April 1932 Radio News
Wax nostalgic about and learn from the history of early
electronics. See articles from
Radio & Television News, published 1919-1959. All copyrights hereby
old-time radio broadcasts
available on the Internet are obviously recorded version of shows made long
ago. However, back in the day those shows were originally performed live in
front of microphones and recorded in a broadcast studio. With a cast of two
or three or even more, the actors would voice their lines with as much talent
and effort as those performing for movies. The crew usually included a group
of people responsible for creating background sound effects like horses running,
car horns tooting, airplanes buzzing by, and dogs barking. All was done real-time
with split-second timing required to pull it off and sound convincing. Radio
audiences were unaware of all the work required as they sat intently listening
to the Adventures of the Lone Ranger and The Shadow. Behind
the scenes were dozens of engineers and technicians tending local radio broadcasting
equipment and all-important telephone landlines used for synchronizing stations
across the country. Being the primary form of long-distance communications connecting
communities, radio stations had in addition to entertainment and advertising
the duty of maintaining a constant vigil for SOS signals that might be transmitted
from ships at sea, airplanes, and even Zeppelins. If received, the U.S. Navy
intervened to determine authenticity and to usurp, if necessary, the airwaves
in order to conduct rescue activities. It was the glory days of radio, before
television entered the scene.
It's a Man's Job Behind That Microphone
Although Seldom Heard of, These Men Make Broadcasts Realistic
Scene in the Sound Effects Studio, where these wide-awake young fellows,
happy in the knowledge that they are adding to your enjoyment of the radio
programs, are busily engaged making the sounds of train and boat whistles,
horses galloping, airplanes buzzing, chains rattling, the bustle of traffic,
etc., to accompany the oral text of a broadcast playlet. Theirs is not an easy
task, as they have to listen-in with headphones for their cues, which must
be followed immediately by the proper sound, made in the proper way upon the
It's a Man's Job.
By Albert Pfaltz
An Interesting Story of the Little-known But Important Jobs at Which
Many Efficient Radio Men Toil in Bringing Broadcasting to Its Present-day Position
of Perfection. It Is Entirely Possible That There Are Numbers of Our Readers
Who Could Qualify, After a Bit of Efficient Study, for Some of These Positions
Which Are Full of Interest and Remunerative.
In the theatre the inspiring cry has always been, "The Show must go on!"
In broadcasting - a show business on an international scale - the same spirit
prevails. And it is the radio engineer and his associates who now manipulate
the intricate networks of the present day, who plan and execute the broadcasting
of world news events, who make possible the maintenance of high quality radio
The casual studio engineer may notice the control room engineer sitting behind
the glass window of his booth busy at the monitoring panel. He may also notice
the announcer's apparatus with its switches and tiny colored lights. His main
interest, of course, is in the program this side of the microphone. If he is
the average radio fan he knows nothing whatever about what happens to the program
between the two physical points - one of them visible to him - of the studio
microphone and the antenna of the broadcast transmitter. What happens to the
sound in that comparatively short and instantaneous travel is not his concern
in the slightest. It is one of those things that he takes for granted.
An Important Work
And yet the safeguarding of a program between those two points is a work
of engineering art as important, in every respect, as that of the artists and
announcers. Scores of trained engineers are constantly on the job, planning,
testing, monitoring. Taken in toto their work may be described as designed to
preserve two things in any given broadcast-fidelity and continuity.
Broadcast programs originate either in a studio or in the field, the latter
being otherwise known as "Nemo" pickups.
The first named type is comparatively simple. For a brief picture of the
engineering methods employed let us look in at 711 Fifth Avenue, in New York,
It is the announcer who actually controls the switching of a program from
the studio, where a broadcast is about to begin or end. Let us assume that the
artists, the announcer and the control room engineer are waiting for the preceding
program to end and receive their cue to begin. The announcer, who is standing
before a row of push-buttons and lights on a little panel, is listening by means
of headphones to the concluding minutes of a program coming from another studio.
At the conclusion he receives a signal which tells him that the other program
has been completed and that his studio now "has the air."
Tending the Land Lines
Have you wondered just how that program from cross country is switched so
quickly and at exactly the right instant to your local station's antenna? Here
are engineer workers who tend the line terminal equipment panels in connecting
the proper stations with the desired program, although they may be separated
by thousands of miles.
Accurately Timed Switching
Our announcer now strikes the familiar four-note chimes and gives the station
identification. These chimes are utilized as switching cues by individual stations
and supplementary networks joining or leaving the chain.
A problem of synchronization arises here as the smaller chains which tap
the basic networks at a distance from New York may take program service from
either the basic Red or Blue networks. If one network program finishes a few
seconds ahead of schedule the announcer for the other network takes control
of both for the time necessary to give the chimes. All personnel - announcers.
control room engineers, etc. - are in possession of essential information concerning
the distribution of a program and either the announcer or the studio engineer
can set up or release the required program channel.
