SEEN BEHIND THE SCENES OF TELEVISION AT NBC-In the four main phases of
television shown here you see: (a) The studio in the RCA Building where
actors and technicians work under studio lights (b) The master control
room where engineers and directors monitor the sight and sound pickups,
whence the electronic impulses speed by cable to the Empire State
transmitter (c) Antenna atop the Empire State Building which broadcasts
television programs over a 50-mile radius (d) Combination receiver which
reproduces sight and sound transmitted by video and audio carrier waves.
TELEVISION. . . THEN-AND NOW An Adventure in Science
Television began in the minds of men centuries before it became
practical. The longing to see afar, to penetrate fog and night, earth and
substance with our sense of sight is a primitive instinct.
But the specific inventions and discoveries that relate directly to
television go back only to the year
1817 when Baron Jons Jacob Berzelius, a Swedish pharmacist, discovered
a strange element which he named selenium. A scientific oddity of that
day, relatively little was heard of it until 56 years later, in 1873, when
May, a telegrapher working at the Valentia
TransAtlantic Cable Station, in Southwestern Ireland, observed that a
resistor made of selenium transmitted current better when
the sun shone upon it. Other experimenters corroborated the fact that
light causes selenium to transmit electricity better than when it is
immersed in darkness.
This discovery foreshadowed the modern photoelectric cell, a device
designed to convert light variations into equivalent electrical impulses;
this photo-cell principle is the crux of RCA's
all-electronic system of television.
Although we ordinarily think of television as a 20th century
development, its basic principles were known and demonstrated in the
1880's! Silhouettes and crude outlines were televised, transmitted over
wires for short distances, and finally reproduced. Of course, the images
did not compare with the 441-line standard of today.
For several decades thereafter, television was rather dormant. People
generally regarded it as an interesting laboratory oddity, but doubted
whether it could ever be perfected.
One factor which seriously hindered early progress was the lack of a
satisfactory medium for transmitting a program from the camera to the
receiver. But in the period of the World War, 1914-1918, radio developed a
new stride. Spurred by necessity, engineers greatly improved transmitting
and receiving equipment and studied the peculiar nature of radio waves.
Within a few brief years, radio entered the home, and the old crystal sets
gave way to modern vacuum tube receivers. In the pioneer days of sound
broadcasting, it was discovered that crude action pictures could be sent
through the air on radio waves. At once, sensing the practical
potentialities, experimenters attacked the television problem anew. NBC's
parent company, the Radio Corporation of America, was among the first to
enter this field.
A photoelectric cell made possible the first practical tests in
television. The simplest of these tests
(Upper) Television image picture as it appears on the home receiver in
441 lines. (Lower) Natural photograph of the young woman appearing on the
employed a single photo-cell unit. The experimenters soon progressed to
a unit containing eight photoelectric cells.
The television subject stood before this battery of eagle eyes while a
scanning machine swept a brilliant point of light across his face in a
series of parallel lines. In far less time than it takes to tell, the
light was reflected from the subject's face to the photo-cells, which
converted it into pulsating electric currents. Conducted to a transmitter
station, the weak currents were amplified, superimposed upon a radio
carrier wave and broadcast -all similar to the procedure in sound
The receiving equipment used in those early tests was rather crude.
With the aid of a neon tube and a scanning disc, a radio signal was
converted into visible light, thus reproducing the original studio
action in a series of horizontal lines. The televiewers observed the
program through a magnifying glass.
