 being held. ducted by Chet Gaven, Bruno's district 1720 E. 38th St., Indianapolis 6, Ind. sales manager. Each person who came Send me the following books: On April 24 Hoy appeared in court, "Electronic Organ Handbook" (EOA -1) before Judge Sims and was ordered to to the lecture received an application "Video Speed Servicing" Vol. 5 (VSM -51 release the set at no charge and pay for a Citizens -band station license. "Television Tube Location Guide" Vol. 10 (TGL.1 O) the man $30 for the rental of a TV "Replacement Control Guide" (RGC -31 while his was held. The reason- "Lee BBB TO SET STANDARDS, s enclosed. Send Free 3ook Lsr had not told the man that there would ARBITRATE DISPUTES Name be a charge, even though he did have Uniform standards of repair, ethical Address a sign posted, stating that a charge advertising and charges will be set by Zone _State would be made a proposed Television Service Dealers City for estimating repairs." (Outside U.S.A. priced slightly higher) The moral: Have a large sign posted Div. of the Better Business Bureau of NOVEMBER, 1960 113

www.americanradiohistory.com Memphis (Tennessee). "We have been handling about 1,000 public inquiries and complaints about for TV service each year," George V. Morse the BBB is money Jr., manager, said. "It quite apparent that the industry is suffering circuit by tubes by from a lack of public confidence and understanding. We all know that most SARGENT- of Memphis' 200 licensed shops are Amperex® honest and fair, but there is a fringe RAYMENT group who give the industry a bad name." The most frequent complaints were: replacing parts unnecessarily, charging new prices for used parts, low estimates and high prices, inadequately trained men and bait advertising. The BBB's new division will set up a code of ethics to which members would subscribe, undertake an adver- tising and public -relations program to regain public confidence (cost of pro- gram to be borne by qualified service dealers), set up a grievance committee to investigate complaints, set up an arbitration panel and a committee to work with city officials to get ordi- nances passed that will eliminate un- desirable operators. The BBB set up a similar group to handle complaints In designing the new SR -2051 100 -Watt Stereo Amplifier, and disputes in the the Sargent -Rayment engineers needed truly superior laundry and dry -cleaning industry. power supply regulation for the high rated output of this Their arbitration panel consists of two instrument. After intensive comparison tests, they chose laundry -cleaner industry men, two two Amperex 5AR4/GZ34 Rectifier tubes. housewives, a BBB official and two For Power Output, they wanted a tube with high effi- retailers. The panel does not know the ciency and high sensitivity, produced to standards of names of the principals in any dispute. absolute uniformity, in order to assure maximum power They are referred to as "Customer A" output, plus inaudible distortion. Their goal was achieved and "Dealer B." (ask Ampere>A, with four Amperex 6CA7 /EL34's Members These and many other Amperex `preferred' tube types of the program will be have proven their reliability and ,unique design advan- identified by decals in their shop tages in the world's finest audio components. windows. about hi -fi tubes Applications, engineering assistance and detailed data At the first organizational meeting, for hi -fi circuitry are always available to equipment manufacturers. Write: 26 firms signed applications to join Amperex Electronic Corp., Special Purpose Tube Divi- the program. sion, 230 Duffy Avenue, Hicksville, L. I., New York. NEW APPRENTICE PLAN OTHER AMPEREX TUBES FOR QUALITY HIGH -FIDELITY AUDIO APPLICATIONS A program has been planned to reduce POWER AMPLIFIERS RF AMPLIFIERS INDICATORS the number of steps between starting 6CA7 /EL34: w. 60 distributed load 6E58: Frame grid twin triode 6FG6 /EM84: Bar pattern 7189: 20 w., push -pull apprentice and journeyman technician 6ER5: Frame grid shielded triode IM3 /DM70: Subminiature 6805/EL84: 17 w., push -pull "excla- by the International Brotherhood of 6E117 /EF183: Frame grid pentode mation" pattern SCW5 /EL86: 25 w., high current, Electrical Workers Local 46, low voltage for IF, remote cut-off Seattle, SEMICONDUCTORS 6BM8 /ECL82: Triode -pentode, 8 w., 6E17/EF1B4: Frame grid pentode Wash. push -pull for IF, sharp cut -off 2N1517: RF transistor, 70 me According to Don Macpherson, the 6A08/ECC85: VOLTAGE 2N1516: RF transistor, 70 me AMPLIFIERS Dual triode for FM tuners business representative of the union, 6267/EF86: Pentode for pre-amps 2N1515: RF transistor, 70 me 6008 /EBF89: Duo -diode pentode the apprentice would work in the shop 12AT7 /ECC81:) Twin , low IN542: 2 12A117 /ECC82:} hum, noise and RECTIFIERS Matched pair discriminator days a week in his first year with the 12AX7 /ECC83: microphonics diodes other 3 days in school. The 6V4/EZ80: Indirectly heated, 90 mA second year 69LS /ECFeO: High gain, triode - IN87A: would have him in the shop 3 days a pentode, low hum, noise and 6CA4 /EZ81: Indirectly heated, 150 mA AM detector diode, microphonics 5AR4/G234: Indirectly heated, 250 mA subminiature week with 2 days spent in school. The What articles would you like to see published in RADIO -ELECTRONICS? third year would be spent in the shop Maybe you're the man to write them. Ask for an author's guide. full time. RADIO-ELECTRONICS 154 West 14th St. New York 11, N. Y. The apprentice would start at half the journeyman's pay as he does in the ENGINEERING DEGREE IN present program, but he would advance TAPE RECORDERS to full pay in two steps instead of the SCIENCE 127 or 36 MOS. HI -FI COMPONENTS previous three. MATH SLEEP LEARN KITS Mr. Macpherson said this would aid MERITAPE UNUSUAL _. Low cost. high VALUES the small shop that cannot afford to y ^ quality recording FREE 1961 CATALOG hire a full -time man or that cannot 3141.431- I lotttll tape. in boxes or cans. DRESSNER,69 -g2RE 114 St., Flushing 65, N.Y afford to have a full -time journeyman Accelerated year -round program prepares for early em- ployment in fields of Science and Engineering. Regular instructing the apprentice at all times. 4 -year program for 13.S. Degree compte ed in 3G months, special engineering degree program in 27. Classes start SERVICEMEN< quarterly- January. March. June, July, September. Quality TESA- SHEBOYGAN ELECTS education. Graduates employed from coast to coast. Gov- T. V. and TUBES ernment approved for veteran RADIO training. Students from 50 NAME BRANDS The Television and Electronic Service states. 40 countries. 20 buildings; dorms. gym. Campus. ALL TOP Save time and money. Earn board while studying. Write 60- 10-B% New -first quality -regular boxed -No Job - Association -Sheboygan County (Wis.) for catalog and complete information. lots, closeouts or pull -outs. SEND for catalog. elected 1711 E. Washington Boulevard, Fort (Representatives wanted for all states. Nigh Fred Leonard, president; Elroy Wayne 2, Indiana commission.) Van Shuy, vice president; Paul Miller, RADIO TUBE SPECIALISTS secretary ; John Bruder, treasurer ; and INDIANA TECHNICAL COLLEGE 397 -7th Ave., Brooklyn 15, N.Y. Roger Curtiss, NATESA director. END 114 RADIO -ELECTRONICS

www.americanradiohistory.com lc (ma) 330 300 300 Prar.i (mw) 150 150 ISO FIFE (1c =200 NENL ma, VcE =0.35) (minimum) (10) 10 15) 15 12C) 20

, TUBES 2N 1 564, 1565, 1566 and A gr.mp of general- purpose n -p -n

22K f I.E K

CODDUCTORS 8.2K INPUT

100 A µf ANEW semi- conductor device stands computer and switching applications. out this month. It is a de- The diagram shows a circuit for using 2N1564 vice called a Binistor. All other releases, these transistors as a non -saturating BASE COLLECTOR 2 N1565 2N 1566 with the exception of a TV damper switch cascade that operates at a 3 -mc EMITTER tube, are also in the semiconductor rate. 200° category. Maximum ratings of these Texas Instruments complementary pairs are: double -diffused silicon mesa transistors 2N1302-1303: 2N1304,-'1305: 2N- that cover an ac beta range front 20 to 2- N1302, 3 -1304, 5 -1306, 7 1 306 -' 1307 200. In free air, all three types have a VCB (25) 30 (25) 30 (25) 30 Three sets of complementary alloy - maximum dissipation of 600 mw. The VEB 25 25 25 junction germanium transistors for "Values in parentheses apply to n -p -n devices only. diagram shows the 2N1566 in a cas - -45V 45V

4.5K .5V EMI TTER OUTPUT 0 200" .5V -5.5V INPUT -.5V 0 -6V 2N1302,2N1303 -.5v 6.5V 2N1304,2N1305 I.9K 2N1306,2N1307 -45V TV -RADIO Servicemen or Beginners... The Firs` Practical Send for eort4- TV -RAD C- ELECTRON CS 7- Volume Job-Training Set Shop Library! on 7 -Day FREE ARIA[!

Answers ALL Servicing Problems QUICKLY . . . Like Having An Electronics xpert Right At Your Side! Makes You Worth On The VOL. 1- EVERYTHING ON TV- VOL. 5- EVERYTHING ON TV More Job! RADIO PRINCIPLES! 300 pages TROUBLESHOOTING! Covers all Put money -making, time -saving TV- RADIO- ELECTRONICS of practical explanations; hun types of sets. 437 pages; Illus- know -how at your fingertips- examine Coyne's all -new 7- Volume dreds of illustrations. trations, diagrams. VOL. EVERYTHING ON TV- TV- RADIO -ELECTRONICS Reference 7 2- VOL. 6-TV CYCLOPEDIA[ Itui..k Set for days at our RADIO-FM RECEIVERS; 403 and concise answers to TV ens:- expense! Shows you the way to easier TV -Radio repair -time pages; fully illustrated. saving, practical working knowledge lems in alphabetical order. ir- that helps you get the BIG VOL. 3- EVERYTHING ON TV- eluding UHF, Color TV and money! How to install, service and align ALL radio and TV sets, even RADIO CIRCUITS! 336 pages; Transistors; 868 pages. color -TV, UHF, FM and transistorized equipment. New photo- instruc- hundreds of illustrations, circuit tion shows you what makes diagrams. VOL. 7- TRANSISTOR CIIICUiT equipment "tick ". No complicated math VOL. 4- EVERYTHING ON SERV- HANDBOOK! Practical Re e,ence or theory-just practical facts you can put to use immediately right ICING INSTRUMENTS! How they covering Transistor Applications; in the shop, or for ready reference at home. Over 3000 pages; 1200 work, how to use them. 368 over 200 Circuit Diagrams,- 4.0 diagrams; 10,000 facts! pages; illustrated. pages. ALL 7 BOOKS HAVE BRIGHT, MODERN. SEND NO MONEY! Just mail coupon for 7- Volume TV -Radio Set on 7 -Day FREE TRIAL! We'll include the FREE BOOK below. If you keep the set, VINYL CLOTH WASHABLE COVERS pay only $4 in 7 days and $4 per month until $27.25 plus postage is paid. FREE BOOK -FREE TRIAL COUPON! Cash price only $24.95. Or return set at our expense in 7 days and owe nothing. Either way, the FREE BOOK is Educational Book Publishing Division yours to "LEARNED MORE FROM THEM keep. Offer limited. so act NOW! COYNE ELECTRICAL SCHOOL THAN FROM 5 YEARS WORK!" FREE DIAGRAM BOOK! 1455 W. Congress Parkway, Dept. BO -T1, Chicago 7, Illinois "Learned more from your first two h'e'll send you this big book, "17,0 Radio - volumes than from 5 years work." Television Picture Patterns and Diagrams Ex- r01 -NE'S 7- Volume Applied Practical TV- 4tAD10- plained" ABSOLUTELY FREE just for examin- I.I.I. I ItONII s Set for 7-Days FREE TRIAL per your offer. In elude ing Coyne's 7 -Volume Shop Library on 7 -Day Interns & Diagrams" book FREE! "Swell set for either the service- FREE TRIAL! Shows how to cut servicing time man or the beginner. Every service by reading picture-patterns, plus schematic stia- Name Aga bench should have one. "-Melvin grams for many TV and radio sets. Yours FREE whether you keep the 7- Volume Set or not! Mail Masbrueh, Iowa. coupon TODAY! Address City Zone State .._- _ ...... EL iPage 7, III D Check here If you want Set sent C.O.D. Coyne pays shipping SCHOOL charges. 7 -Day Money -Back Guarantee. J NOVEMBER, 1960 115

www.americanradiohistory.com caded audio amplifier. This circuit gives a typical current gain of 92 at 25 °C. spend one hour a day with either of these Characteristics of these Texas Instru- ments devices are: courses and prepare yourself BVc5o (breakdown voltage) (Ic =10 ma, IE =0) (max) 60 for a rewarding future Iced (reverse current) (Vice =40, IE =0) (max) (µa) I 2N1564 -1565 -1566 h,° (VcE =5, IE =5 ma,

f= 1 kc) 20 40 80 BASIC BASIC 3N56, 3N57 Called Binistors, these silicon n -p -n are designed for switching and ELECTRICITY ELECTRONICS storage circuits. Typical applications include ring counters, binary counters, shift registers and general- purpose switching circuits. two fabulous illustrated training courses now used by the U. S. Navy and the nation's leading industrial firms COLLECTOR

