"We are standing on the threshold of the Age of Television!" "Television
will enliven and broaden your life more than you can now appreciate.
It will become part of your daily life just as radio is today."
"The best evidence that the public thinks well of television is
the universal response that comes from those who have a chance to
see it." Broadcast television which will add a new dimension to
home entertainment and will provide one of the most powerful mass
advertising media ever developed." So proclaimed spokesmen for Dumont,
Farnsworth, Philco, and General Electric, respectively, in 1945.
GE clearly had its future pegged on the real revenue potential of
any mass media: advertising dollars. I wrote recently of the near
doubling of time allocated to each broadcast hour for commercials
today compared to the in the 1960s. Companies will pay $4 million
for a 30-second spot for
Super Bowl XLIX this year.
An Introduction to Television
By Edward M. Noll
The first of a series of articles to be presented to the serviceman
on the subject of television, covering operational principles and
Method of relaying television programs
from station WNBT, New York City, to General Electric's station
in the Helderbergs and from there to the Capital district. GE's
studio, WRGB, at Schenectady, also relays programs to the main transmitter.
Are you prepared for television? Are you prepared to guide the
television bandwagon when the television beam sweeps across the
screens of a million television receivers? Manufacturers predict
every major marketing area will be served with stations within a
year after peace. Surveys of public opinion indicate extraordinary
interest in television. You, Sgt. or Mr. Radioman, in the immediate
postwar era, will be called upon to service, install, operate, or
teach the principles of television equipment. You have been absorbing
many new circuits and applications of vacuum tubes under the impetus
of war - so why not, while you're in the stride, set aside a few
hours each month to obtain a necessary background in a pioneer industry.
What you learn about television now will not only aid you in your
present activities (practically every radio concept manages to become
involved in television at some point) but is an educational war
bond to be cashed in at a later date.
Personnel with a working knowledge of television will be in demand.
Personnel, not only to staff the production plants and the big stations
but personnel to sell, adjust, and service receivers. The television
receiver, in its present state, is critical of installation and
adjustment. You can not throw a piece of antenna wire out the window,
plug into the wall socket, turn the switch and expect to get a presentable
picture. Your television receiver, no matter how well it is engineered,
is useless without careful installation, a good antenna, and proper
adjustment. You, Mr. Serviceman, must be able to do your part. The
customer will not pay cash-over-the-counter for his receiver, pick
it up and take it home. Final payment will be made when the receiver
is properly installed and receiving a satisfactory picture. The
television serviceman will have to bring out his glasses, light
up his easy-chair pipe, and study a few hours every so often. The
serviceman who knows "why" as well as "how" will be a faster trouble-shooter
than the mechanical robot who knows how to handle a test panel but
doesn't know what he's looking for. All of this demonstrates the
need for trained personnel. Although the purpose of this series,
primarily, is to present the television receiver to the serviceman,
the first few installments will cover the complete system to unveil
television in its entirety.
The four classifications of television stations are commercial,
experimental, remote, and relay stations.
The control room at WBKB. Chicago. The program director,
in the foreground, masterminds the production in the adjoining
studio by means of an intercommunication system connecting
her directly with each of the operating personnel.
1. Commercial stations are of two types: the large regional station
with its high-power and elaborate facilities, and the small local
station, with its limited facilities. The local station nevertheless
will have the same high-quality broadcasts, as it will re-televise
the larger regional station, augmented with the local broadcasts
it can readily handle with its own limited facilities. A wide variety
of programs have been broadcast from the nine licensed commercial
television stations shown in Table I. The Philco station in Philadelphia
has been especially successful in handling sports events - particularly
football. Not only is the picture clear but the operation of the
system is fast enough to follow each play without difficulty. The
General Electric station in Schenectady has obtained gratifying
results in telecasting operas and stage plays. Its elaborate studio
facilities have demonstrated what can be done in the production
of first-rate stage shows. The New York stations broadcast many
live talent shows - from instructions to air-raid wardens over the
NBC station WNBT to the antics of a live duck over CBS station WCBW.
At present there are 70 applications pending before the FCC for
commercial television stations. Many of these applications come
from smaller cities. It is evident, wide television coverage is
not too far off. The average cost of establishing a television station
is approximately $200,000; cost, of course, is dependent on how
elaborate the station is to be. The small town local with a relay
connection to a larger station could begin with only a limited amount
of equipment - perhaps only a small motion picture camera to handle
local advertising and film broadcasts.
2. Remote stations will operate in conjunction with the commercial
stations to handle the remote telecasts. The remote station generates
its own signal at a very-high frequency which is picked-up at the
main station and retelecast on the main transmitter. Remote telecasts
have been very successful for both day and night events.
3. Relay stations permit the transfer of television programs from
city to city bringing high-quality telecasts to the smaller cities
and rural districts. Ordinarily, the small local station will not
have the facilities to present a continuous stream of elaborate
telecasts but will depend on his big city brother to give him additional
talent. There are two successful relay systems on the East Coast.
