WORLD'S LARGEST ELECTRONIC TRADE CIRCULATION

Tips on Color Servicir Color TV Horizontal Problems How to Choose and Use Controls Troubleshooting Transistor Circuits

MAY 1965 ENirr

The quality goes in before the name goes on

FOR THE FINEST COLOR AND UHF RECEPTION INSTALL ZENITH QUALITY ANTENNAS

... to assure finer performance in difficult reception areas! More color TV sets and new UHF stations mean new antenna installation jobs for you. Proper installation with antennas of Zenith quality is most important because of the sensi tivity of color and JHF signals.

ZENITH ALL -CHANNEL VHF/UHF/FM AND FM -STEREO LOG -PERIODIC ANTENNAS The unusually broad bandwidth of the new Zenith VHF/UHF/FM and FM -Stereo log -periodic resonant V -dipole arrays pulls in all frequencies from 50 to 900 mc-television channels 2 to 83 /\' plus FM radio. The multi -mode operation pro- vides nigh gain and good rejection of ghosts.

These frequency independent antennas, devel- , oped // by the research laboratories at the University of Illinois, are designed according to a geometrically derived logarithmic -periodic formula used in satellite telemetry.

ZENITH QUALITY HEAVY-DUTY ZENITH QUALITY ANTENNA ROTORS WIRE AND CABLE

Zenith quality antenna rotors are Zenith features a full line of quality heavy-duty throughout-with rugged packaged wire and cable. Also espe- motor and die-cast aluminum hous- cially designed UHF transmission ing. Turns a 150-Ib. antenna 360 de- wires, sold only by Zenith. Zenith grees in 45 seconds. The weather- wire and cable is engineered for proof bell casting protects the unit greater reception and longer life, from the elements. Each ro -tor and is available in various lengths to mounts easily to either a mast or suit every serviceman's needs. lower without an adapter.

Check the Yellow Pages for the Zenith Distributor nearest you. Or write to Zenith Sales Corporation, Parts and Accessories Division, 5801 West Dickens Avenue, Chicago, Illinois 60639, for Distributor name plus complete catalogue and technical information on Zenith Quality antenna installations. Specifications subject to change without notice. ... for more details circle 64 on postcard RCA Solid Copper Circuits

replace olcl»fashioned

"hand wiring.give 1V space age

dependability.

RCA Solid Copper Circuits are made by meth- ods as modern as tomorrow. They give greater dependability ... better TV performance. It's typical of the advanced design you'll find The Most Trusted Name throughout every RCA Victor home instrument. in Electronics T.k(s)' It all adds up to sets that are easier to service with results. so that owners are more satisfied BRAND I NAMES

makes More TV servicemen own RCA Victor Color TV than all other leading combined "NIS MRSSES'S VOICE"

MAY 1965 19 CTM 3410 good reasons

020 MFD 350 WVDC A10 MFD 350 WVDC that spell QUALITY -20MID 25 WVDC

dt0 ELECTRONICS, D

MADE IN U S A and SERVICE...

ARCOLYTIC superior quality electrolytic capacitors are made of 99.99% pure aluminum foil ...designed to operate at 85°C, and withstand I-igh ripple and surge voltages. All are made and tested to EIA RS -154. Premium grade materials and construction make 1 Arcolytics last longer...on the shelf...and in the set! Over 1400 values to meet all requirements for tubular and twist -mount elec- trolytics - single, dual, triple or quadruple capacitance in voltage combinations for radio, tv and industrial electronics. All unconditionally guaranteed! No extra charge for this high quality.

A Z. .01-10% 3. IKV ARCO general purpose Type ELMENCO Dip- ELMENCO High CCD ceramic ped Mylar-Paper Voltage Dipped disc capacitors (DP) capacitors Silvered Micas have improved give missile are solidly im- ceramic bodies quality at com- pregnated with which assure mercial cost. corona resistant longer life and Over 100 million material. They greater stability. are now in use. operate to 125°C The standard Whether for compared with CCD line has a radio -TV repairs 85°C for older -±- 10% toler- or critical indus- molded silvered ance and 1000 VDCW rating. It makes trial circuitry, reliable, dependable, types. Greatly re- possible a single ceramic disc stock for rugged Elmenco capacitors eliminate duced size and radial leads make them universal use. The "space -saving" size profit -killing call-backs and customer ideal for printed circuit use. Extra reli- of Arco discs is another feature de- complaints. Elmenco DP capacitors op- ability is assured through maximum signed to offer greater service conven- erate at 125°C without derating, are moisture resistance. Capacitance, toler- ience with complete safety of operation. completely moisture proof, and are up ance and working voltage are stamped Higher voltage ratings are available to 50% smaller than comparable types. on every unit. upon request.

You can get your Arco and Elmenco capacitors in any quantity within 24 hours from coast to coast. They're ARCO stocked in depth at Arco's reserve ware- houses (New York -Dallas -Los Angeles) electronics inc. serving authorized Arco distributors A LORAL SUBSIDIARY throughout the nation. Call your Arco COMMUNITY DRIVE, GREAT NECK, N.Y. 11022 distributor today! 516-487-0500

... for more details circle 13 on postcard 20 ELECTRONIC TECHNICIAN ELECTRONIC MAY 1965 VOL. 81 NO. 5 TECI".lrlew. WORLD'S LARGEST ELECTRONIC TRADE CIRCULATION

1141111C.9111111111116

RON KIPP Publisher See page 97 for details on our cover this month. JACK HOBBS Managing Editor QUINTO BOCCHI Technical Editor DOUGLAS HEDIN Industrial Editor JOHN BAILEY Assistant Editor THOMAS MURN Assistant Editor Basic Color Principles 45 MARY CONNORS Production Manager K. L. Rivers tells how to know your color TV fundamentals MAGGIE KANE Advertising Production 49 JIM GHERNA Art Director You and Color TV Don Borden continues his series covering color circuits RUTH GELINEAU Circulation Fulfillment Tips on Color Servicing 52 The old pro, L. C. Powell, says 'experience is still the best teacher' AN OJIBWAY PUBLICATION Spray it ... Renew It! 54 A round -up of aerosol -type service aids

Transistor Circuit Fundamentals 55 OJIBWAY PRESS, Inc. William Ganglinger Jr. tells how to make your transistor troubleshooting Ojibway Building, Duluth, Minn. 55802 and repairs easier

AREA CODE 218 727-8511 Service Seminars For 2 -way Radio 58 Space Age advances force technicians into continuing educational programs ADMINISTRATION: MARSHALL REINIG President Color TV Horizontal Problems 59 ROBERT EDGELL Executive Vice President Jay Shane tells you how to get acquainted with the new clues that DEAN MYHRAN Vice President point the way to various trouble areas GREGORY BLODGETT Treasurer BEN MARSH Editorial Director HARRY RAMALEY Production Director Choosing and Using Controls 62 JOE WOLKING Circulation Director Norman Nelson tells how to save time, money and aspirin when replacing controls, shafts and accessories Sales Offices:

NEW YORK: Ron Kipp, 25 W. 45 St. New York, N.Y. 10036 M b.% P'1111%ár1.I AREA CODE 212 581-4200 Letters to the Editor 22 Tough Dogs 70 26 New Products 72 CHICAGO: Jack Daniels, 221 N. LaSalle Editor's Memo 82 St., Chicago, III. 60601 Technical Digest 32 New Literature AREA CODE 312 CE 6-1600 Sync on Business 40 News of the Industry 92 Colorfax 66 Advertisers Index 100 LOS ANGELES: Anthony Merlitti, 1655 Beverly Blvd., Los Angeles, Calif. 90026 AREA CODE 213 MA 8-8556

`iED C

ABP r. ABC= YLP MOTOROLA: Color TV Chassis TS -908C-02 thru D-02 Copyright 1965 by Ojibway Press, Inc., Duluth, Minn. 55802. Reproduction and re- printing prohibited except by written author- ization of the publication. Subscription price: SYLVANIA: Color TV Chassis DO1.1, -2 $5 for 1 year, $8 for 2 years, $10 for 3 years. Foreign, $9 for 1 year, $14 for 2 years, and $18 for 3 years. If you have a change of address or a ques- tion about your subscription, write: ELEC. ZENITH: Color TV Chassis 25MC36 TRONIC TECHNICIAN, Circulation Department, Ojibway Building, Duluth, Minnesota 55802. BE SURE TO SEND ALONG THE ADDRESS LABEL FROM YOUR MOST RECENT ISSUE.

MAY 1965 21 LETTERS it TO THE EDITOR

Slight Misunderstanding Enclosed check to renew my sub- scription to ELECTRONIC TECHNICIAN. New RCA WR -64B I am very sorry about the misunder- Color Bar / Dot / standing and I thank you for your nice letter with explanation. . . . Crosshatch Generator Your policy . . . has no parallel that I know of in the technical pub- lishing business. This makes me proud to do business with a very fine organi- zation. Even if I had to pay double for my subscription it would be worth the money as your magazine has COLOR 6Gc+/GOC helped me more than a score of times. GEnEr.RTCP BILLY ALEXANDER Houston, Texas

Something Wrong? Isn't there La[ati .7d.La[ox something wrong with the captions at the top of page 46 in the February issue of ELECTRONIC TECHNICIAN? f"ATTERñ Jea FUNCTION JOHN HASKELL New York, N. Y.

There sure is. The references are wrong on Fig. 4 and Fig. 5. The an- tenna to the right is a cylindrical para- bolic. The one shown below the cap- tions is a log -periodic type antenna. -Ed.

From Out of the Brush I'm doing experimental work so far in the brush I almost have to carry a THE ESSENTIAL COLOR -TV ball of red string to find my way back to the nearest town. Have no contact with the outside TEST INSTRUMENT world (only Spanish spoken in this village) except Amateur Radio. Need- less to say there's a need to know. I Now in a new model with more features for greater stability and versatility am a new member of a group that Crystal -controlled RF oscillator for Generates all necessary test patterns: must be large indeed, the people that stable picture carrier. COLOR BARS for checking and aligning look to ELECTRONIC TECHNICIAN for color circuits; CROSSHATCH for Three additional crystal oscillators adjust- the answer You have it and there's ing vertical and horizontal linearity ... are used to produce the sound carrier, and no finer publication Just color sub -carrier signal and the three raster size; and DOTS for accurate con- ... thought patterns. vergence. I'd say thanks . . . From format to Convenient front -panel gun killing Color -phasing adjustments may be subjects covered, selected ads and switches to aid individual gun testing as made with this instrument in the home highly readable editing of articles, well as convergence and purity adjust- without a scope. you're just right for a large number ments. The standard of the Color -TV servicing of readers like myself looking forward Sound -carrier signal unmodulated for industry: much of the practical informa- to next month .. . accurate adjustment of fine tuning con- tion available for trouble -shooting color HUGH CABOT trol of TV receiver... accurate setting of circuits is based on the RCA Color Bar Villalobos Monitor Station the fine-tuning control is essential for Generator. WASKSQ - WASKSP - NXME checking the performance of the receiver. Only $189.50* Shafter, Texas ASK TO SEE IT AT YOUR AUTHORIZED RCA TEST EQUIPMENT DISTRIBUTOR "Optional distributor resale price. All prices subject to change without notice. Prices may be slightly higher in Alaska, Hawaii and the West. Liked March Issue Your March was a RCA Electronic Components and Devices, Harrison, N. J. edition hum- dinger! The best you have had in one edition in some time. Robert Mueller's The Most Trusted Name in Electronics piece on "Comes the Revolution" e should be removed from ET and

22 ELECTRONIC TECHNICIAN QUESTION When it comes to electrolytic capacitors, why do more than half of the nation's Radio-TV Service Technicians prefer to do business with Sprague Distributors?

NSWER: Because they don't want makeshift substitutions or multi -rating "fits -all" capacitors. They insist on exact A are always available through replacements, which Sprague Distributors everywhere.

SPRAGUE TWIST -LOK CAPACITORS... 1863 different ratings and sizes... the world's most complete selection of EXACT replacements!

We don't have to tell you that it's easier to service with exact replacements. And we don't have to tell you that it's better, too. When sets are designed, specific capacitance values are used for peak operation, so it takes exact replacements to restore original set performance.

And who better than Sprague knows which values and sizes are Wouldn't you really rather have what the replacement market? Sprague, the world's largest set manufacturer recommends? An exact needed in the file replacement in capacitance, voltage, and component manufacturer, has the most complete specification size is easier to install and less expensive, on original set requirements. That's why you're always right in most cases, than substitutes! when you service with Sprague TWIST -LOK exact replacements!

GET YOUR COPY of Sprague's comprehensive Electrolytic Capacitor Replacement Manual K-107 from your Sprague Distributor, or write Sprague Products Company, 65 Marshall Street, North Adams, Massachusetts. SPRAGUE® THE MARK OF RELIABILITY WORLD'S LARGEST MANUFACTURER OF CAPACITORS 6,1,63 R2

. for more details circle 60 on postcard 23 MAY 1965 "What our business LETTERS 4 TO THE EDITOR needs is a good UHF framed by most technicians. Many "technicians" don't know how a tran- VHF amplifier? "What sistor or "diode" works, and they have shied away from learning ... It won't be many years before everything com- our business needs is ing in for repairs will be sans tubes Another fine item in this edition was Robert Coy's "Selecting Replace- a good UHF -VHF amp ment Yokes." This article should also be dismantled from the magazine and studied by TV technicians. The article uf ier? "What our bu.:: "You and Color TV" should also be an introduction to the average tech- nician to `git busy' and learn some- thing about color systems ... Suggest you consider reprinting all of the schematics you have done in the past. I am sure that the newcomers to the field would appreciate the move .. . HORACE D. WESTBROOKS Griffin, Ga.

Thanks. We're thinking about re- printing a lot of TEKFAX schematics into bound volumes and making then available to the entire field. Ed.

Wants 2 -Way Articles Have subscribed to ELECTRONIC TECHNICIAN for some time and think "Say no more." you do a fine job of keeping service technicians up to date. I have been in TV -radio servicing for over 13 years. Received my commercial radio tele- phone license and now do two-way work . . . Would like to see at least "You mean there's an amplifier that covers all one article on two-way radio each TV channels from 2 to 83?" month .. . "You bet. In fact there are two-the outdoor U/Vamp-2 LAWRENCE J. ROSE and the indoor V/U-ALL2." Wellfleet, Mass. "Suppose I live in an area where there's only VHF?" "Your motto should be 'Be Prepared' because there Wants TEKFAX Items are a lot of new UHF I have all TEKFAX from July 1963 stations soon to come on the air. to date. Am looking to buy some These all -channel amplifiers are obsolescence -proof." printed before that date. Let me know "Anything I should know about the U/Vamp-2?" via ELECTRONIC TECHNICIAN. "Well, the U/Vamp-2 is compact and easy to install FRANK CARINGTON on the antenna mast. Has a remote AC power supply " Commerce City, Colo. "How about performance?" "Two transistors give you all the power you need Have TEKFAX - Will Sell for better reception on VHF and UHF. Also protect Have old ETs from July 1961 to against overload. Lists for $49.95." March 1964 and Circuit Digests (TEKFAx) groups 95 through 139 will "Supposing I don't want to put an amplifier sell. Also volumes 101 and 103 of upon my antenna mast?" schematics. Please make offer via ET. "Then use the V/U-ALL2. Not as effective as the DAVE HUDDLESTON Fox Park, Wyoming U/Vamp-2, but you don't have to climb a ladder .. . and it delivers signals to two TV sets. Only $42.50 list." "Guess I'll rush down and get one of the new Like some other technicians, I'm Blonder -Tongue UHF/VHF amplifiers." getting up there and retiring. Have a full set of TEKFAX from No. 1 to 908 (This message was paid for out of the gross profits of will sell. All filed in a portable metal BLONDER -TONGUE, 9 Ailing St., Newark 2, N.J.) Bi filing case and indexed . . . Sell the ... for more details circle 20 on postcard 24 ELECTRONIC TECHNICIAN For window -size blow-ups of this message, send 100 to Sprague Products Co., 65 Marshall St., North Adams, Mass., to cover handling and mailing costs. 11111111111111111111111,111111 AM11.11111111.1111111e

ARE TV SERVICE DEALERS GYPS?

Every so often, some magazine or newspaper sounds ice in a year. Most of the complaints came from folks off about TV -radio service shops. who expected first-class reception in doubtful fringe who tried to operate their sets without suitable "Service technicians are a bunch of gyps," is the areas; who had bought sets "wholesale" at ridicu- general theme. "They'll clip you if you don't watch antennas; or cut-rate dealers who could offer out." lously low prices from little or no service. They might just as well write the same thing about it takes almost as long to become a good doctors, lawyers, storekeepers, auto mechanics-or Actually, as it does to train for any other anyone else. There are gyps in every line of business. service technician Beyond this, it calls for regular study to Actually the percentage in TV -radio is lower than profession. constant stream of new developments. in most. keep up with the Also, it requires a surprisingly big investment in test The average service technician is a hard-working, instruments, manuals, and other shop equipment. The straight-shooting individual. Rather than gyp customers, modern TV or radio receiver is by far the most intricate he is far more likely to spend more time on a job than piece of equipment the average person ever owns or he knows he will be paid for-simply as a matter of uses. personal pride in doing things right. Service technicians are not fly-by-night businessmen - We recently heard about someone's TV set going 99 out of 100 run their businesses properly. The other bad. A service technician called for it with his truck one per cent-the gyps-can usually be spotted a mile and returned it in good working condition within 48 away. Nine times out of ten, they are the shops that hours. His bill came to $10 for service plus $2.68 for feature "bargain" prices and ridiculously liberal service replacement parts. contracts. And their victims are generally set owners who to the game by "getting something for The set owner argued that this was too much-yet he expect beat nothing." would never dream of complaining to the medical spe- cialist who charged him $10 for a 15 -minute office Good television sets or good TV service are not visit; the lawyer whose bill for writing a simple will was things to be bought on a "bargain counter" basis. Set $75; or the garage man who laughingly admits that he owners who recognize this aren't likely to get gyped. charges $5 for "just raising the hood" of a car. Instead, they'll find that they get more real value In one of our very large cities, the Better Business for their television entertainment dollars than for any Bureau received fewer than 500 complaints about serv- other dollars they spend!

THIS MESSAGE WAS PREPARED BY SPRAGUE PRODUCTS COMPANY, DISTRIBUTORS' SUPPLY SUBSIDIARY OF SPRAGUE ELECTRIC COMPANY, NORTH ADAMS, MASSACHUSETTS, FOR . . . YOUR INDEPENDENT TV-RADIO SERVICE DEALER

65 123 + . . for more details circle 61 on postcard

MAY 1965 25 A major breakthrough in F'I1VG AND UHF VHF. FM «COLOi4 VE-LOG" For the best reception in the world

UVF Color Ve- Log Antennas... Engineered for the Future! Finco's new All -Band Color Ve -Log Antenna does the work Revolutionary new UHF Section of three-gives startlingly clear black and white pictures Heavy Aluminum reinforced insulator insert cup and beautiful color on both UHF and VHF television and heavy duty rivet Back-up bracket and square boom channels. Its superlative design also assures the finest in Finco's exclusive triple thick sleeved elements stereophonic and monophonic FM sound reproduction. Lock-tite no -tilt saddle bracket Comparison tests have proved the superiority of the All - Finco's exclusive double contact to drive line Band UVF Series-superiority backed by Finco's guarantee Continuous one-piece drive line and exclusive of supremacy and unquestioned warranty. air insulated polystyrene cross -over spacer

Write for beautiful color brochure Number 20-322 and Coupler -Splitter Specification sheet Number 17-2308G Antenna design !

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UVF-24Finco Model For Near Fringe and Deep Fringe Areas

15 UHF Elements Channels 14 thru 83

9 VHF Elements Channels 2 thru 13 FM Monaural and Stereophonic Exclusive Gold Corodizing List $59.95 Featuring Finco's

Finco Model UVF-10 Finco Model UVF 16 Finco Model UVF 18 Fringe Areas For Metropolitan Areas For Local and Suburban Areas For Suburban and Near List $18.50 List $30.50 List $42.50 Prices and specifications subject to change without notice The FINN EY Company 34 Interstate Street Bedford, Ohio Dept. 110 ... for more details circle 30 on postcard e-

247 WAYS TO MAKE MORE

From now on, color -TV work is going to bring in a bigger and out it, when you have to pull a set into the shop, it takes two bigger part of your income. And RCA has EVERYTHING to men. With it, it takes just one (you pull the chassis only- make color -TV service MORE PROFITABLE for you. leave the color tube and the cabinet). That means MONEY To save you money and manhours. ...extra money for you. To increase your efficiency so you can get more jobs out Take the RCA Color Parts Rack (large unit at left). The in the same time. rack is FREE when you buy the basic complement of 120 To eliminate those time -wasting extra phone calls and most -needed color service parts. Keeps your color parts trips to the distributor. neatly organized, all in one place. Simplifies restocking, Take the famous RCA Color -TV Test Jig (large unit at lets you know what you're short of. No more running cut of right). It cuts manhours in half on a color house call. With- a vital part just when you need it-which slows down job. MONEY IN COLOR -TV SERVICE

That means MONEY... extra money for you. Take the other color service parts arrayed in the photo RCA Parts and Accessories for color -TV Degaussing coils, transformers, chokes, and listed at right. service include: Color Test Jig-to test all RCA color -TV cables, replacement parts...each with yokes, connectors, chassis Color Parts Rack-sturdy, well -organized ,unit con- the a special function to save you time, to increase quality taining complement of 120 most -needed color -service parts and accuracy of your work, to help you cut down on call- Degaussing coils-to demagnetize picture tube and chassis backs. That means MONEY... extra money for you! Special-purpose extension cables-to extend kinescope socket, 245 specialized color service parts in all. The Rack and deflection yoke, convergence magnet and kinescope high -volt- the Jig make it 247. And all of them mean MONEY..extra age leads when chassis is removec from cabinet for servicing IF test money for you. Special alignment probes-video detector test blocks, blocks, sound detector test blocks, mixer grid matching pad, tuner IF input head High -voltage interlock plug-to by-pass RCA PARTS AND ACCESSORIES, DEPTFORD, N.J. high -voltage shorting switch PI us sockets, transformers, fixed and variable capacitors, reactors, resistors, diodes, switches, coils ... EVERYTHING to save you time and make The Most Trusted Name in Electronics more money for you in color -TV service. 1( TECHNICAL DIGEST

ADMIRAL that the signal when developed at Pin No. 8 will be a Color TV Chassis Gil - Color Demodulator - Circuit Description result of a change in the amount of current flow to the screen. This change in current will change the screen Demodulation of the chrominance information is ac- voltage and a varying signal will result. Current flows complished by one tube (6LE8) and its associated circuitry. from cathode to Pin No. 8 because of the positive volt- The output signals, namely, the R-Y, G -Y and B -Y are age on Pin No. 8. When the plates (Pin No. 1 and No. 6) applied directly to the respective control grid of the pic- are alternately attracting electrons from the cathode, less ture tube. The 6LE8 provides amplification of all three will go to the screen. This decrease in screen current signals. raises the screen voltage. During the period that Pin To better understand the operation of this multi -func- No. 6 stops attracting electrons and Pin No. 1 is not yet tion stage, let's first examine the 6LE8 tube. We must con - attracting them, the electrons will be attracted to the screen grid. This increase in screen current will lower the ECM GRID screen voltage. R515 05111 C52í CRT R521 8522 L503 l RScro 6A - An additional factor is also important in the repro- B 3 TRAP III C510 R523 PS duction of the G -Y signal. This is feedback from the s BLUE 6LE8 ß525 BACKGROUND B -Y and R-Y demodulator plates to the control grid (Pin DE2ODULATOR H- Flia4 C516 RED GRID No. 9). This feedback network is made up of R520, C5141 C5151 !R529 CRT Vv zì527 8528 R525, and C510. Matrixing takes place between the B -Y C508 3TRAP TRAP R531:4,- and R-Y which is the equivalent of -(G-Y) being applied B, R ED 8516 a BAgtGRDUND back to the grid. All of these things combined result in GREEN ECO TRANS L506 2D the 358 MC CSBT rD5 full G -Y signals redeveloping at Pin No. 8. Adjust- R534 53 able traps are provided in the 6LE8 plate circuits to re- L5076 £8544 R5351, WS/ 8713 *I. -3 - move the TINT 3.58 Mc component. CONTROL GREEN BACKGROUND sider the two plates as being two separate tubes, each having a separate suppressor grid. The control grid and GENERAL ELECTRIC cathode are common to both tubes as indicated by the TV Chassis TA - Sound IF, Ratio Detector and Audio Stages - drawing. The left-hand section of the tube is the B -Y de- Circuit Operation modulator while the right-hand section is the R -Y de- modulator. G -Y signal is developed at the screen grid First Sound IF Amplifier: Q12, an NPN silicon tran- (Pin No. 8). We, in effect, then have a third plate, this sistor, is the first sound 4.5 Mc IF amplifier. The signal plate of course being Pin No. 8. from the secondary of T108 is connected to the emitter - Chrominance and high frequency information from base junction which is forward biased by the voltage the bandpass amplifier is applied to the control grid obtained from the dividing action of R300 and R303. The (Pin No. 9). The 3.58 Mc reference signal is applied collector -base junction is reverse biased through the se- to the suppressor grids (Pin No. 7 and No. 2). The phase ries connection of R301 and the primary winding of T30O. shift network provides approximately 90 deg phase shift The amplified 4.5 Mc FM sound signal appears in the between the two reference signals. During color this 90 deg collector circuit of Q12 across the primary winding of phase difference in the signals at Pin No. 7 and Pin No. 2 T300. This same signal is inductively coupled to the sec- allows only one-half of the tube to conduct at a time. ondary winding of T300 which is connected across the This action results in the reproduction of the B -Y signal emitter base junction of Q13. The germanium diode Y- at Pin No. 6 and the R-Y signal at Pin No. 1. 301 limits the amount of 4.5 Mc signal that can be de- The G -Y signal which is developed at Pin No. 8 is veloped across the primary of T30O. It also tends to a result of several things. First of all, we must realize suppress any ac variations that might be present in the

r 3_OI AUDIO 7 ÑTJE t/V gh . TAKE-OFF T302 ¡300 Terl 86V N 5V ell 1 eF 'ííííJ97jjjj--T -tc3o7 012 2ÓÖ 013 221Ñ £ R321 T30 5,062 ^C 83065 T5 -`218 0W 015 016 ;1.10 00 51062 830 8 cáóó£ 3000 065 IST AUDIO! - =T301 i AUD10l-F 600 L__J R34Ó COO2rf $1061 5,06, &A5 N97 2N0 ¡31 1sAUDIO uDIO 94V 2.65V 105V OUTPUT RJ04 5,12rAj41310 8V IOK T303303 3300R322 , 2.550 v 0Ó2u1 TO \ 0Ó3, AUDIO 305 122)SiÓÖ 6V .940 R305t8 C315 3V TAKE-OFF C302.1 3]00¡ 02u1 I TESTY TEST _ /O V POINT 3V C31 4 POINT 2.1V 02 21 ISVl IIV C311 R319 8324 fl 470 4.9V II I02 6V 7n 4 !00.1 ¡302 R]O] C306 3 .02.1 330 560 .D2NT 1-723 2- R326 7,2 Ç á'1i 22ÓÓ } 00 4.74. 180 .0384

)r IN-1-12V 82230000 IC]OI _C304 -¡ 20.1 11 5V

Audio stages of General Electric TA chassis

32 ELECTRONIC TECHNICIAN SYLVANIA PICTURE TUBE

ELECTRIC PRODUCTS INC. SYLVANA ,,u te x.,o., SENECA FA:.tE_ NEW YORK wwx aw .,, w..., o.o uu..,....e. (ARUM TEUFhGe+E a ELECTRONICS 97

Now your Sylvania Distributor can put you in The Yellow Pages sell the depend- The Yellow Pages are the first place Here's a special program that mean; customers that you tubes, in- people look when they want to buy. more customers and extra profits able line of radio and TV 85® Studies show that 90% of all tele- for you. Our ads appear in your local cluding famous SILVER SCREEN phone subscribers consult their Yellow Pages, directing customers and color bright 85® picture tubes. has Yellow Pages when they want to find to you. Your Sylvania distributor can Your Sylvania distributor full an how you can share in a local source for products and serv- show you how your own listing may particulars ices. It's a fact: your potentiaf cus- be part of the Sylvania ad. this program designed especially tomers let their fingers do the The new Sylvania Trade Mark for you. Check with him today. Sylvania walking when a TV set needs pro- Heading will be seen-it's big, at- Electronic Tube Div., fessional servicing. tractive, and descriptive. It tells Electronic Components Group.