These are the same famous courses sponsored by the U. S. Navy to turn out INJECTOR trained technicians in record time! More than 100,000 trainees have already BASE learned the basics of electricity and electronics with this "learn -by- pictures" train- EMITTER ing course. What's more, the nation's leading firms rely on these courses to teach their personnel electricity and electronics. And, now you can learn these important 45° subjects in the same easy -to- understand way! 3N56,3N57 YELLOW DOT ON CAP' Here's why these courses are the easiest, fastest way to learn the basics of elec- 'INJECTOR IDENTIFIED BY tricity and electronics. Each idea is made completely understandable with specially created illustrations. These illustrations are so clear, so dramatic that you imme- Maximum ratings of these Transitron diately grasp the idea. There's at least one of these illustrations to a page, each units are: supported by text that is clear, concise and technically accurate. The illustrations and the text are the perfect combination to make the subject completely under- VcE 15 standable. (These courses are not available from the U. S. Govt. Printing OM.,, VcJ (collector to injector) 20 VcB 18 BASIC ELECTRICITY BASIC ELECTRONICS

by Van Valkenburgh, Nooger & Neville, Inc, by Van Valkenburgh, Nooger & Neville, Inc. IC (25°C) (ma) 30 Regardless of your previous education, you Only a knowledge of the basics of electricity IJ (injector current) (25 °C) can learn the basics of electricity with this is necessary for you to easily master the (ma) 30 "pictured- text" course. You will understand basics of electronics. More than 800 carefully Forward base current (lb on) the fundamentals of electricity and the role selected drawings make the function and it plays in our daily living. These funda- operation of vacuum tube diodes and power (25 °C) (ma) 30 mentals are applicable to the many electrical supplies, oscillators, amplifiers, receivers (I° off) you own devices and use - machinery and and transmitters crystal clear. This course (25 °C) (ma) 5 other equipment. More than 000 carefully will prepare you for a bright future in elec- selected illustrations supported by crystal tronics. What's more, it opens up many new, PtntI (mw) 150 clear text makes these subjects completely exciting hobbies -amateur radio, kit build- The 3N56 has a wider understandable: DC components and their ing, high fidelity. And even in business, it temperature circuits; AC components and their circuits; will speed your advance by helping you range than the 3N57 ( -65 °C to 150 °C AC and DC motors and machinery. understand situations that require a basic vs -55 °C to 100 °C). This character - A knowledge of electricity is the key to a re- knowledge of electronics. warding future in repair or maintenance iYtic makes the 3N56 suitable for mili- work. It's a step up the ladder to an even BASIC ELECTRONICS famous 5- volume tary applications. more rewarding field - electronics - where course available as heretofore, #170, Vols, I technical men are participating in the to V in soft covers, $10.00; )7170 -H, all Z 6CQ4 highest paid jobs in America. And, if you vols. in one cloth binding $11.50. just want to know about electricity for your An octal -based indirectly heated half - own information, you'll understand enough wave rectifier designed for TV damper to save many dollars in electrical repairs in BASIC ELECTRONICS Vol. 6 only -for the your home or be able to participate in ex- great many thousands who have completed diode service in horizontal deflection citing hobbies such as kit building, amateur the 5 volume course, can be purchased sepa- circuits. The design incorporates a radio, experimentation and hi -fi, X169, 5 vols. rately, #170 -6 soft cover $2.90; cloth, $3.60. soft covers, $10.00 per set; 4169 -H, 5 vols. glass- button suspension that is said in one cloth binding, $11.50. These and many other Ri der titles are available at bookstores, electronic parts distributors, d ept. stores or direct. Send for new catalog. Dept. RE -II But these books today -No matter TI .here you butt these books, we .Ouaran- tee satisfaction, or your money back urithin .f0 days of purchase.

JOHN F. RIDER PUBLISHER. INC. 116 West 14th Street. New York 11, N. Y. Canada: Chas. W. Poulton, Ltd., 66 Racine Rd., Reidale, Ont. India: Asia Publishidg House. Bombay ant other cities virtually to eliminate plate-cathode RADIO -ELECTRONICS pays $3.00 for good cartoon ideas and $15 and up for CARTOONS finished work mica arcing and permits a peak inverse RADIO- ELECTRONICS 154 West 14th St. New York 11, N. Y. plate voltage which is conservative for 110° autotransformer deflection sys- tems. Maximum ratings of the Westing- RENT LOOK house 6CQ4 when used in damper serv- no further . if you're stereo tapes searching for hi -fi sav- ice are: ings. Write us your re- OVER 1500 DIFFERENT ALBUMS 5,500 ó, quirements now. PIV POSTPAID TO AND FROM YOUR HOME 1,200 Key Electronics Company IP (peak) (ma) SEND FOR 1p 190 yy 120 -A Liberty St., N.Y. 6, N.Y. (ma) FREE BROCHURE stereo-parti eto IL Cloverdale 8 -4288 PP (watts) 6.5 811 -BA Centinela Avenue, Inglewood 3. California Heater- cathode voltages Heater neg with respect to: cathode 900 A NOTE TO THE HI -FI BUYER CATALOG O F AIR MAIL us your requirements for total dc and peak 5,500 an IMMEDIATE LOWEST PRICE QUOTATION HI -FI, RADIO, TV Heater pos with respect to: Components, Tapes and Recorders cathode 100 SHIPPED PROMPTLY PRICES PARTS & ACCESSORIES AT LOWEST - total dc and peak 300 WRITE TODAY FOR FREE CATALOG yacvut bolt tice aaáúcg 714 -R Lexington Ave. 2NI67I, -A, -B AUDIO ELECTRONICS MFG. CORP. UNLIMITED New York 22, N. Y. aire 355 BABYLON MPAE.- ROOSEVELT, N. T. A series of silicon Unijunction tran- 116 RADIO -ELECTRONICS

www.americanradiohistory.com TRANSISTORS at fabulous discounts

RF MIXERF and F lEt ec,

9AF:39UTPUT 3 9 y'

AUTO TYPE U?: POWER OUTPUT AL HIGH POWER a INSIST ON RAD -TEL FOR EVERY TELEVISION AND RADIO TUBE NEED 15 AMP Collector Currert Up to 75% OFF on BRAND NEW TUBES

GUARANTEED ONE FULL YEAR! You Can Rely On Rad-Tel's Speedy One Day Service! Not Used - Not Pulled Out Of Old Sets Each T be Individually and Attrac tively Boxec! 1 Qty. TYR Price Sty. Type Pr ce Qty. Ty.e Sty. Type Price Price Qty. Type Price Sty. Type Price Qty. Type Price Qty. Type Price Qty. Type 'rice -0Z4N .79 3DT6 .50 _64B+8 .46 .62 _6816 -6EU8 .79 _12A4 .60 _12896 .50 _12EG6 .54 _19BGi 1.39 _1AX2 .62 .80 -6ÁC7 .96 .-305 -6BK7 .85 _6EA8 .79 -12A85 .55 _128E6 .53 -12EZ6 .53 _1918 .80 _1133.17 .79 .61 -6ÁF3 .73 _3S4 _6BL7 1.00 -6H6GT .58 -12ÁC6 .49 _128F6 .44 _12F5 .66 -21E86 '.49 _1 DNS .55 -3V4 .58 -6ÁF1 .97 _6BN4 .57 _12A06 .57 -615GT .51 _12BH7 .73 -12F8 .66 -25808 1.11 _1G3 .73 _4BC5 .56 SA63 .65 .74 -12ÁE6 .43 -6BN6 -616 .67 _12816 .56 _12FM6 .45 -25C5 .53 _113 .73 _46C8 .36 -6ÁI.6 .99 .65 _12ÁF3 -6805 -6K6 .63 .73 -12806 1.06 _12K5 .65 -25CAS .59 _1K3 .73 -46N6 .75 -6AIG .95 _6806GT 1.05 -12ÁF6 .49 -6S4 .48 12BY7 .74 12SA7M .86 -2506 1.44 _116 1.05 -4807 .96 _641.3 .47 .95 _6807 6SA7GT .76 -12416 .46 12617 .75 - 12SK7GT .74 -25C1.16 1.11 _1LN5 .59 4658 .93 _6ANY3 .78 - - -69R8 .78 -6BK7 .74 12ÁL5 .45 _12C5 .56 -12SN7 .67 -25DNs 1.42 _1R5 .62 -40118 .71 _6AN4 .95 -6008 .70 _12A18 .95 -6517 .80 -12CÁ5 .59 -12SQ7M .73 _ _25EH5 .55 _1S5 .51 _48Z6 .58 6ÁN8 .85 _6BY6 .54 _12A05 .52 - -6SN7 .65 _12CN5 .56 _12U7 .62 _2516 .57 -1T4 .58 -48Z7 .96 -6A05 .50 -6BZ6 .54 _12476 .43 -6507 .73 _12CR6 .54 _12V6GT .53 _25W4 .68 _1 U4 .57 _4CS6 .61 .55 -6BZ7 .97 _12AT7 .76 -6Aß5 6T4 .99 _12CU5 .58 _12W6 .69 _25Z6 .66 _1U5 .50 _40E6 .62 -6AS5 .60 _6C4 .43 -12ÁU6 .50 408 .78 -12CÚ6 1.06 _12X4 .38 _35C5 .51 _1X26 .82 40K6 .60 _6AT3 .43 6CB6 .54 -11AÚ7 .60 - _6V6GT .54 _12C86 .54 _17AX4 .67 -3516 .57 40T6 .55 .79 .67 _12AV5 .97 tAF4 .96 -6A13 _6C06 1.42 _6W4 _120B5 .69 _171306 1.09 -35W4 .52 _5AM8 .79 6A1í3 .82 -3AL5 .42 -6CF6 .64 -6W6 .99 _12ÁV6 .41 _120E8 .75 _17C5 .5B _35Z5ET .60 -5ÁN8 .86 .-6A16 .50 .60 .39 _12ÁV7 .75 -3AU3 .51 -6CG7 _6X4 _12918 .85 _17CA5 .62 -50B5 .60 _5ÁQ5 .52 -6AÚ1 .61 _12AX4 .67 _6CG8 .77 _6X5GT .53 _12DM7 .67 _1704 .69 -5005 .53 _3AV6 .41 -5ÁT8 .80 _6ÁíE .87 -6CM7 .66 _6X8 .77 -12AX7 .63 _12D06 1.04 _17906 1.06 _500C-- .37 -3BA6 .51 -5BK7A .82 6AV3 .40 - -6CN7 .65 _7ÁU7 .61 _12AZ7 .86 -12057 .79 _1716 .58 _50EH: .55 -38Ci .54 _51307 .97 __6ÁK8 .89 _6CR6 .51 _748 .68 1204 .63 _120Z6 .56 _17W6 .10 5016 .61 _3BE6 .52 58R8 .79 6AX3 .65 _ - - _6CS6 .57 -7B6 .69 _128A6 .50 _12EL6 .50 19AÚ4 .83 _11722 .61 _3BN6 .76 .76 _5CG8 6AX7 .64 -6CÚ5 .58 -7Y4 .69 3BUI .78 _5C18 .76 -6BAô .49 _6CU6 1.08 BAU8 .83 _38Y6 .55 _5E48 .10 -6BI .54 4CY5 .70 _SAWS .93 Not a Kit, but Completely Wiled _3BZE .55 _5EU8 .80 _6BC7 .94 -6CY7 .71 _8605 .60 -3CB6 .54 .68 _516 -6888 .97 _6DÁ4 .68 B- CG7 .62 _3CFE .60 578 .81 -6806 .68 _ 6985 .69 _8CM7 .68 - . .52 --) .-3CS6 _5U4 .60 -6BE3 .55 -6DE6 .58 _8CN7 .97 STEREO AMPLIFIER. -3CY5 .71 5U8 .8' 613E3 .44 __6006 .59 _8CX8 .93 .60 -3DK6 .__5V6 .56 __6BM 1.66 _6006 1.10 _8E88 .94 4X8 .78 -6BN6 .65 __6DT5 .66 _100A7 .71 CHASSIS _5Y3 .46 -6BIE .87 _ -.69T6 .53 _11CY7 .75 $A.9511Lots of 3 LI Single, $5.95 ea. SEND FOR FREE TROUBLE SHOOTER GUIDE AND Set of tubes: 2-35C5; NEW TUBE & PARTS CATALOG. 1- 12AX7; 1 -35W4 $1.15 Set of 3 g ey 1" kn ;1: 30c AFFILIATED WITH ANY OTHER MAIL ORDER TUBE COMPANY.

55Chamkers St RAD-TEL TUBE Newark `_, N.1. TERMS: C 25% deposit must accompany an orders - balance C. O. D. $1 HANDLING CHARGE FOR ORDERS UNDER $5. Subject to prior sale. RE-1168 Please add postage. No C. O. D.'s outside continental U. S. A.

NOVEMBER, 1960 117

www.americanradiohistory.com sistors useful in oscillators, timing cir- ....._ . .' . ,. .. ".: ,;, e cuits and pulse generators where they can serve the purpose of two conven- t t tional silicon or germanium transistors. 'feud t t .-C'6/4VER tea i.uttheorsegt The 2N1671 is intended for general - purpose industrial applications. The LAG -55 AUDIO GENERATOR 2N1671 -A is intended for industrial use SINE SQUARE in firing circuits for silicon controlled rectifiers (see diagram) and other ap- A multi- purpose generator for measurements on audio equipment vr" 2N167I-A +V1 -amplifiers, speakers, networks, ayDlO AC RB2 tón DC Three waveforms : sine, square and 0011 complex for all types of measure- .200" ments including response, distor- SILICON CONTROLLED tion, transient and I -M distortion REGT

checks. Full range is from 20 BASE I to 200,000 cps, output 5 volts BI EMITTER with minimum amplitude variation BASE 2 throughout whole range. 2N1671 -AoRB plications where a guaranteed minimum pulse amplitude is required. The 2N- 1671-B is intended for applications in the more than countries, The LEADER test instruments ore being used 36 where a low emitter leakage current attesting their excellence in design, performance and usefulness. and a low peak point emitter current (trigger current) are required. OHMATSU ELECTRIC CO. LTD. Maximum ratings of the General 850 TSUASHIMA -CHO KOHOKU -KU YOKOHAMA, JAPAN Electric 2N1671 series are: Ptetal (mw) 450 IE (ma) 50 HI -FI .; STEREO IE (peak) (amps) 2 SERVICEMEN COMPONENTS Vg (reverse) 30 FREE TO OUR TUBE CUSTOMERS Send us your list for a PACKAGE DEAL QUOTE HT -I through HT -10 A MINK STOLE SPECIAL No sale too small. Tradeins accepted. BONAFIDE of- A series of silicon tunnel diodes de- FOR YOUR BEST GIRL fers biggest discounts on all standard brands. Expert advice and lull guarantee are assured at Top name brands -First quality -Brand New -Full signed for use in digital pulse circuits, replacements. -800/ off-plus FREE tube bonus. WRITE FOR DETAILS BONAFIDE ELECTRONICS gating, memory matrices, negative re- /_ St., N.Y. 7, N.Y. TUBE SPECIALISTS Dept. RE -11, 89t Cortland RADIO WE WILL NOT BE UNDERSOLD sistance amplifiers and microwave oscil- 397 -7th Ave., Brooklyn 15, N.Y. lators. NOTE ANODE CATHODE ANODE PINS CONNECTED all new edition INTERNALLY ANOD CATHODE up -to -date HT- I CONNECTED THROUGH TO CASE component prices HT -10 All will handle a maximum of 200 -ma PLUS forward current and 200 -ma reverse the quick easy way current. Electrical characteristics of these to figure service charges Hoffman tunnel diodes are: Peak Voltage Voltage Typical Neg Type Current at In at Iv Resistance (ma) (mv) (mv) (ohms)

