Circuit Digests

E. Circuit Digests

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The televisiontehniciein becomes MR.B\G when the TV set goesaad

February 1954 ofALLFixed Composition Resistors byalmost

*Not Claims! Not Predictions! But PlainFacts! Unbiased, authoritative, independent surveys (made regularly since 1930) show IRC BT RESISTORS to be the Service Technicians' choice by a continually increasing margin. Today, BT RESISTORS are preferred over the total of all other brands combined!

Ask for IRC BT's Most Service Technicians Do !

INTERNATIONAL RESISTANCE COMPANY 425 N. Broad Street, Philadelphia 8, Pa. (Avon* &taut Sof -Ann, In Canada: International Resistance Co., Ltd., Toronto, Licensee TECHNICIAN* Circuit Digests TELEVISION ELECTRONIC RADIO AUDIO SERVICE

M. CLEMENTS 0. H. CALDWELL FEBRUARY, 1954 a Publisher Editorial Director SOL HELLER, Managing Editor SIDNEY C.SILVER, Associate Editor Problems Ahead, Outlook Good 21 ANN O'ROURKE, Assistant Editor J.L. STOUTENB'JRGH, Consulting Editor "Tuning in the Picture" 22 CHARLES F.)REYER, Art Director ELMER KETTERER, Circuit -Digest Production More About Color TV Fundamentals Peter Orne & Sol Heller 24 GEORGE PUGLICI, Circuit Diagrams Servicing AC -DC Radios M. G. Goldberg 27

Hi Fi Guide to Pickup Arms and Cartridges Harry Mileaf 28

BUSINESS DEPARTMENT What's Wrong with Carbon Tet? . Harry E. Shulman & Murray Jelling31 M. H. NEWTON, Business Manager Philip Thier 32 H. A. REED, Genera: Sales Manager Troubleshooting Drift in Television Receivers DIXON SCOTT, District Manager Cyrus Glickstein 35 LEE GRAVES, District Manager Eliminating Tweet Interference CHARLES S. ROEVER, District Manager N. McALLISTER, Asst. Business Manager Modern Russian TV Receiver 36 MARTHA USDIN, Production Manager KATHLEEN CAFARO, Reader Service Rx for Ailing CRTs 38 WARREN S. BROWN, Circulation Manager M. GROENING, Asst. Circulation Manager New Components 45 JOHN J. BORGHI, Controller W. W. SWIGERT, Credit Manager Audio and Hi-Fi Items 47

480 Lexington Ave., New York 17, N. 1. Telephone Plaza 9-7880 Technician's Lighter Side 48 S. M. GASKINS, Western Manager 51 JOHN D. LUPTON, District Manager Keep Your Eyes on Profits! 201 N. Wells St., Chicago 6,III. Telephone RAndolph 6-9225 Manufacturer's Changes in TV Sets 58 CHRIS DUNKLE & ASSOCIATES California Representative Circuit Digest Cumulative Index 69 3257 W. 6th Street, Los Angeles 5, Calif. Telephone DUnkirk 7-6149 1355 Market Street, San Francisco Telephone Klondike 2-2311,Ext. 579 *CIRCUIT DIGESTS (See pages following p. 72) ADMIRAL: Chassis 20A2, 20A2Z, 20D2 GENERAL ELECTRIC: "EE" Chassis CIRCULATION MAGNAVOX: Chassis 108A Series RAYTHEON: Chassis 21T11 50,000 WESTINGHOUSE: Chassis V-2250-1 -servingtheindustry'slargest groupof servicetechnicians,service managers and installation specialists. DEPARTMENTS

Letters to the Editors 14 Service Ass'n. Reports 53 TECHNICIAN, Feb-uary 1954, Vol. 59,No.2. Color Shorts 40 Calendar of Coming Events 53 50 cents a copy. Published monthly by Caldwell - 41 "Tough Dog" 54 Clements,Inc.,PublicationOffice,Emmett St.. Shop Hints Bristol,Conn. Eoitorial,Advertisingand Ex- New Products 42 Mfrs. Catalogs & Bulletins 60 ecutiveOffices,480LexingtonAve.,New York New Books 63 17, N. Y. Entered as second class matter at the PostOfficeatBristol,Conn..Nov.4,1953, under the actof March 3, 1879. M. Clements, President;M.H.Newton, AssistanttoPresi- dent; JohnJ.Borghl, Vice President and Sec- CALDWELL-CLEMENTS, INC. retary; Marguerite B. Clements, Treasurer. PublicationOffice,Bristol,Conn. Subscriptionrates:UnitedStatesandCanada, Editorial/Business Offices 480 Lexington Ave., New York 17, N. Y., Tel. Plaza 9.7880 $4.00 for one year; $6.00 for two years; $8.00 for three years. Pan-American and Foreign Publishers also of MART and TELE-TECH & ELECTRONIC INDUSTRIES countries: $7.00 for one year; $10.00 for two *Reg. U. 5. Patent Office years; $14 forthreeyears.PrintedInU.S.A.

Copyrightby Caldwell -Clements,Inc.. 1954 Merit devotes their undivided attention to service equirements for transformers and coils. THERE is n o competition for the time and e ffort of Merit engineers and production, whose sole responsibi- lity is to design and produce what the service field wants and needs when it is needed

Merit --exclusively for service.

4 POINT 2Merit actively aids in irlf service. Merit transformers and yokes re- 0%%opt." tain actual operating characteristics of the wasisfoRmE

Street Clock original components 4427North but design improvements simplify replacement installation. Merit installation instructions are more complete than any others available.

Merit's is the most complete replacement catalog and the Merit replacement guide is ahead of service requirements.

Merit transformers are tape marked* for quick positive identification.

Find Merit's complete line listed in John Rider's Tek-File and Howard Sam's Photofacts and Counter Facts.

*originated by Merit.

PROGRAM air 4 POINT PROGRAM 3It is the Merit cy to simplify Service. erit has proved is possible 11 for one transformer to serve a multiple purpose -- that is replace more than one particular unit without sacrific- ing the essential operating effi- ciency of any of the various original components. Exact replacements are included in the Merit line only when substi- tution would complicate replacement labor. A stock of Merit replacements is always live there are no dust -catchers in the Merit line.

4 POINT. PROGRAM x 4 POINT P mmumime Chicago,fir, Hollywood,2 Hollywood. 3 modern plants prove Merit means: Servicene

Wherever the customer is located there is a Verit plant dedicated to turning out service requirements fast for his area.

The whole country is Merit's backyard and all customers are preferred.

ZOGRAM 011111' 4 P01 PROGRAWI HIGH GAIN

Admiral BOW TIE LOW Lowest cost ever for a quality UHF antenna. Gets excellent reception in good signal areas on any of the 70 UHF channels. Each antenna furnished with stacking bar. Mastmountingbrackets included. Mast not included. No. AN65A-Deluxe-Shipped completely assembled. Suggested list price $5.95 COST No. AN65B-Standard-Similar to above, smaller reflector screen. Shipped knocked -down. Sug.list price.. $3.95

Admiral You'll make an extra profit on every installation using these high gain UHF CORNER REFLECTOR antennas. Ask your Admiral distributor Recommended for troublesome locations where about the extra large discounts from the ghosts, reflections and interference are encountered. list prices quoted here. High gain, 14db. Front to back ratio 15 to 1. Assembled, ready to put up. Mast mounting You'll be giving your customer extra bracket included. Mast not included. value, too! All these antennas are finest quality.. No. ANS6A-One bracket mounting. . made with aircraft aluminum Suggested antenna elements and vibration -proof re- list price 11.25 flectors. "A -frame" insulators provide No. AN56B-Same asabove, frontmount- plenty of free air space around elements. ing. Suggested The units have high mechanical strength list price 11.25 and low resistance. They are double plated for extra resistance to weathering... INDOOR UHF ANTENNAS first zinc plated, then dipped in zinc dichromate which gives them a beautiful gold finish. These antennas can be easily Admiral Super fastened to existing masts and towers. Recommended for troublesome loca- Order by part number from your Admiral tions. Exceptionally high gain ... over distributor. 7 db.... excellent ghost suppression. Only 12 inches wide. Weighted and Ask your Admiral distributor for feltpadded base. FREE CATALOG Admiral Target with complete line of Admiral Smartly styledin rose -goldcolored TV antennas and accessories anodized aluminum with mahogany No. 94A10-6- phenolic base. Stands only 10 inches No. 94A10-7 - Complete with lead-in. high. Base is weighted and felt padded Complete with lead-in. Admiral Corporation suggested ... can be placed on top of receiver Suggested $495 Accessories and Equipment Division, list price..92.95 list price. ... picks up all UHF channels. Chicago 47, Illinois

6 TECHNICIAN February, 1954 Ask your TM DISTRIBUTOR how you can get the time and money saving newRAYTHEON BROW -CITE

Here's another sensational Raytheon first. It's a Here's why Service Dealers from coast to coast are hailing the RAYTHEON BROW-LITE: different kind of flashlight that sheds a new FREES BOTH HANDS - work is easier, faster light on Radio -TV servicing - makes it faster, DIRECTS LIGHT AUTOMATICALLY-you seewhat easier, more profitable. you look at in a clear, bright light

.0AEY ',2 USES STANDARD PARTS - 1V2 volt penlite batter- c. ies and 3 volt penlite bulb RAYTHEON BROW-LITES ANYONE CAN USE IT - fits easily above glasses areavailablethroughyour e EASY TO CARRY - folds compactly to packet size Raytheon Tube Distributor. Ask 40 REPLACES FLASHLIGHTS - easier, safer to use him how to get a supply for you and your men. O DURABLE - made of rugged plastic

AYTHMEON,

Receiving Tube Division excellence in elecitzknics Newton, M3hicago, Ill., Atlanta, Ga., Los Angeles, Cal. RECEIVING AND PICTURE TUBES RELIABLE SUBMINIATURE AND MINIATURE TUBES SEMICONDUCTOR DIODES AND TRANSISTORS NUCLEONIC TUBES MICCOVIIINE TUBES

TECHNICIAN February, 1954 the newest addttton\

.®

1p)

TR-4...tLe de -luxe HEAVY DUTY rot3r complete with modern design meter control dial cabinet, .sing 4 wire cable 53..95 // CORNELL-DUBILIER SOUTH PLAINFIELD, NEW JERSEY to the family of C*D*R Rotors

the ultimate in heavy duty Rotors incorporating all the fine features that have made the TR-2 outstanding plus these fine features:

* Handsome Meter Dial Cabinet * Uses 4 Wire Cable

TR-12 ...a special combina- TR-2....the Heavy -Duty TR-11 ...the all-purpose rotor tion value consisting of complete rotor, complete with "Compass rotor, including thrust bearing ... with handsome modern design handsome modern design cabinet Control" cabinet having illumi- cabinet with meter control dial, with meter control dial, 4 wire cable nated "perfect 'pattern" dial ... uses4wire cable 47.95 49.95

THERADIARTCORPORATION CLEVELAND 13, OHIO over/00/000 already installed! model325-4

model 325

CHANNEL MASTER'S fabulous CFIAMPION* the world's most powerful all -channel VHF antenna -OUT -PERFORMS AND OUT -SELLS THEM ALL! '°°° 1400111/1111 Never before in the history of television has an antenna received such an overwhelming reception. Channel Master's CHAMPION - in a few short months - has rocketed to the top as the nation's most -wanted, best-selling, best -performing VHF antenna! model 325-2 CHAMPIONSHIP Performance: Only the CHAMPION has the unique new "Tri-Pole", a triple -powered dipole syr-em in which the Low Band dipole also functions as three dipoles Ilarlsental Polar tied together, in phase, on the High Band. Pattern pole eloom moat reborn dipole (Relative Voltage) All -aluminum. Assembles faster than a 5 -element Yagil 33O Pt The CHAMPION is another greet contribution of the Channel Master Antenna Development Laboratories.

CHAMPIONSHIP Promotion: The CHAMPION is the artenna 1 1:141 America knows best! I PO 100 I. Publicized in leading magazines Outstanding dealer . Eft Cooperative Advertising Program! Free newspaper mats, window streamers and TV film commercials! THE STACKED CHAMPION PROVIDES: 11-13 DB High Band gain Ws... 61/2-71/2 DB Low Band gain THE STACKED Model Ho. List Price 325 Single Bay $20.83 CHAMPION OUT -PERFORMS 325-2 2 -Bay $42.36 or this 325-4 4 -Bay $88.89 this ... Separate Stacking 14 325-3 I2 -Say Harness $ 2.08 325-5 4 -Bay Ha, $ 6.17

CHANNEL MASTER CORP. IIIIN 9 i t t I,e.r. WORLD'S LARGEST MANUFACTURER OF TELEVISION ANTENNAS 'pot. pending TIE SEPARATE ANTENNAS TO ONLY ONE TRANSMISSION LINE

CHANNEL MASTERinter -action filters

Only Channel Master VHF only VHF -UHF VHF -UHF filters are 01/1/ TENNA-TIE ULTRA -TIE TRIPLE -TIE permanently sealed in a block of moisture -proof, model model model high melting -point no. no. no. electrical wax, 9033-A 9034 9035 locked in an attractive Ties together all three TV styrene case. Use with reception bands: 1. Low Band VHF leads of any length! JOINS - separate VHF and 2. High Band VHF New, specially designed UHF antennas for use with Single lead 3. All UHF High and Lew Passfilters a single lead. No switching entiely eliminate the need High and Low Pass filters for critical lead lengths! This SEPARATES - VHF and UHF enable the Triple -Tie to signals at the set or con- adapt all Hi -La VHF instal- No signal loss new, extremely effective cir- lationsto UHF - quickly cuit makes the TENNA-TIE verter where separate ter- and effectively. "Free -Space" No inter -action, the most effectivefilter of minals are provided. forperfectall- weather UHF reception. effective isolation. its type now available. "Free -space" terminals. - only $3.50 new low price- $3.75 new low price- $4.86

THE ANTENNA IN CUM TELEVISION

by Harold Harris,Vice President, Sales and Engineering Now that color telecasting is a reality, we will see There are also indications an ever-increasing flow of color sets to the consumer. that fringe area color recep- Although much is being said and written on the sub- tion may be more critical. ject of color sets, many unanswered questions remain This may necessitate the use of fringe area antennas about the role of the television receiving antenna in in areas closer to the TV station. color television. In the nation's most advanced television research Will present antennas work on color? laboratory, Channel Master antennas have always been designed for full band width and minimum variation Will a special antenna be needed? in gain on any one channel. The results of thorough laboratory and field tests For this reason, every Channel Master antenna which made by engineers of the Channel Master Antenna you have installed in the past, as well as the ones you Development Laboratories show thatpracticallyall installtoday,willprovidereception of outstanding present TV antenna types will perform satisfactorily on quality when color TV comes to your area. color. Gain variations as high as 3 DB across one channel can be tolerated. When this figure is exceeded Channel Master antennas were the blurring or smearing of the picture may occur. Although antennas selected for the tests which there are certain antennas on the market which do led to the F.C.C.'s approval of the have excessive gain variation, thisis not the case of National Television Standards Com- the vast majority of present installations. mittee color system.

mor.rorerrmorr r--r.o.

r igh011se !MAMMA 'ROW,

Get this ONE DOLLAR book FREEwithyour next 25 -TUBE PURCHASE This newest, most helpful book on UHF the biggest profit opportunity since television conversions is yours free when you buy 25 came alive. RELIATRON receiving tubes or one picture Get this dollar value for no extra charge with tube from your Westinghouse Distributor. your next order of 25 tubes! See your nearest This vital handbook covers conversion data, Westinghouse RELIATRON Tube Distributor tuners and converters, antenna installations, for your copy of this new "how to do it" book channel frequency charts, station coverage, and that will build your profits. many other necessary, conveniently arranged facts you will need. There's a gold mine in UHF conversions. And 0 w this book will help you make the most out of

U3024 IF IT'S alifFil8ill. ... See Westinghouse Tube Listings in 1954 Photof act Folders. YOU CAN8ESURE RELIATRON TUBES

WESTINGHOUSE ELECTRIC CORPORATION, ELECTRONIC TUBE DIVISION, ELMIRA, N.Y.

12 TECHNICIAN February, 1954 /ILL ea.t.

N11> PROVED from coast to coast In every UHF area, Mallory Converters bring clear, trouble-fr2e all -channel reception to thousands and thousands of families. ?lake sure your customers get this PROVED PERFORMANCE. 31:11101-y UHF Converter tt

Prove to yourself that the MaLory Converter can be a profit -maker for yoa. Ask your Mallory distributor for details on the Mallory 88 Converter.

It's a fast -seller ... easy to install ... and performance is outstanding.

,-44-

P.R. MALLORYftCO in, MALLORY CAPACITORS CONTROLS VIBRATORS SWITCHES RESISTORS RECTIFIERS POWER SUPPLIES FILTERS MERCURY BATTERIES APPROVED PRECISION PRODUCTS P. R. MALLORY & CO.Inc., INDIANAPOLIS 6, INDIANA

'NY - 4$07.4,0 - A, WHY IT'S BETTER BUSINESS TO REPLACE WITH LETTERS To the Editors 700-atea etveat'Pedero Author In Error, He Says EDITORS, TECHNICIAN: We would like to call your attention to considerable misinformation which appeared in the article V.H.F. Antenna IN APPROXIMATELY 75 percent of all cases, the original Installation Problems, in your December crystal pickup cartridge for which you are supplying the issue. (1) The author describes at length replacement will be an ASTATIC! The record player "oscillating lines." It is well known that manufacturer's highly skilled engineers have carefully two conditions are necessary for sus- tained oscillation-a feed -back path and selected each Astatic Cartridge because . .. down to the energy amplification. Since there is no last detail.. .its performance characteristics match the amplification of energy in an antenna or requirements of the particular player or changer. Thus, its transmission line, oscillation cannot for finest results, the serviceman replacing the cartridge exist outside of the television set. One should not confuse the "gain" of an an- must again match these requirements. AND ONLY THE tenna with amplification, or the reflec- PRECISION -BUILT, RECOMMENDED ASTATIC REPLACE- tions in a transmission line due to mis- MENT CARTRIDGE WILL DO IT. And, despite quality re- match with oscillation. In Channel Mas- ter's wide experience with TV antenna sults, cost is almost invariably lower. installation problems, we have never One way or another, a substitute cartridge is bound to heard of "oscillating lines." fall down.It is not sound business to stake your reputa- (2) In the second paragraph, the author advocates the use of an open-ended tion on such substitutions. Beware particularly of claims stub across the antenna. The stub is cut that ALL cartridge replacement needs can be filled by to an effective quarter -wave length at six or eight magic models. Actually, it takes an absolute the channel frequency which is to be improved. It is well known that a quar- minimum of 24 different cartridge models to meet all of ter -wave length open-ended stubis today's requirements. The far-sighted jobber or dealer, almost exactly equivalent to a short- knowing that what is good for the record -playing public circuit. It is obvious, then, that placing this stub across the antenna as described is good for him, sees to it that the kind of cartridge origin- will almost completely eliminate recep- ally intended is used on all replacements. Usually, too, tion for the channel oneistrying to he MAKES DOUBLY SURE OF BEST RESULTS BY RELY- improve. (3) In the third paragraph, the author ING ON ASTATIC CRYSTAL CARTRIDGES. suggests using an attenuating pad to eliminate "ghosts." When "ghosts" are NEW STEEL STORAGE CABINET AND DISPENSER due to reflections in the transmission FOR ASTATIC CRYSTAL CARTRIDGES line, due to mismatch at its ends, the use of a pad will help. However, in the THERE ARE ADVANTAGES for case of "ghosts" due to multipath recep- everyone because jobbers dispense tion, the ratio of the direct signal to the Astatic Crystal Cartridges from this reflected signal is not changed by a pad. handsome, rugged steel cabinet. No one - dealer, serviceman or record Therefore a pad will not help at all to player owner - ever gets an Astatic reduce "ghosts" due to multipath recep- Cartridge which has grown old from tion. Furthermore, the formula given in being accidently shunted back and this paragraph will not give the straight forth on the shelf. This can't happen line distance to the reflecting obstacle; to Astatic Cartridges because new it will give the difference in total path stock is put in the cabinet by feed- lengths of the direct and reflected sig- ing into the top of each bin . . . nals. and the cabinet dispenses the oldest We hope this clears up the errors in cartridgefirst,from the bottomof the bin.To make sure that every- your otherwise excellent periodical. one enjoys these advantages, the Jur.ms GREEN cabinets are given toAstatic Job- Antenna Laboratory bersentirelyfreeofcharge, and Channel Master Corporation without a single string attached or special purchase to be made. Attractively Ellenville, New York finished in light grey Hammerlin, this truly fine cabinet keeps all Astatic Cart- ridges together and permits taking accurate inventory in one glance. Itis Free Tube Checking Again designed to stand solidly on the counter, on the shelf, hang on the wall, or even stack securely when two or more are used. Included is a handy Rolla - EDITORS, TECHNICIAN: fax cartridge replacement chart, which attaches to the top of the cabinet and I have been an ardent reader of your works like a miniature window blind. Note that the bottom cartridge in each magazine and still regard it as one of bin always protrudes, for quick, easy grasping. the top magazines in our profession. In the November edition, I read several articles on charging for tube checking. EXPORT REPRESENTATIVE I realize that this is a pro and con af- fair, but the following isone tech- 401 Broadway, New York, N. Y. AsmnouricCORPORATION nician's view point: Cable Address: ASTATIC, New York One of the most imperative qualities (Continued on page 18)

14 TECHNICIAN February, 1954 Vest? Now... only *149 er Price the popular RCA WO -SSA

featuring... Voltage -Measuring Facilities "Plus" and "Minus" Sync High -Input Resistance If Low -Input Capacitance

Check these "extra" features Direct -coupled vertical amplifier 5 Cathode-ray tube with magnetic shield 60 -cycle sweep with wide-angle phasing control Frequency -compensated attenuators "Voltmeter -type" vertical attenuator The WO -88A has built-in voltage cali- megohms! Because many TV circuits "Voltmeter -scale" type graph screen brating facilities which permit simul- are extremely sensitive to resistive load- 1 -volt peak -to -peak calibrating voltage taneous waveshape display and peak -to - ing, normal circuit operation may be 'Scope is completely stable-even at maxi- peak voltage measurements. Frequently, seriously disrupted by loading of the mum sensitivity of 25 millivolt -per -inch the shape of the TV waveform under average 'scope. With the low -capacitance Quick "recovery" time, freedom from line observation will be correct but its ampli- probe, however, loading problems are "bounce" tude will be low and, consequently, cause minimized. Check this feature on the "88"! Completely shielded input cable eliminates improper operation. Therefore, a TV In addition, the low -capacitance probe hum and noise pickup 'scope is complete only if it can measure supplied with the WO -88A decreases the the peak -to -peak voltage of the displayed over-all input capacitance to less than Specifications - waveform. Check this feature on the "88"! 10 uuf! Excessive capacitance loading Deflection Sensitivity:(verticalampli- On the WO -88A, sync polarity may can cause the horizontal oscillator to fier) 25 rms millivolts or better per inch. be reversed instantly by simply clicking change frequency or stop oscillating. Vertical -Amplifier Frequency Response: a front -panel switch. This feature is When the WO -88A is connected, the low Flat from dc to 100 Kc; within -3 db at important because TV pulses may be over-all input capacitance leaves receiver 500 Kc; within -10 db at 1 Mc. either positive or negative, depending operation essentially unaffected. Check Input Resistance and Capacitance: 10 this feature on the "88"! megohms and 9.5 uuf with WG-216B Low - upon where the 'scope is connected. To Capacitance Probe. avoid waveshape "jitter" or distortion, Sweep -Circuit Frequency (four ranges) : use a 'scope which will "lock in" readily Get full details today from 15 cps to 30 Kc. on all types of TV waveforms. Check your RCA Distributor or clip Square -Wave Response: Negligibletilt this feature on the "88"! coupon and mail to: and overshoot. When you use the low -capacitance Average Rise Time (Vert. Amp.): 0.5 probe supplied with the WO -88A, the microsec. the over-all input resistance is raised to 10 eel\III's Power Supply:105-125 volts, 50-60 cycles. 1 or:gkai I0.2"SO°1 koV'e Size 133i' high, 9' wide, 16Adeep. I 0.2"IV. f6,0X v.,e.:74 Weight only 25 lbs. (net). ,o0 'itC,VA011.1?' fie ,cole*

RAD/0CORPORATION of AMERICA TEST EQUIPMENT HARRISON. N. J.

TECHNICIAN February, 1954 15 Arthur Godfrey, famous CBS -TV star

WITH CBS-HYTRON WITH CBS-HYTRON WITH CBS-HYTRON MIRROR -BACK SCREEN BLUE -WHITE SCREEN SMALL- SPOT GUN GLASS FACE PLATE SCREEN - MIRROR SACK

No,, light

output from sc. n MAGNIFIED CROSS-SECTION Rorrforcing light

by Mirror -Bock

Mirror -Back (aluminized) screen mirrors Ever notice how a shirt laundered with Smaller the spot produced by electron all the light output to the viewer. Offers: bluing appears whiter? With the CBS- beam, sharper the picture. New lens Brighter pictures. Greater contrast. Better Hytron Blue -White screen, whites are focusing system of CBS-Hytron Small - resolution. Reduced strain on other com- whiter;blacks,blacker. Expanded Spot Gun reduces spot size 30 per cent. ponents. Full effective anode potential. gray scale gives noticeably sharper pic- Prove it.Replace with a new CBS- Prevention of cross -burns. And longer life. tures in fringe areas. No wonder CBS- Hytron Small -Spot tube. See, yourself, For greater customer satisfaction ... more Hytron's original Blue -White screen the superior resolution. Profit more. profit, replace with original CBS-Hytron has become the universally preferred Combine all three: CBS-Hytron Mirror - Mirror -Back tubes. Many types now standard. Your customers, too, will Back ... Blue -White Screen ... Small - available. prefer Blue -White screens. Spot Gun. Get and give that better - than -new -set thrill !

LOOK TO CBS-HYTRON FOR COLOR, TOO! New CBS-Colortron stresses simplicity. Offers many advantages: Simpler construction. Fool -proof assembly. Lower cost. Lighter weight. Adaptability to mass production in large sizes. Improved contrast. Simplified focusing... circuitry ... adjustment. Re- sistance to overload. Greater stability. All stemming from unique spherical mask and face plate. You'll appreciate these advantages when you start servicing color TV.

NEW ...FREECBS-COLORTRON DATA FREE CATALOG For a look into the future, get complete advance data on

CBS-HYTRON the new, revolutionary CBS-Colortron: Construction... operation ... application ... installation and adjustment BUSINESS BUILDERS ... electrical and mechanical data. FREE ... from your CBS-Hytron distributor ... or direct. Describes all CBS-Hytron BusinessBuilders to date: CertifiedQuality Service tags, streamers, decals, illumi- nated and flange signs, clocks, postal cards, and ad mats. The famous CBS-Hytron service tools. Technical literature. Price lists. Special offers. Get your Business Builders CBS-HYTRONMain Office: Danvers, Mass. Catalog, PA -37, today ... from your distributor, or direct. YTRO Manufacturers of A Division of Columbia Broadcasting System, Inc. Receiving Tubes Since 1921 A member of the CBS family: CBS Radio CBS Television Columbia Records, Inc. CBS Laboratories CBS -Columbia and CBS-Hytron

RECEIVING TRANSMITTING SPECIAL-PURPOSE TV PICTURE TUBES GERMANIUM DIODES AND TRANSISTORS

16 TECHNICIAN February, 1954 vistoet'

most

Mutteatt you believe in AntennaClaims? Every claim for all -channel antenna perform- 22 ance should be supported by facts, and not Dg "sales talk!' With facts to follow, you guard your reputation for integrity. Facts are what you get from DAVIS ... indisputable proof of performance, furnished by an impartial outside authority : Microwave Engineering Company, of Los Angeles, who are recognized experts on antenna research and testing. Write for all the data which Microwave Engineering has developed on the DAVIS antenna. You'll see performance characteristics which are actually certified ... data you can count on! Remember, it's the picture on the TV set that pays off in customer satisfaction. A DAVIS picture must please you-our antenna is guaranteed to be the best all -channel unit you can buy ... guaranteed to please or your money is refunded by the factory. Send the coupon for facts on the DAVIS antenna. Sold through your electronic distributor ... THE BACKBONE OF YOUR INDUSTRY.

MAIL THIS COUPON TODAY:

DAVIS ELECTRONICS, Box 1247, Burbank, Calif. Gentlemen ...send me the following: Technical data and complete information on the new SUPER -VISION ANTENNA 1:1 Name and address of NEAREST JOBBER

COMPANY NAME

MY NAME

ADDRESS

STATE DAVIS ELECTRONICS P.O. BOX 1247 BURBANK CALIFORNIA _J Factories in; BURBANK, CALIF., CHICAGO, ILL., SILVER SPRINGS, MD.

TECHNICIAN February, 1954 17 (Continued from page 14) in my estimation for a successfultech- nician, is the love of the businessand also not to be too arrogant in helping the average customer. I honestlybe- lieve that this article regarding charging for testing tubes will tend to make some of the servicemen a little too independent, in charging for everything they do for a customer. Thereare things that come up daily in ourpro- fession that have to be handled dis- creetly, such as replacing a male plug on a lamp or fixing a lady's iron. All these little things tend to obtain good will, something that would normally cost you a good sum in advertising. I have been in business for over fifteen years, never made a fortune, but have always been busy and have made a good living. I believe in the old creed, when a customer asks you to do anything you should be honoredthat SCRperformer he asked you, also.. . charge according to the job. I hope that in one of your editorials you will try to educate the newcomers AMONG CONVERTERS in our profession to follow this creed UHF a little. I still think that, with a customer's respect. ..and good work- As an established service -dealer, know the relative manship, a serviceman can charge a merits of all UHF converters. This means more than little more and still be well ahead of the fellow who is arrogant and charges pretty cabinets or glittering generalities or bargain for even a washer or maybe to just prices.It's performance that counts. And Granco's dust off a chassis. GEORGE E. FOGLEMAN superlative performance-the best by test-is based Fogleman Radio & TV Service on these absolute essentials: 1721 Fort Street, S.E. Washington 20, D. C. COAXIAL TUNING:Most efficient UHF tuning system known. Precision -ground metal slug sliding in and out Likes Price Editorial of precision -ground glass tube for mechanical and EDITORS, TECHNICIAN: Your article in the December issue, electrical accuracy. No troublesome noise -producing wiper "Don't Be Afraid to Charge a Good contacts. Highest stability. Provably better UHF reception. Price!" was wonderful. I am conceited enough to say that that has been my orFINE TUNING:No "on -again off -again" tuning with exact feeling and policy. Granco. Fine tuning is simple and positive with high -ratio L. WALTON. single tuning knob. Permits "on the button" tuning without Broadway Radio Service 7 East 19th Avenue need of safecracker's touch! Gary, Indiana

PRESELECTION:Tuning circuits reject unwanted signals Cut -Throat Competition and images-only the desired channel is tuned in. A "must" EDITORS, TECHNICIAN: in areas havingtwo or more channels,UHFor VHF. Granco Ireceive TECHNICIAN magazine preselection means cleaner, sharper, more pleasing every month, and look forward to every pictures. edition, for it has given me so much help. There has opened up a wholesale AMPLIFICATION:Low -loss tuning and associated house in Washington, Pa. They have circuitry, plus high -gain amplification of only the been running ads in all the papers de- tuned -in channel, provides the finest reception in TV. scribing the wholesale prices of all our parts, and at the bottom of these ads they state this-Wholesale toAll.It from your distributor or from us. Compare makes me have a red face when a cus- ask for data Granco UHF converters with all others. Make tomer of mine prices an antenna from me and I tell him the list price for it; your own comparative tests. You're the judge! then he comes right back with the newspaper ad showing me the same antenna at half the cost. Some of the prices are even lower than I can buy for wholesale. What is the solution to GNCO PRODUCTS INC. this problem? 36-17 20th Ave., Long Island City 5, N. Y. LARRY J. Srum. AVAILABLE AT LEADING JOBBERS Stull's Radio & TV Marianna, Penna.

18 TECHNICIAN February, 1954 -ittc, &mat New- INCO® .0z;IS500 UHF ANTENNAS (All Aluminum Construction)

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TECHNICIAN February, 1954 19 Another Outstanding Service SuccessStory...

withSYLVANIA!

From Basement Repair Shop The steady and substantial growth of the Ball Tele- vision and Radio Service, from basement shop to the to prosperous Service Business... large handsome brick building, shown below, is a featuring Sylvania Tubes, Parts tribute to the fair practices and alert policies of the owner, Mr. Ted Ball. and Promotion Programs!

Says Mr. Ball: "My men are as skilled and experienced as any you'll find anywhere, and each is instructed to do the best job possible with the best of parts. .. and that, of course, includes Sylvania Tubes."

Ted Ball is another important Radio -TV Service Manager that appreciates the quality performance, dependability, and the nation-wide high reputation of Sylvania products. Mr. Ball also knows about the business -boostingpower of Sylvania's promotion and display offers. Find out how Sylvania can step up your business. Your friendly Sylvania Distributor is ready and anxious to give you full cooperation. Call him today. SYLVANIA Sylvania Electric Products Inc., 1740 Broadway, New York 19, N. Y

booths repolr efWentRadiotodosi. modern, Shovimg an In Canada: Sylvania Electric (Canada) Ltd., University Bo111elev\s'Ion Tower Bldg. St. Catherine St, Montreal, P. Q. LIGHTING RADIO ELECTRONICS TELEVISION 20 TECHNICIAN February, 1954 TECHNICIAN &Circuit Digests

CALDWELL-CLEMENTS, INC., 480 LEXINGTON AVENUE, NEW YORK 17, N. Y.

Problems Ahead, Outlook Good

As we go into the second month of the new year, we get a clearer picture of what's ahead for the technician during the remaining months. In taking this look ahead we can foresee a phenomenal growth for the service industry, as pointed out in last month's editorial. Color -TV is on the way. Hi-Fi is growing by leaps and bounds, and maintenance of a record number of B & W sets, radios, phonos and recorders spells big business in anybody's language. Year by year servicing revenue will grow in this restless industry which is always bringing out something new, exciting and different to challenge the ingenuity, skill and know-how of the technician. Yes, '54 looks like another buy year for the men who keep the home folk happy, maintaining the equipment so many millions depend upon for daily entertainment, education and enlightenment. '54 Can be a year of greater profits and expansion for the technician -dealer who wisely meets the challenges that lie ahead. But there will be problems which the service department must face.

Tight Money Will Affect Service Operations

Many of such problems will come about as the result of a more or less tough market in retail selling, which is likely to be reflected in tighter money conditions at the service business level. For instance, folk are hanging onto their money for dear life, and this will cause more haggling over service bills. Then, too, the gyps will intensify their efforts to increase their take, and more of them may be operating. Customers may be a little slower in paying bills, and there may be a rise in the number of dead -beats.

Safe Method to Build Profits and Good -Will

All of the foregoing doesn't mean that servieL: revenue will be down. On the contrary, 1954 bids fair to be the biggest year ,,he industry has ever had. But '54 also looks like a year when the service department must watch its financial step every inch of the way. It must guard against accumulating bad accounts, it must fight to sell good, honest service at honest prices, and it must maintain prestige, profits and customer good will. Also, advertising should be kept up or initiated, in this rather slippery period, to retain old business and add new trade. Never was there a time more suited to advertising your service business. The profit -minded technician -dealer needs to sell faith in the country to his customers these days, when all too many self-appointed dispensers of gloom are predicting financial chaos in the midst of the greatest prosperity the nation has ever known. The future of the service business was never brighter, but smart owners and managers realize that '54 isn't a year for coasting or resting on one's laurels. It's a year for hard work, hard-boiled supervision and the will to meet and lick the problems which appear to be in the offing.

TECHNICIAN February, 1954 21 the

GREATEST ERA AHEAD FOR SERVICE BUSI- NESS, and we're not fooling! Never before in the history of this industry has the opportunity for increasingserv- ice volume been so promising. Color TV, ofcourse, leads this opportunity parade, with Hi-Fi following closelyon its heels. By the end of this year, more than 100,000 (perhaps many more) color sets will be in consumers' homes, and their installation and maintenance, while posing many a problem, will be a stimulating (and profitable) challenge to the technician.

AND THIS 100,000 OR MORE COLOR SETS is noth- HIGH UHF CONVERSION FEES in someareas are ing but a trickle preceding the production delugeon the drawing grumbles from set owners and managers of new way, because in 1955 several million color receivers will UHF stations alike. Consumer complaints to the stations in all likelihood be in use by consumers, with total TV state that some servicers ask $75 or more for adjusting or adapting a set to receive a new UHF channel. This sets in homes and public places probably reachinga fig- prac- ure of 40,000,000! tice hurts both the technician and the station, UHF station operators claim. Some directors of new UHF stations are cooperating with service dealers and technicians in HI-FI IS ON THE WAY, TOO, and it's moving fast to- planning inexpensive conversion techniques, and in ward the high places, presenting hundreds of opportunity bringing this information to the public. Checking with the angles for the service industry to capitalizeon. Service UHF station in your area re its recommendations as to andinstallationwillinvolve components, complete the best and cheapest technique would be a good idea instruments, phonos, tape recorders, phono needles and before going ahead with conversions. a wide variety of accessories. The sale of custom -installed Hi-Fi units alone may well ring up a total of $220,000,000 TRENDS IN THE OFFING as we go into the second this year. month of the new year: More and more customers will ask YOU about Color -TV, and for the sake of good public relationship you must have intelligent answerson the tip of your tongue....Plenty will ask about Hi-Fi, too, and while this subject is a bit complicated for the layman

to understand, try to explain in simple language.... '54 promises to be a year of stiffer competition for the service dollar. TECHNICIAN editors predict a slight increase in the number of servicing outlets. SEVERAL DEPARTMENT STORE service set-ups have been making headway in, some of the large cities, gaining business chiefly through reputation, and solici- tation of large customer lists. Trend could spread this "How many volts you figure that was, Perkins?" year,offeringtheindependentssomeveryreal competition. ON THE BUSINESS FRONT: Repair business fell oi," sharply after Xmas in the metropolitan New Yorkarea MANPOWER SITUATION EASING in some heavy for reasons no one can accurately pinpoint, thoughone industrial centers, but still very tight in New York, parts large service outfit says people are hangingonto their of California and in most of the South. Some suburban money for dear life, and are willing to tolerate poor re- New York shops paying $100 a week to TV servicers with ception until they've recovered from holiday expendi- very little experience. tures. ... Small-town dealers loaded with accounts receivable in many sections of. country had betterget out DIPLOMACY by servicers is becoming more important and collect their dough. Big -city service organizations than ever, field reports say. With the trendaway from carrying only small number of charge accounts, because service contracts toward individually -billed service calls, of C.O.D. policy most insist upon.... Dealer credit situ- set owners are less critical of secondary deterioration in ation has improved in most localities over last Summer, receiver performance. They usually wait for major distributors in large cities report. breakdowns before hollering "Uncle." As a result, more calls than ever involve multiple troubles. Completeover- SOME TECHNICIANS IN CERTAIN UHF AREAS hauls bring squawks over high bills. Repair of major de- are selling plenty of converters by simply demonstrating fect alone raises complaints of incompetent work. Either the units in the home. Where good reception is obtained, way, the technician is left holding the bag. Getting to be such demos result in speedy sales. Converter "price -war" like the radio dads when more than half the sets inuse which broke out in Milwaukee has ended. were in need of repair.

