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Í MAC glanced along the service bench to where Barney, his helper, was scowling down at a lone nickel in the palm of his hand. "What's eating you, Little Sunshine?" Mac asked. "If that is supposed to be your last nickel, and if you are putting on this production in the hope of getting a raise, well -" "No, not that," Barney interrupted. "I was just looking at the profile on this nickel and thinking that Lo the Poor Indian is rapidly vanishing from the American scene for the second time." "How do you figure ?" "Well, the Indian -head test pattern, or any test pattern for that matter, is rapidly becoming extinct. Soon you will stand more chance of seeing a flying saucer than of glimpsing a test pattern. Stations put them on only for a few minutes in the morning hours. Worse yet, they often employ this period to make adjustments on the transmitter. The net result is that you can never be sure nonlinearity seen in the receiver pattern, for example, is not actually being transmitted; and if you start to correct the pattern at your end, they may be doing the same thing at their end. While you're 'zigging' they may be 'zagging' ' "True, but why get all worked up about it "'Why get all worked up about it ?' the man says," Barney mimicked. "I'll tell you why: a whole TV service procedure has been built up around the test pattern. Reams and reams of paper have been devoted to showing the technician how to detect everything from shorted yoke turns to a fly standing on top of the horizontal 68 MAC'S RADIO SERVICE SHOP By JOHN T. FRYE "VANISHING AMERICAN" output tube plate cap just by staring fixedly at a test pattern. 'Study the test pattern,' preached the manufacturers; 'Study the test pattern,' advised the service magazines; 'Study the test pattern,' commanded the TV pundits in their service lectures and books; and now -no test pattern!" Mac chuckled at Barney's melodramatic vehemence. "There's a lot of truth in what you say, Red." he drawled. "No one can deny TV stations make with the test patterns like a circus con man manipulating the pea in the old shell game: 'Now you see it; now you don't.' Still and all, I think we can salvage some of the effort we put into studying those patterns for symptoms. "Especially can we do so if, in our studying. we took the trouble to look behind the test pattern symptom to grasp exactly why a particular circuit defect resulted in precisely that kind of pattern distortion. If we did that, we'd have little trouble in finding the same symptom in a picture that we taught ourselves to discover in a test pattern. Remember that after all a pattern simply presents a collection of typical picture elements all in one 'scene' so that it can be quickly determined if the set is capable of reproducing every sort of picture. If you have a quick eye and can concentrate on picture elements rather than on the picture as a whole, if you have made a thorough study of how receiver troubles affect the deflection and modulation of that flying spot of light as it traces out any design on the face of the tube, you can learn almost as much from studying an actual picture as you can from looking at a test pattern." "What do you mean by 'concentrating on picture elements rather than on the picture itself' ?" Barney wanted to know. "Well, suppose you are looking at Marilyn Monroe in a swim suit standing in front of a picket fence. The idea is to concentrate on the fence, noticing if the individual pickets stand out clearly and sharply even as the camera dollys out from the scene. If they do, the horizontal resolution is good, and -" "Say no more!" Barney interrupted. "There is a limit to what you can expect of human flesh and blood." "It will not always be that hard," Mac said with a grin. "For example, you can learn a lot about vertical and horizontal resolution by watching the stripes on a football referee's shirt as he moves about the field. If you can still distinguish these vertical stripes when he is standing upright a long ways from the camera, the horizontal resolution is good. On the other hand, if the shirt looks a sort of tattle -tale gray until he stoops over to pick up the ball and then the stripes stand out clearly, you will know that the vertical resolution is superior to the horizontal resolution -as is quite often the case. "Other tests are the picket fence I mentioned, checked material, and brick walls. As the camera moves away from checked material, the speed with which the individual squares start running together is an indication of the resolution of the set. Some plaids will look like striped material at a little