HT- I I .0 65 420 220 HT -2 1.2 65 420 180 HT -3 1.5 65 420 I50 OFFICIAL PRICING DIGEST HT -4 1.8 65 420 120 VOL. 4, NO.1 BEST 65 420 100 Wet Ze.soS TRAIN QUICKLY! OLDEST, HT -5 2.2 Flat rate and hourly EQUIPPED SCHOOL of ITS KIND in U.S. HT -6 2.7 65 420 83 68 service charges, Get practical training in New Shop -Lairs of Coyne. HT -7 3.3 65 420 Prepare for a better job and a successful future in a HT -8 3.9 65 420 56 based on and show- top opportunity field. Advanced education or pre- ing regional and vious experience not needed. Employment service to HT -9 4.7 65 420 47 graduates. 420 39 national averages, Later HT -10 5.6 65 Enroll NOW -Pay Note: I is current at peak of characteristic plus up -to -date list Finance Plan and IStly Payment flan. Also Part is at lowest help for students. curve. Iv valley current (current or resale prices on Time Employment point on negative -resistance slope). END over 63,000 cornpo- Clip coupon or write to address FREE BOOK below for Free Illustrated Book. nents, Arranged al- ''Guide to Careers"- Describes all training offered. phabetically by man- No obligation and No Snlc:arnan Will Call. Act NOW. CORRECTION B.W. Cooke. Jr.. President CHARTERED There is an error in the value of ufacturers and prod- NOT PROFIT by Established 1899 the bank used to develop the ucts, numerically 1501 W. Congress Pkwy. capacitor - Dept. BD . 61,000 st.r,"..,a part number. Corn Chicago, 5,000,000 -ampere arc described on page size pact, convenient ruse this coupon to get our free book 45 of the September issue. The value fits in tube caddy, (390,000) is in µf, not µµf. This is or pocket. "GUIDE TO CAREERS" toolbox ttaininr. apparent from the words immediately $2.50 per copy from COYNE ELECTRICAL SCHOOL at Coyne Pkwy. wrong value, which state 1501 W. Congress training following the ...... your distributor. ....-... ,'. A+..d Chicago 7, III. Dept. of Electronics 6D E at home that the bank is made up of 2,000 of almost 200 Af each. NAME capacitors ELECTRONIC PUBLISHING COMPANY, INC. Our thanks to Mr. H. Q. Duguid, of ADDRESS this to our 180 N. WACKER DRIVE, CHICAGO 6, ILL. CITY STATE Darien, Conn., for bringing Unlike most other schools, we do not employ salesmen.) I- attention. RADIO -ELECTRONICS 118

www.americanradiohistory.com NOTEWORTHY

SIMPLE STEREO AMPLIFIER This circuit was described in the cartridge connected to its input, the March, 1959, issue of the French maga- amplifier is quite versatile. It has a zine Le Haut -Parleur. It is a simple rather elaborate group of controls: a stereo amplifier used in portable stereo MODE control for selecting the type of ECC82 /I2AU7 EL84/6BQ5 loc µf VOLT AMPL DRIVER PWR AMPL

VIG V2 7 2.7K I00K 21MEG .05 1.5K 2 OUTPUT z=2.5n CHAN I H TRANS INPUT (XXTAL) 470K . . 3 .001 ¡47 K 411 I I.SK 1.5 o- VOLUME ,,/ K 50 4 150.11 2=5K o o--. ISO CHAN 2 d], INPUT 100K 3K /5W (XTAL) WW TOP )I -I IMEG --MV4-- IOOK OUTPUT TRANS 100µµf .05 CHAN 2 150K so T $MC 50" MODE/ I_ 350V I- REVERSE STEREO 270µµf .001 2 -CHAN I MONO 250 V TREBLE only for those who want the L'l'.. - ate 3- STEREO I00K BASS TO PWR 4 -CHAN 2 MONO TO V1LT 500K 500K AMPL G2 AMPL GRID CHAN 2 CHAN 2 .0022 .0022 100 K HTR PINS -VI=4,9,5 V2=4,5 I SERUUD-S-3UUU I

FM /MX STEREO TUNER record players. Only one channel is operation, a dual VOLUME control and shown. The actual unit uses two separate SASS and TREBLE controls. The FM tuner that has everything .. _0.95µv ECC82's, two EL84's and a common Feedback over two stages is used - sensitivity, Interchannel Hush noise meting power supply. Despite its being un- from the secondary of the output trans- system, "Acro -Beam" tuning eye, cascade bal- complicated and requiring a crystal former to the driver tube's cathode. anced input, automatic frequency control, "local- distant" switch ... now brings you TRANSISTOR PU LSE INTEGRATOR the only Integrating the pulses from a high - tube. This minimizes current drain FM TUNER with "CORRECTIVE" low- is from the high- voltage battery. impedance current source dif- INVERSE FEEDBACK ficult. In this specific problem, I wanted In the pulse integrator part of the to integrate the pulses from a stand - circuit, the high- voltage low- current Every high fidelity amplifier today incorpor- and Geiger tube to provide a meter in- pulses are stepped down through a ates "corrective" inverse feedback for lower dication with a minimum of circuitry. transformer to low-voltage high -current distortion and improved response. Now, Sher- a The same circuit and method will prove pulses. Almost any interstage trans- wood brings the same performance benefits useful in many similar applications. former can be used here. I used a Chi- to the S -3000 III FM Tuner; these include The diagram includes a high -voltage cago 13M -112 to keep size down. Con- reduction of distortion due to overmodulation power supply. Complete information on nect transformer secondary leads for by the FM station and better quality long - this part of the circuit may be found maximum current. One way provides distance reception. in RADIO -ELECTRONICS, February 1957, four times as much as the other. page 58. Resistor R should have the The pulses are rectified and in- READY FOR FM STEREO largest value that will let 10 µa be tegrated by germanium diode D and drawn through the voltage -regulator capacitor C. The average dc is then Stereo via FM multiplex broadcasting is just around the corner. The S -3000 III contains MERIT FIL TRANS chassis space and all control facilities to plug 2N255 P -2945 IKV /1.5MA CK1038 CK705 CK721 o-o osc OR EQU V SEL RECT VOLT PULSE INTEG in a stereo multiplex adapter. Other features SEC PRI REG AF TRANS D f-470 1.5V BATT PULSE AMPL sr/ include flywheel tuning, plus 7" expanded 101 slide rule tuning scale, cathode -follower out- i .5 put, and front panel output level control. ADJ IOOV Z 200K Sherwood Electronic Laboratories, Inc, 4300 500µf MIL N. California Ave., Chicago 18, III.

BASE 2N255 CK1038 ( *) Other fine Sherwood Tuners: S-2000 AM -FM Tuner $145.50 1.5V BATT IB85,CK1026 OR EQUIV II RED S -2200 AM -FM MX Stereo Tuner $179.50 DOT COLLECTOR EMITTER IK IA IK For Complete Technical Details Write Dept RE -II NOVEMBER, 1960 119

www.americanradiohistory.com amplified by a 1 -stage transistor ampli- Geiger tubes may be paralleled. A dc fier. No serious attempt to use a 2- amplifier with higher gain also in- stage amplifier was made as all the creases sensitivity. If you are a career -minded simple two -stage circuits have too much The entire unit can be packaged in a engineer or technician . drift. very small box if miniature components With this circuit, the 50 -µa meter are used, but even with full -size less - gives a full -scale indication when the expensive parts the unit will still stay RE- DIRECT your Geiger tube is held in a 5.0 -mr /hour in the miniature class. Edwin N. radiation field. To increase sensitivity, Kant man future aims to REMOTE -CONTRO L TRANSMITTER This four -transistor Citizens -band with feedback through the crystal taken high standing (27.255 -mc) remote -control transmitter from a tap on the collector coil. Cl circuit appeared in a Texas Instruments tunes the circuit to the crystal fre- in NUCLEAR application note. A crystal oscillator quency. A common -emitter power ampli- 2N 1107 2N 1107 ENGINEERING osC PWR AMPL technology

Learn Nuclear Engineering Tech- nology through an advanced home study program offered by CREI Atomics. Enrollment is limited.

ONLY A LIMITED NUMBER OF MEN LI -16T N°22 ON 5/8" DIA AIR CORE,'" LNG,TAPPED 3-1/2 T FROM GND END will be accepted at this time for this L2-15T a " " " " " " ,15/16" LNG,TAPPED I-1/2T FROM GND END program of home study offered by (BOTH AIRDUX 516 OR EQUIV ) CREI ATOMICS, an expertly- staffed and a keyed power amplifier make up fier is used, and it is triggered on and extension division of The Capitol the rf portion of the circuit. The mod- off by the two -transistor multivibrator. Radio Engineering Institute. ulator is a free -running of multivibrator Naturally, output power is well under U.S. Atomic Energy Commission which keys the power amplifier at an the 30 -watt limit, so before using the states about the severe shortage of audio -frequency rate. unit make careful tests to determine its trained people in nuclear technology: The oscillator is a common -base stage effective range. . the immediate goal is to retrain, through short courses ... those al- AVC FOR HALLICRAFTERS S -94 ready grounded in traditional disci- The Hallicrafters S -94 is an eight - 68H6 plines." Through CREI Atomics you tube ac -dc set that covers 30-50 mc. CADD RF AMPL now v212AL5 can combine your present tech- This band includes civil defense, fire, RATIO nical education and engineering ex- police and other important communica- ä; perience with knowledge in nuclear DE)T__,.._ tions. The receiver has built-in relay BRAK 1 5 ' engineering and technology. The re- J squelch which grounds the control grid I sult: increased career opportunities 470K I of the audio output tube when there is L- JVvsr -t ---"\nn"- -1 and corresponding income advantages no incoming IMEO signal. However, annoying T01/400V as the nuclear field develops. blasting may occur, for example, while .L Program of study includes - tuned to a police department whose Nuclear Physics, Reactor Physics, Thermodynamics, patrol cars and central station transmit Reactor Technology, Reactor Controls, Instrumentation for Reactor Control, Isotopes, Health Physics-many on the same frequency and a patrol car Connect a 250 -µµf ceramic capacitor other subjects is transmitting while close to your re- between this wiring and pin 1. Also ceiver. This blasting is not only annoy- connect a 1- megohm and a 500,000 -ohm ing, but speech may become unintel- resistor in series -the 1- megohm unit to ligible. pin 1 of the 6BH6 and the 500,000 -ohm The modification shown here will give unit to pin 2 of the 12AL5 ratio detec- automatic gain control to minimize such tor. From the junction of the resistors blasting. Simply disconnect all wiring connect a .01 -µf 400 -volt capacitor to from pin 1 of the 6BH6 rf amplifier. ground. Carl C. Seidler END 50 pears ego In Gernsback Publications USE THIS COUPON TO REQUEST DETAILED CATALOG r Does Wireless Affect Homer Pigeons? HUGO GERNSBACK, Founder CREI Why Do Wireless Waves Travel Far- Atomics 1411 -G Modern Electrics 1908 3224 16th Street, N.W. Wireless Association of America 1908 ther By Night Than By Day, by Electrical Experimenter 1913 Washington 10, D.C. Radio News 1919 Professor W. Weiler (University Science & Invention 1920 Please send me complete information Television 1927 of Esslingen, Ger.) Radio -Craft 1929 about CREI ATOMICS. Short -Wave Craft 1930 A Simple Current Gauge, by Austin Television News 1931 name C. Lescarboura. of an Exhausted Coher- Some larger libraries still have copies of Modern Electrics Construction street on file for interested readers. er, by Kreigh B. Ayers, E.E. Unique Signaling Device. city state In November, 1910, Modern Electrics New Liquid Microphone. job title Prevention of Interference by Selec- Design for an Oscillation Auto- Trans-

I- tive Apparatus, by G. F. Worts. former, by M. A. Deviny. 120 RADIO -ELECTRONICS

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Pf PLE IA twist -mount capacitors in new clear Sencore, Addison, Ill., is building dom Die, They Just Fade Away," fea- plastic tubular Vu -Paks which are re- a new addition to its present plant tures the Mighty Mite tube checker. usable for storing small parts anc. tools. which will nearly double capacity. Herb Sylvania Electronic Tubes Div.'s re- George C. Connor (left) was elected Bowden, Sencore president, is sur- a senior vice president of Sylvania Elec- rounded by plant personnel and well tric Products, New York, with responsi- wishers as he breaks ground for the bility for the company's marketing ac- tivities. He had been regional sales vice president -East. William O. Spirdc was

ceiving tube operations won the presi- appointed vice president -sales of Syl- dent's Safety Citation for 15 months of vania Electronic Tubes Div., New York. operating without a single disabling in- He had been equipment sales manager jury. Matthew D. Burns (left), presi- for the division. He succeeds Donald W. new addition. Sencore recently released dent of the division, presents the award Gunn, who is now regional vice presi- the third in its series of slide films on to Walter A. Weiss (right), vice presi- dent of Sylvania, covering marketing how to use Sencore testers in servicing. dent in charge of receiving tube opera- activities in the 12 Western states and The latest in the series, "Old Tubes Sel- tions. Hawaii.