22 TECHNICIAN February, 1954 Picture in every SAME OLD CHASSIS!-The doctorcomplained bit- PIX TUBE OUTLOOK FOR '54. Almost one terly about the $18.75 charge for repairinghis TV set. seven TV sets in use todaywill require a new picture general man- "My TV is certainly not as complicated as ahuman tube in 1954, according to J. Milton Lang, being. I spent six years in college," he said tothe tech- ager of the G -E Tube Department.Market research in- I practiced replacement picture nician, "and two years as an interne before dicates a need for over four million any medicine. But I can't get anyfees like that for my tubes. Over 27 million sets are now in usethroughout the "we have a tube figure rep- work." "In TV," replied the TV technician, country. Lang said the high replacement couple of thousand models to deal with. Every yeareach resents a normal development, with so manysets growing the highest of any manufacturer brings out at least one new model. We've older. The four -million plus figure is got to have a big library of technicalinformation and year to date, and is expected totop the 1953 requirement attend many meetings to keep up to date. But you, by about 50 per cent. Despite the adventof color TV, the additional pic- doctor, still work on the same model you studied in industry should produce about 5,200,000 school."-Sterling Intercom, Houston, Tex. ture tubes for new black -and-white sets, Lang estimated. The need for initial equipmentmonochrome tubes will come in large measurefrom opening up of new market areas, and from continuing consumerdemand for the larger picture sizes and lower pricesof high -quality black -and -white receivers. Langbelieves color picture tubes should make up about two per cent ofthe industry's total CRT output in '54. REMEMBER 'WAY BACK WHEN pre-warTV antennas were of the "pitchfork" type? ...When, during the transmission -line shortage some of youfellows had to use solid -conductor cablewhich came from abroad? of the pres- ...And those days when the predecessors ent dollar -a -call boys charged ahalf a buck?. ..Can you recall, too, the ion"spots" on many pix tubes? the "diathermy -interference" craze? The eraof magnifiers "Must be something wrong with this set ... and filters? all we can get is people." SALES RESISTANCE TO B & W TV, on partof consumers adopting a "waitand see" attitude on color, is in WHEN A TECHNICIAN BUILDSUP A REP AS A for a major assault by manufacturers.Most top set pro- GENIUS in his community,whether he's the owner or the ducers are announcing 21 -in. blackand white sets to sell service manager, he findshimself in a tough spot as the below $200, representing drastic price cuts intheir for- business expands because everybodyand his brother expected to follow. Confiden- wants this particular "wizard" toPERSONALLY service mer lines. Other leaders are can't be done when tial sources say these new lines,streamlined in design for the ailing sets. Naturally, this just low pricing, have been on paper for some time.Seems there's a big volume of work. Bestthing to do in such the industry-or at least part ofit-anticipated B & W situation is to "build up" othergood technicians in the resistance with advent of color, and is allready to meet organization, "selling" them to the customersvia direct - contacts. the challenge. mail, over the phone and in personal YOU MUST HAVE SOMETHING ON THEBALL to HARD-BOILED SIGNS, such as "NotResponsible for stay in business. Motorola's ServiceDep't. calls attention Sets Left After 30 Days," "All WorkStrictly Cash," and to a recent government report thatvividly illustrates the the like, do more harm than good, sincethey antagonize need for good management and goodbusiness control. customers, and don't mean anythinglegally anyway. The report states that only twenty eight concernsout of Better put up some reading, "AllWork Guaranteed," going concerns after five "We Use Finest Parts," "Best TestEquipment," "Our every hundred started were to build years of operation. Thefollowing shows the average trend Technicians Are Highly Skilled Specialists," etc., per hundred business ventures: good -will and inspire confidence in yourservice depart- Year of Operation Failures Remaining ment. 1st 32 68 SOME RANDOM THOUGHTS INTHE FIELD: TV 2nd 18 50 -minded than any 3rd 12 38 antenna makers are more competitive other folk in the business. ...There's been a definite de- 4th 6 32 tubes into shops for 4 28 cline in number of people bringing 5th testing. This activity was at its heightduring the Depres- These statistics deserve your seriousthought. Are you like taking steps to insure that YOU will still be inbusiness sion. ...Even if they can't understand 'em, people five years from now? to get itemized bills for service. 23 TECHNICIAN February, 1954 YELLOW GREEN GREENISH YELLOW YELLOW

YELLOWISH ----ORANGE ,ORANGE PINK REDDISH ORANGE

GREENISH BLUE

(A)

VARYING REDDISH SHADES PURPLE OF GREY PUR P LIS IL/ PURPLE BLUE BLUISH PURPLE WHITE

(G1

Fig. 1 A-The horseshoe comprises all the visible colors; the triangle includesall colors reproducible in color TV. Colors shown in this triangle are recognizable to the eye when they cover large areas. B-When medium -smallareas are viewed, blues and yellows appear gray, and only cyan and orange are clearly distinct. Two areas rather thanone are shown as gray. This is so because yellow and purple-the colors really present in these areas-will look gray if the observer's distance fromthem is great enough. C-The eye cannot distinguish between colors and black -and -white when small objects are viewed; only intensityvariations-referred to as varying shades of gray-are visible. More About Color TV Fundamentals

How the Eye Sees Color. What "Q," "Y" and"1" Signals Are. Sub -carrier Modulation Explained

BY PETER ORNE TV Color System), and will be con- tions may be summed up as follows: AND sideredingreaterdetailinthis The eye cannot seecolor-i.e., SOL HELLER piece. MANAGING EDITOR, TECHNICIAN distinguish between colors or black- The less information that has to and-white-whentheobjectin- be transmitted in addition to the spected is very small (see Fig. 1C). Last month, we tried to clarify luminance information(luminance The eye has "three -color" vision, on how room was found in the black- refers to the color signal component the other hand, for large objects and -white spectrum for color sig- that corresponds to the black -and- (Fig.1A)."Three -colorvision" nals. In this month's article, we will white video signal) the less chance reviewthe means that we can, by mixing lights nextproblemsur- there will be of interaction taking ofthreecolorsintheproper mounted by NTSC researchers- place among the different signals amount, cause the eye to see prac- i.e., their determination of the mini- sent out. In order to determine the tically any color. This duplication is mum information required to obtain minimum bandwidths to which color called color matching. asatisfactorycolorpicture.The signals could be reduced, many in- There are many ways of obtain- problem was briefly discussedin vestigations' were made into how ing a color match. Almost any three the Oct. '53 issue of TECHNICIAN well the eye sees small areas of widely -separatedcolors may be (Serviceman's Analysis of the New color. The result of these investiga- used (as we shall see later). In the 24 TECHNICIAN February, 1954 color picture tube, red, green and colors in Fig.1 are grouped in a reference colors are used as axes blue lights (given off by phosphors horse -shoe form. The theory behind (vertical andhorizontalaxes,of on the screen) are employed for this this may be summarized as follows: course) any color visible to the eye purpose. Any color can be reproduced by may be plotted as a point on this How about cases that fall in be- mixing three colors together. The diagram. The height of the point (or tween the extremes of no color and three colors used are known as the its distance above the X axis) indi- three -colorvision-i.e.,thein- primariesof the system. The only cates the amount of one reference stances when medium -small objects restriction regarding the choice of color present; the distance of the are being viewed? What the aver- colors is that a primary color must point from the Y axis indicates how age person sees in these instances not be reproducible by any mixture much there is of the other reference may be reproduced by the mixture of the other two primaries. color. of two colors (see Fig. 1B). Some When such a diagram is made, it color-blind people, incidentally, see Color Designation Systems is found that visible colors fall into both large and medium-sized ob- an area- that looks like an inverted jects in this way. Visible colors can be represented horse -shoe. The nearer we come to In viewing medium -small objects, in different ways. Most readers are the center of the horse -shoe, the most of us readily differentiate be- probably familiar with the fact that less saturated the colors get-i.e., tween cyan (a bluish green) and or- the whiter they get. The area at the colors can be designated by their center is what most people consider ange. Blues and greens, however, wavelength.Scientistsconcerned look like cyan, and reds and yellows with the study of color have found white. look like orange. We can experience it convenient to use another method this effect if we try to match a sin- of representing visible colors. They Subjective Aspects of Color gle fine strand of colored thread to (arbitrarily)choosethreecolors a correspondingly -colored spool of thataresupersaturated-i.e., un- Color is subjective-that is, dif- thread. mixed with white-and define any ferent people give different names Itappears,therefore,that we other color by giving the amount of to the same shade of color. In addi- need three components of informa- each supersaturated color necessary tion,colorslookdifferent when tion to get proper coloring for large to reproduce it. their surrounding color is changed. areas; two pieces of information are The supersaturated or reference White is a wide area (in Fig. 1) be- required to get satisfactory color on colors are non-existent in nature cause desaturated shadesof any "medium -small"areas;weonly and cannot be seen by the eye. color (i.e., color mixed with white) need to know the luminance for They provide arbitrarystandards will look white if looked at for some very small areas. for comparing colors. time without comparison. This is the One of the reference colors is so reason, incidentally, that the shade "0","Y" and "I"Signals chosen that its amount affects only of white used on a black -and -white the brightness (not the hue or satu- crt screen turned out to be much The way we see small detail, in ration) of the color to be defined. less important than originally ex- monochrome thatis, and the fact The other two colors are capable of pected; only when a number of b & that we want a compatible system, representingany definitecolor w sets are put next to each other makes it necessary that one of the (except with respect to brightness). does the difference in screen white- components be the luminance or The system is essentially the same ness become apparent. "Y" signal. From the fact that we as the one used in color TV, in A final note on the horse -shoe can distinguish cyan and orange which two signals-"Q" and "I"- patterns of Fig. 1: There are actu- bestinmedium -smallareas,it determine the color, while the third ally no sharp divisions between col- would be an advantage to choose as one-"Y"-reports on its brightness. ors, such as those that seem to be one of the other components of in- When the two supersaturated or present in these sketches. Different formation a signal that distinguishes between these colors. This signal is Fig. 2-Bandpass requirements for "0"Y" and "I" signal components. called the "I" signal. For large areas, where the eye can distinguish betweenallcolors, another pieceof intelligence must be added which is called the "Q" signal. This signal distinguishes between green and purple. If the information present in the "I," "Q" and "Y" signalsis combined, any visible color can be effectively reproduced, thus permitting "three - color" viewing. Summing up:"Y" isthe luminance information; it is transmitted for the full 4 mc. "I" is the information that can tell cyan from orange, and is transmitted to 1.5 mc. "Q" is the information that, in conjunction with the "I" and "Y" signals, pro- videsthethreecomponentsfor "three -color" vision; it is transmitted for only .5 mc (see Fig. 21. Readers may wonder why the

TECHNICIAN February, 1954 25 With the problem of how much (or quadrature-shifted). The second color information to transmit sur- glass section, which makes an angle e mounted, the next difficultythat of 90° with the first one, may be arises is how to transmit two differ- compared to the phase -shifted color READ ent pieces of color information, "Q" subcarrier. "IS and "I," on one subcarrier. If we If the exact phase of the carrier could use two different subcarriers, when the signal was modulated onto /1/ "Q" could be modulated on one and it is known, the modulation can be "I" on the other. This is effectively removed or detected (just as the done, but the two carriers are at the glass sections can be read,if we same frequency.Sincethis may know the angle to read them by). sound like double talk,let'ssee This type of detection is known as whether we can clear it up. synchronous detection. It requires NOW WHAT exact knowledge of the subcarrier z Mechanical Analogy phase; a subcarrier sync burst is %% transmitted after each regular hori- Assume that two transparent sec- zontal sync pulse as a phase refer- (A) tions of glass are available(Fig. ence for the receiver, to provide this 3A). On one of them are printed desired phase information. the words READ THIS; on the other, NOW WHAT. Suppose we li\, get our favorite glasscutter to join III these two pieces of glass at right Til angles, as shown in Fig. 3B. If we AND WAS HIS FACE RED! look at this combination from one Technician we know was asked to

1 I angle(Fig. 3B), we can see the install an outdoor antenna on the J.1 words READ THIS. If we look at roof of a fourteen -story building in it from another angle (Fig. 3C), we New York. Job took almost all day can read the words NOW WHAT. because the superintendent insisted If we look at the unit from the an- on lead-in being fastened to outside gle shown in Fig. 3D, however, we wall at each floor. This necessitated (B) can decipher neither phrase, since going into each apartment from top / one setof words fallsover the to second floor(and finding the

-- other,obscuring both groupsof super each time another floor was words. reached.) New antenna set-up pro- NOW I/ An analogous situation is present videdamediocre picture, which HAT with respect to the use of the color owner didn't squawk about since subcarrier. The "Q" signal (similar most tenants on his particular side to READ THIS) is modulated on of the building got poor reception the color subcarrier (equivalent to also. The pay-off: A few weeks later ri one glass section); the "I" signal the owner called the TV man and 1 (C) (similar to NOW WHAT) is modu- said that an outdoor aerial which lated onto the subcarrier after the he'd purchased solved his problem, latter has been shifted in phase 90° bringing in an acceptable picture.

1 "For yearsI broadcast my morning setting up exercises-did fine-then they put me on TV"

,.. DNfliq-T14.L7

(D)

Fig.3-Mechanical analogytophase -shift- ingof color subcarrier. Two signs,painted on glassandmountedatrightangles, represent subcarrierat0 and 90 degrees. people will place the dividing lines between colors at different points. The colors in Fig. 1A are most saturated(i.e., intense) on the rim of the horse -shoe; these intensities are largely beyond the range of the present-day TV color system. The dotted -line area in the white section will be seen as white, or white with a hue of the adjacent color added,depending onthevision characteristic of the viewer.

26 TECHNICIAN February, 1954 Servicing AC -DC Radios Part 3. Odd Fading Case. Locating Intermittent Filaments Quickly

BY M. G. GOLDBERG circuit, and no fading was therefore noticeable. An intermittent in any receiver Intermittent heaters in ac -dc re- is somewhat of a headache, but a 120V ceivers are often troublesome. An AC periodicfading or cut-out in an undue amountoftime may be Sw ac -dc receiver is even worse, be- wasted in determining which tube 3525-GT 501.6-GT 12007 2567 12007 cause these receivers cost the cus- in the series string is opening up. IGI tomer comparatively little;service This applies especially to receivers 120 V charges must therefore be kept low, in which the trouble occurs only AC and any job which consumes a lot spasmodically, and then for only a SW. of bench time means money lost. few seconds at a time. Naturally, Let's consider a case in point. the technician can't spend an hour Fig. 2A-Connection of 2 ac voltmeters across The outputofthis5 -tube set or two on one of these low-priced tube filaments for first fading check. B-Volt- dropped just enough to be annoying sets, waiting around for a heater to meter connections for the second fading check. several times during a program, open. The writer has worked out a meters will reveal that one meter cutting in and out with a volume simple and speedy system for lo- is now indicating practically full line change of 15 or 20%. After trying cating the defective tube in such voltage, while the other has dropped all new tubes and making other cases, without spending more than to zero. tests, the trouble was finally nar- a few minutes of bench time on the Assume that VM-1 has gone to rowed down to the second i-f and job. zero and VM-2 to full line voltage, detector circuits illustrated in Fig. 1. Let's refer to Fig. 2A. Here we on the first fade. This means that During the fading period, the fre- have a conventional 5 -tube heater the intermittent is in one of the 12 - quency of the received station re - string in which an intermitent fila- volt heaters. Now connect the me- ment is present-one which won't ters as shown in Fig. 2B. If, on the stay open long enough for a routine next fade, both meters go to zero, check, and which cuts out perhaps it will prove that the 12SA7 is the only three or four times during an bad tube. On the other hand, if one hour's program. Note the two ac of the meters goes to zero, while the voltmeter connections. One meter other reads fullline voltage, the (VM-1) is attached across the two defective tube will be the one across higher voltage heaters; the other which full line voltage is measured. connectsacrossthethreelower This simple arrangement checks all voltage filaments. five tubes in only two fades, and Place the meters where they can almost makes child's play out of be readily seen and turn the set on, what could be a time-consuming Fig. 1-14 and second -detectorcircuitof then go to work on another bench headache. 5 -tube ac -dc receiver.Intermittentopen - circuiting of condenser "X" resulted in fading. job. As long as the continuity of the If, on the first fade, VM-1 goes to heater circuit is intact, VM-1 will full line voltage (Fig. 2A) while the mainedconstant(theoscillator read approximately 85 volts; VM-2 VM-2 reading drops to zero, con- didn't shift); the tone was not ap- will read about 35 volts. When the nect one meter across each of the preciably affected, and there was no cutout occurs, attracting the serv- two higher voltage heaters for the click when the set cut in and out. iceman's attention, a glance at the 2nd test. Connecting the scope input cable to points A, B, and C in turn showed no change in response during the fading;with the scope connected from point D tochassis ground, however, the set did not cut out. The connection just cited was made several times, with the same result. 0 The writer finally concluded that the small capacitor marked "X" in Fig. 1 (a 50 mmfd unit) was opening and closing periodically. With the scope disconnected and the capacitor open, the i-f signal was not sufficientlybypassed,causingthe audio output to drop. With the scope connected, however, the 75 mmfd capacitanceofthelatter'sinput cable was more than sufficient to substitute for capacitor "X" in the

TECHNICIAN February, 1954 27 Hi Fi GuidetoPickup

Tracking Problems, PhonoArm Location and Weight,

By HARRYMILEAF the record's grooves. Fig. 1 illus- it would produce an 8 -degree track- This article deals with the in- trates proper and improper tracking. ing error at the end of the record. To stallation, service and replacement Fig. 1A shows the needle properly prevent such a large tracking error of the arm and the pickup cartridge, tracking the groove;itisseated angle, the arm isset for perfect and also considers the part these firmly, applying equal pressure to tracking at the center of the record. units play in the overall operation both sidewalls of the groove, and fol- The error now introduced is app. -4 of a Hi Fi system. Information use- lows the lateral deviation of the degreesatthe beginningof the ful in setting up an installation, or groove with fidelity. Providing that record, and +4 degrees at its end. checking and improving an installa- the stylus itself is in good condition, tion in use, will be presented. poor tracking, as shown in B and C The pickup arm and cartridge de- of Fig.1, can be caused by poor termine,inpart,the tangency,binding,andimproper fidelityof turntable leveling. record reproduction and longevity of TTLTIS records; they should be periodically checked to insure proper operation Tangency. The needle shown in Fig. lA is properly seated only when OFFSET PIVOT POINT of the Hi Fi system. Outlined below HEAD it is in line with the tangent of the OF OW groove in which it is riding. In other words, if a line is drawn from the pivot point at the base of the tone Fig. 3-Use of an offset head (one not in line arm to the stylus tip (see Fig. 2), with the arm) and proper location of the pivot, cause the needle to finish its travel at the needle is properly seated only apoint abovethecenteroftherecord. when this imaginary line is at right This "overhang" reduces the tracking error. angles to a radius of the record. Due to design of the pivoted pick- The total tracking angle variation is Fig.1 A-Stylus properly seated in groove, pro- still viding good tracking. B, C-Improper seating up arm, the needle travels along an 8 degrees, but the maximum arc across the record; because of error is brought down to 4 degrees. are the pickup arm and cartridge this, the arm cannot maintain true Methods used to minimize this characteristics we are going to dis- tangency on all of the grooves, as in- problem include use of a longerarm, cuss in this piece. dicated in Fig. 2. The difference be- use of an offset arm, and location of PickupArm: 1. Tracking. 2. tween the needle direction and the the arm's pivot point so that tracking Weight. 3. Resonance. tangent line is called the tracking error is minimized. With a longer Pickup Cartridge:1.Weight.2. error angle. arm, the arc traveled by the pickup Frequency response and output. 3. Good tracking is provided for at isreduced;theoveralltracking Stylus (needle). the center portion of the record's angle variation is, as a result,re- grooves, to keep the overall error duced too. Reduction of the travel Pickup Arm Tracking. This isa angle at a minimum. For example: If arc, and consequently the tracking little -understood cause of distortion the pickup arm produced a total error, is also achieved by offsetting and wear in a record player. Track- tracking angle change of 8 degrees the head, and locating the pickup arm pivot in such a way as to pro- ing is the term applied to the manner across a record, and was set for per- 4 in which the pickup needle rides in fect tracking at the starting grooves, duce an "overhang" (see Fig. 3). Recordplayersnowadaysuse varied combinations of phono arm Fig. 2-Tracking angle error due to useof pivoted pickup arm. True tangencyispossible at only one point on the surface of the record, usually at the center of the groovedarea. length, overhang, and offset to improve tracking. When a phono in- LAST stallation is being made, or an arm GROOVE NEAR RECORD _CENTER HOLE CENTER OF RECORD \ GROOVE I OF RECORD is replaced, careful attention should L RADIUS OF' RECORD be given to the location of the pivot point, to prevent introduction of an incorrectoverhang.Theaverage TANGENT amount of overhang is about 3/8 inch.

ARMAT END PICK-UP When improper tangency is in- P RECORD ARM PIVOT troduced, the needle and the walls of TRACKING ANGLE GOOD TRACKING ARM AT MIDDLE OF RECORD the record's grooves will wear pre- ERROR OF RECORD maturely; excessive needle -talk and taw AT sTAR1 distortion will also be heard.

TANGENT Binding. It is very important for TANGENT COINCIDES the pickup arm to ride freely across WITH DIRECTION OF ARM the record. The pickup needle will track poorly and ride the walls of 28 TECHNICIAN February, 1954 Arms and Cartridges

Types of Pickups; Installation and Service Considerations the grooves ifit resists the lateral ing three important reasons: causes the pickup needle to rise and pressure of the grooves due to a Vertical Compliance. Proper ver- fall as it rides the record's grooves bind (see Fig. 1C). Besides intro- tical compliance requires that the (5E). If the pickup arm is too light, ducing excessiveneedle -talkand pickup needle follow thevertical it will jump and skip grooves as the distortion, this condition causes pre- modulations present in the record's pickup needle contacts the pinched mature record wear. Lubricate the grooves without reproducing any portions of the grooves. If the pick- pickup arm pivot shaft regularly so unwanted signals. The biggest ver- up arm is too heavy, the cartridge that it can ride freely, and check to tical modulation problem is the re- will tend to move excessively up and make sure that no mechanical ob- sult of "pinch effect." A considera- down when it rides in the pinched structions are preventing a free side - tion of how this effect develops will portions of a groove, causing appre- to -side movement. help to explain it. ciable second harmonic distortion. The width of a groove in the rec- Cartridge Output vs Pickup Arm Turntable Leveling. If the turn- ord depends on the width of the Weight. If the pickup arm is too light, tableis not level, the downward cutting stylus making the groove. there will not be enough lateral pres- pressure of the needle will notbe Since the cutting stylus (unlike the sure applied to the cartridge, and the applied perpendicular to the plane playback stylus) has a flat face, the outputlevelwillbe lower than of the turntable. Instead, the pres- groove it makes will be as wide as normal. If the arm is too heavy, too sure will be applied to thesidewall the stylus only when the stylus is much pressure is applied, and con- cutting in the same direction the siderable amplitude distortion will IA) 18) groove is traveling (Fig. 5A). When result (since the arm has too much CROSS-SECTION OF RECORD modulation is applied to the cutting inertia to follow lateral groove devi- stylus, it swings back and forth, and ations faithfully). Record Wear. If the pickup arm is /iii4iiaiaaiai \\.* the angle it makes to the direction of groove travel changes. The effective too heavy, the needle will apply too TURNTABLE width of the stylus thus decreases, much pressure to the grooves' walls

NEED,E and the width of the groove it makes and wear them prematurely. Con- friCSSIW is reduced (Fig. 5B). versely, if the arm is too light,it Fig. 4-The needle may ride along either side - Note in C and D of Fig. 5 that will bob up and down and also cause wall when the turntable has not been leveled. when one sine wave is cut laterally, unnecessary wear. the groove develops two cycles of As we can see, the weight of, or of the groove in the direction of the width change. This change in width thepressureadjustmenton,the turntable angle, as shown in Fig. 4. This condition will produce the poor Fig. 5A-When flat cutting stylusis moving inline with the direction of groove travel (as seating shown in B and C of Fig. 1, it does at points 2 and 4 insketch C), the grooveitcutsiswidest. B-When the flat cutting stylusis moving at an angle to the direction of groove travel (as at points 1, 3 and and cause wear and distortion. It is 5 in sketch C) Its reduced effective width causes the groove it cuts to become narrower. C- wise for this reason to check that the Magnified top view of disc surface, showing groove make by recorded sine wave. D-Sine wave turntable or its mounting board, and of (C) pulled out straight, to show width variation (pinch effect). E-Cross-section of a rec- the surface the record player will ord, showing the rise and fall of playback stylus as the width of the groove it rides in changes. sit upon, are level. It is important to note that the needle must be perpendicular to the earth's surface to seat. properly. Check the pickup arm or cartridge mountings, to make certain they maintain the needle in this position. (Such a test may often be made by placingapocketmirror,whose thickness approximates thatof a record, on the turntable, and allowing the stylus to rest on the mirror. If the needle is truly perpendicular at the point of contact, it will appear to be in line with its reflected image from any angle. Any angular deviation present will become obvious, since such a deviation appears exag- gerated when the needle's reflection is compared with the needle.-Ed.) Weight. The weight of the pickup arm is a critical factor for the follow-

29 TECHNICIAN February, 1954 pickup arm, is an important factor side the audio range, or with an arm when its replacement is necessary. that provides for damping of the The required stylus pressure de- resonant oscillations. It is important CON pends on the type of cartridge being ARROWS LABELED "Y. to note that some manufacturers use iNDICATE DIRECTION IN WHICH NEEDLE MOVES used.Informationregardingthis arm resonance to boost the bass re- LATERALLY characteristicissupplied by the sponse. manufacturer. It is advisable to check the weight Cartridge Weight. The weight of O ti-NEEDL carried by the pickup needle peri- the pickup cartridge is important be- IBI POLE PIECE Pt +-ROLE PIECE ARROWS LABELED OIRECTiON IV wNION odically, or when a replacement is NEEDLE MOVES causeofthe same considerations VERTICALLY made, to be sure that the proper presented during our discussion of 7#r pressureis being applied. Needle pickup arm weight.Itis recom- pressure gauges for this purpose can mended that the pressure of the Fig. 7-Details of magnetic pickup. Bottom be obtained for a dollar or two. If pickup arm assembly be suitably view is shown in(Al, cross sectionin(B). the pressure being applied is not in adjusted when the weight of the re- not often considered; despite their accordance with cartridge specifica- placement cartridge requires more marked advantages. tions, it should be suitably adjusted. or less pressure than the original. If the response of a crystal cart- The better grade pickup arms pro- ridgeis considered inadequate, a videcounter -balancespringsor CartridgeFrequencyResponse switch can be made to a ceramic or sliding weights that are adjustable; and Output. These are the two most magnetic -type pickup. A preampli- some provide thumbscrew or screw- important factors determining the fieris required when a magnetic driver adjustments that are easily value of a pickup cartridge. Unfor- pickup is substituted for a crystal accessible. tunately, thesecharacteristicsare type, unless the amplifier present The average amount of pressure usually inversely proportional. If we provides a low impedance input for required for the LP cartridge is 5 change a cartridge to obtain more use with a magnetic cartridge, and grams; it is between 10 and 15 grams gain, the frequency response range can deliver enough gain to com- for standard cartridges. Dual -speed narrows, and vice versa. pensate for the magnetic cartridge's arms with only one pickup needle The crystal cartridge has the high- low output. A ceramic cartridge is a should strike a happy medium. It is est level of output, but also the poor- always better to have two pickups est high -frequency response. The for this reason. average crystal cartridgedelivers about one volt, but its treble re- Pickup Arm Resonance. Since the sponse may only extend to a few pickup arm has mass, it also has, thousand cycles. unfortunately, a physical resonant Some cartridges have frequency frequency. In many of the arms on capabilities well beyond the audio the market, this resonant frequency range, but their output is measured falls within the audible range. The inmillivolts. The newer ceramic longer the arm, the lower the reso- cartridges can deliver between .1 to nant frequency. The type of material .5 v at 10 to 15 kc, which is con- Fig. 9A-A properly shaped stylus tip. B-A the arm is made of also determines siderablybetterthanahappy needle point that has been worn out of shape. its resonant frequency. medium. high -impedance device, and can be In the majority of pickup arms, Two other types of pickups some- substituted for a crystal cartridge the cartridge is securely attached to times employed are the frequency - without the necessity of adding a the arm. Thus, any motion of the modulation and strain -sensitive preamplifier. pickup needle is indirectly coupled pickups. These pickups have desir- The cheapest method of improving to the arm, and physical oscillation able characteristics, but their major the frequency response of a crystal of the arm occurs. If such arm vibra- disadvantage isthat they require cartridge is by way of frequency tion is objectionable, the arm can be auxiliary circuits for their operation. compensation.Compensationcon- replaced with one that resonates out- Where economy is a factor, they are trols and networks are sold for this purpose,andarecomparatively Fig. 6A-Compensating network for a crystal cartridge. B-Response curves for crystal cartridge before and after compensation. Note smaller amplitude variations in dotted -line response. cheap. Fig. 6 shows one compensation network that can be made up and used with a crystal cartridge to I MEG. improve performance.(The components incorporated in such a network will depend on the frequency characteristic of the uncompensated crystal. The manufacturer of the OUTPUT IN DB +5- RESPONSE OF cartridge will generally provide a re- UNCOMPENSATED XTAL sponse curve and/or recommend a 0- compensating network. It should be -5- noted that there are practical limits with respect to how much compensa- +10- tion can be provided.-Ed.) COMPENSATED OUTPUT -15 - WITH NETWORK ADDED OtherCartridgeCharacteristics. Crystal cartridges are affected by I 50 100 200 500 I KC 2 KC 5KC IOKC variations in temperature and hu- CYCLES CYCLES CYCLES II FREQUENCY midity. Magnetic and ceramic types, (Continued on page 56)

30 TECHNICIAN February, 1954 What's Wrong with Carbon Tet? An Engineer and a Chemical Consultant Present the Case Against an Old Service Standby.

This is lett as a thin film to replace BY HARRY E. SHULMAN theoriginallubricant, which has AND MURRAY JELLING, PH. D. been removed during the cleaning. Several articles have been writ- It should be noted that gradual re- ten during the past two years on the moval of lubrication and consequent useof carbon tetrachloride as a deteriorationhas been going on cleanerforcontrols andtuners. during the years the control has especially applicable in the case of Havingdevoted a considerable been in operation. some RCA tuners. amount of time to this subject, we 3. A corrosion preventativeis The proper method is to use an believe it would be enlightening to present to insure the protection of artist -type paint brush or a pipe the servicemantoexplain what the unit after the servicing. cleaner, and only apply the cleaner happens when carbon tetrachloride 4. A conductor is incorporated to to the contact areas of the wafer isused, and tolistits disadvan- counteractanyresistanceintro- switch. This procedure is effective, tages.Also, as improved cleaners duced by the lubricant. This ingre- and permits use of the unit for a have been developed, an explana- dient should not, of course, affect considerable length of time before tion of their action and the methods the characteristics of the component servicing is again required. Appli- by which they should be applied part. One manufacturer uses a ma- cation of the cleaner by spraying should be valuable to the service- terial known as "Metacote" to im- should be avoided, as this method man. part this property to his product cannot be restricted to the contact Under no circumstances should (Mute -Tone). areas alone, and a definite drift is carbon tetrachloride be used on An efficient product should con- apt to follow suchimproper electronic parts. Controls are usu- tain ingredients to perform all of cleaning. allylubricated, and carbon tetra- the above functions in an expedient On the Standard Coil type tuner, chloride is such an excellent solvent manner for the serviceman. The the use of a cloth was found effec- that the lubricant is completely re- product should be supplied with a tive. A small quantity of the cleaner moved. The part may be in working dropper attachment, and the serv- was placed on the cloth, and the order for a day or two, but the re- iceman should be equipped with a contact. areas were rubbed. After a moval of the lubricant leads to fric- small brush, a cloth, a pipe cleaner, few complete revolutionsofthe tional wear, and the trouble will ap- and a toothbrush, so that all types of tuner,the contacts were cleaned pear and remain thereafter. controls may be cleaned easily and and lubricated. In addition, carbon tetrachloride properly. On the Zenith type tuner it was causes corrosion. Even traces of this found that the use of a toothbrush solvent will react with moisture and Cleaning Controls was the most efficient method of produce hydrochloric acid. Moisture In applying the cleaner to con- servicing the contact areas. is present in the air, and the cooling trols,such as volume, horizontal Regardless of the method of ap- effect of the carbon tetrachloride as hold and contrast potentiometers, a plication, carbon tetrachloride was it evaporates will cause condensa- few drops from a dropper are per- found to be a detriment to servicing tion on the metal surface. The ab- mitted to fall on the spaces around controls and tuners. This cleaner sence of the lubricant, and the pres- the pot terminals; the knob is then may eliminatethe trouble fora ence of the moisture and the acid, turnedbackandforthseveral short time, usually a day or two, will cause corrosion of the metal, times. This procedure will usually but the trouble returns and servic- leaving a white film. 'This is prob- clean the dirty control effectively. ing is required again. This type of ably zinc oxychloride, as the metals In most cases the control may be servicing is of course unsatisfactory, present are generally zinc alloys. cleaned without removing the chas- as it is time-consuming and causes This film and the corrosion will ef- sis from the cabinet. This is done a loss of confidence in the service- fect the characteristics of the con- by tilting the cabinet, and allowing man. Since improved cleaners are trol, and lead to more trouble than a few drops to run down the con- now readilyavailable, servicemen existed before the part was cleaned. trol shaft into the control. After a should make use of them. Cleaners have recently been de- few turns of the knob, the control Drum of Zenith turret tuner. Stationary contact veloped which eliminate these diffi- is cleaned. surfaces may becleanedwithtoothbrush. culties. Essentially these are based on several ingredients. Cautions on Cleaning Tuners ..44.1.14.4.1 44.11._4.1.°b. 1. A solvent is used which is an .' -... excellent cleaner, but is non -corro- Greater care must be exercised in 4-4 4 4.4' .t 1.1. I,I , I. 0...1 1R cleaningtuners.Whencleaning ,.., ..... sive in contrast to carbon tetrachlo- a:4 4'4 1, rr0 P 0.r r, s. ride. The evaporation rate is slower, wafer -typetuners,anexcessive .- r... ov , I. 6 which reduces thetendencyfor amount of the cleaner must not be l'A.1)4.4, ti I,01, 1--1,- cooling and condensation of mois- permitted to be absorbed by the rr4=1-FIL-71171:r ;# ture on the metal surface. wafer material, as this may cause 2. A lubricantisincorporated. the tuner to drift. This caution is

31 TECHNICIAN February, 1954 Troubleshooting Drift

Tests and Remedies for a Tough

BY PHILIP THIER shop. The set, it was found, used a position with respect to the center One of the most difficult TV serv- turret tuner with structural fea- body of all the trimmer capacitors ice jobs, perhaps, is the correction turespeculiartothisparticular was marked; the chassis was then of frequency drift in tuners. The make of receiver. In electrical de- operated inside the cardboard box. simplest cases of drift are caused by sign, however, it was similar to the After the drift had occurred, a defi- faulty oscillator tubes. These may general run of commercial turret nite change of position of the "top - have loose elements, causing the in- tuners. hat" was observed on the two trim- ter -electrode capacitance to change Bench tests on the receiver re- mers previously referred to. periodically just enough to shift the vealedonlyfront-endmisalign- It now became apparent that the tuner all over the selected channel. ment. After realigning the set,it was kept in operation for a few GLUE IS PLACED A quick tube replacement, followed, OVER SCREW AND ifnecessary, by a slight realign- hours to see if the drift recurred. It SPRING CLIP ment, will clear up the problem in did not, so the set was returned to such a case. The more difficult cases, the customer. those which drive the serviceman to The following day,the set was distraction or into a defense job, back in the shop with the original will be considered in this article. complaint. This time the tuner was Let's consider first the complaint cleaned thoroughly before being re- which was made to the serviceman aligned. The set was operated on as follows: the bench for three hours, but no drifting occurred. A cardboard box was then placed around the chassis, HERE GLUE IS APPLIED INSULATED SCREW to TO FASTEN'TOP ON WHICH OUTER simulatethepoorventilation PRE-SET POSITION ON CYLINDER RIDES Fig. 2-Tubular trimmer capacitor. SCREW SHAFT present when theset was inits HEX HEAD PERMITS L cabinet. In a few minutes, the tuner ADJUSTMENT glue holding these two "top -hats" in began to drift all over the band. position was at fault. Most likely the trimmers had been adjusted in VFIT'ETOP CYLINDER O Following Up Clue some previous repair, and the serviceman had been carelessin his INNER CYLINDER choice of a proper bonding agent. REMAINS STATIONARY An important clue had been dis- covered. What particular compo- (It is very important that the bond- nent, however, was at fault? One ing agent used in tuners be of such Fig. 1-"Top-hat" type of tubular trimmer lead that seemed worthy of follow- composition that it will not expand up was the fact that in each align- or contract to any considerable de- "Iwaspeacefullysippingan ment, the same two trimmer con- gree with temperature changes. The after -dinner highball and watching densers required the major adjust- compound must also be an excellent the news on Channel 4. Suddenly ment. These were in the oscillator insulatorat highfrequencies,as both picture and sound faded out. and mixer circuits. A detailed test well as for fairly high de potentials.) By the time I got to the set to see and inspection of the trimmers and The old glue on the tuner was re- what was wrong, the picture and all other components in the two cir- moved;afteralignment,agood sound began to come back on. But cuits resulted in the conclusion that quality polystyrene -base coil dope you better come on over quick. It there must be an easier way to was used to lock the trimmers in wasn't 4 that came up-it was 5. make a living. All parts tested good. place. The trouble was now cured Either that set is changing channels The mechanical assemblyofthe to the satisfaction of all concerned. by itself or else I'll have to change tuner next received careful inspec- This case history has been pre- my brand of liquor." tion. The close,detailed scrutiny sented in detail toillustrate just Well, he didn't have to change his paid off by revealing the trouble. how obscure tuner troubles can be. brand. There was enough drift in All trimmers used in the tuner It also was intended to demonstrate the tuner to shift the reception clear were of the "top -hat" or tubular a useful method for locating the over to another channel. When he type (see Fig. 1); after adjustment, trouble. made the home call, the serviceman such units are covered with glue to found the tuner set on Channel 4; hold them in place. It was previously Tubular Capacitors Channel 5 soundwascoming indicated that a rise in temperature through strong, but the (Channel 5) was linked with the oscillator drift. The "top -hat" trimmer used in picture was weak and snowy. Normal expansion of the condenser the tuner we have been discussing At first inspection, the technician material (due to heat) could not is just a special form of tubular ca- reasoned that theoscillator tube cause so drastic a change of fre- pacitor. Another kind of tubular ca- was at fault. Its replacement, how- quency. What about abnormal ex- pacitor is illustrated in Fig. 2. Be- ever, brought no improvement. The pansion, however? To check on this cause they can be made to cover a chassis was then taken intothe phase of the matter, the "top -hat" wide capacitance range from a frac-

3 2 TECHNICIAN February, 1954 in Television Tuners

Service Problem. Case Histories tion of a micro-microfarad on up, material employed is a ceramic which lation with carbon tetrachloride. If tubular trimmers are being incor- also serves as the dielectric material any cracks exist, they will show up porated in TV tuner design more of the capacitor. as dark streaks, while the rest of frequently, now that UHF is here. As in the case of the feed -through the insulation will remain clear. In the "top -hat," the outside case terminals, the ceramic can be dam- It is extremely important to re- is movable and the center is used aged by excessive heat or mistreat- place any resistor in the front end for mounting. The other type of tu- ment. Breaking the ceramic will re- whichmayhavebecomeeven bular trimmer is supported by the sult in a short; the defect is readily slightly overheated due to a short spring clip at the top; the center apparent to the eye. In both the ter- circuit. Any excess heat will cause slug is movable. The usual practice minal and the capacitor, the main the insulating material around the with both types is to cement the source of trouble lies in cracked in- resistive element to crack. This, in movable partattheadjusting sulation. effect,placesanotherresistorin screw,afterappropriatelysetting parallel with the overheated one. the screw. Hence, many tuners be- Dust and Dirt Troubles Since this "effective resistance" is sides the one previously described usually of a varying nature, tuner may be caused to drift by tubular stability will be seriously affected. trimmers that have been "gummed These cracks, which usually ex- A cracked resistor will also ex- up" with a poor grade of glue. tend from center post to the mount- hibit varying capacitance character- Widespreaduseisnow being ing ring or screw, as the case may istics. (Carbon and composition re- made of insulated terminals as tie - be, become filled with dust and dirt sistors have an appreciable distrib- points or feed-throughs to facilitate in a very short time. Now, dust in a utedcapacitance whose shunting wiring. In tuners, the feed-throughs TV receiver is composed largely of effect varies with frequency-Ed.) (see Fig. 3) are used to bring con- metallicparticles.Although these The instability thus caused becomes nections through shield plates and particlesarebunchedtogether more pronounced as the frequency cans. A one-sided terminal be loosely and provide a poor or, at best increases. A defective resistor used when a tie -point is needed and a varying resistance path for dc, kind just described is one of the it is inconvenient to use a spare lug they will act as a series -connected things to look for when a set drifts string of capacitors to ground, caus- on the higher channels (7 to 13) but ing loss of r -f, oscillator or i-f sig- not on the lower ones. nal voltage. Some servicemen may replace a If the terminal is carrying i-f sig- shortedcondenser and make no t..---- GLASS INSULATOR nal, the capacitance introduced by tests for further damage, to get the the metallic particles may affect the set out of the shop quickly. Such plate circuit of the mixer stage or haste is not good business practice. the grid circuit of the first stage A little extra care and time spent (see Figs. 4, 5). Since this stray ca- on the repair will prevent a costly pacitance does not remain constant, call-back later on. its detuning effects on the mixer and i-f stages will not be constant ReplacementCautions Fig. 3-A feed -through terminal. either, and fading or drift will become evident. A loss of synchroni- Whenever any part replacement is on a tube socket, or when no such zation may be present as well. In- made inatuner,the new part spare lug is available. cidentally, a cracked tube socket in should be placed electrically and The glass insulator on such ter- the tuner can produce the same ad- mechanicallyexactlyastheset minals may break, with the termi- verse affects on reception. designerintended.Aneffective nal shorting to chassis, but this is A varying resistance path instead rare(as well as obvious). More of a varying capacitance to ground Fig. 4-Feed-through capacitor. The ceramic often, the glass will crack, due to may be the problem encountered insulator, when cracked, creates a low -resis- the application of excessive heat in when a feed -through capacitoris tance shunt path (indicated by dotted lines). soldering, or because of over -ener- crackedandthecrack becomes getic tapping during a search for filledwithdirt.Sincethefeed - loose connections. through capacitor is used to bring Similar in appearance to the feed - B+ voltage through the shield, the throughterminalisthefeed - varying leakage path introduced in through capacitor (see Fig. 4). This the case just cited will tend to cause MOUNTING SLEEVE

unit is used in TV tuners to bring the plate voltage of the oscillator CERAMIC INSULATOR the B+ lead through the tuner tube to vary. This may cause unde- shield, or through shield plates be- siredchangesinoscillatorfre- tween stages.Itserves the dual quency, and the receiver will,in purpose of feed -through terminal consequence, exhibit drift. and bypass capacitor. The insulating To locate cracks, brush the insu-

TECHNICIAN February, 1954 33 4. Careful and precise electrical TUNER SHIELD r FEED THROUGH tests of all circuits in tuner are also r TERMINAL recommended. 5. Replace defective parts with exactduplicates,maintaining the original physical placement and lead dress. 6.Precision alignment is advis- TO RFI able. Obtain the set manufacturer's AMP recommended alignment procedure, if possible. FEEDTHROUGH CAPACITOR 7. Before returning set to customer, keep it in operation on the bench for a few hours. This will help prevent costly callbacks.