distance, and the way in which the stripes run will give an idea as to which kind of resolution is best. Mortar cracks in a brick wall also furnish reliable information. When the horizontal resolution is good, the short vertical lines between bricks will stand out as clearly and whitely as the long horizontal lines; but when this resolution is poor. the vertical lines will be dimmer and more of a gray color." "How about linearity? I never had much luck lining that up without a test pattern." "A bar generator is the logical instrument for this purpose, and since it is comparatively inexpensive, there is little excuse for the TV technician not having one. There may be a few times, though, when he will be called upon to correct the linearity circuits when neither a test pattern nor bar generator is right at hand. With a little patience he can still do it. Vertical linearity can be easily and quickly checked by adjusting the vertical hold control so that the picture drifts slowly downward and watching the vertical blanking bar as it moves down across the face of the screen. This bar should stay the same width. If it is wider when at the top than at the bottom, you know the picture is stretched at the top, and you correct this with the vertical linearity control. If the bar grows wider as it (Continued on page 116) RADIO 8 TELEVISION NEWS
Sete/t SHORT -WAVE Compiled by KENNETH R. BOORD ASPECIAL DX broadcast, dedicated to monitors for RADIO t TELE- VISION NEWS, will be presented over Radio Station 4VEH, Box 1, Cap Haitien, Haiti. operating on 9.685AV in the 31 -meter band, on Saturday, April 4, at 1145 (1645 GMT) and repeated the same day at 2345 (Easter Sunday 0445 GMT). The program will consist of transcribed greetings and a program of Easter organ melodies played by your Short -Wave Editor. Reception reports will be welcomed from any place in the world; correct reports will be answered by an attractive new QSL card. An International Reply Coupon should be enclosed with your report; if you want your QSL card by airmail, enclose sufficient IRC's to cover the cost of one unit of airmail postage to your address. At the time this was compiled, 4VEH was still seeking a clear channel but hoped by April 4 to be using 9.667 for its daily "morning" I EST) transmissions and 9.710 for its (Sunday only) "evening" (EST) transmission. Will Verify M. L. Gibson, W7JIE, Maintenance Technician, AAH, of the Alaska Communication System, says he will be glad to verify all correct reception reports on stations of the System by letter. provided that a self- addressed envelope with sufficient return postage is forwarded with the report; otherwise. reports will luire to be filed without reply since the System has no funds for either QSL cards or postage for verification replies. AAH is owned and operated by the United States Signal Corps: the headquarters station is located in Seattle, Washington; branch stations are situated throughout Alaska. Several types of transmissions are made, including broadcast; voice transmissions may be either in clear language or in one of several types of privacy. Transmitter powers range from 2.5 kw. to around 20 kw. Frequencies used are from 67.5 kc. to 19.635 mc. in all bands and with various types of radiation, dependent on the frequency and necessity. Normal direction of transmission on rhombic antennas is northwest towards Alaska; conversely, Alaskan stations transmit southeastward toward Seattle in many cases. ' When circuit conditions are non - operative or when a frequency change has been made and is being re- established, the radiotelephone circuits all April, 1953 utilize an identifying call tape in clear language. Normally, the radiophones operate from 3 mc. upwards with varying powers. Broadcast transmissions are made from time to time, relaying networks from Seattle to Alaska. Normally, these transmissions are preceded by one hour of test music and identification. The usual frequencies for these broadcasts -depending on the time of day -are 4.305, 6.910, 10.720, 11.995, 14.8675, 17.500, and 19.510. There is no regular sched de for any of these broadcasts. Reception reports for these stations -accompinied by a self -addressed envelope ivi 'h sufficient return postage - should be sent to: Attention: Maintenance, Room 525, Commanding Officer, Alaska Communication System, 550 Federal Office Building, Seattle 4, Washington, USA. * WRH Available Now Of grei.t value to all DX -ers is the 1953 Edit ion of World Radio Handbook which is now available for $1.50, postpaid, direct from Ben E. Wilbur, 1000 Con iecticut Ave., N. W., Washington, D. C. s Radio Club Notes Sweden -I have