Scanning is the crux of television, and as important to the modern
electronic system as it was to the early mechanical system. The original
mechanical scanning projector used by Dr. E. F. Alexanderson, of the
General Electric Company, Schenectady, about 1930, may now be seen in
NBC's Radio City studios. The experimenter dimmed
(Upper) lconoscope, or "electric eye", of the television
camera. The image is focused on a photo-sensitive mosaic inside the large
end of the tube. (Lower) The inescope, corresponding to the "loud
speaker of an ordinary mdio receiver, transforms electrical impulses into
visible images. The large end of the tube is the fluorescent glass screen.
the overhead light and turned on a
"scanner" which projected a tiny spot of light upon a screen
about 10 feet away. As the scanning disc rotated on its axis you saw the
spot traveling from left to right in a series of parallel arc lines. These
lines - actually composed of spots - were reflected back to the electric
eyes, which created what engineers call the "television signal,"
subsequently amplified and broadcast.
Until a few years ago, the scanning function in the camera and receiver
was accomplished mechanically. Then Dr. Vladimir Zworykin, now a scientist
of the Radio Corporation of America, perfected his system of electronic
scanning, which revolutionized television and ushered in the present era.
The Iconoscope, the television camera's eagle eye, corresponds to the
microphone in sound broadcasting. It is a vacuum tube with a
light-sensitive plate behind the
camera lens. This mosaic plate consists of about 400,000 microscopic
photo-electric cells. The camera lens focuses a given scene upon it, and
an electron gun beam scans the scene as a searchlight would scan it,
moving from left to right and top to bottom, covering the 4 to S-inch
plate in about one-thirtieth of a second. The weak television
"signal" thus created is subsequently amplified and broadcast on
a radio carrier wave.
The image-reproducing tube of the receiver consists of two main parts,
an electron gun and a fluorescent glass screen. After a suitable antenna
intercepts the television
'The television director has stopped a rehearsal to give a few pointers
to his cast.
"signal," it speeds to the electron gun which scans the
fluorescent screen in horizontal lines, and the picture reappears before
your eyes, a faithful reproduction of what originally appeared on the
The electronic system of television appears effectively to solve the
problem of seeing at a distance. Progress in the past five years has been
unprecedented, and it was climaxed in 1936 by the inauguration of an
experimental program service from NBC studios in Radio City. In the months
to come, NBC contemplates carrying this work to a stage of development
that will warrant a daily program service.
A television receiver bears strong resemblance to the ordinary home
radio console, but it really consists of two receivers inside one cabinet
- one receiver capable of reproducing the sound, and the other capable of
reproducing the pictures. The heart of the instrument is the Kinescope,
the large end of which comprises a glass screen on which pictures appear.
The image is reflected onto a mirror under the lid because it is
impracticable to build a receiver with a direct-view
Electrons move at such an inconceivable velocity that in describing the
complex synchronization of the television system, we may think of seconds
as weeks because so many fractional divisions are necessary. The camera
electrons and the home receiver electrons move in a sort of
"lockstep," and if one group lags behind the other by as much as
onemillionth of a second, the finished picture may look fuzzy or
distorted. In a typical television studio, incandescent lights illuminate
a scene and the camera focuses on that scene from
behind the lights. A microphone attached to a "boom" is
suspended above the camera's field of vision. In ordinary practice the
light is diffused evenly throughout the studio. Spotlights may be used to
emphasize certain parts of a scene or close-ups of actors. The purpose of
an aluminum wall surface is to help the eyes make a normal adjustment when
they turn suddenly from a bright scene to an unlighted surface.
The men whose heads, hearts, and hands strive to build an American
Television industry may be grouped into three departments based on their
respective functions, to wit:
Under artificial sun, the program staff creates the form and substance
of television entertainment. All the color and pageantry of modern life,
from a football game to the inauguration of a President, from a telescopic
view of the moon to a microscopic view of microbes, will eventually appear
upon the televiSIon screen.
Nourished by hard toil, a new stagecraft evolves into an art based upon
pre-existing arts, but differing from them all in presenting a wondrous
imagery that conserves time and compresses space within the orbits of your
Had he lived to witness television, Shakespeare might have
said, "All the universe is a stage . . ." From the bowels of
the earth and the depths of the sea to the far, far dominions of cosmic
space there exist no boundaries for human sight. Television program men
hope to bring this universe of life and substance, of fate and
circumstance, before your eyes. What things to see! What riddles to solve!
