QST Looks at Television - 1944
January 1945 QST Article
Did you know that you are likely a TLV? That's right, a Television Looker. The modern equivalent is CP - Couch
Potato. In the early years of television, TLVs were as fascinated with the device itself and the technology as
they were with the information being displayed. As this story tells, Hams were involved in TV transmission (ATV)
early on. I did not know that amateur television was banned during World War II. During WWII, all amateur radio
operations were suspended with the exception of those authorized to continue under the Radio Amateur Civil
Emergency Service (RACES).
of Contents]These articles are scanned and OCRed from old editions of the
ARRL's QST magazine. Here is a list of the
QST articles I have already posted. As time permits, I will
be glad to scan articles for you. All copyrights (if any) are hereby acknowledged.
See all available vintage QST articles.
QST Looks at Television - 1944
The "State of the Art" from an Amateur Viewpoint
T. Read, W9AA
For many years leading experimenters in the amateur ranks have interested
themselves in television and some notable work has been accomplished. Since Pearl Harbor all amateur television
has of course been discontinued, but the commercial broadcasters have continued to experiment and plan for the
future. QST presents herewith an account of present-day television as it looks from the amateur viewpoint.
Of all the electronic miracles which have been promised to the postwar world the most widely anticipated probably
is television. Ever since the early days of radio broadcasting the possibility of being able to see as well as
hear by radio has intrigued the public's imagination and every faltering step forward in this new art has been
eagerly hailed with the statement that "television is just around the corner." This great public interest,
accompanied as it has been by many irresponsible predictions of immediate availability, has not been an unmixed
blessing. There is no television equivalent for the crystal detector or simple one-tube receiver - even the
crudest early attempts at video transmission by means of rotary scanning discs required comparatively complicated
equipment - and most of the serious workers in the field have done their best to head off premature promotion.
The eventual place of television in amateur radio is not yet clear. As early as 1925 QST carried articles about
the scanning disc systems of that day and since then has consistently presented the facts about new developments
in the art when they seemed to offer possibilities for amateur use. At the same time the limitations and problems
still to be overcome have been clearly set forth, a notable instance of "debunking" being the article, "Television
- What About It?" which Ross Hull wrote in 1931.1 Late in 1937 QST started on a systematic development
program for amateur television. An introduction by James J. Lamb2 was followed by a series of articles
on modern cathoderay television adapted for amateur use, which were discontinued only when war put a stop to most
amateur experimentation. This report on today's television is not intended as a continuation of that series but,
rather, is an appraisal of the present situation as a whole, an attempt to shed a little light on what has
recently become a most controversial subject.
The studio staff at WABD during the televising of "Parisian Memories." It takes a full size crew to operate all
of this paraphernalia. The man in the left foreground is manipulating the microphone boom to pick up the
singer's voice without letting the mike show in the picture.
WABD has presented many interesting shows. Here is a scene from "The Boys From Boise," broadway musicomedy that
was transmitted complete with orchestra, chorus girls, and all the trimmings
The main control room at WABD. The large monitoring scopes have 14 inch screens and reproduce the picture in
black and white.
The control room of Studio A. The small monitors on top use the familiar 5·inch oscilloscope tube. The picture
is green hut these tubes serve the purpose until new equipment is available,
Which is which? One of the above pictures is from an original 8 X 10 photograph and the other shows bow it
appears after having been transmitted by television. You pick 'em out.
Turntables and main sound control panels at WABD.
A camera dolly carrying iconoscope camera, electronic viewfinder (using another green 5 inch tube) and power
supplies "for iconoscope, preamplifier. etc.
Fig. 1 - Television channel No.4, showing how the six megacycles between 78 and 84 are used by WABD. The video
carrier is amplitude modulated and has it. lower side band partially suppressed.
Television camera opened to show arrangement of parts. The iconoscope tube is at the upper left with base
including electron gun slanting down to the right. Lens equipment for focusing picture on the screen of
iconoscope is at the upper right. The bottom cabinet contains the preamplifier with the input tube placed as
close to the Ike screen as possible.
Antennas of WABD, station of the Dumont Television Corporation atop the 515 Madison Ave. Bldg., New York City.
The folded dipole is the video antenna, the doughnut is for the accompanying sound.
The transmitters at WABD. Panel at extreme left contains exciter and modulator for f.m. sound channel. Unit at
the right contains final amplifier for sound. The rest of the equipment is all video.