just received the monthly )ulletin from the new Swedish club, Radioklubben Universal, Klorupsv igen 144, Trelleborg, Sweden; the publication is called "Etersvep," and has English as well as Swedish sections. Curren: QRA for Malmo DX -aren is Postfa2k 7026, Malmo 7. Sweden. USA -The Newark News Radio Club, which observed its 25th birthday on December 8, 1952, will have its 25th anniversary dinner party at the Crystal Brook, Eatontown, New Jersey, cn April 18; members from far and rear are expected to attend the evert, according to Irving R. Potts, veteran president of NNRC. s s This Month's Schedules (Note: Beginning around mid -April, some stations may go on summer I Nute: 1' lives otherwise indicated. all time is expressed in American EST: add 5 hours for (111'. `New," refers to newsvasts in the English language. In order to avoid confusion. the 24 hour eiwi La-, been used in designating the times of broadeasls. The hours fr midnight until noon are st own as 11111111 to 11111 while from 1 p.m. to mi, night are shown as 1141111 In 241111.) The symbol "\"' following a listed frequency indicates "t ar'ing.'' The station may operate either ahovi or brhnv the frequency given. '.A" means frequency is approximate. schedules; in such cases you may find schedules one hour earlier than listed herein. -K.R.B.) Afghanistan -Kabul Radio, 9.975, noted 1050 with news, signing off 1102; on Sunday extends schedule to around 1130 with listeners' requests for popular music; when closing says "Goodnight, good luck. good listening;" announces as "Kabul Calling in the International Service of the Afghan Broadcasting Service;" opens daily around 1045. (Pearce, England) Also noted to 1130 Wednesdays when extended schedule features classical music, by request. (Ridgeway, South Africa) Albania -ZAA, 6.55A, Tirana, noted at good level from around 1200 to closedown with clock chiming 10 at 1600, then choir singing to 1605; is not parallel with 7.850A which has a different language schedule. (Ridgeway, South Africa) Algeria -Radio Algerie, 6.160, noted 1435 with news in Arabic. (Pearce, England) Andorra -Radio Andorra, 5.990, is scheduled 0600 -0900, 1230 -1900. (WRH) Anglo- Egyptian Sudan -Radio Omdurman announces outlets now as 30.5 m. and 48 m.; however, is heard in South Africa on 9.846V and 6.438A (moved from 9.737A and 7.000A. re- spectively); English on Fri. 1230 -1300, Sun. and Wed. 1115 -1130. (Ridgeway. South Africa) The 30 -m. channel is heard afternoons (EST) in USA. (Chatfield, Bellington. N. Y., others) Angola- Luanda, 11.862, noted to 1730 closedown; the 9.470 outlet closes 1630. (Pearce, England) Radio Clube do Bie, CR6RD, Silvo Porto, is back on 7.584; scheduled 1200 -1545; good level, some CWQRM. CR6RF, 9.502. CR6- RB. 5.045, Benguela, noted 0630 -0800, 1230 -1500; the 9.165 channel is not in use now; CR6AA. 7.042, Lobito, is heard weekdays 1300 -1630 (listed also 0015 -0100) and 0530 -0700 with Portuguese program. (Ridgeway, South Africa) Argentina- Latest schedules from SIRA, Buenos Aires, list English daily over LRA, 17.720, to East Coast USA 1700 -1928; LRU. 15.290, to West Coast USA 2300 -0100. and LRS, 11.880, (Lund, Iowa, to England 1300 -1358. others) Australia- VLA11, 11.760, is heard occasionally around 1330 in beam to Central Europe; is usually good (Continued on page 108) 69
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T EVIS i N APRIL 1953 IN THIS ISSUE
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YOU PRACTICE COMMUNICATIONS with Ki
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I NOW...from D.T.I.s MILLION DOLLAR
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"I Read You Five." Welcome Words! H
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Get yourself on the beam to the BIG
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Look! New small size Adashaft Radio
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A LOOK INSIDE PROVES WHY PAY A SERV
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TELEVISION RADAR ELECTRONICS RESEAR
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BETA RADIATION GAUGING METHODS By G
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would have in controlling the proce
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is done, the meter on the Microvolt
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I voltage regulation', '.'. as well
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DECAY CONSTANT IN VIBRATING SYSTEMS
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I I (5000), and Curie point* occurr
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COAXIAL CAVITY TUNING ELEMENT Fig.