One is between NBC's New York station and the Philco station in
Philadelphia; the other, between New York again and the General
Electric station in Schenectady. The latter relay system has one
jump of 129 miles which is considerably, beyond normal line-of-sight
Thus it appears that the wise use of directional antennas and
proper choice of site will go a long way in extending the range
of television transmission. General Electric is encouraging the
use of a very low power combination local and relay station which
will receive its energy on a highly directional beam from the larger
station and retelecast it at a higher frequency for local coverage.
The relay and local station will require a minimum of equipment
and will be practically automatic in operation. Facilities will
be available for handling local shows.
4. Experimental stations must be given free rein in conducting
experiments which will advance the television art. All the production
plants and television broadcasters are to be commended in developing
cathode-ray tube television to its present state. Furthermore, under
the impetus of many war disclosures, television should rise to its
Table I. - Tabulation of commercial television stations
that are in operation.
Table II. - Chart showing the possible increase in television
The Columbia Broadcasting System advocates the use of higher
frequencies to obtain greater picture definition, higher frequencies
also being more adaptable for color television. The development
of the art must not be impeded by rash business tactics and premature
technical freezing. Experimental licenses should be granted freely
for development work on the very-high frequencies. The radio amateur
must be given a television channel, along with the educational institution
which will introduce television to the radio jobber, serviceman,
or the young engineer.
One television station is six megacycles wide; the entire broadcast
band, one megacycle wide. The very wide bandwidth is necessary to
transmit a clear and sharp picture. In fact, a picture transmitted
on a still wider channel would be further improved. The Columbia
Broadcasting System is a progressive advocate of higher frequencies
and broader channels, recommending 16-megacycle channels in the
frequency range from 450 to 950 megacycles. At present there are
18 television channels, each 6-megacycles wide, extending from 50
to 294 megacycles. However, only the first four channels, 50 to
84 megacycles, are occupied by commercial stations.
At a recent session of the television panel of the Radio Technical
Planning Board the following frequency recommendations were prepared
for presentation before the Federal Communications Commission.
1. The use of 26 6-mc. commercial channels extending from 50
to 246 megacycles.
2. The use of a number of 12-mc. relay channels from 162 to 294
3. The use of 20 10-mc. relay channels between 300 and 1,000
4. The use of 20 20-mc. relay channels from 1,000 to 3,000 megacycles.
5. The use of 30 20-mc. experimental channels from 600 to 2,000
6. The use of additional allocations for experimental channels
from 3,000 mc. to 10,000 megacycles and higher.
Fig. 1. - Illustrating the progressive series of electrical
charges during a television transmission. Each charge represents
the relative brightness of one tiny spot on the picture
tube. During transmission. the object being telecast is
focused on the mosaic. The image appearing on the mosaic,
after being scanned by a beam from the electron gun, is
applied to the video amplifiers. Synchronizing and blanking
pulses then combine with the picture signal and the composite
video signal is applied to the transmitter and radiated
by the antenna. During the receiving process the television
signal is picked up by the receiving antenna and detected
by the receiver. Picture signal and blanking pulses then
pass through the video amplifiers to the beam-control grid
of picture tube. Synchronizing pulses are applied to the
synchronizing circuit to control operation of electron gun.
Modulated picture beam scans the fluorescent picture-tube
screen. reproducing the original image.
A televised scene is not transmitted instantaneously. It is transmitted
as a progressive series of electrical charges, each charge representing
the relative brightness of one tiny spot on the scene. Approximately
350,000 of these spots are required to mold one scene, and, to simulate
motion in the picture, thirty complete scenes or frames are transmitted
each second. As shown in Fig. 1 the object is focused through a
lens system on the light sensitive screen or mosaic of the television
pickup tube. The image on the mosaic, which is dotted with millions
of tiny photoelectric particles, displaces electrons according to
the light distribution of the image. This image is scanned by a
pinpoint electron beam which races back and forth across the screen
as directed by the electron gun of the pickup tube. When the beam
scans one line on the mosaic a progressive series of very small
charges (video signal) are released. The relative strength of each
individual charge is dependent on the intensity of the light focused
on the particular spot it represents on the mosaic. After one line
is scanned the beam snaps back and scans another line beneath the
previous one. This process continues until 525 lines are covered,
representing one scene or frame. Then the beam returns to the top
of the screen and scans the first line of a new scene. Point-after-point,
line-after-line, and frame-after-frame, the television signal is
transmitted in an endless stream from transmitter to receiver. At
the receiver the same parade of charges excites the control grid
of the picture tube's electron gun. The beam from the picture tube's
electron gun, in step with the motion of the pickup tube beam, scans
a fluorescent screen. However, instead of releasing a charge the
intensity of the beam itself is changed in accordance with the variations
of the received signal. Consequently, the illumination of the screen
is varied point-by-point and line-by-line, reproducing the original
relative light distribution of the image, on the screen of the receiver
Two other types of information transmitted on the television
signal are synchronization and blanking. The synchronization signals
are a series of rectangular pulses which keep the scanning beam
of the television picture tube in step with the scanning beam of
the pickup tube. Consequently, the receiving tube beam is always
directed toward the same relative spot on the fluorescent screen
as the pickup beam is scanning, at the same moment, on the mosaic.