SYLVANOF SUBSIDIARY GENERALTELEPHONE & ELECTRONICS GT&E SPECIAL COMPONENTS DISPLAY DEVICES NEW CAPABILITIES IN: ELECTRONIC TUBES SEMICONDUCTORS MICROWAVE DEVICES

MAY 1965 33 ways to TECHNICAL DIGEST increase

your form of spikes or noise. The purpose of R302 is to stabilize the 4.5 Mc amplifier, thus preventing it from oscillating. C302 filters high-frequency ripple from the B -i- line which may be present because of Y301 conduc- income tion. C300 is the emitter bypass. RCA Institutes, Inc. offers these four compre- Second Sound IF Amplifier and Ratio Detector: Q13 hensive home study courses especially de- along with its associated circuitry serves as the second signed to help build your income immediately! sound IF amplifier. The emitter -base junction is forward biased by the voltage obtained from the dividing action of R304 and R305. The collector-base junction is reverse biased through the series connection of R309 and the pri- mary of T301. The primary of T301 is tuned to 4.5 Mc, the center frequency of the second FM signal. The ampli- fied 4.5 Mc FM sound signal is inductively coupled to the secondary winding of T301. The ratio detector, Y302 and Y303, is similar to and functions in the same way as the ratio detectors used in pre- C : vious receivers. Signal from the secondary of T301 is ap- COLOR TV Add plied to the two germanium diodes Y302, Y303. The Color TV Servic- TRANSISTORS You get the nec- ing to your skills with this up-to- essary background for semiconduc- detected audio signal is developed across C309 which the-minute home training course tor technology including character- also provides some de -emphasis of the high frequencies. and take advantage of the growing istics of tunnel diodes, rectifiers profit potential in this area! Train and other solid state devices.Tran- First and Second Audio Amplifiers: The audio signal under the direction of RCA ... ex- sistor trainer also available. developed across C309 is fed through the volume perts in Color TV. control R311 and coupling capacitor C311 to the base of Q14, the first audio amplifier. Base bias is developed from the voltage divider R316, R317. The emitter resistor R318 maintains a constant input impedance between the base and ground. If the emitter were grounded, differences in parameters of replacement transistors would change the base-to -ground input impedance. The collector of Q14 is directly coupled to the base of Q15, the second audio amplifier. This is possible since Q15 is connected in an emitter -follower configuration with a AUTOMATION ELECTRONICS MOBILE COMMUNICATIONS high input impedance at the base which matches the output Trains you for the many applica- Trains you to service and main- impedance of Q14. R319 is the common load resistor tions of automation electronics in tain 2 -way radio communications industry and government for Q14 collector and Q15 base. C314, like C309, de- including on land, sea, and air! Gives you Photoelectronics, Digital Computer the technical foundation for space emphasizes the high frequencies. R320 is the emitter re- Techniques, Synchros and Servo- communications! sistor. Since Q15 is an emitter -follower, it has a voltage mechanisms, Automatic Control Systems, and many more! gain of less than one. Q15 is a power amplifier sup- plying power to the audio output stage. Audio Output Stage: The audio output stage uses a Take advantage of RCA's Liberal Tuition Plan. You only pay for NPN silicon transistor, Q16, as a power amplifier. Its lessons you order; and have no long-term obligations. Licensed by emitter -base junction is forward biased through the volt- New York State Education Department. Approved for Veterans. age dividing action of R323, R322 and the bias poten- RCA INSTITUTES, INC. tiometer R321. A Service of Radio Corporation of America It is important that this stage operate as a class A 350 West Fourth Street, New York, N.Y. 10014 amplifier. It should be noticed that test point VII provides a convenient check point for emitter current. The volt- 44A6_.3. The Most Trusted Name in Electronics age drop across the 4.7e emitter resistor, R324, is mea- sured and current calculated. Without signal, the stage is adjusted for class A operation by rotating the bias po- e> SEND THIS COUPON NOW FOR COMPLETE FREE INFORMATION BB tentiometer until +0.3 v can be measured across the RCA INSTITUTES, INC. Home Study School, Dept. ET -55 resistor. The +0.3 volt across R324 indicates approxi- 350 West Fourth Street, N. Y., N. Y. 10014 mately 65 ma of emitter idling current. Without obligation, rush me free information on the following RCA Home Train- ing Course: COLOR TV TRANSISTORS_ MOBILE COMMUNICATIONS_ The P-P audio current through T302 and Q16 is AUTOMATION ELECTRONICS_ quite high. Therefore, the RC filter circuit consisting of Name Age R326 and C316 is used to prevent these peak audio Address currents from modulating the +12v supply. City R327 limits the power supplied to the accessory ear- State Zip phone which may be plugged into J300. CANADIANS-Take advantage of these same RCA courses at no additional cost. LS is a 21/4 No postage. No customs. No delay. Send coupon to: RCA Victor Company, Ltd., 300 x 4 in. loudspeaker with a voice coil 5581 Royalmount Ave., Montreal 9, Quebec. impedance of 82. It is mounted on the left chassis side III MI---- M li BB MI M- MI MI MI ti MI MI panel.

34 ELECTRONIC TECHNICIAN ... for more details circle 30 on postcard 4 Model 3110-G

A new kind of ghost -killing antenna. Tailored to the Color Age. With a Power Equalizer

Circuit that makes every other so-called metropolitan color antenna look pale by contrast.

Color is going over the top this year. ratio than 10 -element yagis cut to each Front -to -back ratios up to 30 to 1. More color sets than ever are being specific channel). Thus its ghost - sold. killing power in color is extraordinary. Protected by exclusive E.P.C. Ghosting-not gain-is the big prob- Obviously ghosts in black -and -white "Golden Overcoat." ler in metropolitan areas, of course. are a pushover. And ghosts are even more trouble in What makes us so cocksure? Thou- color than in black -and -white. sands of installations throughout the Channel Master's Coloray licks both country. Time after time, they've What other antenna dares offer reception problems handily. It's hon- proved the Coloray's ghost -killing abil- Why? Because it's the this unique guarantee! estly unique. ity. And in places where all other an- most powerful antenna ever designed tennas have failed. to knock out ghosts and interference Coloray key to "Color -in black -and -white and color. It has The Coloray puts the the t en a revolutionary Power Equalizer Circuit City" in your hands. Use it to open °n s (which provides higher front -to -back door to tremendous new sales. ó eGvaRaNÌEEpfiminote ominiReghosts other sotfsnotyPe size CHANNEL MASTER OR yOURMONEYBqCK-9ordlesor VHF/FM STEREO BROADBAND ,/ Pnce O L R AY* "Pat. Pending The proof is on the roof!

Model 3600 Crossfire 28 elements

CHANNEL MASTER Crossfire outperforms, outlasts, and outsells every other antenna in the history of TV.

In America's suburbs...fringes...far fringes...in COLOR, black -and -white, FM/stereo

People spend upward of $350 just so they has more driven elements working with greater Clean Gain, too! can enjoy color TV. efficiency than any other antenna ... it delivers the highest antenna gain of all time. On each So doesn't it stand to reason that they would high band and low band channel-and FM want the antenna that is capable of bringing Stereo. out the best in their color set?

Sure it does. That's why... from metropolitan No color "suckouts" or dips! Flat gain. Perfect areas on out...the most powerful broadband impedance match assures absolute minimum of antenna you can sell is the Channel Master variations on each channel. It Golden Crossfire. For both color and black -and - white. Outlasts all others! Super -rugged design and LOW BAND construction means extra durability. Exclusive Extremely high front - By actual count, there are more Crossfire in- ratios...up to E.P.C. "Golden Overcoat" protects against to -back 16:1 on each band. stallations in America than any other antenna. corrosion. The Crossfire, in fact, is the largest -selling an- tenna in the world. Why? For color and for black -and -white, cover your Proportional Energy Absorption! The Crossfire market with the Crossfire-and you color your alone employs this unique principle. Because it cash register green.

To fit every area need ...Channel Master makes a complete line of Grassfires (including one with a built-in booster). Plus a complete line of super -powered Booster -Couplers ...and Super -Torque Rotators (automatic and manual). HIGH BAND A MUST In -Band Repeater Expands FOR 2 -Way Radio Range COLOR TV!

Installation of a UHF in -band shared community re- peater system has greatly extended the reliable operat- ing range for ten Chicago area FM mobile communica- tions system users. The single antenna for the shared repeater system is located on a tower 334 ft above ground, an impor- tant factor in the extension of operating range and the reduction of the effect of tall buildings on reception reliability. The economics to each subscriber are con- siderable according to Norman A. Sholseth, sales man- ager for Hallicrafters, who manufactured the equip- ment. NEW JERROLD CO LO RAX IA 11 Reception System

The old familiar twinlead, that worked pretty well for black -and -white TV, is hopelessly inadequate for color reception. When your customers complain about changes in color, ghosting, and smearing of pictures, chances are the fault lies squarely with the twinlead connecting the set to the antenna. What's the answer? Jerrold announces the exciting Coloraxial TV Reception System-an absolute necessity for color, and also best for black -and - Repeater system designed by Hallicrafters white and FM stereo. With Coloraxial, you can quickly convert any outdoor antenna to shielded coax operation. Installs anywhere in minutes, with- Transurban out need for standoff insulators or the fear of run- The system, owned and operated by ning near metal objects. Electronics Corp., is completely automatic, according Your customers will welcome the predictable, to a firm spokesman. perfect reception that's assured with a Coloraxial Calls between an individual subscriber's base and system. And you'll welcome the simplicity and prof- mobile units are monitored by a tone coded call system. itability of a Coloraxial installation. Jerrold Color - axial Kits give you everything you need for a quick, All receivers for a particular user are equipped to re- perfect job: 50 or 75 feet of sweep -tested, shielded spond and "open up" when triggered by a specific RG-59/U cable with fittings already on; matching additional overriding frequency tone gathered by a transformers for both ends of the cable-even transmitter operated by the subscriber. Receivers for Coloraxial (75 -ohm) antennas and preamplifiers where the job calls for them. other subscribers are not triggered and thus remain Talk with your Jerrold distributor today about silent. Coloraxial, or send coupon for complete information. The in -band community repeater system, with tone

coded calling, in effect permits multiple usage of the Jerrold Electronics Corporation same frequencies while reducing the volume of non- Distributor Sales Division Ave., Philadelphia, Pa. 19132 interest traffic for individual users. The only stipulation 15th & Lehigh Send me complete information on the new mobile transmis- TV Reception System. as to usage is that before any base or JERROLD Jerrold Coloraxial sion is made, the sender is required to monitor the Name frequency to avoid interference with a transmission al- Company ready in progress. This is done by momentarily turning Address the automatic tone call switch over to the oFF City State Zip position. .. . for more details circle 38 on postcard 37 MAY 1965 New

Inventory System

The time consuming process of taking inventory has been substantially reduced by a new method employing one instead of two persons. The system employs the Norelco "Carry -Corder 150," a lightweight (3 lb), cordless tape recorder. According to Lee Rocke, president of the Newhope Corp., sales reps for Centralab, who developed the sys- tem, "inventory taking in our distributor warehouses is a vital part of our service. But it was a time consuming, two -man job - one man to count the stock and an- other to write it down. "Today, by using a portable tape recorder, the job Your best buy is this complete requires only one man. And he gets it done in less time than it took two men by the old method," he added. With the Norelco unit, the inventory taker merely COLOR BAR GENERATOR snaps a tape cartridge in the machine, flicks a switch and goes down the shelves calling out part numbers and with exclusive Seco stability quantities of stock. He can go as fast as he likes. 15 -second warmup for your convenience Day- Not only does this save actual man hours but it en- long performance without variation Simple sync ables the company to maintain its sales pace by not hav- control-just vertical and horizontal hold Work - ing to bring a man in from the field and away from his a -day ruggedness-crystal controlled in heavy metal case. normal selling responsibilities, says Rocke. In the past a salesman would be brought in for a full day to assist in taking inventory. Additionally, the new method provides greater ac- curacy. At the MODEL 980 end of the in- 5U ventory taking, $119 Net the cartridges are marked and sent back to the office. The in- MODEL 980 does everything you need to set up a color TV formation is set KEYED COLOR BARS for aligning and trouble shoot- ing color circuitry - 10 standard bars DOT PATTERN for then transposed DC or static convergence - 64 dots CROSSHATCH for dynamic convergence. Overscan and linearity adjustments - to an actual in- 6 horizontal bars. 9 vertical bars VERTICAL BARS for ventory sheet. adjusting dynamic horizontal convergence controls - 9 verti- cal bars HORIZONTAL BARS for adjusting dynamic The cartridge vertical convergence controls 6 horizontal bars. - system not only insures simplici- ty and speed of operation but it MODEL 990 also protects the $149 5U Net tapes from acci- dential unwind- ing or other damage. The MODEL 990 gives you all the deluxe features! ALL the tape cartridge tests of the Model 980 with these extra advantages- also is a positive COLOR GUN KILLER to actuate any combination of guns RAINBOW COLOR PATTERN to supplement keyed color record in case bar tests VARIABLE DOT PATTERN with 54 or 144 dots of adjustable size VARIABLE CROSSHATCH with 6 or 16 questions arise horizontal bars VARIABLE HORIZONTAL BARS with 6 or 18 lines GREY RASTER for tests required on older sets. about the inven- tory and, at the Write for full information. next inventory time the car- tridges can be SECO ELECTRONICS Norelco portable tape recorder being used to 1211 S. CLOVER DRIVE, MINNEAPOLIS, MINN. 55420 take inventory. reused. .. for more details circle 55 on postcard 38 ELECTRONIC TECHNICIAN Sell your customers TV masts, towers that last

Install TV masts and towers that last, and you'll have 000000DZ3333000000000000000EDED3 of a pleased customer when you Armco Steel Corporation, Steel Division the extra advantage Department E-2575, P. O. Box 600 want to sell other high -profit items in your line. Middletown, Ohio 45042 Masts and towers of Armco ZINCGRIP® Steel Tubing Send me names of manufacturers of TV masts and towers of are steel -strong and protected with a durable zinc coat- Armco ZINCGRIP Steel Tubing. ing to fight rust. They're not like flimsy masts that might NAME buckle before you have time to collect for installation. FIRM Get names of manufacturers who make masts and STREET towers with these features that help you sell. Fill in CITY STATE ZIP and mail the coupon now. 0CIDDDDDDDDEI0EDDDLIDDDOCIODUDDOEHMDD00E

ARMCO STEEL ARMCOv ... for more details circle 14 on postcard 39 MAY 1965 1( SYNC ON BUSINESS

A repeating sound motion picture projector can tell Tarzian, Inc. It comes with the purchase of a special your product story or sales message on a 10 in. screen in silicon rectifier package being offered at $9.95 net. Ac- full color or black and white. An all silicon transistor am- cording to the company, the rectifiers would cost $10.41 plifier gives undistorted sound from a whisper to audi- if purchased separately.

A four by five ft double-face vertical outdoor sign and a companion 15 x 50 in. single -face indoor sign, made phi ILC CI) COLOR TV

torium volume. The unit weighs only 17 pounds. Film can be repeated without removing the magazine. Pro- RIVALED vides up to 22 minutes of color and up to 40 minutes of ONLY BY NATURE B/W film. Made by Electronic Audio -Visual Devices. JONES APPLIANCE An average of 570 records were played by music lovers in the U.S. in 1964, according to Jensen Industries. The Beatles were the most played records, the survey indicated. A query also showed that 85 percent of the phonograph owners could not recall the approximate date that they especially for promoting color TV, are available from had changed their phono needle last. Philco. A panel on the outdoor sign bears the dealer's name. At your Philco distributor. Pleasure -boat two-way radio is high-lighted in NBC TV's `Flipper" series. It's by Pearce-Simpson. Photo Sound Reinforcement and the New Liturgy is an ex- cellent booklet for public address system promotion. Is-

SauHQ Reinforcement and the JUew,CIturgy f shows Brian Kelly, (left who plays part of Porter Ricks, chief ranger of the Coral Key Park on the Florida Keys) communicating with a shore station as Luke Halpin, "San- dy," looks on.

A free wrench kit, ideal for radio and TV service sued by Electro -Voice and available at your audio equip- work, is waiting at your distributor, according to Sarkes ment distributor.

40 ELECTRONIC TECHNICIAN EICO BRAND NEW FOR '65 NEW EASY -TO -BUILD EICO KITS / OVER 230 LABORATORY PRECISION KITS

COLOR TV LAB EICO 342 FM-MPX HOME COLOR TV SERVICING. THREE COMPACT, PORTABLE INSTRUMENTS FOR SHOP OR SIGNAL GENERATOR ADD ONE MORE AND YOU'RE SET FOR FM-MPX STEREO. FOR PROFITABLE SERVICING IN THE FAST-GROW- ING FM STEREO MARKET. PRO- VIDES BOTH A COMPOSITE AUDIO SIGNAL FOR DIRECT IN JECTION INTO MPX SECTION AND FM RF PLUS SYNC OUTPUT.

WIRED $149.95. EICO 380 COLOR EICO 369 SWEEP AND EICO 435 3 -INCH OSCILLOSCOPE GENERATOR POST -INJECTION MARKER GENERATOR ULTRA COMPACT! TAKE IT PORTABLE, SOLID STATE ALONG ON SERVICE CALLS. N.T.S.C. STANDARD COLOR FOR EASIEST, FASTEST BRIGHT. SHARP TRACE ON VISUAL ALIGNMENT OF FLAT -FACE 3 -INCH CRT EX- SIGNAL & DOT -BAR GENER- DIAM ATOR (PAT. PEND.). GENER- COLOR OR B & W TV AND PANDABLE SEVERAL FM RF AND IF CIRCUITS. ETERS. FLAT DC TO 4.5 MC/S. ATES 11 DIFFERENT GRID. COLOR SIGNALS, ONE AT A FIVE SWEEP RANGES FROM EDGE LIT CALIBRATION TIME. PROVIDES N.T.S.C. 3-220 MC/S. FOUR MARKER ZENER CALIBRATOR. OUT- EXACTLY AS RANGES FROM 2-225 MC/S. PERFORMS 5 -INCH SCOPES COLOR SIGNALS BIG E G U ESS- CRYSTAL MARKER OSCILLA- THREE TIMES AS AND SPEC I FI ED. TAK ES TH LAB WORK OUT OF COLOR TV TOR. POST INJECTION OF TWICE AS HEAVY. TRUE SERVICING. MARKERS. QUALITY. KIT ONLY $129.95. KIT ONLY 89.95. KIT ONLY $99.95 WIRED $169.95. WIRED $139.95. WIRED $149.95.

THESE FAMOUS BEST SELLERS FROM EICO'S SELECTION OF 230 KITS AND WIRED UNITS. EICO 460 5 -INCH EICO 232 VTVM EICO 667 TESTER EICO 324 RF SIGNAL GENERATOR OSCILLOSCOPE PEAK -TO -PEAK TUBES & A MUST FOR TRANSISTORS DC WIDEBAND COLOR OR 0-4.5 MC FOR B&WTVAND 4.a..'' COLOR & B & W INDUSTRIAL TV SERVICE & USE. 7 NON - LAB USE. PUSH- SKIP RANGES ®.9 , PULL DC VER- ON ALL 4 TICAL AMP. FUNCTIONS. U NBAL. TESTS RECEIVING, SPECIAL 150 KC/S TO 435 MC/S RANGE. BAL. OR WITH AND INPUT. AUTO- PURPOSE, NUVISTOR AND FOR IF -RF ALIGNMENT SYNC UNI -PROBE®. COMPACTRON TUBES FOR DY- SIGNAL TRACING OF TV, FM, MATIC TWO- AM, CB AND MOBILE. BUILT-IN LIMITER AND NAMIC CONDUCTANCE. AMP. KIT $29.95. STEP TRANSISTOR TEST. AND EXT. MODULATION. KIT WIRED $129.50. WIRED $49.95. KIT $79.95. WIRED $129.95. KIT $28.95. WIRED $39.95. $89.95.

EICO 1064 DC SENTINEL 23 CB TRANSCEIVER NEW EICO 3566 SOLID STATE FM-MPX POWER SUPPLY STEREO TUNER AMPLIFIER TESTINGFOR BENCH NEW AUTO RADIOS, (MODEL 779) CB, MOBILE IN THE HIGHEST AND TONE QUALITY RANK, WITH EQUIPMENT. WIRED $169.95. 43 TRANSISTORS, VOLTMETER 19 DIODES. 6 RECTI- AND AM- 23 CHANNEL FREQUENCY SYNTHESIZER PRO- FIERS. 112 WATTS METER. LOW VIDES CRYSTAL -CONTROLLED TRANSMIT AND INTO 4 OHMS 75 RIPPLE FOR RECEIVE ON ALL 23 CHANNELS - NO ADDI- WATTS INTO TO BUY EVER! FEATURES TRANSISTOR TIONAL CRYSTALS 8 OHMS. 38-40 DB CHANNEL SEPARATION. AUTO- EQUIPMENT. INCLUDE DUAL CONVERSION, ILLUMINATED INTERSTATION MUT- AND MATIC STEREO SWITCHING. 0-8V/ 0-16V "S/RF" METER, ADJUSTABLE SQUELCH ING. FRONT-END, IF AND MPX SECTIONS PRE -WIRED I AND OUTPUTS. NOISE LIMITER, TV FILTER, 117 -VAC AND PRE -ALIGNED. PLUG-IN TRANSISTORS. 12-VDC TRANSISTORIZED DUAL POWER SUP- WIRED WITH CAB. $349.95. KIT $45.95. WIRED $54.95. PLY. ALSO SERVES AS 3.5 -WATT P.A. SYSTEM. KIT ONLY $229.95.

F EICO Electronic Instrument Co., Inc. 1131-01 39th Ave., Flushing, New York 11352 LINE SEND MOST COMPLETE SEND 1965 CATALOG LISTING 230 EICO PRODUCTS. ET -5 OF KITS AND WIRED FOR TEST EQUIPMENT, CB NAME AND HI-FI COMPONENTS. FREE ADDRESS CATALOG CITY STATE ZIP

... for more details circle 28 on postcard 41 MAY 1965 ACE TV SERVICE 081100 INSIAI1 Al10NS _t` IONOUR JFD LPV 7 Don't Be Set... -v III0,0*. IW JFO LP With JFD LPV log

model list LPV-TV19 $69.95 LPV-TV16 59.95 LPV-TV13 49.95 LPV-TV1O 39.95 LPV-TV7 29.95 NEW! LPV LOG PERIODIC WITH C -ELECTRONIC LPV-TV5 21.95 DIPOLE FOR VHF CHANNELS TO 13 LPV-TV3

model LPV-VU 18 $ 69.9 LPV-VU15 59.9 THE 1FD LPV-VU WITH CAP ELECTRON C DIPOLES THAT LPV-VU12 49.9 RECEIVES ALL CHANNELS 2-83 AND FM STEREO USING LPV-VU9 39.9 ONE DOWN -LEAD! LPV-VU6 27.

model list LPV-U21 $27.95 LPV-U15 18.95 model list LPV-U9 12.50 LPV-ZU20 UHF LOG -PERIODIC FOR CH. TO 83 AND CH. 7 TO 13 $34.95 LPV-U5 6.95 UHF ZIG -A -LOG ANTENNA FOR CHANNELS 14 TO 83 LPV-ZU10 15.95

Only JFD offers You LPV Log Periodics for VHF (Ch.2-13)... UHF

GET THE LION'S SHARE OF ANTENNA BUSINESS (FLATTEN CATV COMPETITION, sonic Pavilion, Formica House, Eastman Kodak Exhibit, New York City TOO) BY FEATURING THE JFD LPV-VU LOG PERIODIC! THIS NEW GENERATION OF Exhibit, House of -Japan and other Fair showplaces chose the JFD LPV. This LOG PERIODIC ANTENNAS DELIVERS WHAT VIEWERS WANT-MANY MORE exclusive preference is pre-selling millions of Fairgoers-opening the door STATIONS...VHF CHANNELS 2 TO 13...UHF CHANNELS 14 TO 83...FM/STEREO. for more LPV sales by you. GIVES TFE CLEAN, UNIFORM SIGNAL SETS NEED ESPECIALLY FOR VIVID COLOR RECEPTION. Only the LPV follows the patented frequency independent Log Periodic WHY THE LOG PERIODIC IS THE MOST antenna formula developed by the Antenna Research Laboratories of DRAMATIC BREAK WITH ANTENNA the TRADITION SINCE DR. YAGI INVENTED THE YAGI Universi -y of Illinois. This new log periodic cellular concept provides you ... Up until the JFD Log Periodic, it was not possible to devise a with a combination of gain, bandwidth, directivity and impedance match truly broadband antenna except never by "compromise" design that had to give before possible with conventional up vital gain to get wider bandwidth antenna designs. ... or had to degrade directivity for better imped- You can actually see the difference in ance. Burdensome parasitics were piled on truer color purity, in greater contrast, in finer detail-not to try to compensate for gain "suck -outs", on just some of the chan- ghost -prone polar patterns, and nels but all of the channels! inadequate Small wonder bandwidth. This pyramided performance more JFD Log Periodics were installed in complications resulting the last 12 months in signal -sapping than any other brand. standing waves and impedance matches- PREFERRED BY MORE N. Y. WORLD'S FAIR and yet were only effective at the band edges. PAVILIONS ... New York World's Fair ex- Through the use of the revolutionary hibitors demand flawless color reception. new logarithmic periodic formula, the en- That's why the House of Good Taste, Ma - tire frequency range is covered with dipole Be A 1 1 Set- Periodic TV & FM Antennas