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Make your U H F circuits as simple
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(// Capacitors shown 21 /7 times ac
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RCA N E E DS E NGI N E E RS who won
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O N FREQUENCY CONTROL FOR MILITARY
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i Gpoßt i. NOW YOU CAN 4 pvRAVE ti
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known as the 5894 -A, because the c
Page 47 and 48: Ticnife "FILTER DESIGN DATA FOR COM
Page 49 and 50: Converter Calibration (Continued fr
Page 51 and 52: For opportunities within your reach
Page 53 and 54: Sweeping the Country! Collins Audio
Page 55 and 56: ULTRA FAN series-Complete VHF -UHF
Page 57 and 58: 1 029 Leonard C. Lane, B.S., M.A. ;
Page 59 and 60: A Transistor of point -contact type
Page 61 and 62: PH I LCO TESTERS Now Yours on NEW S
Page 63 and 64: Mriiffffifff(i ( l ((( THE RADIART
Page 65 and 66: TRAIN FASTER- TRAIN BETTER- TRAIN E
Page 67 and 68: A ROBOT ELECTRONIC TURTLE Closeup v
Page 69 and 70: 7. Solder to the ends of the Fa " s
Page 71 and 72: THE semi -automatic or "bug" key is
Page 73 and 74: ' even a small wooden box may be us
Page 75 and 76: Fig. 1. The compact, versatile mobi
Page 77 and 78: access to a surplus TU -10-B tuning
Page 79 and 80: CHANNELS Pertinent frequencies and
Page 81 and 82: quency definition probably wasn't n
Page 83 and 84: conicals are usually stacked two or
Page 85 and 86: THE U T SPEAKER ENCLOSURE Design de
Page 87 and 88: a drop of 6 db -per- octave above 5
Page 89 and 90: Fig. 1. (Left) Front panel view of
Page 91 and 92: Fig. 3. Bottom view of the 30-watt
Page 93 and 94: A LOWR[SISTA NCE OHMMETER _ By J. P
Page 95 and 96: By HAROLD HARRIS Vice -President, E
Page 97: erticle, the results are not too fa
Page 101 and 102: dual triodes with the necessary int
Page 103 and 104: You, ecutiAtea a &LtAufoP4Lo ctZ& b
Page 105 and 106: The data that Launched Thousands of
Page 107 and 108: Te MANUALS SHOW YOU HOW. Here is vi
Page 109 and 110: NEW WIDE BAND VERTICAL AMPLIFIE Dir
Page 111 and 112: Indicates frequency of energized ci
Page 113 and 114: NAL TRACER KIT OCATOR AND WATTMETER
Page 115 and 116: Mod.loied or nwdc kited RF output.
Page 117 and 118: SUPERHETERODYNE High gain dual iron
Page 119 and 120: H. D. Suesholtz, General Manager, T
Page 121 and 122: It will count events occurring eith
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Page 125 and 126: Which Yo Want? Guet your FCC Ticket
Page 127 and 128: Code Practice Oscillator (Continued
Page 129 and 130: . =Ms or ...eel, u ' tically. topla
Page 131 and 132: 1 II{ Phono Equalizers (Continued f
Page 133 and 134: 1 BA" None None Top Top THE BEST IN
Page 135 and 136: What's New in Rac io (Continued fro
Page 137 and 138: 59 .n 89 60 .89 54.95 . .69 . 1.59
Page 139 and 140: a noted 0630 with news, strong leve
Page 141 and 142: Clearly ' lia) Radio France -Asie,
Page 143 and 144: le in any variable power supply, no
Page 145 and 146: . SI9.95 \I e \ With 1 \I I.IB . 1.
Page 147 and 148: denser (Admiral par number 65B6 -26
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nllent 95 D.e.198 e B d. Adjust the
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Antenna Measurements (Continued fro
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impedance" and is an import ant con
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- 1 Junius Heard with news 0730 on
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allo is French session 0630 on 15.1
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v IlIllIllIlli IllIllIllIll
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NEW TV PRODUCTS On The Market "TELO
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entire u.h.f. band. A sin ;le switc
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layout charts and floor arrangement
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Fringe Antennas (Continued from pag
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a theater TV in the frequency spect
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Receiver Change s (Continued from p
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:nrh BF "BASIC ELECTRONIC TEST INST
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S0.62 f tical and easily- understoo
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B2 IT'S TERRIFIC! Fig. 3. Circuit t
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h' SGP1 7867 Within the Indust.), (
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VARIABLE PULSE LIGHT SOURCE HUNGER
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completely new system of closed con
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p ice businessman sells time, know
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It is apparent from the information
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1 -Improving Ir71 vision Technician
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i 2 Rate 50c per word. Minimum 10 w
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Assembling the components of Raythe
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