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PEAKING COILS popular types $1 iess 51 5 SETS SPEAKER PLUGS ", "I Si 10 - ASST. VOLUME CONTROLS 10 - TV CARTWHEEL CONDENSERS 10kv 51 - with =, $1 SETS PLUGS and PIN JACKS $1 5 - ASST. VOLUME CONTROLS 3 TV CARTWHEEL CONDENSERS 201tv $1 10 - PHONO - 20 ASST. PILOT LIGHTS i..naa ur- . 51 2 NEEDLES 401) playing' $1 - 2 TV CONDENSERS 30kV 51 - $2.50 SAPPHIRE ,0,.t ,I 51 E - CARTWHEEL , trio . $1 10 - PILOT LIGHT SKTS. , 1 .I.sme 51 4 ELECTROLYTIC CONDS. s0.400v - TV RATIO DETECTOR COIL - 50 - ASST. TERMINAL STRIPS I. 2 51 1 & mmf Si - TV RATIO DETECTOR COIL 10.7,me $1 35 - MICA COND. 20-50 mmf 15-68 10 - ASST. RADIO ELECTRO. CONDENSERS 51 1 - TV SOUND I.F. COIL I.s n, . $1 35 - MICA COND. 20-100 mmf & 15-270 mmf $1 5 - ASST. TV ELECTROLYTIC CONDENSERS 51 _ 1 - TV VERT. BLOCKING TRANS. standard, 51 35 - MICA COND. 20-470 mmf & 15-680 mmf $1 25 - ASST. MICA TRIMMER CONDENSERS 51 1 TV 270. :t to or 170 ohms - FOCUS COIL 51 35 - MICA COND. 20-820 mmf & 15 -1000 mmf S1 15- TUBULAR CONDENSERS I -u00, Si 1).1 3 HV RECTIFIER SOCKETS i nrnted $1 - 35 -MICA COND. 20- 2200mm1 &15- 2400 mmf , $1 15 - TUBULAR CONDENSERS .047 -noon 51 3 HV RECTIFIER SOCKETS I ,n mte, $1 - 35 - MICA COND. 20 -6800 mmf & 15 -10000 mmf 51 10- TUBULAR CONDS. .17-boot .... Si E 1 TV SYNCHROGUIDE COIL #205R1 $1 - 35 CERAMIC COND. 20-5 mmf & 15-10 mmf 51 10 - ELECTROLYTIC CONDS. I00/25.5 -,s. ...S1 515 - "JACKPOT" TELEVISION PARTS Si - 35 - CERAMIC COND. 20-15 mmf & 15-47 mmf S1 2 - ELECTROLYTIC COND. 10.450v...... $1 3 - TV ALIGNMENT TOOLS assortment n I 51 35 CERAMIC COND. 20-56 mmf & 15-82 mmf $1 3 - ELECTROLYTIC COND.5., 10.150v...... 51 E 3 - TV ALIGNMENT TOOLS .,ssortmomt .2 51 - 20-100 mmf & 15-IS0 mmf 51 3 ELECTROLYTIC COND. so- I5uv .. Si 3 - TV ALIGNMENT TOOLS n..ortment 35 - CERAMIC COND. - ...... & mmf $1 35 DISC. 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with the CBS Electronics, Danvers, Mass., is RADIO offering distribu- SEG DEMONSTRATION SYSTEM tors a colorful new Radios sell immediately Tools and Service MIT NNE_ on demonstration ROOF aids floor - easel Completely hidden merchandiser. W. Walter Watts (left), recently No direct connection elected chairman of the board and pres- Simple to install ident of RCA Sales Corp., in addition to FM & Shortwave outlet his post as RCA group vice president, was elected a director of Radio Corp. of The new Master Radio Demonstration system America. He succeeds Dr. Charles B. is a "must" for every retailer who sells AM, FM or short- Jolliffe, vice president and technical di- wave radios. Powerful signals are sent out by concealed Demonstrate with Pride -No Excuses rector of RCA. Dr. Jolliffe retired last loop antennae to give all the radios on your display shelves strong and clear input signals ... permitting them to function at the peak of their capacity, despite interference from fluorescents, elevator starting motors, or any other steel construction in the building that might introduce noise or weaken the signal. SUPER POWERED SINGLE CHANNEL AMPLIFIER 20V OVER -5 WATTS OUTPUT year but continues to serve the corpora- DELIVERS TREMENDOUS SIGNALS OVER LONG DISTANCES tion on special assignments. RCA also Channels 2 -13 Response flat ± 2db Linear Class -A operation announced the consolidation of institu- Over 26db gain Input 1 Volt max. C. C. S. Service tional and staff advertising and sales 6-8 mcs band width 75 OHM Termination promotion activities under R. H. Coffin U. S. Govt. Install. Panama Canal Zone, Iwo Jima. Write for details today (right) as staff vice president, adver- tising and sales Promotion. He had been director, advertising and sales promo- SEG ELECTRONICS tion, and a vice president. 1778 FLATBUSH AVE. BROOKLYN 10. NEW YORK Raymond T. Leary has been named vice presi- on everything in dent- marketing of a: - Cornell Dubilier Electronics Div., stereo hi-fi Federal Pacific Co., South and Electric Plainfield, N. J. He

electronics had been gins I al sales manager. Robert E. Svobo- Dramatic Events Recorded First send for the 1961 da, manager of the Time From Short Wave Radio! Amphenol Distribu- President's voice from outer space tor Div. of Amphe- ALL /ED ... police capture of a gunman ... nol - Borg, Broad- CATALOG radio contact with record altitude view, Ill., was flight! Many other fascinating, his- made president of events planes, foreign toric -ships, the division. stations -all transcribed on a lim- ited- edition recording, "The Amaz- James W. Noland Listening," 444 -PAGES VALUE PACKED. Write today ing World of Short Wave is now general for the leading Electronics Catalog. World's narrated by world -famous news- manager of the largest selection, including products and caster Alex Dreier. If you're alert, values available only from ALLIED.SAVE ON: Gonset Div., Young adventuresome, send for this re- Spring & Wire Everything in Hi -Fi Music Systems d Com- markable recording today! ponents Biggest Selection of Hi -Fi Cabinetry Corp., Burbank, Exclusive Knight® Super -value Stereo As heard on Hallicrafters precision Calif. He was for- Knight -Kits`? -Best in Build- Your -Own Hi- receivers, $59.95 to $395.00. Fi Tape Recorders and Phono Equipment merly manager of Everything in Electronic Parts, Tubes, Tran- sistors, Test Equipment, Amateur Gear, P.A. manufacturing. Systems, TV Accessories, Tools, Books. Harold E. Luber, director of student Save most at ALLIED. Write services at National Radio Institute, FREE 1961 today! only $2 down for Catalog Washington, D. C., was appointed ex- on orders ® -7,7 6ot® ®°®- up to $50 ALLIED RAD I 0 ecutive vice president. Everett A. Corey, r formerly with Capitol Radio Engineer- ' Department 23 , ' ing Institute, joined NRI as special rALLIED RADIO, Dept. 103 -L allicrafters Chicago 11, III. 100 N. Western Ave., Chicago 80, III. Vh assistant to president J. Morrison Smith. IEnclosed is 250. Please rush'The Amaz- Edward L. Degener, general manager, Send FREE 1961 ALLIED Catalog. ing World of Short Wave Listening.' and an NRI employee for 42 years, re- Name NAME tired. ADDRESS Sam Poacher of Newark Electronics, Address LCITY STATE Chicago, was elected president of the Electronic Industry Show Corp. for 1 1 City Zone State I L J year. Other new officers are: Robert D. 122 RADIO -ELECTRONICS

www.americanradiohistory.com Ferree, International Resistance Co., vice president; Norman Triplett, Trip- lett Electrical Instrument Co., secretary, and Robert E. Svoboda, Amphenol -Borg TV TUNERS OVERHAULED MAKES VHF Electronics, treasurer. AND $9.95 OR Obituaries ALL MODELS NET UHF Bond P. Geddes, radio industry pio- UHF /VHF COMBINATION- S19.90 neer and for many years executive vice 90 DAYS WARRANTY president and secretary of the Radio Manufacturers Association (now the EIA), in Washington, D. C., at the age SAME DAY SERVICE of 78. ON POPULAR TYPES-48 HOURS MOST OTHERS William A. Nicely, vice president and general manager of CTS Corp. (former- Overhaul charge includes labor and minor parts; tubes and ly Chicago Telephone Supply Corp.), in major parts are extra at net prices. Elkhart, I ml., after a sudden illness. Tuner to be overhauled should be shipped complete; in, lude i William H. Miller, sales manager Jer- tubes, shield cover and any damaged parts. Quote model rold Electronics Corp., Philadelphia, of and state complaint. Pack well and insure. a heart attack at the age of 48. WE WILL SHIP C.O.D.- F.O.B. CHICAGO OR TORCN -0 David H. Ormont, president of Hud- son Radio & Television Corp., New York, in an automobile accident in Las Vegas. eastie Tv 11441.94 swtoice, 9fric. Wesley M. Angle, president of Strom - berg- Carlson Co. from 1934 to 1945, 5710 N. WESTERN 136 MAIN ST. CHICAGO 45, ILL. U.S.A. TORONTO 13 CANADA suddenly at his summer home in Kenne- bunk, Me., at the age of 77. END Suppliers of rebuilt TV Tuners to manufacturers, technicians d service dealers, coast to coa:.

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TECHNICIANS" l;:U.E \IIAR We hear, with increasing frequency, STAMP OF APPROVAL that the inequities of our calendar are A mail -order tube advertisement in RADIO- ELECTRONICS is it own stamp of approval -your assurance that you will get who, yoe pay the source of much business woe. Many for when you order. Since January, 1956, RADIO -ELECTRONICS has plans have been submitted and a special insisted that mail -order tube advertisers tell you that their tubes are new and unused, or if they're not -that they are seconds, rejects or UN committee of international experts otherwise imperfect. Over the years this has cost us thousands of is discussing a 13 -month calendar. dollars in advertising -but it has protected you. Not to be outdone, and as another special service, the following calendar is being submitted for the benefit of hard- pressed service business: Purchasing NMI. Nat. Fat. Frl. non.. w,"1. Tur. your assurance OISE" 8 7 6 5 4 3 2 "No of brand name A HI -FI 17 16 14 13 12 11 9 24 23 22 21 20 19 18 quality PRODUCTS SYSTEM? 31 30 29 28 27 26 25 PARTIAL LIST NO -NOISE Here are the 'reasons why you will OF BRANDS like it: TUNER -TONIC Send Us IN STOCK with PERMA -FILM Jim Lansing 1. Each month starts with a Sun- Your Altec Lan' iag day, a day of rest. After all, who can Cleans. lubricates. Electrovoice 'Ngocsr sf restores all tuners. Jensen rest properly if he's too tired from reu.. including wafer type. List Of Hartley Vining working all week. Non -toxic. non-In- University flammable. Acoustic Research 2. With this calendar you can speed For TV. radio and Components Janssen up your work. For example, you can F M use. Wharfedale NO -NOISE Eco - USL Citizen Band start a job on the 7th and get it back nomical I- icraffer VOLUME CONTROL -a lit- For A Gonset al on the 6th to the customer who knew and CONTACT tle does Texas Crystals RESTORER a lot. Concertare his set was broken down a month ago Cleans Lubricates Bell G.E. Protects Package but wants the job clone yesterday, once Not Carbon Tet II cm. Weathers Solution Aerosol Harman- Koráon he makes up his mind to call you. Can Bottle SpanCan Quotation Elco Pilot 3. Saturday is usually a busy day Acrosounc $100 $225 $325 Quad Ampl b Spkrs' so this calendar has two of them and Dual C'tanger Net to Bogen Leak they are early in the week so you can Servicemen Dynakif Fis her do a lot of work before getting tired. H. H. Scoff 4. You'll note the calendar has no WE WON'T BE ThorensSherwood 1st, 10th or 15th so you won't have to UNDERSOLD! Pentron Roberts AtJobbers your Ampex DeWald pay those pesky bills, taxes, etc., that FREE Sony Tandberg are due on those days. All merchandise is Challenge.- 5" PLASTIC brand new, fac- Wollensak 5. You will note, too, that the 13th tory fresh & guar- Garrard anteed. Miracord is always on a Friday and, since Fri- EXTENDER Glaser -Steers 111 -F, ('ntrdosl -K day the 13th is unlucky, you just stay Push Button A.r,nibly Fr Rek -O it For P,n -Po,nt Applications Components in bed all that day and stay out of Dv... Not Cause Shorts Norelco trouble. Fairchild AIREX Pickering Gray We are sure that anyone with a good ELECTRONIC CHEMICAL CORP. Audio Tape imagination will discover many other Magnecord RADIO Artisan Cabinets great advantages to this calendar and P.S. Be Ask Rockford Cabinets I Sure To For CORPORATION that it will soon be adopted. 6 e =. NO -NOISE Can From the NATESA Scope RUBBER COAT Spray 64 -RE Cortlandt St., N.Y. 7, CO 7.2137

NOVEMBER. 1960 123

www.americanradiohistory.com Get the best in Electronics For today's enjoyment For Christmas giving For year 'round pleasure Send for Radio Shack's

F R a screwdriver BATTERY REMINDER or similar tool to pry Electronics CATALOGS Because of the small current required, the cap off, you are likely to damage the average multimeter will continue to the cap. A guy -wire ring screwed into work even after the internal battery the cap as shown makes a dandy may have started to leak and corrode corkscrew to help you pull the cap off nearby components. easily even though it might be stuck.- After losing one expensive meter this John A. Comstock : way, I formed the habit of taping a note HANDY HOLDER on the face of the instrument every A small corrugated cardboard box time I replace t the batteries. Mine say: with a double rim at the top will be c N p6. "Replace Battery Dec. 25," or whatever found to be extremely useful in making elate is a safe 6 months from installa- TV ¡ e. repairs or adjustments. The tubes s .` sas tion.- IVillinni E. Bentley \It CORKSCREW FOR TIGHT CAP 10!: WW040114IOW' M W a'r Many plastic insulating tool -dip con- ss.uuw°. tainers have plastic plug type caps that are very difficult to remove. If you use

Mail coupon for latest free 192 -page Radio Shack catalog plus every new issue for full year. * can be removed from the radio or TV and prongs See world's largest their easily speared into the line of electronics "sockets" of the double thickness of items: Hi -Fi, Ham Radio, Stereo, like the corrugated cardboard. They may values shown below. be placed in the same relative position * as they are in the TV and, of course, Buy on Easy Budget terms, up to 2 need not be marked. The interior of the years to pay. Money -back guarantee on every item always. Now -24 -Hour Tuner Service TVPICAL VALUES IN Tarzian Offers 24 -hour RADIO SHACK CATALOGS Direct Factory Service on TUNER REPAIRS

All Transistor 7.5 FM -AM Stereo u Pocket Radio Tuner $59.50 $8.50 ... $8.88 ..