"Conditions of Repair" Card One of the novel ideas of Bonded TV Service, Inc., of Belmont, Mass., is a printed "conditions of repair - Fig.5-Typical mixer -oscillator front-endcircuit.The condenserindottedlinesillustrates service" card which has been widely theeffectiveshuntcapacitanceintroduced by acrackedfeed -throughterminal;the dotted -line copied throughout the Massachusetts resistorillustrates the possibleeffectof a crackedfeed -throughcapacitor. area. The card is printed on both sides. It reads: method of doing this is to sketch afterward. This source of drift, in- "Conditions of this repair service. the exact placement of the defective cidentally,is an often overlooked Be certain that your set has been part before removal. Lead length one. Monitoring the B+ line with a adjusted to your satisfaction before and dress must be kept the same. A voltmeter, as in the preceding case, our serviceman leaves. Recalls will straight wire 0.04 inch in diameter will help localize the trouble. Re- not be allowed for adjustments. and four inches long has an induct- placing the rectifier or filter con- "Since many circuits and tubes ance of 0.1 microhenry. At standard densers (when tests confirm that combine to make up the picture and broadcast frequencies, this induc- they are defective)will eliminate sound, we cannot assume respon- tanceisnegligible;at100 mc, driftcaused by such component sibility for future breakdowns, even however, itrepresents an imped- defects. immediately after repair is made. ance of about 65 ohms. The choking To avoid introducing drift into a "Partsand tubesusedinthe effectofsuch an impedanceis tuner when it is being serviced, ob- repair are guaranteed for one year obvious. serve the following precautions (in and will be replaced without charge, Under certaincircumstances,a addition to others previously cited): except for service, provided Bonded TV receiver will exhibit symptoms When making soldered connec- TV Service Co.iscalled tore - of tuner drift, yet no defect can be tions, use as little solder as possible. service set at regular charges. found in the tuner. This is espe- At high frequencies, a glob of solder "Itwillbe assumedthatthe cially common in receivers using may act as a capacitor. A cold -sol- repair has been properly made, selenium rectifier power supplies. dered joint may become intermittent, unless our main office is notified to These rectifiers are often sectioned, and will always add resistance to the contrary within two days." to supply different voltages to vari- the circuit. Keep the soldering iron Another "first" by Bonded was ous parts of the set. A common hot and use a high silver content the origination of service advertis- fault in selenium rectifiers is that solder(ifobtainable). Any rosin ing on the TV page of Boston news- the output voltage will vary if the flux present must always be re- papers, and visual advertising over oxide element is slightly defective. moved from the connection, as it in- TV Station WBZ-TV once a week. troduces averylowresistance Bonded operates on a strictly cash Plate Voltage Changes shunt path at very -high and ultra- high frequencies. basis. "Credit does not work in this Should this occur in the rectifier The most valuable commodities business," manager Widisky said. section supplyingthetuner,the the service technician has to sell are MyCompetitor varying oscillator plate voltage that his time and knowledge. To make My competitor does more for me results will tend to produce corres- better use of both when trouble- than my friends will do. ponding variations of local oscillator shooting drift, the following pointers My friends are too polite to tell me frequency. Other stages, of course, should be kept in mind: what I ought to know. will also be affected, but the oscil- 1. In searching for the cause of My competitor makes me efficient, lator -caused symptoms will gener- trouble, remember that defects in diligent and attentive. allybethemost noticeable. A receiversectionsother than the He makes me work and search for vacuum -tube voltmeter connected tuner can cause drift. new ways to improve my service. to the tuner B+ supply line will in- 2. Since even a tube replacement My competitor would take my busi- dicateanyvoltagefluctuations, in the tuner may necessitatere- ness away from me, if he could. helping identify this kind of trouble alignment, it is recommended that This keeps me constantly alert to when present. all tuner repairs be done in the protect what I have. Poorpowersupplyregulation shop. If I had no competitor, I would be may cause the set to be unstable or 3. A very thorough mechanical in- lazy, incompetent and independent. drift during the first fifteen minutes spection of the entire tuner assem- I need discipline. I like my competi- or half-hour after it is turned on, bly should be made when trouble- tors. They have been so good to me. with receiver stabilization occurring shooting drift. -Sales Story 34 TECHNICIAN February, 1954 Eliminating Tweet Interference

Part 2 of a Series on Lead Dress Troubles

BY CYRUS GLICRSTEIN stages, particularly the video detector. If moving the lead-in reduces The most important video defect the tweet_ symptoms seen on the which can be caused by lead dress screen, it is advisable to staple the is tweet-an r -f interference pat- lead-in along the top of the cabinet, tern generated internally in the reas far from the video i-f section as ceiver. The tweet frequencyis a possible.It may be necessaryto harmonic of the video or sound i-f lengthen the lead-in, to obtain the carrier. This harmonic is fed from maximum reduction in interference. the video detector back to the tuner, Ifthe tweet isnot caused by beats with the incoming picture or pickup in the antenna lead-in, it is sound r -fcarrier, and causes an advisable to determine whether it interference pattern to be visible on is originating in the sound or video For clearing tweet interference the screen. i-f section. This can be done, as de- originating in the video i-f section, The tweet patternisusually a scribed previously, by simply check- the following is recommended: continuously changing one. It can ingmathematically - determining a) Try shielding the 4th video generally be distinguished from ex- whether the sound or video i-f har- i-f, video detector, and video ampli- ternalinterferencebyasimple monic falls in the channel tuned in. fier stages, when such shielding is test. Vary the fine tuning control. Another check consists of removing absent. Ifthe TVI pattern seen changes the first sound i-f tube and noting b) Wires from the video detector from thin diagonal or vertical lines, if the tweet effect disappears. If it circuitshouldbeshort,dressed to broad horizontal lines, and back does, it is originating in the sound close to the chassis, and away from to diagonal lines, as the fine tuning i-f section. other wiring. is slowly varied (see photos), the Possible procedures for clearing c) Determine, bybridging and interference pattern is probably due up tweet interference originating in resistancetests,whetherbypass -generated tweet. the sound i-f section include the condensersinthe 4th picturei-f To verify this, figure out whether following: platecircuit, the r -f bias circuit, any harmonic of either the sound a) Check sound i-f and discrim- and the video i-f plate and screen or picture i-f is close in frequency inator transformer shield cans and circuits are in good condition. to either the sound or videor -f wiring. The cans should be tight in d) An outdoor antenna should be carrier, on the channel (s)where place and well grounded tothe tried on receiversusingbuilt-in the interference is present. If itis, chassis. antennas,sincethe outdoor unit a tweet is probably the cause of the b) Lead dress in the discrimina- provides a better signal, less sus- TVI. tor stage, especially that of discrim- ceptible to interference. A built-in In most cases, the tweet is caused inator transformer wiring, should be antenna is apt to pick up more tweet by pickup of the i-f harmonic in the short and direct. interference than an outdoor one. section of transmission line between c) All bypass capacitors in the In the case of particular receiver the antenna terminals and the tuner. sound i-f section should have leads models, where the tweet problem is The trouble may be due to the in- as short as possible; the capacitors present in aggravated form, service sufficient spacingofthisantenna themselves should be dressed close bulletins of the set manufacturer lead-in from audioor videoi-f to the chassis. should be consulted.

TVI caused by twee varies from narrow diagonal lines (left) to broad horizontal lines (right), asfine tuning control is rotated slowly.

35 TECHNICIAN February, 1954 Modern RussianTV Receiver

Diagram and chassis photos provided byU. S. Air Force offer American techniciansopportunity tocompare Soviet and American designs.

The late -model Russian TV set whose schematic isshown on this page is known as the "Leningrad" T-2. Itis a single -channel job using 32 tubes. Set would sell for about $400in the United States. Picture tube hasan 8 -in. screen which emits a green light. A. C. Omberg,Engineering Director of Bendix Radio Division, Balti- more, Md., recently demonstrated this set during thecourse of an interview with T. White of WBAL-TV.

Separate power supply and AM tuner chassis are used in the 1-2. Soundsystem present is a split -carrier; sound take -off point is at the plate of the converter. Circuitry seems very similar to that present in Americanbourgeois receivers. (Note Equivalent Tubes chart, bottom of this page.)

.6.1.111.111. 020.2100 Goolle/01 V1100IP /110.114

1.11 11001

.7C144 110*

021

1.0111104 012:0111102100 203 00 00.iF12 100

101110.1TE I

1-C44 los

C42 *FL

411 WM( 1011424 01:20014sang. LAI 021121ME2 AftIf. 21124.1200 2.14 0111C10111

.,a

f u41.00121

Traue "llama

EQUIVALENT TUBES r 1.31 L32 1.22 121 OS' RUSSIAN SAC? SAC7,6114 U=1 646 606 RR OSC 05C %NE 6J5 61115,6C2C 'I:4.n °Tamara PUSH -1<500 65N7 61184 BUTTONS l04070.3 0.3 0//POI acrarcacwodas CB 25 31 00049 TO JIB 6F6 606 121 141 PICTORIAL VIEW- TUNING ON 524 544C MIDICATIS 04(4040 CB ANOXL8 BANDS 23LKIB 23.116111 GAG? SAG7,6119 6547 6541,51113 6V6 6V6,61T6C 6567 6547,647 JP -50,L550 11T-50,rY-50

36 TECHNICIAN February, 1954 (Above) Rear view of Russian receiver's interior8. 15KV clear plastic cap. 1. & 2. Manufacturingmark 9. Sleevedresistor,R121 3. AM tuner SerialNo. 10-12. Manufacturing mark 4.Hi -V Diode Access Door 13.Vert. Lin.(upper) control 5. 900 Antenna Connector 6.Manufacturer's mark 7. TV chassis serial No. (Right) Exploded view of CRT assembly 8.Interlock,Female Conn. 1.RetainingRing 9. Power supply serialNo. 2. ManufacturingMark 10. Sourcevoltageselections 3.High Voltage Contact 4. Tube Type (Above Right) Front quarter view of the te.e-5. Manufacturing Mark 6.Retaining Spring vision chassis 7. HairFeltPad 1.to 4. Manufacturing mark 8. Safety Glass 5. Focus coil 9.Molded End Plate 6.Deflectioncoils 7.Manufacturing mark

0.01100100..0C115100.1. 110 0050 M.,. 511C YAP, CAM.

00111 479 soma it

LIR

11.39.14 13'40111

L13 -1,Vse :77 111, 1004 arwerwas 19.11/191 aea

9110 0.101Lon. I11- 005r32011. WOO -Ffir5p1 , 09 owns WIN

0 Mt Bak 059

RUM

3021_11 5 W. 121 TR 01 =Mir 9[=/1111 041.-01. aC1--ra el= 9_ 413

1 4,C1r-r. R0190.1 SWITCN.ICTION IC ZOLL.1 .11=Au re

VIOLli R 0914914

C00.

511:4 ROM 0111.01110 340 PULP.

ta1010. 10111/1 LtilThel SELECTOR 1 iNN 40. S0000

TECHNICIAN February, 1954 37 for Ailing CRTs rent flow to the heater. One jobber five leads coming out of the crt here has run out of sockets lately, arefairlytender copper -oxide pointing up the prevalence of this coated leads. To feed these through trouble.-M. G. Goldberg, St. Paul, the pins of the base, the average Minnesota. technician first heats the prongs of the base and shakes off the solder. Rebasing Technique Then he tries to thread the five leads Ever have a picture tube base thru the five prongs. In many cases came off in your hand when remov- these wires are so short that one ing the socket? There is a solution can't be quite sure that they are ac- to this problem that will probably tually through the base pins. In such result in a better connection than a case, file these base pins down a the original bond between the glass little,as indicated in the sketch. bulb and the tube base. Carefully When thecrtleadsarefinally remove any remaining leads from threaded through the proper base Soldering Cure for CRT the socket and clean them as close pins they will now be actually seen When apicturetube filament to the bulb as is possible, then solder protruding. You can believe me that seems open, many servicemen will three-inch tinned no. 18 wire leads thisisquitereassuring.Ihave replace the crt with a new one. A to the original ones. Clean all resid- shown several of my friends just wiser procedure is to first use a very ual glue from the base, and remove how I do it and the invariable com- hot soldering iron on the prongs of solder from the pins. Drill a %-in. ment is: "Boy, this sure is a swell the picture tube itself. A high re- way of doing it. It takes me twice as sistance joint, or oxidation on these HOLE DRILLED IN KEYWAV long the other way and I am never filament prongs, may be the cause 3-IN.LEADS EXTENDING sure that all the leads are actually in of the crt filament not lighting. Heat- THROUGH PINS BASE IS FITTED the proper base pins and firmly ing up the prongs will return the TIGHT ON BULB BEFORE soldered. This way you can see what tube and set back to normal in such WAX IS POURED IN. you are doing." a case.-Gelman's TV, Philadelphia, Here are details on the proce- Penna. dure:File down the base prongs ----EXHAUST STEM about %2 of an inch. That will ef- Socket Replacement fectively remove all of the solder Here is a hint which may be of from the hollow prongs. Carefully value in servicing early 1951 RCA clean the leads with fine sandpaper. Technique for rebasing picture tubes by adding Removeallexcess dried cement models, such as 6T53 through 6T87 lead lengths and cementing with sealing wax. sets. Customer's complaint:sound from the inside of the base. Now but no raster. I find no glow at the hole in the flat portion of the key- carefully thread the leads through crt filament. After a slight movement way of the base, and thread the the prongs of the base. They will not of the crt socket, the tube lights and tinned leads through the proper pins, only show but will actually come out the set works ok for a day, a week, pulling the base down tight on the of the prongs about of an inch. or sometimes a month. Then an- bulb. Then bend wires over the pins, other call. The rear of the socket is as shown in the figure, to hold the removed, the leads are resoldered, base in that position. Place tube on and the pin contacts are tightened. floor, face down, and pour hot seal- A few days later the same trouble ing wax in the hole drilled in the occurs. I repeat the same procedure. keyway, until it completely fills the BASE OF Then I run a little Lubriplate or interior of the base. Then solder PICTURE TUBE Walscolube in the socket contacts, pins, and clip off excess wire. When hold a hot iron against the tube pins the sealing wax is hard, the tube ___FILE PRONGS to make sure contact here is ok base should be able to support the DOWN ABOUT I/32 and reassemble the socket. A month entire weight of the picture tube, the goes by and the same thing hap- strain now being on the exhaust pens. In disgust, I replace the socket. tube in the center of the base.- Rebasing may befacilitated by filingcrt I tell the customer if the same thing Walter C. Souders, Ambler, Penna. prongs down to make them 1/32 in. shorter. happens itis undoubtedly the pix tube and leave. No more calls. This, Moreon Rebasing Pull the base back just a trifle. Ap- of course, happened only on the first Many technicians of my acquaint- ply service cement both to the base job of this type. Since then I have ance go about rebasing a picture and the glass sparingly. Allow it to replaced almost a dozen sockets on tube with trepidation and lack of stay for about two or three minutes. the firstvisit, with no callbacks. proper technique. The tube usually Then pushthebase up snugly Seems that, regardless of how tight belongs to a customer. When the against the glass. Allow about half the contacts are around the heater base inadvertently comes off during an hour todry. Solder leadsto socket contacts, a microscopic layer handling, the shop owner is respon- prongs. With a fine file, remove ex- of corrosion develops, and a slight sible for an expensive component. cesssolder.-B.0.Riis,Miami, rise in resistance prevents full cur - It must be remembered that the Florida.

38 TECHNICIAN February, 1954 Prescriptions for C -R Tube Service Problems. Removing Faults, Replacement, Reactivation Arcing Remedy correct placement of the ion trap.- Wallace Cantoni, Landisville, N.J. If corona or arcing is experienced at the anode button, it is probably due to an accumulation of dirt, or Removing Internal Shorts the effect of a corroded rubber suc- A cathode-ray tube occasionally tion cover. The following procedure developsagrid -to -cathodeshort; is recommended toeliminate the such a short may be intermittent. trouble. This trouble may be hard to locate, 1. Disconnect the anode lead from and it is often solved by replacing a the tube. 2. Clean the area around costly picture tube. I have found that the anode button with carbon tetrachloride or a scouring compound. 3. Add a protective coating. It has been found that the use of Crosley Appli- ance Polish(part number 81527) of all low -emission picture tubes can after the surface has been cleaned be restored. I can't confirm or deny will give this protection. this statement but, with my method As an added precaution:If the (no special equipment required), we original anode connector is without can settle for a 30% figure. a suction cover, thus permitting free GRID *I, PIN 2 Only two items are required: An accumulation of dirt,or ifit has A ordinary tube checker, to supply a a rubber cover, which could be the CATHODE, PIN II variable source of heater voltages; source of present or future trouble, and a TV chassis, to supply a de ALLIGATOR a new anode connector and lead as- ALLIGATOR CLIP TO source of from 25 to 60 volts. (Some CLIP TO CHASSIS sembly should be used to replace the H V OUTPUT receivers provide a variable dc volt- original assembly. This new assem- age on their brightnesscontrols, bly should have a neoprene suction ranging from zero to 120 v or more. cover which will resist corrosion and On Philco 50T1401 and similar sets, prevent accumulation of dirt around Set-up for removing grid -cathode short in crt. for instance, 0 to 155 volts is avail- the anode button. If this procedure is able at the brightness control.) followed, re -occurrence of problems many tubes can be saved by flash- Consider the grid -cathode assem- of this kind will be held to a mini- ing, which separates the shorted ele- bly of the electron gun to be a mum.- (courtesyCrosleyService ments.Simply removethetube diode. Tie one heater leg to the Dep't.) socket and the hv connector; then, cathode; then tiethis junction to using two clip leads having good Rapid CRT Replacement quality insulation, ground pin no. 2, the grid. Now connect pin no. 11, the BARIUM -CESIUM This technique, which I have used cathode, to the high -voltage lead. DEPOSIT ON CATHODE often, may be of help to other tech- Turn on the set and lightly tap the nicians who service RCA 21 -in. re- neck of the tube. (We would recom- HEATER ceivers. We have had many 21AP4 CONTROL GRID mend leaving the set on for no more CATHODE picture tubes go negative or lose than a second or two at a time, to emission, thus making replacement prevent damage to hv components. TO CENTER TAP necessary within the first few months The high -voltage arc between grid 1-8.PIN OF 2 BRIGHTNESS after the set was sold. Ordinarily CONTROL (25-60 V) and cathode will often force these PIN I the chassis has to be pulled to re- elements apart, clearing up the short 6. TO HEATER CONNECTIONS place the tube, but the method I use OF TUBE CHECKER and saving a costly picture tube.- 1 PINS II AND 12 is faster and easier. After discon- Walter C. Souders, Ambler, Penna. ON PIK TUBE necting the high voltage cable, crt BASE GROUNDED socket and ion trap, remove the two 3i -in. screws holding the supporting Pix Tube Reactivation bracket for the deflection yoke to Normally, if the pix tube is weak Set-up for reactivating crt's with low emission. the top of the cabinet. You can then itisbest tosell the customer a remove the supporting bracket by new one. However, it is sometimes ground. Impress 25 to 60 volts on the tilting it to the left just enough to possible to restore satisfactory emis- grid. Keep this voltage as close to 25 clear the top of the cabinet; then sion in the old one. In the manu- volts as possible, because ion bom- you slipitoff over the neck of facture of the crt's electron gun, the bardment of the cathode may oc- the tube. After this is done, you can cathode is coated with a cesium - cur at higher voltages, if the vacuum remove the picture tube by turning barium powder. This coating (.003 is not tight. Connect the heater leads its face or front to the left (away to .005 in. thick) is rarely activated to any convenient pair of heater pins from the high voltage cage). The to full depth. It is possible for the in the tube checker, but make sure new tube can then be installed in a serviceman to take advantage of this the ungrounded heater lead is not matter of minutes, without removing fact by reactivating the remaining groundedinternallyinthetube the chassis. Usually the only adjust- powder on the cathode. Some manu- checker. Then use following proce- ment that need be made after re- facturers of equipment built espe- dure: installing the yoke assembly is the cially for this purpose claim that 90% (Continued on page 64)

TECHNICIAN February, 1954 39 in January. Field clinics to train Sylvania dealer -servicemen are now in the works. The first RCA color Co LO R clinics, each consisting of four days of intensive instruction and demonstration, were held for the benefit SHORTS of receiving set licensees. New York and Chicago were the sites for the INSTALLATION procedurefor other, the set owner may have to first two such clinics in January. The color -TV receiver was demonstrated readjust fine tuningregularly. Los Angeles clinic begins on Feb- by RCA personnelat conference Chroma and phasing controls may ruary 8. Similar clinics for service called shortly after FCC announce- also haveto be readjusted with groups will be held in 65 key cities ment on NTSC standards. Color pix every switch -over to another chan- throughoutthecountry,starting tube was not mounted on chassis, as nel, to compensate for minor differ- early this month. is usual with B & W sets. The tube, encesintransmission.Improper packed in a separate carton, had to phasing may result in wrong -color RETMAis now working on a be mounted in the cabinet. Unlike reproduction (red for blue, blue for color -TV lecture program for tech- conventional crt, the color tube must green, etc.). nicians. The program, as now probe oriented for a single correct posi- posed, will be offered to sponsoring tion;the built-in mask must be SERVICE CONTRACTS, in- organizations as a package deal. The aligned with the cabinet opening and formed sources say, are expected to package will include: a lecture text; the blue gun in the neck of the tube cost about three or four times more an illustrated booklet, on which the must be uppermost with respect to for color sets than for B & W re- lecture is based, to be distributed to red and green guns. ceivers. First -year contracts should audiences at the time of the lecture fall between $170 and $300,app. asastudyguide and reference THE HI -VOLTAGEregulation These figures, of course, represent text; a series of 35 mm strip films to adjustment will have to be made an early condition. Contract charges supplement and illustrate the lec- (screw -driver control) with a meter should fall in a year or two, as was tures; and a lecturer's guide pamph- when the receiver isinstalled, as the case with initially high B & W let recommending procedures and correct hv value isimportant to contract costs. techniques for most effective use of proper beam convergence and color the lecture material. registry. A good B & W pix is the THE LAWRENCE COLOR TUBE, next thing the receiver is set up for. employing a single electron gun, may DR ALLEN B. DU MONT fore- Carried out with a linearity or dot get a bigger play in '54. A step-up sees 21 -in. color sets at $500 each, generator,orspecial convergence in output of this crt was foreshad- but does not believe this point will checker,thisprocedureprevents owed with the addition of new grid- be reached three years. B & W pix from being marred by producing facilities by the Chromatic He anticipates limited -quantity pro- color ghosts. Television Laboratories of Califor- duction of color -TV in general until nia. Grids have been a principal bot- 1956. He believes cost factors will COLOR PURITY ADJUST- tleneck in the production of Law- block an immediate swing to color. MENTS are then separately made rence tubes. An annual total output Full integration may take 10 to 20 for the individual primary colors, to of more than 25,000 grids was fore- years. insure uniform saturation for each cast for the new facilities, with pro- across the entire crt screen. Then duction starting by the end of March. HOME STUDY COURSE IN the balancing controls for each pri- The grids will be used in the manu- COLOR TV for technicians already mary are manipulated, so that all facture of 21- and 24 -in. color pix versed in B & W circuitry and three together give a uniformly grey tubes. The Lawrence design is said service will be offered by RCA In- raster. Saturation adjustments, made to pave the way for these large - stitutes of New York City. Consist- next, may depend onindividual screen tubes. Thomas Electronics of ing of nine lessons, the course will judgment. If they are set too high, Passaic, New Jersey, manufacturer of cover the following subjects: Intro- however, the excessive signal pres- conventional B & W crts, will handle duction to Color TV; Principles of ent may overdrive the crt, causing the fabrication of the color tubes Light and Color; The Color TV Sys- color distortion as well as possible themselves, under a recent licensing tem; Receiver Principles; Color Pic- tube damage. agreement. ture Tubes; Receiver Circuitry; Set- COLOR SERVICE SCHOOLS and upandAdjustmentProcedures; RECEIVERS may be hinged on Alignment and Servicing; and Spe- top to facilitate picture tube instal- clinics have already been started by cial Test Equipment. For a bulletin lation and access to controls. The at least three manufacturers. West- inghouseclaimsthefirstservice describing the course, write to Home front panel of one proposed com- school (December) at its plant in Study Department, RCA Institutes, mercial model features more than Metuchen, N.J. All of the Westing- 350 West 4th Street, New York 14, 20 controls. No octopus should have N.Y. any trouble learning how to adjust house key field service personnel his color receiver! The fine tuning took part in classroom and laboratory sessions. Subjects covered in- COLOR ISN'T ALL-A recent knob, an often neglected control Comedy Hour show was telecast in with modern tuners, will become cluded:the study of color; com- posite color signals and their func- color. A follow-up of New York TV more important.Relatively minor columnists who viewed the program deviations in receiver tuning may tion; transmitter requirements and variables; basic receiver design; and on color sets produced interesting suppress the 3.58 me color subcar- adjustment of color receivers. results. When the show lagged, rier, seriously affecting color repro- bored reviewers tuned out the pic- duction. In switching from one chan- BUFFALOwas chosen by Syl- ture-in favor of B & W programs nel showing a color program to an- vania for its first color service school that held greater interest.

40 TECHNICIAN February, 1954 SHOP HINTS Minimizing Damage; Accident Prevention; Dynamic Condenser Check; Deodorizing Sets; Painless Chassis Carry.

Preventing Instrument Damage Gimmick for Chassis Carry burned areas by spraying two coats of plastic spray (Krylon) over the Plastic or wood cases of various Sometimes the edges of a heavy discolored areas. The smell disap- test meters are so smooth that the TV chassis dig into the hands when peared. Do you have a customer al- instruments are easily pulled from the chassis must be carried any lergic to odors of burned transform- the bench during use. A few layers great distance. I got around this by ers, resistors, and selenium rectifi- of adhesive tape placed on' the bot- making two cushions for my hands. ers? Try this method, it works!- tom of the case will often remedy B. 0. Riis, Miami, Florida. thiskindoftrouble.Tapealso may be installedin a criss-cross Dynamic Condenser Check manner to further prevent slipping. -H. Leeper, Canton, Ohio. Inmanyinstances,condensers short only under load, and check ok Safety Glass Removal when out of the circuit. When such If you have ever had to take out a condition seems to be present, I a safety glass to clean a dirty pic- use a voltmeter in series with the ture tube, and found to your horror suspect part, as shown in the illus- you had chipped or broken the glass tration. If the capacitor is shorted, a with a screw -driver, you will ap- de currentflows throughitand preciate this time and money saver. Grips made from an ed rubber hose help take through the resistance of the meter. Iuse a suction -cup dart from a the pain out of carrying a heavy TV chassis. child's toy gun. Simply moisten the rubber(afterremovingscrews These were made by cutting two which hold the glass)and press 5 -in. pieces from a rubber garden the cup onto the top center of the hose. The units were sliced length- glass(see illustration). Pull out - wise down the middle on one side. When slipped over the bottom edge of a chassis on either side, they tend to make good soft grips. They take very little room in the service kit and can beslippedoffand on in a second.-H. A. Wahl, Redondo Checking capacitor dynamically with voltmeter. Beach, Calif. This sets up an IR drop, and the Truck Accident Prevention meter needle will swing up, verify- Several of our men were involved ing the existence of the short. -J. L. inaccidentsas they opened the Mancini, Winthrop, Mass. doors of their service cars or trucks. This happened when approaching Chassis Supports motorists ran into the truck doors Large C clamps make ideal chassis in the dark. We solved this problem supports. They take up little room, by attaching narrow strips of readjust to many sizes of chassis, are flecting tape just inside each door inexpensive, and they may often be along the edge. When the doors are opened at night, the tape is visible to oncoming autoists, and accidents 'C" CLAMPS arethusavoided.-H.J.Miller, BOTTOM OF CHASSIS Sarasota, Florida. Deodorizing Receivers

Simple method for removing crt safety glass. It may sound strange, but some receivers havetobedeodorized. ward, at the same time holding the Thiswriterhadto replacea bottom of the glass with your free burned -out power transformer. The hand. job turned out quite well, except Note: This works equally well with that the customer objected to the safety glasses that swing out from burnt odor that persisted despite a thebottom. On thesepressthe thorough clean-up attempt. Finally used where other chassis supports rubber onto the bottom center, and I hit on a very simple method that cannot be employed. Much time can hold the top with the free hand, really worked. Reasoning that even be saved by their use, and needless pulling outward on the suction cup. a perfume does not smell when damage avoided.foseph Amorose, -J. L. Mancini, Winthrop, Mass. properlycorked,I corkedthe Richmond, Va.

TECHNICIAN February, 1954 41 New Antennas and UHF, VHF and Combination Units; Mounting Aids

Fretco UHF -VHF ANTENNA easily. List price, $6.95. Television for fringe -area UHF use, the array The Mi Tee Ray Screen, model Hardware Mfg. Co., Rockford, Ill.- is pre -assembled for rapid installa- MR S,is said to have high gain TECHNICfAN tion and may be easily added to ex- from Channels 2 to 83. A 50:1 front- isting VHF antennas. Light weight, to -back ratio provides discrimina- Bogen UHF ANTENNA WIRE This single -wire transmission line =MIMEO is said to have low loss, low inter- II..rrmil__ 1111111:4MaTio1111MMI ferencesusceptibility,all-weather 1111111011111R"Il%iliam performance characteristics, and low 11WrAIONINIMINI il Ina IIMIZONIMIIII radiation. Since swinging of line does MEM GEMr 1.1111.11MIN MI MIUMr= not affect signal, only two standoffs IM MEM MMIIIII with no intermediate supports are MI NEM. ME 11111111 IM UM. M necessary.Twomatchingunits MIMEO _w1=INIIII ra: °X'a J0111..11.11 ("Launchers") are required per in- ...01111152r=11 stallation, one each at antenna and ME I= LA MM receiver,tomatchtotheshort IIMINIMMEI INI1=111M111 =MI 1111111111=IN lengths of 300 -ohm line used at these MINN ME NMI ends. The wire, called G -Line,is MIN III NM III available in 150 -ft. length, in kit with 2 launchers and 2standoffs;list, $38.25. Wire alone available on 500- ft. reel for $32.50. David Bogen Co., 29 Ninth Ave., New York 14, NY- TECHNICIAN tionagainstghosts.Insulatorsof high dielectric strength prevent sig- Telkor UHF ANTENNA nalloss.Constructionwithstands wind and ice. Antenna comes pre- Engineered for high gain on all assembled but collapsed. List price, UHF channels, model14283dis- $7.25.Fretco,Inc.,406 N. Craig criminates against ghosts and inter- St., Pittsburgh 13, Pennsylvania.- ference, has a high front -to -back TECHNICIAN ratio, and is recommended for all- rugged construction and negligible weather use. Terminals are located wind resistance are also featured. infree space to reduce leakage. Telrex, Inc., Asbury Park, N.J.- Telco UHF -VHF DOUBLE V Shipped pre -assembled.Suggested TECHNICIAN This stack -type antenna, cat. no. list price, $8.50. For extreme fringe 9010, can be used for UHF, VHF locations, order stacking kit 14283K. Falcon VHF ANTENNA or both in primary and secondary Telkor, Inc., Elyria, Ohio.-TECH- The Falcon 88, a conical-yagi type signal areas. Adjusts to anglespac- NICIAN antenna for all -channel VHF use, is said to provide good line match, Safety LADDER BELT sharp directivity, high forward gain Dangerous falls from ladders dur- and absence of minor loberesponse. ing antenna installation are said to The array feeds into a single 300- be averted by this climber's safety ohm line. Quick assembly, sturdy device. One end of chain fastens to climber; the other end slides along rail fastened to ladder as climber goes up. If climber slips, device is said to lock against rail within 7 in. of spot where fall begins. Unit designed to be jam -proof, operate in all weather, and adapt to all types of ladders. Safety Tower Ladder Com- pany, P.O. Box 1052, Burbank, Calif. -TECHNICIAN

Telrex UHF ANTENNA ings of 50, 70, or 90 degrees, and has Model84 UHF, asingle -unit, construction and low cost are also highdirectivity.Ruggedlycon- conical -V beam, 4 -bay array, is said featured. Phasing bars available for structed to withstand wind, ice and to give 2 to 6 db more gain than stacking.FalconElectronicsCo., snow, the antenna is said to install conventional 2 -bay units. Designed Quincy, Illinois.-TECHNICIAN

42 TECHNICIAN February, 1954 Related Products and Hardware; Boosters, Tuners and Filters

Drake UHF TVI FILTER ation at the antenna input. Maxi- Anchor UHF -VHF TUNER Designedespeciallyforusein mum attenuation is provided on the The TV 900 tuner is a 12 -position UHF reception,the UHF -300 -HP low band, minimum on the high turret tuner for which individual high-pass filter attenuates interfer- band,withoutupsettingantenna - channel segments are available sep- ence caused by images and spurious receiver impedance match. No con - arately. Any group of 1 to 12 chan- signals from VHF stations, oscilla- nels, UHF, VHF or a combination torsofother televisionreceivers of both, may be installed in any and UHF converters, signals at in- sequence to meet the needs of a termediate frequencies, and others particular location. Original installa- in the region below 450 mc. List 1.1.411111. tionorreplacementofchannel price$3.25.R. EOULIZER L. Drake Co.,11 AUTOMATIC segments is said to be rapid and to SIGNAL Longworth Street, Dayton 2, Ohio. ATTE A Oit require no specialprocedures or -TECHNICIAN OM 40 4, test equipment. No extra crystals or 111601. converter strips needed on UHF. SIC TVI FILTER Single conversion principle is used High-passfiltermodel HP2 is on Channels 2 to 83. Anchor Radio made to pass all UHF channels from Corp., 2215 South St. Louis Ave., antenna to receiver with less than Chicago 23, Ill.-TECHNICIAN 1 db attenuation, but to provide 45 to 50 db of rejection for VHF sig- trols or switches need be manip- JFD ANTENNA ACCESSORIES nals. Eliminates many types of TVI ulated. List price, $4.95. Tele-Matic The Pal stand-off, for all types of peculiar to the UHF range, includ- Industries, Inc., One Joralemon St., antenna wires, avoids the use of a ing interference from Channel 5 or Brooklyn, N.Y.-TECHNICIAN metal ring surrounding the lead-in. HP TELESCOPIC MASTS This measure prevents development of standing waves, which may inter- Zip Up telescoping mast kits are fere with TV reception in sensitive available in heavy-duty sets(16 - gauge) or economy sets, to make installations. Lightning arrestor masts in sizes of 20, 30, 40 and 50 model AT120, the Lightning Sentry, feet.Individual mast sections are 10 in. long. Snug fit prevents wobble. Kits furnished with accessories including guy rings and bolts. Haydon Products Corp., 1801 Eighth Ave., Brooklyn 15, N.Y.-TECHNICIAN Insuline STAND-OFF 6 signals on double -conversion UHF systems.Service Instruments Co., Made to accommodate all types of 422 S. Dearborn St., Chicago, Ill.- standard TV transmission lines, this TECHNICIAN strap -type stand-off uses a low -loss includes a resistor network and two polyethylene grommet and features replaceable fuses. The network by- Bogen UHF BOOSTER an adjustable strap to mount on any passes interfering static charges as pipe diameter from 3/4 in. to 11/2 in. Model UHB booster provides gain well as lightning. The replaceable of 8 to 131/2 db across UHF band, fusesprotectthearrestoritself channels 14 to 83 inclusive. Noise against damage by strong lightning figure varies from 11 to 15 db. The charges. List price, $4.75. JFD Mfg. tuning knob is the only control, as Co., 6101 16th Ave., Brooklyn 4, the booster is turned on and off by N. Y.-TECHNICIAN a relay operated by the TV receiver. List price, $41. David Bogen Co., 29 Imperial GUY WIRE Ninth Avenue, New York 14, N.Y. This guy wire is made of 7 strands -TECHNICIAN of18 -gauge pure aluminum and TeleMatic SIGNAL EQUALIZER uses a closely -knit twist for added strength. Wire is guaranteed against The Automatic Signal Equalizer, rust, tarnish and salt -air deteriora- model AT -25, is intended for location. Stretch yield is approx. 3%. tionswhere low -frequency VHF Packaged in 100 -ft. continuous coils, channels may be strong enough to It is quickly tightened in place with 1000 -ft. cartons and 1000 -ft. metal overload the receiver, whereas high a captive tension nut. Insuline Corp. spools. Imperial Radar & Wire Corp., frequency channels are not strong of America, Long Island City, New 820 E. 233rd Street, Bronx 66, N.Y. enough to permit constant attenu- York.-TECHNICIAN -TECHNICIAN

TECHNICIAN February, 1954 43 TV Technician Test Instruments and Accessories; Storage Equipment

ASD TUBE CHECKER tion of America, 3602 35th Ave., GI SMALL PARTS CABINETS Long IslandCity, Model TV -20, a time -saving tube N. Y.-TECH- ThelineofSee-Thru NICIAN drawer checker, uses 20 connected sockets cabinets has been developedfor to facilitate testing. Developed par- Scala DEMODULATOR PROBE visible filing and storage of small ticularly for TV servicers, the check- partsinservice shops and home er needs no rollchart, minimizes A voltage -doublingcrystalde- workshops. The spill -proof drawers modulator probe for use with scope are made of clear guaranteed plas- or vtvm in TV alignment and trou- tic;welded bleshooting, the BZ-4 probe provides all -steelcabinets are increased utilityin signal tracing low-level i-f stages, and incali- brating generators against crystal - oscillator harmonics. A high degree %lirfit VTIP Vitt of 60 -cycle hum rejection permits 1 ItTriiilitin effective tests in heater, age, and de supplylinesforthe presenceof .19La spurioushigh -frequencyvoltages. Can be used to localize dead or weak :1,17:111,` IFT1114 i-f stages, calibrate the base line of a scope, demodulate a video -amplifier sweep response curve, check the set-up procedure and features port- output of a sweep generator, and to ability. Other characteristics: auto- test for sync -buzz pulses in a 4.5-mc. matic line compensation, high sensi- used.Adjustable drawer dividers tivity to leakage, positive gas de- and identification labels are protection circuit. Net price, $124.50. vided. Models available with from AmericanScientificDevelopment 8 to 128 drawers, with extra -size or Co., P.O. Box 104, Fort Atkinson, metal drawers, and with carrying Wisconsin.-TECHNICIAN handles forportability. Over 750 combinations can be supplied to suit Insuline TEST LEADS user's requirements. General Indus- trial Co., 5738 N. Elston Ave., Chi- This pair of leads, intended for sound channel. Useful to 150 mc. cago 30, Ill.-TECHNICIAN use with standard test instruments, Priced at $10.75, complete with coax- has heavy lucite handles 5 in. long ial lead and instruction book. Scala Windsor TUBE CADDY and %-in. in diameter. The leads Radio Co., 2814 19th St., San Fran- Although this fold -out caddy, the furnish protection against high ac cisco, Calif.-TECHNICIAN and dc voltages. The ends are fitted Carry -All, is built for portability, it Superex CRT TEST ADAPTER provides space for meters and other withsmallchuckswhichtake tools necessary in on -the -spot home phonograph -needle test tips, useful Designed for use with any make servicing, as well as for tubes. The forprobing crowded connections tube tester and all picture tubes, caddy may be obtained free on a and piercinginsulationofwires this adapter features simplicity of without damage. Handles are col- operation. One end plugs into the ored red and black,respectively, tube checker. The other end con- nects to the crt, which need not be removed from cabinet. Price, $3.95. Superex Electron. Corp., 23 Atherton St.,Yonkers, N.Y.-TECHNICIAN RCP HV PROBE The HVMP-2 high -voltage multiplier probe lead extends the range ofthe manufacturer's model 655 peak -to -peak vtvm on dc volts. Me- ter scale readings are multiplied by 100 with the probe. Complete with multiplier resistor and terminations, the probe is of the heavy-duty type tube purchase deal, or bought out- and carry 45 -in. lengths of flexible with asafetybarrier.Pricedat right ($14.95). Further details from leadswith moldedright-angle $8.95. Radio City Products Co., Inc., Windsor Electronic Tube Co., 1515 phone -tipplugs.Catalog number, 152 West 25 St., New York, N.Y.- Sheepshead Bay Road, Brooklyn 35, 304; price, $1.65. Insuline Corpora- TECHNICIAN New York.-TECHNICIAN