The sync pulses also set the time at which both scanning beams snap
back from left to right and from bottom to top. Since a definite
time interval is required for the beam to snapback or retrace, a
retrace line would ordinarily be visible on the screen. Another
pulse, called a blanking pulse, removes this possibility by shutting
off the beam from the electron gun during the retrace intervals.
Next month's installment discusses in detail the scanning process
and construction of the standard television signal.
Predictions of the vastness of the future television industry,
brought out by some of the major television interests.
James L. Fly Former Chairman, FCC.
"Demobilization day will find television a fully explored but
wholly unexploited field. We can anticipate a widespread demand
for consumer goods such as television sets, many factories able
and ready to convert back from war production to such consumer goods,
and all the other factors necessary for the most rapid postwar period
"I think it quite likely that during the postwar period television
will be one of the first industries arising to serve as a cushion
against unemployment and depression. Radio broadcasting served that
function in a measure during the 1920's, though at the close of
the war wireless was far less developed than television will be
at the close of this war. There is no reason now apparent why we
should not aim at a 50,000,000-set television industry mirroring
the present 50,000,000-set broadcast industry."
"Approximately $25,000,000 has been invested in television research
and development by the radio industry to get television ready for
the public. Probably never before has the product of a great new
industry been so completely planned and so highly developed before
it was offered to the public as has television. Through long years
of research and development, the television art has been so perfected
that the product itself and the service it renders will be ready
for the public in a highly-developed state as soon as the war is
"The best evidence that the public thinks well of television
is the universal response that comes from those who have a chance
to see it. As soon as television receivers can be made and sold,
the public will eagerly buy them in tremendous quantities. It may
be possible to produce and sell table model television receivers
for as little as $125 after the war. Larger 'projection type' sets,
giving a picture 24 inches by 18 inches may cost up to $400."
"As we see it there will be two major applications for television
after the war. The first, and perhaps the most important is broadcast
television which will add a new dimension to home entertainment
and will provide one of the most powerful mass advertising media
ever developed. Secondly, there is industrial television in which
pictures and sound will be carried by wires or by radio transmitters
from one point to another for various private commercial uses. For
example - industrial television might be used as a powerful merchandising
medium by a department store. The fashion show taking place on the
eighth floor might be wired to display projectors located on all
other floors of the store and in the show windows, enabling shoppers
throughout the store to see the latest styles.
"Theater television may well be of the industrial variety. A
live-talent program originated at a central point could be wired
to a number of theaters and then projected on the regular theater
screens. News and sporting events could be made available to the
audiences of a large number of theaters by such a system."
Columbia Broadcasting System
"Almost total military secrecy surrounds the surging story of
electronic progress in the war. But the effect of this progress
on U. S. post-war television - if the television industry will seize
it - is well known to nearly every engineer who has worked, often
around the clock, on the deadly electrons of war.
"Enough has already been done - developed, tested, proved, and
put to work - to strike off the technical shackles that held prewar
television to a relatively coarse-screen picture; enough to free
television from the straitjacket of narrow-band, black-and-white
transmission; enough to promise pictures twice as large and twice
as rich in detail, as well as pictures in full and brilliant color.
Enough, in sum, to make the 'good-enough' pictures of prewar vintage
seem not good enough at all, in terms of postwar possibilities."
"Television will enliven and broaden your life more than you
can now appreciate. It will become part of your daily life just
as radio is today."
"It will be housed in a handsome cabinet, differing from a radio
cabinet only in that it brings you sight as well as sound of distant
events while they are taking place! As with radio, you select and
tune in the programs you want.
"Television is a new service with characteristics and powers
peculiar unto itself. It combines qualities of movies, newspapers,
radio, and stage. Television will bring you entertainment ... Broadway
or Hollywood openings, operas, plays, movies, concerts.
"It will show news being made ... spot news of fires, parades,
politics, disasters, picked up by traveling television cameras ...
commentators who can illustrate maps and places and people.
"And it will bring you advertising, show you the products, how
to use and care for them.
"Television will be your window opening on the world - a magic
window that gives eyes to radio, and will give you a sense of personal
participation in faraway events as they happen."
"We are standing on the threshold of the Age of Television!"
"Soon, imagination and genius, freed of wartime limitations,
will be breathing vibrant life into television's magnificent promise.
"Television did not come to a technical standstill when America
entered the war. When the new science of electronics was drafted
for the creation of secret weapons, the technical progress of television
continued in many specialized ways ... resulting in countless refinements
in high-frequency circuits, in precision methods of manufacture,
and many hush-hush developments of important benefit to television
which may not be discussed at this time."
Posted January 11, 2015