E FIRST LEG PERIODIC TRAPEZOID INDOOR ANTENNA - FOR CHANNELS 2 TO 83 ULTRA VU -VISTA VHF -UHF INDOOR AN1EN.IA

model list LPV-17 $59.95 LPV-14 49.95 THE FAMOUS LPV FEATURING ADVANCED LPV-11 39.95 NEW LOG -PERIODIC PARAMETERS! LPV-8 29.95 LPV-6 21.95 FOR VHF CHANNELS 2 TO 13 AND FM STEREO LPV-4 14.95

model list LPL-FM1O $49.95 LPL-FM8 39.95 model LPL-FM6 29.95 LOG PERIODIC FM STEREO ANTENNA LPL-FM4 19.95 LPT-100 (Ch. 14-83)...FM/Stereo...VHFIUHF/FM-,1.1 LO & Black/White

groups (cells) of overlapping resonances. These harmonically resonant ADVERTISED IN LOOK, SUNSET ... COMPARE ADVERTISING AND PROMO- V -dipoles result in a frequency -independent performance. The LPV's inhe- TION! ... A versatile selection of indoor and outdoor sales helps ... adver- rently high gain, sharp directivity, 300 ohm impedance match and flat tisements in LOOK, SUNSET and other national and local consumer publica- response are virtually constant across the entire band. tions ... in newspapers ... on television ... sell your best prospects. Now is the time and your JFD distributor is the place to stock up and IT! The JFD LPV is the product of the AND ONLY THE JFD LPV HAS ... step up into big -league LPV Log Periodic profits. world's largest and newest antenna laboratories. Here, in the JFD Cham paign, Illlinois R & D Research Center, a team of scientists and engineers, SEE WHY AT THE MOMENT OF TRUTH THE PICTURE IS THE PROOF THE under the direction of Dr. Paul E. Mayes, are revolutionizing the state of JFD LPV LOG PERIODIC WORKS BEST! the antenna art. Patents 2,958,081; 2,985,879; 3,011,168; 3,108 280; COMPARE CONSTRUCTION! .. Life -time Licensed under one or more of U.S. MECHANICALLY SUPERIOR! ... 3,150,376 and additional patents pending in W.S.A. and Canada. Produced by JFD stainless -steel take-off terminals that can never corrode, "tank -turret" ele- Electronics Corporation under exclusive license from the University of Illinois Foundation. ment brackets, tough heavy -wall Implex A acrylic insulators, twin U -bolts with 6 inch mast grip span; supple, permanently riveted aluminum drive . for more details circle 39 on postcard line rod; electrically conductive gold alodizing; plus a host of other exclusive mechanical improvements. JFD ELECTRONICS CORPORATION FIGHT CATV WITH THE JFD LPV! Keep CATV out of your area with JFD Log 15th Avenue at 62nd Street, Brooklyn, N. Y. 11219 Periodics (such as the 82 -channel LPV-VU) which provide viewers with more JFD Electronics -Southern Inc., Oxford, North Carolina color-plus FM stereo. Don't install in- JFD International, 64-14 Woodside Ave., Woodside 77, N. Y. channels-sharper reception-richer Ontario, Canada ferior antennas that open the door to CATV. Install the best to get the best JFD JD Canada, Ltd., 51 McCormack Street, Toronto, performance-the LPV! cor ri ht 1965, 1FD Electronics Co Next time you need one, get it fast. Mail this coupon. Cathode ray tubes, receiving tubes and genuine Philco parts - your Philco Parts Distributor has them. In one quick stop you can also get universal replacements for nearly every TV and radio ever made, a tremendous range of national brand components and many profit -making accessories and extras. The rare time a Philco part isn't in stock, Philco's Lifeline Emergency Service jumps into action. Your order is instantly transmitted to Philco's national parts depot in Bedford, Indiana - and the part you need is on its way to you, by air, in 24 hours or less. YES, Philco, I want faster, complete parts service! Tell the nearest Philco Parts Distributor to send me information about special Extra services from your Philco Parts Philco Parts offers, prices and facts. And tell him to hurry! Distributor include valuable knowhow and data on just about every TV, radio or phono ever Name made. When you're stuck on something, he's the Address man who can help you. If you're not getting this kind of fast, one -stop City Zone parts service, you should. Mail the coupon and State start doing business with your Philco Distributor. Mail to: Philco Parts & Service Department PARTS & SERVICE DEPARTMENT P. O. Box No. 3635 Philadelphia, Pennsylvania 19125 1 PH I LCO h as im BR la A SUBSIDIARY OF vcir ff or .0777A2f?f,

.. for more details circle 52 on postcard 44 ELECTRONIC TECHNICIAN ELECTRONIC TECHNICIAN

MAY 1965

Basic Color Principles

Know your color TV fundamentals and stay in the business

4 ZüLeit4

Those who fail to study and of these few so-called "pure" colors. learn all about color TV will event- That white light is made up of ually fall by the wayside and ulti- all these wavelengths, can be dem- mately face extinction in this busi- onstrated with a prism (Fig. 2). A ness. Color TV will probably white light beam passing through represent the major income poten- a prism goes from one transmitting tial for those who survive and who medium to another - causing the now concentrate on B/W TV. beam to bend. Each individual light To thoroughly understand color frequency has a different refraction TV, it is necessary to learn all index-causing each color to bend about basic color fundamentals of at a different angle. The lower fre- light and the capabilities of the human eye, for ex- quencies - red, for example - do not bend as ample. And these principles must be thoroughly di- much as the higher light frequencies - in the di- gested if you ever hope to furnish the kind of color rection of blue and violet. The color chart shown in TV service that TV owners will be demanding in the Fig. 2 is somewhat distorted so a clearer presentation future. can be made. The bandwidth of each color has been shown nearly equal but actually some colors have a Light Spectrum much narrower bandwidth than others. The process As we know, light waves exist in the electromag- shown here can be reversed - the human eye has netic radiation spectrum-the same as TV, radio and the facility to add all these wavelengths and "see" radar waves. But light exists at very high frequencies white light. and has extremely short wavelengths. Light waves are White light can also be obtained by using only measured in millimicrons. A millimicron is equivalent three colors - one from the high frequency end of the to one thousandths of a millionth of an inch. The wave- spectrum, one from the low end and one from the length of visible light, for instance, extends from about middle area. This principle is applied in color TV. 400 to 700 millimicrons. Infrared light frequencies lie Light Characteristics just below and ultraviolet light just above visible light frequencies in the electromagnetic radiation spectrum. A system has been established to define colors White light is composed of a continuous spectrum used in TV. It consists of three definite aspects of a of colors, with red having the longest and violet the color. Brightness is the total amount of light, regardless of the color and satura- shortest wavelength (Fig. 1) . The degree of sensitivity of color. Hue is the frequency of the human eye to various frequencies of visible light tion is defined as the degree of color purity. In color chrominance is shown within the curve. As illustrated, the colors TV, hue and saturation are part of the are pure, or spectral colors, and are seldom seen in signal and the brightness is sent as the luminance this way. Colors appearing in nature are combinations (B/W) signal.

45 MAY 1965 1.0

.B

6

.4

COLOR SPECTRUM OF WHITE LIGHT

.2

o 400 500 600 700

WAVELENGTH IN MILLIMICRONS

T Fig. 1-Frequency response curve of human eye across visible light spectrum. The eye is most sensitive to hues in the green -yellow area.

Fig. 2-A white light beam passing through a prism is divided into its component hues from deep red to deep violet.

Color Combinations It is known that a combination of two differ- ent colored light beams will produce another color and that this color will be different than either of the other two. The color formed will appear as a complete color to the eye and neither of the original colors will be visible. But two colors limit the number of colors that can be formed. Addition of a third color greatly in- creases the number of available colors. In color TV, the three primary colors are red, green and blue. Ex- perience has shown that combinations of red, green and blue offer the greatest selection of colors. When all three colors are mixed, the resultant is white and the combination of two individual colors produces ad- ditional colors (Fig. 3). Four or more primary colors could have been used with better color rendition but when we consider human -eye limitations it is found that three basic colors can produce a highly acceptable variety of colors. As shown 3, Fig. 3-When blue, green and yellow light are mixed in proper in Fig. a combination of green and proportions, white light is produced. Where the red and blue beams blue produces cyan. By combining red and green, we overlap, a magenta hue is produced. Red and green mixes to produce yellow and from a combination of red and produce yellow and blue and green produces a cyan hue. By varying the relative amounts of any two colors, various hues are produced. blue we obtain magenta. By varying the amounts of

46 ELECTRONIC TECHNICIAN individual colors, almost any color the eye can detect signal are transmitted within the 6 Mc passband al- can be produced. lotted to a TV channel. The Eye Chromaticity Diagram The human eye is a very complex organ but it has A chart devised to easily obtain color mixing in- some limitations which are taken advantage of in the formation is shown in Fig. 4. The wavelengths of the color TV system. Light rays enter the eye and the various spectral colors are indicated on the outer edge impressions created are transferred through the nervous of the curve. Any point not on this curve but located system to the brain, producing color sensations for within the diagram is not a pure color but a mixture the individual. The eye reacts differently to each light of spectral colors. Pure white, a mixture of all colors, frequency. is located near the center of the color triangle. This Some colors are more easily seen than others. The color triangle, located within the horse -shoe shaped response curve (Fig. 1) illustrates the reaction of the diagram, represents the range of colors we are able eye to the various colors of the spectrum. The greatest to reproduce in our color TV system by using the sensitivity is experienced in the green-yellow region. standard wavelengths of red, green and blue primaries. This fact was also taken into consideration when com- The wavelengths chosen as standard are 700 mµ for patible color standards were established. Unequal red, 520 mµ for green and 400 mµ for blue. Any color amounts of each primary color are used to make up value not included in the triangle cannot be reproduced the luminance (brightness) or "Y" portion of the color by any combination of the three primary colors chosen. TV signal. In fact, 59 percent green, 30 percent red The chromaticity chart is plotted in values along an and 11 percent blue are mixed to obtain a monochrome X and Y axis. Any color can be identified in terms (B/W) picture. of an X and Y value. For example, 0.5X plus 0.3Y When viewing a color picture, the eye is unable would represent a shade of red. Any given color could to resolve fine color details. The larger the color area be reproduced exactly by transmitting these X and Y is in a picture, the easier it is for the eye to identify values to another location. the colors. For these reasons only the larger areas of Take the color triangle and cut a circle from the color information need be transmitted in our color TV center and draw two interesecting axes with pure white system. The fine detail portion of the picture is in- at the point of intersection (Fig. 5) . Label the axes cluded in the brightness part of the signal. The hue B -Y and R -Y instead of X and Y. Now any color can and saturation of only the larger areas are transmitted be identified in terms of B -Y and R-Y. In actual color as a separate signal. Because of eye limitations, the TV practice, the phase angle represents the hue of a color portion of the signal may have a narrow band- scene and the amplitude of the resultant represents width. This portion of the signal is used to modulate saturation. a color subcarrier and both this and the brightness ELECTRONIC TECHNICIAN will go deeper into this subject in forthcoming issues. R -Y

Y 520

8-

B Y

.4

.3

R Y

Fig. 5-Rotating vector diagram showing relationships of the three basic colors to R -Y and B -Y axes and phase angle relationships of the three basic colors from burst reference.

Fig. 4-Approximate range of printing inks compared to NTSC range .. of all hues and saturations with respect to white. Triangle indicates X 7 color TV chromaticity range.

47 MAY 1965 You and Color

B -Y B-Y TO BLUE DE MOD AMP: GRID

The chrominance (chroma, or color) circuits of a color TV re- FROM BANDPASS PHASE G -Y VAMPIDEO TO ceiver are designed to process color AMP SHIFT AMP GREEN information telecast by TV stations. GRID Some changes have occurred in these circuits over the years, but basic functions 3.58MC R -Y R -Y remain the same: -.TO RED OSC DEM OD AMP the circuits amplify, detect and mix GRID in correct proportions the color sig- nals sent out by the transmitting Fig. 1-Block diagram of chroma circuits of a typicaï station. The diagnose, isolate and repair approach of every skilled technician -mentioned in the introductory quency, but displaced 90 deg out article of this series-(ELECTRONIC of phase, are produced. The two TECHNICIAN, page 60, March, components are then combined into 1965) also holds true for chroma a single component which varies circuitry. And the proper applica- both in amplitude and phase. This tion of a color-bar/dot generator, system suppresses the 3.58 Mc sub scope and VTVM, should solve any carrier and transmits the chroma in- service problem encountered in this formation as upper and lower side - area. bands. This will be discussed later To effectively troubleshoot in greater detail. chroma circuits, however, you'll The primary purpose of our color need to understand the basic operat- TV chroma circuitry, in a few ing principles of each section and words, is to "decode" and separate the part each plays in the over-all color information from the com- color reproduction job. As shown in posite video information - to re- the simplified block diagram (Fig.1) produce a replica -scene on our color the chroma portion of a typical color receiver's CRT - precisely like TV receiver is composed of eight that televised in the transmitting major circuits. The color burst, station studio. But let's take a closer killer, etc., circuits are not shown Fig. 2 (A)-IF response curve of a typical color look at some of the circuitry in- receiver. (B)-Response curve of a color TV here. volved in this process. bandpass amplifier. (C)-Over-all chroma Before we proceed, however, to response of a color TV set. the essential functions of each block Bandpass Amplifier let's briefly recall, in a very sim- Our color "decoding" process be- plified way at this point, that color gins by taking a composite video quency of 3.58 Mc and is usually information is interleaved between signal from the video detector or designed to pass a band of chroma regular black -and -white informa- first video amplifier output and ap- signals approximately 1.2 Mc wide. tion. This is done in a special way, plying it to a special bandpass am- This circuit has a tilted response primarily by employing a carefully plifier. The bandpass stage (or with the curve dropping off at the established 3.579545 Mc (3.58) stages) amplifies the chroma infor- lower frequencies. The amount of subcarrier placed near the high end mation contained in the 3.58 side - tilt necessary to compensate for the of the video passband. This sub - bands and filters out the unwanted IF attenuation (Fig. 2A) of the carrier is used to generate color - monochrome (B/ W) portions of the higher color frequencies is shown in signal sidebands through a two- video signal. This stage is similar to Fig. 2B. The resultant over-all res- phase modulation system at the TV most wideband IF amplifiers with ponse of the amplifier is shown in transmitter. In effect, two chroma adjustable input and output. It is Fig. 2C. components, having the same fre- normally tuned to a center fre- Many bandpass amplifier stages

41 ELECTRONIC TECHNICIAN Know how chrominance circuits work and make your shop the 'official color center' in TV your area def Vag Z. Vondeg

FROM VIDEO DET V 70IA T701 '26GHBA SAND PASS BAND PASS TRANS. r0A r260V vw I/2 NOS c IV MONr NO TO DEMOD

TO B -Y DEMOS

270v B.

KILLEF PLATE 14CV B

FROM VIDEO AMP TO BLANKER CATHODE BURST KILLER KILLER GRID AMP PLATE

in Zenith 25MC30 television Fig. 3-RCA CTC 17 color chassis single stage bandpass amplifier. Fig. 4-Two stage bandpass amplifier used receiver.

to cut it off while the color burst former secondary, consisting of 3.58 pulse is being received. This pre- Mc sidebands, is applied to the de- 8-Y BALANCED MODULATOR vents color information from ap- modulators through the color con- 58 MC pearing on the CRT during horizon- trol. The set owner can vary the SUB -CARRIER color saturation with this front panel 90° PHASE COMBINED tal retrace. SHIFT OUTPUT A color killer circuit is also used control. to cut off the bandpass amplifier Besides amplifying the color side - are per- R -Y BALANCED when B/W pictures are received. bands, two other functions MODULATOR This prevents spurious noise from formed in this stage: When color reaching the CRT. Without the color signals are absent, a negative dc the voltage is developed on the color Fig. 5-Block diagram of a balanced modulator killer, noise would appear on employed in a two phase modulation system. set's screen as colored dots or dashes killer plate and fed through the de - -adversely affecting B/W recep- coupling network (R752 and 0702) tion. to the tube grid. This cuts off the Now let's look into the detailed stage and prevents noise from reach- in modem color receivers use ACC circuit functions of an operating ing the CRT during B/W transmis- (automatic color control). ACC is bandpass amplifier. sion. High positive pulses from the similar to AGC in a monochrome blanker stage are also applied to Stage Bandpass Amplifier receiver and its bias is dependent Single the cathode - cutting the tube off on the burst signal amplitude which A single stage bandpass amp- during the burst interval. signal lifier used in an RCA CTC 17 color is varied by the incoming Two -Stage Bandpass Amplifier level. The ACC voltage tends to chassis is shown in Fig. 3. Signals make the color circuit's output in- from the video amplifiers are A two -stage bandpass amplifier dependent of signal variations. But coupled to the bandpass amplifier used in the Zenith 25MC30 color because individual color tastes vary, grid through L-701. The combina- receiver, for example, is shown in video signal provision is made to manually ad- tion of this coil, the coupling capac- Fig. 4. The composite out- just picture hue and saturation. The itor, C132 and the interelectrode is taken from the video detector a 4.5 Mc hue adjustment is usually accom- capacitance of the tube, form a put. After passing through plished in the color sync section. In tuned circuit which resonates at trap, this signal is coupled through to the most cases, saturation is adjusted by about 3.58 Mc. a 7 pf coupling capacitor This ca- varying the bandpass amplifier gain. The plate load, transformer T701, first color amplifier grid. A horizontal blanking pulse is is double -tuned and has a response pacitor passes all frequencies above lower also applied to the bandpass stage of at least 1 Mc. Output at the trans- 3 Mc and blocks all frequen-

49 MAY 1965 ldB- mc sUÓC°rrÍ!/ fsub GPJYou and Color TV

Fig. 6-Simplified diagram a NO-SIGNAL of synchronous AVERAGE PLATE AVERAGE PLATE NO-SIGNAL demodulator. AVERAGE PLATE CURRENT\ CURRENT\ AVERAGE PLATE CURRENT CURRENT

pup,Aid ------Fig. 8-Output voltage versus phase difference between color signal and 3.58 Mc signal applied to a color demodulator.

90° OUT -OF OUT -OF -PHASE - IN PHASE PHASE SIGNAL SIGNAL SIGNAL / ON GRID ON GRID REINSERTED ON GRID SUBCARRIER ON SUPPRESSOR GRID

A B C D

Fig. 7-Average plate current for various phase relationships of the two signals applied to a demodulator circuit. cies. The 4.5 Mc trap prevents the first stage with a high gain pentode, In developing compatible color 4.5 Mc sound frequency from af- a 6KT8, having no cathode bias. TV standards, the National Televi- fecting the color output. This fre- R36, a front panel control, varies sion Systems Committee (NTSC) quency can cause an objectionable the second stage gain. This control found it desirable to transmit color 920 kc beat interference on the is used to adjust color saturation. information in the existing 6 Mc CRT. Choke L18, in parallel with R36, wide channels without having to ex- The single -tuned plate load (L17) prevents phase shift when the resist- pand the bandwidth. In B/W trans- of V6B and the double -tuned trans- ance is changed. mission, video information appears former (T10), are adjusted for the The second amplifier grid is con- in sideband clusters around the har- correct frequency response of the nected through a decoupling net- monic frequencies of the 15,750 two stages. Coil L17, combined work to the color killer plate. When cps horizontal sweep frequency. This with tube and circuit capacitances, B/W is being received, a high nega- leaves many open spaces in the fre- resonates near 3.1 Mc. T10, the tive voltage is generated at this quency spectrum. These "holes" in plate load of the second stage, acts point. This voltage cuts off the the spectrum are used for transmit- as a trap at 3.6 Mc - broadening second chroma stage during B/ W ting color information by "nterleav- the response in this area. The out- reception. ing" it between B/W video infor- put of T10, going to one demodula- During retrace time, blanking is mation. This is accomplished by tor, is tapped. During transmission, accomplished by applying a positive shifting the horizontal scan fre- color signals are reduced by unequal pulse from horizontal discharge tube quency in color transmission to 15,- amounts to prevent overmodulation. cathode through T10 to the de- 734.264 cps, (vertical rate 59.94 This tap restores the two chroma modulator grids. This causes the cps) and choosing a subcarrier fre- voltages to equal amplitudes. tubes to conduct heavily and lowers quency of 3.579545, an odd multi- ACC action is introduced at the the plate voltage. This cuts off the ple of one half of the horizontal first amplifier grid. This is accom- CRT grids during horizontal retrace sweep oscillator frequency. plished by tying the killer tube grid time. The subcarrier chosen is modu- to the first stage grid. The voltage lated by balanced modulators with at the killer grid varies with burst - Demodulators two different chroma signals, known pulse amplitude. Thus, the amplifier Action of the demodulators can as B -Y and R -Y. How these signals gain varies with the strength of the be described more easily by review- are produced will be detailed further burst pulses. ing transmission principles a little in a forthcoming article. To sim- Maximum gain is obtained in the more in detail. plify, for the moment, the theory of

50 ELECTRONIC TECHNICIAN oe GREEN GRID PILO 6GY6 uVT.î RTSI 'a:'OEMOD. OS 3(R-YJAMP. 39.0 G2oyh ZIOR ,Ilq. IOOK 105 E arov c AA RED GRID y .036 I FROM - z BANDPASS

358MC BLANKER 270vB+ 40508+ OSC PLATE PHASE DET 3.58MC OSC

used in Zenith 25MC30 color chassis. Fig. 10-Demodulator and color difference circuitry used in RCA Fig. 11-High level demodulator CTC 16 color chassis.

are combined and the resultant am- modulator stages do measure the re- plitude modulates the main picture sultant voltage at a prescribed time. carrier. Without going into vectors As the subcarrier was suppressed at this point, the time relationship at the transmitter, it must be rein- between the two signals is main- serted before demodulation can tained during their path through the take place. The carrier is generated transmitter, through the air and by a local 3.58 Mc oscillator. This into the receiver. The RF and IF oscillator is controlled by the pulse stages amplify the composite signal of sync information that was trans- containing the color components. mitted. This then duplicates the Fig. 9-A typical B -Y, RY synchronous The signal is detected and applied time (or phase) relationship that demodulator. to the video amplifiers and on to existed between B -Y and R -Y at balanced modulators (Fig. 5) we the bandpass amplifier. The band- the transmitter. Herein lies the key can say that the B -Y signal is ap- pass amplifier removes the bright- to proper color information decod- plied to one modulator at a given ness (B/W) components and pre- ing. The 3.58 Mc local carrier acts time and the R -Y signal is applied pares the color signal for the de- as a switching voltage for each de- to the other modulator at a different modulators. modulator tube. The tubes are time (or difference in phase) . The signal at the demodulator switched on and off at the proper Hence, we will have a series of side - grids is a duplicate of the resultant times. A phase shifting network is bands of the 3.58 Mc carrier at combination of the modulated B -Y used to introduce a 90 deg phase each modulator output. The voltage and R -Y color information present (time) difference between the B -Y at one modulator output lags the at the transmitter. We are now in- and R -Y switching voltages. This is other by a given amount of time. terested in recovering the individual call synchronous demodulation. If we now synchronize the re- color signals. This is done by a cir- A simplified diagram of a syn- ceiver with these signals, we then cuit called a demodulator or de- chronous demodulator is shown in have a time base from which the coder. Fig. 6. The resultant color signal is receiver demodulators can operate. We recall that the time relation- applied to the control grid and the This sync information is transmitted ship between the two color signals 3.58 Mc subcarrier signal from the in the form of a sharp burst pulse is the same at the receiver as it is local oscillator is fed to the suppres- consisting of about 8 cycles of the at the transmitter. If we can meas- sor grid. A color receiver requires subcarrier frequency. This pulse ure the resultant voltage at the same two of these circuits, one for each (color burst), when processed at relative time (or phase) we will color difference signal. the receiver, assures that the B -Y have a voltage at the B -Y demod- Demodulator action can be ex- demodulator is operating when B -Y ulator plate varying at the same plained with the aid of the wave information only is present in the rate as the B -Y voltage at the trans- forms shown in Fig. 7. The no chroma signals and the R -Y de- mitter. By the same token, the R -Y signal condition is shown in Fig. modulator is active when only R -Y demodulator plate voltage will du- 7A. With the subcarrier present on information is present. plicate the R -Y voltage present at the suppressor grid and no signal Outputs of the two modulators the transmitter. In effect, the de- Continued on page 88

51 MAY 1965 QTips on Color

4 Z. G pau

If you've been servicing color turn, determines the point where the Gray Scale Tracking TV sets regularly for some time, high voltage begins to bog down and The aforementioned screen ad- you're thoroughly familiar with con- the raster blooms. Consequently, if justments are a part of the gray vergence, gray scale tracking, etc. we can set the screens at a higher scale adjustments which gives us a But few of us are so good that an bias point, maximum brightness will B/W picture over the entire gray extra "kink" or two wouldn't be then occur closer to maximum rota- scale range. The drive controls also helpful at times. tion. have an important part in the end I've been servicing color since the Normally, the screen controls are result and technicians must know first sets trickled off the production set by placing the CRT bias switch what to look for if optimum results lines. During that time I've picked to its highest position (minimum are to be obtained. up some tips that most technicians brightness) and then the screen con- The drive controls are normally could use on house calls and on the trols are adjusted for proper cutoff. set center -range while the screen bench almost every day. So, for This is accomplished by first setting adjustments are being made. After what my experience is worth, here the service switch to SERVICE. You the screen adjustments have been goes. then turn all three screen controls completed, the drive controls are to minimum. Each control is now then adjusted Blooming to compensate for turned up until the colored line is color tints in the picture highlights. Most color sets have a tendency visible. And finally, each control If an IF tube is removed, the tint to bloom near the end of their is backed down again until the line of the raster can be viewed without brightness control range. Some sets, just disappears. interference from noise or video, however, bloom too early and the If the highest usable brightness and by turning the brightness from usable brightness range is limited to level occurs at too low a point it a very low level to a high level, gray as little as a quarter of a turn. can be increased by following the scale tracking can be observed. (Re- The set owner is the first to com- same procedure - but the CRT moving an IF tube is also a good plain of this and the last to under- bias switch must be set to its highest idea when adjusting the screen con- stand that it's difficult to do any- brightness position for set opera- trols.) thing about it because of a combina- tion. If the maximum brightness If the screen controls have been tion of set and CRT characteristics. level is not reached when the bright- properly adjusted, low-level color But wait, it's not quite that bad! ness control is set full clockwise, should be gray. When the bright- Screen adjustments are the key adjustments can be repeated with ness is advanced to a high level, controls in determining how much the bias switch in its center position the screen should also remain gray. current the CRT will draw. This, in for the screen control adjustments. If it turns blue, then the blue drive

FLYBACK

3A3

6BK4 SHUNT REG IF TRANS

SOUND TRAP Ist VIDEO 400v VOM (4.5mc) AMP

Fig. 1 - Current check on shunt regulator is important for 6BK4 Fig. 2 - The 4.5 sound trap can be easily adjusted by observing shunt regulator tube. the waveform on a scope at some point beyond the trap.