But before they embark upon such quests, they must familiarize themselves
with numberless details about this difficult technique of broadcasting
animated pictures. Right now they work with simple program material -
one-act plays, travelogues, newsreels, vaudeville, demonstrations of
science, etc. But each day they extend their horizons and draw plans to
embrace new activities.
The chief aims of programming at present are to discover or create
material suited to television, and to learn the best ways of presenting
this material before a television audience. Thus they come face to face
with the grim realities of producing programs that are entertaining and
stimulating, but also different from the usual fare of sound radio, the
stage, and the movies. To find the right solutions they need time.
As with the theatre and the movies, most programs begin with a writer
whose job is to conceive plays and special features, invent plots, draw
characters, plan action, or write dialoguc. His is the creative force, the
chief inspiration and mainspring of human action. Upon completion, the
writer's script goes to the production director who confers with his
colleagues on the problem of translating the cold words on paper into
living human activity. On the basis of their discussions, assignments are
A director is named to supervise production. His responsibility extends
to a .thousand and one details, but he must not overlook that all his
activity is a means to an endto provide provocative entertainment or
graphic information for the televiewer.
In the case of a studio production, the director hands a copy of the
script to the scenic artist who conceives a logical setting for the
action. He sketches a studio scene in rough outline and, following
approval by the director, executes his designs. Artists arrive for
conferences, auditions, and tryouts. Exercising his judgment of their
qualifications and of the specific requirements, the director chooses a
If special sight or sound effects are necessary, they are either built
to order, or selected from a warehouse collection. Costumes and props may
have to be rented.
Rehearsals begin on schedule, and after a preliminary reading of lines,
the three partners of technical production are called in. They are the
camera operator, the sound boom engineer, and the lighting expert.
At present NBC employs several studio cameras, each
"shooting" the action from a different angle. Camera operators
are skilled in the "framing" of pictures and quick to respond to
a director's orders.
The light technician is more than an ordinary stage electrician, for he
must not only understand the color values in corresponding shades of gray,
but he must also know how to "paint" a picture in lights and
The man at the "boom" is charged with picking up both voices
and incidental sound effects in a program. He must, of course, keep his
microphone clear of the cameras' field of vision and at the same time he
must keep it near the actors.
He moves his microphone backward and forward by means of a crank, and
swings it from side to side on a swivel.
Television engineering embraces a wide assortment of outdoor and indoor
activities. The program personnel is responsible for creating a picture
that can be televised. The engineering personnel is responsible for
converting that picture into a suitable "signal" ; also for
transmitting that signal to a transmitter, and finally launching the
signal on a carrier wave that radiates into space.
To control the intricate machinery that makes sight broadcasting
possible, it is necessary to place engineers at strategic points along the
route of a television signal between the camera and transmitter.
In the master control-room overlooking the studio, members of a
"jury" manipulate ingenious devices which enable them to control
the quality of the sight and sound transmitted by the system. Side by side
sit the video control engineer, sound control engineer, and the engineer
responsible for switching from one camera to another.
After a television program is "monitored," it goes from the
RCA building via coaxial cable or "link" radio
transmitter to the Empire State building where sight and sound
transmitters are located on the 85th floor. Here the sight
"signal" is amplified and conditioned for broadcasting on a
carrier wave to televiewers in the New York metropolitan area.
Besides these indoor activities, a squad of engineers is at present ex
Inside the television studio control room. From
this position, the sight and sound engineers and the production director
"monitor" a program as it goes on the air.
Television receiver in a home setting. The image
is reflected from the Kinescope On a mirror under the lid.
Actual scene from "Nine Loves of
Emily", a one-act play, as it was enacted before the electronic
cameras at NBC's television studio.
perimenting with a Telemobile Unit - a complete sight and sound
broadcasting station on wheels for outdoor program pickups.
