February 1932 Radio-Craft
Wax nostalgic about and learn from the history of early electronics.
See articles from Radio-Craft,
published 1929 - 1953. All copyrights are hereby acknowledged.
The geographic center of the 48 contiguous
states in America is located about 2.6 miles northwest of the center
of Lebanon, Kansas (39° 50' N,
98° 35' W). That is about
85 miles from the FCC's (Federal Communication
Commission) first central frequency monitoring station at
Grand Island, Nebraska. I have driven by that spot a couple
times while traveling on Interstate 80. Grand Island is probably
not much bigger today than it was in 1932 when
story was published in Radio-Craft, although it boasts being the
state's 4th largest city (population 48,000).
"Island" must have a different definition in Nebraska than in the
rest of the world ;-) Because of its remoteness - 6 miles
from town to minimize electrical noise - a diesel generator
(chosen to eliminate ignition noise)
was installed on-site to provide the necessary 3-phase, 240-volt
power for equipment. Great care was taken to shield cables and motors
and eliminate unnecessary metal structural components. Engineers
who designed and operated this and other early monitoring stations
had no previous data to reference. They were creating the standards
and technical foundations on which future generations would build.
There were no answers in the back of the book to look at if a problem
was too hard to solve, figuratively speaking.
Grand Island Monitor Station
Since the advent of Radio, there has been an increasing need
for some system of accurately checking the frequency of transmitted
radio waves. Before the general use of crystal-controlled transmitters,
calibrated wave-meters served their purpose very well. However,
in order to have any regulation of radio transmitters it is absolutely
essential that the methods of measuring used by the regulating agency
be far more accurate than any method used by the stations involved.
Fig. A - The main. building garage and engine room, 'plane
beacon, and antenna system at the U. S. Monitor Station,
Grand Island, Nebraska.
The discovery of the great value of high frequencies in radio
made the problem of frequency measuring an international, as well
as a national one.
Several years ago, Mr. S. W. Edwards, then Supervisor of Radio
at Detroit, Michigan, foresaw the value of a centrally located monitoring
station, supplemented by several strategically located secondary
standards, and bent his efforts toward securing such a system for
the Radio Division of the Department of Commerce.
The appropriation of approximately $400,000 for land and buildings
having been secured, the next problem was to draw up a primary standard
and associated equipment, and eight secondary standards and their
It was then found that few companies were able to build measuring
equipment of the required accuracy and receivers of the necessary
sensitivity and selectivity. The award was finally made to the Westinghouse
Electric & Manufacturing Company and a great deal of the equipment
now used has been manufactured by them.
Location of Station
With the manufacture of equipment well under way, the next move
was to secure a location for the central frequency monitoring station.
An extensive field strength survey was made of the middle-west,
and finally Nebraska was chosen as the most likely state in which
to locate the station. Several factors prompted the choosing of
Grand Island as a location. Chief among these was, first, it is
centrally located in the United States; second, the level nature
of the terrain makes for receiving conditions approaching the ideal;
and third, the action of the Grand Island Chamber of Commerce in
selling the government fifty acres of land for one dollar.
Fig. B - One-half of the main instrument room of Uncle
Sam's "air police." Every point of the compass is under
inspection, at will.
The exact location of the station is six miles west of Grand
Island. It was deemed necessary that the station should be several
miles from any center of population, in order to get away from "man-made
static." Considerable care was necessary in planning the station
itself. As it is an isolated plant, it must be equipped with a good
water supply, power supply, and heating and sewage-disposal systems.
In order to satisfactorily accomplish the work required of the station,
it was also necessary to build an extensive antenna system.
A visitor cannot help but be somewhat impressed by the amount
of detail that has gone into the construction of this Frequency
Monitoring Station, and can readily see that to properly man all
of this highly scientific equipment calls for a personnel of great
ability who are well trained in their particular phase of the work.
At present, there are 27 people employed at the station. In addition
to the Manager (Mr. Benjamin Wolf) and Assistant Manager there are
eight engineers, all of whom hold B.S. degrees in electrical engineering
or have had wide radio experience, eight radio operators loaned
the Radio Division by the Airways Division of the Department of
Commerce, four Diesel engineers, one chief clerk, two stenographers
and two janitors. This is enough to operate the station 16 hours
a day. It is hoped that funds will be available Inter to add enough
personnel to operate 24 hours a day.
It was mentioned in the first part of this article that in planning
the station, the design engineer was confronted with the usual problems
of an isolated plant, many of which were outside the radio field.
Among these were the buildings, heating and sewage-disposal systems,
and primary power supply. In this work, the help of the Bureau of
Yards and Docks of the Navy Department was sought and obtained.
The architect was F. W. Southworth of the Navy Department.
Fig. C - The other half of the main instrument room of
the U.S. Government's broadcast station frequency monitor
system at Grand Island.