52 ELECTRONIC TECHNICIAN Servicing

Take a lesson from this old color pro - he says experience is still the best teacher

control should be decreased. If the the yoke in a cocked position while screen turns green, the green drive you tighten it but, quite frankly, control should be decreased. Fi- you have no choice. At present all nally, if the screen turns red, both rectangular tubes are more critical the blue and green drive controls than the recent round tubes and it should be increased. it may take twice the time to set Drive adjustments normally have them up until you get used to the little effect on the low brightness new "quirks." level tint but it should be screen High Voltage and Focus checked after the drive adjustments. Dominant colors in the low level Setting the high voltage properly brightness should be counteracted and getting the best focus are two by increasing or decreasing the ap- problems which bother technicians propriate screen control slightly. as much as any other. Interestingly enough, they are very closely re- Purity lated because, with improper high Getting a good clean red screen voltage, attaining good focus will can be a mighty tough job on some be virtually impossible. sets. And the 25 inch sets are even The high voltage on most sets tougher than the 21s. Generally, a should be 24 kv. On some new sets little more care in each of the nor- 25 kv is specified. The high voltage mal steps will get you a little closer should never be less than 1 kv under to the purest possible screen. the specified figure; that's less than One of the most overlooked steps 5 percent tolerance. Understanding Fig. 3 (Top) - 4.5 Mc trap mi,adjusted, RF in waveform. /i test pattern with is degaussing. Now that automatic this, you can see why it's very im- showing a 400 cps tone was used as, a signal, (Bottom) degaussing is available, some tech- portant that your meter is accurate. - The same signal with the crap properly nicians have eliminated this step en- If you use a multiplier -type probe adjusted for minimum 4.5 Ms RF. tirely from their set-up procedure. on a general-purpose VTVM, have This will not give the most desirable it checked against a good electro- results. In fact, it may be totally static high voltage meter if at all impossible to get a reasonably pure possible. screen without first degaussing. Too much high voltage is rarely Those who remember the diffi- a problem. About the only faults culty in obtaining purity on early generated by too much high volt- color sets should have little trouble age are frequent shunt regulator adapting themselves to the 25s. For high voltage rectifier failures and best results these sets should be insulation breakdown. Manufactur- degaussed as usual - whether or ers' recommended procedures for not they have automatic degaussing high voltage set-up includes a cur- - on both the inside and outside rent check through the shunt regu- of the cabinet. This may seem like lator (Fig. 1) . This should not superfluous motion but it will get present a problem unless an error you better results in most all cases is made in procedure. and in some cases will make the It will not be possible to obtain difference between acceptable and good focus unless the high voltage unacceptable pictures. is properly set. And even when the Purifying the 25s also calls for high voltage is properly set, the fo- some of the "yoke -cocking" asso- cus may change slightly with Fig. 4 (Top) - With conventional signal from ciated with early sets. It may seem brightness adjustments. To mini- the station and showing 4.5 Mc trap mis- adjusted. (Bottom) - Properly adjusted 4.5 to take three hands at times to hold Continued on page 84 Mc trap using station signal.

53 MAY 1965 Spray It... Renew It!

Use these inexpensive service aids properly and speed your troubleshooting and repair work

Aerosol -type service aids - Cleaners cleaners, cleaner -lubricants, high di- This group can be subdivided electric coatings, refrigerants and roughly into three presently avail- solvent-lubricants - are modern, able types. No doubt other types chemical spray -can products that do will be developed for additional spe- a consistently effective job when cific purposes. One product is de- used properly and they save valu- signed to remove oxide and tape lu- able service time; which is the same bricant deposits from tape record- thing as money. We can speak er heads and another has been de- knowledgably too of some liquid veloped for cleaning and reducing plastic cements although not pack- "static" build-up on TV safety aged in aerosol cans. All are used glasses, CRT face -plates, cabinets by most successful service shops we and phonograph records. The third No Arc by have observed in recent years. Chemtronics, Inc. item is a "dry" hand cleaner con- Clear and Quiet by GC Electronics. But some technicians have com- taining lanolin and germ-killing plained that prices are generally too non -irritating chemicals. Some high on these products. Actually, brand names include: Glass -Mate, Hi when used properly, they pay well Kleen-Vue, Lens-Kleen, Mark - and the relative cost is nominal. N-Glas, Mask -Glas and No -Noise In some cases, the "high cost" com- Tape-Reco. plaint arises from over -application and waste. In other cases these Cleaner -Lubricants products have been selected indis- This category can be subdivided criminately - the incorrect product into a number of somewhat similar being used on a given job. Most products, some recommended for Spraáreece by W. E. Metzler Co. products conform to military speci- specific purposes by their manufac- fications and state-of-the-art de- turers. The various products may velopments. be used for cleaning and lubricat- Aerosol-type spray -can products ing electrical contacts-contacts that may be roughly divided into five oxidize and develop semiconducting categories as follows: cleaners, surfaces - preventing normal elec- cleaner -lubricants, dielectric coat- trical contact. Applications include ings, refrigerants and solvent lubri- TV tuner contacts, carbon potenti- cants. ometers, relays, multi -band switches, push-button assemblies and many others. All products are exception- ally economical and effective - when applied with a quick "swish" by momentarily pressing the can's tlasti Patch by Colmar Electronic Products, push-button. Some brand names in nc. this area are: Clean -and -Quiet, Con- tact Kleen, De-Ox -Id, EC -44, Hush, Duelspray by Quelcor, Inc. Jif, Kleen, Kleen-Tune, Merit- Lube, No -Noise, Ox -Nos, Quiet - role, Spra-Kleen, Trol-Aid, Tun- O-Lube and Shield. The aforementioned cleaner -lubri- cants are not all formulated the same and some contain oils with No Noise Tape -Reco by Electronic Chemical solvents, some are siliconized. Corp. Continued on page 98

54 Transistor Circuit Fundamentals

Eliminate functional details, understand basic operation and make your troubleshooting and repair jobs easier

4 WatiaHm 99aKgee«gez 57z,

as an amplifier or as an oscillator. Many technicians successfully re- pair tube-type TVs and radios with- In either an NPN or a PNP out knowing precisely how an elec- transistor, the lower diode - the tron tube operates. They know only C C one equivalent to the transistor's that an increase in tube grid voltage emitter junction - must be for- causes increased conduction with a ward biased and connected so the consequent lower voltage on the B current flows easily through it. The plate and vice versa - when there's top diode must be reverse biased. sufficient voltage on the plate and a In other words, it must be connected closed loop exists through the tube's so current will flow only through cathode. And it is doubtful if a good E E it by leakage. (See Fig. 3 and 4). benchman will ever find it necessary PNP NPN Normally, the emitter junction to consult an expert on space - the lower diode - is forward charges. Fig. 1-A transistor is equivalent to diodes biased by only 0.2 v or so. And this wired back to back. is an important measurement. This Simplified Approach bias is measured from the emitter Transistor theory has been com- ture of these units; we'll assume, to the base. If the applied voltage plicated by volumes of text ma- as scientists do, that certain things forward biases the diode more than terial focusing on the physics of are relatively true. To begin with, 0.2 v the transistor will be satu- operation (primarily useful in solid- we'll assume that current flow is rated. If the voltage is less than state design and manufacturing). the reverse of electron flow. And 0.2 v the transistor's emitter junc- Transistor knowledge has been ad- we'll stick to "current flow" in this tion may be cut off or tend to cut ditionally complicated by manufac- discussion to eliminate a more com- off on signals which drive it in turing transistor types that operate plicated discussion of "hole" theory. that direction. Electrically, a transistor is equiva- similarly, but which have opposite Polarities polarity power voltages. lent to two diodes wired back to I have been confused many times back. This is shown in Fig. 1. The Since you've read this far you while engaged in design work and NPN is shown with its "plates" are probably wondering about the in troubleshooting. Hence, I have tied together at their junction and polarity difference for NPN and found it necessary to develop a sys- the PNP is shown with its cathodes PNP transistors and how you can tell tem to keep the "little devils" in tied together. Now, although this the polarity of various biases applied line and help me remember what is a long way from being a tran- to the transistor. It's very simple. to expect in the way of circuit volt- sistor, it is all we need to know We know that the emitter junction ages which appear on NPN or PNP about its construction. Actual tran- is always forward biased and the types. sistor symbols are shown in Fig. 2. collector junction is always reverse Note that the arrows in the tran- biased. This is true for both NPN NPN/ PNP sistor symbols point in the same and PNP transistors. First, let's understand what NPN direction as the diode equivalents. Now here's a trick to remember and PNP means. It will not be nec- Now lets see how a transistor which will help you to determine essary to go into the atomic struc- must be wired in a circuit to work which type transistor should be con -

55 MAY 1965 C C

B

E E PNP NPN Fig. 2-PNP and NPN transistor symbols. 0 co ONLY

Fig. 8-Even with voltage on the collector it is reverse biased. Leakage current flows through the collector with the base at the emitter potential only. Fig. 9-Simple biasing system.

Fig. 3 (above) Fig. 4 (below) shows how PNP and NPN transistors are biased.

nected to a positive voltage supply the emitter potential, only leakage and which is connected to a nega- current flows through the collector. tive voltage supply. We only have to look at one transistor junction Blas and Stabilization at a time. When the N section of the Even when proper voltages and junction is connected to a nega- polarities are applied to transistor PNP NPN tive voltage and the P is connected elements, the transistor will not to a positive voltage, the junction is function properly unless the volt- forward biased. (N for negative ages are proportioned properly. P for positive) This is the job of the biasing net- By applying this to a PNP tran- work. Biasing networks are in sev- sistor in a normal circuit configura- eral forms but the purpose of each tion we can see that if the emitter is the same: to maintain operating is grounded, a small negative volt- voltages which will allow the tran- age will have to be applied to the sistor to operate linearily over the base and the collector voltage will desired range and under normal Fig. 5-Basic biasing of PNP and NPN tran also be negative. (Remember, the signal conditions without being sistors. collector junction is reverse biased.) driven into cut off or into satura- The circuits for both PNP and NPN tion. transistors are shown in Fig. 5. A stable network must be cho- Now let's see how this is done in sen as well since drifting biases can actual practice. The circuit shown cause changes in the output linear- in Fig. 6 is a common emitter cir- ity, amplitude, etc. Even more im- cuit which is analogous to the com- portant, slight bias changes can mon amplifier or grounded cath- cause an increase in collector cur- ode tube circuit. Note that only one rent which raises junction tempera- battery is employed and that R1 ture, in turn causing a further in- and R2 form a divider to set the crease in junction temperatures and base at its proper bias level. greater collector current. This type With the proper forward bias, of feedback (thermal runaway) current flow in the collector emit- eventually causes transistor destruc- I:ig. 6-Common emitter circuit. ter circuit is very heavy. A small tion. percentage of the emitter current The simplest type of bias is flows in the base lead. In most shown in Fig. 9. When a great deal transistors, more than 95 percent of of drift and non-linear frequency the emitter current (which is con- amplification can be tolerated, this trolled by the base bias) flows in arrangement can be satisfactory if the collector circuit. This is shown the bias can be 'adjusted for the tran- in Fig. 7. Fig. 8 demonstrates sistor and the ambient temperature Fig. 7 (A)-A large percentage of the emitter that even though the collector has can be controlled. current flows in the collector circuit of a PNP normal potential on it, it is indeed This same bais scheme can be transistor. (B)-Similar flow in an NPN tran- aistor. reverse biased. With the base at employed however, with stabiliza-

36 ELECTRONIC TECHNICIAN 4- Fig. 10-Circuit for eliminating degenerative feedback while maintaining stability.

Fig. 11-Voltage divider bias system which places increased drain on the battery.

tion, by simply connecting the bias that one circuit is better for low resistor to the collector terminal. noise while another has a better With this method, when the tran- amplification factor need not con- sistor current increases the collector cern the average TV technician. voltage drops and a corresponding The same phase reversals found drop at the transistor base tends to in certain tube circuits are also overcome the increase and stabilize found in transistor circuits. This is the transistor current. shown also in Fig. 12. Note that The aforementioned bias method the common emitter circuit causes tends to cause degeneration. Since a 180 deg phase shift while the this is frequently desirable - to common base and common collec- increase over-all stability and fre- tor circuits present no phase shift quency response - it causes no between the input and output. problem. A circuit shown in Fig. The impedance of transistor cir- 10 eliminates the degenerative feed- cuitry is, by nature of the device, back while maintaining the good very low. In some circuitry, the im- stabilization qualities of the degen- pedance is sufficiently low so that erative circuit. Filter values in this output transformers to speakers can circuit will not interfere with any be entirely eliminated. Input equip- frequencies that are to be amplified. ment must in many cases be adjusted Another common circuit is shown for the low impedance too. Cir- in Fig. 11. This is actually a simple cuits have been designed, however, voltage divider. A disadvantage of that have input impedances equiva- this circuit is the increased drain lent to vacuum tube circuitry. placed on the battery by the divider Technicians that have finally bleeder current. awakened to the fact that transistors are not just a passing engineers' Practical Circuits plaything still do not realize just Just as tubes have three basic how close the transistor is to their circuit configurations so do tran- service bench. Soon transistors will sistors. They are: common emitter, be appearing in larger numbers in common collector and common TVs. Already they are being suc- base. These are equivalent to the cessfully used in "tinyvision" and common cathode or standard ampli- TV tuners; next year we are sure fier, the common plate or cathode to see them in several regular TVs. follower and grounded or common Although the information given grid circuits respectively. All three here will not provide you with all basic configurations are shown in the knowledge you need about tran- Fig. 12. Each of these circuits will sistors, if you know this much well, be found in circuitry where the par- you'll have no trouble repairing all of the tough Fig. 12 (A)-Common emitter. (5)-common ticular characteristics of that con- but the "doggedest" collector and (C)-common base transistor cir- figuration is best suited. The fact dogs. cuits.

57 MAY 1965 Service Seminars For 2 -way Radio

Space Age advances force technicians into continuing educational programs

RCA's J. R. Alexander explains new techniques required to service transistorized mobile radios. Live demonstrations 'prove out' new tech- niques.

Modifications in basic two-way penses limited to short distance trav- design are forcing service techni- el, can gain technical knowledge cians to keep abreast of new de- for servicing advanced transistorized velopments. The traditional instruc- units in a highly productive and ef- tion -book -oriented approach to ficient manner. equipment service is inadequate for A typical one -day seminar usu- independent service organizations ally covers circuit descriptions of and self-servicing users. advanced mobile units, alignment New techniques are required to procedures and installation/servic- service advanced units containing ing precautions and how to use test modular, noise suppression, highly meters. Transistor servicing, noise selective and stable circuitry. Spe- clipper and selective calling decoder cial seminars or "clinics" are being circuits are covered. sponsored by manufacturers. Comments received from service Technicians tune and align live units to get One service seminar, scheduled "clinics" indicate that the technical the feel of advanced equipment. in major cities from coast to coast, rundown on advanced equipment is is sponsored by RCA's Mobile Com- of great value to field technicians munications Department. Under the who find it difficult to keep abreast direction of J. R. Alexander, man- of the many technical changes in ager of field service, the service mobile equipment. Technicians can seminars give technicians an oppor- obtain complete information and tunity to learn more rapidly than a schedule of cities to be visited by would be possible from home study writing to RCA, Mobile Communi- alone. Local technicians, with ex- cation Products, Camden 2, N.J.

58 ELECTRONIC TECHNICIAN Color TV HORMONTAL e;) Problems

Get acquainted with the new clues that point the way to various trouble areas

4 Mary Sae

Horizontal deflection systems of color receivers cates high voltage is getting to the CRT. This crackling differ from those in B/W sets only to the extent that is the magnetic attraction of the harness holding the the systems in color sets supply convergence pulses CRT in place, and assures us that high voltage is and focus voltage. Schematics of B/ W and color being generated. If there's no crackling sound, then flyback systems are shown in Fig. lA and Fig. 113. chances are no tubes are involved and the trouble If you want to establish and maintain a solid relation- exists elsewhere. ship with those customers who will be switching to Leave the new tubes in the set until the problem color, you'll have to learn how to eliminate trouble has been solved and don't jump to the conclusion at this in these systems quickly and effectively. point that the flyback or yoke is faulty. These two components may very well not be involved. Clue Number One Number Three A common peculiarity of many current color re- Clue ceivers is that audio comes on before the raster appears. After the receiver has been on for several min- This is caused by slower heating of horizontal tubes. utes (not over five) , observe the horizontal amplifier But the appearance of clear audio indicates the keyer tube. If its plate turns cherry red, then the problem (AGC) is operating normally, video information is pres- is most likely being caused by one of two things: ent in the IF strip, and the horizontal oscillator is func- saturation in the flyback system or low B+. tioning. Like the B/W receiver, the color set's HOT will Allow the set to warm up fifteen to thirty seconds. run red hot if it is underdriven. But unlike the B/W Turn the brightness control about two-thirds of the tube, it can be fully driven, have normal grid bias and way up, the contrast half way down, and decrease the still saturate. This is a major difference between color volume so it's just audible. If the screen fails to light, and B/W sets. Any loading in the flyback system of unplug the receiver and while it's cooling, substitute a color receiver will cause the HOT to draw too much known -to -be -good tubes in the horizontal oscillator, the current - a grim destroyer of both flyback and damper, HOT, HV rectifier, regulator and blanker tube! stages. If B+ is suspected, and the receiver uses silicon rectifiers, cut one end of each rectifier loose and tem- Clue Number Two porarily solder in new rectifiers. If rectifier tubes are Standing close to the rear of the receiver, plug it used, replace them. Check B+ again. Still no sat- in and listen for the soft crackling sound that indi- isfactory results? Then we move on to:

59 MAY 1965 6DQ6 6DQ5 6BK4 IJ3 3A3

IV2

FOCUS YOKE ÓDE4 BOOST AGC

HORIZ BLANKING E' YOKE YOKE (PULSE WINDING) ITT . BOOST PULSE WINDING 6AU4

Fig. 1 (A) - Black -and -white flyback system. (B) - Color flyback system. Note similarity of both. Focus and regulator circuits are different in color sets.

Clue Number Four age will be developed if either of these is shorted. The crackling sound that revealed high voltage will Disconnect one end of each diode and check for not necessarily indicate, for example, that the HV is arc. If no arc or a small arc, forget about the diodes. decaying gradually. Remove the HV rectifier cap Reconnect them. and try drawing an arc with an insulated handle screw- Step Number Two driver. Do not touch the tool to chassis as it may damage the flyback. If the arc is less than 11/2 in., Check for boost. Keep the probe on the test point prepare to remove the chassis, or if the receiver has a while the set is warming up. The boost voltage may bottom plate, stand the cabinet on end. This will up- start to build up and immediately collapse. If this hap- set purity and possibly convergence, but both of these pens, then it should be evident that a capacitor across should be checked anyway after all servicing. the efficiency (linearity) coil is shorting. If you check At this point, disconnect the convergence yoke for boosted boost or focus voltages, use a high voltage plug, and forget all other tubes in the receiver and con- probe because we're dealing with 1100 to approximate- centrate on all parts directly involving the flyback sys- ly 5000 v. tem itself. If necessary, and if it's a clip- or plug-in If either of the efficiency capacitors is rated at 600 v, type, the tuner can also be disconnected. It will have replace them with identical values rated at 1000 v. If inconsequential bearing on the problem. Do not be the set is over two years old, they may be thermal, concerned with the convergence panel because there's and replacement may eliminate a future call-back. little chance that it has anything to do with the trouble. The horizontal windings of the yoke must be connected Case Histories to gain full sweep voltage. A Packard Bell, chassis 98C7D, was kicking out the circuit breaker. The damper was arcing badly, so Troubleshooting Step One - it was replaced. This, however, did not produce a Leave the cap off the HV rectifier. Look at the raster, nor was there any crackling sound of high volt- schematic of a color receiver using two special high age build-up. Two minutes later the 6JE6 plate turned voltage silicon rectifiers as shown in Fig. 2. One is cherry red. for boosted boost, the other for focus. No raster will This receiver has a vertical chassis which can be appear if either of these diodes is open. No high volt- swung out to get at its innards. The HV cage is easily

60 ELECTRONIC TECHNICIAN T4

3A3

.01

-_ ( FOCUS REGT -I.SM MI O DO) 113Opf P C20 6K /o

HORIZ G O FC CI O CENTERING BB IOOK O OF C2 IOa YOKE ?2W 01 T4 TERMINAL BOARD FC BOOSTED M2 BOOST --EFFICIENCY BOOST BB RECT BOOST CI00^ 068 f '¡ 1. YOKE 6DW4 1 .08 CI01 TO BB BO

of Packard Fig. 2 - Schematic of focus and boosted boost section Bell 98C7D chassis. C100 was shorted out.

the badly burned effi- removed from the back by experienced technicians. moved. First thing noted was That indicated seri- The horizontal layout of this receiver and the fly- ciency coil. It was replaced. with the possibility of back terminal board is shown in Fig. 2. The boosted ous load-down had taken place, boost rectifier and linearity capacitors are located un- the flyback being damaged. to conclusions, a capacitor der the chassis below the convergence plug. The focus But rather than jump The cap of the 3A3 was left rectifier is located on top of the flyback. "sub -box" was readied. of solder placed about a By checking the schematic, we note that boost is hanging, with a metal coil As each filter was jumpered, obtained at point BB. In this case, no boost voltage half inch away from it. an eye was kept on the HV cap. Finally, when the existed. jumpered, an arc took Further checking revealed that two capacitors, choke output electrolytic was Replacement of the electrolytic C100, C101, were connected from this point to the off to the solder coil. operation; no damage to the flyback efficiency (linearity) coil and that a resistance reading put the set into from "BB" to the plate pin -contact of the 6DW4 at all. here is that we had reverted right back to showed a low resistance continuity. Removing the The point servicing procedure. Obviously, chassis screws and swinging it out gave clear access to common-sense B/W of the original electrolytic had shot the bottom side. C100, 0.068 µf, was shorted. Re- the power factor the to drop enough to pre- placing it with a 1000 v capacitor of the same value sky high, allowing B+ of boost and high voltage. All eliminated the problem. vent proper build-up the tubes were put back, with eventual replacement of A Simple 'Toughie' the 6DQ5 to get proper width. A Zenith, chassis 29JC20, CU, didn't have over Other Causes a thousand volts at the cap of the 3A3. Tubes were stage's substituted, all normal resistance and capacitance read- As you already know, the last video amplifier in a color re- ings were checked. Boost was riding at 700 v when grid is the source of brightness control A bad 850 v was specified. B+ seemed normal at 375 v. ceiver. Failure of this tube will kill the raster. in some Just to make sure, the two 3DG4s were replaced. regulator, weak high voltage rectifier, and serious bloom- No change. cases a bad blanker tube, will cause The cabinet was up -ended and the bottom plate re - ing.

61 MAY 1965 TOTAL MECHANICAL 330" ROTATION (NOMINAL) Choosing

ELECTRICAL ROTATION (NOMINAL) 4 ?4' uca# ltd k s Centralab, Electronics Div. Globe -Union

CT 30

Fig. 1 - Electrical and mechanical rotation definitions for the popular 15/16 in. dia composition controls. The 50 percent electrical rotation Fig. 2 - Bushing point is 180 deg nominal from the CCW end or 150 deg nominal mounting controls. from the CW end (shaft end view).

By properly choosing and using "off -the -shelf" re- Occasionally service placement controls, shafts and accessories stocked by technicians will encounter your parts distributor, you can save time, money, in- non-standard resistance ventory space and capital, and even reduce your con- values which have no off - sumption of headache pills. the -shelf replacement. As a general guide, most TV receiver manufacturers Since the wide tolerance adhere to the resistance tolerances standardized by the of ±20 percent or ±30 Electronic Industries Association (EIA) for variable percent was used in these composition resistors. Controls up to 100 K generally original controls, it would have a tolerance of ± 20 percent and all above 100 K seem logical that a replacement having a slightly higher are generally ± 30 percent. In many instances, the or lower nominal value would cause no difficulty. This original receiver manufacturer will use ± 30 percent would hold true in the case of volume controls, where on the very low values. at full -on-volume, a higher nominal value would result Measurements and Tolerances in a slight increase in over-all gain, while the use of a lower value would result in a slight loss. When controls When measuring the resistance value of control at are used as voltage dividers and rheostats, however, mid-rotation point it is important to remember that the safest substitution would be to choose a replace- the EIA standards allow ± 3 percent rotation tolerance ment whose nearest nominal value is higher. (approximately ± 9 deg). In addition to this, the 50 In choosing tapped volume control replacements, percent rotation resistance value can vary by the ± 20 two important things must be considered: percent or 1) The ± 30 percent tolerance of the control. nominal resistance at the tap of the replacement Furthermore, nearly should all the off -the -shelf replacement be close to the original, and 2) the same physical loca- controls are designed to be used with or without an tion for the tap on the resistance element is essential. OFF/ON switch. Hence, the resistor element is designed This is necessary so the automatic bass compensation with a zero resistance over the nominal 30 deg area designed into the original set can be accurately dupli- required to actuate the switch. This means that the cated. Because of the broad variety of taps and resis- effective electrical rotation begins at approximately tance used in original equipment, it is not always possi- 30 deg clockwise from the CCW end (measured from ble to find the exact replacement needed. the center terminal), A very whether or not an OFF/ON switch simple method of obtaining a closer tap resistance is attached. Inasmuch as the nominal total mechanical match for a single tap control is to choose a dual tap rotation is 330 deg, the total effective electrical rota- control, one tap to closely match the desired resistance. tion is 300 deg (330-30). Consequently, the effective The extra tap is disregarded. electrical mid -rotation point would be 180 deg clock- wise from the center terminal or 150 deg counter- Bushing Mounting Controls clockwise from the right terminal. This, in effect, Bushing mounting controls shown in Fig. 2 are means that the internal contact wiper arm would be currently popular replacements in 1/2 w, 15/16 in. diametrically opposite the center terminal at 50 percent diameter. Until recently, the shafts available were of electrical rotation. This can be clearly seen in Fig. 1. various combination mill types and in lengths which

62 ELECTRONIC TECHNICIAN and Using Controls

Save time, money and aspirin when replacing controls, shafts and accessories

Jjiil,r,r

Fig. 3 - Size range of one typical 1/4 in. shaft. replace- enabled cutting to the specific length required. Un- large enough to accommodate a bushing type fortunately, cutting off and de -burring shafts involves ment. If a bushing type replacement is used, it is rec- be in- time and time means money. ommended that a "plug-in" insulated shaft Exact length shafts for replacement in dual con- stalled to eliminate possible shock hazards. centric contacts have been available for some time and 'Doghouse' Mounts value and convenience has become well estab- their In the original equipment, the "doghouse" bracket lished. Recently, complete assortments of exact length is staked to a control with an unthreaded bushing and single shafts have been made available by several manu- the 4 -legs of the bracket and the PC terminals on the facturers. The range of sizes and types is such that control are mounted and soldered into holes in the technicians should no longer have to cut a shaft to find board. Even though the 4 -leg bracket has spring -type one to fit a specific application. The range in size of clips, these legs are usually soldered. one typical 1/a in. metal shaft is shown in Fig. 3. To replace, use a replacement bracket available Insulated Plastic Shafts from major line distributors. Assemble the bracket A "non -switch" type control (Fig. 4) employs to the proper bushing type control, equipped with either insulated plastic shafts which are essential in "hot- wirewrap or PC terminals, and use a mounting nut to chassis" sets. (Please note that all sets of this type have a hold the bracket in place. If a control with wirewrap nominal electrical and mechanical rotation of 300 deg.) terminals is used, bend the terminals to conform to There's a fairly comprehensive selection of these original terminal configuration. Mount the control controls available to technicians from several manu- terminals and 4 -legs into their respective holes in the facturers. With their increasing use in original equip- PC board and solder control terminals and also the ment, however, there is an increasing likelihood that 4 -legs of bracket, (only if all legs were originally sol- situations will be encountered where a replacement of dered). If the original control has an OFF/ ON switch, the proper value and taper is not available. In these replace it with a conventional solder lug terminal cases, replacement can be made by using the bushing switch, even though the original may have had PC ter- mount type and merely adding a special adapter plate minals. Then run wire leads from the switch lugs to the onto the bushing. The required metal or insulated proper points on the PC board and solder. replacement shaft is then plugged in, as shown in Fig. 5. Frequently, removal of the bracket and control In many cases, chassis are punched with a hole from the PC board, without damage to the wiring rib -

63 MAY 1965 Fig. 4 - Non -switch type control with plastic shaft.

facing in the opposite direction from the shaft (towards the ears). To adapt conventional bushing mounting controls to this type, an adapter plate is available which snaps on to the rear of the standard line of wirewrap terminal controls. (See Fig. 7.) Then a shaft is plugged in at the bushing end which becomes the normal operating end. After removal of the original control, simply bend the wirewrap terminals of the replacement to conform to original control terminal spacing and plug in a re- placement insulated shaft to duplicate the original. Dual Concentrics A complete line of the off-the -shelf exact duplicate concentric shaft dual control replacements are avail- able for almost every requirement. bon, can present a few problems on occasion. A comprehensive variety of exact length inner and From my experience, the safest and most expedient outer shafts is complemented by inner and outer shafts procedure is as follows: 1) Use a tin snips to cut off of the Universal type which can be cut off as required. the 4 -legs of the bracket adjacent to the PC board, Exact length inner shafts for SPST push-pull 2) cut off the control terminals in similar manner using switches are available to meet the demands for these diagonal cutters, and 3) unsolder each individual popular replacements. Incidentally, there is no major bracket leg and terminal quickly, one at a time and replacement source for the push -push type switch for remove. "plug-in" shafts. A few limited types are available, but these are Reverse Mounting Controls not readily obtainable since the push-pull switch will serve equally as well as the push -push type This type of mounting has become quite popular in roughly 99 percent of the applications. As a result, in TV sets the past year or two. These controls have the push -push type is not manufactured or stocked "ears" at in the opposite end from the shaft. Usually the broad range of shaft lengths available in the push- they incorporate PC terminals parallel with shaft but pull type.