TARZIAN tuners received one day will be repaired and shipped out the next. 1 '. increase in i No price: $8.50 per unit and $15 for UV combinations. That in- \ 111 cludes all replacement parts, and a 6 -month warranty against 4r1 i defective work- j manship and parts failure due to normal usage. Tuners repaired on approved, 3.98 & 4.98 Ste eo Duo R mote Control Records Each $1.00 Speaker $3.98 open accounts. Replacements available at low cost on tuners beyond practical repair. RADIO SHACK CORPORATION Tarzian -made tuners easily identified by this stamping. When inquiring 730 Commonwealth Ave., Boston 17, Mass. about service on other than Tarzian -made tuners, always give tube comple- ment ... shaft length ... filament voltage ... series or shunt heater ... IF MAIL COUPON NOW frequency ... chassis identification. And, allow a little more time for service Radio Shack Corp. Dept. 601.10 ll on these tuners. Use this address for fast, factory repair service; 730 Commonwealth Ave., Boston 17, Mass. ' SERVICE MANAGER TUNER DIVISION Dept.0 Send latest Electronics Catalog plus every new issue for one year, FREE.

Name I bloomsngton!nd ana S R E S R I I I Address A K T A Z A N N C echson 2-7251 Postoffice Lor City Zone State J Mfrrs. of Tuners. Semiconductors. Air Trimmers, FM Radios, Audio Tape, and Broadcast Equipment 124 RADIO -ELECTRONICS

www.americanradiohistory.com box is useful for small parts, extra Buy several lengths of small- diameter tubes, etc. By cutting down the height copper rod and an inexpensive die to of the box you can make the necessary cut the thread used in the tip end of double thickness rim for it from the the heating element of your iron. Clip material you trim off. -Glee F. Still - off a length of rod to suit the -lob, run a well thread 1/4 inch long on one end and file PLASTIC the other to the tip shape best suited to TOOL HOLDERS the joint being soldered. Empty metal wire spools can be used An added bonus arises from the fact as tool holders. The spool shown is a that the longer tip also radiates more 4 -inch type with 61/2 -inch diameter heat to the air, and thus provides a flanges. slightly gentler tip for delicate printed - By removing the top flange, an ordi- circuit boards.-Benjamin Ycltilt SERVICE BENCH :All) In the course of servicing electronic equipment, line power is often connected and disconnected many times. Most CASED service technicians do this by with- drawing and inserting the line -cowl plug. This soon becomes a nuisance as the plug usually falls to the floor when it is withdrawn. Using the power switch on the unit being serviced sometimes opens only one side of the line which doesn't completely isolate the unit from the power line. I solved this problem by making an 'LYTICS ac outlet control board and mounting it next to the ac outlet on my service bench. This control board includes a dpdt switch, pilot light and circuit breaker. With a flick of a finger, I can BY nary two -cel, flashl_gid will fit into the spool. The remainirg flange can be o attached to the shop wall with the O o O o flash lamp extending outward. -H. o AEROVOX CUSTOM TIPS SERVICE BENCH Low -wattage pencil CONTROL BOARD AC OUTLETS type soldering (FRONT) irons are handy, but every so often their Small in Size! relatively short tips may not penetrate o I00K far enough into crowded chassis corners. Since most of these irons have screw -in 117 VAC SI tips, it is easy to make your own o special 1 tips at low cot. 5 AMP CKT BREAKER NE-5I For 1960 It's ... 1 tools by Designed especially for wide appli _ :: ons

transistorized circuitry and cramped = pion

assemblies, here is a truly miniature . rolytir ei tubular that will handle full sized loads Aerovox Type PTT -PWE units feature "P llycap" plastic cases that are the next best hing to metal cans for maximum protection agaiist hu- midity. Advanced construction techniques assure for the long capacitor life. Electronics Service Trade Available in voltage ratings of 3, 6, IC, 12, 15, VDCW in a HK -17 Hex Key Set 25 and 50 wide range of capazitance values from 1 to 500 mfd. Units are rated for op- "Compact" in Size: $1.00 net eration at temperatures from -30 °C tc +65 °C. they fit the pocket ND -141 Combination Available for "off- the -shelf" delivery from your DE -810 Double Nut Driver Screw & Nut Driver local Authorized Aerovox Distributor. See $.79 net $.79 net your dis. "Compact" in Price: tributor today for all your Aerovox capacitor they- fit your requirements. SP -19 Probe pocketbook too AN -2 Tester $.96 net $.79 net Ask Your Parts Jobber or AEROVOX Your Jobber Salesman PK -8 Nut Driver A -86 Pencil Type Driver $.48 net $.60 net CORPORATION DISTRIBUTOR DIVISION VACO PRODUCTS COMPANY, 317 E. Ontario St., Chicago 11, Illinois -TS In Canada: Atlas Radio Corp., Toronto 19, Ontario NEW BEDFORD MASSACHUISE

N O V E M B E R , 1 9 6 0 125

www.americanradiohistory.com completely disconnect the unit being serviced from the power line. The pilot light indicates when the power is on, and the circuit breaker will prevent RADIO HANDBOOK blowing the main fuses should there be BARRY'S a short in the unit being serviced. the comprehensive The circuit and details of the control *GREENSHEET reference source board are shown in the diagram. I found VALUES it practical to construct the control ARE OUT OF a problem solver for board on a 4 -inch square of aluminum. THIS WORLD... Needless to say, this unit has made designers and servicing much faster and safer. - builders of radio Albert J. Krukowski equipment TIGHTEN SELF- TAPPING * A complete catalog of specialized industrial Gives simplified theory on practically every SCREWS Electronic TUBES and COMPONENTS . . featuring Barry Electronics savings to Indus - phase of radio. Tells how to design, build, When a self -tapping metal screw try, Servicemen and Experimenters. and operate the latest standard types of continues to turn as you attempt to We have thousands of tube types in stock. First radio transmitting and receiving equipment. tighten it, flow some solder into the Quality at Sensible Prices. Buy with confidence. More "How -To- Build" articles than any Prove these values to yourself! Complete and mail book in the field. the coupon below for your copy of the *Greensheet. \\ .11 also pun, hand your equipment and unused All information is original, up -to -date, and 'i Send details: BARRY ELECTRONICS CORP. complete. 800 pages of data, clearly indexed, 512 Broadway, New York 12, N.Y. Dept. REM covers Please soul owe a copy of the *Greeunhcet anti between hard -the largest RADIO add my n:n u, to p"ur mailing list. HANDBOOK ever published.

iltl ?tlq Nance Title

Company

Address

City State

PACKAGE HI FI screw's threads. When you put the or SINGLE COMPONENTS your distributor 7.50 -at screw back in, the heavier solder - You'll find our prices low EDITORS and tinned threads will and service fast. make the screw ENGINEERS, Ltd. anchor firmly again. -Alan C. Johnson Write for our quotation Summerland 5, California CENTER INDUSTRIAL ELECTRONICS, Inc. ATTRACTIVE PANELS 74 -R Cortlandt Street, New York 7, N.Y. Professional- looking panels for home - built equipment are easy to make from white Formica, often used on table and WANT RESULTS? counter tops. Available in small pieces at hardware and lumber stores, this -you'll get them with classified advertising in RADIO -ELECTRONICS material is dirtproof, scratch -resistant and easily worked with ordinary hand Opportunity Adlets tools. The smooth white surface gives Only 50c a word. See details P. 134. the equipment a modern look and takes black decal lettering for easy control identification. If shielding is a problem, mount the Formica panel directly over a regular ELECTRONI metal panel or simply back the plastic s panel with aluminum foil. - William E. Bentley Engineering- Technicians PLASTIC RUBBER Bachelor of Science Degree, 30 Months CLEANS FILE Save Two Years' Time The electronic hobbyist will find that Duro plastic rubber does a good job of Radio -Television Plus Color Technician (12 Months) removing Electronics Technician (12 Months) filings of solder, brass and Industrial Electronics Technician (12 Months) aluminum from a fine -cut file. The Electronics Engineering (B.S. Degree) Electrical Engineering (B.S. Degree) Mechanical Engineering (B.S. Degree) Missile headed Civil Engineering (B.S. Degree) for outer Architecture (B.S. Degree) space. Cour. tesy of Space Heald College ranks FIRST West of the Technology Mississippi in "Who's Who in America" Laboratories, Inc. Approved for Veterans DAY AND EVENING CLASSES U.S. Air Force Photo Write for Catalog and Registration Application. New Term Starting Soon. HEALD'S Your Name plastic rubber (available at hardware ENGINEERING COLLEGE Address Established 1863 stores) is applied to the file and allowed City to dry. Then it is peeled off. The filings Van Ness at Post, RE adhere to the sticky rubber and are San Francisco, Calif. State removed from the file teeth. -Charles A. CunningltoIn ENI) 126 RADIO -ELECTRONICS

www.americanradiohistory.com riIw\I GIANT 1961 204 PAGE LITERATURE CATALOG

elf SAVE UP TO 50% ON 8-A Any or all of these catalogs, bulletins, or periodicals are available to you on request SELECTED direct to the manufacturers, whose addresses are KITS listed at the end of each item. Use your letter - head-do not use postcards. To facilitate identi- fication, mention the issue and page of RADIO - ELECTRONICS on which the item appears. UNLESS OTHERWISE STATED, ALL ITEMS ARE TOP VALUES GRATIS. ALL LITERATURE OFFERS ARE VOID 1961ANNUAL CATALOG eat AFTER SIX MONTHS. IN POWER AND NAND ELECTRONICS CATALOG. 414 pages TOC'LS list over 40,000 items. 240 pages of rotogravure.-Allied Radio Corp., 100 N. `HIIII Western Ave., Chicago 80, Ill. Ht -FI AND SEMICONDUCTOR PRODUCT GUIDE STEREO contains transistor classification charts SYSTEMS & for audio- and radio- frequency and com- COMF0IJENTS putor and switching service for ger- manium alloy -junction types, power - 11111111 switching and amplifier applications for silicon diffused -junction types, and sili- 3. PAGES con rectifiers. - RCA Semiconductor RADIO TV OF BARGAINS Products -Distributor Sales, Harrison, NOT IN ANY N. J. OTHER CATALOG "JENSENEEDLOG" lists in its 12 pages ELECTRONICS 800 types of special -shank phonograph needles and their matching cartridges WO'S OF by a cartridge -number to needle- number NEW ITEMS reference section. Supplements Jensen's HERE large needle wall chart.- Jensen Indus- LISTED tries, Inc., 7333 Harrison St., Forest FOR 15T TIME

Park, Ill. CITY 6, MO. I I 117 E SI. KANSAS BYRSTEtN-APPLEBEE "' -1 Mt MOLDED -CABLE ASSEMBLIES for the BURSTEIN- APPLEBaE CO. Dept. RE industrial electronics industry appear in 1012 -14 McGee St., Kansas Cif), 6, Mo. I the 4 pages of Catalog M -701. A guide Send Free 1961 B -A Catalog No. 611 for engineers, it lists engineering con- 1 1 siderations for standard assemblies and 1 RUSH COUPON NAME 1 illustrates those most commonly used. 1 -Switchcraft, 5555 N. Elston Ave., Chi- TODAY! I ADDRESS 1 cago 30, Ill. CITY STATE 1 FUSES of the small -dimension nonin- dicating and indicating type for air- LOW craft, electronics, instruments, appli- Unbelievable PRICES! ances, industrial and automotive use are NOT KITS ... But Factory Wired and Guaranteed outlined in a new 12 -page catalog. - Sightlnaster Corp., 50 Aleppo St., Provi- HIGH QUALITY INSTRUMENTS dence, R.T. New! Model B -45 ! TC -75 Unja. I:cnbinali TV AND Radio & TV FM TUNER Catalog Too pre- TEST SPEAKER & sents their uses, features, specifications, SIGNAL mounting SIGNAL TRACER dimensions, terminal connec- GENERATOR tions and installation instructions for Plus resistor teste Provides highly Phis condenser te, er the company's line of tuners.- Sarkes- stable signal. Gen- Piss output indicator Tarzian Inc., Tuner Div., Bloomington, erates R. F. fre- Plus speaker substitution Plus resister snbstitutor quencies from 150 Plus substitute 100 V D.C. power supply Ind. Kilocycles to 50 Plus field substitutor. Pian condenser sub itutor Megacycles. (150 Kc. to 12.5 Mc. on Fun- Plus voice coil substitutor STEREO is defined and explored in damentals and from 11 Mc. to 50 Mc. on Plus signal tracer Stereo and High Fidelity with emphasis Harmonics). R.F. is obtainable separately Plus universal output transformer on live or modulated by the Audio Frequency. Plus experimental one stage audio amp]iter broadcasting, discs and tapes, Measures 7,V4" x 7s/," x 5 ". Weight 8 Lbs. Measure, 7" x 11" x 5 ". Weight, R t s. stereo systems using various combina- Complete -only $14.95 Complete-only $19.95 tions of component setups, design prin- .Order N.Y ciples of such components and conver- directly from METROPOLITAN ELECTRONICS 106 Fifth Ave., New `for* 11,

NOVEMBER, 1960 127

www.americanradiohistory.com sion of monaural equipment to stereo operation. 4 -page booklet includes easy - EMC to -read diagrams for each setup and phono cartridge section. -Eleotronic In- strument Co. Inc., (EICO) 33 -00 North- ern Blvd., Long Island City 1, N.Y. HOME STUDY, its advantages, the proper choice of a school, state regula- SCHOOL tions and restrictions, contracts and ad- ditional sources of guidance are consid- ered in Facts You Should KHU1r' Aburrt Hoare Steely Sel,uols.- Retter Business DIRECTORY Bureau of Metropolitan Boston, 52 Chauncey St., Boston 11, Mass., 15e CAR RADIO troubleshooting is taught in Guide. to Noise -Free Car Radio In- stallation. How to find and cure the By far the BEST VALUE obtainable in source of motor noise is described and either wired or kit form ... compare and illustrated with photographs and dia- SCIENCE grams. Booklet closes with suppression you'll agree 11THE BEST BUY IS EMC." ENGINEERING and installation accessories. -Motorola Rl1CHItOR'S IN Consumer Products, \,.. DEC.REF 27 OR 36 MONTHS Inc., 4545 W. Aug- t I