44 TECHNICIAN February, 1954 New Components Parts for Initial Use andReplacement; Shop Aids

Int'l SELENIUM RECTIFIERS IRC POWER RESISTORS Halldorson FLYBACK Type PW-7 and PW-10 power re- Flyback transformer FB412 is de- Special -type selenium stacks, de- sistors, rated at 7 and 10 watts re- signed as an exact replacement for signed for the anticipated power sup- spectively, are useful in many radio Part No. C-201-21025-1 in 84 models ply requirements of color TV re- and chassisofAirline, Raytheon ceivers, are available for capacitive and TV applications. Type PW-7 loads of 600, 700 and 750 ma. Maxi- available from.51to 5100 ohms, and Truetone TV receivers. The unit to 8200 features a variable -gap width con- mum input voltage ratings are 130, PW-10 available from 1 172 and 195 volts rms. Special con- ohms;tolerances,5% and10%. trol, tapped agc winding and a spe- Manufacturer's ratings show favor- cialmountingbase. Halldorson struction affords lower forward drop, able performance with respect to hu- Transformer Co., 4500 Ravenswood lower temperature rise and longer midity, load life, overload and ef- Ave., Chicago 40, Ill.-TECHNICIAN life.InternationalRectifierCorp., fects of soldering. International Re- El Segundo. Calif.-TECHNICIAN sistance Co., 401 N. Broad St., Phila- Stancor FLYBACKS EFCON CAPACITORS delphia 8, Penna.-TECHNICIAN These four flyback transformers Type MH plastic film capacitors for Philco receivers are exact re- feature special design for close toler- GE SOCKET WRENCH SET placements, according to the manu- ance, miniature size, moisture resist- This space -saving socket wrench facturer.A-8220replacesPhilco ance, high insulation resistance and set has been developed for radio - part 32-8565, used in 14 models and TV servicetechnicians. The two chassis; A-8221 replaces 32-8555 in tools, each with four heads mounted 29 models and chassis; A-8222 re- in the shape of a cross, replace 8 places 32-8533 and 32-8534 in38 sets; and A-8223 replaces 32-8572 in 15 sets. All chassis involved were manufactured in 1952 and 1953. The replacement units have choke coils, resistors, and capacitors wired to the terminal boards. Three exact -replacement flyback transformerscover 91 Motorola low dielectric absorption. Available models using 52 chassis. Stancor part in tolerances of ±1%, ±-2%, ±5% number A-8224 replaces Motorola and voltage ratings of 200, 400 and flybacks24C711265,24C711265 -A, 600 v dc in any value from .01 to 1 and 24C721290 in 56 models. A-8225 mfd. Hermetically sealed in metal replaces 24K712193 in 15 models. tubular cases. Electronic Fabricators, A-8226replaces 24K721301C and Inc., 682 Broadway, New York 12, 24K271517C in 20 models. Each unit N.Y.-TECHNICIAN has a horizontal centering pot, vari- Sprague CAPACITORS, PC's able gap width control and a socket individual hex -head wrenches. Replacement ceramiccapacitors Made of chrome -plated hardened for a 1B3 rectifier. Added to the original design are a corona ring on and Bulplate printed circuits are be- steel; sizes clearly marked. Avail- ing furnished in clear molded poly- able through GE tube distributors. the tube socket and a reinforced terminal board to withstand the strain styrene boxes. The re -usable con- Tube Dept., General Electric Co., tainers reveal both contents and rat- Syracuse, N.Y.-TECHNICIAN of inserting or removing the 1B3 tube. Chicago Standard Transformer ings of units at a glance. Snap locks Corporation, Standard Division, Ad- on the hinged lids eliminate spilling. Daven ATTENUATORS dison and Elston, Chicago 18, Illi- These compact boxes are space sav- Series 154 fixed attenuator pads nois.-TECHNICIAN ers for storing small parts. Sprague are available in either T orbalanced Products Co., Marshall St., North H networks. Units are available in Adams, Mass.-TECHNICIAN Jet PRECISION CONTROLS losses up to 100 db with a wide No -Noise CONTACT SPRAYER range of input or output impedances. Jet D-100 precision potentiome- Maximum power dissipation, 1 watt; ters are available with rotation up to No -Noise contact and volume con- Accuracy, ±2%. Common applica- 360 degrees, and in resistance ranges trolcleaneris now being made tions:to equalize incoming signal up to 50,000 ohms, =L-1%. Units are available in spill -proof 6 -oz. pres- levels, to change impedance, to com- rated at 1 watt. Other features: light sure spray cans, for service techni- bine 2 or more incoming lines into a weight, long life, high ambient tem- cians who find this type of container single line, or to equalize the outputs perature rating. Anticipated life is more convenient. The cleaner is also of several speakers connected to a said to be in excess of 1 million cy- available in 2 -oz. and 8 -oz. bottles, common source. Daven Co.,191, cles of noise -free operation. Jet Elec- and quart cans. Electronic Chemical Central Ave., Newark, N. J.-TECH- tronics, Inc., 93 Mass. Ave., Boston, Corp., 813 Communipaw Ave., Jer- NICIAN Mass.-TECHNICIAN sey City 4, N.J.-TECHNICIAN

45 TECHNICIAN February, 1954 Tubes and TubeEquivalents

Radio and TV Types; CRT's, CrystalDiodes and Transistors

Sylvania 12 -VOLT amplification of 37 db. Raytheon Mfg. larger picture tubes with 90 -degree CAR RADIO TUBES Co., Receiving Tube Div., 55 Chapel deflection angles. Glass shell type; In line with the trend toward 12- St., Newton 58, Mass.-TECHNI- socket and basing arrangement iden- voltautomobilebatteries,afull CIAN ticalto that of 6W4-GT damper. complement of 12 -volt tubes is avail- RCA 6BY6, CRYSTAL DIODES The all -glass 12ZP4-A rectangular able for use in parallel -heater cir- crt is designed for magnetic focus cuits in automobile radios. Except for The 6BY6 isa 7 -pin miniature and deflection. Features filterglass filament ratings, they are equivalent pentagrid amplifierfor use asa faceplate, takes single -field magnet to their 6 -volt prototypes; e.g., the gated amplifier in TV receivers, es- ion trap. RCA Tube Department, 12BA6 is similar to the 6BA6,r -f pecially as a combined sync separa- Harrison, N. J.-TECHNICIAN or i-f amplifier. Others in the line: tor and clipper. 12BD6, r -f amplifier; 12BE6, con- Six types of crystal diodes, ger- CBS21FP4C verter; 12AV6, 2nd detector and au- manium point -contact type, are of This aluminum -backed, sealed -in -glass construction: 1N34 -A all -glass, dio amplifier; 12X4, rectifier. Audio rectangularcrtuseslow -voltage output tubes include the 12AQ5 and electrostatic focus, electromagnetic 12V6GT. Sylvania Electric Products, SOCKET CONNECTIONS deflection, a grey -glass cylindrical Inc., 1740 Broadway, New York 19, faceplate and a single -field ion -trap N. Y.-TECHNICIAN Bottom View magnet. Outer conductive coating, when grounded, may be usedas hv Sylvania POWER AMPLIFIER filtercapacitor. Typical hv value, Beam power amplifier 6CM6, in- 14kv. CBS-Hytron, Danvers, Mass. G2 -TECHNICIAN tended for use as a vertical deflec- 64 tion amplifier in tv receivers, and also as a class A, audio output tube. CBS BEAM -POWER AMPLIFIER This 9 -pin miniature type has pin G3 A directreplacementforthe connecti6ns as follows: pin 1, screen 6BQ6-GT, said to be more ruggedly grid; pin 2, no connection; pins 3 designed for longer life andopera- and 6, control grid; pins 4 and 5, tion beyond the limits of the 6BQ6, is heaters; pin 7, cathode; pin 8, no PIN1: GRID No.1 the 6CU6. Intended foruse in connection; pin9,plate. Sylvania PIN2: CATHODE, GRID No.5 horizontal output stages, as wellas Electric Products, Inc., 1740 Broad- PIN3: HEATER in audio -amplifier and class Cr -f way, New York 19, N. Y.-TECH- PIN4: HEATER applications. Socket, plate cap and NICIAN PIN 5: PLATE basing arrangement follow the 6BQ6. PIN6: GRID NO.2, GRID No.4 CBS-Hytron, Danvers, Mass.- Sylvania 6AM8 PIN 7: GRID NO.3 TECHNICIAN This 9 -pin miniature typeisa GE 6BJ7, CRT's combined diode and pentode. Pen- -general-purpose type intended for tode section is similar to 6CB6; di- low -power rectification as in isolat- Type 6BJ7 is a miniature triple- ode section similar to one half of ing, clipping, and switching circuits. diode, designed for use in color TV 6AL5. May be used as final i-f am- IN38-A-large-signal type useful in receivers to reduce tube comple- plifier and video detector to reduce clampingcircuits. ments. May be used as dc restorer IN54-A-high- forthreesignal tube complement. Sylvania Electric back-resistance type intendedfor channels.Each Products Inc., 1740 Broadway, New diode section is similar to diodesec- York 19, N.Y.-TECHNICIAN clipping circuits, high -impedance hv tion of conventional 6AL5. probes, dc restorers, and high -im- 21ACP4 and 21ACP4-A (alumi- Raytheon TUBES, GERMANIUMS pedance detectors. 1N55-A-large- signal type with high peak inverse nized) are all -glass rectangular crt Thefollowing miniaturetubes voltage rating. EApecially useful in types using 90 -degree horizontal de- have been designed primarily for TV clamping circuits, dc restorers and flection angles. Wider angle makes applications: 6CF6-sharp cutoff hv probes. 1N56-A-high-conduction possible reduction of overall length pentode for use in gain -controlled i-f type useful as limiter in FM cir- to 20 in., reducing size of cabinet stages or as UHF r -f amplifier; 6CS6 cuits.1N58-A-similar to1N55 -A required for receiver. Typical 2nd -dual -control heptode for use as but with a lower peak inverse rat- anode voltage: 16kv. General Elec- sync clipper. ing. Tube Department, Radio Corp., tric Tube Department, Schenectady Germanium diodes are now avail- of America, Harrison, N.J.-TECH- 5, N.Y.-TECHNICIAN ablein hermetically -sealed types, NICIAN with optional plug-in construction. CORRECTION Ruggedly built for shock resistance. RCA CRT and DAMPER Author Kesgen writes in to say that Low -noise PNP junction transis- P-1, in his article, Audible Alarm for Type 6AU4-GT, a half -wave rec- Servicing Interatittents (Jan. '54 TECH- tor, type CK727, has an average noise tifier,isdesignedforuseasa NICIAN), should have been listed as factor of 13 db, and an average power damper diodeinreceiversusing 10 meg, not 1 meg.

46 TECHNICIAN February, 1954 Audio and Hi-FiItems Speakers, Enclosures, Amplifiers and Allied Units

W -Z TV HEARING AID Utah HI Fl SPEAKER SYSTEMS Webcor TAPE RECORDER This auxiliary speaker, specially One single -speaker and several Following the success ofits 3 - designed forthe hard -of -hearing, multiple -speaker systems are avail- speaker phonograph, Webstor-Chi- permits TV viewing at normal dis- able as follows: model HF100, 12 -in. cago is producing a 3 -speaker tape tances from the receiver without speaker and cabinet, response from recorder, model 2030, to give wide- loss of sound. Leads from the aux- 30 to 10,000 CPS; model HF300, 10 -in. angle dispersion of sound throughout woofer plus tweeters in cabinet, re- the listening area. One 4 -in. and two sponse from 30 to 15,000 CPS; Quar- 6 -in. speakers are used to disperse tet model, 12 -in. woofer plus tweet- sound so that high -frequency dead ers in corner enclosure, response spots are avoided. Construction of from 30 to15,500 CPS:Chordette one-half inch wood veneers lowers model, 8 -in. woofer plus tweeter in cabinet resonance, thus improving bookshelf or end -tableenclosure. bass response. List, $143.70. Webster - UtahRadioProductsCo.,Inc., Chicago, 5610 W. Bloomingdale Ave., Huntington, Ind.-TECHNICIAN Chicago 39, Ill.-TECHNICIAN Brook HI-FI AMPLIFIER Masco TAPE RECORDERS A small -size single -chassis ampli- Models 53 and 53R (with and with- fier and controlunit, model 22A iliary speaker clip to the leads from out radio) are dual speed, dual track provides response within 1 db from main speaker. Auxiliary unit may tape recorders featuring fast for- 20 to 20,000 cps with 10 watt output be hooked over shoulder of listener ward and rewind speeds and two - at negligible distortion. Five input or back of chair. Price, $13. Wright - motor drive. Response at 7.5 in. per channels are featured for tuners, Zimmerman, New Brighton, Minne- second: 80 to 8500 cps, with wow and TV, recorder and phono cartridge; sota.-TECHNICIAN flutter less thon 0.3%; response at four output impedances from 2 to 3.75 ips, 80 to 5000 cps. Inputs for 16 ohms. Controls: channel selector, mike, radio, and phono; outputs for record equalizer (6 positions), bass, Cabinart SPEAKER HORN KITS external amplifier or speaker. Tim- treble, compensated loudness, and ing indicators, push-button operation on -offpower.BrookElectronics, Kits incorporating the Klipsch cor- and monitoring switch are also pro- ner -horn enclosure design are avail- Inc.,34 DeHart Place,Elizabeth, vided. Mark Simpson Mfg. Co., 32- N.J.-TECHNICIAN able in unfinished birch. The com- 28 49th Street, Long Island City 3, pact cabinets achieve large -enclo- N. Y.-TECHNICIAN sure performance on low frequencies Scott HI-FI CONTROLUNIT by using back -loading to increase Model 121-A Dynaural Equalizer - path length. Kits K-12 and K-15, for Lorenz WOOFER and TWEETER Preamplifier is a self -powered re- 12 -in. and 15 -in. speakers, respec- The Lorenz woofer and tweeter mote control unit for broadcast or tively, each provide an extra port for are designed to be used in combina- home sound systems. Record com- mounting a tweeter or other auxili- tion for a wide -range speaker sys- pensation is provided by separate, ary speaker. Kits include hardware, tem. Also available are a high-pass continuously -variable bass turnover pre-cut baffle, and instructions for filter to match the two speaker units and treble roll -off controls. Built-in assembly andfinishing.G. & H and a choice of cabinets to house Dynaural Noise Suppressor dynami- Wood Products Co., 75 North 11th thethree components comprising cally discriminates against turntable N. Y.-TECHNICIAN the system. Kingdom Products Ltd., rumble and recordscratchwith 23 Park Place, New York 7, N.Y.- minimum effect on musical frequen- TECHNICIAN cies. Also featured: Variable high - Kloss SPEAKER SYSTEM frequency cut-offfilters,separate This small -size complete speaker Craftsmen HI Fl FM TUNER bass and treble tone controls, 8 - system makes high-fidelity performance possible at a low cost; based on An FM tuner said to meet the high- theoriginal Baruch -Lang design. est Hi Fi requirements, model C900 Employing four 5 -in. speakers in a features high sensitivity and stability wedge-shaped housing little more with low distortion. Some features: than a foot high and less than 20 in. sensitivity of 1 microvolt for 20 db wide, the system may be mounted quieting; amplified,continuously anywhere on the floor or ceiling or variable AFC for optimum control of in the corner between two walls. strong and weak signals; less than Corner -mounting is not essential for .05% intermodulation distortion wide range and low distortion. Avail- through entire receiver. Three con- position input selector, and separate able in output impedance of 4 or 16 trols are provided: AFc, off -on -vol- input levelcontrols. Compensated ohms. May be obtained direct from ume, and tuning. Net price, $99.00. loudness control may be switched to manufacturer for $19.95. Kloss In- The Radio Craftsmen, Inc., 4401 N. operate as flat volume control. H. H. dustries,10 Arrow Street, Cam- Ravenswood, Chicago 40, Ill.- Scott, Inc., 385 Putnam Ave., Cam- bridge, Mass.-TECHNICIAN TECHNICIAN bridge 39, Mass.-TECHNICIAN

TECHNICIAN February, 1954 47 Technician's Lighter Side

Obscure ThreatDept. Joe Thomas, one ofour service friends, was telling us how he col- lectedsomelongoverduebills. Customers to whom Joe had mailed strings of letters, some gentle and others stern and purposeful, had blandly ignoredtherequestsfor immediate payment. Several hundred dollars was involved, and Joe was not disposed to overlook the check forthis sum in 48 hours, matter. further. Thoughts of the raise that you'll be surprised at what'll hap- seemed imminent weaved through One day a man came around and pen. offered to collect the his mind like 60 -cycle hum. sums due, in Yours truly, etc. "Infact,"concludedtheboss, return for a percentage of the take. We don't recommend the tech- "you're getting so popular with the "Fine," said Joe. "You collect, and nique, but it does point up the value customers,in a few months you I'll pay you 20% of the totalyou of a fresh approach to one's prob- might be able to start a business of bring in." lems. . Within 3 days, checks adding your own, and take them all away up . .. so I'm forced to fire you." to $280, or about 90% of themoney Reward of Virtue owed Joe Thomas, were received in (1 80 Degrees Outof Phase) the mail. A small-town radio shopowner- Think and Grow Poor Joe was curious about his collec- let's call him Mac-calledone of his You probably never heard about tor's technique. technicians into his little office for the owner of a large TV -radio shop "Tell me, whatever didyou do a heart-to-heart talk the other day. who was much impressed with the that made that money roll inso "You know, the customers like numeroussignsmarked THINK fast?" he asked, when he had paid you very much," said Mac. that he saw in the plush front offices the man his $56. "Thank you," beamed the techni- of a factory he was visiting. Some "Just wrote 'em a letter," replied cian. the collector. time later, the merchant decided to "Practically every customer install similar signs in his ownes- "One letter?" asked Joe. "I wrote you've visited in the month you've tablishment. Several days after the them at least five letters! What did been here has had glowing things to signs had been posted in prominent your letter say?" say about you." parts of the store, a friend came in "I'll read ya one," said the collec- Thetechnician's beam became to visit. tor. He took a piece of paper out beam -powered. "How'd that plan of yours work of his pocket and read: "Theysayyoudowonderful out?" asked the friend. "You know, Dear Mr. Best: work. You're courteous, competent, thatideaof sticking up THINK You owe the Joe Thomas Radio and thoroughly reliable." signs all over?" Service $15. If you don't send ina The serviceman's smile expanded "Not so good," sighed the shop owner. "The first day they were up, three people who walked in with smallradiostheywantedfixed looked at the signs, thought amo- 111,0NIm*Vgame ment, then walked out again. The Tr, second day my chief serviceman told me that after thinking it over, he would like a partnership in the business. To top it all off, my land- lord came in today, and after glanc- ing at the signs,told me it was about time he raised my rent." Have you had any amusing ex- periences during the course of your servicingwork? Why notwrite them down and send them in? TECHNICIAN will pay $5 for acceptable anecdotes of this kind. Ad- dress Editor, Technician's Lighter kkik.104.404 Side, TECHNICIAN, Caldwell - Clements, Inc., 480 Lexington Ave., "This must be the house... N.Y. 17, N.Y. 48

TECHNICIAN February, 1954

INTRODUCING the greatest advance in Conical antennas ...it's the all -new WALSCO Imperial. Featuring a new "barrier disc" insulator with 2 inches of air space between the terminals to prevent shorts. Soot deposits, dirt, moisture, salt, etc., cannot affect this insulator. The WALSCO Imperial will therefore maintain lasting high gain performance anywhere, regardless of weather conditions. Contact surfaces and terminals will never rust or oxidize. Front end hardware is stainless steel to prevent corrosion losses permanently. Front end elements are pre -assembled to holding plates 11 which are fastened to WO the insulator with one wing nut. C6NICAl Less than 2 minutes to assemble. 1110111110161 Guaranteed lasting high gain on ail VHF channels

tit\ 1111 r.tr 11(1j_11 In itt 11 3602 Crenshaw Blvd., Los Angeles 16, Calif. model 114-068 CONICAL

69 me-channel 4 aVHF CONICAL antenna built to the Quality Standardsof 195 me-channel 10 Directivity patterns of the CONICAL are exceptionally clean. The strong major lobe AM indicates fine directivity. PHENoin

Now ready to join the fastest -growing and fastest-selling antenna line in the United States is a new AMPHENOL VHF antenna. Designed to supplement the fabulous INLINE* forVHF reception, the new CONICAL antenna will give true-picture reception in every VHF signal area: major, fringe andlong-distance. Gain and directivity have been engineeredto the high AMPHENOL

standards that have set the quality goal for theentire industry standard toned Folded Boole craftsmanship attention to the small but importantdetails make relerence the CONICAL another example` of AMPHENOL'Sfine antenna 2 work. (111111111.S AMPHENOL CONICALs are available in single,two and four bay models. The stacked modelsuse unique phasing harnesses for extra gain. The CONICALmay be obtained in packaging that contains all thenecessary stacking equipment or else the individual antenna may be purchasedone or two to a carton. In addition, the single bay CONICALis available in a complete antenna installation kit. All elements of the CONICALare constructed of sturdy, long-lasting seamless aluminum tubing- assuring rust -free years of top performance. Reissue U. S. Potent 23,273

High gain of the CONICAL is illustrated in the gain charts for single, two bay and four bay models. Measured in accordance with proposed RETMA standards, charts also show the desirable flatness of the gain.the

AMERICAN PHENOLIC CORPORATION chicago50,Illinois Keep Your EYESonProfits!

Now's the Time to Make the Service Department Pay

Too many dealers are willing to Remedy: Fire the hopeless drones, against those employees who "draw" operate their businesses on the pre- "re -sell" the good men, who may such supplies out of inventory.) mise that the service department is have fallen into bad habits, on the merelyafeederforsales,and necessity for doing a full day's work. Sloppy Buying: This can be put shouldn't be expected to show a Have someone lay out each man's into two categories:1. Overbuying, profit. job for the day, and plan outside call and 2. Underbuying. In the first in- Here and there, because of certain routes carefully. Be sure to keep men stance,carelessnessisusuallyto unusual conditions, the premise just busy when things are slow. They can blame for buying too much stock, or mentioned may be sound to the ex- clean up the shop, rearrange stock goingoverboardinordering too tent that a few dealers find it impos- etc., during these intervals. many slow -moving items. In the sec- sible to rack up profits on service ond case, hand-to-mouth purchasing work, some going in the red with still Sketchy Estimating: Almostall is usually alibied with the excuse that others managing to operate on a shops are called on to estimate a great the person responsible for this im- break-even basis. many of the repair jobs that come in. portant chore of buying is too busy. But it's a truly unusual case where Do you have arealistic,profit - Obviously, buying too heavily ties an owner is justifiedin. resigning slanted method for quoting? If you up good money in inventory, while himself to this state of affairs before use a hit-and-miss technique you'll buying in inadequate supply ties up he has explored every avenue of pos- get plenty of headaches. If you "for- too many jobs and discourages tech- sible profitable operation in his serv- get" how much you told Mrs. Jones nicians. Remedy: Resolve to buy ice department. that job would be, you may wind up more carefully, making "need" lists behind the eight -ball. If, for instance, which should be checked against TECHNICIAN'S editors have pre- you bill her for more than quoted, stock on shelves and in servicers' pared this article with a view toward you may lose her as a customer. On hands. pointing out a number of reasons why the other hand, "forgetting" may re- profits get devoured in many service sult in a loss to you. Remedy: Make Not Enough Customers: No service departments. The editors are also out a simple "estimating slip" on department head should be satisfied suggesting some remedies to help every job, or fill in the amount on a with the amount of businessit's those owners and managers who service order. Spend a little extra presently doing. The objective should want to eagle -eye their operations time trying to make an accurate esti- be to expand, to keep adding new in an all-out endeavor to make mate. It'll pay off. customers in order to prevent lulls in money. work, and to compete with what may Do theseconditions prevail in Inefficient Record -Keeping: Do you be an increased number of service your service department? lose money through failure to include set-ups coming into the field this all labor and parts on some jobs? year. Remedy: Advertise consist- Inadequate Charges: A most com- Does the department lose money ently, even if small space is used in mon reason for in -the -red operation. throughfailureofemployeesto directories and in newspapers. Use Remedy: Review your charging for- charge out all tubes, components or direct -mail pieces to solicit new cus- mula. Don't be afraid to ask fair time on some repairs? Do your bills tomers, and to keep your name be- prices for your work. go out promptly? Are collections fol- fore the old ones. The profit -minded lowed up efficiently, or are accounts dealer not only renders service-he Overboard Overhead: Do you have receivable allowed to die of old age sells it, too. shirkers or time -wasters on your in the ledgers? Remedy: If some or Start a clean slate, in this second payroll? Do you have too much help? all of the foregoing conditions exist month of the new year, and a firm How do you keep men busy during in your department, do something resolution to show profits from yom- slack periods-when the overhead about it! For instance, hire an ac- service and installation. Many dealers continues to roll along? Does someone countant (part time) to set up a good are making fine livings because they in authority assign the bench work system, and insist that every man in watch every penny, and chop out the and outside calls? Are outside calls your employ keep an account of time, dead wood. It can be done in almost routed efficiently in order to save tubes and other components. (Many every shop. Why not try to make time and cut down vehicle expense? shopscharge partsand material' more money in your business?

TECHNICIAN February, 1954 51 HOW TO WIN To win one of these 503 prizes all you hove to do is complete in 25 words or less "I like Pyramid capacitors because You fill in this statement on a Pyramid contest entry blank which can be obtained from any electronic parts jobber selling Pyramid capacitors. You have this entry blank coun- tersigned by your jobber or one of his sales- men and forward itto us attached to a Pyramid Dry Electrolytic Capacitor box top -the top being the part which carries the description of the item. There is no limit to the number of entries which you may make in this contest but each entry must be accom- panied by a box top. Full rules for the contest appear on the entry blank. It's so easy. Here is the kind of statement that might win: "I like Pyramid capacitors because they always check out perfectly and don't deteri- orate and so I know I won't have to call back at my expense." "I like Pyramid capacitors because the line is so complete that I can always get what I need and don't have to worry about an IN PRIZES off -brand capacitor." PYRAMID

ifeet(Jy

PYRAMID FEATURES: O Only one quality-the best at no pre- mium. All Pyramid capacitors are made of materials commanded by rigid military specifications. O All Pyramid capacitors are non -hygro- scopic. O Highest quality insulator material used in all production results in low leakage factor. O Exclusive non -contamination technique guarantees close tolerances and no deterioration. Peak performances for life. O Pyramid capacitors operate unchanged at ambient temperature of 85-centi- grade. PRIZES! O Designed by service technicians across the country for their requirements. O Individually packaged for protection. O Permanently legible, high visibility ratings on each item. 100% absolute electronic inspection be- $2000 -1st prize fore shipment. Pyramid is in its 10th year as a leading manufacturer of high -quality capacitors. - $500 2nd prize, $100-3rd prize O PYRAMID ELECTRIC COMPANY 100-$10 prizes, 400-$5 prizes 1445 HUDSON BOULEVARD NORTH BERGEN, N. J. SERVICE ASSN REPORTS

reputation for fair dealing and his Lynch RadioCo.,Ottumwa,Ia.; Calendar of Coming Events role as "emancipator of the radio - W. B. Smith, Sidles Co., Omaha, TV service profession." After the Neb.; Norman "Scotty" Cameron, testimonials, the president was pre- the Cameron Co., Rock Island, Ill. Feb. 4-6: The Audio Fair, Alexandria Hotel, Los Angeles, Calif. sented with a gift. (allthreein the Iowa -Nebraska In his own speech, Liebowitz asked Chapter);DennisJ.Hightower, Feb. 8-12: WesternWinter Radio -Tele- H&L Radio Supply Co., Fort Worth, vision & Appliance Market, Western for greater active support of the as- Mart, San Francisco, Calif. sociation by its members. He said, Tex. (North Texas); and Albert J. "You cannot continuously help peo- Kernerman, GlendaleElectronic Mar. 22-25:InstituteofRadio Engineers ple who will not help themselves." Supply Co., Detroit, Mich., as well National Convention, Waldorf-Astoria as Joseph F. Keese, Radio Supply & Hotel, New York. Exhibits, Kingsbridge The president -founder was encour- Armory, Bronx, New York. aged by the fact that he was getting Engineering Co., Inc., Detroit, Mich. more cooperation from more people The organization also reports that May 17-20: ElectronicParts Show, spon- in 1953 than in the two preceding itis currently engaged in revising soredbyAssociationofElectronic years. With the growth of associa- the 1953 NEDA Battery Index, with Parts & Equipment Manufacturers; West CoastElectronicManufacturers tions, he found the outlook for the the new edition expected early in Association; Radio -Electronic -Television service profession becoming brighter. 1954. Over 6500 copies of the index ManufacturersAssociationandNa- have been mailed out on past re- tionalElectronic Distributors Associa- quests, confirming a need for such a tion and Sales Managers Club (East- NEDA Grows cross-reference work. An increasing ern Group), Conrad Hilton Hotel, Chi- cago, Ill. According to the national office of numberofbatterymanufacurers the National Electronic Distributors are cooperating by including NEDA June 15-17: Radio - Electronic - Television Association, the following parts dis- battery numbers on charts, labels, Manufacturers Association Conven- tion, Palmer House, Chicago, Ill. tributors recently joined the organi- and cartons. Copies of the 1953 in- zation. Members are listed with re- dex are still available, in the mean- Sept. 30 -Oct. 2: High Fidelity Show, Inter- spective chapter affiliation: time, on request. Address National national Sight and Sound Exposition, Burton S. Phillips, Electronic Cen- Electronic Distributors Assoc., 228 Palmer House, Chicago, Ill. ter, Inc., Minneapolis, Minn. (Min- N. La Salle Street, Chicago 1, Ill. Oct. 13-16: The AudioFair,Hotel New nesota);HenryLynch,Friday - (Continued on page 67) Yorker, New York.

NATESA Award to GE The National Alliance of Televi- sion and Electronic Service Associa- tions, 5908 S. Troy St., Chicago, Ill., presented a fifth award to the GE Tube Department for its public relations program in behalf of the TV service industry. Bertram L. Lewis, eastern vice-president of NATESA, madethepresentation of the "Friends of Service Management" plaque to John T. Thompson, sales manager of the GE Tube Department. Frank J. Moch, Chicago president of NATESA, was present. The award cited GE for "outstanding service to TV service management in creating bettercustomerrelations."Other GE awards came from Associated Radio and Television Service Deal- ers of Columbus, Ohio; Federation GE's J.T. Thompson accepts plaque from B.L. Lewis, NATESA V.P., as pres. F. Moch watches. of Radio Servicemen's Associations of Philadelphia; and Radio Techni- cians Guild of Boston. WILL YOU HELP US? Service Association: Address

ARTSNY Fetes Liebowitz . By giving us the Manager or Recording name ofthe technical Secretary's Name: . Officers and directors of Associ- Phone: association to which ated Radio -TV Servicemen of New Your Name: York, 165 E. Broadway, their wives you belong? We'd like Your Address: and some friends surprised Max this information as part Liebowitz, ARTSNY president, with Please mail thefilled -out coupon to a testimonial dinner. Speakers ex- ofan editorialsurvey Associations Editor, TECHNICIAN, tolled Liebowitz' judgment in eval- which we're conducting. 480 Lexington Avenue, N.Y.C. 17, N.Y uating proposed licensing laws, his

TECHNICIAN February, 1954 "Tough Dog"Corner

Difficult Service Jobs Describedby Readers Intermittent Pix Pulling playedfine.Nopulling-justa darned good picture. It seemed im- The complaint was "picture snak- possible that the TV cabinet should ing" and increased contrast after cause the picture to pull, yet the sis, causing the resistor to over -heat the set was on for about forty-five picture "snaked" only when theset minutes. The symptoms seemed to was in the cabinet. and go up in value (sketch C). With indicateanagcdefect. the increaseinresistanceof the First,I I decided to leave the seton the video plate load resistor, the checkedalli-f,tuner,and agc floor for a while. The customer, who con- tubes. They checked ok. Next I trast would increase, and some of fortunately was a very understand- the video voltage would get into the pulled the chassis on the floor and ing person, asked if I could set the left the set on for what seemed like TV receiver right side sync, causing the picture to pull a long time, but it played ok. I did up for a horizontally.-F. Mattioli, Madison, while, so her son couldsee a pro- Wisconsin. not care to wait too long in thecus- gram he was interestedin. Upon tomer's home with the chassison turning the set in a right -side-up the floor, so I brought it to the shop. position-heretofore I had always had The Mysterious 6AG5 I set it up on the bench witha me- it on its side so that I could check ter on the agc line. The set played When I was called in to service all right for two days! voltages-the set started to pull. At this set in the owner's home, she in- first it was pulling justa little, but formed me that she had previously Icalled the customer andex- within an hour the set was pulling plained that the set was working badly and contrast had increased normally in the shop, and that I had noticeably. not found anything wrong with it. I tipped the set sideways for just TUBE SHIELD The customer requested that theset FOR 6AG5 an instant, in order to clip my vtvm HOLES DRILLED be brought back to her home. About IN SHIELD FOR -- on the agc line. The agc voltage was VENTILATION forty-five minutes after I returned normal! Next I placed the chassis theset,the customer called and between two chairs (see sketch A). complained of the same trouble.I This enabled me to check voltages told her to leave the set on, and I while the set was in an uprightpo- would be right over. iticn. After a considerable amount When I arrived, the set was pulling Holes punched in this tube shield prevented of checking I found that the trouble repeated tube breakage due to excessive heat. horizontally,althoughnotvery was caused by a 2.4k video plate badly. "The longeritison,the load resistor(see sketch B). The called several technicians in to re- worse it gets," the set owner com- resistor was badly charred, but only pair the receiver. About a week or mented. I shut off the set in order on one side-the side that was fac- so after they fixed it, the set would to pull the chassis out of the cabinet ing the chassis. When the set was in go bad again. The raster was ok, to check voltages. Then I put the thenormal uprightposition,the but there was no video. The owner set on the floor and turned it on. It heat would rise up against the chas- informed me that a tube in the back ofthesetwith a metalshield A-Set-up for checking the chassis in an upright position while horizontal pullingoccurred. around it (6AG5, 4th video i-f) had B-Schematic location of the overheating resistor in the videoamplifier plate circuit. C-Cut- away chassis view, showing how resistor overheating depended been found broken, and required upon the position of the chassis. replacement several times. Nobody, it seems, had been able to discover B+ why the tube was breaking repeat- OVERHEATED RESISTOR --\ edly. I looked, and sure enough the 2.4 K 6AG5 was broken again.

(A) 12BH7 I took the shield off and made VIDEO AMP small holes in it for air ventilation (see sketch) ; then I replaced it over a new tube. My reasoning was as TO SYNC SECTION follows: the ventilation would prevent the tube from getting too hot, expanding and finally breaking. The diagnosis was apparently (B) correct, 12BH7 since the set has been working for (VIDEO AMP) HEATRISES AGAINST CHASSIS, two months now without a coin- CANNOT ESCAPE FREELY plaint.-Gelman's TV, Philadelphia, Penna. DEFECTIVE CHASSIS CUTAWAY 2.4K RESISTOR Executive abilityisdeciding quickly (C) and getting somebody else to do the work. -J. C. Pollard 54 TECHNICIAN February, 1954 WITH THE

HIGH SENSITIVITY - WIDE RANGE 5" OSCILLOSCOPE PUSH-PULL VERTICAL AND HORIZONTAL AMPLIFIERS 20intoPER INCH "V" SENSITIVITY - 150 my PER INCH "H" SENSITIVITY

SERIES ES -500-A affords the ultimate in performance, visibility and operational flexibilityat moderate cost. PRECISION engineers have incorporated every necessary feature which they found to be required to meet the needs of the rapidly advancing art of electronics, A.M., F.M., and TV. SUMMARY OF IMPORTANT FEATURES * Push -Pull Vertical Amplifier - High Sensitivity. Wide Range, Voltage Regulated. 20 millivolts (.02v.) per inch deflection sensitivity. 10 cycles to 1 MC. response. 2 megohms input resistance. Approx. 22 mmf. input capacity. * Compensated Vertical Input Step Attenuator-Xl, X10, X100. * Direct Peak to Peak Voltage Checks thru use of internal, semi -square wave, regulated voltage calibrator. * Vertical Phase -Reversing Switch. Non -frequency discriminating. * Push -Pull, Extended Range. Horizontal Amplifier -150 Millivolts (.15 v.) per inch deflection sensitivity. 10 cycles to1 MC response at full gain. I/2 megohm, approx. 20 mmf. input. * Linear Multi -Vibrator Sweep Circuit -10 cycles to 30 KC. * Amplitude Controlled, Four Way Synch. Selection: Internal Positive, Internal Negative, External and Line. * "Z" Axis Modulation input facility for blanking, timing, etc. * Internal, Phasable 60 cycle Beam Blanking for elimination of alignment retrace; clean display of synch. pulses, etc. * Sweep Phasing Control for sinusoidal line sweep usage. * Direct Horizontal and Vertical Plate Connections. * High Intensity CR Patterns through use of adequate high voltage power supply with separate 2X2 rectifier. * TheCircuit and Tube Complement: 6C4 "V" cathode follower. 6CB6 "V" amplifier. 6C4 "V" inverter. Push -Pull 616's "V" driver. 7N7 "H" amplifier and inverter. Push -Pull 6AU6's "H" driver. 7N7 Multi - vibrator, linear sweep oscillator. 5Y3 low voltage rectifier. 2X2 high potential rectifier. VR-150 regulator. 5CP1/A CR Tube. * Four -Way, Lab -Type Input Terminals-Take banana plugs, phone tips, bare wire or spade lugs. Matches SP -5 Probe Set cable connector. * Light Shield and cross -ruled Mask, removable and rotatable. * Extra Heavy -Duty Construction and components. * Heavy Gauge. Etched -Anodized, No -Glare, Aluminum Panel. * Fully Licensed under Western Electric Co. patents. SeJtee4 ES5500,4: In louvered, black -ripple, heavy gauge steel case. Size 81/4- x 141/2" x 18". Complete with light shield, calibrating mask and comprehensive instruction manual ..NET PRICE $173.70

Series SP -5 - OSCILLOSCOPE TEST PROBE SET FOR TV SIGNAL TRACING, ALIGNMENT, TROUBLE SHOOTING AND WAVEFORM ANALYSIS * Specifically engineered for use with PRECISION Catnode Ray Oscilloscopes, Series ES -500 and ES -500A. * Includes four of the most important test probes for general purpose, as well cs specialized use: 1. HIGH IMPEDANCE-LOW CAPACITY PROBE 2. SIGNAL TRACING-CRYSTAL PROBE 3. RESISTIVE-ISOLATING PROBE 4. SHIELDED-DIRECT PROBE * Each probe s specifically engineered for efficient application to the special test prcbiems requiring its use. * Distinctively colored heads and individual IabellMg permit positive identification of each probe. * A single, universal, coaxial cable accommodates each probe through a quick -change, self -shielding connector. * A specially -designed, shielded plug provides for positive cable attachment to the ES -500 and ES -500A Verfical input posts. Seleut SP -5,in custom -designed, vinyl -plastic, carrying * Each probe head terminates in a patented clip -on tip which case, complete with four probe heads, universes coaxial cable, frees bath hands of the operator. and detailed operating instructions. NET PRICE $23.50

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TECHNICIAN February, 1954 55 Hi Fi Guide to Pickup Arms & Cartridges (Continued from page 30)

3/8' on the other hand, can withstand formance equal to, or better than, ORIGINAL OVERHANG wide variations without any ill ef- theoriginalcartridge.(When a fects. This is the mainreason that change -over is being made from one magnetic and ceramic units have type of pickup to another, anything longer lives. in the amplifier's input circuit that is Another characteristic worth con- intended for specific use with the /2 sidering is the cartridge's response to OVERHANG AFTER original type of cartridge may have IMPROPER REPLACEMENT vertical modulation. Such modula- to be altered or removed to match OF NEEDLE tion is the result of the cartridge the new unit. This applies to input translating the vertical movements impedance, as well as to preampli- Fig. 10-Overhang may be changed whena of the stylus into electrical signals. fiers,equalizers and compensating stylusreplacement is ofthewrongtype. Vertical modulation should be kept networks.-Ed.) at a minimum for high-fidelity re- the best investment from the user's production. The Stylus. Some of the informa- standpoint. Even though they cost Some pickups, such as the vari- tion provided on needle selection more initially, they are good for a able -reluctance and other magnetic couple of thousand playings on fine- types, are relatively insensitive to 78 RPM groove discs, whereas the saphire- verticalstylus movements. These NEEDLE tipped needle is good only for a few cartridges depend for their output hundred. Less distortion and less voltages on the transfer of flux from record wear isproduced by the the pickup cantilever (see Fig. 7) to 331/3 RPM diamond -point needle, and its life is the pole pieces of the coils. When the NEEDLE also longer. cantilever moves laterally, getting Needles should be checked peri- closer to one pole piece than the odically to see whether wear has de- other, proportional currents are in- veloped. Fig. 8B shows a worn needle duced in each coil, and an output point that will not track the grooves voltage is developed. When the can- properly, 78 thus introducing record tilever moves vertically, however, GROOVE 331/3 wear. A worn needle also introduces the distance between the cantilever GROOVE excessive needle -talk and distortion. and the pole pieces does not change, Magnifying lenses made for this pur- and no output voltage develops. Fig. 9-Improper tracking results when the pose should be used to thoroughly stylus diameter does not have the correct size with respect to the record grooves it rides on. inspect the needle tip. Choosing a Cartridge. As we can An unfortunate mistaketobe see, the various types of cartridges may seem to concern the set owner avoided by servicemen is the inter- have their advantages as well as more than the serviceman; the data changing of standardandLP theirdisadvantages. The typeof presented should, however, help the needles. The LP needle has a 1 -mil cartridge used is determined by the technician answer questions he may point; the standard needle has a budget. It does not pay, of course, to be asked. 3 -mil point. Fig. 9 illustrates the poor choose a cartridge that has a wider The prime function of the pickup seating that is produced when these frequency response than the ampli- needle (or stylus, as it is more ac- needles are interchanged. The LP fier with which it is used. curately called) is the transfer of the needle rests at the bottom of the Before a cartridge is replaced in a lateral movement of the record's standard groove and does not follow Hi Fi system, check its character- groovestothe pickupcartridge. lateral motion properly. This causes istics to see that it will give per- Diamond -point needles are probably an excessive amount of surface noise and distortion. The standard needle, on the other hand, rides too high in the LP groove and has, in consequence, a tendency to skip and wear the walls of the grooves. Another important factor in the replacement of a pickup needle that may be overlooked is its shape. If the wrong type of needle is used as a replacement, the pickup arm over- II hang may be changed considerably (see Fig. 10). PickupAssemblyReplacement Cautions. The various parts of the pickup arm assembly have definite requirements. When any part replacement is necessary, or an improvement in operationis desired, check the overall characteristics of the replacement against the charac- ,4111,444 A/ teristics of the associated elements in "It's intended to give the set owner a more intimate view of favorite performers." the system.