Fig. 7-Adapter plate is snapped to Fig. 5-Bushing-mount control with adapter end of bushing mounting control for reverse plate and shaft. Fig. 6-'Doghouse' bracket. mounting to PC board.

/

64 ELECTRONIC TECHNICIAN "I haven't the space for a large inventory...

that's why I always specify Greyhound Package Express !" on Your inventory can be as big as the catalog from which shipments travel aboard regular Greyhound buses you order, when you specify Greyhound Package Ex- fast, frequent schedules. What's more, Greyhound a press. Using this fast, efficient, low cost shipping serv- Package Express works 365 days a year, 24 hours Col- ice, you can order only what your customers need. day, weekends and holidays. Convenient C.O.D., And have it when they need it ... usually the next lect, Prepaid or special charge account service, too. morning. Very often, the same day. No premium rates For information on service, rates and routes, call to pay, either! You'll save space, time and money, Greyhound, or write today: Greyhound Package without sacrificing the needs of a single customer. Your Express, Dept. 53-E 140 S. Dearborn Sr., Chicago 3,111. It's there in hours...and costs you less

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. . . for more details circle 32 on postcard 65 MAY 1965 while Saturday children's program- TV homes. At that time, NBC's ing had aver- a 90 percent edge. NBC's To- age rating in black and white homes night Show scored an advantage COLORFAX of 89 (50 million) could be a 19, as com- percent in color homes. pared with a 34 in color homes. The study financed by all three net- This would give NBC a 1.4 rating ARB Color TV Study works, also notes that NBC wins ev- point advantage over its rivals, and The results of a survey of color ery half-hour in which it offers color TV viewing for every million color TV sets sold, habits conducted by programing, and in the 3 million col- American NBC should gain 0.3 of a rating point. Research Bureau show that or homes 14 out of the top 15 shows prime nighttime The matter of whether or not the color shows draw 80 are NBC color properties. The only novelty percent more viewers of color TV wears off was in homes with black and white show on the list is also taken color sets than in homes into consideration in the with B/W. Bewitched, ranked number 15. ARB survey, A survey of six NBC daytime and the answer was shows Translating the study in terms of "no." The average revealed a 62 percent ratings advan- rating of NBC color growth, it was pointed out that nighttime color programing tage in homes with color receivers, next year is 39. The there will be 5 million color average rating among recent purchas- ers of color sets (one to seven months) was slightly higher at 44. For those who owned their sets from eight to 19 months, the rating was 40, while the rating for color veterans (20 months -plus) was 37. NBC's nearest competitor in color programing is ABC, which offers ap- proximately seven nighttime half- hours a week as compared with NBC's 39. Study showed ABC's own color homes advantage was only 9 percent.

Color TV Production in Japan Our west coast sources disclosed that Japanese manufacturers have produced around 60,000 color TV sets during 1964, as compared to only 4000 in 1963. The report said that a sizable increase in 1965 production is expected with over 80,000 units a forseeable figure.

Philco Ad Campaign SOUND Philco Corp. is embarking on a col- or television advertising program ON THE MOVE! which calls for 41 four-color, full page magazine ads and a newspaper AMPLI -VOX campaign that will support color and B/W TV, and stereo high fidelity. "We believe the TV market will be half color and half monochrome by SOUND 1970," said Charles CRUISER S. Grill, director COMPLETE MOBILE SOUND SYSTEM of advertising of the Consumer Prod- ucts Div., "with dollar volume favor- Equip any car, truck, bus, or boat for clear powerful ing color substantially before 1970. soundcasting in just 45 seconds "We will be heavy in national maga- 32 watt solid state amplifier plugs into auto cigarette zines that provide good lighter socket coverage of the adult population. National adver- Noise cancelling hand-held microphone has 5' coil cord, push -to -talk switch tising dollars allocated for local use Two weatherproof horn speakers swivel and lock will be programed in support of spe- in any direction, are pre -mounted on car -top carrier cific merchandising promotions." ready to clamp to car Philco will run a total of 41 four- Ideal for voice or music; inputs for tape recorder, color, full page ads turntable, etc. in these magazines: LIFE, SATURDAY EVENING POST, LOOK, READER'S DIGEST and TV GUIDE. Model S-310, Complete system, including F.E.T. $16 9.9 5 "Our advertising dollars will be Model S-300, Amplifier only, including F.E.T. $79.95 concentrated on targets that research has identified Write for literature and detailed specifications. as prime color TV cus- tomers," Mr. Grill said. "We deter- AMPLI -VOX AUDIO PRODUCTS are manufactured in U.S.A. by mined the age and income charac- teristics of families that buy color tele- PERMA-POWER COMPANY 5740 N. Tripp Ave., Chicago, III. 60646 vision and selected media that reaches Phone (312) 539-7171 these families most effectively." ... for more details circle 51 on postcard 66 ELECTRONIC TECHNICIAN NO ONE CAN GUARANTEE YOUR FUTURE

NOT EVEN YOU!

WE KNOW 156 MEN WHO DID THE NEXT BEST THING They Became a Part of the Lafayette Associate Store Program 156 Business can be a funny proposition. You're an independent businessman, like those other men. Then one day you discover competition has become too big and too tough to take on by yourself. You want to fight back-launch new advertising campaigns, expand your line, send out sales literature, mail out catalogs, do something to keep the business going. But it's just too much for one man alone. You need the know-how and support of a large corporation ... the advantages you get as a fran- chised dealer in the Lafayette Radio Electronics Associate Store Program. This program enables you to own your own store in America's fastest growing chain of retail electronics centers. You en- joy every benefit of this 44 -year -old organization, while you maintain your financial independence through ownership. the If you have a basic knowledge of radio, TV or electronics, you owe it to yourself to investigate Lafayette Associate Store Program.

This Is What We Offer You: 4, Protected Territory - Yours will be complete Lafayette has for 1. Business Stability - the only franchised Lafayette Radio Mail the coupon obligation. been in business 44 years. You'll Electronics Associate Store in your Without cash in on this established reputa- marketing area. information tion.

5, Marketing Guidance We'll help Product Diversification You can - - - 2. - you set up a complete operation to Radio Electronics Corporation sell everything Lafayette offers .. . Lafayette build a successful future, and main- Dept. ASETE-5 re- hi-fi stereo, citizens band, tape be 111 Jericho Turnpike tain it. We will always available Syosset, L. l., N. Y. 11791 corders, radios, tools, and much way to help you in any possible. Mr. Robert Laub: more. You'll attract more customers I can Please send me full information on how than you ever thought possible. We are looking for a limited num- own my own profitable business. I understand obligation. ber of men who want to become a there is no 3.Advertising Support - Year 'round Lafayette Associate part of the Name advertising, publicity, public rela- Store Program . . . . men who tions and promotional campaigns are willing to invest $10,000 to Address have established Lafayette and its to make a new business franchised dealers as America's Hi- $30,000 themselves. City State Zip Fi and Electronics Centers. career for lam MINIMMIMIMIIIMIIMIIMIIMIIMM circle 41 on postcard .. . for more details 67 MAY 1965 FIRST ALL-CHANNEL UHF ANTENNA BUILT

MORE GAIN than Any Parabolic Antenna

MORE GAIN than Any Log Periodic Antenna

MORE GAIN than Any Ordinary 16 Element Yagi Antenna

Need Even More Power? Stacking Planar-Grid Yagis increases gain 41 %for sharp Want to Couple VHF, pictures even in deep fringe.

Every antenna comes 1 with UHF and FM? stacking bar in the box. Super -efficient VHF -FM coupler is ' built right in .... ' you work with just

1 down lead! For perfect UHF and VHF reception. Couple a Planar -Grid Yagi Model No. U-990 with the Winegard Colortron .. . GOLD VINYLIZED it's easy with Planar -Grid's built- Only $29.95 list in coupler. Couples to any VHF PATENT PENDING antenna.

Pull in more UHF stations! Use the Winegard UHF -212 antenna Model No. amplifier ... Only $44.95 list. U-980 Model No. U-970 Model No. U-960 Only $19.95 list Only $11.95 list Only $7.95 list

68 ELECTRONIC TECHNICIAN FOR THE CRITICAL DEMANDS Of COLOR TV Iine92nd Planar -Grid FULL WAVE YAGIS

Unquestionably the Most Powerful All Channel UHF Antennas Ever Made!

First Antenna Ever Designed Using the LOG PERIODIC AND "V" TYPE Full Wave Planar -Grid Principle ANTENNAS, regardless of large size and total number of connected elements, First Antenna With Progressive Gain have no more than two or three of their Accumulation Across the Entire UHF elements working on any one channel. Band from 14 to 83 This puts a low ceiling on the available Planar -Grid UHF antennas have arrived gain for these types of antennas although An- . a most significant advancement in they do have adequate bandwidth. UHF antenna design. These new UHF other disadvantage is the multiple lobe antennas have the power and critical patterns, especially those antennas em- characteristics necessary for consistently ploying "V'd" elements working on the perfect color reception. And of course, third and fifth harmonic mode. This the TV antennas that are best for color type antenna is unable to reject inter- are best for black and white, too. fering signals from the side because of Here's how the new Planar -Grid Yagis these side lobes and can easily degrade eliminate the disadvantages of all exist- picture quality -especially in color. ing UHF antennas! Examples: PLANAR -GRID YAGIS, in comparison, THE 4 -BAY BOW -TIE - and Collinear have the sharp uni -directional charac- antennas lack bandwidth. They require teristics to insure clean, sharp pictures at least two separate antennas tuned to and perfect color. On the Planar -Grid opposite ends of the band to give good Yagi, all parts of the antenna work to- gain across the entire UHF band. In- gether on every channel (Progressive creasing the gain by stacking of a 4 -Bay Gain Accumulation Principle) giving it Bow -Tie is equally impractical because the highest gain and greatest bandwidth it further reduces bandwidth which is of any UHF antenna for a given size. already inadequate. With Winegard's high- Highest Gain, Complete Bandwidth, new Planar-Grid Yagis, you get the Precision 300 ohm Impedance Match est gain UHF antenna on the market across the entire UHF band and Pin- PLUS complete bandwidth. point Directivity-are characteristic of ORDINARY HALF -WAVE UHF YAGIS, the brand new Planar -Grid Yagis from while having high gain, are frequency Winegard . these are really color - sensitive and normally maintain top gain quality UHF antennas. over only six or so channels. Winegard CONSTRUCTION, TOO... © Winegard Co. -1965 Planar -Grid Yagis are made a full wave WINEGARD They Features include Winegard's exclusive wide to double the capture area. wrap -around mast clamp, complete fac- give very high gain over all 70 channels. tory preassembly and our new Gold PARABOLIC ANTENNAS, by increas- Vinylized finish to protect against ing size, can theoretically increase gain, weather wear. the but a parabolic type comparable to the era of now with the color - U-990 Planar -Grid Yagi would require Enter UHF 10 Para- quality UHF antennas-Winegard an antenna of at least ft. in dia. Planar-Grid Yagis! Ask your distributor bolics are inefficient and impractical be- for spec sheets today. cause of size, cost, high wind resistance. or write CORNER REFLECTOR ANTENNAS are medium gain antennas and, unlike most basic antenna designs, an increase in Winegard Co. Model No. U-950 the size does not appreciably increase ANTENNA SYSTEMS Only $5.95 list gain. The gain of the Planar -Grid Yagis is directly proportional to size. 3019F Kirkwood Burlington, Iowa ... for more details circle 70 on postcard 69 MAY 1965 TOUGH DOG CORNER

Difficult Service Jobs Described by Readers

Worn to a Frazzle knowing that it was bad (because it turned back. This would go on until I received a call from a new cus- had no folded dipole, lead-in con- the AGC control was finally all the tomer who said "the picture is not tinuity could not be checked at the way to minimum. Then the picture clear." I asked the owner to switch the set end). So then I went out the went into complete overload. set on and leave it on until I arrived. apartment window, to the fire escape Tubes were changed from the 6J6 When I arrived, a glance at the screen and started checking the lead-in, inch on back. It was not being caused by a showed a weak, "snowy" picture. by inch, up the wall. At the top floor, tube in this area. I then brought the Most channels looked the same - just below the flat tar -paper roof level, set to the shop. except some were worse than others. a cement ledge about 6 inches thick It took only a few minutes for me I switched the set off and checked the protruded from the brick wall out- to come to the foreboding conclusion lead-in connections to the set and the ward about 4 inches. The lead-in rest- that this was going to be another one leads from the set to the tuner input. ed flat against it-with no standoff to of those "you-know-whats." But it was I then changed the tuner RF and hold it away from the ledge. I grasped obvious what was happening - partly oscillator tubes. But this did not help. the lead-in at this point to examine it obvious, that is. As the set warmed I substituted another RF tube. No -and it parted! I found mystelf hold- up, the video signal at the detector improvement was noted. Since I ing the piece that was attached to the output gradually increased until it didn't have a "rabbit -ears" with me, set while the short 20 ft piece attached tripled it's amplitude. This heavy de- I reasoned that it was either a break- to the antenna dangled in the air! tector output, directly coupled to the down in the tuner or a bad antenna. It was obvious what had happened video amplifier grid, gradually de- I checked the lead-in from the set to by observing the end of the lead-in I creased the 6AG7 current flow and in- the window and went to the roof and held in my hand. Over a long period creased the tube's plate voltage. This inspected the antenna-a conical. It of time the rough cement had cut rising voltage, directly coupled to the appeared in good condition. And the through the poly and right through the sync separator grid, caused current lead-in, down the side of the apart- copper strands as the lead-in waved flow to increase in this tube. Because ment -house wall, also looked good. I back and forth in the wind. The only of this increase, the separator tube's noticed, however, that it had only one thing holding it together, finally, was cathode voltage also rose. Since the stand-off insulator at the roof top and a thin flat strip of polyethylene which AGC amplifier's grid voltage was one at the third floor where it entered parted altogether when I grasped it. supplied by a divider in the separator's the apartment window. It waved slow- I spliced in a foot of good lead-in, cathode circuit, it too was rising while ly back and forth a few inches in the taped a one -inch -diameter "roller" to all this was going on. Naturally, once breeze. the splice where it crossed the ledge the grid voltage on the amplifier tube I went back down stairs and asked (to keep the lead-in from rubbing was upset, the whole AGC system the owner one question. against the cement) and the job was went berserk. This further contributed "When did the trouble begin?" done. I collected $7.50 for an hour's to the cycle by increasing IF gain. "About two weeks ago," I was told. work, $3 for a service call, and the But where was it all beginning? A I was also informed that the picture customer was very happy. They sent slight variation in any one of these had been "flashing and jumping" for me a number of good customers later. interrelated stages could have started some time before the condition de- -Jim Warner, New York City. the ball rolling. After fruitless search- veloped. The owner also confessed ing I realized that I was getting no- that three other TV men had looked where fast. All the old tricks failed at the set during a period of weeks. and so did some new ones. While Two technicians said the set had to Where Does a Circle Begin? checking around the 12AU7 detector go to the shop for a checkup. The The 1951-1952 RCA TV AGC sys- tube, I noticed that, although the grid other one said it was a breakdown in tems have always been tricky. So and cathode of this tube acted as the the set or the antenna was bad. In any many stages are independent that detector diode, the plate of the same event, the owner was reluctant to do overloading or other seemingly obvi- triode section was tied into the 6BQ6 anything except call the fourth tech- ous AGC problems make it difficult grid through a 2.2 Ma resistor. I nician-which happened to be me. I to know where to begin. I've worked checked voltage on both sides of this was not thinking along the same lines on many of these sets and thought resistor and discovered to my amaze- as the third technician. that I knew them inside -out until I ment that the 6BQ6 grid read zero! I But one thought still bothered me, tangled with a KCS72 recently. put in a new 6BQ6 and the set worked especially since the set had shown the When this set was first switched on perfectly. I was delighted but com- "flashing and jumping" symptoms it had a perfect picture. As it warmed pletely flabbergasted. prior to developing snow. It could be up the picture would slowly darken I put back the old tube and reviewed trouble in the antenna system. But and begin to pull. But when the AGC the situation again. But I still can't still . . . an intermittent capacitor control was turned back a bit the pic- figure out why the sides of the pic- could have finally broken down in the ture snapped back straight again. It ture didn't shrink - not even a six- tuner. I did not want to take the would stay good for a while and then teenth of an inch. - Frank Salerno, antenna down without definitely overload. Again the control was N.Y.C.

70 ELECTRONIC TECHNICIAN multiple socket SPEED plus Gm*ACCURAC y CREATES MORE

Basic for the professional service shop PROFIT

ell more tubes per customer gave call-backs I atisfy more customers I

*Makes test under B & K MODEL 700 DYNA-QUIK actual set -operating DYNAMIC MUTUAL CONDUCTANCE TUBE TESTER conditions with obsolescence protection

Everyday use by thousands of professional servicemen has proved its TESTS All TV and Radio Tubes, speed ... its accuracy ... its efficiency. Old and New can quickly check all the tubes in the set, detect hard -to -locate You Novars weak tubes that need replacement ... and sell more tubes. Provides TESTS Nuvistors and multiple-socket section to quick -check most of the TV and radio tube types the true dynamic mutual conductance way*-plus simplified TESTS 10 -Pin Tubes switch section to check new tube types in Dyna-Quik emission circuit. Also includes provision for future new sockets. TESTS 12 -Pin Compactrons Makes test under set -operating conditions. Checks each section of multi - for all shorts, grid emission, leakage, section tubes separately. Checks TESTS European Hi-Fi Tubes, and gas. Makes quick "life" test. Exclusive adjustable grid emission Voltage Regulators, and Most test provides sensitivity to over 100 megohms. Insures your reputation. Industrial Types Quickly pays for itself. Net, $17995

See your B & K Distributor or Write for Catalog AP 21-T

NEW TUBE INFORMATION SERVICE B & K MANUFACTURING CO. Keep your tube tester up-to-date. DIVISION OF DYNASCAN CORPORATION Subscribe now to tube information service, available every 3 months. 1801 W. BELLE PLAINE AVE. CH ICAGO, ILL. 80813 Canada: Atlas Radio Corp., 50 Wingold, Toronto 19, Ont. Export: Empire Exporters, 123 Grand St., New York 13, U.S.A. ... for more details circle 17 on postcard 71 MAY 1965 NEW PRODUCTS

Actuator 200 100 mr/hour is exceeded. Weighing Aerosol Spray 203 An actuator for electric counters is 5 oz, the unit detects and measures An insulating spray for protecting announced. The ES4 switch can op- radiation with a halogen -quenched high voltage components such as fly- erate counters, signaling devices, pi- Geiger -Mueller tube. Gelman. back transformers, yokes, etc. has been introduced. "NO ARC" is used for electronic applications in high volt- Splicer 202 This splice gun will splice cable sizes 16 to 30 in an automatic opera- tion. The two conductors to be joined

lot circuits, folding machines and tow- el mangles. It has a rated speed of 300 counts per minute. ITT.

Radiation Detector 201 Radiation warning at a preset alarm level is given by this pocket radiation rate monitor. You can set this pocket-

age circuits, microwave tubes, trans- mitting tubes, for static voltage gen- eration, masking pointed or sharp hi - voltage sheets' metal corners and for electrical applications in motor, gen- are inserted into the jaws of the gun erator, and transformer windings, and without twisting and stripping the in- overcoating non -active parts of sulation beforehand. Operation of one switches, contacts and terminal strips, trigger actuates an electric motor and for coating automotive and other which twists the conductors together wires where maximum insulation is for a set number of turns. Operation required. Chemtronics. of a second trigger applies battery po- tential to the twisted conductors which burns off the insulation, cuts off sur- Capacitors 204 size beta -gamma detector to buzz plus conductor and welds the two con- A line of encapsulated capacitors is when an alarm level of 3, 10, 30, or ductor ends together. Jonard. announced. The capacitors are de- signed for test and measurement, TWO OF A KIND yob ENGINEERED for Today's Requirements CONTACT CLEANERS New Super SAFE FOR PLASTICS New Super HUSH metals, elastomers and EVER -QUIET Selected nonflammable virtually non- Selected Solvent* toxic. With excellent di- Solvent* and 100% electric properties to the Lubricant Silicone Oils flow of electric current. Quality at 8 oz. & 16 oz. Low Price * No Carbon Tet Spray Can 6 oz. Spray Can control, communications and consum- WRITE FOR LITERATURE er products applications and are ini- CHEMICAL ELECTRONIC ENGINEERING, INC. tially available in two case sizes with MATAWAN, NEW JERSEY ratings from .001 to 1.0 µf and from 100 to 600 vdc at 85 deg C. GE. ... for more details circle 24 on postcard 72 ELECTRONIC TECHNICIAN convergence and color adjustments are easier, faster, more accurate!

B&I{ MODEL 1240 LOW PRICED PORTABLE CO OR GENERATOR with crystal -controlled keyed rainbow color display!

Thinnest Horizontal Lines! Smallest Visible Dots! (Just one raster scanning line thick) only Simplifies In -Home (or Shop) Color TV Set -Up and Servicing $13492T You're the color TV expert when you use the "1240." dots are just one raster scanning line thick. Lines begin advantage of B&K quality-with features off -screen and end off -screen, with no break in line. You have the accessible not available before at such surprisingly low cost. Dot brightness is adjustable with easily control. Chroma Level Control simplifies color sync Provides crystal -controlled keyed rainbow color dis- trouble -shooting. play on TV screen to test color sync circuits, range of hue Operates on channels 3, 4, and 5, and adjustable with- control, and align color demodulators. Shows ability of out removing cabinet. No connection inside TV set is TV receiver to display color values. needed. Power transformer operated and line isolated to Provides dot pattern, crosshatch, horizontal and ver- prevent shock hazards. Operates reliably on 105-125 tical lines. Highly stable crystal -controlled count circuit VAC, 60 cps. (Color Gun Killer is available as optional with small -step count assures greater reliability and sta- accessory.) Extreme lightness and portability (9 lbs.) bility of color, dots, and lines. All horizontal lines and make it ideal for in -home servicing.

CO See it at your B&K Distributor B & K MANUFACTURING CORPORATION or Write for Bulletin AP2I-T DIVISION OF DYNASCAN 1801W. BELLE PLAINE AVE.. CHICAGO, ILL. 60613 Canada: Atlas Radio Corp., 50 Wingold, Toronto 19, Ont. Export: Empire Exporters, 123 Grand St., New York 13, U.S.A. ... for more details circle 18 on postcard 73 MAY 1965 NEW PRODUCTS

Oscilloscope 205 A miniature monitor oscilloscope measuring 7 x 5 x 3 in. is introduced. Utilizing a two in. CRT, the scope

has application in the CB and ama- teur radio applications. Control Prod- ucts.

Whatever your replacement need ... Inverter 206 An inverter which operates from 12 vdc and delivers 110 vac 60 cps at 140 w maximum is announced. The

CALL FOR AEROVOX CAPACITORS

Whatever the requirement, there is an Aerovox capacitor to sat- inverter is used for operating most isfy it. Your Aerovox distributor can supply your every need with 11 in. to 13 in. portable TV sets in automobiles, boats, mobile homes, a complete line in of -stock capacitors that are designed and buses, trucks, trains and planes. ATR. manufactured to meet the highest possible reliability standards.

And when we say "A COMPLETE LINE" we include: Portable TV 207 An eight lb portable television set ELECTROLYTIC CAPACITORS CERAMIC CAPACITORS with a built-in UHF tuner is intro- Twist -Prong Cans High Voltage duced. The TV operates on regular Tubular Temperature Compensating Miniatures General Purpose Discs Wax Filled Tubulars

BYPASS CAPACITORS MICA CAPACITORS Radial & Axial Leads Molded Dual Dielectric Axial Lead Straight Mylar Dipped Radial Lead

R Your local Aerovox distributor offers sure, one -stop service for all capacitor replacement. Buy the best-buy Aerovox. house current (ac), snap -on battery, 12 y auto or boat battery. The unit EROVOX has automatic gain control circuitry, AEROVOX CORPORATION aluminized 5 -inch tube, telescope an- g DISTRIBUTOR DIVISION NEW BEDFORD, MASS. tenna for both VHF and UHF, and 28 transistors. Size is 83/s, 41/4 and Technical Leadership - Manufacturing Excellence 6% in. Sony. ... for more details circle IO on postcard 74 ELECTRONIC TECHNICIAN MORE SALES! IT'S AS SIMPLE AS THAT! And with ANTENNACRAFT Antennas Reception is at its very BEST. a little effort goes Just a little extra care and extra FOR CHANNELS 2 TO 83 into Antennacraft - and it shows - in the appear- ance of the product and in the sharp, clear pictures UHF - VHF - FM on your customer's television set.

The new UHF -VHF TV sets need a combination UHF - VHF antenna to take advantage of the total pro- ONLY graming available. Antennacraft's Channel -Span- t24.95 ners are all channel antennas, VHF 2 to 13 and UHF be used with these Ilefs173eA sc:s3reix 14 to 83 and are designed to 1lj1i\J14S1 .13:1911M3:* new sets with only one lead-in.

Antennacraft's Channel -Spanners produce snow -free, ghost -free pictures to the far edge of the UHF class ONLY 117.95 B signal area. Maximum signal response is obtained from VHF and FM stations together with good pic- ture quality at the class B distance and throughout the medium fringe areas. RErIER !WILT FOR REIER pEREORAAN(

If you are not already using Antennacraft products, contact your distributor for full information on all / AuromoiK Channel Sel et tor Antennacraft products. Find out for yourself TV ANTENNSS fine DUN LINGTON. IOWA how that "little extra" pays off in bigger profits for `'INIsmosgov you.