1 usta Blvd., Chic;ltro 51, Ill. 50¢. Furt 2 Ind RECORD SELECTION is just one of the subjects in the Art of Selecting, Play- INDIANA TECHNICAL COLLEGE ing and Preserving Records. The 20- page booklet also offers the layman GET INTO guidance in musical etiquette, preserv- ing recording fidelity, the role of the ELECTRONICS V.T.I. training leads tu .uses cartridge and stylus and the practical te,I,niclann, field ngineers, special- EMC Model - 211 Tube Tester - The smallest, lowest ists in communications guided min. priced, made and decorative aspect hi -fi .Iles, cmnputers, radar and summation. domestic tube tester on the market. It is of and stereo II:ISIc :m,l advanced courses in theor, completely flexible and obsolescent proof. It checks nd laboratory. Assoc. degree in eler- systems in the home. -Shure Brothers s ,nh In 211 I . N.V. In electronic each section of multi -purpose tubes separately, checks nglneering obtainable. ECM) a. all octal, loctal, 9 prong and miniature tubes for shorts, Inc., 222 Hartrey Ave., Evanston, Ill., ...ailed. I;.t. approved. Graduates In ,II l-ran,he', of electronics with mph,. leakages, opens, intermittents as well as for quality. 250. ,ah'.. Start February. Seplemb,', Quality is indicated directly en a two color meter dial norm,n'I .-a I,'I HI %. nigh School grad.... using the standard emission test. Comes complete with FALL AND WINTER CATALOG, 1960 -61. II. .,,t. '-talOg. instructions and tube charts in ring bound manual. VALPARAISO TECHNICAL l1 Heathkit hi -fi components, from Size 63/4" x 51/4" X 21/4" deep. Shipping weight: 3 lbs. pickup INSTITUTE Wired $22.90 Kit 14.90 or tape recorder to loudspeaker. Marine, Dept. C Valparaiso. IrIJ:. i CRT Picture Tube Adapter $ 4.50 test and wired equipment. Amateur ra- dio gear. Science kits. 83 pages. Illus- trated. - Heath Co., Benton Harbor, Mic,. ENGINEERING MASTER RADIO AND TV SET INDEX to service manuals, from the old Atwater HOME STUDY COURSES Kent and Majestic through newest 1960 radio and TV sets. -Supreme Publica- RADIO Courses written by world ELECTRONICS Ía tions, 1760 Balsam Rd., Highland Pk., TELEVISION Ill. 25e. authorities in all branches of CIRCUIT engineering and science and MATHEMATICS TRANSISTOR HOME -STUDY COURSE ELECTRICAL ENG. EMC Model 109 - Volometer- Features 20,000 OHMS proved successful by thous- TELEPHONY volts DC sensitivity and 10,000 OHMS per volt AC sen- revised for 1960 transistor devices anal ands of our graduates. One CIVIL ENG. sitivity. Uses a 41/2, 40 microampere meter, with 3 AC applications. 10 SURVEYING current ranges, and 3 resistance ranges to 20 megohms. lessons cover simplified hour each day in your spare ARCHITECTURE 5 DC and AC voltage ranges to 3000 volts and 3 OC basic semiconductor theory with practi- time will start you off to higher FORESTRY current ranges; also 5 DB range. cal experiments and ses-vice techniques pay, security and prestige. MINING Model 109 - With carrying strap, Weight 2 lbs 5 ozs,; STRUCTURAL Size: 51/4" x 6214" X 27/e" $26.95 for amplifiers, oscillators, rectifiers and Personalized instruction MECHANICAL ENG. Model 109K - Kit Form 19.25 deflection circuits. -CBS Electronics, methods ensure rapid pro- INDUSTRIAL ENG. Model HVT - 30,000 Volt Probe for Model 109 7.95 & MANAGEMENT 100 Endicott St., Danvers, Mass. gress. Fill in the coupon and REFRIGERATION indicate the course of interest. DRAFTING CATALOG No. 96. 19.2 pages carry We will send a PLASTICS you complete AERONAUTICAL over 30,000 electronic, hi -fi and hobby outline of the course and a ENG. items. Profusely illustrated. 3 -page booklet describing the Institute HIGH SCHOOL CHEMICAL index -Radio Shack, 730 Commonwealth and our advanced teaching MATHEMATICS Ave., Boston 17, Mass. methods. JOURNALISM ACCOUNTING HOME HI -FI, both stereophonic and monophonic, is considered in Sterronles- MAIL THIS COUPON TODAY tcr High Fidelity Components for 1960 EMC Model 107A - Peak to Peak Vacuum Tube Volt - Ohm Capacity Meter - 6" meter cannot burn out - and its companion booklet, Hon' to Use entirely electronic. Measures peak to peak AC voltages ist CANADIAN INSTITUTE OF SCIENCE b TECHNOLOGY LIMITED ranges. Stereo High Fidelity Components to 2800 volts in 6 Measures capacity in 6 758 Century Bldg., 412, 5th St. N.W., Wash., D.C. ranges from 50 mmfd to 5000 mfd. Measures resistance Your Decorating Plans. -H. H. Scutt, in 6 ranges from .2 ohm to 1000 megs. Measures DC 111 Powdermill Rd., Maynard, Mass. NAME volts to 1000 volts in 6 ranges. Input resistance to 16.5 megs. Wired $51.40 Kit $36.50 RECORD CHANGERS SERVICING ADDRESS GUIDE in 2 parts (I for the manufactur- Yes, tell me more, send me FREE a detailed er's VM changer and II for his BSR CITY STATE catalog of the Complete EMC Line. Dept.ME -116 changer) describes the equipment, its COURSE OF INTEREST NAME step -by -step assembly and the handling Canadians: Send to CJ.S.T., 759 Garden Bldg., STREET of possible repair problems, with the 263 Adelaide St. West, Toronto, Ontario. CITY STATE help of detailed drawings and exploded Measurements Corp, Iuuauuuuuu E525 views throughout. -Motorola Consumer E M C B'wlectronicay , , N. Y. Ex. Dept., Pan-Mar Carp., 1270 B'way, New York 1, N.Y. Products Inc., 4545 W. Augusta Blvd., sw ------d.- ell Chicago 51, Ill. 500 each. END 128 RADIO -ELECTRONICS

www.americanradiohistory.com prepare for your career in SCHOOL ELECTRICAL DIRECTORY ENGINEERING LEARN RADAR MICROWAVES EDUCATION O, Age Ll COMPUTERS -TRANSMITTERS ENGINEERINGfor the Space ELECTRONICS CODE TV RADIO NORTHROP INSTITUTE Of Technology is in 1,atel endnued, nonprofit college of erlgineef ing ulrering Phila. Wireless Technical Inst. 'r ssi tY EAR vr.rediled technical In,l ittue curricula and 1533 Pine St., Philadelphia 2. Pa. eouiulele Bachelor of Science degree poor r:un +. Students sue - A Non - Profit Corp. (cent 3u many foreign counlrirc Outhtandingb' and COMPUTERS Founded in 1908 eesVUl gtadnates etitnIMed In aeronautic,, elertnmies. Writs Indav for catalog --nu obligation. Write for nee Catalog to Dept. RE -11 space i,,IHrology. Classes now forming NORTHROP INSTITUTE OF TECHNOLOGY 1181 West Arbor Vitae Street. Inglewood I. California RADIO -TV At MSOE, you can equip ELECTRONICS engineering degree in 27 months yourself for a career rh :u,e.. for 'r nett., I lie. Ranh! uth' J1 11 ome. 13A('H2't.0R OE DEGRE'11 IN 27 in many exciting, grow- PREPARE FOR A GOOD JOB! MONTHS In Elect. IEleet,nlce or Power major,. t. lero., (Item.. Engineer Ing. IN 36 MONTHS In ing fields: MISSILES BROADCAST ENGINEER Itnn111r'su Administration It :ener'li I Ruslness, Arctg.. Motor r.ttepurt Sint. majors). Small rlaeses. More pruf.seInnal RADAR AUTOMATION ui RADIO SERVICING AUTOMATION tiros linon.. well.egulpped I:rhs. ra,n¡nls. I)orn,s. Modest costs. Year round operat ion. Foundedl IHxJ. Enter RESEARCH DEVELOPMENT .Ian.. Mar.. duly. Sept.. Write Director TELEVISION SERVICING of Admission.. for Catalog and "Your Career in ELECTRICAL POWER mn .ind Commere Book. BLACK & WHITE -COLOR ROCKETRY 241IO College Ave. AVIONICS COLLEGE Angola, Indiana APPROVED POR VETERANS AND SURVIVORS When you from OF VETERANS graduate BUILDING AIR CONDITIONED the Milwaukee School SEND FOR FREE LITERATURE you AT LAST! A of Engineering, are INSTITUTE home study course cover- for BALTIMORE TECHNICAL ing all phases of electric prepared a dynamic 1425 EUTAW PLACE. EALTIMOEE 17. MO. and electronic career as an Electrical organ servicing. Engineer or Engineer- A NEW COURSE An extensive ing Technician. Under course covering a faculty of specialists, every make of organ -repair, regulat- you gain a sound TRANSISTORS ing, and troubleshooting. technical education in explained in 32 pages of modern, completely BJ/LHORI[ terse copy and modern equipped laboratories illustration. Invaluable to ORGAN SERVICING and classrooms. As a Service and Installation result, MSOE graduates.. Technicians and Students. are in great demand Your Available at $1.25 a copy. Opportunity To Get Into A and highly accepted by 10 copies or more 51.00 New, Rapidly Expanding Field At industries nationally. each. Special rates to The Start. Don't Miss It ! ! At MSOE you will schools and business firms. meet men from all WRITE NOW NILES BRYANT SCHOOL walks of life and all saedi unlimited FOR FREE Dept. E., 3731 Stockton Blvd. parts of the country BOOKLET Sacramento 2A, California some fresh out of 626 SOUTH FEDERAL STREET high- school or prep CHICAGO 5, ILLINOIS NHSC Approved The Pioneer School school, others in their Established 1898 twenties- veterans and non -veterans. ENGINEERING COURSES You can start school in any one of E.E. four quarters and begin specializing Option Electronics or Power Mechanical. Civil IL Physic. immediately. Engineering technicians Also in Liberal Arts ELECTRONICS graduate in 2 years with an Associate presented through in Applied Science degree. For a HOME STUDY rREE! Bachelor of Science degree in Engi- Resident Classes Also CAREER KIT neering, you attend 4 years. A 3 -month PACIFIC Available if Desired NT(.RNATIONAL PACIFIC INTERNATIONAL preparatory course also is available. COLLEGE OF ARTS A 3, SCIENCES I into a J If you're interested in breaking FREE CAREER BOOKLET! Primarily a correspondence senor( good -paying job in Radio -TV- Electronics, If you're :aYerested in any absolutely free a 5719 -M Santa Monica Blvd. Hollywood 38. Calif. I. C. S. will send you phase of elect renics, radio or 3 famous booklets famous Career Kit with television, be sure to look that have helped thousands of others - just like yourself - on the road to real into the programs of study success. Includes: offered by the Milwaukee School of ?agineering. Just 1 "HOW TO SUCCEED" Career Guide - Learn Transistor mail the cope,. 1 36 -page gold mine of career tips and information. Electronics At Home! "JOB CATALOG" of opportunities in 2 your field of interest. MILWAUKEE SCHOOL Prepare now for a profitable "SAMPLE LESSON" (math) to demon - 3 strate the famous I.C. S. method. l .freer in this growing field. Learn OF ENGINEERING Kit theory, construction and appli- Send today for your free I.C.S. Career Dept. RE -1160, 1025 N. Milwaukee St., with these 3 famous booklets. There's no Milwaukee, Wisconsin cations of all types of transistors obligation. This may be the big break with this proven home -study you've been waiting for. Mark and mail ('lease send FREE Career Booklet. I'm course from the Philco Techno- the coupon today. interested in Electrical Engineering; logical Center. ri Electronics Computers INTERNATIONAL CORRESPONDENCE SCHOOLS 1 Electrical Power Radio -TV LI Mechanical Engineering. FOR FREE INFORMATION Dept. 37683K. Scranton 16, Panna. PLEASE PRINT PLEASE WRITE TO: Please send free Career Kit with S famous booklets O General Electronics Radio -N Servg í Practical Electrician Name. Sga Industrial Electronics O Sound (quint. Servg C: Profess I Eng. (Elec.) Radio -TV Ent! r'g Electrical Entire Electrical Drafting Address_ PHILCO Electronic Servicing O Electrical Tech. Other City_...... _... . _..._...... Zone...... State ...... _ ...... Name Age _ TECHNOLOGICAL CENTER El I'm eligible for veterans education benefits. "C" and Ontario Ses., Philadelphia 34, Pa. Address MS -123 City State J NOVEMBER, 1960 129