The duties of the studio engineer who monitors the program from the control
room are fairly familiar. It is his job to control sound levels and faithfully
follow his program cues, such as those calling for the fading down of music
behind an announcement or the balancing of microphones.
Each studio has a twenty-four-hour reserve storage-battery supply for use
in case of failure of the commercial power source.
So much for the individual studio set-up - and there are eight such at headquarters
in New York.
Because of the fact that several programs may be on the air simultaneously,
from either studio or Nemo points of origin and that combinations of local transmitters
and networks are continually shifting, it may safely be said that the main control
room at headquarters is the nerve center of operations. Responsibility for the
operation of studios and the distribution of programs is centered here.
Some idea of the complexity of the layout immediately surrounding the main
control room may be obtained from Figures 1 and 2.
Through constant supervision at this point, programs are dispatched to designated
places at proper levels and at definite times. This requires two things - an
interlocking system for transferring the outputs of various studios to one or
more distribution channels and facilities for checking the program at important
Transmitting Room at WEAF
Shown at the control panel is Gerald Gray, in charge of the station, and,
standing, Raymond Guy, radio engineer of the NBC. These men are ill charge
of complete operations and repair of the powerful 50-kilowatt transmitter shown
at center. At the left is the low-powered unit panel, including modulators
and frequency-controlling devices. At the right is the power-control equipment
and a dummy antenna system.
Program Circuits at New York
Figure 1. This schematic diagram shows the NBC program circuits in New York
City, including nine studios and three audition studios, connecting to the
main control room.
At the Control Panel
Fred Hanek seated at the control apparatus at Bellmore. He is looking at
the oscillograph, on which a continuous moving picture of the broadcast's signals
may be observed.
Special Broadcast Switchboard
These panels, connected in circuit, took care of the broadcast of an "Air
Raid" over New York City. Seated at the board are George Milne, division engineer;
Ferdinand Wankel, engineer, and William B. Miller, director of special broadcast
events of the NBC system.
Lonely, But Important
Here is Engineer Dietsch, who has complete control and operation to the
cooling equipment in the pump room of the WEAF transmitter building. If this
equipment failed for only a short period of time, the transmitter would go
off the air and thousands of dollars' worth of tubes and associate apparatus
would be ruined.
A $1,500 Vacuum Tube
Here are the station engineers holding the largest size transmitting tube
and comparing it with the small 199 receiving tube employed in early battery
Control Room of Times Square Studio
You never think of these watchful engineers on duty when you listen to a
program from this famous studio, but they are there with eyes, ears and brains
alert to conquer any emergency that might tend to interfere with the broadcasts.
The control room supervisor has available volume indicators and a loudspeaker,
the former showing output levels of studio and line amplifiers while the latter
may be connected to either of these points. In addition, the signal light shows
whether the local transmitters, WJZ and WEAF, are "on" or "off" the air, and
a neon lamp indicates whether the carrier is being modulated and, roughly, the
degree of modulation. A circuit can be quickly patched around any faulty unit
as the input and output connections of most of the equipment in each studio
appear on jacks in the control-room apparatus.
Furthermore, telephone connections to all monitoring booths and telegraph
circuits to all networks and local transmitters are available to the control-room
Present-day broadcasting depends, very largely for uninterrupted service,
on the efficiency of the network of telephone lines which connect cities, studios
and transmitters. The telephone company is responsible for the maintenance of
program service between network stations. Few persons realize that dozens, and
sometimes hundreds, of wiremen are stationed at strategic points during an important
network program where, because of the single factor of geography, almost any
kind of climatic condition may be encountered - to say nothing of an "act of
God" which might cause a truck loaded with high-explosives to collide with a
However, engineers of the broadcasting company frequently check the transmission
characteristics of all long-line networks. The shorter local lines, which seldom
give trouble, are checked daily and then rechecked immediately prior to a broadcast.
Frequency characteristics are also taken covering the entire circuit from microphone
Before outlining the more intricate problems involved in the handling of
a big news event broadcast, such as the arrival of the air armada over New York
or the initial trip of the Graf Zeppelin, let us consider the transmitter -
the comparatively new WEAF, for example, which is the last step in the engineering
chain required to put a program on the air.
The new 300,000 watt transmitter was installed in a recently constructed
wing of the WEAF operating building at Bellmore, Long Island. O. B. Hanson,
manager of plant operation and engineering, and Raymond Guy, radio engineer,
declare that this apparatus, which embodies the latest ideas of radio transmission,
now makes every sound picked up by the microphone audible to listeners as far
away as New Zealand.