Buildings and Power Supply
There are two buildings, a main building shown in Fig. A, and
a combination engine room and garage. The main building houses the
radio equipment and heating plant. It is built of red brick and
in the shape of a cross. The main floor has a motor-generator room,
a battery room, workshop, main instrument room which is 72 x 35
feet, an office and a kitchen. The second floor has a dormitory
and small office and the basement has a storeroom and boiler room.
The kitchen and dormitory are for emergency purposes in case the
personnel are storm bound.
The other building is built also of red brick and is divided into
a four-car garage, a work shop, and engine room.
The primary power supply is two 40-H.P. Diesel engines driving
240-volt, 60-cycle 3-phase alternators. Diesel engines were used
in order to eliminate ignition interference. The engines are Fairbanks-Morse
3-cylinder, 2-cycle Marine type. Two 2000-gallon fuel oil tanks,
buried outside the engine room, furnish fuel oil for both the Diesel
engines and the oil burning furnace in the main building. The power
from the alternators is made available in the main building through
underground lines to a distributing panel in the motor-generator
room. Motor-generator sets and rectifier units provide the necessary
D.C. for battery charging. The standards and receivers, shown in
Figs. B and C, are all operated from battery supply.
In the engine room beside the engines and their associated equipment,
is a motor-driven pump which is capable of delivering 125 gallons
of water per minute. The capacity of the well itself is in excess
of 500 gallons a minute. This well is used to furnish the general
water supply as well as an irrigation supply for seven acres of
ground surrounding the buildings. This acreage has been landscaped
and in a few years should be one of the beauty spots of Nebraska.
The Stars and Stripes floating from a seventy-foot flag pole in
front of the main building advertises the fact that this is a Federal
Fig. 1 - Grand Island, Nebraska, the most desirable spot
in the United States for the reception of all our broadcast
The numerous fifty-foot poles and the antenna network supported
by them have been recognized as a definite hazard to aircraft. For
this reason, a sixty-foot tower with a 2-million candle power revolving
red beacon mounted on top, has been erected on the grounds. A white
course-light pointing directly to the local airport is mounted just
below the red beacon.
Every effort has been made in constructing the station to eliminate
inductive interference. All motors used at the station are of the
induction type. All power leads are shielded. Copper mesh is incorporated
within the walls, ceiling and floor of the motor-generator room.
All outside power leads are underground. The telephone cable enters
the station through nearly 3/4-mile of underground duct. This is
a 26-wire cable and furnishes ample facilities for local and long-distance
The Sequence of Measuring Station Frequencies
Each measurement goes through four operations before it is turned
in to the office. First, the station must be intercepted and identified
by the receiving operator; second, the measuring sheet goes to the
measuring booth where the station is measured and the sheet stamped
in order of its submittal; third, the final results must be calculated;
and fourth, the entire sheet is checked.
General view of the battery room of the U. S. Monitor
Station at Grand Island, Nebraska. The room is well ventilated
in order to allow the fumes that are generated, to escape.
All the sheets from one day's watch are turned in to the office
the following morning and made up into a report sheet, which is
sent in to the Radio Division at Washington.
Already the needs of the plant have outgrown its present size.
Many more directional antennas are needed if the station is to give
the same service to all parts of the country. This necessarily means
more land, more receiving equipment and more personnel. A high power
short-wave transmitter is needed for more rapid reporting of frequency
deviations. The station must grow and change as the radio art grows
and changes. With proper support, the future of the station is bright.
Uses of the Station
Distributing panel in one of the generator rooms at Grand
Island. The generators used for charging the batteries are
shown to the right of the picture.
The station is designed primarily for the purpose of checking
the transmitting frequencies of all the broadcast stations in the
United States, as well as a considerable number of foreign broadcasters.
Aside from its routine task, Grand Island performs numerous other
special services for the Government. It is prepared, for example,
to report on radio transmission in practically any country on the
Station wavelengths are measured against the Standard Precision
Clock which is mounted in a vacuum chamber in a ten-ton concrete
column. The Precision Clock corresponds to the standard pound, tile
standard foot, the standard quart, etc., in Washington, and is law
to the broadcasters. Its pendulum makes one complete swing in two
seconds, or covers one-half cycle in one second. This frequency
is multiplied through a tuning fork and vacuum tube amplifiers to
30,000 cycles per second, from which harmonics are produced and
selected to match the lowest or highest radio frequencies in commercial
While reception is taking place careful notes are made of weather
conditions, barometrical pressure, and other items which tend to
furnish information on transmitting conditions. Approximate signal
strengths are noted as well as any other characteristics of the
received signal. By reason of this information, it is expected that
transmitting conditions under given circumstances will be predictable,
and that it will be known, in a general way, what stations can be
re-received under certain conditions and at what times reception
will be at its best.
In the second part of this article, which will appear in the
March issue of Radio-Craft, the antenna system and all other available
information concerning this interesting station will be given.
Posted February 4, 2015