... for more details circle 12 on postcard 75 MAY 1965 NEW PRODUCTS Holding Fixture 209 A fixture designed to hold chassis, rectangular objects, and irregular ob- EFFICIENT! jects, up to 500 lbs is introduced. The SAFE! -170 -172 AND -125 ETV Antenna 208 NEW CLAMPS ARE FAST! DISK BRAKES HOLD INTERCHANGEABLE A two foot parabolic receiving an- HIGH TORQUE LOADS tenna covering the frequencies be- tween 2500 and 2690 megacycles is

ADJUSTABLE AUTOMATIC FROM 30 t0 36 STAP LE GUNS For Fastening Any

STANDARD 30" BEAM Inside or Outside ADJUSTABLE FROM 10" TO 30 Wire ` EXTENSION KIT Up to 1/2" in Diameter - l - ADJUSTABLE FROM 22 ` 30" TO 96 TO Telephone wire Intercom wire / nUPl'/ß' fixture is available with three differ- No. T-18 Bell wire Thermostat wire ent types of clamps: a universal chas- nUP TO 1/4rr Radiant heating wire sis clamp that fits all standard Hi-Fi, Radio & TV wires introduced. This is the band recently RETMA type panels; a scissors clamp No. T-25 Tapered striking edge assigned to Educational Television use. for straight sided items; and a 2 x gets into close corners! Gain of the antenna is a minimum 21 121/2 in. slotted mounting UP TO Available in: plate for n 1/2,, Brown, Ivory, Beige, db relative to a linear isotropic radi- holding custom parts. According to No. T-75 Mane!, Bronze, Natural ator, the manufacturer claims. The the manufacturer, the fixture is fully antenna may be positioned for either equipped with disc brakes to lock 3211:1=12:1332:4 vertical or for horizontal polarization. high torque loads. Sandefur Engineer- 1 JUNIUS STREET BROOKLYN 12, N. Y. Tace. ing. for more details circle 15 on postcard Recommend and Install Turner CB Microphones Your reputation is based on quality of workman- THE TURNER 333 ship, true, but equally important is the quality of A noise -canceling mobile microphone for CB, ama- materials you use. That's why, when it comes to teur and 2 -way radio. It's microphones, you can always feel confident with the only professional com- munications microphone for many years Tuner - the industry leader. now available for CB. Re- Tuner microphones don't let your customers sponse: 300-3000 cps - (Voice - frequencies). List or your reputation - down. price, $21.50. THE TURNER 454X Outstanding single-sideband base sta THE TURNER 355C tion microphone. Response: 300-3000 cps. List price, $26.50. The popular original equip- For more fine Turner microphones, send ment CB mobile micro- today for the Turner catalog.

phone with exclusive grip - to -talk switch. Response: THE TURNER MICROPHONE COMPANY 80-7000 cps. List price, 918 17th Street N.E. $12.50. Cedar Rapids, Iowa

In Canada: Tri -Tel Associates, Ltd., 81 Sheppard Ave., West, Willowdale, Ontario Export: Ad Auriema, Inc., 85,Broad Street, New York 4, N.Y.

.. . for more details circle 66 on postcard 6 ELECTRONIC TECHNICIAN ALL NEW FROM itarefrroZ

OBSOLESCENCE

PROTECTION Realistic, Practical No Compromise!

MORE PROFIT Sell Because You'll MULTI -SOCKET More Tubes. Them SPEED... Sell Honestly! No Compromise In Accuracy! MODEL 799

519995

From the laboratories of the world's leading tube any possible new tube types. tester manufacturer comes the model 799 "Mustang" A solid-state power supply gives increased accuracy -a completely new tube tester. and dependability. An all -transistorized gas and leak- for Multi -socket tube testers used to have two serious age test circuit sets a new standard of rel ability that can "chew up" drawbacks: circuit limitations made them obsolete spotting "tricky" tube defects profit. You can actually read interelement leakage overnight and, at best, no more than 10% of their your to 50 megohms; gas grid leakage effects to 0.1 µa! tests were actually mutual conductance. But the Hickok "Mustang" doesn't compromise; it delivers We call it the "Mustang" because it uses fresh, new and because it gives you a real honest mutual conductance tests. And a unique cir- engineering ideas new profits. cuit approach, together with an easily replaceable opportunity to break into accessory socket panel, makes it "circuit ready" for See it at your Hickok distributor or write for circular TT799.

THE HICKOK ELECTRICAL INSTRUMENT CO. 10566 Dupont Avenue, Cleveland, Ohio 44108 Represented in Canada by Stark Electronics, Ajax, Ontario Internationally by Hughes International, Culver City, California ..:..RIr ... for more details circle 36 on postcard MAY 1965 77 Our CB story this month Color TV Crystals 211 NEW PRODUCTS A line of TV color control crys- is short and sweet: tals is announced. They are des- ignated #CTV358 and are supplied in a hermetically sealed case with two- Reversible Drill 210 inch leads. The crystals are for use in An industrially -rated, t/2 in., four - the color burst circuitry of modern speed drill is introduced. Double re- color TV receivers. Semitron. duction gears and electronic speed con-

Tube Kit 212 A package offering an assortment of the 17 most popular color receiv- the ing tube types is introduced. Tube types included are: 1V2, 3A3/3B2, beauty of this baby is its trol are combined to provide four speeds of 630, 730, 2200, and 2400 rpm with no load. Speed changes are 3AT2, 6AW8A, 6BK4A, 6DQ5, 18" length! made with a gear shift control locat- 6GF7, 6DW4, 6EA8, 6EW6, 6GH8A, ed on the back of the handle. It meas- 6GM6, 6GU7, 6GY6, 6HF5, 6JE6 ures 11 x 81/2 x 31/2 in. Weight without and 12BY7A. The kit of tubes is cord is 61/2 lbs. Three-wire cord is 6 packed in a fiberglass thermo-insulated ft long. Wen. utility bag. RCA. M-130 'Mighty Mite" Columbia Wire's Permaline 18" Mobile CB antenna television transmission cable costs a few cents more, but Capacity -matched to car body it's well worth it. Permaline is the only television wire available for excellent VSWR of such quality that it can Fine-tuning adjustment be guaranteed, in writing, for 15 and 25 years. Professional -type, 21/" stain- Columbia Wire is proud to say in ten years we have never less steel shock spring that had to replace as much as one foot of Permaline for reasons of deterioration. M-130 Columbia Permaline has electrical characteristics similar "Mighty Mite" to those of ordinary brown 3A" snap -in mount- polyethylene lines but the no soldering difference is, a small amount of carbon black that is added M-131 to a virgin compound to protect the transmission line from "Maggie Mite" ultraviolet rays of sunlight. Gutter clip mount- Install Permaline and you will hang it anywhere be assured of a happy customer and repeat business ... but not for a new television cable. Permaline is Available From the Your Local Distributor. antenna Write for samples and literature. specialists co.

12435 Euclid Ave., Cleveland, Ohio 44106 A division of A/S Industries, Inc. Export Div.: "stripes of quality" 2850 Irving Park Road 64-14 Woodside Ave., Woodside 77, N.Y.

... for more details circle I I on postcard . for more details circle 26 on postcard 78 ELECTRONIC TECHNICIAN Introducing a Complete Line of Litteliuse Quality Circuit Breakers

ME 1111111111111111LAI

Actual Size 134 X 1Y16 X 1/2"

Exact replacement from factory to you

Designed for the protection of television receiver circuits, the Littelfuse Manual Reset Circuit Breaker is also ideally suited as a current overload protector for model railroads and power operated toy transformers, hair dryers, small household appliances, home workshop power tools, office machines, small fractional horsepower motors and all types of electronic or electrical control wiring.

I11 11 E F U DES PLAINES, ILLINOIS

... for more details circle 43 on postcard .1( NEW PRODUCTS

Tool Stands A line of steel tool stands is an- THE//7/a/ nounced. Tool stand sizes are either 20 in. wide by 28 in. deep or 24 in. OF 21ö7dUl°' Le2 TV ANTENNAS What Can Make ADVANCED ENGINEERING an MATV Installation DESIGN Easier, Cheaper, BEST FOR COLOR AND BLACK AND WHITE and Better?

wide by 36 in. deep. Both are 34 in. high on floor glides or 361/2 in. high on casters. Penco.

Only Colormagic... Tape Recorder has been top -rated in independent con- A camera sized standard speed tape sumer publications for broadband per- recorder is introduced. It operates at formance, gain, front/back ratio, beam width, impedance match, construction A and ease of assembly, etc. System Designed Only Colormagic... has FHR which is the exclusive deve- and Equipped lopment of GC Electronics for process applied to all Colormagic series of an- tennas, to provide a resonating action by VIKING! within the elements of the fundamental harmonics of both the high and low bands. Every piece of MATV equipment has been designed Only Colormagic... to save the technician valuable time and has the outstanding Award Winning Car- money. Each ton in which all Colormagic series an- component is manu- tennas are carefully packed. a speed of 1%8 ips, weighs two lbs factured and tested under rigid and uses four "C" size flashlight bat- quality control methods so that «. teries. Price $39.50. Concord. they match perfectly from the an- tenna to the set. When it comes to laying out the Only Colormagic... Pocket Voltmeter A pocket-size MATV system you can't beat has the endorsement voltmeter is an- nounced. The Viking's "know-how" and ex- from Philco, one of the RECOMMENDED 6v model number VT -101 leading manufacturers can be used to check TV, radio and perience. Best of all, it doesn't of TV receiving equip- PHILCO other electrical appliances. It meas- cost a cent to consult with us. Im- ment. Colormagic an- ures 65 to 800 v, ac or dc. mediate and courteous attention tennas a re recommend- COLOR & Net price BLACK.. WHITE $1.49. IEH. will be given to any problem. ed and approved for all TV INSTALLATION Philco TV Color and Write or call COLLECT. black and white install- ations. Guard Rail Cart Write now for free four page A guard rail cart color brochure made of stainless which describes steel is designed to carry and store GC instruments, Manufacturers of Quality Coaxial Cables ELECTRONICS the entire Color - supplies and equipment magic series of that must be wheeled from area to and Television System Products <22: antennas. area for use. Specifications of the 830 Monroe Street, Hoboken, N.J. Dept.: BMW Model #316 include: shelf size, 151/2 Call Collect: N. Y.: (212) WH 3-5793, G C x 24 in.; number of shelves, three; ELECTRONICS over-all size, Hoboken: (201) OL 6-2020 400 South Wyman Street Rockford, Illinois 165/s x 27% x 331/4 for more details circle 67 on postcard for more details circle 31 on postcard ... 80 . ELECTRONIC TECHNICIAN Portable Stereo 220 Transistor Tester 221 A portable stereo phonograph is A transistor tester which tests tran- announced. It can play any size or sistors in or out of circuits is an- speed of record and a 45 rpm adapt-

in.; shipping weight, 30 lbs; capa- city, 200 lbs. Lakeside Mfg. or spindle is included. The dual chan- nel amplifiers drive two 4 x 6 in. nounced. The Model XT -1 uses an speakers. It is finished in pyroxylin, audible tone for indicating relative Cartridge 217 and the carrying weight is 20 lbs. VM. gain of a transistor. ESO. A stereo cartridge that incorporates an elliptical stylus is introduced. The manufacturer claims that this car- easily service transistor radios...and make money!

tridge can be used at the higher track- ing pressures required by automatic record changers. Audio Dynamics.

CB Transceiver 218 A CB transceiver is announced. The CB -212 utilizes crystal controlled transmit and receive functions on any

with Exclusive Dyna-Trace Single -Point Probe and Built-in Metered Power Supply and VTVM. age Cek cinuts . e i í s This is the way to profit from transis- Unique Point -to -Point Signal Injection Easily enables you to troubleshoot any stage tor radio servicing. There's no hit or of any transistor radio-fast. miss, no waste of time and work. The Built-in Metered Power Supply six available CB channels. A of the B&K "960" Analyst gives you a com- Makes it easy to operate radio under test. front panel switch determines the Provides from 1 to 12 volts in 11/ volt steps. plete transistor radio service shop in channel in use. A dual power supply is Supplies bias taps. one easy -to -use instrument. It provides Simplifies In -Circuit Transistor Test provided with 117 vac input for Dyna-Trace single -point probe needs only fixed station applications and 12 vdc signal -generator, power supply, the one contact to transistor under test. for mobile applications. Hammarlund. milliammeter, VTVM, battery tester, Gives fast, positive meter indication. ohmmeter, and both in -circuit and out - Built-in VTVM Includes essential high -input -impedance of -circuit transistor tester-all in one. vacuum -tube voltmeter for correct servicing. Oscilloscope 219 Also speeds servicing of tube -type Test All Transistors Out -of -Circuit A portable oscilloscope is an- radios. Brings you new customers, and Meter has "good -bad" scale for both leakage The type 422 weighs ap- and beta; and direct -reading beta scale. nounced. new profit. Net $9995 Also automatically-determines NPN or proximately 20 lbs with "A" Supply, PNP. Meter is protected against accidental including power cord and panel cov- overload and burn -out. er. The are 63/4 by 81/2 by dimensions See Your B&K BaK MANUFACTURING CO. 16 in. It has a bandwidth of dc to 15 Distributor DIVISION OF DYNASCAN CORPORATION Mc, sensitivity to 10 mv/dv and dual - or Write for 1801 W. BELLE PLAINE AVE. CHICAGO 13, ILL. trace operation. A 4 in. rect. CRT, Catalog Canada- Atlas Radio Cora. 50 Win gold, Toronto 19, Ont. York 7, U.S.A. with illuminated graticule, provides .9P21 -T Export: Empire Exporters, 253 Broadway, New 8.2 sq. in. of display area. Tektronix. .. for more details circle 19 on postcard MAY 1965 81 Soldering Gun 304 CAR OWNERS SAY ... NEW LITERATURE A two -page, three -color bulletin, gives specifications and applications of "Terrific," "Fabulous," a 25 to 450 w soldering gun. Wen. "Improves radio 100%!" Audio Wire 300 Voice Actuated Switch 305 A line of audio wire and cable is A voice actuated switch which will described in this 12 -page catalog. The start and stop a tape recorder as you catalog lists all types of single and speak is announced. The unit can be multiconductor audio cables, pertinent used with almost any tape recorder construction details and electrical on the market, the manufacturer says. characteristics. Phalo.

CCTV Camera 306 Sequence Timers 301 This bulletin contains specifications A series of industrial sequence tim- and characteristics of a CCTV cam- VERBA-MATIX ers are described in the four -page bro- America's Prestige era. Applications and mechanical di- chure. Mallory. mensions are also included. GBC. REVERBERATION The only system with RF Power Measurements 302 Microphones 307 4 Transistors Heavy 7 oz. Ceramic - This 56 -page catalog contains in- A 16 -page catalog features a line Magnet Speaker Complete Control Panel (with Reverb % Control) No formation on coax load resistors and of microphones for use in many Drilling, No Screws, for easy installa- attenuators, absorption wattmeters, di- fields - CB, broadcasting, amateur, tion Fits all Cars, Neg. or Pos. rectional wattmeters, coax switch- professional and home recording. (12 volt) All 2 to 40 Ground Speakers es and RF filters. Bird. Turner. ohms No Noise Driving Over Bumps.

Made in U.S.A For complete details see your Distributor or write ET -6 Electronic Projects 303 CB Transceiver 308 This catalog lists a number of elec- A two-color data sheet describes two kinemafix, inca tronic projects. The description and CB transceivers. Features and specifi- 2040 W. Washington Blvd., Chicago, Illinois 60612 price of each project is included. Hen- cations of each model are included. Area Code 312 666-0066 ry Francis Parks. Metrotek. 'i. . for more details circle 40 on postcard MR SERVICEMAN

The NEW STANCOR Part -to -Part Cross Reference Guide is avail- able at your Authorized STANCOR STANCOR TV REPLACEMENT GUIDE Service Parts Distributor. PART TO PART CROSS REFER,

COMPLETE FROM A to Z

Over 11,000 Manufacturers' Part Numbers Cross -Referenced to Stancor Standard Replacement Transformers and Sweep Com- Ask Your Distributor ponents. STANCOR For Your Copy! *With 151 other brands in between.

STANCOR ELECTRONICS ESSEX WIRE CORPORATION 3501 W. Addison Street In products, performance, purpose . .. Essex measures up! Chicago, Illinois 60618

82 ELECTRONIC TECHNICIAN CC -TV 309 included in this six -page folder. Indus- A line of closed circuit television trial Instruments. products is described in this eig'tt- COLOR CODED page booklet. Vidicon TV cameras, RF Interference 313 monitors, lenses, housings, distribution This illustrated 24 -page book de- accessories are cov- equipment and scribes the problems and solutions ered. Blonder -Tongue. of radio frequency interference on mo- NUTDRIYER SETS bile rigs. Hallett. no fumbling... Selective Cavities 310 314 This booklet describes selective cav- Power Supplies contains specifications you reach für ities and how they function. It is de- This catalog and current regu- signed to provide persons in the two- for a line of voltage supplies. Also included the right one way radio industry with a working lated power power supply terms knowledge of selective cavities. Deci- is a glossary of of regulated power every time! bel. and explanations supply capabilities. Kepco.

Power Resistors 311 Diode Cross Reference 315 A 12 -page, two-color catalog de- Thus 19 -page cross reference and scribes a line of vitreous enamel interchangeability for zener and ref- wire -wound power type resistors for erence diodes guide, lists over 4000 various applications. Stock resistance device types, together with their near- values, prices and dimensions are given est equivalents and recommended re- for resistors ranging from 1 to 200 placement types. Motorola. w. Ward Leonard. Antennas 316 This handbook includes data and No. 17 HANDY HV Components 312 specifications on base station anten- BENCH STAND Descriptions and technical data on nas, vehicular antennas, duplexers, power supplies, volt boxes, zener reg- mounting hardware, coaxial cable sys- 7 Most -used sizes ;6" thru ?á" kilovolt - tems and accessories. Communication ulators, insulation test sets, High carbon steel, polished and plated meters, connectors and switches are Products. Precision fit case-hardened sockets Shockproof plastic handles (UL) Make $4.00 Extra Profit Large, readable size indexes For Each Color TV Service Call! BUTTON SWITCH CW 1 ELECTRONICS SAFE l'\, t l MOLDED CASING USE, DEMONSTRATE 7"DIA. 'JI) AND SELL 4 HIGH No. 127 QUALITY SPACE -SAVING WALL RACK (Lockable)

-shaft or mixed -* LOW OTHER SETS, TOO: hollow PLUS A FULL RANGE OF SEPARATE NUTDRIVERS: COST 3/32" thru 3/4" - Regular, Stubby, Extra -long, Midget (Pocket clip) Hanging available through leading electronic distributors Clip XCELITE, INC. included 14 Bank St. Orcnard Park, N. Y. for back Canada: Charles W. ''ointon, Ltd., Toronto, Ont. of TV set 00 Only $5.95 WALSCO ELECTRONICS HAND TOOLS DI V. OF GC -TEXTRON ELECTRONICS. INC. NET Quality screwdrivers, nutdrivers, pliers, Main Plant: Rockford, Ill., U.S.A. Hicksville, L.I.,N.Y. Los Angeles, Calif. wrenches, service kits, and special purpose tools. ... for more details circle 68 ors postcard ... for more details circle 72 on postcard MAY 1965 83 TIPS ON COLOR . . . comes in the shop once in a while, Vertical and horizontal centering however, that refuses to converge sometimes inject Continued from page 53 their own "kinks" well. I can tell you with one sweep- into an otherwise easy procedure. mize focus -change troubles, the fo- ing statement that your problem, in Vertical centering is the worst of- cus should be set to normal viewing most cases, is the yoke. Don't try fender, and if it is turned off by levels with normal picture content. to analyze the yoke, though. You as much as one quarter to half an If this procedure is used, minimum won't find a thing wrong. Generally, inch, the resulting convergence may noticeable focus variation will be the windings in the yoke are very be totally unacceptable. It is gener- obtained when the brightness is slightly skewed and the effect on ally a good idea to use a rule and changed over a reasonable range. each gun in the CRT is slightly dif- actually measure the position of the ferent. This causes a separation of horizontal line Convergence position when the one or another gun which cannot NORMAL -SERVICE switch is thrown Convergence was a dirty word be counteracted by the convergence to SERVICE. The line, of course, with most technicians only a couple controls. Such trouble is most often should be accurately leveled and of years ago. Now, most technicians observed at the left or right side of centered vertically. are fairly proficient at it. A set the screen. Adjusting 4.5 Mc Trap In color work, the 4.5 Mc trap adjustment is more critical than in B/W because the 3.58 oscillator fre- lot . quency beats and generates a very a of good dealers here noticeable 920 kc pattern in the picture. This shows up as broad herringbone interference running through color pictures. Many manufacturers have com- plicated adjustment procedures which require accurately calibrated equipment. I use a simpler method in which only a good scope (rea- sonably flat to about 4.5 Mc) and a station signal are required. The results are at least as good as any

but room for lots more A BETTER WAY TO REPLACE SOLDERED COMPONENTS

LENGTH B" WEIGHT 31/2 OZ. CAN YOU QUALIFY?

Do you have a sound knowledge of radio and/or communications equipment? Have you the desire to install and service this unique equipment? Do you have an established business reputation? Good credit rating? Have you a real interest in Now-remove miniature soldered corn- dynamic new products? ponents in seconds-without damage Do you want to make really big profits? Hollow tip fits over connection; vacuums all solder for easy removal of component. Leaves terminals and mounting holes clean. MANY PRIME AREAS STILL OPEN .. . Then, with 360° contact, it resolders even WRITE TODAY FOR FULL DETAILS! faster and better than regular irons. Han- dles miniature and standard components in printed circuit boards and conventional wir- ing. Self-cleaning. All parts replaceable. 40 5 Pays for itself in Nane watts, 115-v. tip sizes. time saved. $9.95 net East of the Rockies. Address ®.@.{1. electronics communications, inc. Larger model available. See your distributor or write: City State n. y. dept. ET5, 56 hamilton ave., white plains, ENTERPRISE DEVELOPMENT CORPORATION 1102 E. 52nd INDIANAPOLIS, IND. 46205

... for more details circle 27 on postcard ... for more details circle 29 on postcard 84 ELECTRONIC TECHNICIAN CENTRALAB MAKES CO OE TV SERVICING EASIER WITH QUALITY IN DEPTH COVERAGE IN DEPTH

WHEN YOU NEED A CONTROL for a color tv set, you can be sure that Centralab will provide an exact replacement. Rely on Centralab's total coverage: buzz controls, dual concentrics, twins, and of courser all your single control requirements. Centralab coverage goes hand -in -hand with Centralab quality: These units can't loosen, shafts can't pull out. In fact, it's hard to tell the difference from the original manufactur- er's control; but you can rely on Centralab quality and guarantee your replacement.

WHEN YOU NEED A CERAMIC CAPACITOR for a color tv set, you can be sure that Centralab will provide an exact replacement. Rely on Centralab's total coverage: discs and tubulars, any stand- ard voltage, any standard capacitance. Centralab pioneered the ceramic capacitor, has the experience, know-how, and accept- ance to assure you that Centralab quality goes hand -in -hand with Centralab coverage.

WHEN YOU NEED A PACKAGED CIRCUIT for a color tv set, Centralab's is the exact replacement. Centralab invented them and makes most of them (more than 300,000,000 units to date). The R -C net- works are fired on to the sturdy ceramic substrate and the entire unit is Durez coated. That's coverage plus quality.

SEE YOUR CENTRALAB DISTRIBUTOR FOR COLOR TV COMPONENTS

P. 0. BOX 591, MILWAUKEE, WISCONSIN 53201 In Canada: Centralab Canada Ltd., P.O. Box 400, Ajax, Ont.

DIVISION OF GLOBE -UNION INC.

G-6430 ... for more details circle 23 on postcard 85 MAY 1965 other method and better than most. Use a monochrome signal if at all YOU CAN'T AFFORD possible. If a color signal is used 30 watt be sure to turn the chroma gain TO BE WITHOUT down. Try to find a strong station transceiver signal which has a reasonably still THIS MONEY -SAVING, picture. This will make the adjust- ment results a little easier to see. for Industrial TIME -SAVING GUIDE Adjust the fine tuning until a noticable 4.5 Mc hash appears in -Service ----1 the picture. Attach the scope to the video detector output-almost any point beyond the detector will THE ALL NEW RADIO 15IDÑ do (Fig. 2). Sync the scope at the Over vertical rate. Now observe 50,000 TELE the 1 HALLMARK 3000 technicians scope. Turn the 4.5 Mc trap ad- purchased RECEDER the justment and note the "hash" on A rugged unit original CIRCUITRY the sync and in the video. Adjust edition that really of this AND TtN the trap for minimum 4.5 "hash." "popular If a test pattern is means business classic" .. ppERA available, 1 the most Edition this is an excellent signal source. complete Reviuddevised reference When the trap is misadjusted you book ever by A. can actually see the tone modulation assembled. Alfred Ghirardi and Jess E. Dines on the "hash." If a pattern genera- tor with a crystal controlled 4.5 Mc NOW! Completely Revised... sound source is available, this too will make an the one book you'll need in 1965. excellent signal source. (See Fig. 3 and 4.) THIS NEW, up-to-the-minute edition is indispen- sable for you and every other practicing radio Chroma Tips and TV service technician who wants and needs to improve his knowledge of the latest advances Neophytes and pros alike are still SUGGESTED in the field (color television, tuners, transistors). perplexed by insufficient tint con- 1 This money -saving, time-saving guide covers a wider range of electronic subjects than any other trol range, tint control normally lo- 1 FCC Type Accepted 1 book of its kind! The cated at one end and too little 1 compact Hallmark 3000 1 EASY TO USE IN has been engineered 556 FACT -PACKED PAGES chroma. Only three adjustments for busi- 1 ness 1 Contains over 300 carefully selected illustrations. cause most of the trouble: The and industrial service schematics and diagrams. Gives fast, accurate bandpass amplifier coils-follow the 1 where top performance in de- 1 answers that make YOU the authority. Chapter pendable, long range commu- summaries clarify, simplify . even includes manufacturers recommended proce- 1 1 nications is a must! well -thought-out problems and answers to test dure here-and the 3.58 Mc output your skills and improve your knowledge. 1 transformer adjustment. 1 With crystal controlled opera- TEN-DAY FREE More than a This transformer can normally be 1 tion in the 25 to 50 me band, 1 "cookbook," TRIAL OFFER the "3000" has an input adjusted on a color program with 1 1 this valuable Here's how to order power of30watts and features your copy of RADIO the tint control set to mid -range. book covers: AND TELEVISION RE- 1 an improved noise limiter and 1 CEIVER AND Simply turn the slug until - Modern radio CIRCUITRY the flesh unique squelch and OPERATION 1 circuit for 1 television AM and today! tone tints are normal. it is Priced at only $10.00, If not quiet stand-by operation. FM receivers 1 1 The design and you may examine this possible to get normal flesh tones book for ten full Designed to take full advan- structure of basic days in this manner, the 3.58 bandpass receiver components without obligation. 1 tage of the best features of 1 Just fill out and mail amplifier Newest television may be misadjusted. tubes and transistors, the picture tubes the coupon below, 1 1 right now. If you are Again, it is best to follow manu- "3000" uses a fully transis- Color television not fully High -efficiency satisfied in facturers' adjustment procedures for 1 torized mobile power supply 1 tuners every way, you may Transistors return the book and this one. 1 for low power drain. The small 1 owe nothing. Several size means easy installation manufacturers are now 1 1 FILL OUT! MAIL TODAY designing and building their own in any vehicle. 1 1 HOLT, RINEHART AND WINSTON, INC. color chassis. In all probability, Receiver sensitivity is 0.3 µv P.O. BOX 2334, Grand Central Station, New York 10017 more color sets will be manufac- i for 10db S + N/N ratio. Tran- 1 Please rush my copy of RADIO AND TELEVISION sistorized modulator gives RECEIVER CIRCUITRY AND OPERATION, Revised Edi- tured this year than in past years 1 the 1 tion by Alfred A. Ghirardi and Jess E. Dines Hallmark (2483253) for 10-day FREE EXAMINATION. If combined. Many technicians are 3000 maximum I decide to keep it, I will send you $10.00 plus 1 1 postage. transmit modulation and "talk ET-1 now making a good living by speci- power". Available in 115v AC 1 Nome alizing in color sets. And I believe 1 (please print) and 12v DC models. those who have shunned color serv- 1 1 Address icing up to now are missing the col- Write for complete information 1 1 City State Zip or train. I think the multi -colored MI MI MI Mil lIZZ ® MIN edß GUARANTEE: If you are not completely satisfied, caboose return hook within IO days and owe nothing. will soon pass them by- Same unless SAVE: Send check with order and we pay postage. they get aboard without fur- H LO -day return privilege, with money promptly refunded. ther delay. HALLMARK INSTRUMENTS 2620 Freewood Dr., Dallas, Texas, FL 7-0184 ... for more details circle 37 on postcard ... for more details circle 34 on postcard 86 ELECTRONIC TECHNICIAN It's like Getting A Training Course Free...