For the past many months the writer's principal duties have
been to attend meetings and read voluminous reports, anything and everything that might conceivably have an impact
on amateur frequencies. In the process he has been privileged to attend various panel and committee meetings of
the Radio Technical Planning Board, meetings of the State Department's committee on radio allocations, and the
recent hearings of the Federal Communications Commission. At many of these, television was the principal subject
and the heated discussions between adherents of the present standards and frequencies and those who want to use
more scanning lines and move to the u.h.f. region were strongly reminiscent of the 'phone-vs.-c.w. or high-vs.-low
power arguments in amateur circles. QST, of course, is neutral regarding the television controversy as this is not
an amateur matter. However, no dyed-in-the-wool ham can remain completely unmoved in the presence of a real good
scrap over technical matters, so we determined to find out "what the shootin' was all about." Through the courtesy
of Dr. Allen B. DuMont, ex-W2AYR/W2AHD, and Dr. T. T. Goldsmith, director of research for the DuMont Corp., we had
the opportunity to visit WABD and inspect a modern television station.
WABD in Operation
WABD is on the air three nights a week from 8 until usually about 11 P.M. Practically the entire staff of
engineers and technicians is made up of regular DuMont employees who are operating this television station on an
overtime basis in addition to their full-time job of war production in the plant at Passaic, N. J. As might be
expected, most of them are amateurs or have an amateur background,
While WABD operates under a commercial
license and many sponsored shows are regularly transmitted, the entire setup is still of a more or less
experimental nature. DuMont provides all of the technical facilities and personnel but programs are largely
furnished by New York advertising agencies who have gladly accepted this opportunity to gain practical experience
in the newest of advertising mediums. This cooperation has resulted in many interesting shows for the TVLs
(television lookers), a notable example being the recent transmission of an entire Broadway musical comedy
complete with orchestra, chorus girls, and all the trimmings.
Promptly at 7:30 P.M. we arrived at 515
Madison Avenue, New York City, and were greeted by Morris C. Barton, jr., ex-W4CRV, chief of operations.
WABD's transmitters, main control room, and studio A are located on the 42nd floor, while offices and studio B are
on the 2nd floor. The studios are somewhat similar in arrangement to those used for standard broadcasting but they
contain much more equipment. One wall is covered with scenery - back drops, stage furnishings, etc. Overhead are
banks of incandescent flood lights, the type in which the reflector is a part of the bulb itself. Two camera
dollies, small rubber tired trucks which carry iconoscope camera, preamplifier, power supplies, and camera man,
trail a tangle of coaxial cables and power wires behind them across the floor while other cables run to an
enormous spotlight and 'to the microphone which is suspended from an overhead boom, a la Hollywood. It takes a
full size crew to operate all of this paraphernalia. In addition to the people normally used in any broadcast
studio, such as sound effects men and announcer (in television a charming young lady), there are camera men, men
to push the camera men around on their rubber tired mounts, spotlight operators, microphone boom swingers,
property men to move scenery, announcement cards, etc., and a couple of assistant directors. Camera men and
directors are "wired for sound" - they wear headphones through which they can receive orders from the principal
director in the control room.
Television employs many techniques of the theater but there are some rather
startling differences. Because the monochrome camera does not respond well to red, the lovely girl singer who was
about to go on appeared for work wearing dark brown lipstick. The scenery was painted in various shades of gray
which have been found by experiment to give the most natural appearance on the screen. The nonchalance with which
scenery was moved during the performance also was rather surprising until we realized that no stage curtain ever
invented could conceal such activities as well as switching off the camera.
We did not get to see the whole show as we were far too busy asking questions of the engineers and trying
to find out "what made the wheels go 'round." The part that we did see was highly interesting and well worth
watching. There has been much argument of late about the quality of present day television pictures. We viewed.
the WABD show on the control room monitor which operates directly from the coaxial line running to the transmitter
and on the main station monitor which picks up the program from the air.
Both of these use 14-inch tubes
and the picture appears to be about 8 X 10 inches or slightly larger. This is not nearly as large as will be
available on good home television receivers in the future - it is expected that a projection type set capable of
producing a picture 18 X 24 inches in size will have been announced before this article appears in print. It is
possible, .of course, to get close enough to the screen so that the line structure becomes visible but the same is
true of almost any kind of pictorial material. Moving pictures are very crude when seen from the front row and
world famous oil paintings cannot be appreciated until viewed from far enough away so that the brush strokes are
not predominant. From a normal viewing distance the 525 lines of present day television are not noticeable. This
is in no sense an argument against a greater number of lines. If better television can be produced we are all for
it, but the present version is good enough to make us put some of those war bonds into an envelope marked
To get back to WABD. The studio control room also is much like the
conventional b.c. type but with extra equipment and personnel. The sound control desk, which in ordinary
broadcasting is the center of attraction, here is relegated to one side of the room. In its place before the plate
glass window is a large console containing video controls, camera monitoring scopes, main studio monitoring scope,
small scopes which show the detailed characteristics of the various video signals, scopes which show the "shading
voltage" by means of which minor defects in lighting the picture may be corrected or special effects produced, and
in fact more scopes than we had ever before seen in one place. In spite of the fact that Dumont manufactures these
tubes W ABD has to get along for the most part with prewar equipment, all new production being needed for war use
As in the studio itself, the control room requires a large staff. One sound engineer is
sufficient but there are video engineers for each camera, a principal video engineer at the main monitoring
scope, and the program director who supervises the entire production. By means of two simple gain controls the
principal control engineer is able to make "lap dissolves," that is, fade from one scene to another, which would
be the envy of any Hollywood technician.