Supporting all this activity is a group of research men assigned to a
wide assortment of technical problems that bear directly on television
The immediate promise of television broadcasting is for metropolitan
communities, because it is both uneconomical and impracticable at present
to make sight broadcasting as general as sound broadcasting.
Hence, the possibility of a television network as extensive as
present-day sound networks is remote. The comparatively small coverage of
a television transmitter and the high cost of transmitting programs from
city to city preclude any mushroom growth for coast-to-coast networks.
Regional networks, uniting a group of favorably-located cities, appear
more feasible and may materialize within several years.
The practical difficulties confronting television may be judged from
the fact that it would require 100 transmitters to
cover five per cent of the country. It seems, therefore, that for many
years the less populous areas of the United States must depend solely upon
sound broadcasts for radio entertainment. Much remains to be done and no
one can predict when the goal of television will be
reached, but all the experience gained from operating the system on an
experimental basis rather definitely points the way toward a
high-definition daily broadcast service.
Television broadcasting has never earned for itself one cent of
revenue, either in this country or abroad, but those who have faith in the
medium hope that a way may be found to balance the
industry's broadcasting economics. No one expects that television will
yield at profit for years to come from commercial broadcasting. It is a
gradual development requiring wide support from other industries before it
can stand on its own feet.
Preliminary to balancing television's economics, it is necessary to
carryon surveys alluding to population distribution, geographical markets,
network areas, local coverage, etc., involving the preparation of maps,
charts, and tables of figures. Special interviewers, statisticians, and
mathematicians handle this work. Their aim is to establish an economic
stability that will pave the way for a daily broadcasting service with
programs of artistic merit.
The first telemobile unit in
America, built by the RCA laboratories for the use of NBC. NBC's telemobile
unit camera operator places a "sombrero" over the eagle eye of
his camera as he "shoots" toward the sun.
THE QUESTION IS:
The ten questions listed here are asked most frequently by visitors
to NBC's Radio City studios.
Question 1: When will the first scheduled television
broadcasting service begin in N ew York?
ANSWER: NBC plans to inaugurate a regular service in connection
with the opening of the New York World's Fair, in the Spring of 1939. By
that time a limited number of receivers will be in the hands of the
Question 2: How much will a television receiver cost?
ANSWER: It appears that the price will be above that of sound
radios, but the prospective purchaser should remember that he is buying
both sound and sight receivers in one cabinet. Depending upon the size of
the image and numerous other factors, the price of home receivers will
probably range between $100 and $1000. It would seem unwise to purchase a
cheap receiver whose low price makes it impossible for a manufacturer to
incorporate the best materials and workmanship.
Question 3: How far can television programs be broadcast? this single transmitter is
approximately 8000 square miles.
ANSWER: At present NBC's experimental programs, broadcast from the
Empire State tower, are received dependably within a radius of 50 miles.
The coverage of
Question 4: Do you have television in colors?
ANSWER: Inventors in various parts of the world have announced
successful production of television in color. However, it will not be
general for years.
Question 5: What kind of makeup do you use in television?
ANSWER: Makeup has changed constantly since the inception of
television. About 1930 television actors painted their faces white and
their lips black, but the present-day makeup is very similar to that used
in the movies.
Question 6: What will be television's effect on motion
ANSWER: Certain types of motion pictures will fill an important
function in television programs; and this should expand, rather than
limit, the film market. Partly because people enjoy the mass psychology of
a theater audience, and partly because the broadcasting of full-length
features is limited, television offers little competition to the cinema.
Question 7: Is England ahead of the United States in
television development? other nation; in
fact, American patents are vital to European systems. Abroad, it is
customary to levy taxes upon radio audiences, which eliminates sponsorship
that supports radio in America.