When You Build A Heat hkitHeathkif Color TV...$399 "Do -It -Yourself" Plus Famous Heathkit Manual Make You An Expert! never seen a color television look so good!" About all we can add are the What better way to learn about color TV than to build one yourself! features for your comparison: And that's exactly what you do with the Heathkit 21" All -Channel, High Built-in Service Center ... includes degaussing coil & dot generator Fidelity Color set. You do the complete job ... mount the parts, wire to demagnetize, adjust & maintain set 26 tube, 8 diode circuit; 24,000 I.F. and high voltage sections are prebuilt & aligned), the leads (tuners, volt regulated picture power Deluxe Standard-Kollsman VHF tuner even converge, align, and adjust the picture with the degaussing coil and with push -to -tune fine tuning for individual channels, plus transistorized dot generator. Takes around 25 hours. and built-in UHF tuner High definition 70° 21" color tube with bonded safety glass And with this superb set, you go a step further. The big 11/4 lb., 138 - Automatic color control & gated automatic gain control Line page instruction manual is an education itself on color TV operation & Thermistor for longer tube life Circuit breaker protection; transformer theory. Hubert Luckett aptly describes it in an article from Popular operated Two hi-fi outputs plus tone control Chassis mounts on Science: "The manual provided with the kit is a masterpiece. It is nearly one-piece metal frame for easy set-up & servicing Only color TV a half-inch thick and lavishly illustrated with drawings, photographs, you can install 3 ways-wall, custom cabinet or either Heath factory - X-ray views of circuit boards, and even 32 plates in full color. Only 28 assembled cabinets 1 -year warranty on picture tube, 90 days on all pages of the 138 -page manual are devoted to the usual step-by-step pro- other parts. Get full details & specifications by sending for your FREE cedures. The rest covers the theory of operation, detailed descriptions Heathkit catalog. Or better yet, use the coupon and order your set now! of each circuit, trouble -shooting, service information, adjustments, and Kit GR -53A, chassis, tubes, mask, UHF & VHF tuners, mounting kit, operation." (See the Heathkit Color TV article in this issue!) special 6" x 9" speaker, 127 lbs. $399.00 And The Performance? TV serviceman E. C. Van Dyke of Baltimore Assembled GRA-53-7, walnut wood cabinet (illust. above), 85 lbs... $115.00 wrote: "After constructing Kit #GR -53A, I can truthfully say that I have Assembled GRA-53-6, walnut -finished hardboard cabinet, 52 lbs...$49.00 COMPLETE TEST LINE FOR EVERY SERVICING NEED! Now Available Kit Or Assembled!

VTVM ... Kit IM -11, $24.95; Assemb. IMW-11, $39.95 Service -Bench VTVM ... Kit 1M-13, $32.95; Assemb. IMW-13, $49.95 AC VTVM ... Kit IM -21, $33.95; Assemb. IMW-21, $52.95 Capacitor Checker ... Kit IT -11, $29.95; Assemb. ITW-11, $49.95 5" Oscilloscope ... Kit 10-12, $76.95; Assemb. 10W-12, $126.95 Audio Generator ... Kit IG -72, $41.95; Assemb. IGW-72, $64.95 RF Signal Generator ... Kit IG -102, $27.95; Assemb. IGW-102, $54.95 Variable -Voltage Regulated Power Supply ... Kit IP -32, $56.95; Assemb. IPW-32, $84.95 Assemb. IPW-20, TV Sweep Alignment Generator, Color Bar 8 Dot Generator, Regulated DC Power Supply ... Kit IP -20, $72.95; $114.95 Kit IG -52, 14 lbs.....$67.95 Kit IG -62, 13 Ilbs.....$64.95 Battery Eliminator ... Kit IP -12, $47.50; Assemb. IPW-12, $59.95

HEATH COMPANY, Dept. 24.5, Benton Harbor, Michigan 49023 HEATHKIT *965 FREE! In Canada: Daystrom Ltd., Cooksville, Ontario Please send FREE 1965 Heathkit Catalog. - 4M+ See these and over 250 D Enclosed is $ , plus shipping. other Heathkits. Save up Please send model(s) to 50% by doing the easy assembly yourself. Send for Name (Please Print) your FREE Heathkit catalog Address today. City State Zip Prices & Specifications subject to change without notice. TE -136J

... for more details circle 35 on postcard MAY 1965 87 YOU AND COLOR TV . . . When the two signals are 90 deg Again, the average plate current out of phase (Fig. 7D) the average will be dependent Continued from page 51 on the amplitude plate current is the same as the no of the control grid signal. on the control grid, the plate cur- signal value. This is true because in From this we find that the aver- rent consists of a series of half-cycle this situation the two signals sub- age plate current varies from a pulses with average value. tract for half the conduction period maximum at 0 deg phase differential When an in -phase signal is ap- and add during the other half. In between the two signals to a mini- plied to the control grid, this signal effect, these changes cancel each mum when they are 180 deg out of adds to the sub -carrier amplitude other out so the average plate cur- phase. The relationship between the and causes the tube to conduct more rent remains constant. A 180 deg signals, phase differential and out- heavily. A corresponding increase phase differential is shown in Fig. put voltage is shown in Fig. 8. in the average plate current is then 7C. In this case you will note that When we apply this relationship noted. The average plate current in the color signal will subtract from in actual practice, the B -Y demodu- this situation (Fig. 7B) will vary the subcarrier voltage and cause lator tube is biased so that the sub- with the applied signal amplitude. the average plate current to be less. carrier voltage causes the tube to conduct. In practice, the color signal (as previously stated) is composed You of B -Y and R -Y voltages added to Stock ONE form one resultant. This voltage, varying both in amplitude and phase, is fed to the control grid of Automotive Speaker each demodulator tube. A simpli- fied demodulator circuit is shown in Fig. 9. The B -Y demodulator But You Can Replace tube is biased so that the subcarrier voltage causes the tube to conduct for a short period every positive half cycle. During this time, the out- put voltage is dependent on the THREE! color signal phase and amplitude. With proper synchronization, the B-Y demodulator will be conduct- ing when the resultant color signal applied to the control grid is com- posed of only B -Y components. This will cause the output voltage of the B -Y demodulator to vary at the B-Y rate. The R -Y component at this in- stant will be zero so the B -Y out- put is unaffected by R -Y voltages. The R -Y demodulator suppressor Tha-'s the big advantage of selling the new Oxford Multi -Impedance at this time is negative so the R -Y tube is cut off and has no output. Automotive Speaker . . . it will replace original units with an im- The R -Y demodulator operates pedance of 10, 20 or 30 ohms. This, of course, reduces your inven- in a similar manner except that it tory and increases your profits! is pulsed into conduction at a dif- And, when you install any Oxford automotive speaker, you can be ferent time and when it is conduct- con=adent o- having used the finest product available. Oxford is ing the color signal is composed of the major manufacturer of the original equipment speakers used only R -Y voltages. The output, by Detroit's "Big three." The know-how gained through producing therefore, at the R -Y plate is vary- these OEM speakers, plus the latest design innovations go into ing at the R -Y rate. The B -Y tube is cut off while the R -Y tube is con- every replacement unit bearing the name Oxford. So for the ulti- ducting. This action is repeated once mate in quality and design ... be sure it's an Oxford automotive every cycle for each tube. speaker. Our detection process is then complete with a reproduction of the original B -Y voltage appearing at the B -Y demodulator plate and a OXFORD replica of the R -Y voltage at the A Subsidiary of Oxford Electric Corporation TRANSDUCER R-Y plate. These voltages are then 2331 North Washtenaw Avenue Chicago 47, Illinois matrixed to form a G -Y voltage CORPORATION / with the three difference voltages then fed to the three CRT grids. ... for more details circle 49 on postcard 88 ELECTRONIC TECHNICIAN The difference signals are either amplified (low level demodulator) before application to the CRT or, in the case of a high level demodula- tor, fed directly to the CRT grids. COMPLETE TUNER Let's take a close look at a practical color demodulator. OVERHAUL

Demodulator Circuitry Recent RCA chassis and many ALL MAKES-ONE PRICE other sets demodulate on the X and Z axis, instead of the B -Y and R -Y axis. These axes were chosen to ful- fill the needs of a special adder sys- tem employed to matrix the differ- PROFIT FROM ence voltages. The demodulator and color dif- ference circuitry employed in the RCA CTC 16 chassis is shown in Fig. 10. In the 6GY6, a pentode,

A Whisper Fan, that is! Installed in your cus- the suppressor grid is designed to tomer's TV, Rotron's amazingly quiet Whisper Fan control current flow in the tube cools components and tubes with 65 CFM of air along with the control grid. The con- to give them as much as 50% more life. That trol grid determines the total can easily save the small cost of the Whisper Fan many times over. You make a happy customer amount of cathode current that will and a good profit on the fan. You save costly flow, that is, to both screen and call backs. plate while the suppressor controls ALL LABOR the number of electrons that fin- AND PARTS QUIET ROTRON ally reach the plate. (EXCEPT TUBES The color signals are taken from TRANSISTORS)* the center tap of the color control, Wd,opei adr. R145, and applied to the control grids of both demodulator tubes. The local 3.58 Mc oscillator signals are applied to the X and Z demodu- lator suppressor grids with the prop- er phase relationship. On a vector diagram, the X axis lies 280.9 deg from the reference COLOR burst phase and the Z axis lags the TIMERS X axis by 62.1 deg. The voltage ap- TRANSISTOR pearing at the outputs of the X and Guaranteed Color Alignment-No AddIt. Charge Z demodulators is not true B -Y and R -Y voltage. Correction voltages Simply send us the defective tuner complete; include tubes, shield cover and any damaged parts with model are applied in the color difference number and complaint. Your tuner will be expertly overhauled and returned promptly, performance re- color difference stored, aligned to original standards and warranted Rotron's Whisper Fan is the quietest air mover amplifiers and true for 90 days. there is for cooling TV sets, amateur radio equip- voltages are applied to the CRT UV combination tuner must be single chassis type; and send in and dismantle tandem UHF :,nd VHF tuners ment, hi-fi components, electronic organs, grids. the defective unit only. similar equipment. Independent laboratory tests Exact Replacements are available for tuners unfit for The cathode resistors in each exchange. (Replacements have shown the Whisper Fan to have an SIL of overhaul. As low as $12.95 stage, R749 and R762 are unby- are new or rebuilt.) just 18 db, quieter than any other cooling device with comparable air volume. And the Whisper Fan passed and have a degenerative ef- is built for a lifetime of trouble free, attention fect on the control grid signal. This free service. Never needs lubrication. action improves the linearity of the Get your share of Whisper Fan profits. Simple, control grid characteristic. fast installation, complete hardware included. The screens are returned to B+ Write today for complete details and name of your through R760 and R761. The Whisper Fan distributor. TV TUNER SERVICE, INC. nearest screen supply must be well -regu- lated to prevent screen current MAIN PLANT: 5713 N. Western Ave., Chicago 45, Illinois EAST: 41-92 Vereor Blvd., long Island City 1, N.M. changes from affecting normal tube CANADA: 136 Main Street, Toronto 13, Ontunio ROTRON operation. 'Major Parts are additional in Canada 12 MFG. CO., INC. At their positive peaks, the sub - WOODSTOCK, NEW YORK carrier signals applied to the sup- ROTRON ORiole 9-2401 pressor grid causes heavy current West Coast: Rotron/Pacific, Glendale, Calif. Canada: The Hoover Co., Ltd., Hamilton, Ont. flow in the plate circuit. During the for more details circle 22 on postcard ... for more details circle 54 on postcard ... 89 MAY 1965 negative peaks all the cathode cur- rent flows to the screen. Detection is achieved because the chroma signal applied to the grid adds to or subtracts from, depending on phase and amplitude, the carrier so easy to use ... signal during plate conduction. This results in a varying color signal at the plate. The demodulator plate load re- SO IMPORTANT! sistors are limited to 3900 12 be- cause a 500 kc bandwidth must be attained. C720 and L705 provide Another Premium the necessary low pass filtering in the X demodulator output. This Nortronics prevents the high frequency com- Product BY MILTON S. KIVER ponents present in the output from SECOND EDITION affecting the picture. A similar fil- 335 pages, $10.95 ter is used in the Z demodulator output. This up-to-date revision intro- This type circuit is called low duces, analyzes, and explains a level demodulator, that is, the signal every facet of color television - present at the output is not strong D from the fundamentals of light enough to drive the CRT grids. In AZIMUTHAMPLIFIER and color to actual installation, TAPE - high level demodulators the CRT ALIGNMENT TAPE RECORDERS operation, and servicing. Step-by- grids are driven directly from the FOR MAGNETIC step, the author takes you through stage output. A circuit of this type the entire circuitry of color TV. will be described later. In this new edition he adds Color Difference Amplifiers much new or supplementary in- The signal present at the plates formation on demodulators, de- of the X and Z demodulators will flection systems, UHF tuners, have to pass through another stage video intermediate frequency, for two reasons. First, the signals are not true color difference infor- color synchronizations, tube de- mation and second, further amplifi- magnetization, dynamic converg- AT -100 Alignment Tape (full -track, cation is necessary to drive the CRT 7.5 ips, I/ professional) is essential for ence systems, and much more. He grids. proper azimuth alignment of tape re- presents and examines virtually Three stages called color differ- corder heads. Selected signals ranging from 40-10,000 cps are also provided for all the latest developments in ence amplifiers (Fig. 10) are used checking playback frequency response components, and the current ad- to matrix the signals and also pre- (NAB Curve). vances in many circuits. pare them for application to the ACCOMPLISHES CRT. Special features include block V706A and V706B receive 4 BASIC ADJUSTMENTS their color signals from their respec- required for any tape recorder: diagrams to introduce receiver cir- tive demodulators. No direct de- cuits and color plates to demon- 1. Head azimuth (placement of head gap modulator signal is applied to at precise right angle to tape move- strate important aspects of color V707A, the G-Y amplifier. The ment). reception and control. cathodes of the three tubes are tied 2. Playback amplifier equalization. together and return to ground 3. Tape head alignment. BUY THIS BOOK AT YOUR BOOKSTORE through R728. Since the grid of 4. Proper record level for 0 VU reading (standard operating level). OR SEND COUPON TODAY TO V707A is essentially at ac ground, N this results in the G -Y amplifier Time to replace McGRAW-HILL BOOK CO., Dept. 23 -ET -55 being cathode driven by a portion P.S. heads? Replace with Genuine NORTRONICS Tape 327 West 41st Street, New York, N.Y. 10036 of the R-Y and B -Y signals. A true Heads-the industry leader in design. Send me Milton S. River's G-Y signal is produced at the plate NORTRONICS heads have continu- COLOR TELEVISION FUNDAMENTALS, 2nd Ed. for 10 days on approval. In 10 days I will re- of V707A. By the same token, since ously set standards in size, mounting mit $10.95 plus a few cents for delivery costs, R728 is common to V706A and and performance. Nortronics has pio- or return book postpaid. (We pay delivery costs neered in laminated core construction, if you remit with coupon. Same examination and return privilege.) V706B, a G -Y component is in- which has set the industry standards. troduced into these stages. When NAME (Print) the G -Y component at present the WRITE FOR FREE COPY OF NORTRONICS ADDRESS cathode adds to the X signal being TAPE HEAD REPLACEMENT GUIDE applied to the grid, true -Y CITY R volt- ages appear at the output. The same STATE 71P CODE is true when the G -Y component %loetizosuce_. For prices outside U.S.. write McGraw-Hill Intl., N.Y.C. 23- ET -55 at the cathode of V706B mixes 8133 Tenth Ave. No., Minneapolis, Minn. 55427 for more details ... circle 44 on postcard ... for more details circle 48 on postcard 90 ELECTRONIC TECHNICIAN with the Z component present at the grid - true R -Y voltages appear at the plate. Choice of the X and Z axis permitted this voltage addi- tion to take place. The output of each difference amplifier is the dc grid. The TO SAY coupled to its proper CRT THIS SPEAKER HAS SOMETHING ATLAS signals on the grids of the CRT SOUND are then mixed with the Y (lumi- EC -10 nance or B/W) signal present at the cathodes and the desired color pic- ture is obtained. Another function performed by these difference amplifiers is dc restoration. A high negative pulse A true breakthrough in product design, ATLAS SOUND's EC -10 is an all-American value in performance and price. Outstanding in established applications, it opens up brand- is applied to from the blanker plate new uses for horn speakers-in intercoms, low -power paging and talkback systems, the common cathodes during hori- mobile and Citizens Band transceivers. Use instead of cones. Install these extras: zontal retrace time. This causes the Performance-Crisp, efficient, big -speaker sound from 6 watts or less ... clean response three tubes to conduct heavily and from 400-13,000 cps. draw grid current. This charges Construction-All-weather design ... high -impact plastic horn with permanent, molded - coupling capacitors C731, C732 in color...die-cast metal parts for extra strength...tough, easily adjustable, steel mount- reinforced phenolic diaphragm. and C726 to a constant potential. ing bracket ... high -efficiency, ceramic magnet and 61/4" fits anywhere ... available in 8 or 45 ohms Thus, the bias of the tubes is at a Utility-Compact (63/e" long, diameter), also specially designed T-3 (25 -volt) and T-4 (70 -volt) line matching transformers. fixed level dependent only on the ... Price: $14.25 net pulse not on the vari- Speaker blanking and in public address speakers and microphone rein- For more on the EC -10 and all your needs able color signal. This action stands, write for catalog ETF-15 serts the dc component of the signal and it is maintained through to the ATLAS SOUND Division of CRT by direct coupling. us slue AMERICAN TRADING AND PRODUCTION CORPORATION 1419-51 39th Street, Brooklyn, New York 11218 High Level Demodulator Canada: Atlas Radio Corporation, Toronto A Zenith high level demodulator THIRTY YEARS OF LEADERSHIP IN COMMERCIAL SOUND 16 on postcard schematic, chassis 25MC30, is ... for more details circle shown in Fig. 11. A signal from the local 3.58 Mc oscillator drives the deflection plates of each individual demodulator tube (6JH8 beam deflection type) push recise Scope pull through the quadrature trans- former. The chrominance signal is fed to the grids of V12 and V13. Each demodulator tube has two outputs which are 180 deg out of Spectacular! phase. Pin 9 output of V12 is the leading electronic distributors) detected B -Y color difference signal (now going on at and the R -Y signal appears at Pin 9 of V13. These color difference signals are applied through filters to the proper CRT grids. The G -Y signal is obtained by combining the -(R-Y) and -(B -Y) signal outputs at the plates (Pin 8) of the respective demodulator tubes. Resistors R16, R37, R38 and R39 form the mixing network to produce the proper G -Y signal which is applied to the green guard. Output of the high level demodu- Four top quality scopes (kits or wired) including a low cost color scope, Model 3151, lators is great enough to drive the K. $89.95, W. $137.95 a top value in a 5" general radio and TV scope, Model 315, CRT grids without requiring addi- K. $79.95, W. $113.95 two professional performance scopes the 7" Model 300C, Illustration K. $169.95, W. $222.95, and the 81/2" Model 308, K. $179.95, W. $249.50. Prices tional amplification. catalog write: Credit: RCA Institutes and "Color slightly higher in West.Save now at your Precise distributor.For free 1965 by Mil- Television Fundamentals," ilePRECISE ELECTRONICS & DEVELOPMENT DIV. OF DESIGNATRONICS, INC ton S. Kiver, McGraw-Hill Book 76 EAST SECOND STREET, MINEOLA, NEW YORK 11501 Co. ... for more details circle 53 on postcard MAY 1965 91 president of Corning Glass International said construction will begin immediately on a 40 -acre site at Suzano, 28 miles east of Sao Paulo. The 128,000 sq-ft plant is ex- pected to be in full operation by mid -1966, and will employ approximately 400. jjvMLAB

TV Picture, Receiving Tube Sales Factory sales of TV picture tubes increased 14.4 per- cent in December 1964 to 761,925 units as compared to 665,990 units in December 1963, the Electronic Industries Association's Marketing Services Dept. reported. Dollar volume was up, too, but only slightly (0.5 percent from BUSS $12,461,408 to $12,521,528. Unit sales of picture tubes for the full year of 1964 FUSEH were up 6.2 percent to 9,513,121, as compared to 8,955,434 for 1963, but dollar volume declined 1.5 per- LAMP INDICATING SERIES Hi AND H cent from $167,269,408 in 1963 to $164,790,701 in 1964. FOB x 1 AMU x 1x INCH FUSES Factory unit sales of receiving tubes for December 1964 increased 2.8 percent to 31,423,000 from 30,557,000 Quick, positive, visual identification of faulted in December 1963. Receiving tube sales for the full year, circuit. Bayonet type, transparent knob permits however, were down 7.1 percent to 367,788,000 in 1964 indicating fight to be readily seen. from 395,544,000 in 1963. Fuseholier designed to withstand severe vibra- tion. Terminals held mechanically as well as by solder. Bendix High -Voltage Holder can be used in panels up to 3/16 TV Transistors inches thick. High -voltage transistors for television receiver circuits have been developed by the Bendix Semiconductor division. b) Write for BUSS The silicon and germanium transistors, designed for Bulletin SFB horizontal and vertical deflection circuits, "can provide lower driver power levels, simplify yoke design, and reduce the size and cost of the output capacitor and transformer." BUSSMANN MFG. DIVISION, McGraw -Edison Co., 54 Louts, Mo. 63107 BUSS : the complete line of fuses ..

NEWS OF THE INDUSTRY

1 GMW FUS USE SIZE and HWA Suss ONLY .270 x .250 FUSEHOLDE R INCHES Norman Triplett Elected President AEM Norman Triplett has been elected president of the Association of Electronic Manufacturers, Inc. - Central BUSS Division. Mr. Triplett is executive vice president of mar- keting, the Triplet Electrical Instrument Company, Bluff- VISUAL ton, Ohio. He has been active for many years in the INDICATING IIIIIII organization of manufacturers who sell their products through electronic parts distributors; he has served as a Sub -Miniature vice president and director of AEM-Central and its prede- cessor organization, the Association of Electronic Parts FUSE - HOLDER COMBINATION and Equipment Manufacturers, Inc. For space -tight applications. Fuse has window for Triplett succeeds Walter A. Clements of Littlefuse, inspection of element. Fuse may be used with or Des Plaines, Ill., in the presidency. He will serve a one without holder. year term. He has also been elected to represent AEM- Fuse held tight in holder by beryllium copper Central on the Board of Directors of Electronic Industry Contacts assuring low resistance. Holder can be used with or without knob. Knob Show Corporation. makes holder water-proof from front of panel. Military type fuse FMO1 meets all requirements of MIL -F-23419. Military type holder FHN42W meets Corning To Build Plant in Brazil all military requirements of MIL -F -I 9207A. A plant to manufacture glass television bulbs for the Latin American market will be built near Sao Paulo, Write for BUSS Brazil, by Vidros Corning Brasil, S.A., a subsidiary of INUMM Bulletin SFB Corning Glass Works. Robert D. Murphy, chairman, and Forrest E. Behm, ... for more details circle 21 on postcard 92 ELECTRONIC TECHNICIAN uniformity in records and needles to simplify marketing and increase sales of records and replacement needles. All that remains is to achieve unanimity in future manu- facturing," observes Jensen. "I believe that the chances of agreeing on one speed and one size for records is better than anytime since the introduction of the L -P record." Jensen feels that 33 rpm will become the standard speed for records played on a single size spindle. As for record sizes, he believes that the seven -in. and ten -in. sizes will eventually give way to the larger 12 -in., despite the teen- age trend to favor the smaller seven-inch 45s. As far as needles are concerned, Jensen notes that currently 15 types of needles make up 85 percent of all needle sales and he predicts that these will "boil down" to about ten needles covering all phonograph types.

Belden Earnings Belden Manufacturing Company today reported that its earnings and sales set new company records in 1964. Net profit for the year increased 39 percent to $2,350,427 or $2.91 per share compared with $1,692,740 or $2.10 per share a year ago. The previous high of $2.70 per share was established in 1962. Sales for the period ending December 31, 1964, rose to $42,256,221 compared to $35,924,858 last year, an increase of 18 percent. Construction of a 39,700 square ft building was com- Above standard types available in any number of Joles- pleted in August, 1964, at the firm's plant in Richmond, From 1 to 12... plus other types for every applicaticn Indiana. In 1965, as previously announced, the company will construct two additional buildings at Richmond which will add approximately 93,200 sq ft. These three buildings are expected to provide for the expansion of manufactur- ing facilities for about five years.

MFG. DIV., McGraw Edison Co.. ST. LOUIS. MO. 6.31

... a of unquestioned high quality

Screw type kno by James E. Harrison, designed for easy according to the announcement gripping, even marketing manager of the division. with gloves. Has He said the new transistors also will enable engineers a "break -away" "to design circuits for higher output voltages with increased test prod hole power supply efficiency at lower cost." in knob. The new line, he said, includes silicon NPN transistors that feature collector -to emitter voltages to 700 v and germanium diffused alloy power (DAP) PNP transistors Screw type slotted with collector -to -emitter voltages to 325 v. Switching is knob that is at 6 amperes. recessed in holder accomplished in less than two microseconds body and requires use of screwdriver to remove or insert it. Philco Cabinet Plant Addition Philco Corporation will begin a half -million dollar addition to its Watsontown, Pa. cabinet plant this spring BUSS Space Saver Robert Austin, plant manager, announced. The money will be used to construct an 80,000 sq ft warehouse at the plant site. The appropriation is in addi- tion to a $150,000 modernization program in progress at Panel Mounted Fuseholders the plant. "The warehouse," Mr. Austin said, "will be used for Fuseholder only 15/s inches long, extends just the storage of finished wood cabinets used for television, inch behind front of panel. Takes 1/4 x 11/4 inch fuses. high fidelity phonographs and radio sets assembled at Holder rated at 15 ampere for any voltage up to 250. Philco's consumer electronics plant in Philadelphia. Military type available to meet all requirements of MIL -F-19207A. Jensen Predicts Record Uniformity Phonograph records will all become uniform in speeds and sizes within the next five years. Write for Buss Bulletin SFH-10 So predicts Karl Jensen, president of Jensen Industries. Jensen also sees the day when no more than ten types of needles will be used in phonograph equipment. "Everyone in the industry agrees on the need for more ... for more details circle 21 on postcard MAY 1965 93 add an fm -stereo service center OF THE INDUSTRY with this one new sencore unit!

'Friends of Service' Award For the third consecutive year Philco Corp.'s Parts and Service Department has received the "Friends of Service" Award of the National Alliance of Television and Elec- tronic Service Assns. (NATESA).