At the rear of the control room a large panel contains amplifiers and the synchronizing pulse generator which is
the heart of the entire system. This generator provides the timing, vertical and horizontal sawtooth voltages,
blanking voltages, and synchronizing pulses.
At WABD the camera man never lines up the picture by visual
means, Instead his viewfinder is entirely electronic, a five-inch scope in a viewing hood mounted on the side of
the camera and fed by a coaxial line from the control room amplifier. For this reason he makes no allowance for
parallax and there is no danger that he will cut off the heroine's head in a close-up. It is as though the
operator of a movie camera could watch the scene he was taking through the camera's lens system instead of through
a separate optical viewfinder, certainly a very real advantage. At present the camera viewfinders and the
individual camera monitors in the control room use standard 5-inch tubes which show the picture in varying shades
of green, only the large tubes make use of the new type of fluorescent material which responds in black and white.
Incidentally, the contrast and brilliance of the pictures on these black and white tubes was much better than we
had anticipated, although it is claimed there is still room for improvement. As is also true of moving pictures,
black and white are purely relative terms, the unilluminated screen of the scope itself being white. However, the
variations of brilliance between the illuminated and unilluminated portions of the screen do produce a very
satisfactory degree of contrast.
From the studio control room the program goes to the master control room
located next to the transmitter room on the 42nd floor. All video signals are carried by coaxial cables while the
sound goes over an ordinary wire system. In the master control room the program is monitored again before being
fed to the transmitter. In addition, master control switches between studios connect the special equipment which
permits movie film to be televised.
The transmitters themselves are mounted in typical broadcast fashion in a large steel console extending the
length of the room. Behind this imposing exterior, however, the rig looks strangely familiar, particularly to
anyone who has done much work on the v.h.f. ham bands.
In the transmitter console the f.m. audio rig
occupies the sections at either end and the video equipment fills the other five sections. WABD operates on
channel four - 78 to 84 Mc. The audio channel starts off with a crystal on 129.244 kc. and multiplies by means of
quadruplers, etc., to reach 41.875 Mc. in the f.m. exciter unit. Modulation is introduced through a compressor and
a pre-emphasis amplifier and is accomplished by means of a phase shift method similar to the Armstrong system.
After leaving the exciter the audio signal goes through an 807 doubler, an 829 buffer, a pair of 100THs, and into
the final pair of 450THs. The output, approximately one and a half kilowatts, goes to a ring antenna mounted on
top of the tower. The center frequency of the audio channel is 83.75 Mc. and the deviation is 75 kc. plus or
The video channel starts with a 4953.125 kc. crystal in a Pierce oscillator using a 7C5. After
quadrupling twice the signal is amplified and applied to the modulated stage, a pair of 100THs. Grid modulation is
used and the modulator consists of two HK257s. Three broad-band ClassB linear amplifier stages follow the
modulated stage. The first is a pair of 152Ts using a coil and capacitor in the grid circuit while the plates go
to a linear tank. The following two stages - use linear tanks throughout with hairpin coupling loops, all on a
rather massive scale judged by amateur standards. The driver consists of two water-cooled type 8002 tubes and the
final of two 8898 which are water cooled arid in addition have a blast of air blowing on the glass seals. The
final stage operates as a grounded grid amplifier, excitation being applied to the filaments while the grids are
bypassed to ground. This arrangement is much easier to drive at these frequencies than the usual system and nearly
eliminates the need for neutralization. The antenna for the video signal consists of folded dipoles arranged in a
cross just below the doughnut which radiates the audio signal.
The unmodulated video carrier is at
79.25 Mc. with an output power of approximately 6 kilowatts and has one side band partially suppressed. All of the
video amplifying equipment in the station is essentially flat to 5 Mc. but the signal that finally goes out is cut
off at 4.25 Mc. The disposition of the two carriers in the 6 Mc. channel is shown in Fig. 1.