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Available 354 .68 6L6 1.19 12507 .89 35T 4.00 description of receivers, transmitters 3V4 .83 654 .59 125147 .89 lOOT 7.011 from Diamond Television Ltd., 8636 Bir- 5R4 .98 858 .99 12517 .75 316A 5 /$1. and test equipment to help make an 5U4 .59 65Á7 .69 12567 .94 388A 3/$1 nam St., Montreal 15, Canada. 5 x 9 in. 5V4 89 6587 1.19 12507 .84 4168 16,00 $4. intelligent choice. Prices and specifica- Wanted S,lrpme electronics fro.,, school..- r 384 pp. 5Y3 .59 6SC7 .89 19806 2.15 450T 42.00 tions are listed. -IQ 6AB4 .59 6507 .79I19T8 1.18 807 1.00 An extremely useful handbook for 6AC7 .70 6SH7 .69 25806 1.39 809 3.00 6867 .89 6SJ7 .69 25L6 .69 811 4.40 those who deal with foreign tube types, GLOSSARY OF TERMS IN COMPUTERS 6AH6 .91)í65K7 .72 25W4 .77 812 3.00 AND DATA 6AK5 69'' 65L7 .89 25Z5 .83 813 11,00 the directory has an introduction in 10 PROCESSING, by Edmund C. GALS 2/51 6567 2 /$1 25Z6 .75 814 3.45 Berkeley 6/105 .63 6507 .74 EL34 3.49 815 2.75 languages and from there on and Linda L. Lovett. Berkeley 6AS7 ;1.011 65R7 .79 EL37 2.49 826 .59 uses only Enterprises, Inc., 815 Washington 6A76 Iir.6T8 .98 35L6 .69 8296 8.00 the international language of electron- St., ))'onod a04 TL tube.) Ton a S 8 Paid Newtonville 60, Mass. 51/4 x 8 in. 90 6AU4 1.10 6U8 .98 35W4 .49 832A 7.00 pp. 611115 1.19 6V6GT .70 35Y4 .69 866A 2.75 ics. It's divided into seven color -coded $3.95. 6AU6 1i 6W4 .79 3525 .63 1625 5/51 6AX4 1î)I 6W6 .89 50A5 .69 6146 4.00 sections according to tube classification Over 870 terms and ideas in 6BA6 9 6X4 2/$1 SOBS .69 5879 .98 the 6BA7 1.110 6X5 .49 5005 .69 5881 2.711 and contains basic data on a large 68D6 .69 6Y6 .07 50L6 .69 6550 3.90 fields of computers, logic, program- 66E6 .59 7N7 .89 KT66 3.29 5654 1.00 number of European 6606 1.50 12AL5 .59 75 .89 5894 12.00 and American ming, etc., are listed and defined. Mean- 68X6 .72 12AQ5 75!80 .59 7193 111 /81 types, showing each one in a basic cir- ings are TUBES made clear so that beginners WANTED! WE BUY! SELL & TRADE! cuit diagram. An eighth section covers can understand them. NEW POWER CONVERTER transistors. 12VDC to 500VDC up to 200Ma 100 THE MOBILE MANUAL FOR RADIO AMA- Watts: Tap t 2SOVDC Type C1250E SO $35. Ili ..0}c1en '). In' tipple, low hilt YOU WANT TO BE A HAM (2nd edi- TEURS (2nd edition). American Radio current - Silicon rectifiers! Tnroldial tion), by Robert Hertzberg, Relay League, W. 11111ff! ,nog -metai tape 1)d 0,111, '01'111- W2DJJ. Hartford, Conn. 61/2 x in. t'u.ed .ohurt circuit proof, s mill Howard W. Sams & 91/2 luisize! Quiet! Light weight! CI 251 itll'I Co., Inc., Indianapo- in. 282 pp. $2.50. t ready to go. Outset-,I> lis, Ind. 51/2 x 81/2 in. 188 pp. $2.95. 12VD 250 T ï.i r' Llors Heavy í',1p1 l :19. I. The mobile ham will find here the 12YI1C'to n'. 2.01'1 up Lo 10Ú51A Type t'1 "2..-i.\ .x:10. You will want to refer to this book information he needs to make and use TRANSISTORS & ACCESSORIES before and after you get your ticket. the latest and best in receivers, trans- 214 I I 1 $3. 2N 142 54.50, 2N277 $4. 2N278 $5. $1.39. 2N179 51.80, 2N177 $1, 2X178 It tells where to apply, how to learn mitters, converters, etc. Practical tube $1.75. 2X2 I7 51.50, 2N255 $1.20. 2X270 5.95. 2X27.1 51.25. "N 918 5.80, 2X54) $1.20, 2X578 the code and what the requirements and $1.80, 2X .-9 $2.20, 2X581 $1.25. 2X582 $2.10. transistor circuits are represented. 2N174 58.50. 2\113 $6.50. are. In an interesting manner it tells DIAMOND BASE MICA MOUNTING KIT 5 .30 They range from the simplest to the DELCO ROUND BASE MICA MOUNTING KIT .30 DELCO POWER HEAT SINK WITH FINS .75 you what hamming is and how to oper- most complex, all described in detail ate your station. It does not cover the with photos, diagrams and construc- "TAB" KITS! "TAB" THE BEST KITS! "TAB" All K,), Contain Most Popular l'alu,..t theory portion of a license exam, so tion data. Kit 2 Eng. Parallel Rules Kit 5 Sub -Min Tubes Kit 35 Precision Resistors Kit 40 Standoff Insulators radio theory must be studied from (Continued on page 134) Kit 10 Switches Kit 35 Power Resistors Kit 75 Resistors I/2/1/2W Kit 75 Mica Condensers Kit 150 Carbon Resistors Kit S Crystal Diodes Kit 25 Panel Lamps Kit 100 Fuses, Assorted Kit 12 Electrolytic Condss Kit 100 Ceramic Condsr. Kit 56 Tube Sockets Kit 10 Germanium Diodes Kit 65 Tubular Cond'sers Kit 5 FT243 Xtal Holders Kit 500 Lugs A Eyelets Kit 8 Silicon Diodes KILLER AT Kit 10 Bathtub Oil Cond'S Kit 5 Microswitches LARGE S SAVE Kit lbs. Surprise Pckg. Kit 4 Asstd Rectifiers 20% Kit 10 Xmttr Mica Condsr. Kit 2 PNP Transistors Muscular dystrophy dooms children to Kit 3 Phone /Patch XfmrS Kit 4050 Ft Hookup Wire Kit 3 Searchlights Kit 2 Veeder Counters early death. Kit Circular Slide Rule Kit 2- Computer ToroidS Help scientists track down Kit 12 Algtr Clip BUY Asst'd. High Gain XTAL Mike DIRECT Kit this killer by giving generously to the BUY 19 KITS-GET ONE FIEL!EACH KIT 990 You can now buy this MARCH FOR MUSCULAR DYSTROPHY "SUNTAB" Q1) BATTERY -SELENIUM PHOTOCELL SAP -Round 11/2 Dia. -250 ua $1.00 (OAP -ROUND 11a" Dia. VOXBOX at BIG SAVINGS ' " -360 $1.75 t - 15ÁP -ROUND 2" Dia. -750 53.00 *RECORDING TAPE 26P-750 á.a3/g x 7 16 *oxide 700 u;,, d)teed not to rut, u9 11 r squeak - or SBP -/-2 1-7/16 x money hack. Compare 011rS 0 ua 1.35 (( With other "Bargain" 100P -RECT. 1 -I1 16 o P/ -3860 a. 1.80 tape, l'nu'll find It's more KIT ALL SIX ONE EACH 7.00 than in.t "price" when ORDER QTYS.TEN OR MORE DEDUCT 200o you deal with us. We e This Item original pioneers in the Shipped Postpaid Orders S5 Up tape recorder bush-Lesssmd reputation n everything to us. NEW Selenium Radio & TV Rectifiers! GTD. 111)0' . .0'' tate l (plastic(. 5" .75 65Ma 45c, g 6 for $2; 100Ma 45c 12. 55; 9110' M31..19 (PUlyer teil, 5" .95 250Ma 650, 15 10/56; 300Ma 88c, 10 58; 12011' bll"I..tlt, t', noll, 5" reel 1.28 500Ma $1, 18 12011' 3.0.t:t t i)l:lstlrl, 7" 1.29 10/58, 25 518 t 2 Orders this Item $10 or More, Postpaid 48 States! 12011' SI) I Á I 1 . t Toil (strong) 1.95 Nt10PERSCOPk, '1'(1ßF 1800' .\ 11)00íl 7" 1.79 SEND FOR 18 )' 11Y1 .5 )1 I ) thick,k 7" 2.29 IN 49112 ß)l'ß 1:0111 1 0X0 Irsc tubes c __'$1.59$1.59 NIX) 7 !IVY DTY 11>l' 1.111 -1 "I- I.59X9 TWO for FREE CATALOG! )poo .191)t ll 7" 2.69 $9 2101 ' 1111.:\It. tensilized. 7" 3.49 * NEW "TEKSEL" SELENIUM RECTIFIERS Studios, Large Users Even Lower FULL WAVE BRIDGE RECTIFIERS. 1/.\" I: 1'15)1. '.Tit! AMP. 18VAC'36VAC 72VAC 144VAC CONT. I 14VDC'28VDC 56VDC I118VDC NORELCO LAMP IS 1.30 $ 2.00 $ 4.90'. 5 6.50 2AMP 2.15 3.00 6.25 12.30 A voice SPEAKERS 3AMP 2.90 4.00 8.60 16.75 -controlled relay device for voice- operated Fan 1)711111. " 6AMP 4.15 8.00 18.75 36.15 speaker, original list :11.' - i:,I 1OAMP 6.10 12.15 26.30 48.90 "break -in" with any voice modulated rig either NET 23.117, NOW. , iii., ith,;v last 1/2 Write for Complete Rectifier Catalog off net . 11.98 I.I)). ,nota)!,'. fixed or mobile. Gives you tremendous advantage (rll.s con Hausa .,.Irl'. Frtyuenry 40- 2)1,1100 cy. Other sFASA TOP in contest operating, traffic handling, telephone TIONAI. Speakereductions NEW SILICON 750MA' DIODES HATS type conversation and "two hands on the wheel" Prot 0r4 of GENERAL PURPOSE 400 PIV at 250 MA SENT) 1 ) )1 sl'P:AICKII .S'l'EI IFI)'.A- SPECIAL®9 25 FOR $8 mobiling. T1ON SHEET. COMMISSIONED ELECTRONICS CO. r s /piv rm/piv ms /piv ms /piv 1776 Columbia Road Washington, D. C. 35/50 70/100 140/200 210/300 0 DBecl 19c 29c 34c 43c $ 28äb rms/piv For 2805/040 35/50009 420/600 490/00 89e 95c Only rms/p m /ply rms/piv /ply Send check or money order to 560/800 830/900 700 1000 770/1100 Cof SPACE ? $1.05 $2 You bet we'd be.... U we were CAPACITORS$ INPUT DERATE 20?'0: TRANSCON DIVISION to tell you all about 's (47 or m,Te we polt p,.vn,in , .0, 1,, NORTHEAST TELECOMMUNICATIONS, INC. but of this World Hi Fi Values! TERMS: Money Back Guarantee! Our 15th year. $2 min. order Danbury, Conn. F.O.B. N.Y.C. Add shpg charges Virile for sr for C.O.D. 25% Dep. Prices "TAB" hown subject to change. Send for NEW catalog free audin 25 -E Oxford Road 111 -GP LIBERTY ST. , N. Y. 6, N. Y. Available from franchised distributors at slightly Catalog SC1i(( 5 fOT Catalog Massapequa , New York PHONE: RECTOR 2.8245 higher cost. 130 RADIO -ELECTRONICS

www.americanradiohistory.com LAFAYETTE'S 1961 CATALOG 324 GIANT SIZED PAGES The Complete Catalog Featuring "The Best Buys In The Business" \ l Stereophonic Hi -Fi Equipment L Pub,i:. Address Systems IQ Tape Recorders CQ Radio and TV Tubes and Paris Q Citizen Band Equiment l t Ana °eur Equipment

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CONTAINS HJN)REDS OF EXCLUSIVE LAFAYEITE ITEMS NOT AVAILABLE IN ANY O1bER CATALOG DR FROM ANY OTHER iOURCE SEND FOR YOUR COPY NOW! - EASY PAY PLAN -the simplest, and áuibkest way to ge. s -at you A "must ' 6cr the econom-1' minded hi -fi enthu- want when you want it. As little as $2 down ... up to 2' nonths siast, experimenter, hobo 'isi, engineer, techni- cian, student, serviceman a .d dealer. to pay.

KT -650 FM Tuner Kit Stereo Control Center 54.50 KT -602, Kit LA -6-n, Wired TE -15 Tide Checker 79..50 1 34.50 13,95

2 Communications Receiier R W 60 20,000 Ohms Per RK -400 -Speed Volt Multitester Portable Tape Rectifier K7-200, Kit HE -10, Wired 13.50 49.50 64.50 79.55

r Lafayette Radio Electronics Corn Dept. JK -6, P.O. Box 100 joFAYETTE Jamaica 31, N. Y. Z Send tme the FREE Lafayette 324 page R A a O 1961 catalog 610

Mail the coupon today for your Name _._-...._._....._...... _.- FREE copy of Lafayette Radio's 1961 catalog. Address_._...._.

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www.americanradiohistory.com a rieg NEWT! LAFAYETTE HE -15A Elt`'rnaagt Jry 2 -WAY SUPERHET Flennin.q i Pleasure CITIZENS BAND TRANSCEIVER!