56 TECHNICIAN February, 1954 Du Mont Unveils New Dual -View TV Set A television receiver which shows two TV programs on one screen while permitting two audiences to view their choices simultaneously was introduced by Allen B. Du Mont Laboratories,Inc. The receiver is known as the "Du Mont Duoscopic." The receiver can tune in any two TV programs from any stations within range. This means a husband may view one program, while his wife watches another. A press gatheringatthe pre- view demonstration, using polaroid glasses, saw a particular program at one moment and then, by merely reversing the glasses, became ob- servers of a different telecast. With JOHN personalized ear pieces and conven- MILLER ient remote control audio units, the TELEVISION CO. "The Man Who press group heard and saw any of Knows" two programs they desired. When- ever an individual wishes, he can independentlyswitchtoanother TV ANTENNAS FOR ANY RECEPTIONCONDITION channel. The remote -control sound system makes possible audio syn- Why stock antennas from 10 manufacturers-when no chronization withthe channel matter what the reception problem,there's a Miller an- change. Audio volume can be low- tenna that does the job. WE OFFERTHE WORLD'S LARGEST ered or raised to accommodate the SELECTION OF TV ANTENNAS . you nameit, we have it. listener's preference. As the West's pioneer TV antennamanufacturer, builder of New Fields for Webcor one million antennas since1948, we guarantee you TOP Webcor, manufacturer of phono- QUALITY at a REALISTIC PRICE. graphs and magnetic recorders, to- dayentered two newindustries with the announcement of its first Compare this Value . . . this Price! radio and the first of a series of A Typical Miller Value musicalrecordings ontape.The CONICALKIT Conical Kit includes 10 element coni- new Webcor radio is a five -purpose cal, 6 -foot, 11/4" aluminum mast, base, clock -radio called the "Quintet." It 0 $975 guy ring, 30' of stranded, galvanized features a plug for attaching a tape steel guy wire, 50' of 300 ohm lead-in recorder to make recordings of ra- LIST line, mast stand-off, 3 wood stand-off insulators, 3screw eyes,instruction dio shows. It will also permit plug- sheet. Now priced at only $9.75 list. in of a record changer and will turn appliances on or off automatically. Pyramid Prize Contest A contest for servicemen that of- Write for fers $5600 in cash prizes has been announced by the Pyramid Electric Company of North Bergen,N.J.The contest will begin Feb. 1 and will FREE OATAI00 continueuntilthe end ofApril. First prize will be $2,000. The second and third prizes are $500 and $100, respectively. In addition, there will be 500 other cash awards. Thecontestentailscompleting ------Write for Free Catalog!-----_ the sentence, "I like Pyramid ca- MILLER TELEVISION CO. pacitors because . . ." in 25 words or 2840 Naomi, Burbank, Calif. Gives Complete Information on World's Largest Se'ection less. Entry blanks for the contest TELEVISION Co. will be available through jobbers, ofTV Antennas.GivesourRealisticPrices.JustOff who will countersign each one sub- Press. Write for Your Free Copy Today! mitted. Duplicateawardswill be Name granted to the lucky jobbers whose servicemen win prizes. Each entry 2840 NAOMI Company in the competition must be accom- BURBANK, CALIF. Addre s

panied by the top of a box from a City State . Pyramid dry electrolytic capacitor. Rockwell 9-1659 37 TECHNICIAN February, 1954 SERVICE MEN HAVE NO WORRIES Mfrs. Changes Recent Design Alterations

Linearity Improvement in '54 Crosley Sets Several of the changes that have been made in Cros- ley's custom and deluxe line of 17 in. and 21 in. television receivers to improve horizontal linearity are described below (see schematic). The code letters usedon chassis incorporating this change are also given. Chassis with earlier code letters do not have the change. 402 CODE E 404-1 CODE C 402-1CODE F 404-5 CODE B 402-4CODE B 405 CODE D 402-5CODE A 405-1 CODE D 403 CODE E 410-1 CODE B 403-1CODE D

Although the published parts lists still apply to early production chassis, the following list gives the new parts used in the chassis incorporating this change. The symbol numbers are given in two columns to permit quick reference to the schematic in either bulletin.

SYMBOL INCORPORATED NUMBER PRIOR TO CHANGE IN CHANGE

BulletinBulletin No. 459No. 465Part No. Description Part No. Description C159 C161 137499-34Capacitor, 560 144675-2Capacitor, .005 mmf., 10%, mmf., 500 v., 500 v., Mica Disc Ceramic C162 C163 154988 Capacitor, 120 157046-1Capacitor, 100 mmf., 10%, mmf., 10%. 3KV., Disc 3KV., Disc Ceramic Ceramic R172 R182 39374-55 Resistor, 300,00039374-57Resistor, 470,000 ohm, 10%, ohm, 10%, Tung -Sol works harder to make Tung- 34 watt 34 watt Sol tubes better. That pays off in fewer service call-backs. Horizontal Instability in Stewart -Warner Sets If you encounter critical horizontal hold action on any current Stewart -Warner TV receivers, it is suggested that you specifically follow the procedure we are going TUNG-SOL® to outline. By so doing, you will be able to obtain horizontal holding action that remains within the range of dependable the front panel hold control. 1. Check to see thatcon- denser 131 is a silver mica unit, 820 mmfd, ±5% toler- PICTURE TUBES ance. This condenser is Stewart -Warner part No. 512,- 547. It is already incorporated in all receivers except TUNG-SOL ELECTRIC INC., Newark 4, N. J. Sales Offices: Atlanta, those 9300 series sets that do not include the letter "H" Chicago, Columbus, Culver City(LosAngeles),Dallas,Denver, in the series coding at the rear of the chassis. 2. Check Detroit, Newark, Seattle. to see that condenser 130 is other than a Sangamo type

58 TECHNICIAN February, 1954 ...WHEN CUSTOMERS HAVENO in TV Sets COMPLAINTS in Television Receivers

(red body). This .01 mfd condenser should be the type supplied under Stewart -Warner part No. 512311-do not use a substitute. The correct type is already incorporated in all (except the 9300 series) that do not include the letter "R" in the series coding on the rear of the chassis. 3. If the receiver has a "horizontal range" trimmer condenser, it should be screwed closed. 4. If a 6SN7GTA tube is used as the horizontal afc-blocking oscillator, replace it with a 6SN7GT. 5. Turn the receiver on and allow it to operate for fifteen minutes. 6. Set the horizontal hold control on the front of the receiver to its counter -clockwise position. 7. Remove the 6BE6 gated sync separator tube from its socket. This will cause the receiver to lose both horizontal and vertical sync. 8. If it was necessary to replace the No. 130 .01 condenser (step 2) you will probably find the receiver to be pretty far off horizontal frequency. This should be corrected by adjusting the bottom slug of the Synchroguide transformer until the picture "hunts" horizontally. In other words, the picture will remain intact and slide from side to side across the screen, but will not break into diagonal lines. If you did not replace the .01 condenser, the bottom slug of the Synchroguide transformer should not be adjusted. In this case, only the top slug need be adjusted until the hunting condition is obtained. 9. Plug the 6BE6 tube back into the socket and set the front control of the receiver to the center of its range. The picture should now remain in horizontal sync when switching channels and also remain within the range of the horizontal hold control. Sentinel TV Receiver Changes To eliminate possibility of drive lines appearing on picture, and to reduce effect on size of horizontal hold coil adjustments, make the following change (in Models 454, 455, 456, 457, 464, 465, 466, 500, 511, 512, 513, 515, 520, 521, 522, 523 and 525) : Replace C-58 (a 680 mmfd fixed mica capacitor, at plate of horizontal oscillator) with a 470 mmfd fixed mica capacitor, -4-100, part no. 23E3500-40. To increase vertical size and vertical linearity control range in models 532, 542, 554, 562 and 564: If R-106 (a 270 -ohm 1 watt resistor) is connected to the output side of the filter choke, connect it to the input side of the filter choke instead. This can be done Tung -Sol never lets up on keeping simply by removing the 270 ohm 1 watt resistor from its physical position on the tie lug located in center of quality up. That's why customers make chassis, and connecting this resistor across the C-84 input fewer complaints about Tung -Sol tubes. filter condenser sections -40 mfd (half moon) and 40 mfd (square). Vertical Line in Emerson 27 -in. Sets A vertical white line may appear in the picture on some TUNG-SOL® 27 -in. sets (chassis 120179-B, 120205-B) due to overdrive of the horizontal output tube. In the event that readjust- dependable ment of the horizontal width coil, changing the 6BQ6 horizontal output tube or changing the 6W4GT damper tube does not eliminate this overdrive bar, change the RECEIVING TUBES value of R-74 from 330k 1/2 watt to 390k 1/2 watt. This resistor is connected to pin no. 5 of the 6SN7 horizontal TUNG-SOL makes All -Glass Sealed Beam Lamps, Miniature Lamps, Signal oscillator. 120179-B chassis incorporating this change are Flashers, Picture Tubes, Radio, TV cnd Special Purpose Electron Tubes coded Triangle C; 120205-B chassis, Triangle B. and Semiconductor Products.

59 TECHNICIAN February, 1954 ofitemscovered.AudioGuide, pages,isavailablefrom Arrow MFRS' Catalogs & Catalog T-54, 128 pages, is available Audio Center, 65 Cortlandt Street, from Terminal Radio Corporation, New York 7, N. Y. Bulletins 85 Cortlandt Street, New York 7, Understanding High Fidelity is a N. Y. High Fidelity Sound Equip- two-part, 50 -page booklet the first ment 1954, 58 pages, Hi-Fi, Audio Catalogs isavailable part of which attempts to explain from Hudson Radio and Television the how and why of quality repro- Five recently published catalogs Corp., 48 West 48th Street, New duction in the home. The roles of present comprehensive listingsof York 36, N. Y. 1954 High Fidelity, the various parts of the system are audioand Hi-Fi equipment and Audio Equipment, 96 pages, is avail- discussed. The second part is a guide components for use in the home and able from Sun Radio & Electronics to the selection and installation of on the professional level. Amplifiers, Co., 650 Sixth Avenue, New York components. An appendix includes speakers, tape recorders, equipment 11, N. Y. High Fidelity Music Sys- a glossary of Hi-Fi terms and a housingsandenclosures,micro- tem Components, Catalog No. 454, bibliography. Price, 25 cents. Avail- phones,recordplayers,pickups, 48 pages, is available from Lafayette able from David Bogen Co., 29 Ninth tuners, audio test equipment and Radio, 100 Sixth Avenue, New York Ave., New York 14, N. Y. binaural gear are some of the types 13, N. Y. 1954 Audio Handbook, 104 Mail Order Catalogs Recentlypublishedmailorder catalogs listing electronic equipment and components, replacement parts and associated gear are available from Radio Shack Corporation and Newark ElectricCompany. Both catalogs are fully indexed and illustrated, and cover test equipment, audio and amateur gear, batteries, tubes,relays,books,connectors, wires, switches, power supplies, replacement resistors,inductors and capacitors. In addition to the main productindex,the Radio Shack book has a manufacturer's index. Both catalogs include order forms and instructions for ordering. Radio FLAT RESPONSE ON COLOR 7'7 FASTER EASIER RADIO'S more MASTER PROFITABLE NEW! 1954 operation EDITION

BRACH #555 1370 pages $10.56 LIST PRICE Over 85,000 items GET INTO THE Over 8,000 illus. MASTER HABIT! Completely indexed

$1.95at your parts distributor. Publisher's price $6.50 Have complete access to the many thousands HIGH GAIN VHF-UHF of products vitalto your daily sales and service operations. Inthecustomer'shome,acrossthe ON ONE ANTENNA. counter or on the bench, you'll value the Master's thoroughly complete descriptions, specs, illustrations and prices . . . allsystematically organizedin NO MIXERS NO COUPLERS NO INTERACTION 18 big sections for instant reference. Increase your sales . . . sell directly from the Master. Facilitate your stock problem . . . use the Master for jiffy STOPS FM INTERFERENCE comparison ofallelectronic products. The Master is the only Official Buying Guide for the TV -Radio- Electronics industry.It contains unabridged catalog FREE!Technical Bulletin data direct from the manufacturers. For buying and selling-the Master gives you all the needed facts "SOLVING THE COLOR - ina single volume. Over 100,000 in active daily u e. Get into the Master BLACK & WHITE TV, VHF/UHF habit. Order your copy today! RECEPTION PROBLEM" Just few of the products by IRA KA.4AEN. Included: Tubes - Test BRACH #556 Equipment-Tools-Trans- formers - Capacitors - Eliminate $22.62 LIST PRICE Resistors - Relays - Coils - Attennas - Recording & Incomplete PA Systems - Hardware - Small Transmitters - Receivers - Catalogs and Loose Dlr. of General Iron" Corp. Kits- Wire - Cable. . . and thousandsof allied Literature 200 Certral Avenue Newark 3, N. J. products I HUmboldt 2-1500 UNITED CATALOG PUB, INC. 110 LA3AYITTR RT., NOW YORK 13, N. Y.

60 TECHNICIAN February, 1954 Shack Catalog 54, 226 pages, is avail- phia, Pa., covering their new five - This 20 -page cataloglists, by set able from Radio Shack Corporation, channel community antenna system. manufacturerandpartnumber, 167 Washington Street, Boston8, This new engineering development equivalent Miller replacements for Mass. Newark Catalog No. 56, 194 uses the present Jerrold series W chokes, coils and transformers used pages, available from Newark Elec- equipmentwhichdistributes TV in video and sound i-f, r -f, discrim- tric Company, 223 West Madison signals from three stations. New K inator, sync and sweep circuits; also Street, Chicago 6, Ill. series equipment is added to dis- listed are peaking coils, ion traps tribute two extra channels. The new and adjustable inductivecontrols. Federal Selenium Handbook catalogfolder,titled"Jerrold's J. W. Miller Co., 5917 South Main Design, application, specifications Five -Channel Community Antenna Street, Los Angeles 3, Calif. System," is available upon request. and circuitry are covered in the sec- CRT Comparison Wall Chart ond edition of Federal's Selenium Miller Coil Replacement Guide RectifierHandbook. The80 -page The TV Picture Tube Division of booklet lists selenium rectifiers for The latest Miller TV Technician's Sylvania Electric Products Inc. has radio and TV applications, and also Coil Replacement Guide, No. 154, released a new version of its handy covers rectifier designs and power isavailable through leading parts supply circuits for use with audio distributors throughout the country. (Continued on page 62) amplifier, radio, and intercom systems, as well as other dc power supplies. Servicing information includes troubleshooting tables to help the technician in checking selenium rec- The new RCP tifiers for specific troubles, as well as diagrams for setting up rectifier tests in the repair shop. Price, 50 FLYBACKER cents. Available through distributors, or write to Federal Telephone and Radio Company, 100 Kingsland Road, Clifton, New Jersey. Model 123 Jerrold Folder on Community TV Antennas oval, A catalog folder has been issued by Jerrold Electronics Corporation, $39.75 26th & Dickinson Streets, Philadel- The Answer To Fast, Reli- ofFlyback ableTesting Transformers and Yokes

5761°-**NEWS** Quickly... Accurately ... Checks the Horizontal Out- put Circuit of All TV Re- ceivers

It Extremely sensitive, the Model 123relays, etc., where the impedance is REPLACEMENT Flybacker immediately shows up a not relatively low. In fact the instru- single shorted turn in a flyback trans- ment may be used as a proportional BANDING KITS former or yoke. Its light, portableAC Ohmmeter. design serves to advantage in the KIT "C": ( Consists of ) shop and in the home. 2-12'x 3/4" STAINLESS STEEL STRAPS So Easy to Operate! with eyebolts attached All tests can be carried out with the 2-Eyebolts Unattached components in place in the TV re- Minimum of connections necessary. 4 - Nuts to Fit Eyebolts ceiver. Call-backs can be preventedAll you do is remove flyback plate 2-KWIK KLIP Strapping Fasteners by checking all flyback transformers caps-set switches-apply leads and and yokes in stock for opens, shorts, then read meter. The slightest change Also available, KIT "A", similar to etc. Flybacker tests are also appli- in inductance due to a shorted turn or KIT "C", except furnished with 3/4" cable to inductive windings on anythe effect of intermittents shows up wide GALVANIZED steel banding. transformer, choke speaker, solenoid, on the meter immediately as "BAD." Universal- may be used with any chimney antenna mount. In Can.: A. T. R. Armstrong Co.. Toronto See the RCP Flybacker at your parts -distributor, or write Dept.T9 for further information. SOUTH RIVER METAL PRODUCTS CO., INC. SOUTH RIVER, N. J. RADIO CITY PRODUCTS CO., INC. P` PIONEER AND OUTSTANDING PRODUCER 152 WEST 25th ST NEW YORK I.N.Y. rt, FINESTLINE OF ANTEPP/1 '.10';NTS

61 TECHNICIAN February, 1954 tion angles, basings, and length -in - Blonder -Tongue Laboratories, Inc., Catalogs & Bulletins inches data on all tubes are also 526-536 North Avenue, Westfield, included. New Jersey. (Continued from page 61) B -T TV Calculator Blonder -Tongue Labs is offering RMS UHF Antenna Bulletin "TVPictureTubeComparison a free "TV Calculator" to TV serv- Indoor and outdoor UHF antennas Chart." The new free wall chart, ice dealers and TV technicians. The including yagis, bow ties and corner brought up to date, can be obtained calculator contains a scale for instant reflectors, are described in a six - from the Sylvania Advertising Dis- conversionof decibelstovoltage pagebulletin.Alsocoveredare tributionDepartment,1100 Main gain;chartsanddiagramsde- lightning arrestors and other acces- Street, Buffalo, N. Y. Data on more scribing various strengths of attenu- sories for UHF installations. Obtain than160differentcrttypesis ator pads; a convenient channel - copies direct from Radio Merchan- available at a glance. Added infor- megacycle scale,and atableto diseSales,Inc.,2016Bronxdale mational features in this new chart compute TV transmission line losses Ave., New York 62, N.Y. include ion trap listings and base at VHF and UHF channel frequen- diagrams. Face, body, focus, deflec- cies.Availableonrequestfrom EICO Instrument Catalog The 1954 EICO Catalog lists and illustrates the complete line of EICO instruments obtainable in kit form (30items)orfactory -wired(33 items).The12 -pagebooklet,in additiontoshowingeachitem, breaksdata down intofeatures, specifications and applicationsfor TECH -MASTER every listing, thus providing easy reference. Available free to TECH- custom-Littii.014-TV CHASSIS NICIAN readersfrom Electronic InstrumentCo.,Inc.,84Withers Are A Credit to Your Skill... Street, Brooklyn 11, New York. RMS Antenna Catalog when you do a job on Catalog No.55,32pages,de- scribesthemanufacturer'scom- a custom, installation plete line of antennas and accessories.Fully indexed by product When you've been commissioned to do your best groupings, the catalog includes in- ... when you're being paid for the finest ... that's the time to formation on packaging and ship- remember that TECH -MASTER backs your skill with the finest line pingweights. A gainreference of custom-built TV chassis in the field. chart is also present. The booklet is The custom installation field offers a vast poten- 3 -hole punched for easy filing in tial for expansion and profit! binders. It can be obtained from One satisfactory installation is a valuable rec- RMS, 2016 Bronxdale Ave., New ommendation for another and another! York 62, N. Y. Say you saw it in TECH -MASTER TV CHASSIS are specifically de- TECHNICIAN. signed and built for custom installations! The finest components and the finest craftsman- CBS Advertising Aids ship assure years of fine performance! Four new business builders are SO - when your customer wants custom installation - give being offered by CBS-Hytron to him custom quality with service -dealers to help them tie in TECH -MASTER GOLD MEDAL SERIES with the nationally advertised Cer- tifiedQualityServiceprogram. Quality TV Chassis for Custom Installation These CQS sales aids are: An illu- MODEL 2430: Latest, improved 630 type circuit; minated plexiglass sign for indoor for picture tubes up to 24". Audio connec- use, a metal flange sign, direct -mail tion for optional use of external amplifier. postal cards, and ad mats. All four Net Price (Less Kine) $189.50 salesaidsareavailablethrough MODEL 2431: Same as 2430, but with true fidel- CBS-Hytron distributors. The illu- ity, Push -Pull audio amplifier. Net Price minated sign is intended to serve as (Less Kine) $199.50 a night light, as well as a display for MODEL 2439: For new 90s kinescopes, (24" rectangular, 27" and 30"). daytime use. Net Price (Less Kine) $262.50 The postal cards offer copy tying in with the Life -Post advertising on At All Leading Radio Parts Distributors Certified Quality Service. They are printed on government postals, with the dealer's own three -line imprint, and are available at a nominal cost. The ad mats are purposely small, so TECH -MASTER PRODUCTS CO. Rrite for Detailed Data that a service -dealer can afford to 445 BROADWAY, NEW YORK 13, N. Y. use them over and over. The mats MAKERS OF CUSTOM-BUILT TV CHASSIS, QUALITY TV KITS AND HIGH FIDELITYAUDIO EQUIPMENT may be obtained free.

62 TECHNICIAN February, 1954 a new champion! NEW BOOKS

PRACTICAL COLORTELEVI- 416% SION FOR THE SERVICE INDUS- 7>,) TRY. Published by RCA Service Company, Inc., Camden, New Jer- sey. 64 pages; $2.00, paper bound. This profusely illustrated"first" in color -TV books (100 illustrations, many in full color) covers its subject in three sections. Section I be- CA. gins with color principles, and in- cludesdefinitionsof many new terms the service technician will be confronted with. The visible color SPEAKERS spectrumisalsoanalyzedand broken down with respect to primary colors. The development of the transmitted color signal is next ex- amined in detail. An overall consid- eration of the compatible TV color system is then presented, followed by a study of the three -gun color C -D's Cub tube. Section II begins with a basic circuit description of a typical color TYPE receiver, and follows up with a de- 2°8S2 tops in the tailed section -by -section analysis. The third section, largest in the field of book,offerspracticalinformation for service and installation. Infor- molded tubular mation on test equipment and alignment is presented, as well as in- capacitors structions to be given to the customer. Appendices to the nook include a glossary of the many new termsthatwillenterthetech- nician's vocabulary, a bibliography, and a complete schematic (fold -out insert)of the receiver on which * Outperforms all other molded tu- the book is based. Full -color photo- bulars in humidity tests! graphs of pictures seen on the crt fiiiArof superior * Stands up under temperatures up screen during various conditions of to 100°C. defective operation and misadjust- speaker performance * You get more for your dollar with ment are very striking, and should thispremium tubulardesigned prove most helpful to the technician. especially for replacement needs, HAVE YOUTRIED one of the with "better -than -the-original" performance! HOW TO TROUBLESHOOT A TV new RCA Gold Label Speakers? * Ask your C -D jobber about the RECEIVER, by J. Richard Johnson. Your customers will be im- special "Cub -Kit"! Published by John F. Rider, Inc., pressed by the improvement For the name of your C -D distrib- 480 Canal Street, New York 13, N.Y. made in their sets when you utor, see the yellow pages of your 128 pages; $1.80, paper bound. use these outstanding replace- phone book. Write for Catalog to: Some of the topics considered in ment speakers. Dept.RT24,Cornell-Dubilier Elec- this book are: getting the most out tric Corp., South Plainfield, N. .1. of TV service data; preliminary ob- CONSISTENTLY DEPENDABLE servations and checks-the troubleshooting approach; use of test pat- Now available from your near -by terns in troubleshooting; and inter- RCA Distributor. Look for the CORNELL- pretation of distortion in the picture gold label when you buy. or raster. Tubes, tools, equipment and accessories are dealt with from DUBILIER apracticalviewpoint.Tablesin CAPACITORS these sections are intended to guide There are more the novice technician in assembling C -D capacitors in (Continued on page 65) -use today than any other make. RADIO CORPORATION IN 110. PLAINIIILO. N.J., 111* 11100010.MORCESTIEN Be Sure to See Page 73 AND CAMBIUM. NW, PlIOVIDINCt AND HOPS LLLLLL . of AMERICA II., INDIANAPOLIS. IND.: SAMOS AND MOAT MINOS. CIRCUIT DIGESTS 1.C. 111.11$101111111*ADIA1T CONF.. . OHIO ELECTRONIC COMPONENTS HARRISON, N.J.

TECHNICIAN February, 1954 63 fourth step, do not repeat to get "just use in the 9300 series of Stewart - Rx for Ailing CRTs a little more" because, during oxida- Warner receivers? On these sets, no tion of the cathode powder several external focus control of any kind (Continued from page 39) microns of gas are released. On old is present. The focus of the tube is, tubes, the amount of getter material however, very much affectedby 1. Flash heater at 12.5 volts for 20 remaining may not be sufficient to the setting of the ion magnet-and seconds. absorb all the released gas.-Paul there is only one correct setting for 2. Age heaters at 7.5 volts for 5 Leichter, Philadelphia, Penna. this magnet. First, it should be ad- minutes. justedformaximumbrightness. 3. Repeat steps1 and2three Focusing Electrostatic CRT's Withinthisrangeof maximum times. The quality of the picture on any brightness, there is only one point of 4. Age for two hours at 6.3 volts, television receiver is to a large de- optimum focus. To obtain this point continuing to maintain B+ voltage gree determined by the sharpness of of best focus, adjust the brightness on the grid. focus of the electron beam. What level to normal with the brightness 5. Test the picture tube; repeat can be done to improve this focus- control, and set the tuner off chan- steps 1 to 4 if necessary. particularlyontheself -focusing nel. Observe the line structure of If emission is satisfactory after the (electrostatic)tubes, such as we the raster on the screen while making slight adjustments of the ion trap. You will find that there is one point at which the scanning lines appear most sharp. In obtaining this point of best focus, be sure that you do not reduce brightness. In the You name the event that good sharp focus cannot be obtained even after careful ion trap adjustment, it is suggested that the ion trap be reversed. To do this, slide it off of the tube, turn it over and slipit back on. The magnet should be placed diametrically op- posite its original position. By careful readjustment, you should now be able to obtain good, sharp focus.- (courtesy Stewart -Warner) Intermittent Pk The complaint was an intermittent picture on an Emerson Model 690B. Upon loss of picture, symptoms of poor acfiltering appeared-i.e.,a dark screen except for a 3 -in. band of white across it was present. By checking with a scope, I found video at the grid of the 6AC7 video amplifier, but none at the plate. Pulling the socket off the picture tube made the signal appear at the video am- plifierplate. The trouble was a cathode tofilament short inthe 19AP4 picture tube.-(courtesy Syl- G. I. has the phonomotor vania News) Single speed ... two speeds ... or three speeds ... there's no limi- tation on combination or type when you choose from General Servicer Runs for Congress Industries' broad line of phonomotors. Carroll S. Shaw, TV specialist, For example, shown above are two of General Industries' newest 5814 Hallandale Beach Boulevard, three -speed developments: Model SS, an extremely compact de- Hollywood, Fla., whose TV repair sign with 2 -pole motor; and Model DSS, with 4 -pole motor and shop on wheels was described in heavy-duty construction features for high fidelity reproduction. Nov.TECHNICIAN,writesusthat Both models incorporate the General Industries' unique, stepped - he has announced his candidacy for shaft drive principle which assures accurate reproduction and RepresentativeinCongress from trouble -free long life. Both contain an "OFF" position in which Florida. (Two years ago Mr. Shaw the idler wheel is released from contact with the turntable rim. was a candidate for the Florida state "OFF" position on Model DSS also cuts off current to motor. legislature.) Mr. Shaw also adds: For complete information, specifications, dimensions, and quan- "I am starting a weekly paper here tity -price quotations on these, or other phonomotors in the in Hollywood, and only hope I can famous Smooth Power line, write us today. make as much on it as I do in TV service. As I spend so much time doing service, I will not have time to THE GENERAL INDUSTRIES CO. campaign, so I am going to sell my DEPARTMENT MD ELYRIA, OHIO TV business. I hope I will not be sorry."

64 TECHNICIAN February, 1954 New Books BuiltfOr (Continued from page 63) INTERNAIONAL gERVICE RECTIFIER equipment and parts stock for vari- CORPORATION ous needs. Minimum essentials and optional additions appear in these lists. IL 5..41..0 CALKORNIA GUIDE TO AUDIO REPRODUC- TION, by David Fidelman. Pub- LIGHTNING lished by John F. Rider, Inc., 480 Canal Street, New York 13, N. Y. DIRECT 240 pages; $3.50, paper bound. REPLACEMENT For those who wish to acquire a oti background inthe principles and techniques of sound reproduction, RADI & TV but who are not and do not wish ARRESTERS to be audio specialists, this introduc- tory book should be of considerable Will accommodate Tubular, Oval, Selenium rectifiers Foam and Jacketed UHF Lines. Low - help. Not a layman's tract on Hi-Fi, capacitance design. Standing -wave the volume requires basic familiarity ratio approximately 2:1 at 800 Mc. Low with the principles and components loss ... approx. 1 db at 800 Mc. Screw ofelectroniccircuits.Beginning Type 234A1 ... Strap Type 235A1. with the theory of sound and musical instruments, the author proceeds to the design and construction of components of quality sound systems, and the assembly of complete systems. Theory of operation, prac- RCA tical circuits and networks, and en- - closure construction are considered. LIGHTNING Measurement techniques and servicing procedures are also included. Mathematicalconsiderations are UNIVERSAL simplified and kept to a minimum. MOUNTING ARRESTERS ITVRADID Weather -resistant ... continually dis- sipate static charges . . . do not S SERVICE LIBRARY unbalance line.. .easy to install. Mr. HERE IS LATE INFORMATION IN A Screw Type 215X1. . . Strap Type HANDY FORM FOR RADIO AND TELEVISION 214X1. REPAIRMEN, SERVICEMEN AND STUDENTS WIDER COPMZLIrity$AO. --r.tourf2 VOLS.$6 RANGE AUDELS T.V.-RADIO SERVICE LIBRARY- llighly Endorsed -1001 Facts-Over 1552 Pages - CA 625 Illustrations, Diagrams ttfParts. Presents Impor- tantSubjectsofModern Radio, Television, Indus- TV SET COUPLERS t vial Electronics, F.M.,Pub- tic Address Systems, Auto, Marine & Aircraft Radio, Phonograph Pick -Ups,etc. NOW AVAILABLE IT PAYS TO KNOW! The Basic Principles - AT YOUR Construction-Installation - Operation - Repairs - FAVORITE TroubleShooting.Shows How to get Sharp, Clear JOBBER T.V. Pictures. Install Aeri- als-How to Test. Explains Color Systems, Methods of permit operation of two or more TV Conversion, Terms, etc. In- sets from single antenna. Easy to includes Ultra High Fre- quency (11.H.F.)-Valu- stall ... no need to cut orsplice twin able for Quick Ready Ref- lead. Type 240A1. erence & Home Study. Tells How to Solve T.V. & Radio Troubles-Answers Your Questions. 9/'2ifre JRP-1 Get this Information for Yourself. 7 DAY TEST-ASK TO SEE IT! wr MAIL ORDER Fill all your replacement require- INTERNATIONAL RECTIFIER AUDEL, Publishers. 49 W. 23 St., N.Y. 10, N.Y. ments from one dependable source Mall AUDELS T. V. RADIO SERVICE LIBRARY 2 Vols. S6 on 7 days free trial. If O. K. I will remit SI in 7 days and S1 monthly ... your local RCA Distributor. C O R P O R A T ION until $6 is paid. Otherwise I will return them. 1521 E. Grand Ave., El Segundo, Calif I -hone: ORegon 8.6281 Name owRAD/0 CORPORATION CHICAGO: 205 W. Wackor Drive Phorne: Franklin 2-3889 NEW YORK: 501 ?Radio Pr Avenue Phone- Plaza 5-8665 Add Vik of AMERICA Occupation Employed by TC ELECTRONIC COMPONENTS HARRISON. N.J.

65 TECHNICIAN February, 1954 "Greatest Show onEarth"

Yes, the industry's greatest TV -electronic parts show will be held in two places simultaneously. Complete manufacturers' directory of - In CHICAGO, May 17-20, when parts, accessories and test equipment will have the spotlight at the Conrad Hilton products used by distributors Hotel. and service men - In TECHNICIAN, May issue, destined to be the Greatest Alphabetical listing of TV -Electronic Show on Paper. all manufacturers of Why the Greatest Show on Paper? Because the many ex- radio -TV -electronic clusive features planned for the May issue will surpass products anything that has been done by 0. H. Caldwell and M. Clements over the past 30 years. The Caldwell -Clements directories, color charts and special issues have always eclipsed anything attempted by publishers in this industry. In several respects, this TECHNICIAN Show on Paper will be more helpful than the show in Chicago, because: Exclusive annual distributors' directory 1-Many key men among the busy parts distributors will not be able to see the Chicago show, and can only READ about it. Complete 2-TECHNICIAN serves the CUSTOMERS of the parts distributors (the technicians and service managers) as well as the distribu- Representatives tors themselves. These technicians and service managers are directory also vitally interested in new developments but cannot attend the show. 3-TECHNICIAN'S 50,000 circulation includes more professional servicemen and service managers than any other service trade publication-actually over 45,000. PLAN NOW TO PUT YOUR MOST EFFECTIVE ADVERTISEMENTS IN Complete list of service TECHNICIAN associations TELEVISION . ELECTRONIC . 101,10 UDIO . SERVICE

Caldwell -Clements, Inc., 480 Lexington Avenue, New York 17, N.Y.

Yes, TECHNICIAN's May Issue will be the GREATESTSHOW ON PAPER

66 TECHNICIAN February, 1954 Ass'n. Reports

HAROLD J. - (Continued from page 53) (iv SCHULMAN LIETA Annual Report director of The Long Island Electronic Tech- service for nicians Association, 88 Fourth St., Oceanside, N.Y., organized in June of1953, has published its first annual report. Included in the paper oU are the program and policies of the MONt association,whichincorporatesa and chairman, code of ethics subscribed to by all service committee, LIETA members. The code covers TV DEFLECTION RETMA employment of qualified personnel says: forservicing,avoidanceoffalse COMPONENTS claims and false advertising, stand- ... a product as complex ard guarantees, use of quality reas a television placement parts in servicing, prompt cannot possibly be and efficient servicing and treatment maintained satisfactorily of customers in an equitable man- without timely, under- ner. standable and helpful In reporting on its other activities, LIETA discusses public service and service information. public relations programs, monthly "... itis only through the technical forums sponsored by the efforts of the experts in the association, its own employment ex- field, like yourself, that change, and its own technical library. servicemen can expect a On the agenda for future programs steady flow of alt -inclusive are service information. liability insurance and hospitali- TO RESTORE orig- zationbenefitsfor members, and inal performance, "We have found your education of the public to the tech- use original RCA publications to be nician's role in the community. TV Components consistency high ;n quality and integrity. ... used by lead- We particularly s ngle ing TV set manu- out your current Parts facturers who 11 Replacement Information recognize that program as a service RCA Deflection to the industry." Components set the engineering Rider *TEK-FILE-NOW, only standards in the industry ... and $1.50 per pack! 1 at your jobbers ) they cost no more! Try a pack. If you're nor satisfied, return the pack within 7 days anc your money will be refunded.

A VHF -UHF

* Dependable TV replacement parts Marker Generator listings starting with pack 57 and TV 10 Crystal controlled frequency coverage from 4.25 to 225 me JUST OUT! TV 12 on fundamentals -harmonic output on UHF. GET YOURS FROM YOUR Announcing .! Optically magnified screen permits most accurate LOCAL RCA DISTRIBUTOR RIDER RADIO MANUAL 23! marker setting. Outin February, Up-to-the-minute in- Write for technical details ... formation on all home AM, FM radios built during 1952 and 1953. THE HICKOK ELECTRICAL INSTRUMENT CO RADIO CORPORATION of AMERICA RIfin7PU3LISHER, INC. 10523 DUPONT AVE..CLEVELAND 8,OHIO JOHNF 460 Canal Street, New Seek 13, N. Y. ELECTRONIC COMPONENTS NARK/SON, N. J.

TECHNICIAN February, 1954 67 I 1111111111I w

RETAILED WITH A 5 -DAY MONEY BACK GUARANTEE

SNYDER MFG. CO., PHILADELPHIA 40, U.S.A BELLEVUE TUBE MILL, INC., PHILADELPHIA 40, U.S.A. SNYDER ANTENN-GINEERS LTD., TORONTO, CANADA WORLD EXPORT: ROBURN AGENCIES, INC., N. Y.

68 TECHNICIAN February, 1954 Complete Index of ALL "CIRCUIT DIGESTS" TO DATE Including Current Issue. CIRCUIT DIGEST NOS. 1 1 1to1 1 5 will be found in this Issue of TECHNICIAN

All Units Are TV Receivers Circuit Digest NI.. Circuit Digest No Unless Otherwise Noted Chassis 412: Models F-24CDMIL F-24CDBH, UHF -Tuner Model UHF -103 52 Chassis 412-1: Models F-24CDMU, F-24CDBU, "F" Chassis: Models 17C127, 21T14, 21C115, ADMIRAL Circuit Digest No. Chassis 416:Models F-27COMH, F-27COBH, 21C116, 210117, 21C119, 21C120, 21C121, 17T15, Chassis 416-1: Models F-27COMU, F-27COBU 21T10, 21T12, 21T4 84 Chassis 2242: Models 520M15, 520M16, 520M17. 106 Chassis 22A2A: Models 520M11, 520M12. Chas- UHF Tuner, Model S -UHF -80 104 sis 22M1: Models 121M10, 121M11A, 121M12A, Chassis"EE": Models21T7,21T8,21T20, 121M11, 121M12, 121K15A 121K16A, 121K17.A, DE WALD 21T21, 21C225, 21C226, 21C227, 21C228, 21C229, 121K15, 121K16, 121K17, 221K45A, 221K46A, Models ET -140R, DT -163R, DT -163A, ET -170, 21C230, 21C231, 21C232, 21C233 113 221K47A,221K45,221K46,221K47.Chassis ET -171, ET -172, ET -191, DT -190D 69 22Y1: Models 321M25A, 321M26A, 821M27A, 321M25, 321M26, 321M27, 421M15A, 421M16A, DU MONT 421M15,421M16,421M35,421M36,421M87, GRANCO Chassis RA -164: Model Clinton. Chassis RA - 521M15A, 521M16A, 521M17A, 521M15, 621M16, UHF Converter Model CTU 74 521M17 1 165:Models Beverly, Ridgewood, Shelburne, Chassis 19B1: Model 17DX10, 17DX11. Chas- Milford, Wakefield 3 sis 19C1: Model 121DX12, 121DX16, 221DX15, Chassis RA -166/167, 170/171: Models I7T350, 2210X16, 221DX17, 221DX26, 221DX38. Chassis 21T327, 21T828, 21T329, 21T859,21T366. HALLICRAFTERS 19F1A :Model 121DX11. Chassis 19H1: Model 21T376, 211'377, 21T378 51 222DX15 15 Chassis A1200D, K1200D or W1200D: Models Chassis RA -306, 307: Models Summit RA -306A1 1010P.1012P.Chassis D1200D, L1200Dor Chassis 22A3, 22A3Z: Models 122DX12, 222DX- & RA -307A1, Warren RA -806A2 & RA -807A2, X1200D: Models 1021P, 1026P. Chassis F1200D: 16B, 222DX16B, 222DX17B, 222UDX15, 2221J- Hampton RA -806A3 & RA307A3. Bristol RA - Model 1013C. Chassis 01200D: Models 1022C, DX16. 222UDX17, 222DX27B, 322DX16A, 322- 306A4 & RA807A4, Newport RA -806A6 & RA - 10270. Chassis U1200D: Model 1056C. Chassis UDXI6 101 :107A5, Rutland RA -306A6 & RA -307A6, Hart- TI2unD: Models 1051P, 10550, 1056C, 1060C, Chassis 20A2, 20A2Z, 20112 111 ford RA -306A7 & RA807A7, Sheffield RA -306A8 106IC. Chassis P1200D: Model 1052P. Chassis & RA -307A8,Westbrook RA -306A9 & RA - RI200D: Models 1053P, 1054P. Chassis P1200D: ANDREA 307A9,Windsor RA -306A10 & RA -307A10, Modds 1057C. 1062C. 1063C. Chassis ZI200D: Bradford RA -306A11 & RA -307A11. Warwick Model 1057U 21 Chassis VM21: Models T-VM21, C-VM21, 2C- RA-306Al2 & RA307Al2 107 VM21, CO-VM21 44 EMERSON Chassis A1300D: Model 1075 38 ARVIN Model TW-1000 World -Wide 8 -Band Portable Chassis 120166-D: Models 721D, 728D 10 Radio 49 Chassis TE331: Models 6175TM, 6179TM 13 Chassis 120168-D: Models 716F, 717F, 719F, Chassis A1400D: Models 21K201B, 21K211M, Chassis 337-341: Models 7210, 7212, 7214, 7216, 727D. Chassis 120169-B: Models 711F, 712F, 21K221B, 21K231M 102 7218, 7219 45 720D, 732B, 734B 31 Tv Dual Tuner, used in Chassis TE 330, 832, Chassis 120174-B: Models 752A, 755A. 784A; 340, 341 75 Chassis 120198-D: Models 711111r, 785C, 785E 91 Chassis TE 359: 9200 series 100 HOFFMAN Chassis 213: Models 21M903. 218904, 21P906 32 BENDIX ESPEY Chassis 408-24: Models 24M725, 24E3726, 24P727 513-C AM -FM Tuner 70 92 Chassis T14: Models 21K3, 21KD, 21T3, 21X8, OAK3 20 FADA Chassis T17: Models KS21C, TS21C, Chassis JACKSON T17-1: Model TS17C 50 The "Imperial"Series:Models17T6,17T9, Chassis 317A, 320A, 821A. 324A :Models 277. 1702, 17C4 25 217, 221-T, 321-C, 217-T, 317-C, 221-C, 62164 CAPEHART Models U2100C, U2150C,U2100T, UDL2100T, Chassis CX-36, RF-IF chassis coded R-3, De- UH21T 83 flectionchassiscoded D-4: Models 1T172M, 2C172M, 3C212M, 32212B, 4H212M, B, 5F212M, GENERAL ELECTRIC MAGNAVOX Model J.K-105 Series: CT331, 332, 333, 834. 6F212M, B, 7F212M, 8F212B, 9F212M, 12F272M, "Stratopower" chassis: Models 170125, 200107, 336, 336, 387, 338, 839, 340, 841, 842, 343, 844, 10W212114, 11W212M 17 21T1, 210208, 21C204, 21C201, 21C202, 21C214, 346, 346, 347, 348, 349 23 ChassisCX-37: Models 1T172MA, 1T172BA, 210206 4 3C212MA, 3C212MG, 3C212BA, 4H212MA, UHF Converter Tuner Model 700359 53 4H212BA, 5F212MA, 6F213B, 7F212MA, 8F212 - 107 Series: Chassis CT 358 65 BA. 9F212MA, 11W212MA, 1C213M, 2F218F. UHF Converter Tuner 696461 (700359Re- 3C213M, 4T213M, 4T213B, 5H218M, 8F21813 37 HOW TO FIND MONTH vised) 80 Chassis 108A series: Models CT, CU & CMU CBS -COLUMBIA in which any 401A; CT, CU & CMU 402A; CT, CU & CMU Chassis817:Model17T18,17M18, 17C18. CIRCUIT DIGEST APPEARED 403A; CT, CU & CMU 904A 112 Chasm. 820: Model 20T18, 20108, 20M28 14 Circuit DigestNumbers Chassis 1027: Models 27011, 27021 77 Sept. 1952 Chassis 750-3: Models 17M06, 22C06, 1- 8 MAJESTIC 22C38 9- 16 Oct. 1952 Chassis Series 110-111: Models 21T20, 21T21. 95 21030,21C31. 21D50,21D51, 21P60,21P61, 17- 24 Nov. 1952 21P62, 21P63, 21P70. 21P71 26 COLUMBIA RECORDS 25- 30 Dec. 1952 Chassis112:Models17T38,17T40,17T41, 360 Phono Amplifier 43 17C42,17C43:Chassis113:Models21T40, 31- 36 Jan. 1953 21T41, 21C42, 21C43 76 CROSLEY 37- 43 Feb. 1953 Chassis 380:Models EU17COM, EU-17TOB, Mar. 1953 EU-117TOM. Chassis 381: Models EU-21CDB, 44- 49 MALLORY EU-21CDM, EU-21CDN, EU-21C0Ba, EU-21- 50- 58 Apr. 1953 TV -101 UHF Converter 58 COMa 2 May 1953 VHF Chassis 392: Models EU-COMUa, 59- 64 21COBUa, 21CDMU, 21CDBU, 210DNU 65- 70 June 1953 MOTOROLA (Chassis 392 is very similar to the 880 -refer Chassis TS -292:Models 2101, 21C1B, 21F2, to Circuit Digest No. 2) 71- 76 July 1953 21F2B,21F3, 21F8B, 21K4, 21K4A, 21K4B Chassis388:Models EU-3000MU, 3000BU 77- 81 Aug. 1953 21K4W, 21K6, 21K5B, 21K6, 21K7. Chassis 33 TS -324: Models 21T4A, 21T4EA,21T5A, Chassis393:ModelsEU-21TOLU,EU-21- 82- 88 Sept. 1953 21T6BA 9 TOLBU. Chassis394:Models EU-21COLU, 89- 94 Oct. 1953 Models TC-101, TC-101B UHF Converters 59 EU-21COLBU 46 Auto Radio Mopar Models 610T 72 Chassis 402: Models F-17TOLH, F-17TOLBH: 95-100 Nov. 1953 Chassis 403: Models F-21TOLH, F-21TOLBH: 101-105 Dec. 1953 Chassis 404: Models F-21COLH, F-21COLBH, F-21CDLH, F-21CDLBH; Chassis 402-1: Mod- 106-110 Jan. 1954 MUNTZ els F-17TOLU, F-17TOLBU; Chassis 408-1: Chassis 17B1 or 17B2: Models 2053A, 2054-A. Models F-21TOLU, F-21TOLBU; Chassis 404-1: 111-115 Feb. 1954 2055-A. 2056-A. Chassis 17B2: Model 2055-B. Models F-21COLU, F-21COLBU, F-21CDLU, Note: Months priorto September, 1953, refer to Chassis 17B3 or 17B4: Models 2457-A, 2461-A. F-21CDLBU 82 of Chassis 17B5 or 17B6: Models 2158-A. 2159-A, Chassis 411: Models F-24COLH, F-24COLBH; issues ofTelevisionRetailing(predecessor 2162-A 39 Chassis 411-1: Models F-24COLU, TECHNICIAN) F-24COLBU 96 (Continued on page 70)