QST has published many articles dealing with the theory and operation of television equipment so no attempt will
be made to cover the same ground here. The most recent of these, an explanation of iconoscope operation, appeared
in July, 1944.3 However, one feature of modern television transmission which has mystified many hams is
the method by which moving picture film of 24 frames per second is transmitted over a system employing 30 frames
and an explanation of the method may prove interesting. Actually this is not as complicated as it sounds. Because
of the interlacing action of the television scanning beam the picture is covered by 60 fields per second, that is,
the beam starts at the upper left-hand corner of the picture and scans alternate lines and then returns to the top
of the picture and scans the other half, filling in the vacancies left the first time through. Thus two of the 60
fields are required to completely fill in a single picture or frame. As this scanning action is continuous there
is nothing in video transmission which exactly corresponds to the shutter action of a moving
The conversion of 24 frame-per-second movies to 60 field-per-second television is accomplished
by scanning one frame of film for 2 fields and the next for 3. In this way half of the frames are scanned twice,
12 frames - 24 fields, and the other half three times, 12 frames - 36 fields, making a total of 60 fields or 30
television frames. With the high-speed continuous action of the electron scanning beam this process gives results
that are as smooth as could be desired.
Disregarding for the moment the postwar use of television by amateurs
let us consider its probable commercial form. In the very nature of. things television programming will have to be
far different from the practices which have grown up in the broadcasting industry. Ordinary broadcasting has come
to be, in many homes, a normal background accompaniment to all household activities the day-long parade of soap
operas, shopping advice, and the like, constituting a gentle obligato to the song of the vacuum cleaner. Such
cannot be the case with television. Once admitted to the home this new medium will prove far more exacting -
demanding as it does, our complete and undivided attention. Unless the housewife can develop eyes in the back of
her head and a dual personality she will certainly be unable to peel the potatoes, mind the baby, and do the
week's washing while raptly listening to and watching the adventures of "somebody's other wife."
pioneers in this new industry are well aware of these difficulties in program planning and are prepared to take
appropriate action. It is very doubtful if continuous programs of the type now offered by standard broadcasting
will be available, certainly not until a real demand arises. For the immediate future it appears that television
broadcasting will take place during two well-defined periods of the day, a few hours in the afternoon devoted
mainly to educational subjects, perhaps actually presented in cooperation with local school or college classes,
and an evening program of entertainment running from 7 to 11 or 12 P.M. The costs of television programming are
much higher than comparable sound broadcasts and this factor, combined with the inability of the TVL to sit still
and look for more than a few hours at a time, seems reason enough to expect that our postwar television programs
will be furnished only at those times when a comparatively large audience may be reasonably expected. In the event
that this prediction turns out to be all wrong and we find that the "viewies" run night and day without even time
out to polish our glasses we will have to admit that we grossly underestimated both the commercial possibilities
of this new art and the ability of the American public to "take it."
Now for the amateur possibilities.
During our visit to WABD we met Chief Engineer
S. R. Patremio, W2ITL, to whom we are indebted for taking time out in an extremely busy evening to describe the
various circuits and explain their operation. We also met Howard Schubert, W2JUO, in master control; Melvin Stagg,
W2CNO, and Otis Freeman, W4HGN, video engineers, and Richard Adler, W2NPB, sound engineer. In addition to the hams
just mentioned, the following are members of the Dumont staff: W1ISI, W2AHU, W2EBU, W2ENY, W2GZA, W2HOD, W2HRZ,
W2KCN, W2LNT, W2LT, W2LMA, W2LYS, W2MOH, W2NYY, W20MI, vV8TNC, ex-1RJ, ex-1SS/1RI, ex-W2HEI, ex-2XC/2XD, ex-W6CRM,
and exW9KHG. A similar group probably can be found at other television stations. Knowing the proclivities of
amateurs who work in broadcast stations to take a busman's holiday and sit up half the night pounding brass or
yelling into a mike after having done a full day's work at practically the same thing, we think it highly probable
that. the operators of television stations will likewise go in for ham television .
It now appears that
postwar amateur bands will include not only our traditional long-distance frequencies but will have in addition
lots of room on the ultrahighs - what better use can we make of these frequencies than to plunge wholeheartedly
into experimentation and research in this newest of communication mediums. Who can tell - the day may soon come
when CUL will mean exactly what it says.
1 Hull, "Television, What About It?" QST, November, 1931, p. 20.
2 Lamb, "Radio
Amateurs in the Television Picture," QST, December, 1937, p. 8.
3 Southwell .."The Iconoscope," QST, July,
1944. p, 26.