01 111/t C. Howard Tomlin, Philco's general service manager, (111/ It « ' ." received the award on behalf of the company after ad- dressing NATESA's 1965 Spring Director's Conference at the Lafayette nNALvi[F Hotel in Little Rock, Ark. The presenta- NEFPTOR¡'ND 1! FM MUITIRLE%. SENCOREM%159 tion was made by Lyle Green, NATESA's East-Central --ro G '' >..,1-. vice president.

Norelco Appointments Two appointments of manufacturer's representatives for Norelco radios were made today by North -American Philips Co., Inc. Charles W. Butler, 336 Fourth Avenue, Pittsburgh 27, Pa., will handle the Norelco radio line throughout western Pennsylvania, West Virginia and western Maryland. Morecock-Whitson, Inc., 16011/2 East Boulevard, Char- lotte 3, N.C., will serve as manufacturer's representative for North and South Carolina. Norelco markets a line of AM/FM and FM stereo radios including portables, table models and console com- THE SENCORE MX129 FM STEREO binations.

MULTIPLEX GENERATOR & ANALYZER

FM -Stereo growth continues to mount and is fast becoming as big a field as Color TV. This means more FM -Stereo "TORQUE WRENCH" MANUAL service business for you, now and in the future. Is your shop equipped? It can be completely and economically - SENT - with the MX129, the FM -Stereo "Service Center in a UPON REQUEST Case." The instantly stable, 19 -Transistor, crystal controlled MX129 is the most versatile, most portable (only 77/2 pounds), most trouble free and efficient multiplex unit on the market - just like having your own FM -Stereo trans- mitter on your bench or in your truck. Powered by 115 volts AC, it produces all signals for trouble shooting and

aligning the stereo section of the FM receiver . can be used to demonstrate stereo FM when no programs are being broadcast. Self-contained meter, calibrated in peak to peak volts and DB, is used to accurately set all MX129 controls and as an external meter to Formulas measure channel separator at the FM- Applicatio Stereo speakers. NO OTHER EQUIP- 50 Engineerin MENT IS REQUIRED. only Screw Torque'` Adapter Prob" SIGNALS AVAILABLE FOR ALIGNMENT, TROUBLE SHOOTING AND General Pri ANALYZING: FM -RF carrier with composite multiplex audio signal with 38kc sup- pressed carrier, 19kc pilot and ó7kc SCA signals Multiplex signal formed by 60 or 1000 cycle internal tones or any external signal Full control over left and right channel amplitude (modulation) External ó7kc SCA signal available for trap adjustment Composite signals available for signal injection FM detector professional quality - that's the difference! / URE{/ia N/ CO. SON QUALITYo/LL/NO/5

Manufacturers of over 85% of 426 SOUTH WESTGATE DRIVE ADDISON, ILLINOIS the torque wrenches used in industry

... for more details circle 56 on postcard ... for more details circle 62 on postcard 94 ELECTRONIC TECHNICIAN Fidelitone Representative top money maker in H. A. Prince, sales manager of Fidelitone, Inc., Chicago, has announced the appointment of a new representative, the service business the Steve Fisher Sales Company of Brooklyn, N.Y. They will represent the company in the five boroughs of New York City, calling on distributor accounts. In addition they will cover all of Long Island, Westchester County, Rockland County, Northern New Jersey and as far south as Trenton.

Zenith Hearing Aid Zenith announced the development of the Vocalizer, a new hearing device to improve the voice of profoundly deaf children and adults who previously were unable to hear and recognize "auditory clues," thus preventing them from controlling their voices. Announcement was made by E. M. Kinney, president of Zenith Hearing Aid Sales Corporation, to clinicians and Zenith dealers throughout the country. He reported the results of extensive Zenith Laboratory testing and a special pilot program at a major school for the deaf.

Harman-Kardon Rep Harman-Kardon has appointed the Cartwright & Bean Company as its Florida representatives for the Commercial Sound Div. The firm presently represents Harman-Kardon in the southeastern states. They have offices in Memphis, Tenn.; Atlanta, Ga.; Metaire, La.; Charlotte, N.C. and Miami, Fla. The announcement was made by William Menezes, sales manager of the Commercial Sound Div. NEW IMPROVED SENCORE CR133

Mes. ? Rebuild Color Tubes ? ? ? CRT CHECKER & REJUVENATOR

2t/ß y íaí1 The new, improved CR133 CRT Checker is designed to test all present picture tubes - and it's ready for future Windsor Equipment tubes too! Two plug-in replaceable cables contain all Handles Color & Bond- sockets required. The compact, 10 lb., CR133 checks CRT control grid cut-off capa- ed -Face As Well As emission, inter -element shorts, gas and expected life. Checks all tubes: conven- Black -and -White Tubes. bilities, tional B&W, new low drive B&W, round color tubes and new rectangular color picture tubes. Exclusive variable So- 2' at? G2 Volts from 25 to 325 Volts insures non -obsolescence newly announced "semi-low" G2 CRT tubes. Rebuilding with Wind- when testing New Line Voltage Adjustment insures the most accurate is a QUALITY sor tests possible. Uses well -filtered DC for all checks to avoid PROCESS ... and tube damage and reading errors. Color guns are indi- vidually tested as recommended by manufacturers. Ex- PROFITABLE ! ! ! clusive automatically controlled rejuvenator applies re- Rebuild Color Tubes for juvenation (ACR) voltage as required by individual tube over -rejuvenation or a Cost of $11.75 each condition; precisely timed to prevent The ACR feature is most useful for color ...You Sell them for??? tube damage. tube current equalization to insure proper Equipment Windsor tracking. Hand -wired and steel -encased for pays for itself in a few protection of meter and panel in truck or $8995 months. shop, the new improved CR133 is only .. .

Financing Available The famous CR128 CRT Checker and Rejuvenator is similar Free Training at our to above, but with a three position G2 slide switch and Plant without Line Voltage Adjustment at $69.95 Write for our Booklet "The Open Door to TV Profits" professional quality - that's the difference! WINDSOR ELECTRONICS, INC. Equipment Division 999 N. Main St., Glen Ellyn, Illinois 426 SOUTH WESTGATE DRIVE ADDISON, ILLINOIS

circle 57 on postcard ... for more details circle 69 on postcard ... for more details 95 MAY 1965 america's most popular tube tester NEWS OF THE INDUSTRY

G -E Silicone Distributor R. V. Weatherford Co. of Glendale, Calif., has been named a distributor of General Electric silicone products for California. The firm is a distributor serving the elec- tronic industry in California, Arizona and Nevada. The announcement was made jointly by R. T. Daily, general manager of G -E's Silicone Products Dept. and R. V. Weatherford, president of the R. V. Weatherford Co.

USL Appoints Sales Reps United Scientific Laboratories announces the appoint- ment of 23 sales representatives throughout the U.S. Ac- cording to Bernard Levine, president, additional repre- sentatives will be appointed. These reps are marketing the company's line of CB transceivers.

Olympic Adds 12 -in. Portable A new 12 -in. personal portable television set in a choice of three color combinations has been added to Olympic's portable television line, according to Morton M. Schwartz, president of Olympic Radio & Television Sales Corp. This model is Olympic's first entry into the small screen tele- vision category and expands the line which now includes 12, 16 and 19 inch portable units.

THE NEW SENCORE TC130 TUNER MIGHTY MITE III TUBE TESTER END TV

New in looks and compactness, updated with many exclu- sive features. The MIGHTY MITE tester, long America's CALLBACKS most popular tube checker because it has the versatility with MUM, and reliability professional servicemen demand! The %TRONKS iM MIGHTY MITE Ill checks them all - more than 2,500 tubes CHEMTRONICS plus picture tubes, including the new frame grid tubes IMPROVED (has four extra sockets for latest tubes). It's fast and thorough, checks for control grid leakage, then, with the TUN-O-LUBE flick of a switch, tests for interelement shorts and cathode CIEMTRONICS emission at full operating levels. Uses costly moving coil NEW! NONINFLAh1MA3' TUNER WAWA meter for high sensitivity (100 megohms) to find those "tough dog" tubes other low -sensitivity testers miss. In versatility, reliability, porta- TON bility and operating simplicity, the TC130 is your best buy in tube checkers at $74"

COMPARE THESE MIGHTY MITE III FEATURES: Lower voltage for Nuvistors and all frame grid tubes Unique TUBE circuit tests for inter -element shorts, each and every element CONTAINS Checks 'C-3tho ,.eteri' cathode emission at full operating levels Checks control grid leakage Cleans Faster, Lubricates Longer! at 100 megohms sensitivity, like "eye tube" testers. Will not harm plastics "krn ano ALL 101 Speed -indexed set-up cards greatly reduce look -up time Simplified More powerful spray panel layout speeds checks, prevents errors Burn -out proof, stick - Will not detune TV tuner proof meter Sturdy, all -steel case, rubber feet Styled for modern, professional look SERVICEMEN: For all your chemical professional quality - that's the difference! needs, see the Chemtronics Display at your Distributor! CHEMTRONICS INC. 1260 Ralph Avenue, Brooklyn, N.Y. 11236 426 SOUTH WESTGATE DRIVE ADDISON, ILLINOIS ... for more details circle 58 on postcard ... for more details circle 25 on postcard 96 ELECTRONIC TECHNICIAN Olympic Sales Manager Bill Briggs has been appointed sales manager of Olym- at last... pic of Southern Calif., wholly -owned subsidiary of the instant color patterns Olympic Radio & Television Div. of Lear Siegler, Inc. A veteran of the TV industry, Briggs has been with the at your finger tips. . Olympic branch since its opening in 1958. zero warm-up time +rt

0111113111111105

Mt. CM MIT, P11114

SEPVCOF;E ccna orurr MCP crraiAro. .,,.+,: 0 0.

Our Cover Our cover this month was supplied by Motorola. Equipment includes a Motorola color TV chassis. Test instruments: (A) Audio generator, fB) VTVM, (C) color generator, (D) scope, (E) color generator, THE ALL NEW SENCORE CG135 DELUXE (F) CRT tester, (G) variable ac power supply. TRANSISTORIZED COLOR GENERATOR

The big push is on in Color TV. Equip yourself now with the new, solid state Sencore CG135 and cash in on the zooming volume of new service business as Color -TV booms! Instant, service -ready RCA standard color bars, cross -hatch, white dots and individual vertical and hori- zontal bars enable you to set up or trouble -shoot more Color TV sets per day; earn top money in this fast growing field. It's an analyzer too: Color gun interruptors, ARE YOU CASHING -IN service unmodulated video for chroma circuit trouble isolation and ON THE PROFITABLE unmodulated sync pulses to keep Zenith receivers in sync for this test, make color trouble shooting a snap. Sturdy 2 -WAY RADIO SERVICE BUSINESS ? all -steel contruction for rugged, heavy duty in the field or shop. Another IBest Motorola will train you for this rewarding, elite profession * Buy in profit -building service instruments $14995 that * Send for our FREE EVALUATION EXAM. Prove to yourself from Sencore at you are ready to learn FM 2 -way radio servicing.

Opportunities in 2 -way radio servicing are virtually unlimited. COMPARE THESE FEATURES: SEE WHY THE CG135 IS IN A CLASS Just one of the hundreds of successful Motorola Service BY ITSELF "'we would be pleased to interview any graduate Stations writes, GE "Unijunctions" to of your school that has received some training in 2 -way radio Solid state construction employs high priced stable patterns maintenance. We are an established firm, 10 years old, with develop six "jump out proof counters" that guarantee as a promise of expansion governed by our ability to obtain com- at all times with no warm-up Standard RCA licensed patterns petent technicians." Get all the facts today. There is no shown on schematics throughout the industry Handy universal color obligation and no salesman will call. gun interruptors on front panel Lead piercing clips insure non - 4.5mc obsolescence CRT adaptors optional Crystal -Controlled fine Sound Carrier Analyzing Signal to insure correct setting of TRAINING INSTITUTE 3 IMMOTOROLA tuning control RF output on Channel 4 adjustable to Channel 4545 West Augusta Blvd. Chicago 51, Illinois Dept. AEH519 No or 5 from front of generator when Channel 4 is being used D Send me FREE entrance exam. batteries to run down; uses 115 V AC Less than one foot square, Send full details on Home Study Course on FM 2 -way Radio weighs only 8 lbs. Servicing Send me details on how you can help me prepare for an FCC professional quality - that's the difference! License.

Name Occupation

Address ILLINOIS City Zone State 426 SOUTH WESTGATE DRIVE ADDISON, 1. ... for more details circle 46 on postcard ... for more details circle 59 on postcard 97 MAY 1965 SPRAY IT . .

it's here! most advanced Continued from page 59 Dielectric Coatings The third group breaks down into two types, one color TV test instrument specifically for high voltage applications and the other a general-purpose high dielectric for broad application - particularly for protecting electronic components ever developed from moisture absorption. The first product is useful on flyback transformers and yokes for eliminating high - voltage arc -over and corona discharge. The second comes in a variety of colors and the clear variety (Vinyl Copolymer), is particularly useful for sealing out moisture and corrosive fumes in electrical, electronic and various other equipment. Some brand names are: Hi -Volt, Insul-Volt, K-29, Koloid, No Arc and Quel - spray. Refrigerants This group is relatively new and most technicians say these products, when used intelligently and not in a haphazard guessing game, are real timesavers. A suspected intermittent capacitor, for example, can be frozen to approximately -50°F in one or two seconds - revealing defects almost instantaneously. These products are also used in mechanical applications - shrink-fitting bushings, shafts, sleeves, etc. They are OBSOLETES ALL OTHERS also useful when soldering delicate parts. Some brand ELIMINATES ALL GUESSWORK names include: Chill-It, Freeze -Mist, Frost Aid, Merit- Kool, Spra-Freeze, and Zero -Mist.

A sensational new color generator with 4 major Lectrotech exclusives . plus all of the time -proven standard features . in one compact, portable unit. For the first time. you can install and service color TV completely, accurately and faster! Here are the facts:

EXCLUSIVE-COLOR VECTORSCOPE-Until now, available only n $1500 testers designed for broadcast. Accurately measures color demodulation to check R -Y and B -Y plus all 10 color bars for color phase angles and amplitude, A must for total color and those hard to get skin tones. EXCLUSIVE-SELF-CALIBRATING - Adjust timing circuit with- out the use of external test equipment. No need to return unit to a factory for adjustment. EXCLUSIVE-DIAL-A-LINE - Now, you can adjust horizontal line to any width desired from 1 to 4 lines wide. EXCLUSIVE-SOLID STATE RELIABILITY - Only two tubes are used in combination with fully transistorized diode -rectifier circuit. "' ULTIMATE PLUS- the V7 produces all Crosshatch, Dots, Vertical only, Hori- zontal only and Keyed Rainbow Patterns. RF at channels 3, 4 or 5. Video Output (Pos. and Neg. adjustable) for signal injection trouble -shooting. Red -Blue -Green Gun Killer. All 'PERFORMANCE transistor and timer circuits are voltage regulated to operate under wide voltage ranges. Lightweight, compact Request Tubes Made With only 81/4" x 71/2" x 121/2". Net 189.50 - GRIFFITHS GUN MOUNTS assigned and produced by the men who introduced and developed the modern approach fo TV testing - Bill Grossman and Bob Karel. Griffiths unique and patented method of treating cathodes For the full story on the V7, write for complete catalog or (processed in an air-conditioned, humidified soe your distributor. atmosphere) results in the closest tolerance of l7nt l J tubes. For the mark of quality.... Ask for the Griffiths Grid, "the grid with the Complete color bar generator with all the features lid." V6 of the Lectrotech V7 except the Vectorscope. Only 99.50 GRPFF11THS Distributors: Phone or Wire Collect. LECTROTECH, INC. R1 1301ItT2O E. Landen Avenue, linden, N. J. P.O.BoxUg 602 1737 Devon Ave. Chicago, III. 60626 Area 312 465-2622 Area Code 201 .925-7300

... for more details circle 42 on postcard ... for more details circle 33 on postcard 98 ELECTRONIC TECHNICIAN Solvent -Lubricants One of the oldest groups in application, perhaps, includes solutions for removing and preventing rust and corrosion, for removing "locked" screws and nuts. Some types make it possible to easily remove "frozen" yokes that otherwise defy removal from CRT necks without damage to the yoke. Some can be used on tape recorder and record changer mechanisms to pre- vent corrosion in humid and chemically -contaminated atmospheres. Some brand names are: Chem -Oil, E -Z -Off and Pen-A-Lube. Plastic Cements Although these products are extensive and exist outside of the general aerosol category, two relatively new products should be mentioned here as useful service aids. Called "Magnetic Cement," this product is designed to repair flyback and yoke cores, broken loopsticks, powdered iron cores and slugs. The manufacturer claims the product will renew the broken component to its original performance and efficiency. The second product, called "Plasti-Patch," is said to be composed of a powdered plastic and a liquid plastic. When mixed together, the two plastics form "My shop's been loaded... a jelly -like mass that can be used as a cement or as a molding material to repair broken knobs, radio cabinets, since I've had meter cases, screw mounts on cabinets and plastic tuner shafts. When it hardens, the manufacturer says, my FCC License." it can be filed and drilled. When used properly - for the specific purposes "And I could kick myself for not getting it sooner. I'm pulling in intended - all of these products can save time and all kinds of mobile, marine and CB business that I couldn't touch make your job easier. before; have even had some calls to work on closed-circuit television. I've hired two new men to help out and even with them, I'm two weeks behind." And so it goes. Once you have that FCC Ticket, you open the door to all kinds of new business. And that's not all. The knowledge you need to pass the FCC exam gives you a fundamental understanding of all electronics. You'll find you can do more work in less time .. . work on almost any kind of electronics gear. What's the best way to get a Commercial FCC License ... and still keep up with your work? Thousands of men will tell you "Cleveland Institute of Electronics". CIE has been preparing men for FCC License exams since 1934. What's more, they back their Home Study Tomorrow's standards in; Licensing Programs with this remarkable money -back offer: A CIE FCC License course will quickly prepare you for a Commer- cial FCC License. If you fail to pass the FCC examination ... on the very first try ... after completing your course, CIE will refund all COLOR GUNS your tuition. You get an FCC License ... or your money back! Send coupon today for CIE's FREE informative booklet "HOW GET A COMMERCIAL FCC LICENSE". Cleveland Institute by TO are set today of Electronics, Dept. ET -17, 1776 E. 17th St., Cleveland, Ohio 44114. SUPERIOR ELECTRONICS SEND COUPON TODAY FOR FREE BOOKLET Recent evidence of SUPERIOR'S ability to meet the constant challenge Cleveland Institute HOW TO GET A of the swiftly changing picture in the cathode ray tube industry, is a COMMERCIAL COLOR GUN of advanced design, manufactured by SUPERIOR, that of Electronics FCC LICENSE has established new records for performance and reliability. 1776 E. 17th St., Dept. ET-17 Some things however, like working closely with the world's major pro- Cleveland, Ohio 44114 ducers of cathode ray tubes; SUPERIOR'S policy of personal attention Please send FREE Booklet "HOW TO GET A COM- to individual requirements; and SUPERIOR'S experience as the world's MERCIAL FCC LICENSE", without obligation. leading exclusive manufactuer of electron guns, remain unchanged. When you order, select with confidence the gun you can depend on- Your occupation SUPERIOR. Your assurance comes from the traditional high quality of all SUPERIOR GUNS-COLOR AND BLACK & WHITE COMMERCIAL Name Age TV, INDUSTRIAL, MILITARY, SPECIAL PURPOSE and EUROPEAN tube (please print) types. ©Superior Electronics 1965 Address County ELECTRONICS CORPORATION City State Zip SUPERIOR since 1934 208-212 PIAGET AVENUE CLIFTON, NEW JERSEY TEL: 772-2500 A leader in Electronics Training ... L J ... for more details circle 63 on postcard 99 MAY 1965 TRANSISTORIZED ADVERTISERS INDEX WORLD'S POWER CONVERTER Aerovox Corporation 74 Antenna Specialists Co. 12 VOLT DC to 117 VOLT AC 78 Antennacraft 75 FINEST Arco Electronics, Inc. 20 dMie ONY $G9.9 5DNETR Armco Steel Corporation 39 Arrow Fastener Company 76 POWERFUL 125 WATT CONTINUOUS Atlas Sound 91 DUTY. PROVIDES 117 VOLT 60 B & K Manufacturing Co. 71, 73, 81 CYCLE A.C. BY PLUGGING INTO Blonder -Tongue 24 CAR OR BOAT 12 VOLT CIGARETTE LIGHTER RECEPTACLE. Bussmann Mfg. Div. 92.93 Castle TV Tuner Service, Inc. 89 PLUGS Centralab 85 INTO Channel Master Corp. 35-36 CIGAR LIGHTER Chemical Electronics Engineering, Inc. 72 Chemtronics, Inc. 96 Cleveland Institute of Electronics 99 Columbia Wire & Supply Co. 78 E. C. I. Electronics Communications, Inc 84 EICO Electronics Instrument Co. 41 Enterprise Development Corp. 84 ERSIN 1' Finney Company 28-29 MODEL MADE GC Electronics Company 80 BX 125 IN U.S.A. Greyhound Corporation 65 HULTICORE . Ó ASK YOUR ELECTRONIC Griffiths Electronics 98 PARTS DISTRIBUTOR FOR Hallmark Instruments 86 Heath Company 87 Hickok Electrical Instrument Co. 77 Designed and Manufactured by: Holt, Rinehart and Winston, Inc. 86 Jerrold Electronics Corp. 37 JFD Electronics Corp. 42-43 WORKMAN ieaTetic Kinematix, Inc. 82 ONLY SARASOTA FLORIDA PRODUCTS, I 50C Lafayette Radio Electronics Corp. 67 BUY IT AT RADIO-TV Lectrotech, Inc. PARTS STORES for more 98 ... details circle 71 on postcard MULTICORE Littelfuse, Inc. 79 SALES CORP. PORT WASHINGTON, N. Y, McGraw-Hill Book Co. 90 ... for more details circle 50 on postcard Mercury Electronics Corp. 26 Motorola Training Institute 97 send for New FREE ... with New Multicore Sales Corp. 100 TRANSISTOR Nortronics, Inc. 90 CRYSTAL OSCILLATOR Oxford Transducer Corp. 88 CATALOG CIRCUITS Parts Unlimited, Inc. 100 Perma-Power Company 66 3 PLANTS TO SERVE YOU BETTER Philco Corporation 44 HERMETICALLY SEALED Precise Electronics & Development Div. 91 PRECISION GROUND Radio Corporation of America CUSTOM-MADE RCA Electronic Components & NON -OVEN CRYSTALS Devices 4th Cover, 22, 30 Gold or silver plated, spring mounted. vacuum RCA Institutes, Inc. 34 sealed or inert gas, high freq. stability. 10 milliwatt max. current cap. Meet mil. specs. RCA Sales Corporation 19 I000KC to I600KC (Fund. Freq.) P Rotron Mfg. Company 89 ELECTRONIC TECHNICIANS ... 1601KC on -Rest0urea. to 2000KC (Fund. Freq.)s_. INCREASE YOUR EARNINGS WITH 2001KC to 2500KC (Fund. Freq.) ___ 4.00 Sarkes Tarzian Tuner Service Div. 27 2501KC ea. to S000KC (Fund. Freq.) -_ 3.50 ea. A PARTS UNLIMITED 5001KC to 7000KC (Fund. Freq.) _ 3.90 ea. Seco Electronics 38 7001KC to 10,000KC (Fund. Freq.) ___ 3.25 ea. ELECTRONIC CENTER FRANCHISE 10,001KC to 15,000KC (Fund. Freq.) 3.75 ea. Sencore, Inc. 94-95, 96.97 1SMC to 20MC (Fund. Freq.) 5.00 sa. OVERTONE CRYSTALS Sprague Products Company 23, 25 The Parts Unlimited chain, nationally 15MC to 30MC Third Overtone ..._$3.85 recognized as a pioneer and leader in 30MC ea. Stancor Electronics 82 to 4OMC Third Overtone ._ 4.10 ea. 40MC to 65MC Third or Fifth Overtone the field of retail electronic sales and 4.50 ea. Sturtevant Co., P. A. 94 65MC to 100MC Fifth Overtone 6.00 ea. service is re -offering for a limited time, DRAKE 2-B Receiver Crystals $4.00 Superior Electronics Corp. 99 its valuable franchise to choice appli- (All Channels-Order by Freq.) Sylvania Electric Products, cants. OVEN -TYPE CRYSTALS Inc. If you are established in your own For Motorola, GE, Gonset, Bendix, etc. 3rd Cover, 33 business and want to convert to a Add $2.00 per crystal to above prices Texas Crystals 100 opera- SUB -MINIATURE PRICES slightly higher streamlined, smooth -functioning Turner Microphone Company 76 tion guided by bulk centralized purchas- ORDER FROM CLOSER PLANT Viking Electronics 80 ing and management know-how, now you TEXAS CRYSTALS can do it the proven PARTS UNLIMITED DEPT. T Walsco Electronics 83 1000 Crystal Drive Division of WAY. FORT MYERS, FLORDA Windsor Electronics, Inc.... 95 Phone 813 WE 6-2109 Application for a franchise should in- Winegard Company 68-69 clude business qualifications as men- AND 4117 W. Jefferson Blvd. Workman Electronic Products, Inc 100 tioned above and address to: Mr. H. LOS ANGELES, CALIF. Shlafer, Parts Unlimited, Inc., 1 State Phone 213-731-2258 Xcelite, Inc. 83 St., Bloomfield, N. J. Zenith Sales Corporation 2nd Cover ... for more details circle 65 on postcard ... for more details circle 47 on postcard 100 ELECTRONIC TECHNICIAN nowith youror Sylvania Distributor a er is too small Authorized He's geared to supply any industrial and commercial Next time you need tubes, call your tube in any quantity, large or small. He's a specialist Sylvania Distributor. You'll find him knowledgeable, in fast service, too. He likes the big orders (who helpful, and ready to serve you. doesn't!), but the small ones get the same prompt Electronic Tube Division, Sylvania Electronic attention. Same -day delivery, wherever possible. Components Group. IA SYLVANSUBSIDIARY OF GENERALTELEPHONE & ELECTRONICS OJT& DEVICES NEW CAPABILITIES IN: ELECTRONIC TUBES SEMICONDUCTORS MICROWAVE DEVICES SPECIAL COMPONENTS DISPLAY Your black and white skills are not enough for Color TV

WHAT THE RCA COLOR TV You need this book PICT -O -GUIDE GIVES YOU: to help you cash In COLOR TV Color Fundamentals Troubleshooting Receiver Set -Up Functions of the on Collor TV business PICT-O -GUIDE Color Set Controls How to Use Color Test Equipment

Troubleshooting Color and Black and White Sections of Receiver

Servicing and NEW RCA COLOR TV TROUBLESHOOTING Alignment PICT-O -GUIDE, 1A1389 Techniques

You're missing more and more chances for profit if you're not in ...and much, much color TV service. There are 3 million color sets in use now...and more. 150 pages. the total should be at least 5 million by the end of the year. This book should more than pay tor The new, completely revised RCA Color TV Pict -O -Guide, with its itself the first time many color photos and illustrated step-by-step instructions makes you use it. it possible for you to recognize and understand the visible symp- THROUGH toms of troubles and maladjustments in ORDER color receivers. Use the YOUR LOCAL Pict -O -Guide whenever you work on a color set. L AUTHORIZED RCA TUBE DISTRIBUTOR RCA ELECTRONIC COMPONENTS AND DEVICES, HARRISON, N.J. For a complete course in the principles and practices of color TV you will find the 8 lesson Color TV Home Study Course by RCA Institutes, 1A1325, invaluable.)

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