TECHNICIAN February, 1954 69 Circuit Digest No. Circuit Digest No. ChassisKCS81: Models21-D-305, 21-D-317, Chassis1-509-1,1-509-2:Models187B,BU, 21-D-326, 21-D-327, 21-D-328, 21-D-329, 21-D- M, MU Circuit Digest Index 330; Chassis KCS81B: Models 21 -D -306U, 21 -D- 41 317U, 21 -D -326U, 21 -D -327U, 21 -D -328U, 21 -D- UHF Converter Models C31M, C32M, C332187 329U. 21 -D -330U 67 Chassis1-518-1,-2,-3:Models175-18,372, Chassis KCS83C: Models 21-S-354,21-S-362: 373, 376, 376, 377 97 (Continued from page 69) Chassis KCS83D: Models 21 -S -354U, 21 -S -362U 90 Chassis KCS77D, KCS77H: Models 27 -D -382U TRAV-LER Circuit Digest No. 27 -D -383U, 27 -D -384U 103 Chassis 36A2: Models 217-32, 217-33, 220-36, OLYMPIC 221-36 27 Chassis TK:Models17T40, 17T48,17C44, REGENCY 17K41,17142,17100.ChassisTL: Models 20146,20T47,20C45,20062,20063,20D49, UHF Converter Model RC -600 20K43, 20K51 73 TRUETONE 30 Model 2D1344A Chassis TMTN: Models 17T56, 17C57, 171(55, 61 21T68,21T69, 21170,211'74, 21065,21068, SENTINEL Chassis 21T2A: Model 2D1326A 98 21C72,21C73,21D60, 21D64,21161,211{62, 211{63 68 Chassis 118: Models 454, 1U-464, 465, 112-455, 466, 112-466, 457, 112-457 18 MONTGOMERY WARD Models 1U-532, 1U-552, 1U-554 PACKARD-BELL 85 Manual 4107A: Model 25WG-3066A Chassis 2720: Models 2721, 2722. Chassis 2710: Models: 1U-581, 111-582, 1U-584, 1U-585108 36 Models 2723, 2724 Auto Radio, Model 3511R -6796A 93 60 SHERATON PHILCO Chassis 250XL: Models T1750, T2150, T1756, WEBSTER-CHICAGO T2120, T2156, C2126 RF Chassis 91, Deflection chassis J-1 used in 81 Webcor Model 210 Tape Recorder 1953 Code 126: Models 2269, 2270, 2271, 2273, 62 1853, 1853L, 2127, 2266, 2268, 2286, 2286, 2287 SPA RTON 5 RF Chassis WESTINGHOUSE 81, Deflection Chassis H-1: Chassis 25D213: Models 5342, 5343, 5382, 5383, Models 1824,1826,1826,1852,1862L, 2126. 5384, 6386, 5390, 5391 ChassisV-2207-1:Model H -706T16.Chassis 2125L,2162,2152L, 2226,2227,2262,2272. 24 V-2220-1: Model H -708T20 2272L Chassis 27D213: Models 5342A, 5343A, 6384A, 11 22 Model H-803 all channel UHF Tuner R -F chassis 97, Deflection chassis J-7: Model 5386A, 6382A, 6383A, 10352, 10358 40 56 2760 Chassis 29U213: Models 22312. 22313,23322, Chassis V-2208-1: Model H -716T17 63 47 23323 Chassis Assembly V-2233-4; Models H -746K21, All -Speed Record Changer: Model M-24 29 71 H -747K21 R -F Chassis R-201, Deflection Chassis D-201: Kingston UHF Converter 105 78 Chassis V-2243-1: Models H -770T21, H -771T21, Models 4308, 4110, 4108, 8104, 4008 89 STANDARD COIL H -772K21, H -773K21, H -774K21, H-775121, H -776T21 99 RADIO CRAFTSMEN Tuner Models TV -I632, TV -2232 86 Chassis Assembly V-2250-1: Models 11-815124 AM -FM Tuner C-800 and H -817K24 28 115 STEWART-WARNER RAYTHEON Chassis 9210: Models 9210-C, 21T -9210A, ZENITH 21C -9210C Chassis 17T1: Model M1733A, C1736A, C1736A. 34 Chassis 19102: Models K1812E, K1812R. Chas- Chassis 17T2: Model M -1734A. Chassis 2111: Models: 24C -9370A, 24C-9370AB 109 sis 19K20: Models K1815E, K1815R, K1820E, Model M -2107A, C -2108A, C -2110A, C -2111A. K1820R, K1846E, K1846R, K1850E, K1850R, Chassis 2112: Model C -2109A K1880R. Chassis 16 STROMBERG-CARLSON 19K23: Models K2229R, UHF Tuner K2258R, K2286R,K2288E. Chassis211{20: 54 Chassis 421 series: Models 421 TX, 421 CM. ModelsK2230E, K2230R.K2240R,K2240E, Chassis 21T8: Models UM -2133, UM -2134, UM- 421 CDM K2260R,K2263E, K2266,K2266R, K2267E, 2135, UM -2136, UM -2139, UM -2141, UM -2142, 19 K2268R, K2270H, K2270R, K2287R, K2290R, UM -2I44. UM -2145 94 521 Series:Models 621T,621T0,621CM, K2291E Chassis 21T11: Models M -2131A, C -2137A and 521CDM, 52105M, 521060, 521C5Dee 66 7 C -2138A Chassis 621A series 114 1 1 0 VHF -UHF Turret Tuner 57 Portable Radio Chassis 5L42: Model L507 RCA VICTOR SYLVANIA 79 Chassis 22L20: Models L2671R, L2572R, Chassis KCS72: Models 17T200, 171201, 17T202, Chassis1-508-1,1408-2:Models172K, KU, L2573E,L2574R,L2575E,L2592R, L2693H, L2876E, L2876R, L2878R, L2879E, L2894HU 88 17T211, 17T220 6 M & MU; 175B, BU, L, LU, M & MU: 176B, UHF Selector Chassis KCS70: Model U7042 BU, L, LU, M & MU: 177B, BU, M & MU: 178B, BU, M & MU 12 Chassis KCS78 or KCS78B: Models 17-T-801, BASIC ALIGNMENT DATA 17 -T -301U, 17-T-302, 17 -T -302U, 17-T-810, Chassis 1-504-1, 1-604-2: Models 105B, 105BU, 8 17 -T -310U 105M. 105MU. Chassis 1-510-1, 1-510-2: Models 48 120B,120BU, 120M, 120MU, 126B,126BU, UHF Selector Model U2: Chassis KCS7955 126L, 126LU, 126M, 126MU 35 Copyright 1954 by Caldwell -Clements,Inc.

A New Exclusive Service for TelevisionTechnicians - SCHEMATICS for 25c Each

The publishers of TECHNICIANare receiv-paid. Schematics for all receivers indexed ing so many requests for reprintsor addi-on these pages are in stock. Be sure to tional copies of its Circuit Digests that itorder by Circuit Digest number and give is now making them available for thebrand name and chassis number to prevent trade at 25C each, post paid. For overnighterror. Address Reader Service Department, service, air mail special delivery, 50cpre-TECHNICIAN, 480 Lexington Ave., NYC 17

Economical, official -25( regular mail, 50( for specialhandling by air mail special delivery. Coin or postage mustaccompany order.

70 TECHNICIAN February, 1954 ADVERTISERS INDEX FEBRUARY, 1954 KESTER Since the mast important Admiral Corp. 6 single step in Radio - Television Servicing is American Phenolic Corp. 50 soldering ... it's just plain Astatic Corp 14 good sense to use the best -KESTER SOLDER ... Audel Publishers 65 Key Name in Solder for More Than 50 Years. Brach Manufacturing Corp. 60

CBS-Hytron Div. Columbia Broadcast- ing System, Inc. 16 Caldwell -Clements, Inc. 66 Channel Master Corp. 10, 11 Cornell-Dubilier Electric Corp. 63

Davis Electronics 17

Finney Co. 19 Fretco, Inc. 71

General Industries Co. 64 KESTER SOLDER COMPANY Granco Products Inc. 18 4264 Wrightwood Avenue Chicago 39, Illinois Newark 5, New Jersey Brantford, Canada

Hickok Electrical Instrument Co. . 67

International Rectifier Corp. 65 International Resistance Co. Cover 2

Kester Solder Co. 71 the 'versatile Mallory & Co., Inc., P. R. 13 Merit Coil & Transformer Corp. 2-5 Miller Television Co. 57

Philco Corp. 72 Precision Apparatus Co., Inc. 55

Pyramid Electric Co. 52 INC

Radiart Corp. 8, 9 Radio City Products Co., Inc. 61 family of TV antennas* Radio Corp. of America 15, 63, 65, 67, Cover 4 For proven customer satisfaction Raytheon Manufacturing Co. 7 and higher dealer profits. Rider Publisher, Inc. John F. 67

STRATO-RAY Snyder Manufacturing Co. 68 single yogi South River Metal Products Co., Inc. 61 Sprague Products Co. Cover 3 Sylvania Electric Products Inc. 20 all channel Tech -Master Products Co. 62 FRETARAY Tung -Sol Electric Inc. 58,59

United Catalog Publishers, Inc. 60

Walsco Electronics Corp. 49 MI -TEE RAY there isci FRETCO Westinghouse Electric Corp. 12 antenna for every UHF corner requirement.

While every precaution is taken to insure accuracy, we cannot guarantee against I N C Pittsburgh 13 ,Pennsylvetele. the possibility of an occasional change or omission in the preparation of this index.

TECHNICIAN February, 1954 71 Signal Generator Adapter

P14 ILCO VHf TO UHF SIGNALGEtERATOR AOAPTM moort. 60CIO Individually Calibrated For Extreme Accuracy Now produce UHF signals for TV receiver tests at a fraction of the cost of a UHF generator. Individual calibration guarantees extreme accuracy of UHF frequency. Any VHF signal generator output at 60 MC is converted by the PHILCO Model G -8000-C to UHF. The VHF sweep or marker signal beats against the UHF oscillator, producing UHF signals with the same characteristics as the VHF input signal. It's economical.. .it's aPHILCOexclusive!

UHF OUTPUT Look at These Philco Features VHF INPUT SIGNAL ... 60 MC 1 The VHF signal gener-4 Functions as an external ator output attenuator UHF converter by con- controls the UHF output necting UHF antenna signal level. transmission line to gen- 5" High Gain Oscillo- erator's output terminal 2 Precision Vernier Dial for and connecting lead to scope Model S-8202. accurate re -settings. TV receiver tuned to 60 Givesrugged,general MC Channel 3. purpose performance. 60 3 Each unitis hand5 High UHF levels, excel- CPS phasing of sweep calibrated. lent stability, no drift. generator presentations. Wide sweep range (up to AVAILABLE THROUGH YOUR 100KC) gives extreme PHILCO DISTRIBUTOR flexibility in sweep circuit ON A NEW SPECIALPAYMENT PLAN trouble shooting.

Take advantage of the great .4 CCESSORPHIL CO Y SHARE and PROFIT Program 4.1ARE PHI LCO 7,0? FIr Vgsr g on Philco Receiving Tubes daaa.OUALITY kr/ Parts and Accessories StAtit4Iffi NOW AT YOUR PHILCO DISTRIBUTOR

72 /(92 to -al pages in tnis issue, including Circuit Digests Section) TECHNICIAN February, 1954 WAVEFORM DATADANA INVimMenns siren on February 1954 Waveforms taken with CONTRAST control setfully to the right, 3 0 all other controls set for normal picture tin sync). DX Range Finder -9 as SCHEMATIC NOTES TECHNICIAN control set fully to the leftItit"0" position).Warning:Incorrect C01.1481(L 7014.414 adjustment ofthe DX Range Finder controlwill cause waveform SLUG UNIUSTOISsr Run numbers are rubber stamped at the rear of the chassis. distortion. 0 0 O. On etc. indicate alignment points and alignment connections. CIRCUIT DIGESTS Waveforms atvideo and syncstages obtained withtransmitted Cowen' Nast in 20A2 4 20A2Z; CHANNEL Knob Itemarod. Control Pons! in 2002; CHANNEL Knelt Ransovissi. signal input to receiver. The oscilloscope sweep is adjusted for 30 cycles 1which is one-half ADMIRAL ANTENNAS AND TRANSMISSION LINES of the yertiul frequency), or for 7875 cycles (which is owe -half of is 300 ohms bal. the horizontal frequency) so that two pulses appear on the screen. The input impedance of this receiver M702 M701 The peak.to.peak voltage 'endings shown are subject to some vari- RADIO-PHONO SECTION 20D2 CHASSIS anced 1between antenna terminaLs). When connecting an ations due to response of the oscilloscope and parts tolerances. external antenna for VHF reception only, 300 ohm Jiat transrnissinn line, part number 95A22.1 is mitinfartory. For 64203 FUSE LOCATION 6BE6 68A6 6AV6 6Y6C 10110116115 SPEAKER VHF and UHF reception, use 300 ohm tubular tranynission IF DIP AM DU 111C6 SRO. IMP 50550 OUTPUT OF SOCKET 1011190f 11.116 The horizontal output circuitjarfused with a 1u amp., M703 L704 CONVERTER T 701 1702 CARTIIIRE £111116 V701 0702 /$0 0203 V204 5001 IN MCoi 64202 BLUE -- line, part numbei 95A22-32.lot best VHF and/or UHF 250 volt fuse, part number 84A4-3 which is located on the 64704 f/ yap PfOY /1 Y 212 reception in areas of high humidity or high salt content, top side of the chassis. 11010 /0Y 3 621 MOOR 2 014(ffil77 005 use 270 ohm foam transmission line, part number 95A22-34. ()I- II F.10Y TL.01 31=11 onir 16,:f 3 In VHF installations where the transmissionline paites of 0 o WOK 11-12 I 1215 13150 / =s 2T1 IN 40 S7018 211E6 7202 through reas of heavy electrical interference, the use of 75 J1FD TO PIII 0 8702 1/1 2/ 4212 I THE 1181, 88,11 /00 YAW NOTE: To read schematic for 20A2 PHO ON -OFF R209 W 504 C501 ohm large diameter coaxial transmission line may reduce C104 COI /JO Y 5103 010 0210 43 RH the interference. When using 75 ohm coaxial transmission and 20A2Z chassis, use sections in C213 8221 R2I5 1219 1224 150 PNO RAD T.00 tai C216 1200 heavy solid lines; to read schematic M705 100 (-4 line, connect the outer conductor to the chassis and the inner 1 3' ICI - BOWO 55 15223 1000 11208 .0022 - conductor toeither antenna terminal; usetheterminal for 20D2 chassis, use sections in heavy M706 1216 1220 COLOR DOT T C2,5 DE 59 05 8222 5701C which gives the most satisfactory picture on thc weakest sta- dotted lines and connect appropriate NEC PHO RAD T701-1702 C OM A5 COO/ 3291 1-1" tVOLUNE 8210 .-o--o tion.In weak signal areas, the use of coaxial cable should points indicated by dots coded 55. 71 5701E 0109 201110 BONFO be avoided. 0 RAOn 8106 100 82 5211 -;VOla 1121 etc. Fs Ap For outdoor television installations, we recommend any MFG 10 AC POWER P of the following antennas which may be obtained from your ON 1501 .g or AN3B CIRCUIT RELON DOTTED LINE FOR 2042 I 10421 01/45515 Admiral distributor.Antenna kit AN5 (zig-zag (conical) provides excellent all -channel reception for VHF 20A2 8t 20A2Z CHASSIS channels in most metropolitan or suburban locations.An- T20i _ 64203 tenna kit ANI duo.vee )or AN2 (trombone) provides ex- SPEAKER ASSENEILT

I 6AV6 6AS5 BOTTOM VIEW cellent all -channel reception for VHF and UHF channel, if o4 1202. SOUND IMP SOUND OUTPLII Of SOCIET BUJ so O o6 the stations arein the same general direction.For all - V203 330 2204 5201 5011001 nlM IOTTON sibs no on 6AU6 6AL5 ASO I' /217 channel UHF reception only, within 20 miles, use antenna OF OF C0011111 T301 1302 50340 ,7 AN) WIC DII .01 kit AN65Abow -tie and reflector); for long range recep- 7201 Oa -.3 v201 V202 0 /0 INY tion up to 65 miles, use antenna kit AN56Ai corner reflec TV TUNER 94D46-4 EIMELIO NIKES VOLUME 27- -rr 2 - 10/\x or 5206)1 C214).01 instructions. 2 TEIFFIALS 5 I I 12 6 tor).Each kit contains. detailed installation 4303, 6206 2 1101 OF 500 C209 NEC 52141 8217 /JOY Complete data on ntennas,recommended types for par- 5511 C24 11.1E, SWITCH SETTING SELICIS Ma OF C205 4105' I MEC //Y TO PA 8 TO isgiveninthe 1 002 FN Paint LTE51IE0 0216 ticularareas,radiationpatterns.etc.) COILS 1101 205 4510 41f 8219 OF 514 0501 5209 4113 11201 9 "Admiral Antenna Catalog-. 1105 OA TONE 1100 Nv,e- 2 MEC 8215 80 ME R22 390 .00r21I 390 5% R222 68Z7 C2F07 0210 365 00 2 5 163091 RE AMP 20 4202 4210 .0047= % ADJUST VHF CHANNEL SLUGS 1106 ;.J C201 0,0, 100 214 2100 211 206 8203 IN 6J6 eAsoo- lvtiP C207/ 020111.5 0 C1010 For purposes of simplicity in these instructions, the VHF uaA 005 130 i_102a 0102.1 20 NEP. 60 Wilt ±417MID receiver's Channel Selector will be called Low -Channel Cl05 be L109 COO Selector and the VHF Fine Tuning controlwill called Fine Tuning tab. 70:0"a 105 Le 0106 CmMfal -1, 60 5E1,00. 111111-.' 111111 VERT 6C86 6CB6 I/26U8 6AL5 12BY7 1106 L1301: ST IF 210 If 310 IF DOE 0 OE 1 ACC r,DEO NIP 20 f CnMMIL .4. 44444 v301 V302 V3030 0304 L 332 V305 -I 400.7 A0) _LC113 A4) ,JOr dal floor 003 70 5102 no, 4104 1302 3oF2 Clot 1301 L3-1 06' .4-:-22-'13'2::1 5-: J1117 VHF -UHF Sets. 11111.1' IN OATEN 1500 0 - -711326iT3 :° 2IZP413 OK 3-9 0101 717. 11C T COO , ,y,.I -1 SY IJO JOY 2200 1201221 Channel Seltating Controls. H .3 OY 5, 101 i 7 2 V 10 -5,sr ; 14- YC 8321 2IZP4A 1F 0104 .o 5600 12012 I 20021 100 11100 R304 205 " C313- Individual VHF channel slug adjustment for each VHF S'. 71.°i 8200 " 6F 4108 2 1704Ri197 stationreceived should be checked upon installation or H- 5% R306 -3, 4?, 1 .00' 10335001.C.C43;3511F1311 200 Roll 11,03t4 Clot r I. Rtili: 4333 010211 47 C311 630 4322 servicing.If this adjustment is properly made, itis possi- 11021 Mt 63014 xi 45 22iNibi ble to tune from one VHF station to another by turning the C10 0102 C301 0" 100C 3H-611410 KO AND ANODE 1310 i OS' ''_1:11701711111 -5 Ills~47 CONTRAST VOLTAGE '09 1000 01 Low -Channel Selector only.With correct channel slug 87/10-3- 2110 16.5 IV 0 I?' 9-15;02 ? --'- T 001 - 001 1301 '0"41-. R32 adjustment, best picture and adequate sound will be located 01 R324 r 1000 11312 1100 13515 33 troicE R331-1.-lers1; 1000 0 22 K 1 at the approximate center (half rotation)of the range of 111011 R303 2002 CHASSIS 70 the Fine Tuning tab. 30 1316 T,1 !"!Pr' !r, .C.301 IS0105/12210"sT 1 eon, Zest RFD ILL? 4325 INV 011 IS II 3,17, VHF channel slug adjustment can be made without re- 5302 5305 567 v 1IT) 6.84 '0' POSIT/01 :- "1 _j 454030345, 7 moving the chassis from the cabinet. Adjust as follows: R301 11 1000 W., 110/C R301 a.Turn the set on and allow 15 minutese to warm up. MN' b.Set the Low -Channel Selector for a station; set other 2 /NEC 1140 -I- controls for normal picture and sound. n, CO MO! 011-11 c.Set the Fine Tuning tabat center ofitsrange by 0 102 6441 - ,__ , I /2 I2AUT VERT. 6S4 7- 1510 112 M PILOT LICHT rotating it approximately half -way. TV L105 1401 VERT 05C ri",-1- ,_ VIII OUTPUT / r402 )0106,,,, 04010 C406 d.Remove the Channel knobs and Fine Tuning tab. 306_ 1401 3 1402 ...RIO!- \ 0402 BLUE 0102 H-.- I( e. in the hole ad- OF I.,,4 1 140y Insert a blade, non-metullie tool 1200 1200 RED 221 0047 950,2ti2Lis ku(vJOY 0115 3 100011 jacent to the channel tuning shaft (see front panel illus- 04 5409 Boo 50 V MEC tration).For each VHF channelinoperation, care- "000T12- 004005 00015-- r VERT1111111111110 1403A V301 002 V101 CUES -JOY SY, (Note T R401 5iTt '' 1412 VERTICAL fully adjust the channel slug for best picture. [INEC ti011 1307E T 0410 :7.5.n 560 DEF ITIKE that this may not be the point at which the sound is 'MT -C) 1/--DTC)-4,- Ta IMO 5-6 4135. CHEER 1404 i--§TrI loudest.)Be sure that the Fine Tuning tab is eel at 50 V 5405 TOTAL 4- 2 NEC R 1405 150, NOME 2,5NC 413 the center ofits range before adjusting each channel 5411 560 011011 R410 -10033002^/3:1-3+ 16 V VE111 RED 1.2 NEC .....A 3000 slug.Caution: Only slight rotation of the slug will be To" H0112. MT 115 4- 520 required; turning the slug in too far will cause it to fall 50 V f-o/r--11( 204 vERT VERT V305 REO into the coil.(If the slug falls into the coil, remove the 2012 I 20121 2700 .011 COU LATE R4I5 chassis from the cabinet and remove the coil from the 9_ C4213 CHASSIS 0 63C-12 0306 E 406 IA V IB3 CT tuner drum. Move the slug retaining spring aside, lightly so606 50V n 011111111111111111 VEIT 40112. 35V 150 V RECTIE0R VEIT. tap the open end of the coil until the slug slips out. Re- 110512., L NORIO. 110112. 0406 - place and reset slug retaining spring.) BO V I/2 608 6AL5 6SN7 CT 6BQ6 sr 1441 VERT i/212AV C420 SYNC. INV. 110)112. SYNC. 80111. OSC. HOR12. 01111111 1404 4 In SYNC. SE P. 0412 210 R434 ,F.00 I V3035 0403 /156' 0405 V40)13 PJOy 0404 NNW IfIr171 R419 14423-5Y 5600 5110A5 PICT IS 01 HO/ JO Y slota,- 00) 10% 7c/Y C4I9 CORO SHIELD 2200 11 1006 390 V201 V40 0410 5428 C42I 143,5ri-JOr civic 5% /401,a) 5600 2500V .1 /CIN 4 02 6AX4GT 150, 4424 /8 ( 82 24A5 10112 DAMPER ADMIRAL 1004 5U4G 4121 /I 3 1430 R436 T40373 1.4711 5% 4 2- 0424 040 1 RECTIFIER 4444 11 0410 04 R432 C4211- 110411 avioo. SEE 11441/0111 .0039 I' bod C 1001 44: CRE2E5NA-f 41 1443 DEF. YOKE 81-1011195011- Chassis 20A2, YELL0111;5v40 _ 471 3.9 ME 4420 20ro 38A 2201 .(101 BLUE 000 0501 71427 4431 TOTAL 1110110 MOTOR 142? 0122 :;PO 4 251 4439$ 20A2Z, 20D2 RIO 4411 00 22 T if 2200 8200 1iA442 R111 1,402 150 K Y WHITE rC430 3002 CHASSIS RE J 211 1000 Li, 1 MTH 41112. NOLO 5440 A1,10941 " WHITE CONTROL 1200 1410- 2 SPAR. FIELD M501 11 2111 RED 6 OA CHORE 1501, M401 Technician 771. 18v 4426 Mar C426 RORIZ 2062 1 20420 CHASSIS 3/1 AMPTy SI°hIC 64502 NTERLOCA JUMPER IN ____--,170 ybi'5'.n. -e 410K .011L403 -mom M40i SPEAKERPLUG ' 5433 HOW 041 4:25 -0416 -0:4075 250 11 8501 1201 011141 CIRCUIT DIGEST cc, 0501 21502 87'r 17411 21011 A.7.11C20/01 L,-.1040913) ME III _LEO MID ___I! III - _

An Editorial Service of CALDWELL-CLEMENTS, INC. 480 Lexington Avenue, New York 17, N. Y. PLoza 9-7880 1 1 1 6All6 1/2 6T8 i/L 6T8 6W6G1 50002 DEKUPTION POT NO AT A -F AMP SOUND I -F AM6 RATIO DET ,-1-F OUTPUT c Aoe .1401, 4.7 mt., 500 V. 280209-123 VI01 V1024 V1028 0;03 210 Ceposltrk 209903 002, 003 b0 V. 250175-1 TrO C 211 44por, .22 200 V. 203102-10 C 211 Capacitor, rrrrr 22 ofd. 200 V. 200102-10 C 213 C rrrrrr or, Cereal< Disc, .60s .ed., 210175-1 TECHNICIAN E 214 rrrrrrDoss .u. 600 250201-4 27B V C 315 270027-22 C 216 tops , Gerrie Diee, .031 std. 500 V. 0017S-14 CIRCUIT DIGESTS C 217 Cana, , , .0033 aft, ,400 V. 00101-4 C 301 tepee, .0022 fd. ,400 V. 00211-3 6104206R105 0!O8 600--c4 14_ C 302 .119-9/ 336 Oi C 303 4pacito r, Tare., 1.1 :7::'Y. 3020-13 304 .0047.1e , 403 00211-0 CNO3 \ RI - t 8 t,6 C 303 Cepeeltor, .047 fd., .3 V. 20202-11 R103 ic,34 50161-11041 February 1954 8108 R 09 RHO 8i 7-T4T-2 1 COMO CONNECTIONS NOT C 306 Cepcltor suer 3900 oaf 400 V. 47 1070 12200rat C 307 .1 .1e., 40D V. adl- I.2 SIMEG C 208 MEG S 208" USIVNENPICOHS611500:11111'2VOIND Leperitor, Pepe.,.1 afd 470 50211-I3 .tvOL LIMEG - r--, C 309 Pepe, .047 44., 200 V. 50211-11 000 SENIAL NOS 1E108 113090 L 401 Oar,rrrrrrrrrrr .001 odd., 400 V. 50213-2 .276v C 402 CH4eiter, rata.,.4541 old., 400 v 002111-2 C 43 Capel.r, Pper, Id., 200 V.. 60312-1 2,32 Copeeltor, rrrrr.12347- aid., 400 V. 223112-4 c,,.., R c2 P226 6227 004 2.5 osiF 270 186 BRIGHTNESS Cepecitr, taro, .047 014., 200 V. 220212-4 -N, 404 Capacitor, a., 1000 al., POO V. 200159-133 ,-----,viv 401 W. 240,... 500 V. 250109-5060 108 000 V. 240161-1041 ._c502B : Cepritor, 5ileee Ilc, 1f. 239 Leper ,Peat, .001.84., 400 4. 250211-1 6CB6 T6OF 410 511kor 14124, 470 t 500 V. 2110169-2061 140V 11 1110211-5 CIO VID AMP. SOURCE 'It-- 280v' 412 .... .047 t,40D . 3110211-11 270027-33 68 43 Copocitor, tItetrolyttc, 10/3110 Se. 1.lolud V204 414 ...... 001 22., 400 V. 250211-11 T203 L203 CP.2'0F V206 46 ...... 027 std., 400 V. 250211-11 1 0208 210201-13 6CB6 910 DET VI -VI -VI 4. Capacitor, ...... 1 W4., 100 V. 340,6 1101 Cs...... e, ElsOre ...... 30-40-10/310 V., 110/00 V 270021-22 3P0 VID 801 Cap

2.21 2301.-41 1301 200 "*C'C:ar'r".1,4.4.,01710,00'77 461:7,.14:.IOW Version/ 22010S-01 DOTTED CONNECTIONS NOT USED IN CHASSIS 2200 140V 231 . ,star, 3 227,.0,17,614:,.IV. 1C111.1 22.06-79 WITH EVEN SERIAL NOS. BELOW 122892 AND 040un VHF TUNER 232 Co ro., 37,000 ea., 15. ION 2301.-79 I2AU7 ODD SERIAL NOS BELOW 125193. 10 231 Carat27,000 Ons,II.1061 230100-79 SYNC. 301 Me..., Carl., Am., . 230104-74 SYNC. SEPARATOR SPLITTER 8310 8322 CT CHASSIS TUNER CONNECTIONS 302 12.1 ..... Cerbeo, 470,000424s, W. 1301.-44 3300 470 303 0111 130104-1. 0302 V3010 03015 304 1.1.ter, CaCara..1,000 era, 4 tr. 230104-04 150 140,, _ _,\,\A,...,.63,,', ---140V 2COV z 0303 303 . 230104-81 Car...... ,476,000 ob., 2 V 230104-44 I mF 95 _,_.I0502,1 .6 -3-10mF Carla, 0.2 oe.bo, 220104-104 II 7101010 , R310 6S4 301 Seel Cara., 2700 sae t51, 4 330304-164 2 -1 6SN7GTA MO R305 6 0 0 60 CPS 60 CPS 309 C2elos, 320 or., 11 330104-24 ME,. ,...-!,4 e 3300 a- B2v PPI \V c,i),I;UT R302 478 took V CSC 2701 P P 310 Cara., 3324re, 11, 4 230094-171 60 CPS 6291!0: 311 Cara, 4.7 4 230104-1. 470 6 H.2,I. 1II 2009 2908. V3( 312 Coe., 1000 Oa, 230104-. 9 95 tR501 R303 i4OV 4,00 313 2..... :110..,0C04..e.a,ei. I 230108-09 5 314 20104-9111 Al 6304 6307 PC 301 9,5 V P8t RC390:06,c .703 IP 313 1 110126-19 MEC 1506 B.2 O304 )11 1 etr, j1S501.4 .o.C56 316 Ile el sr r, Carta., 0411as 2 V. 2301.-71 MEG I 226 311 AINt ..... c1,, 6110,000 3010,96 fr 40441 2°° 3 R314 61146 v2 s5MzEEG 3111 Peteetle4142, 210136-40 041,1 312 11.11.r, 49142, 1000 elms, 4 W. 2301.-40 . R309 I_ : 307 320 tr 210121,3 I I 5000 5000-6- 1405 1330 i.IMF - 309 321 n o. ....soo. Cor:44, 100,010 oar.,I11""*. IN I' 330100-811 1'11'4 DOTTED CONNECTIONS NOT USED IN CHASSIS 322 13010, A,13 4V WITH EVEN SERIAL NOS. BELOW 122892 AND 01 310106-44 ODD SERIAL NOS. BELOW 125193 402 .0044-107 R3,2 IC305 .3 Corbe ls,100,000 464, a43, 4 W. 230014-101 I500--.047 R313 !MEC 60 CPS .2009 62706 02809 02006 Carla, 470,00D or. , 41. 2101.-94 45 Canoes, 4.7 4 W. 220104-104 I 3 HOLD 8319 1200v0PB 04 2120106-76 COO 5416 .7 Seek Crboo, 1300 Gas, 2011, . 30044-

400 .Seel Corr..611071"71:7,..2 '11;4 W. 13004-179113 0320 409 0.1 Cora, 01,00 oloe4 230101-011 3000 410 .0136-311 411 wo oe:e, IS,2.. W....:,866, 130094-314 26, 1006 Oro;2 *71.'' 110104-1A : 210122-41 414 3111., .:;;:. ".°°° *"*.' 230104-70 45 C.a., 470,030 sloo, 2 220104-44 16 Cerise, 100 oboe, 4 130104-110 4413 47 .31e Carlo, 1000 46-e, 1 3301.-44 10 4IB Cara., 3 Oa, 1 30104-3 W. 1,1412 IB3GT MF 1500 :g ....E::. :::s,oco :? 100/11 H.V.HECT 5U4G 421 2 2306-6330106-76 21 Car.s, 22,003 One 1 230101-78 V404 L.V. RECT. 501 Wire Iroosd axe NL, A wen, 6BQ6G 230100-114 V601 503 13113104-1 H OUTPUT 301 36-1 6SN7GTA R/Y 501 041 Le 1.1111 -VW 10038-1 CPS 1/40.5 6A X 4GT jsp2 47v PLp O.DC ..... ISO .4sa..-Bly 1001.44 Ca0 160404-11 0402 DAMPERV5 001 00476-1 1606 ...... o. al11.64-1 12402 R4C3 4';0004 i..Tee, 1006 COK 270V 41--rr 0:6007 R413040 08e 3.60V 560 9 25ORR _ 4700 7 HNE ) 6419 101010 Is 409 2060409 82 6 3 000 1000 0410 R4I5 0415 j-CE"sS/ Rr1";5 4706 047 MF IMF l'AIEC IOV 470 R4I4 I( 6AL5 iNti 0406 R41C 4700 1402. 256 +so CPS 5 0414 COO 58420 L402 PHASE DET MOLD ,to r.o I.--. WAS 3342 IN .047 11 LIN 1500 4700 OF V401 EARLY MODELS J501 TUBE LOCErl' 2401 602 6 6C66 6786 408 RECTIFIER lOc F 2ND H OSC 3900 650T COIL SIZE R5642I o. D4 611 4_e 6412 M2D 0412 !F401 0 1500 05018 '010 HF 4422 TOME 150MA OUTeuT 1,4E-7 .10 6406 SLOW -SLOW 074 DETECT. 2809. SOUND 11 2.0 610 :BO. 02223 41.6 _ ) STK 0111.7011 PARTS LIST FOR THE 108A SERIES TELEVISION CHASSIS, PHASE 541.171111 MAGNAVOX CT, CU & CHU 401A; CT, CU & CMU 402A; CT, CU & CHU 403A; CT, CU & CHU 404A 401_141 VE 01.1110 OUTPUT OUTPUT Chassis 108A series TiDdels: CT,CU & CMU 314001. DESCRIPTION PART NO. 511001. REECTOPTINI POST NO. 4047 P111 02 401A; CT, CU 7 DETECT. T 101 110. 360858-1 501 .sets, Filter 3110088-1 C 101 Cerale Disc,.006 .24., 000 V. 180176-1 011621 4CZA; CT, CU & Criu T 102 TTTTT 12.40, N4L Ootpot .0025-1 440401 7 201 Coil, tat 1.F. 340861-1 C 102 Cermic Dist, 60 mf., WO V 28.11-7 :It. 7302 0211, 3,4 I.F.11 Trap 340552-I C 103 Capacitor, Cora.. Al.., .005 OR., KW) V. 1110175-1 4307.0 re: Technician 401A; CT, CU & CMfJ404A T 103 Coil, 30 LI. S Dot. 340883-1 C 104 C oo male, DIsc, 470 =I., 500 V. 2/0062-117 5.1.11107 O. ( T 401 1408110-1 C 1. Coulter,.lof,400 V. 140212-3 402 C 0, No aaaaaaaa 111416 340.0-1 C 1. Capacitor, Elect. 000004 .4., 00 V. 00011-10 T 301 300072-1 C 107 Caput.., Pepoe,.01 mid., KO V. 250311-7 C 106 Copatitse, Pep., .01 ltd.,400V. L 101 T:::::47:75 N.C. 340064-1 210111-7 101 0817.E CIRCUIT DIGEST L 201 Coil, lop., let I.F. 160640-1 C 1. Ca 0000000 9220.,.0047 22., 403 V. 28.01-0 asmetit L 202 Coil, 14.149, Or.. 3.443-28 c110 I4., 180 V. VOW -20 L 203 Coll, V.I. 340443-31 C 301 Woo, 82 ,030 V.(Oil 3101161 1040 L 204 Coll, Fes1149, 360443-30 Cporitr, 00000 Klee, 91 5., 500 V.(CT 080119-46 1100 Coil, Pos.., alto- aaaaa Ita 340443-29 C102 o 494.2. 012c, 00 at 0071 V. 110218-4 L501 T aaaaaa tar, Vertical 041.1 320067-1 C103 Comae 002, 400 220 V. 240110-4 1202 Coll, Deflectleo 340587-1 C 204 Calais Disc, 470 osf., 000 V. 200211-6 L 401 Coil, 000000000 Oseilletor 340879-1 C 104 C.o.s ',Console 0.7, .001 ord., 000 V. 280171-14 L 402 C 00000 I, 3401216-1 0306 Cs Carrie, Dl., .01 std., 000 V. 280174-2 112 C 207 Copeclbee, Coral, Disc, 600 000 V. 240118-4 An Editorial Service of CALDWELL-CLEMENTS, INC. 480 Lexington Avenue, New York 17, N. Y. PLaza9-7880 TEST POINT I3A VI 301 1202 1/2 6T9 V114 1 RATIO DET V1136 TECHNICIAN RATIO DET TRANS IC 1/4 618 6V6GT VIII 7201 V 112 AUDIO AMP AUDIO OUTPUT CIRCUIT DIGESTS 6CB6 6AU6 OUTPUT CIRCUITS -1-_'°°041 C2I3 AUDIO 1-F AMP LIMITER 11111E1707AL 0215 1.201 NOTE OF R F TUNER F1&44 .02MF1 .01MF IQ 30}.39h it SCOPE SYNCED AT112 vERT FRECUENCy 0313 1C206 02I0 1 1 VOLUME February 1954 COG 501E 0216 it* SCOPE SYNCED AT 1/2 $40212 FREOLIEECY rtVI I 3.3 110204 CONTROL - I? 12517 .08AF 5 ;- 47 50v 1 CONY V I 581 5101 C214 R213 DISCCNNECT INTEGRATOR OUTPUT TO vh7A 78 1 L___ _J 470/1 SO THAT VERT OSCILLATOR DOES NOT _ - A i TIUS 4 INFLUENCE F.11.3F C203 8220 5000 5000 500K R214 VcTAGE MEASUREMENTS ARE IN RESPECT R202 6212' 4706 TO CHASS6 WITH A to,000n$ VOL T GENERAL INFORMATION 800 68 MEG METER, WITH CONTROLS SET FOR NORMAL C120 186 OPERATION, NO SIGNAL APPLIED 0141 TEST R203 476 39 I Tha Model 21T7 televislOnreceiver is de- POINT 800 A MEASURED WITH WAN. R14'. R221 signed for operation on channels 2 through 13, 1006 ENCiRCLED LETTERS REFER TO TERMINAL TERMINAL 8026 ** ,.RDS OF TEST POINT DIAGRAM. with provision for UHF adaptation. TEST POINT a VARIES WITH CONTRAST CONTROL SETTNG. AGC C208 Thls receiverbears UNDERWRITERS IABORATORIES 318.1 +260V Is000 approval and incorporates a 21 -inch rectangular SOUNDTAKEOFF 4.5MC picture tube. The Model 2117 utilizes 22 tubes IL 140V and 1. rectifiers, and features the following: 340V Tvo r -f amplifiers, four video 1-f stages, automatic noise cancellation, horizontal and verti- TEST VI 10 cal retrace blanking, automatic horizontal fre- 1 TEST POINT VIDEO DETECTOR ASSEMBLY V108A V109 2iEP413 quency control and keyed delayed automatic gain POINT r- L161 3r PICTURE TUBE 41.25 MC 1/26U8 6505 control. V104 V106 V107 C152 (TOP) TRAP 61 2 VIO5 L157 I ST. VIDEO AMPL. r'ITirrn- NO.viDEO AMR 6AU6 6C66 68 ci51_L c1531_ 6506 6AU6 1 WEL151 27,111 CI81 336 to tuners used 3 ROYCE° I -F 4 TH. VIDEO I -F C167 The r -f tuner unit is similar I SOUND 65V ST. VIDEO I -F 2 NDVIDEO I -F 75 22 C169 TAKE. 11-88-Yvv.. C173 1.155 in other recentGeneral Electric television re- 1.55V 155W [NO/ .0w, 4.36 OFF 170V 1 ceivers, the essential difference being the method 5 81-1 oeyA Rill (71L156 L152 L153 TIN 5 1152 1153 20 0171 RI73 of 1-f output coupling (refer to the accompanying 380MC 4725 L167 71515 310 R169 1664 -C168 3300 6 4NIf I MEG schematic diagxems). An adjustable 1-f inter- TRAP MC ILI54 V 0166L168 1.159 4 TRAP iel$150V. DO ference trap is incorporated in the tuner unit R166 155V 5 1.4(.14 ypeo5VA which may be tuned to reject offending signals in 8156 1.'411 20-120 OAK 45-191.Ta 10 the 40 to 50 mc 1-f range. 0 7_1270 MC TEST Q L158 800 14174 LI R157 m- 2700 ic,72 POINT C182 - R152 en 11300 2 200K 6178 47 filroL3V 100 C157 100 R158 Li64 250V. I ISO 6180 R15 IK 120ah RI75 0156 R R163 100 0-22V CONTRA SPECIFICATIONS G.1 330 116 800 TEST 36 1001),-.R176 - CI54 R182 C 70 Ri8 C158_ R162 POINT 1006 5600 6801 IK 22K EIRIGHTNESS_c174 e00 R154 R153 BOO 2W rz C403C 6ocycles `/ +260V OR8200 I5mF 2W R 76 GANGED WITH POWERINFUTFrequency R183 +260V 6C06 SCREEN RATING: Voltage 115 volts TEST RI86 POTENTIOMETER POINT 470 :E100 -,NAAN- Wattage 275 watts +150V 476 IK No. 2 13 OR 226 114.1. R -F FM. Channels thru No. 6164 ** RANGE: Frequencies .... 54-88 mc, 174-216MC withprovision for UM, r"")6 8165 OPERATIONALPictureI -F carrier 45.75 mc 600V -r TEST tOK 2.5V POINT FRRQUENCIF:3:Adjacent channelaudio VII 75V 420V trap 47.25 mo /4 618 11/ t C306 -L- 75V Sound I -F carrier 41.25 mc AGC 02MF -r t/2 6u8 V- R332 E YE V II 7A VI178 v1113 Adjacent channel video DELAY 6378 DIODE 6A114GT trap 38.00 mc ..5V 3301 VII5B .5V 1/2 :28m7 1/2 128117 C372 2.2MEG OR I MEG R308 VII5A 12AT7 VI 16A vERL VERT OSC. VERT. AMP 5,50V Interoarrier take- M off 4.5 mc 3.3 MEG 1/2 MATT TE NOISE 2125117 6310 C3I3 R337 C316 R322 DI MF9372 V1166 6335 R309 SYNC.AM8 POINT INVERTER C303C304 CLIPPER iSOK --I 1/2 12807 Inv P301 3.9 MEG. HORZ. BL. Undistorted . 1.5 watts R334 270 33K 6 II 6 1. AUDIO POWER 6333 R304 r D301 - 2.5watts 100K 476 60V ^L5V R303 01 C307 MF C323 7 R376 OUTPUT: MX -1M= 6336 47K F 5033 6313 R314 6315 VERT. 3 6331 7 120K 2 306 YOKE 33K IDUI8PEAKER: Type Alnico PM C305 - 1809 4706 R311 226 8200 8200 1/2 inches 1006 C302 :3.5e 1C314 Cone Diameter 6 8200 0.15Z IMF Voice Coll Impedance MF -0320 V 50V R307 6330e2OV ii$361 4.iNF *C232 _ M 400 cycles 3.2 ohms C319 C32 V R319 261,2., 1 R 323 .85F R302 45MF .7MEG EG 390 R329 I 6E000 2900 80 Etuilt-in antenna provided Yoh. 6312 2W 22K ANTENNA IMEG INPUT: External antenna terminals R305 C402A 1 47K VERT 26 t R328 Impedance - 300 ohms balanced R320 01)1 30MFI 226 ground 4 MEG HEIGHT