Completely Wired -

NT "ILA Not Superregenerative but SUPERHET! POR EASY CRYSTAL ACCESEISILITY COMPLETE 2 -WAY COMMUNICATIONS FOR POSITION OAK ANTENNA ELECTOR BUSINESS, HOME, FARM, BOAT, AND SPORTS CONNECTOR

NOW WITH ADDED FEATURES R P INDICATOR Effective VARIARLE Full -Wave Variable Noise Limiter Five Prong Micro. 5750 NOISE LIMITER phone Jack For Easy Relay Addition RF Jack on Front Panel CONTROL R P JACK AND ONLY N ION CR VT 5 Transmitting Positions Tuneable Receiver Over Full 23 POWER INDICATOR CRYSTAL M OPNON Channels Planetary Vernier Tuning Complete with Trans. 5.00 Down misting Crystal for Channel 9 CITIZENS BAND - The New Two -Way Personal Communications Method for Every- conversion to a push -to -talk relay a cinch. RF lack on the front panel may be used one - Fill out the FCC form enclosed with each Lafayette Transceiver. No exami- to monitor the current in the final tube using external meter. nation or technical knowledge required - Any citizen 18 years or older is eligible Controls include a 3 position function switch (transmit, receive, and transmit with for a license. spring return), planetary vernier tuning plus variable noise limiter. Output imped- BAND ance matches 52 and 72 ohm antenna with Amphenol type coax connector. Has large THE GREATEST VALUE in the CITIZENS FIELD 4" PM speaker; input jack for crystal or ceramic microphone; power receptacle in Just think now you can have 2 -way radio communication ... economical, efficient rear for AC line and 6 or 12 volt external power supply. Supplied with single trans- from your home, office, store, auto, truck or boat literally hundreds of uses. The ... mitting crystal for channel 9, high output crystal microphone, and brackets for easy Lafayette HE -15A Superheterodyne Transceiver is both a compact precision trans- mounting of units in auto, boat, etc. Operates on 115 volts AC. Addition of 6 or 12 receiver on D mitter and designed to operate the new class "Citizens Band." Two or volt power supply (separately supplied) adapts transceiver, for mobile operation. more of these units furnish your own communications system covering up to a 20 SizK 101/nWx5V2Hx63/e "D. Tube completement: 2.6U8A/6EA8, 1.6A15, 16V6, 1.12AX7, mile or more radius depending on antenna height and terrain. 1.6ÁW8. Shpg. wt., 11 lbs. The Lafayette HE -15A meets all FCC requirements and operates much in the same HE -15A 5.00 Down Net 57.50 manner as police and other short-wave communications systems. The Transceiver POWER SUPPLY: features 5 crystal controlled transmitting channels operating at a maximum legal Adapts HE -15A for mobile operation. Complete with cable, 6 or 12 volt vibrator power input of 5 watts fully modulated, RF stage in both transmitter and receiver. and mounting flanges. Completely enclosed. Size 41/40x6Wx4 "H. Shpg wt., 4 lbs. The 5 position crystal selector on the front panel selects any one of 5 transmitting HE -16 For 12 Volts treouencies. These 5 crystals are readily accessible by means of a removable front Net 10.95 HE -18 For 6 Volts plate. The superheterodyne receiver is tuneable over the full 23 channel band with Net 10.95 3 watts audo output, AVC, and an amazingly effective Full -Wave Variable Noise TRANSMITTING CRYSTALS: For any of the 23 channels. Specify channel Limiter. The noise limiter is continuously variable from the front panel for diminish- or frequency. ing ignition and other unwanted noise pickup. A new 5 prong microphone jack makes HE -830 Net 1.95

SENSATIONAL LAFAYETTE CITIZEN BAND NEW! LAFAYETTE TELESCOPIC CITIZENS BAND 1 MOBILE ANTENNA WHIP ANTENNA

THE SCOOP BUY FOR CITIZENS BAND MOBILES Chrome Plated CHROME SWIVEL BASE Chrome swivel ball mount base designed to Telescopes From 161/2 to 40" PLUS be mounted on any surface. Stainless steel Mounts Vertically or Right Angle STAINLESS STEEL spring holds rod in properly adjusted position SPRING and prevents rod damage from shocks and An value. This high three PLUS outstanding antenna quality blows. Stainless steel whip for maximum resi- section telescoping antenna is designed for attachment 1021/2" STAIN. directly to your citizens band transceiver. Ideal for point LESS STEEL WHIP liency and strength. Shpg. wt., 4 lbs. to point service over short distances. Molded base load- FOR OPTIMUM 11 HE -800WX ing coil has a threaded stud with a PL -259 plug- connector METER Net 6.95 PERFORM- for vertical or right angle mounting. Shpg. wt.; 1 Ib. ANCE HE-19 Net 3.95

NEW! 10,000 OHMS PER VOLT MULTITESTER NEW! LAFAYETTE RADIO FIELD INDICATOR Outperforms Instruments Many Times Its Size Provides a Continuous Indication of Transmitter Output Rugged 200 ua Meter Movement Completely Portable Extra Large 31/2" Meter Face -Requires no Electricity, Batteries or Transmitter Connection. Completely Wired and Tested With this rugged, new radio field indicator you can check All Accessories Included performance of your marine, mobile or fixed transmitter . . . actually measures the RF field generated by any transmitter A convenient, pocket -sized instrument with an unusually sen- between 100KC and 250MC regardless of power. Features a sitive 14,000 ohms -per -volt AC -DC meter, 1% resistors, single 200 ua meter movement with a variable sensitivity control. range selector switch. First capacity range requires 120V AC, Phone jack at rear of Indicator accepts earphones thus pro- second range requires 6V AC. Durable Bakelite case and viding an aural check of transmitter output. Antenna extends panel; probes and flexible leads are plastic coated and color from 31/4 to 103/4 ". Powerful magnet on bottom plate allows coded. Complete with battery. 4''/,x3 %x11/8". Shpg. M., 11 easy mounting on car dashboard or metal surfaces. Use any. lbs. where ... requires no electricity or batteries. Dimensions: TE -10 Net 9.95 (less antenna) 31/eWx21/4Hx2"D. TE -14 Pigskin Carrying Case, shpg. wt., 8 oz Net 1.95 TM-14 Net 7.95 PLEASE INCLUDE SHIPPING CHARGES WITH ORDER AlEt.X11.A.:TirM9VT'30 NEW YORK, N.Y. BRONX, N. Y. BOSTON, MASS. 100 6th Avenue 542 E. Fordham Rd. 110 Federal Street CO NEWARK, N. J. PARAMUS, N. J. PLAINFIELD, N. J. RAD I 24 Central Avenue 182 Route 17 139 W. 2nd Street 16508 LIBERTY AVENUE JAMAICA 33, NEW YORK (1 Mi. North Garden State Plaza)

132 RADIO -ELECTRONICS

www.americanradiohistory.com 1. ST HI -FI KITS h to A New World of tertainment

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Each kit ha: the fine professional - MONEY 13.1C[í lod ng tous. Styled to blend with QUAR.NTEE every lechr. Lafayette Kit, ore excbtire product, of LorMeene Electro.- ,. Each Llartte kdt mutt set or exceed it, ¡nob/ ,bud ',wit: ationr. o ,our You can't gat better units at these .rl./r, . , me-ey swung prices.

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36 -WATT STEREO AMPLIFIER ... 59.SO BASIC STEREO AMPLIFILi ...134.5)

All Lafayette

Lafayette Radio Dept. JK -6 Send me the FREE 324 -Page P.J. Box 190 Jamaica 31, N. Y. 1961 Catalog No. 610 CUT OUT

AND PASTE

N. me ON POST

I Aswrets CARD

1 cer Zeno_ . state

NOVEMBER, 1960 133

www.americanradiohistory.com (Continued front. page 130) ATLAS "Job Rated" P. A. SPEAKERS Among other topics are antennas, noise, power supplies and test equip- ment. This new edition also covers emergency and portable operation. USING AND UNDERSTANDING PROBES, by Rudolf F. Graf. Howard W. Sams & Co. Inc., 1720 E. 38 St., Indianapolis 6. Ind. 51/2 x 81/2 in. 192 pp. $3.95. HU-15N NU-24N CJ-30N Where and how to use probes to test all types of electronic equipment accu- There is an Atlas Speaker Ideally Suited for EveryJob rately is the subject of this text. Writ- All Atlas P. A. speakers are highly efficient, especially in the voice frequency ten for the service technician and range, providing the extra "punch" needed to override high level background engineer, the book describes the many noise. Most are 100% weatherproof; aluminum and diecast parts are treated probes with corrosion inhibitors, then finished in "stone hard" baked enamel. The used in radio and TV servicing CJ Cobra -Jector horns are constructed of nonresonant, indestructible fiber plus special -purpose probes used in glas, and HU and TP speaker horns of aluminum, finished in gun -metal grey. industry, agriculture and medicine. The HU and TP speakers are particularly designed for efficient talkback -LS operations. The peaked characteristics within the voice frequencies increase the sensitivity of these speakers as pickup devices. ELECTROMAGNETIC FIELDS, ENERGY, All HU and CJ speakers are equipped with versatile "Versalock" ... This and FORCES, by Robert M. Fano, Lan Jen rugged, reliable mounting bracket, completely adjustable both horizontally Chu, Richard B. Adler. John Wiley & Sons, and vertically, provides positive locking in any position. Inc., 440 Park Ave. South, New York 16, The DU -12 and DC -5, Atlas' renowned DeCor projectors, are styled to hat*. N. Y. 6 x 9 in. 520 pp. $12.00. monize with any decor, modern or traditional. Send for free catalog to Dept, Most of this book is suitable for Model HU -12N HU-15N HU -24N CJ -14N I C1-30N Cí-44 TP -15N TP -24N DU -12 DC -5 junior and senior college students, the POWER 7.5 w 25 w 25 w 7.5 w 25 w 60 w 25 w 25 w 7.5 w 6w last 2 chapters being at graduate IMPEDANCE** level. 8 ohm 8 ohm 8 ohm 8 ohm 8 ohm 16 ohms 8 ohm 8 ohm 8 ohm 8 ohm FREQUENCY 350- 250- Readers should know physics, math 200- 400- 250- 150- 250- 200- 400- 120 - C.P.S. 10,000 10,000 10,000 10,000 10,000 9000 10,000 10,000 10,000 7000 and circuit theory. Vectors are intro- LENGTH OVERALL 744 in. 83/4 in. 12 in. 8 in. 144 in. 23" x 13" 164 in. 23 In. 14 in. 14 In. duced in the second chapter. Beginning BELL DIAMETER 74 In. 93/4 in. 1144 in. 91/2" x 51/2" 14" x 6" 19 in. 93/4 In. 1144 In. 7 in. 7 in. with Maxwell's equations in integral NET PRICE $16.20 $20.10 $22.35 $18.00 $24.60 $43.50 $31.20 $34.50 $19.80 $13.20 'Inpu form, the authors discuss circuit and field theory. All chapters close with ATLAS problems and references. SOUND CORP. TV SERVICING SHORT CUTS, by Milton 1449 39th Street S. Kiver. Howard W. Sams & Co. Inc., Brooklyn 18, N. Y. 1720 E. 38 St., Indianapolis 6, Ind. 51/2 x In Canada: 81/2 in. 104 pp. $1.50. Atlas Radio Corp., Ltd., TP-15N TP-24N History repeats itself. In TV repair Toronto, Ontario work, certain defects are more likely to recur than others. A group of 69 PROFESSIONAL ET,ECTRONIC PROJECTS - Organs, case histories are described here in OPPORTUNITY Timers, Computers, etc. -$1 each. List Free. PARKS, Box ADLETS 1005, Lake City Station, Seattle 55, Rash, detail. The symptoms, Rates -50c per word (including name. address and trouble location initials). Minimum ad 10 words. Cash must accom- and repair are given, together with pany all ads except those placed by accredited LEARN ('ODE.. Qualify for Amateur or Commercial agen- License. Free Book. cies. Discount, I0;ó for 12 consecutive issues. Mis- CANDLIHt SYSTEM, Dept, RE -11, some theory so the reader will be in leading or objectionable ads not accepted. Copy for Ifox 9220, Denver 20, Colo. Jan. issue must reach us before November 10, 1960. position to know what happened. Thus RADIOELECTRONICS, DISCOUNTS UP TO 50% on Hi -Fi amplifiers, timers, he is speakers, able to cope with similar troubles 154 West 14 St., New York 11, N. Y. tape recorders, individual quotations only, no catalogs. CLASSIFIED HI -FI EXCHANGE, 2375 East in the future. Schema ir' illustrate the 65th Street, Brooklyn 34. N.Y. procedures. -IQ QUALITY l'RINTINI L Economically priced. Speed_ service. Free samples on request. JOHN H. TAYLOR COMPONENTS. Recorders, Tapes. FREE Wholesale Cata- TOPICS IN ELECTROMAGNETIC THEORY, R. D. 2, Box 215, \Vest Middlesex, l'a. logue. CARSTON, 215 -T East 88th St., New York 28, N.Y. by Dean A. Watkins. John Wiley & Sons, LEARN THE MORSE CODE IN MINOJTES BY A Inc., 440 Park Ave. S., New York 16. N. Y. NEW CONCEPT OF LE.ARNINO SELF -II Y1 iNOSISI Pilo V I;N METHOD. Copyright senil Now on tape er 1900, Q2.00 to: 6 x 9'sá in. 118 record! Free Literature. AIrKINl,l \- EASY METHOD MORSE SYSTEM, Box 80, l'erry.burg. pp. $6.50. S \í1T11 ('0., Dept. 31138, T5, Box Saut Bernardino, Calif. Ohio. This is based on a lecture course CASH PAID! Sell your surplus electronic tubes. Want DON'T BUY HI -FI COMPONENTS, Kits, Tape, Tape organized for graduate students. The unused, clean radio and TV receiving. transmitting, spe- Recorders until you get our low, low return mail quotes. topics are related to cial- purpose, Magnetrons, , broadcast types, etc. "We Guarantee Not To Ile. Undersold." Wholesale Cata- microwave engi- Want military & commercial lab/test and communica- log Free. Ill- FIDELITY CENTER, 1797RC First Avenue, neering. They include periodic trans- tions equipment such as G.R., H.P., AN /UPM prefix. New York 28, N.Y. Also want commercial receivers and transmitters. For a mission systems, the helix, coupled - fair deal write BARRY, 512 Broadway, New York 12, AMPEX, Concertone, Crown, Magnecord, Presto, Norelco, N. Y. WAlker 5 -7000. mode theory and anisotropie media. Rogen, Tandherg, Sherwood, Rek- O -Kut, Scott. Shure, Dynakit, others.. , Trades. BOYNTON STUDIO, Dept. Much of this material has never before RADIO & TELEVISION RECEIVING TUBES. brand RE, 10 I'etutsylvania Ave.. Tuckahoe, N.Y. appeared in book form. new, first line name hi ands only. No rejects, no pulls. END Discounts up to (10% off list. EDISON TUBE CO.. ALL MAKES OF ELECTRICAL INSTRUMENTS AND Menlo lark, N.J. TESTING equipment repaired. HAZELTON INST1IIJ- MENT CO., 128 Liberty Street, New York, N.Y. Answers to "Sawtooth DIGNIFIED- 1:AIllo9SEl1 1:(SINESS CARDS -$:L95 Sticklers," page 90 per 1000. EDWARD PRINTING SERVICE, 74 :t0 Schrick Hl -FI DOCTOR will solve your hi -II problems on the ANSWERS: I -F, 2 -F, 3 -A 4-J, 5-H, 6-D, 7 -D, Drive, Parma 29, Ohio. 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NOVEMBER, 1960 135

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