ANSWER: In London there is one station which broadcasts daily
programs. It covers all of Greater London, and so Britain's problem is
vastly simplified. Technically, America's standing in television
development equals that of any
Question 8: Why are such bright lights necessary? camera is not
yet as sensitive to light and shade as our eyes. The intensity of
illumination is slightly in excess of that used in motion picture studios,
but research now under way points to a considerable reduction in the
amount of illumination needed for studio operations.
ANSWER: Because the television
Question 9: Will television ruin the legitimate theater?
ANSWER: Indications are to the contrary. Television will certainly
borrow acting talent from the legitimate theater, and the appearance of
these entertainers over television should also promote their stage
Question 10: Who invented television?
ANSWER: There is no single inventor of television, which has been a
dream of many people for more than half a century. The most successful
early experimenters include Paul Nipkow who invented the scanning disc in
1884 and Boris Rosing, active with cathode rays in 1911. Marconi's radio
experiments in the early 1900's were also vital. Zworykin, Baird,
Farnsworth and a score of other experimenters have all contributed to the
present status of television.
Inside the telemobile unit, the engineer in charge manipulates the
SIGNIFICANT DATES FROM THE DIARY OF TELEVISION
1676 - Olaus Roemer discovered that light travels at finite velocity.
1817 - Berzelius discovered selenium.
1830 - Joseph N. Niepce and Louis Daguerre produced the first practical
system of photography.
1845 - Faraday found that a ray of light polarized in a certain plane
can be diverted by action of a magnet.
1857 - Geissler produced the first glass vacuum tube.
1873 - Light-sensitive properties of selenium discovered by a telegraph
operator named May, indicating that light values could be converted into
equivalent electrical values.
1878 - Sir William Crooks invented the Crooks tube, and demonstrated
1883 - Edison discovered the "Edison effect," occurring in an
incandescent lamp. An electric current was made to pass
through space from a burning filament to an adjacent metallic plate.
1884 - Paul Nipkow patented the television scanning disc.
1888 - Photoelectric cells were built.
1890 - C. Francis Jenkins began experimenting with apparatus that could
be used with the Nipkow scanning disc.
1895 - Louste, inventor, demonstrated sound movies.
1906 - Lee de Forest invented the three-element vacuum tube with a
filament, plate, and grid.
1925 - C. F. Jenkins in Washington, D. c., demonstrated apparatus which
showed far-off, moving objects, or "shadowgraphs."
1926 - J. L. Baird, in England, demonstrated television transmission by
wireless and wire by sending half-tone moving pictures from point to
1928 - First television drama, "The Queen's Messenger,"
broadcast from WGY's studios, Schenectady.
1929 - Vladimir Zworykin, of RCA, demonstrated a non-mechanical
receiver using a special cathode ray tube called "Kinescope."
1930 - First showing of television in a theatre. The program was
broadcast from the General Electric Laboratories to Proctor's Theatre,
1933 - After 10 years of work Zworykin announced success of his
"Iconoscope," the modern television camera tube.
1934 - New television camera tube demonstrated by P. T. Farnsworth, in
1935 - New type of wire line, the coaxial cable, capable of
transmitting television signals, announced by Bell Telephone Laboratories.
1936 - July 7th, RCA held a demonstration of the modern 441line
television all-electronic system before radio manufacturers.
1938 - September 15th, NBC conducted first
television sidewalk interviews with passers-by in the Rockefeller Plaza,
New York City. Transmission picked up by NBCRCA mobile television unit,
relayed to Empire State Building and then broadcast to the metropolitan
THE NBC TELEVISION TOUR
A more complete demonstration of the tele-picture art and science is
afforded by the Television Tour at NBC's Headquarters, Radio City, New
York. These paid tours are conducted by competent guides at ten-minute
intervals between 9 A.M. and 11 P.M. daily.
A television broadcast of 1939 automobile models
featured the opening of the New York Automobile Show.
Television image picture of auto company
officials and One of the models paraded before the television camera.