R374 60V ,L25V +240V MEG R325 YOKE CONFLIBLACK) 48V vERT. +260V HOLD 470 2V 11 -11 11* UHF. ** ** ** POWER 36V 300V J402 +260V 35V 60V 180V D 111111111 11111

470 C403A+240VHEAD END W 7351 6.3 VAC 1:1Tg N7, 0$, = 15404 C368 VI22 118+150V VII9A VI 20A V1208 VI21 :470 153-GT 3750 1/2 i2AU7 VI198 C402B 1/2 124U7 6CD6 2COOW RECTIFIER Models: 2177, 211'8, I MAU? 1/2I2AU7 L401 .21eF HORZ. PHASE. DET 2 HORZ.OISCH C366 HORZ OuTPUT 41.1 HORL REACT. C360 MORZ.OSC 362C363 21170, 21T21, 21C225, +270V C3 8355 R403 R373 21C226, 21C227, 21C228, +140V i MEG 470 100 C40IA 70n 5600 1000 R36i 33A -140MF 5, HEAD END 6354 0353 0358 R363 C375 21C229, 21C230, 21C231, 3K1V 220 t_ -lova 2 686 100K 21C232, 21C233 C40113 BOOV180 C361 6" L355 1401 I90MFaa 6352 R359 R364 6 m. 350V R* C354__ - 27K R379 VI23 1006 3300-1 .001 8 1000 MEG R381 6Ax4GT L35I 270K 1000 VI25 I MF )R357 R3583 6360 DAMPER 5U4G 6353 33K 68K 100K 110R.HOLD 220 RECTIFIERT- 011 R362 0369 1403 1206 -0356 C359 33K R37I 22V mF i2K MO YOKE Plug I W 5KV INTERLOCK R356 511 GENERAL ELECTRIC VI 24 BLARED I_ 220K S4° F401 5U4G RECTIFIER +240V4 ---e R365 6366 336 6372 R.F. TUNER FIL. 8800 6800 300 "EE" Chassis C377 WITH 801 C364 .0511F NESS CONT R176 4 170 %OH 4 VI 13 VII6 Vii5 V119 v120 V1124 v121 2 6T8 6V62 12AK7 12517 MAU?9 12407 6111.163 6CD6 Technician BLACK 6ReEnE R406 VI053 V104 V1093 V1238 VII7 VIIOIL vne2 v10e5 v1063 VM73 ROTA RESISTANCE VALUES IN OHMS 2206 6040' 6118 6846 6A UG4 6AU64 CAPACITANCE VALUES IN MMFD 6405 64547 i2Bn,- 21E84Bi2 4 60864 CIRCUIT DIGEST 2W UNLESS OTHERWISE NOTED. C405 L163 CI78 LI65 .OIMF. +260V C177 1.40 800 1 L448 C179 800 I T 800 UHF FIL 1 Schematic Diagram with Waveshapesand Voltages 113

An Editorial Service of CALDWFL1 CLEMENTS, INC. 480 Lexington Avenue, New York 17, N. Y. PLaza 9-7880 CAUTION NOTICE VIDEO I -F ALIGNMENT Toss T, GENERAL ELECTRIC THE REGULAR Br VOLTAGES ARE DANGEROUS AND PRECAUTION SHOULD BE TAKEN WHEN THE CHASSIS IS REMOVED FROM THE For CABINET FOR SERVICE. THE HIGH VOLTAGESUPPLY (16,000 VOLTS) AT THE PICTURE TUBE ANODE WILLGIVE AN UN- IM.RODUCTION:- "EE" Chassis PLEASANT SHOCK BUT DOES NOT SUPPLY ENOUGH CURRENT TO GIVE A FATAL BURN OR SHOCK. HOWEVER, SECONDARY HUMAN REACTIONS TO OTHERWISE HARMLESS SHOCKS HAVE BEEN KNOWN TO CAUSE INJURY. ALWAYS DISCHARGE THE PICTURE TUBE 2. Turn the sweep generator blanking switch "on". A., The following alignment data is divided into two This will square -wave -modulate the carrier at a Technician ANODE TO THE RECEIVER CHASSIS BEFOREHANDLING THE TUBE. SINCE THE HIGH VOLTAGE IS OBTAINEM FROM THE Br the extremely TEST sownN separate procedures. Because of 60 -cycle rate. PONT VOLTAGE CERTAIN PORTIONS OF THE HIGH VOLTAGE GENERATING CIRCUIT ARE DANGEROUS AND EXTREME CAUTION SHOULD BE high adjacent channel trap attenuation, the con- TUNER CIRCUIT DIGEST OBSERVED. ventional method observation of tease of sweep 3. The next step is to calibrate the frequency THE PICTURE TUBE IS HIGHLY EVACUATED AND IF BROKEN, MASS FRAGMENTSWILL BE VIOLENTLY EXPFiben, WHEN Hence all traps shall be traps becomes difficult. of this AM carrier. 11411 90 11S PICTURE TUBE ALWAYS WEAR GOGGLES. pre -tuned by applying an amplitude -modulated signal and adjusted for minimum signal output. a). Turn the marker and set T TEST generator "on" .4 -Poor 113 2051110N V102 the dial to the desired frequency (4.5 mc, 38.0 mc, 5100 500NN INL. no involves 6AK5 The second portion of this procedure 41.25 mc or 47.25 mc). L.0, 2.e RF the shaping of the 1-f response curve in the con- ventionalmanner by the application of a sweep V1017-7-" V b.) Slowly tune the sweep generator through TEST s generator signal. procedure, observe POW 68574 .' During this the desired frequency. As the desired frequency the usual precautionsregardingwarm-up time, is approached, a strong beat signalwill be ob- TEST TEST V102 equipment cable lead dressand generator output served on the oscilloscope.At exact resonance, a PCIEJJ, 5 100 SHOPN 1N cHANNEN POSITION It 0 6AK5 cable termination. zero beat condition will be noticed, on each side 2.e RF TEsT e0INT It - 122 of which will appear a beat pattern. Minor sweep frequency drift may be V101 COO generator back -and -forth SKTOB 510 TRAP ALIGNMENT noted. However, this drift is insignificant and 50) 6484 T401 b. a Ie/RF 1, may be disregarded. ,00 GENERAL: - Gs TEST vOleTIE 120 c.) Turn off the marker output. is required for of,Afigle As noted above, anAM signal NiT trapalignment. J Aso'. In manycases, the technician LI. Apply this AM signal according to the in- 00 will have a suitable AM signal generator available structions in the chart below. 44499 C(23 It should cover the range of37 to 48 megacycles towngata 680 or« at fundamentalfrequency, with available internal 5. The signal observed on the oscilloscope ap- 400 -cycle modulation.When this of signal is SiO0A )4 type pearsas two parallel lines. When the trapsare elZr7Ieoo sou SOO used, the adjusted for minimum Tont Point Minton. Di -POLE No traps should be properly tuned the distance between these lines 400 -cycle signal as observed on the oscilloscope. will be at a minimum. NOTE: It may be necessary 881 Rne to use full output of the sweep generator and near 680 128 Owners of General Electric sweep alignment equip- maximum oscilloscope gain to observe proper trap ment mayobtain the required amplitude -modulated 13101 tuning. 00 carrier frequenciesby a simple manipulation of aT., the equipment controls as noted below. L-. 1 NOTES: - who do not have either of the .....;. Ii116 Those technicians oda° above equipment available are advisedto omit the 48 it 0103 1. Remove V121 plate cap. Temporarily connect C,28 V1034 5.9 VI038 trap alignmentprocedure. With the exception of a 2500 -ohm, 25 -watt resistor from No 260 V to chas- L 44 ;600 OSC CONV the video amplifier4.5 mc trap L160, the traps sis. C1o1 Tr 9135 ',nee? l',1)12AT7 V211241'7 will not become seriouslymis-aligned due to tube 012.3 18x s'02 t 5 c 111 changes. 4.5 mc trap may be Ste The above -mentioned 2. Remove V115 from its socket. o SIIIt'4 CO S 1105 106 sweep -aligned, if desired,inwhich case a 4.5 mc VAD3A 9 VI038 c.300 sweep signal should be used in step 3, below. The i L -II I 3. Turn theVolume control to minimumand the 050 CONV iCISS LINE trap may then be tuned to minimum response at 4.5 control to maximum. Turn the '503 '"" Ibe)12AT7 (1,9)12 AT 7 Picture Contrast L.0 ctoi mc which should be crystal marker calibrated. Brightness control fully counter -clockwise. 1120 OuTPo 1-I 8105 L ISO " 4. Set ChannelSelector to channel 11 position. 81143 BOO H4 IC136 COAX ;FINE c1 n Obtaining AMOutput from G -E Sweep Equipment Set the Fine Tuning control to itsmaximumcounter- clockwise position. BCC 1-F OUTPUT oX The General Electric ST -4A Sweep Generator will ISO gm 131 F let provide ., BOO]1' ZEE TUNING 60 -cycle square -wave amplitude -modulated 5. Connect oscilloscope to test point #5 (Pio - 2208 j, signal. Toobtainthis signal proceed as follows: tuie tube grid).

O° L 1. Turn the sweep generator sweep width control 6. Allow receiver and testequipment to warm up uNING 4 06146 fully counter -clockwise. This will provide a for. 20 minutes. Refer to figure 4 for trimmer lo- steady (zero sweep) carrier. cation. Align as follows: - c.,za sod 03 L 137 1:40 h neat s6 u TERM BOARD (BOTTOM TRAP ALIGNMENT CHART 0122 07 (3, AGC VIEW( SOO Ills 8200 4 3 41' 12 211 25UVELC 140001. STEP AM -GENERATOR AM - GENERATOR ADJUST FOR REMARKS INPUT POINT FREQUENCY MINIMUM OUTPUT 501COMEEARL., snoTS USED A CHOKE= .C/a521003 OF RIIL

AGE o -o t, o I F,250v0.0140004 41.25 mc 1151 1 _J 47.25 mc L153 May require maximum oscilloscope Tube end Trimmer Wootton REVISED "BIC" VERSION TUNER SCHEMATIC vertical gain IIP Tun, Schornotm Deogrorn Test Point #1 (R -F Tuner Unit) May require maximum oscilloscope 2 38.0 mc L152 vertical gain. If insufficient "null" is observed, turn core of RECEIVER ALIGNMENT L154 2 or 3 turns into coil. R NETWRII Connect detector network between 3 Test Point #4 4.5 mc L160 oscilloscope input and receiver PRODUCTION CHANGES MIL:" mane R -F TUNER UNIT OFFLECTiee ta000 (Diode Load) test point #5 as shown in fig- OeliSEvOLT Tie, OaPle1011. ure 3. Remove V107 during this 1) Reduction ofI -F Interference: - Ir. order to Although this tuner unit (Cat. No. RJX-051) is .11113a 10-evOLTS step. assist in the reduction of i-f Interference an quite similar to tuner units used in recent re- I mI STO adjacent channel trapshield can. RHS-112 and a ceivers it is not interchangeable with previous saes I chassis bottom plate RHS-119 vas added to tie chas515.- production tuner units because of changes in its ALIGNMINT.CHART 1-f output coupling method. However, the r -f and oscillator alignment procedure is exactly the same CONNECT SWEEP 2) Video Amplifier: -The video amplifier :be as used un theModel 17710 r -f tuner unit. STEP GENERATOR ADJUST DESIRED REiPONSF REMARKS waschanged from 6AQ5 to n 6CL6 type. Tr.e com- 11.45510EOWD plete video amplifier circuitry nos been modfied MEseToas Fos slightly using the following components: C4 'ABCD. .101KONE lalaleaNT c 25K 4Ano-ma MEM Into Test Point #2 T151 for proper 42.0 mc L166, L16o R195 and R3,5. Tenet. ICM 9910 OT EM 5tOF COMM Make indicated adjustments courari and chassis thru response. to obtainmaximum con - ayr MT FOR 840 gain 3) Brightness Circuit.- This change was made to .001 mf. Center TI53 for proper 45.'5 me 42.0 .0, sistent wit, proper curve. AUDI C. I -F ALIGNMENT 1 sweep frequency response. provide greater consistency of raster size with 33 TEST 0 s,, 'Is's,. Comers of curve peak must Re- approx. 44.0 mc. T152 & 1167 for zero show slight respect to changes in thebrightness level. 90.000 03*52vaT rounding. Peak NOTES: - Sweep width approx. I -F SYSTEM SWEEP ALIGNMENT ceivers incorporating this circuit may be identi- 5E oa Low1ST React "tilt" and maximum gain .4 oo. of curve may extend 10 % fied by the fact that asingle unit brightness 10 mc. without "saddle -back". (max. beyond 45.0 an marker. GENERAL: - 1. Tune in a television This will pro- control potentiometer is used ratherthan a dual signal. FIG.2. T202 ALIGNMENT POINTS Now that the traps have been set at their proper vlae a 4.5 mc signal source foraudio alignment. type of the earlier production chassis. frequencies the 1-f curve may be shaped. Keep the Volume control turned down unless the Into Test Point #1 4. 25.4G speaker is connected. two 100K resistors should be chosen as accurately and chassis thru Cbtain REVISED BRIGHTNESS CONTROL CIRCUIT maximum gain and NOTES: - as possible, for equal resistance. Be sure to .001 mf. Center L154 and 7105 (R -F Tuner) propermarker positions. E. Figure 2shows a simpleresistor network remove these resistors after completing the align- sweep frequency for maximum gain and 42., /,, Peak ofkcurve should extend 1. TurnPictureContrast control to minimum. needed for the alignment of T202 secondary. These ment. Align as follows: - approx. 44.0 mc. proper marker position. 4s% 45 ',Mt 15% beyond 45.0 mc marker, Sveep width approx. with slight rounding. 10 mc. 2. Connect oscilloscope to test point #3 (junc- 42.sec cos tion of R164 and R165). This vas showninerror AURA' I -F ALIGNMENT CHART 45MC-MO% as test point #7in publication5-2177.

2. Apply a negative 6 -volt batterybias voltage STEP CONNECT VTVM OR ADJUST METER Align for zero"tilt" on ch. 12. Check chs. 7-13 REMARKS to test point #9. Connect positive lead of 20,000 CEPS/VOLTMETER and make further compromiseadjustment so thAt each INDICATION battery to chassis. 3 Into H -F Tuner in- C108 (R -F Tuner'- channel will have no more than t205 "tilt" with the put thru balanced Fine Tuning adjusted to provide the proper sound and 1 To test point #6 and L.I-. ' and 7201 (top 4. Calibrate the vertical gain of the oscillo- chassis. and bottom cores) adapter and 300- picture 1-f markers. Adjust for Voltage to be read is scope to provide a 2 -inch deflectionwith applied maximum negative with respect to ohm pad and line. signal, 1 5/4 volts peak -to -peak. 2 V115A, pin 2 and T202 primary, deflection chassis Sweep channels Chassis. (bottom core) 2-13. Sweep width Align for zero "tilt" on channels 3 & 6. Check chs. approx. 10 mc. 1124 & 1127 (R -F Tuner 2-6 and make further compromise adjustment, so that 5. Note that the followingprocedureuses 45.0mc as the 100% reference point. Maintain the sweep Test Point #7 and center T200 secondary, (topAdjust for Repeat steps 1,2 and 3 to each channel will have no more than /20% "tilt" with generator output so that the baseline -to -45.0 mc- 3 of two 100K resistors. core). cero volts proper final adjust - thePineTuning adjusted to provide the proper sound assure marker amplitude equals2 inches. Align as fol- See Figure .. d -c output went. andpicture1-f markers. lows,-

An Editorial Service of CALDWELL-CLEMENTS, INC. 480 Lexington Avenue, New York 17, N.Y. PLaza 9-7880 An Editorial Service of CALDWELL-CLEMENM, INC. 480 Lexington Avenue, New York 17, N. Y. PLaza 9-7880 February 1954 WARNING TECHNICIAN At all times during operation the chassis is at 125 volts DC potential above ground and it also may be of the line voltage potential depending on how the line cord plug is insertedin the power SCHEMATIC DIAGRAM CIRCUIT DIGESTS receptacle.

Extreme caution must be observed when working with the chassis outside the cabinet and when OSC vC-. CAVITY UHF-VHE power is applied to the receiver with Ike cabinet back removed. SEVERE SHOCK mayresult from CryIN82 SWITCH UNE NOTE PLUG NOT USED WHEN ANTENNA CRYSTAL 6AF4 INCORPORATED. confect with chassis, TERMINAL UM' TUNER IS UNP L304 L509 IrAt-a,.6r.Tor OSc IMF IF C3130 132V An isolation transformer between the line plug and power receptacle must be used when service ci1_ JUMPER PLUG .1;1.2. I v-3 147' is required. This removes AC line shock hazards. Damage to the receiver and test equipment may .1111:4 V-4 6CB6 0100 OSC WNW 4700 ?7"Trm L304 LO3 2,0 IF result without the use of an isolation transformer. 10 6C86 lit 1, F PLUG 13°C 4( H0O 5 6 3331 1C,00 = 'Co LIO0 CO POINT C300 ssoo col 0 4,- RV: C0038 L' PLUG 70iW L309 -11100 0302 C1,002 1 4104 = 000 4 L09 1 IGO 8108 023 8301 0308 3900 8200 2000 1310 r1.31571615- ---IRLS;STOR WATTAGES REPRESENTED IN III WATT VI- 4500 8303 I C309 E THENwISE NOCATEO DENOTES 1000 DENDTES Z1000000 UO4 41 K.Aa7 e we ALL MITONS ARE SNOWN IN THE POSITION TOO VNf 11107 1-1 61141 ,500 3303 _r_C107 8304 1000 1312 V-19 LIOR --"*-1.0311 A CA VSTA 8302 1000 I680 az SWOT v -H3 40sER 8300 "CC* L3I4 siweit was CHECK 4 6BK7 1000 1000 S Lu4 40CAI 6643 ;"15"T's7Lira TAM 2;4 4101111 WERETIf IIFTHK:C2'0',"SS OMIT CASCODE Am C308 30 - V -1T 40.4L ORER0r100.510 SIGNAL /OUT MCI LINE VOLTAGE AT HSV RC WHERE ICIO5A uoc 00 CONTROL SETTINGS AFFECT vC4.110E READINGS THE oArNDAR4 APO mmINvN 4102 p 6AV6 ' ALS "Ts' 08 3000 ME INDCATED (SEE WANING I '°°° L303 1307 9 ON PLATE CAPS OF THE 1133 CALICO 221 8314 2245 alEFLYCUM1=14GP. CIOS 7000 3900 ERGS PIECTiElEtt AND 258013 .12012014TAL FuLSE APLIFIER CO 100T MEASuRE THIS u:,;C:1:17ER v' Wl. DCRIE at. Ina ANOOE VOLTME WITH v PROSE 12 UHF POWER 119 GALA I2AU43T rat THE DC RESISTAKE FE0403 ROCOCO .TAR THE m. 4M, Mt. aM MN. MOP MID MO Mt =MP IMP !MIMI 11 MI _L 630 ACE, BRASS COLS NAVE MEE 14 TAKEN WITH AN OHMMETER DAECT, vJUMPER 1000 PLUO V3 TME COL DENG MEASURED COILS SHOWN 4.THOuT A RESISTANCE L R208 C231 000 16506 340e 12AT7 REA0440 HAVE A DC RESISTANCE OF LESS THAN ONE OHM TOLERANCE 235V L303E _10 IS PERNISSIBLE CO NOT MEASURE WITH SET TuRNE0 v-2 V 20 5201 P208 2400 6607A 6AX4 HE WAVE FORMS ILLVSTRATED ARE EXACT COPIES CF T moo 5 ALASORATORT 09CILLOSCOPE THE WAVE FORMS WERE 020°89 2 3 0 TANEN UNDER POPPIAL OPERATNG CONDITONS, WITH TAINSIATTED :ANAL L30 ICU. 02 ANO THE PICTURE IN SYNC AT ALL TIMES WITH LARK.75(2 FORM IS THE T E DETECTOR PEAR'TO-PEAR va.TAGE NO A HOWIZONTAL OR VERTICAL MCITAT1C. V-3 OUTPUT v-7 REPRESENTING vERTiCAL 160 CYCLES) DR 140PiZONTAL 115,750 CTCLES) 12AT7 :LT UAL, 15515 SCOPE FRED TNT WAVE FORM APO PEAK TO PEAR vOLTAGE READINGS L)ITIVERTOSC PERM ,6 V-5 MOM11LuS IAN VARY SONEwmAT DEPENOPO CP. THE STRENGTH OF TIE SIGNAL. TME 11064 NCTLNE INFORMATIoN BEING TRANSmiTTED AND TIE ADJUSTMENT THE %COG 10221 vARIOUS CONTRC4.3 AMEN CHECKANG WAVE roews.ccreact 05050 T0000 LEM:IFNI. TIE OSCILLDSCOPE TO T.5 C.553 MO THE HOT LEAD TO 'HE 2200 10221 C222 POSITION INDICATED 67 THE ARK/. 22 44 10 4.2 TV. 5203 C223414 T201 5204 RIOT SI T 118 225 C20 0405 A201 ov4, 8204 1000 4,2200 L208 0215 `deb RF L209 } 4202 000 r TEST o-$0 TC2.18.1.C2i7 8208 POINT 220K 322 7C2 .1. 4711 C210 l206 = = yrMOO 41150

000 .000 T C228 1000

VPI FATE.. TERMINALS Nv.w. REPLACEMENT PARTS LIST 8419 54 Ref No Part No. Description RefNo. Part No Description C424 04714 25C5 1.10:50 VAL T403 404 TROT) TOI V -T50 Y 20MCVHF TUNER 34 8439 Ifs 8443 .054 loom I2AUT 654 Capacitors Chokes, Transformers, Coils v e C OUTPU1 1805 0200 8641892 22 mmf. ceramic T200 3E 22082 H B +len, 1,11510,,e 350 -MOON C101 A.8 80.17142 5.20 mmf, dual trirranet T201 13E 21671 L BAntenna Nonslorann, 6AV6 500A 1100 11M 20781 Cescode CAMEO2.14 P.I2A; C101 86.16045 110 mmf, ceramic 250A C203 86-108P0 6 rrant. ceramic feed 1201 11M 20780 Calcode coil 07F 00 750 C104 5000 nun). ceramic L232 17E 11046 L RF primary coil Im 86-11612 R44. 0705 8G-12495.8 1.5 mmf, ceramic 3263 115 17140 H BRF chest., coil 225 10-354 SOW PLUG C206 86.21747 1000 mmf. ceramic L204 13E.11046 L 8RI secondary coil 470N C207 201.12333 Ttimmer condenser 1205 131 17140 H.B.RF secondary coil =OP"' C108 86.13101 1000 own), ceramic L206 164 .10777 Filament coil 11442.11-52V... C109 86.12495.7 1.0 wnf, ceramic 1707 I 6A.17128 OF choke coil 1V.1.121LIM 8 86.13201 1000 men!ceremic 208 130.12155 L B Oscillator coil C210 300D 4r 1.209 13E 17140 H B 074.11.10r Voll C414, C2Il 86.13017 15 mmf. ceramic HOW C212 101.16141 Trimmer condenser Miscell 30CMI 1.0 mmf, ceramic C713 86,12495.1 S200-201 71 16310 SI.d eg 1ch contact Trimmer condenser C2I4 2014/333 202 201 R44 0215 86.13101 1000 mmf, crarnic Y'19 201-22081 Antenna trenslchmer assembly ILLS C216 8649314 4 rnml, ceramic (Includes C200 C201A BC704 0217 101./2333 Trimmer condenser 8200, 7200 and T101) 1000 mmf, feed *Fru IS5 C118 86.10878 700,20772 Antenna shieldassemble RP 0219.720 86.13201 1000 non). ceramic 201.20766 Cod ahgnment strip CSOe C21I 86.12495.2 10 mmf, ceramic 51.16311 Spook contact kolder 0M -0,F SWITCH moo, r56!Sa 2.5 own). ceramic OM VOLUME tea 0121 86.19568 200.20779 Sw;tch lever aernElo PLUG Mt CONTROL C113 86.11891 51mrni, ceramic 10 20893 S.,ch leverbrsiacket _MY C224 101.22333 Trimmer condenser 200 18824 Rem c C215-176 86.20878 1000 mmf, ceramic feed 100.21803 Shaft andfront cam 7 mmf. ceramic C227 86.15224 200 20881 Bottom cover 0728 101.21333 Trimmer condenser 201 10769 Capacitor plate aemble 1:0 x204 C129 86-13201 1000 'Peel. ceramic (Includes C218,126.ts216 730./311 10 Aso C230 86.20879 6 rranfceramic feed Ow,. 49A 20763 Hair p,n wing 1.77W:4 C231 86.20878 1000 rramfceramic feed TO,, SM. 18807 Treadle bar czoa 2M.16276 Core munting clips Resistors 43A2.5444 Hey-nui.o 2.56.3 16 T. _C3C6 R4411 44-4714F R200 9131.94 470K ohm, V, watt, 10., 51A15713 Iron core(white)for L209 --n R101 981.62 1000 ohm, 1/2watt, 109', 51A 17162 Iron cor (brown(For 1203-105 THESIS TOR 040142011TAL 13102 981.74 10K ohm, V, watt, 109,-, 51 A21200 Ironcore(pink)for L108 TYPE FUSE 450.400 C6a VOLE NAIG 13203 981-38 10 ohm, V, watt, 101'a 51A15715 Iron CO,( blue)for 1202 5410 10447 R204 981.78 22K ohm, v, waft, 10" 51A-17161 Iron core (orange) for L204 150 981.27 2/0K ohm, V, watt, 201,. Front end plate 1 R205 2C-18004.1 IS MCS R206 981.66 2200 ohm. V, wait, 10'. 2C.18805.1 Rear end Pkt 5 " R207 981-74 10K ohm, 1/2waft. 101- 49A.18799 Link spring 5208 981.13 1000 ohm, 1/2watt, 20 2M.18P00 Frontlink 1209 981.50 100 ohrn,v, wait. 10c. 21,4-71278 Rear link 7M-19150.1 Flat spring 78-19313 Tube shield Rel No. Part No, Description Rel. No. Pe.1 No. DeSCNption 711.13050 Antenna terminal board L3L11 16A-21656 RI choke coil 198.19922 UHF IF socket end IF alignment 20MC I FAMPLIFIER L301.303 16A17937 Filament c6ohs cod input socket Resistors L304 201,22917 IF coil assembly 201.21651 UHF IFjumper plug Models: M -2131A, Capacitors L305 16A-17937 Filament choke coil 198.11910 UHF Tuner power socket RAYTHEON 8300 982-79 27K ohm, 1 watt, 100, C -2137A & C-21381 C300 86.19502 10 mmf, ceramic 1104 16A18676 RI choke coil 19A21744 UHF POW., iumper plug 8301 981.73 8200 ohm, watt, 10% Cl01 86.13962 5000 mmf, ceramic disk L307 16A-17937 Filament choko coil 7n-27811 AC mounting board brecket R302 961-62 1000 ohm, V, watt, 10% C302 8E3-8 100 mmf, mica 1308 164,18626 RF choke coil 20,12809 Tuning shalt bracket Chassis 21 T 11 R303 9131.46 47 ohm, w 0+ ID% C303 86.13101 1000 mmf, ceramic L309 101.11919 IF coil assembly 3A22812 Tuning shaft R304305 981-62 1000 ohm,V, watt 10% C304.305 Included with 1304 1310 101.15608 RF choke coil 200.27930 Follower plate and spring R306 981.80 33K ohm. V, watt, 10% C306 8G-19521 1000 mmf, ceramic L311 16A.17937 Filament thole coil 3M.12389 Drivholt pin (3 used) R307 981-46 47 ohm, 1/2 watt 10% C307 86.13201 1000 mmf, ceramic L311 313 16A.11923 Peaking coil 290.72395 Ring retainer(2 used) R308.309 10 981-62 1000 ohm, ..t. 10% 0708 80-13962 5000sssissrsnnsdi" 1314 164.19365 Peaking coil 700.22933 Drive pulley and bushing Technician R3I1 Included with 1309 C309-310 861 3201 1000 mmf, ceramic L315 101-20165 Peaking coil 200.21934 Drive cord and spring assembly R3I2 9131-49 82 ohm, V, Het. 70% C311 86.71105 680 mmf, mramic 098.1 23108 Circular retaining ring R313 9E11.62 woo ohm, w ot. 70% Miscellaneous C312.313 Included with L3D9 000-12722 Shield of lor 1304.309 9131.69 CIRCUIT DIGEST 0314 86.13962 5000 mmf. ceramic disk R314 3900 ohm, V, watt, 10Elr. 20.22153 Chassis bolt bracket 38,1 23018 Cardboard insulatorfor above C315 8G-13201 1000 most, ceramic 43I 5 941-80 13K ohm. 39A-12252 Bracketinsulator 430 19967 Coilfastener for 1300.304 309 C316 86-13962 5000 mmf, ceramic dish Chokes, Transformers, Coils 15C16007 7 -pin, tube socket 28.22915 SALS bottom socket shield C317 8G-1 3101 1000 mmf, ceramic 2M-17589 Shield base 2C-71921 IF socket shield plate 1300 13812939 IFlren%Forreer C318.319 86-12166 5 mmf, ceramic Output 15010440 RF Dower socket 201-22940 F Output lead assembly C320 86-12495-5 3.3 mmf. ceramic L300 201-22924 Converter coil 1H.17588 tube shield An Editorial Service of CALDWELL-CLEMENTS, INC. 480 Lexington Avenue, New York 17, N. Y. PLaza 9-7880 114 Rf, No. Part No_ Description VIDEO IF ALIGNMENT TUNED ALIGNMENT 1.Preset trimmer screws C-212.217-207-214-228.224 fo dimensions shown, elgure 3. Signal7 Sweep Signal I RAYTHEON 21" DEFLECTION CHASSIS Icont'eli 2. Preset coil cores L-203-202-205-204.209.208 in the following manner. Step Generator Generator Input Output Remarks Adjust Response Chassis 2 171 1 1400 16A 20021 Pealr1ng coil 1130UH1 No. Freq. (mc.) {mg (mc.) Point Point (a)In low band position, turn tuner to top of stroke (cores furthest out of coil). 1401.402 164-19486 P.1179 so, I380UH) 6403 (Ina 201 22581 V'cloc, Trap Coil assns. (b) Switch will be in low band position. TexhAlcran IF ! C406-407 8 23.9 IF alignment rS.°Po of Connect short T300 pri.(top) (c) Adjust coil cores 1.6 inch from cora to cad of coil form (use core aligning fool if available). 25 defector ' between pin 1300 sec, (bot.) CIRCUIT DIGEST R420 1 26.3 input i If -video 1404 16A 71114 Frlter choke 126 HI output 5 and 0 of tube 5 Coupling rod_ . LOW BAND RF TR.9414,ING Turn Tuner to Channel 6. L405 (Intl. 201 71301 H Hold cod wan. __ _ _ _ S -sound NOTE-Low Eland must be aligned before High Band. C440 Marke s should fall 10% down. If response curve is not as shown., readjust coupling rod (bottom T300) Slinel Sweep Signal 2 Output Misc.!, for proper bandwidth and 1300 primary and secondary for flat response and maximum gain. SNP Generator Input Remarks Adjust Imponse 114 Mc Generator Paint 21112263 Chassi, boll bracket freq. (etc.) Freq. (etc) Paint 394,22252 Bracket insulator Remove short. 41 M.22446 Fromt control insulator VTVM at IF __, Converter Adjustgenerator L3096 Maximum Antenna R. F. Adjust for maximum 15C.16007 7 -pin tube socket 21.2 detector 1 1 grid for output of approx. reading Channel 6 C-2018 cconven 2M-17589 7 -pin tube shield base output (bottom core) 1V-83.25S-87.75 Terminals Test Point response J , IIEPLACEMF:NT PAIITS LIST MT 7588 Tube shield 2 volts DC. 158.01968 654 tube socket 15C21595 9 pin socket and sprieg a x00 VTVM at IF Adjust generator V-43.25 Antenna R. F. Adjust for maximum C.207 Ref. No. Part No. Description Converter Maximum 2 Channel 6 200-12737 9 -pin socket and adapter plate 26.5 detector for output of approx. 1309A 5-87.75 Terminals Test Point response C-214 PA 194.22525 Speaker socket grid output 2 volts DC. (top core) reading Vertical yoke socket 21" DEFLECTION CHASSIS 198-22671 V-77.25 Adjust tuner until re - 1513-21186 Lytic moun11ng plate for 0429 VTVM at IF Capacitors Adjust generator S -81.75 Channel 5 sponse curve appears 1913.12541 H. Vpower socket 21.2 Converter detector for output of approx. L3098 Maximum C400 81 16082 .22 old, 200 vol. molded 144-22266 R446 terminal board grid (bottom core) reading V-67.25 on scope. 0401 81 16085 1 wild. 200 volt, molded Video input terminal board output 2 volts DC. Channel 4 14421267 5-71.75 Antenna R. F. Adjust trimmers for C-207 C4024B C 80-22523 10 mfd 300 volt60 mfd 50 volt 20.22564 Pilotlight mounting bracket 100 old 300 volt, 10.6 VTVM at IF Adjust generator V-61.25 Terminals Test Point compromise which 37422512 Pilot light shield Converter Maximum Channel 3 C-214 0403 86.13961 5000 nwri4ceramic d.s1 47422513 1. H. Pilot Irght socket bracket 6 24.0 detector for output of approx. L304 S-65.75 will give the best C404 81 16083 .1 refit 400 volt, molded 474-21592 R. H. Pilot light socket brach. grid output 2 volts DC. reading V-55.25 Channel 2 overall response C405 81 19751 022 add. 400 volt, molded Mounting clip for C430 JA 10.11002 S-59.75 across band. C406 PG -17166 S rwei, ceramrc 2D-12063 Mounting clip for C400.421.437 VTVM at IF Adjust generator C407 8612198 47 rrowlceram1c Converter Maximum 211.20097 Selenium rectrfrer 25.0 detector L300 C401 86 13967 5000 mrefceram,c 7 grid for output of approx. HIGH BAND RF TRACKING Turn Tuner to Channel 13. 437,15390 Control mounting nut(8 used) output 2 volts DC. reading C409 Included re* 7400 514.11740 Iron core for 6405 C410 8120634 .0022 mfd, 400 volt molded 430.11666.1 Speed clip for 6405 Scope at IF V-211.25 Antenna R. F. Adjust for maximum C411 873.124 820 mmf. 300 voltIn.cn 20122551 AC Line cable asset. Converter Rock for flat C4I2 Included w1th 7400 25 detector 1300 pri.(top) 1S-215.75 Channel 13 Terminals Test Point response 0301-A(---\ (Includes 3 items Below) 8 grid response C413 PG 13961 5000 rnmfceramrc 4IM-72434 Idount.ng plate output C4144 B C BC 21524 10 old. 15 volt10 mfd 15 volt 194 19446 AC receptacle V-211.25 Antenna R. F. Adjust for maximum C-212 20 mfd. 300 volt. 111.0 8.rnr6 sleev1ng Markers should be Channel 13 554.19819 2 S-215.75 Terminals Test Point response C-217 C4I5 81 20582 .01 old 200 volt. rnolded 15131127E69 CRT socket and cable 23.8 Scope at IF 50 down and re - Check J--' C416 8622132 5000 mrnfcerarnrc Converter 201,22441 RF power plug and cable 9 25 defector sponse curve should point V-205.25 C417 81 20382 01 mid. 200 volt, molded 514-22370 Iron core for 6403 26.65 grid C4111 8J-16084 01 mfd. 400 vol. molded 430.19967 Coil tube Testae,- for 1403 output be as shown.If not, only S-209.75 Channel 12 C419 86-21708 .01 ofd, cerarelc 46A 10193 PilotI,ght bulb repeat alignment V-199.25 Adjust tuner until re - C410 81 16081 047 old, 400 voltmolded 148.20183 Welded w1re S. -203.75 Channel 11 sponse curve appears C421 TIJ 16095 22 mfd. 400 vol. molded Picture IF frequency 26.75 MC - Sound IF frequency 22.25MC. C472 174 22376 Printed circuit V-193.25 611 scope. C423 8120580 0047 wild100 voltmolded 21" H.V. SUPPLY NOTE: A very short lead from the generator must be used to prevent regeneration. S-197.75 Channel 10 Antenna R. F. trimmers for C.212 047 old. 400 volt. molded C424 8J-16081 $ V -18 7.25 compromise which 8116096 047 old. 200 voltmolded Capacitors Terminals Test Point C.217 C425 S--191.75 Channel 9 will give the best C426 81 16083 1 molded old 400 volt C500 86 19863 47 wes0cerww,c \\ 81 16097 molded overall response s..' C427 mid 600 volt C501 873.121 470 remfSOO vonrercn VIDEO THAI' 1.1111. 1.-1031 V-181.25 100 old 111, .111611"ST'AIENT Channel 8 0428 13C 22285 150 volt C502 8170589 0015 cold. 400 ...Ifmolded S-185.75 across band. 100 wild C429 BC 22786 150 voltIv, C503 8C-22544 50 old 450 volt, lyric 1.Tune in a station. 4.Turn the slug in (clockwise) until 8121505 41 mfd 400 voltmolded V-175.25 Channel 7 0410 C504 8116081 041 wild400 volt, molded 22 mml 2. Adjust the tuner until sound bars just appear. the horizontal scanning lines are 5-179.75 C431 86 11892 C505 8121505 47 old 400 voltmolded C432 873 123 680 reref300 .011 cn C506 136 21440 470 meg 1000 volt, crramw 3. Turn L-403 slug all the way out (counter-clockwise).smooth and continuous. C433 853 117 720 Tr^i500 vol.rwcw LOW BAND ORRI'ILLATOR TRACKING Turn Tuner to Channel 6 C507 81 16082 22 old 200 vol.molded C434 873 1I7 87 moot500 voltrwre C435 873 123 680 reml 300V01. P700,1 Resistors Antenn. Scope at Adjust until marker is C436 873 III 220 mref500 volt m.c. SAII"!III IF.%LIGNAIENT 1 83.25 Channel 6 IF Detector 50% down on low C-224 iww... C437 81 16082 22 old200 voltmelded R500 981-88 Terminals C438 8120578 0077"veld100 voltmolded #501 981 .50 10C 3- Short antenna to ground Output frequency slope C439 873-119 310 mmf wcn 8802 981 94 470Kr. e- 8503 100 oh..' 0440 81 20613 0039 mfd600 voltwelded 984-74 VTVM Maximum 67.25 Channel 4 Scope al Marker shouldbe R504 98265 1800 oke- IF Detector 1400 Primary Antenna C441 Included -016 7405 4.5 across Reading on 2 IF Defector 50°o down on low C441 114 22376 Printed crrcuo R505 984.70 4700 ohm Output (Botom of can) 55.25 Channel 2 Terminals R506 9C1.1070 3 9 ohm C.416 V.T.V.M. Output frequency slope Resistors I watt R400 981.98 rnegohre, 10 Chokes, Transformers. C0116 IF Detector Scope Sweep approx. 100T400 Secondary HIGH HAND OSCILLATOR TRACKING Turn Tuner to Ghana': 13. R401 10B 17318 Sync Stabilaer control3 meg 0500 H 701.72196 s 2 4.5 41Cr0SI KC. Adjust tot R402 961-92 3301 ohm,1/2 watt10 (Top of can) r Output 20-22253 C-416 maximum linearity Antenna Scope at Adjust until marker is R403 981.82 211.15 Channel 13 IF Detector 50% down on low C-228 R404 9BI 100 Miscellaneous Terminals Output I frequency slope R405 9B1-82 47K ohm , 394.22151 Bracket . Scope Sweep approx. 100 158.22335 Vole sort/ IF Defector T400 Primary R406 981.76 1541 ohm 0 156.10440 4.5 RCM. KC. Adjust for Scope at R407 984.82 47K ohm 7 - , 25806 lobe sccio 3 Output 193.25 Channel 10 Marker should be 158.20860 6A04 tube socket C-416 maximum linearity (Bofom of con) Antenna IF Detector R4OB 9(31-77 18K ohm - 10 2 175.25 Channel 7 54% down on low Terminals R409 10B-21311 Acture CC,' 530 06w 14412540 Dual H Vpower plug Output frequency slope R410 981.76 15K ohm s 3, r 10 201.20811.1 183 Socket vssemblv R411 981-88 150K ohm 3 or 10 I4C.12282 I H VCoble assembly R412.413 984.68 3300 ohm2 3.° 10'' 1821263 Shield can 1'111': -ALIGNMENT R4I4 901 70 4700 ohm o) 10 28.12264 Sh1eId can cover R415 108-21456 8r,91,1ness - 5001 ohm 30A.19991 Insulator Ow TURN BOTH TUNER PULLEY AND TUNING SHAFT 494-11633 Ring L3 1.If sweep generator does not have a balanced output, R4I6 981.90 2201 ohm - or10 (1 used) TOP * BOT TOM00 25 OW R417 981.62 1000 ohm 00 10 20-11490 Mounang clipfor C503 connect a 150 ohm resistor in series with the ground COUNTER CLOCK -WISE AND RESTRING AS SHOWN 2041053 Mountrng clip for C507 8418 9131-65 1800 010- -010 lead and 150 ohms minus the infernal resistance of BELOW 8419 981.68 3307 3 , 30 20 11002 Mo0w1ng cl.p ler C505 8470 381 86 L304 the generator in series with the hot lead. R411 981 51 TTOM 24 OMG TENSION 7 1/2 TURNS 8422 984 71 8200.ow-2 wet.100,. 21" C.R.T. MOUNTING ASSEMBLY SPRING 2. 8423 981 46 41 ohm ' watt, 1041, Connect a 1000 mmf capacitor across scope terminals R414 981.18 22K ohm1/1 we., 10",, 1405 201-21697 Dellectioe yoke assembly -- TUNING SHAFT 244,27664 Tube 11rap and a 10K ohm resistor in series with hot lead as close 8425 10A 27305 0' 04 Volume control 1 meg L309A to test point as possible. R426 981 78 77K ohm, 1/,watt. 10' 2D-21666 Tube Orap bracket 20.12660 R427 981110 10 megehre 14, watt 10 Tube mounting bracket 23M-02106 Carriage boll12 used) ) wellfer R428 981 90 71041 ohm 2 10 PIN 3. Connectsignalgeneratorthrough a 1000 mmf elk R419 9BI 94 4101 ohm 14, watt,10 43414.22707 Carriage bolt nut R430 9112 51 120 ohm I.,alt. 107, 10-12658 Tube supoot bracket capacitor. 10-21662 Yoe mounting bracket L309B R431 9C1 1070 3 9 ohm, 1.,watt 10 TTOM 1 MC Retainer ring 8412 961 102 2 2 megolwn watt10 25M-11653 TUNER PULLEY CLIP I TURN 8411 434 981 B2 47K ohm. ", watt 10 31e1 22659 Tie rod 4.When aligning the IF Amplifier be sure tuner is set 16M-22602 Lrnearoy magnet 8435 9BI 86 100K ohm 07)watt 10 approximately to channel 11. R436 9BI 108 680090300. watt 10 166.4,22601 164 20697 T300 e 8437 10E117318 Vertical Hold 0000,013 wog Center,ng 'eager. r TTOM 2399283 8438 9BI 102 7 2 mego6re we.10'' 1644.19906 Ion trap megnet .. I. 0141 3.71.14. 41E15569 loneardy A An cosh,on w ng col 8439 981 86 100K ohm ' ..11110' *MARKER FREOUENCIES R440 108 22)07 V...104136e control1501 ohm 3218.20807 Yoke wng nut