The station operates with a maximum power of 50,000 watts. With the modulation
increased from less than fifty to one hundred percent, listeners receive the
signals several times louder. High and low notes, sibilants and certain sounds,
heretofore heard indistinctly or lost entirely, now are transmitted perfectly.
The equipment includes the latest refinement in crystal-control apparatus to
hold the station on its assigned wavelength, giving increased frequency stability.
Careful observations show that the fluctuation is only ten cycles in 660,000.
The transmitter employs two 100-kilowatt type tubes which stand five feet high
and require thirty gallons of water, per-minute, to cool them.
The central control panel gives the operator an unobstructed view of the
apparatus, while an oscillograph gives a moving picture of the transmitter's
Every possible safeguard is present to insure continuous operation of the
large water-cooled tubes. Tube failure may often endanger surrounding apparatus.
For one thing, the supply of cooling water must be adequately sustained. Furthermore,
operational steps must be taken in the proper order - as, for example, the application
of filament power only when an adequate flow of water is assured and the application
of plate power, after that of grid-bias voltage. An interlocking relay system
functions in the event of failure, or overloading, of any unit, thus disconnecting
service before any serious damage can result.
Tube replacement is handled by a push-button arrangement on the desk of the
transmitter engineer. Duplicate units and rapid replacement facilities are also
provided for other apparatus.
Lightning has long been a great danger to a transmitting station - and still
is - although radio engineers have recently developed certain safeguards. Charges
of lightning which have entered the station on the lead-in have been known to
melt 30-inch condenser plates to molten liquid. Today the modern set-up includes
static drains which consist of a coil and a resistor, across the apparatus from
antenna to ground.
But what happens when an SOS signal is on the air?
Every broadcast transmitter is equipped with a special receiving set, adjusted
for the reception of 600-meter waves, the wavelength assigned by international
agreement, for SOS signals. A big loudspeaker is placed at an advantageous point
so that the transmitter crew can hear any signals that come through. The operators,
who work in eight-hour shifts, are constantly alert to any signals received.
If any signal even remotely suggesting an SOS is heard, the station immediately
telephones the nearest U. S. Navy Yard for advice. If the station operators
are confident of the signal they immediately discontinue broadcasting, otherwise
they await orders from the Navy Yard. Broadcasting is resumed when the Navy
department sends out permission to resume by 600-meter signals.
The ordinary distribution problem involved in a network broadcast is difficult
enough but in point of complexity the Nemo broadcast, often requiring seven
or eight announcers, a corps of engineers and the supplementary use of short
waves, takes the grand prize. Engineers and announcers have often spent days
of preparation and rehearsal in advance of such an occasion.
Before describing some of the interesting engineering hook-ups used on important
news broadcasts, it is necessary to speak of the piece of apparatus, recently
designed, that serves as the nerve center coordinating all activities in the
Technically known as the "semi-portable Nemo switching equipment," the extremely
flexible, compact and efficient apparatus developed and built by the engineers
is a miniature broadcasting studio.
This apparatus, supplied with batteries for use where regular power supply
is unavailable, is contained in a box measuring approximately 2½ x 4
x 7 feet and weighing a half ton. The "box" may be shipped to any desired centralized
point from which wires are radiated to whatever locations participate in the
When completely installed, the equipment is capable of providing ten-way
communication, among as many locations. Ten announcers, within any radius -
even scattered throughout the country - could talk among themselves and also
to the broadcast listeners. This intercommunication is accomplished by means
of special "feedback" amplifiers which permit each point to hear every other
point. Inter-communicating telephone circuits are also provided. Each of these
ten broadcast circuits may be controlled for volume, or switched "on the air,"
separately or simultaneously.
The program director at the central control point can talk to any of the
distant announcers by means of the feedback amplifiers and, unknown to the listening
radio audience, can direct the entire broadcast.
Provision is made for testing a set of circuits while the others are being
used, for broadcast and testing equipment is provided for the rigorous checking
of telephone circuits required in the broadcast field:
It is probable that only a small fraction of the millions of listeners have
the slightest knowledge of the men sweating behind the scenes, in radio. They
listen to a broadcast as a simple, matter of fact and connected narrative, without
realizing that many men have worked for days - or, at the very least, for hours
- to make it possible. That is as it should be.
But it is these "unknown" workers, unseen, unheard and unsung, who have produced
a radio-minded nation which today accepts with utter calmness the voice of Col.
Lindbergh speaking from Tokyo, music from Chicago or an address from Rome.
Control Panel Circuits
Figure 2. Schematic diagram of the actual program circuits to the studios
and to the channels of the control room shown as part of the diagram in Figure
Posted January 20, 2021
(updated from original post on 10/20/2013)