R441 ' 201,22489 H Vole cable and plug 981 101 12 wegohre watt10 000..I. T.. Cwxth vu.. CORE RETAINING THE DIMENSION SHOWN ARE R442 10E1 27104 V. ,r rvI 6,164 contr.?6000 201 22690 Vole cable and plug TREADLE BAR NUTS APPROX FROM nit SHOULDER CONNECTION TO I-209 L204 1-202 8443 r 86K36.4, OF SCREW HEADroMOLAITING 987 39 I wet 10 CONVERTER R444445 981 07 1e,00 06w we's 10 21 SUBURBAN CABINET PARTS Mb) BASE L209 205 L 203 R446 16M 22301 Res rsr,type lup REAR CAM 740.22818 CaloWet 1M 11111 12AT7 6132 7 R447 964 27831 150 03,,IS 10 - -1- 240-22897 Calo1ne110 21371 Ref. No. Part No, Description R448 SON 27775 2100 ..he10 watt10' 140-21893 Cabo,. IC 7138) N 1500060010 coo 10 C224 /i 30M-11485 Safety glass 8449 9BI 88 1501 03,01.11, 0a11. 10 254420871 Rubber cuth'on 13 used) LOW BAND OSC /6 #450 451 981 102 U1 weft 10 7 7 wegolwe 2134-22755 Back support 21 SUBURBAN CABINET PARTS (conVell 8457 981 88 150K ohmV, watt 10 20-21257.4136 Glass support channel 5164 72281 Food, R453 481 94 4100 ohm watt 10 C228 SWITCH PLATE 240 V FRONT 2D -21257-A135 Glass support IC 2138 only; 3106 11034 F101Escutcheon screws 8454 981 84 6841 ohm weft 10 HI BAND OSC / 6 ASSEMBLY 25H-11507 Gasket 14M-21510 Speaker cable (1131 GEAR R455 OBI 96 680K chin 142 watt 10 3106.21460 7101 Channel p1011ips screws 14164.22846 R456 9BI 64 1500 ohm 044 10 Speaker cable 125V 3206.21460.7133 Channel pkrIlrEss screws IC 1138 R457 10811115 IBA 11116 5'PM speaker 11131) only 0214 SWITCH PLATE Her.reetel Hold 6,4,01 100K only) 06m IBA 19927 8" PM speaker LOW R -F SEC 25M-27756.1 Al 19 Mask To, ng knob TENSION SPRING 6.3V AC C20113 8458 9131 96 crises watt. 10 S13-27617 680K 2SM-22756-A135 Masi IC 1138 only) R459 9E12 14 10K ohm1 watt. 10' 58 21613 *Oroe and volume 'mob LOW BAND 200-22559 Escutcheon assembly C2I7 R460 081.90 220K ohm. V? watt 10 56.20755.29 Star knob (Includes 10 !ferns below) 5B-13047 5,c stabdifer knob HI R -F SEC 16' -LINK SPRING AGO ANT TRIMMER Transformers, Coils SC.22535 Escutcheon 201-10237 VHF burlarn antenna LINK 100-27600 1400 114 22303 Rot, Detector transformer 0141 plate and pulley assembly 200-12918 Cab,net back aosemble 430-22611 Push on fas1entr11 used) C207 1401 12C 27508 Aud,o Output trweslorrew (Includes 3'terns below) C 2 0 I A 60-22589 VHF dial scale LOW R -F PR//6 FRONT GEAR 7402 726a 18741 Vert,cal Oscillator iransfcrre, 23122762 Cab -net, back HI- BAND 1403 I2C 10161 2 rransforw, 6D-12590 UHF door! scale 20.72710 lee cord mounUng bracket -FRONT SHAFT Raytheon crest 1404 120 22586 F,lemon1 transformer SC 22397 144417395 Lree cord and 'slugs C212 12AT 7 6 BZ7 ANT TRIMMER 7405 11001 201.17691 041.ti..,, yoke assembly 21,4 22517 Retainer spring 513422948 Plasfrc emblem H/R-F PR/ 1341 12511 Bead 0114.0 151A-22758 CRT.shield fi 8444 445 BOTTOM COVER C44I I 200 22603 Pointer pad and bei 130-11961 Push on lasleeer Nun 3.Tap VI* Toner View Figure 4.lothee. VHF Toiler View

An Editorial Service of CALDWELL-CLEMENTS, INC. 480 Lexington Avenue, New York 17, N. Y. PLaza 9-7880 An Editorial Service of CALDWELL-CLEMENTS, INC. 480 Lexington Avenue, New York 17, N. Y. PLaza9-7880 HORIZONTAL RINGING COIL MODELS CONTAINING ALL CHANNEL UHF TUNERS February 1954 The horizontal ringing coil (L400) should be ad- TECHNICIAN justeda,follows, When the letter "U" appears in the model number, the receiver contains an all channel UHF tuner in addition to its VHF facilities. CIRCUIT DIGESTS 1. Short out tne ringing coil with a short jasp- er wire.

2. Set the horizontal hold control to the middle Fa hoe of its range, and leave it in this position during the 68270Ra/107A 508 SECTION 2 ',JUND I F codAUDIO steps that follow. T200 Ga06 GANG OUTPUT Connect a V1VM to the pin No. 2 grid circuit lif mCc, Pr...6 ALWWTPoT TRANS. 3. 0 V of the horizontal eultivibrator, do as to measure the 33 .75 09562e -V IX voltage between this point and ground. --4 luau. _ei31 LZU TTAW .005

-11 L. With the receiver tuned to a TV station, ad- 01 WV just C421 (located on the rear of the chassis) for 4 1 volt on the meter. If a reading of 1 1 volt can be ZE. 10..m COe approached but not quite reached at one extreme of the H200, 1 0051 1,105 2138 C421 adjustment, it may be necessary to set the hori- 1.028 zontal hold control slightly to one aide of aid - 71 Par HERO, position to obtain one volt reading. 800 C200 -= CONTROL -7 T -1- UHF 5 R205 r'4.14'r : 27K 5. Remove the jumper from across the ringing coil. 2' 7.5 L 4C07 .005 30 Adjust the ringing coil for 4 1 volt on the meter, . IIpos and check the adjustment by 'witching to another chan- ATOP nel and then back again. The receiver should pull in- "< e827 6 to horizontal synchronisation on all channels 32 02 oo t50 COOS $005 0326 ° 5308 J1 RSe 000 050 -- C309 470 12807 yc 300 :Do05 470 IL,LI (TNT --"""BRIONTNESS 005 X 6C136 6C86 Ri ALIGNMENT 6CK T300 --- T301 7; UHF.. I ST. IF AMP, 218.)if .0 ie. IE AMP 1 T302 ALI474ENT TOOL ouT20.0 059 MOST 5r --95m -e005 kI I-1 liemoo ON 300 1303.7N 114.,J4.. 11N, '2.127:347, To adjust the slugs in the common I -F transforeers ° 5 000 R. TERM a special tool is required. This tool must fit into 30o 050 3: I C302 7 p19). the .035" x .093" slot in the slug. An incorrectly 5 7722...,-k- NF. / .69 REAR 80.1.10 A)P- 3069v designed tool will cause chipping of the slug. A 24 R; , L 310 ,8307 OF ',M304: -IA 1- woo TCSIVO PUNT :II= so L3'09s 116-21-0 suitable tool is stocked under Westinghouse part ntm- 7i NNF RRE ni;-;r- ' w ER C 03 ber V-8345. Rots ?ScO< - BOO t ,o 37v "'" TOP mer _ 2 2 L302 L506' 11(i/ T -8 1312 BOTTOM /, e,5 CCNMON I -F ALIGNMENT PROCEDURE VIE W CR..;Tq- 'SC R 32.7G ZOOK VIDEO 'SEE S:9-0 49i 8325 TEST 66-- B 1}3. / NOTE 6 31 CONTROL 1000 The common I -F system uses over -coupled I -F trans- a "°43 POINT R26 H313 1.56 formers to obtain the required band width. In the 26.P 60, WV P -P60.1, 60% alignment of this type system, the visual method of OON; rp'1. v&LIES OF ALL CAPACrTOR6 IN Flo Tom, A sweep generator stage -by -stage alignment is used. ARESHOWN in C3.2 2 SECTION 3 VIDEO is used to develop the I -F response curve on the os- FOS; cilloscope, and an unmodulated signal generator (marker) 470 L1000 - tC.02 L.TERN T.005 is used to provide spot frequency indications on the SECTION I R -F 20 6 P 60% ( ---- 5049 :eozn 1",407 F BL7C I ceos 6 I2AU7 64U6 681(5 6AU6 Mt 12807 2200 oiJk M IS 3 6 vER-rnIUL 1,34 6ost Ili u VI VERT. OUTPUT IE R40 9 VERT. MILT I . svat 5E9 AUDIO OUTPUT CL OPEN 50000 DETECTOR 010E0. AMP O m, ,c, ' With some of the I -F transformers, peak. may be 0448A400 271c Z400 loose6 --11' "52' 12Ho=r obtained at two positions of the adjustment slugs. If 5 3 . .4 . 030, 2900 -1(406 . C406 5 ' L5,, al 221 at. 2.2---1 -. I F.,,T transformer is badly out of adjustment, it is advis- 2;.'s&'T 7%0 I TRANS. C400_, .404 -31p 1 R.* 2500 t_ able to turn the slug out (counterelockwiee) ae far as 8. T #-,'1,1'.'W ER''''''.- ' 11 1,2 1,, AT 7 8 "°5 ` 4 0, 511 possible before beginnin, alignment. Than turn the cSos E. C011gt R2Ce 122. .002i.05,i..005J ,,,,, , , liI Pcl, 00,m 5 ass 9 COmiRce slug clockwise until the first peak is reached. This .03 .8a procedure. is recoonended to obtain the correct peak fo_WS 6 6C86 6 C B6 6AU6 001 F Iii ! ZITIAm09 lAuUll. ,.Ofi"-Ac ctili/ ------1---- - 5 '1'-.!°'- :,:el, 217 ! C""-. 5'!11 --1- "01 ratner than an undesired second peak which is some - T.." Et-fhKOC = 6C4 f!"" 2 2471 5 (T14i4 3 4 L502 3 L503 - tines obtained when the slug is turned farther clock- 5 SYNC. CONTROL NOISE CLIPPER 2'Z''1,i1A _C".;=a00 ), !Ii!0 /-- '"dh-r* Cl!°8'(-1.6%1991 TT4 2460, 8502 400 SYNCAp vERT, GIN. =__ 580 560 wise. - 0 0 LIGHT FOCUS CONTROL .0 ...., L508 p663. C440 ( , WN 3 NOL G02 t' !--1-710'5 c 508 FOCUS Met 7N . VW 6AS 4G T g.,,r 270 °.°:14 I , ...'''. .0 005 6AS4GT r COIL sv 434 0....,...y, 6424 CPC" -Mr - 4.76 1,46 r- _1_ mOR4. 2_61-1.7GT3 6CD6G 60045T 6AX4GT 5406 SOCKET 8452 11000 -. DAMPER 02 fit,A GC 4.7N 3606rIFM-0-! -vEmrOut PUT HORQ_CUTPuT DAMPER 15. 25v gE=11 C432 e(412 7 3/''14 -- L '17i?- 590 *ORME

G. 60, a 4- 1B3. 00 1200 3/5 jt _AEC T.: t,344010 PLUG 8 POwER TRANS. C503... 5 600 5 8 .5,50 IL. --CAW eo: d 0500 1 1 PRONG i400 LC419 401 Ice 5U4G 5U4G Rm6m6 L4443 1 5.014.55, v.v.ROOT 74C" ...OK - 2 385v 30 12 c°'lLeicele 6CD6G I AM OCTET 0 CS02A - C30 0 P. 44L. 40 a Fig. 5 - Oscilloscope Connections 50 6-6 \ 22x "360' 220 x 1J1W81, M . 6415, C425 0025 sa8P-1; zA .1.1. -411- NOTES. 6501 I 6AS4GT 01 14 00012. A.F C. .25 OM ,.VOLTAGES Vo LLVAR. AITH GONTROI SETTING. I M1 150 X4GT Cr 0- 84 THE ALIGNMENT PRCCEDURE TO BE JS® IS GIVEN LN THE SW 500 -,-.C42 Pen 00011.5 - 542 ,10125 . - FOLLOWING STEPS! mOTURF GONTROI OFF ON IN IM II! 04.0 4.36 1 VERT. .L0 CONTROL 21 _Lcers 210K, :KrOTH 1 1. To avoid undesirable beat response during VERT. L CONTROL 6 C: 390 = I 433 006 I alignment, remove the R -F amplifier tube from its 2.PF - TO PE.*AmNORMS wi 4 AK. Kr...-Kr ff.!EN IR.. "NW . 4 SIGNAL C414 C 4 i6 Ti. /TOT 11 socket and rotate the channel selector to channel 13. WVA/ THE CATHODE OF C.R. /.A Pf ENTROLSSET rOR NCE/MAL PK. TURF . .01 , _,131 C422 3.RIPTS 7,1RANCF ANO RESPONSE 0, TEST.31,16mEmT MA 6 ,AJSE SOW 3A116A,CNS 6F THE 4EA6T6 .PEAR vCLTAGE RF ADM, "..21* 0g4/MI" G4441 5 CONTROL' .06-4111 2. Connect the vertical input of the oscillo- VOLTAGES MEASUREDFROM CHASSIS 60001.0 USING A 20,000 O.., VOLT METER AND NO SIGNAL INPUT. READINGS5001.0 Li _L. scope to the video test terminal (point "B" on Fig. 3) BE .SSHOwN :1" 20 PER CENT. 15750 . v4.P _Lc4.3 through the decoupling network shown in Fig. 5.The 5. ALL CAPACITANCE VALUESINRFD. AND A0 LRESISTANCE VALUES IN OHMS UNLESS OTHER wi SE SPECIFIED. T A, 6. 24. CHASMS USES24C PRA on 24TP4 AND2,-CHASMS USf 5 2 N0 ExTERNAL CROW,. COAT!.USED WITH 2mP4. oscilloscope horisontal input should be connected to - T. USOGUHF CONTINUOUS TUNERS the sweep (synchronizing) output from the sweep gener- THERE 5 60 INBOARDSOCKETON RECEIVE,. (FACTOR, R STAB, CO) MR+ stor THROUGH WELL SHIELDED LEADG. Turn the sweep con- SECTION 5 POWER oldFILAMENTS SECTION 4 SWEEP trol on the oscilloscope to the "x" or "off" position.

3. Connect the negative terminal of a 9 volt bias battery to the AGC line (point "A"), and connect Models: 1-1-815r24 the positive terminal to chassis ground. and H-8171[214 19. Make certain that the curve corresponds to Fig. II. Hake certain that the response curve coin - NOTE. IFk SIGNAL GENERATUR IS NOT AlAILA4LE AND L. Couple the marker generator output to the 7. Icetune the plate circuits of the 1st and 2nd The 44 me. pip must strike the center of the flat cidee with Fig. BA, using the varker to check at the THE RECEIVER IS LOCATED IN A SUM:, 31,AAL AREA WARE 8B. sweep generator output so that the two signals are IF amplifiers by attaching alligator or similar type response region, the 42.25 mc. and 45.75 mc. points appropriate frequencies. The Lh mc. pip must strike ADJACENT CHANNEL SOUND INTERPERDICE OCCURS, 1302 CAN applied together to the points specified in the steps clips to pin OS of the 6C86 let and 2nd IF amplifier must have heights, and the 43 me. and 41 mc. the center of the flat response region, the 42.25 Tx. BE ADJUSTED BY TUNING THE RECEIVER TO THE CAANNEL ON equal that follow. Some sweep generators have facilitiee tubes. USE CARE TO AVOID SHOCK. this step is neces- points must here equal heights. Re -adjust the primary end 45.75 me. points must be at equal neicjits. Re- WHICH THE ADJACENT CHANNEL INTERFERENCE OCCURS, CARE- for oonnecting the marker output dirottly1060the eeryto avoid absorption of the signal that is applied and secondary of T301 if necessary. adjust the primary and secondary of 7302 if necessary sweep generator. With ..;her sweep generator., the to the 3rd IF grid. FULLY AD.P.13TING 11E FIN! TUNING CONTROL TU ITS CORRECT WESTINGHOUSE to obtain these conditions. SETTING, AND ADJUSTING 1302 TO THE POSIT/ON WHERE THE marker can be coupled to the 'weep by wrapping few 20. Remove the defusing clip from plate of the let ADJACENT CAANNEL SoUND INTERFERENCE IS ELIMINATED. turn. of insulated wire around the center conductor 8. Adjust the oscilloscopeVerticalgain and the -F amplifier. of the sweep generator output cable and connecting sweep generator output level to obtain curve on the 12. Remove the detuning clAm that were attached. ChassisAssembly IA. Attach a detuning clip to the plate of the The loos, coupling in step 7. the marker generator to this wire. oscilloscope. To avoid distorted curve, the recom- let IF amplifier tube, and remove the amplitude modu- 21. Move the sweep output connection from the grid obtained in this manner is desirable because EXCESSIVE mended practice is to use maximum oscines,Opeverti- of the 2nd I -F amplifier to the grid of the let I -P V-2250-1 13. Disconnect the sweep generator fror the ,,rid lated signal generator connection,. MARKER SI1NAL INJECTION WILL nISTORT Tdi RESPONSE cal gain and only enough sweep31011amplitude to ob- amplifier, and connect the grouni si"e of the cable CURVIS. tain a good curve. of the 3rd IF amplifier. 17. Connect the high side of the sweep generator as close as possible to the gro.nd point for the 1st I -F amplifier tube. Connect a signal generator that hasanoutput output cable directly to the control grid of the 2nd IF 5. Adjust the sweep generator for center fre- 9. Set the marker generator to 44 me. with the 1.4. Technician of .02 volt or higher to the gridsthe 1st IF ampli- amplifier. Connect the ground side of the cable to the quency of 44 mc. with sweep deviation of 10 mc. output attenuated until the marker pip is barely vis- Detune L103 located on the tuner by rotating fier, "high" side to the grid and ground side to the chassis partition os clop as possible to the ground 22. ible on the curve, and adjust the primary of the 3rd Otherwise, tne chassis. Adjust tne signal generator to 47.25 me. point of the 2nd IF amplifier tube. it several turns counterclockwise. 6. Connect the high side of the sweep generator COMMI -F transformer, T302, until the 44 mc. marker setting of 1.103 will affect the eavoshape in the fol- CIRCUIT DIGEST output cable directly to the control grid of the 3rd pip is at the highest point on the response curve. amplitude modulated, and increase the output until a 18. Adjust the primary of the 2nd common I -F trans- lowing step. I -F amplifier, and connect the ground side of the cable sine wave response is visible on the oscilloscope. former, T301, formaxieulmheight of the respone, curve to the chassis partition as close as possible to the 10. Adjust the secondary of T302 to make the top at 414 sc., and adjust the secondary of 1101 to make ground point for the 3rd I -F amplifier tube.Keep the of the response curve symmetrical. 15. Adjust the adjacent channel sound trap, L302, (Continued on reverse side) the top of the curve symmetrical. leads from the cable as short as possible. for mini.im response on the ot.c.iloscope.

AnEditorialServiceof CALDWELL-CLEMENTS, INC. 480 Lexington Avenue, New York 17, N. Y. PLaza9-7880 115 ALIGNMENT CHARTS February 1954 WESTINGHOUSE Chassis Assembly The information in these charts is condensed from the foregoing detailed information as a convenience V.2250-1 to the service technician. It is recommended that the detailed information Lie studied before using the charts.

TestraisiA CIRCUIT DIGEST COMMON !-F SECTION Rotate the channel selector to channel 13.

Connect the oscilloscope to the video test terminal, point "B" on Fig. 3,A T CHNICIAN* 115 through the decoupling network shown in Fig. 5. Connect a 9 volt bias battery to the AGC line, point ''A" on Fig. 9. Couple the marker generator output to the sweep generator output. In the steps that follow, use the marker to check the response curve at the frequen- CIRCUIT DIGESTS H.F. 0SrILLATOR ALIe111,PNT PROCEDURE cies indicated on Fig. 8. If the 61B oscillator tube is replaced, the dif- In This Issue (No. 18) ferent inter -electrode capacitance of the nee tube may Alignment Step Signal Remarks Adios, - Circuit Digest No change the oscillator frequency enough to necessitate re -alignment of the oscillator. 1. Remove the RF amplifier tube. ADMIRAL 111 2. 44 mc. ....mo to Coct detuning clops Prr.of 1301 formax. re - Chassis 20A2, 20A2Z and 2002 Alignment of the oscillator on the high band is 3rd IF grid to1stnne A Ind IF plates sponse andsec.of1302 accomplished by adjusting the brass slug located ad- for symmetricolcurve shown GENERAL' ELECTRIC 113 jacent to the vernier drive wheel on the front of the on Fig. 8A, C tuner.Alignment of toe oscillator on the low band is Models: 2117, 2118, 21120, 21121, 21C dc,..mplished by adjusting the brass slug on the lower 7. 17.25mc.amp!, Use suit gegen,signal 1302 for min. response 225, 21C226, 21C227, 21C228, 21C229, RAYTHEON These slugs can be adjusted from rude modulated to to produce s.ne wave 114 front of the tuner. 1st IF grid response 21C230, 21C231, 21C232, 21C233 the front of the receiver without removing the chassis °.`.'c'11.- Chassis 21111: Models. M -2131A, C -2137A from the cabinet if a non-metallic tool similar to that scope. and C -2138A MAGNAVOX 112 shown in Fig. 7 is used.The guide on the end of the d. 44 wc. sweep ro Connect detoning clip Prt.of1301formax. re. tool is helpful in seating the tool in the screw slot. 2nd IF grid toI srIF plate sponseand sc.ofT301 Chassis 108A series: Models CT, CU 8 CMU WESTINGHOUSE 115 The adjustment procedure is as foliose: for symmetrical Curve shown 401A; CT, CU & CMU 402A; CT, CU & CMU ChassisAssemblyV-2250-1: .n Fig. 88. Models 1. Set the fine tuning control to the middle of 403A; CT, CU & CMU 404A H-815724 and H -817K24 its range by rotating it until the arrow near the edge d4inc. weep to Detune L103 before Pr..of7300 he mare of the fine tuning drive wheel is straight up, and Ist IF grid adrust(ng 1300 sponse andsc.of1300 keep it in this position during the following adjust- for synevon real curv ments. A. 44 me. sweepto L103 for "suck -out" at I., IF gr,cl 44me. (centerofcurve), 2.Set the channel selector to the highest of the low band (channels 2 through 6) stations operating in See F og. 8C. Replace the RF amplifier robe your vicinity. 4575.4 40115 42 2545 8. 213 mc. sweep ro Fine toning set ro mid. 1300 I c, symmetrical curve For complete Index to all earlier Circuit Digests, see main section of magazine 3. Peak the low band adjustment slug (L102) for Fig. 8 - Response Curves the best picture detail. antennatermonals '11°95 and L301 Ice min. 41.25 mc. through nelwori, mocker ornoidude. See Fog. of Various Stages of h. Set the channel selector to the highest of the 130 Alignment high band (channels 7 through 13) stations operating in your vicinity. 29. Couple the marker generator output to the 3. Apply a strong signal to the receiver, and ad- sweep generator output by using the loose capacitive just the quactrature coil (L202) for sexism program 5. Peek the high band adjustment slug (1.101) for coupling provided by one turn loop, or connect both sound. If peaks occur at two different positions that the best picture detail. the high side and the ground side of the marker genera. are widely separated, use the one that occurs when the tor cable to the receiver chassis.Loose coupling be- slug is farthest counterclockwiee.If two peaks occur 6.Check the previously made low band adjustment,

150A tween the marker generator and the receiver is desir- within a narrow range of adjustment, sufficient signal and if the tuning has changed repeat steps 2 and 3. SOUND I -F SECTION AND 4.5 MC. TRAP able to avoid distortion of the response curve. is not being applied to the receiver and/or the quieting COirraEOANCE 0, Swree CABLE control is not net at the proper position. 30.Set the channel selector to channel 13 and Connect the signal generator to the video test terminal (point "B" on Fig. 3) through a .001mfd.capacitor. the fine tuning control to the middle of its range. 4. Reduce the signal to its lowest useable level Signal Gen. 10 52 and adjust the 1.5 mc. IF slugs (1200 and L201) and the 31. Adjust the 'weep generator output to the Step Frequency VTVM Connections Remarks Adios, - ,51 56A 160, lowest level that provides a usable response curve on crattrature coil (1202) again for minimum program sound. SerCND DETECTOR LOCATION stn0. the oscilloscope, and adjust the marker output so that If peaks occur at two different settings of the slug, I. 4.5 me. or. RF probetopoint -C" Use strong signal from gen- 1303 for rAnrrnurn roAage the marker pip is barely visible. use the peak that occurs when the slug is farthest The second detector (11161 or C6706 crystal) and modulated IS..Frg. 91 and common !rater counterclockwise.Recheck adjustments at the lowest lead to chassis. useable signal. level. its associated components are located in the 3rd IF Fig. 6 - Impedance Matching Network 32. Adjust the 1st IF reactor, L300 for a sym- transformer shield can. The crystal, 1304 and C312 1. 4.5 Mc. FM metrical resnonae cone. Acres. volume conool Use strong signal from yen- L202 log mon.morn ovrau, can be replaced without installing an entire new 3rd 7.5 Kc. Der. erator 5.Apply very weak signal that allows noise to IF transformer assemblz. The replacement should be 33. Set the marker generator to 11.25 mc., and be heard and adjust the quieting control (R202) for exactly the sane as the original part.This applied 3. Some as step 2 Some as step 1 Useweakestsignalfrom L100. 1201 and1 202 to (Continued from reverse side) adjust the 41.25 rec.sound trap, L301, to minimize the minim noise.The position at which the noise is to both its electrical characteristics and physical general.. InfiailllunlpUlpul minimized depends on the strength of the signal;there- ctimensions. aplitude of the marker pip. In the event that the maller crystal is 4.5 Mc. AM 23. Adjust the primary of the 1st cannon IF trans- fore, the weakest useable station in the area should be not available and the larger size 11461.4 is used as a 4. Some as step 2 Strut.with weak signal on Greeting control Ice dip to former, 1300, for maximum height of the response curve 34. Using the marker generator at 11.25 Inc., 12.25 used for this adjustment.This control determines the replacement, the 11461 must be mounted vertically so that 30: Mad. crease as adersonentis Imo. at 41 mc., and adjust toe secondary of T3o0 to make the mc., 1,3 mc., 44 mc., 15.75 ec., and 17.25 mc., see that AM rejection characteristics pf the sound system, and the shield can be replaced. made. top of Lie curve symmetrical. the marker pips fall as indicated on Fig. PD.If the it. correct setting la normally about mid -position. DO curve is satisfactory on channel 11, all other channels NOT LEAVE ThE Q lIETING CONTROL SET AT ITS MAsIMUM COUN- 21. Adjust L133 so that the dip or 1.suck-outs should aleo be satisfactory. TERCLOCKWI.E which it produces on the response ru. e is at 4.. re. (center of curve). 4.5 MC. TRAP ALIGNelaT PROCEDURE 25. Make certain tipit tie curve corresponds to _op, DE Fig. 8C.If the marker frequencies fall at the cor- 1.Connect the high side of the si,nal genera- rect points, no transformer re -adjustments are required. tor to the video test terminal (point "13. on Fig. 3) through a .001 ofd mica capacitor, and ground the low 26. Remove the sweep output connection from the side to the chassis. - -12 grid of the let IF amplifier.

2. Adjust the signal generator to 4.5 mc. (un- sr.00up 27. Replace the RF amplifier to e which was re- modulated). 111ACE r,,,2rrrrETA.,.10 moved ins, ep 1. The accuracy of this frequ-iicy is very important.If a crystal controlled signal generator ..115.2.* rttraom 1f2Crior +/X":40 13 not available, the frequency should be checked with 7-, 28. Adjust the sweep generator to channel 13 (210 an accurate frequency meter. Fig. 7 - Oscillator Adjustment Tool to 216 etc.), and connect its output cable to the re- rico rssi ceiver 11116511115 terminals through the impedance matching Aenlne 3.Connect the common lead from the VTVM to the network shown in Fig. 6.Keep the leads as short as ,r'r?or poesible. chaseis, and connect the R -F probe from the VTVM to the cathode of the CRT.This point is chosen as point 5C.. To use locally generated signals ulignmentt Note that this point is above ground potential and, When working with very nigh frequencies, tne im- therefore, the R -F probe must contain blocking capa- w pedance matching network is required because response 1. Connect anoscilloscopeor an AC voltmeter curves are of no value unless the sweep generator out- citor. put cable is terminated in its characteristic impedance. across thevolume control for use as an indicator. Any mis-ea'ch present results in standing waves which 4. Using a strong 4.5 cc. signal, adjust the 4.5 mc. trap, 1.303 for minimum indication on the meter. 2. Apply 4.5 nc. FN signal (deviation Approxi- "iFrorL S ( PEI may seriously affect the observed waveform depending C. upon the amount of eds-match. mately 7.5 kc.) to the video test point (B on Fig. 3). SOUND ALILTIMMT PROCEDURE 3. using strong signal, adjust L202 for maximum (ii11;) output. 11..,L...71. b. The sound system can be aligned using either 120 locally generated signals or a received TV signal. 4. Reduce the signal to the lowest level that will WESTINGHOUSE Since the latter method does not require signal produce an indication and adjust 1.200, 1.201 and 1202 generating equipment, it will be described first and again for maximum output. -1 P17' Chassis Assembly will he followed by the procedure using locally gener- IT V-2250-1 ated signals. 5. Apply 4.5 cc. At4 signal (modulated approxi- use an "err" signal for eligtvnent, mately 30 percent) to the video test point. CIRCUIT DIGEST 1. Tine the receiver to a TV station and connect 6. Beginning with a very low signal level, in- an attenuator between the receiver end the antenna so crease the generator output, while rotating the quieting that the strength of the Agnal .can be varied from weak control back and forth, until the signal level is such to strong. that the PM output across the volume control dips to 115 2n10 with rise on each aide as the quieting control 2.Set the quieting control (R202) located on the is rotated.Set the quieting control for zero output Fig. 3 - Top Vi-- of Chassis back of the chassis approximately to its mid -position. at this signal level. Fig. 4 - Bottom View of Chassis

Copyright 1954 by CALDWELL-CLEMENTS, Inc., 480 Lexington An EditorialService o Avenue, New York 17, N.Y. ALDWELL-CLEMENTS, INC. 480 Lexington Avenue, New York 17, N. Y. Kozo9-7880 capacitor replacements FOR SETS OF THE MONTH

ADMIRAL CHASSIS 20A2, WESTINGHOUSE CHASSIS V-2250-1 20A2Z, 20D2 Symbol Rating WestinghouseSprague No. Mf @ WVDC Part No.Replacement Symbol Rating AcInilral Sprague No. Mf @ WVDC Part No. Replacement C21313 C40911 30 @ 500/10 @ 450 C205 4 @ 50 67A4-9 TVA -1303 C4108 V-11535-1 R-1488 C207 60+40 @ 350/60@ 200/20 @ 150 67615-23 TVL-4609 /150+30 @ 50 C4118 C409 80 @ 350/100 @ 50 67C15-22 TVL-3722 C410 20 @ 475 67A21-1 TVA -1804 C216A 1 C436A TVL-4720 C502A 40+40 @ 450/30+30 @ 350 V-9891 MAGNAVOX MODELS CT401 A, ETC. C503A Symbol Rating Magnavox Sprague C320 10 @ 450 V-10293-1 TVA -1705 No. Mf @ WVDC Part No. Replacement C426 4 @ 50 V-4637 TVA -1303 C446 30 @ 450 V-6570 TVA -1711 C106 4 @ 50 270027-10 TVA -1303 Z400 Integrator Plate V-11192-1 105C1 C110 20 @ 350 270027-20 TVA -1608 C215 2 @ 50 270027-22 TVA -1301 C413 10 @ 350 SP. 270027-23 R-1468 C501 70+40+10 @ 350/50 @ 50270021-52S TVL-4659 TVA -T308 C502 20+10+5 @ 350/60@ 200270021-51 TVL-4620 TVA -1413 NEW! PC301 Integrator Plate 250186-1 101 C1

GENERAL ELECTRIC "E E" Chassis SPRAGUE "T -C" RULE Symbol Rating G. E. Sprague No. Mf @ WVDC Part No. Replacement C210 1 @50 RCE-090 TVA -1300 C302 1050 RCE-090 TVA -1300 C320 1 @ 50 RCE-090 TVA -1300 C401 90+40 @ 350 RCE-154 TVL-2637 C402 30+20 @ 350/100 @ 75 RCE-155 TVL-3629 C403 40+20+5 @ 350/10 @ 25 RCE-156 TVL-4621 Note:C210 may alsobe 10Mf5OV (G.E. #RCE-169). Use Sprague TVA -1304 to replace.

RAYTHEON CHASSIS 21 T1 1 Use this handy pocket-size Sprague Tempera- Symbol Rating Raytheon Sprague ture Coefficient Rule to find quickly the values No. Mf @ WVDC Part No. Replacement of stock N750 and NPO type ceramic capacitors C402 100+10 @ 300/60 @ 50 8C-22523 TVL-3574 to connect in parallel to equal a capacitor of C414 20 @300/T0@75/10@ 158C-22524 R-1487 C428 100@ 150 8C-22285 TVA -1420 desired intermediate temperature coefficient of C429 100@ 150 8C-22286 TVL-1423 the required capacitance. C503 50 @450 8C-22544 TVA -1713 C442 Integrator Plate 17A-22376 101C1 COLOR CODE CHARTS

Sprague makes more capacitors... in Complete charts for color codes on all types more types . . . in more ratings . . . of ceramic capacitors are on the back face of than any other capacitor manufac- this rule. turer.Send 10cfor 48 -page TV ReplacementCapacitor Manualto Get your Sprague "T -C" Rules now from Sprague ProductsCo., 65 Marshall your Spraguedistributor,ordirectlyfrom St.,North Adams. Mass., or getit Sprague Products Company, 65 Marshall Street, FREE 'tom your Sprague distributor. North Adams, Massachusetts. They're only 15¢ each.

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