WEAF - MOVING NBC's FLAGSHIP STATION, 1940
By John F. Schneider, 2020
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WEAF - MOVING NBC's FLAGSHIP STATION, 1940 By John F. Schneider, 2020
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www.theradiohistorian.org Copyright 2020 - John F. Schneider & Associates, LLC (Click on photos to enlarge) A closeup view of the
WEAF transmitter building, showing the spray cooling pond.
The water from this pond was pumped through a
heat exchanger, which in turn cooled the distilled water which
circulated
around the transmitting tubes.
A back view of the property, showing tower #1 and the coaxial line that extended to tower #2, out of view to the right. Construction of one of the WEAF towers at Port Washington. (ATE Journal, August, 1940)
Here is another view of the WEAF transmitter in Port Washington. The power amplifier cabinet is at the far right; the 5,000-watt exciter and intermediate amplifier is in the center; and the cabinets at the far left contain the audio control equipment.  This
is a rear view of the high voltage
rectifier cabinet, showing the six mercury vapor rectifier tubes that
supplied
20,000 volts at 10 amperes to the final tubes.
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Being a technology pioneer is
often a disadvantage. The first
practitioners of a technology learn
both the benefits and shortcomings of the technology, and then those
that
follow have the benefits of those lessons and then overcome them with
improved
solutions. Such was the case for NBC’s
flagship radio broadcasting
station, WEAF in New York City. In 1927, WEAF was one of the first
radio
stations in the country to operate at 50,000 watts – a power level
which today is
still the maximum allowed power for broadcasting on the standard AM
broadcast
band in the U.S. As a condition of
allowing such a previously-prohibited high power, the Federal Radio
Commission
required WEAF to be located far enough outside of the city to avoid
overloading
listeners’ receivers. So it was that the
location chosen for this high-power facility was Bellmore, Long Island
– 25
miles east of Manhattan. The WEAF
installation in Bellmore was cutting-edge technology in its day, but it
quickly
became obsolete as improved transmitter and antenna technologies were
perfected. The original transmitter was
only used for four years before it was replaced by the more modern RCA
50B in
1931. (See WEAF Bellmore Tour). But an improved
transmitter still did not overcome the limitations of the location. By the mid 1930’s, consumer
receivers had improved
greatly. The old TRF (Tuned Radio
Frequency) designs had for the most part been superseded by modern
superheterodyne technology, which offered sharper tuning and better
rejection
of unwanted signals. Additionally, AGC
(Automatic Gain Control) circuits kept strong signals from overloading
the
receivers. Now, even with its 50-kW
transmitter, WEAF was at a disadvantage in New York City, where smaller
stations broadcasting from sites much closer to the city delivered
clearer
signals to their listeners. Being the
station that delivered the nation’s most popular radio programs to its
biggest
city, it was imperative that WEAF move closer to New York. NBC’s decision to change sites was
temporarily delayed when
Cincinnati’s WLW was given permission to broadcast experimentally with
500,000
watts. At first, NBC was optimistic that
WEAF would be given the same permission, and then Bellmore would have
been a
good location for such an installation.
But towards the end of the decade it became clear that the
FCC was not
going to permit super-power broadcasting in this country. (WLW’s
experimental
authority was rescinded in 1939.) Finally,
approval was given to find a new site for WEAF, and Raymond Guy, chief
engineer
of NBC’s radio facilities section, was given the task of finding a new
location.
It would not be easy. Using a 100-watt transmitter, a
mobile test vehicle roamed
the region to locate the areas having the best propagation towards the
metro
area. This narrowed the choices down to
two areas – Milford, New Jersey, and Kings Point, Long Island. Only one suitable property in Milford could
be identified, and it was owned by a farmer who was reluctant to sell. After much haggling, he agreed to give NBC an
option on the property, but for just three months because he needed to
get his
spring crops planted. This was not a
viable amount of time in which to obtain an FCC construction permit,
and so the
search team concentrated instead on Long Island. In
any event, Kings Point would be a better
choice in terms of radio propagation, offering a clear salt-water path
across the
East River entrance to New York City. A
200-acre site was identified and its owner agreed upon a ten-year lease
with an
option to renew. But Kings Point was an
upscale suburban area with strict building codes prohibiting industrial
use. Lengthy negotiations with the city
managers ultimately failed to obtain a waiver of the building code
obstacle. A few miles farther to the east,
the search team discovered
a 102-acre parcel in Port Washington. It
belonged to a defunct sand company and had been auctioned for back
taxes, but
there were no takers. NBC quickly
obtained a six-month option on the property for $1,200 an acre. It was a superior site, also offering a
salt-water path to New York. Although
farther away than Kings Point, it was ten miles closer to Manhattan
than
Bellmore. The next obstacle was to obtain
clearance from the CAA (Civil
Aviation Authority – the predecessor to today’s FAA). A
private seaplane airport located a mile away
from the property objected to the project, afraid that WEAF would
interfere
with airport communications. This turned
into a controversial topic in the community, with arguments both for
and
against appearing in the local newspapers.
In the end, the interference issue was overcome, but the
proposed half-wave
tower height of 740 feet was denied. To
compensate, NBC chose to instead use two 320-foot towers, creating a
slight
directional signal to the west, but this would require more land. This was solved with a complicated trade deal
with an adjoining property owner to acquire an additional ten acres. It was also discovered that the public road
that needed to be extended to reach the site was blocked by a
one-foot-wide
section of property that someone had acquired for the express purpose
of
preventing extension of the roadway. Fortuitously,
they were able to make a deal with that owner to acquire the one-foot
parcel. Finally, with clear title to the
property and approval from
both the CAA and the FCC, construction at Port Washington began in
1939. NBC’s final cost to acquire the 50
acres was
$80,000, possibly highest price ever paid for a broadcast site to that
time. A one-story brick structure with
basement was constructed on
the property. Two quarter-wave
self-supporting towers were erected, located 475 and 875 feet from the
building. Rigid copper coaxial lines
stretched
above ground to the two towers. Two
redundant 10 kHz AT&T broadcast lines were installed to bring
program audio
to Port Washington. routed via separate paths to increase redundancy. It would be necessary to keep
Bellmore on the air while Port
Washington was constructed, so another transmitter was needed. As it happened, NBC’s station WENR in Chicago
had recently combined its operations with WLS.
The two 50 kW stations shared time on the same frequency,
and so one
transmitter was now serving both stations from a single antenna. Because the previous WENR site at Downers
Grove, Illinois, was being decommissioned, the station’s RCA 50B
transmitter
was available to WEAF. The rectifier and
power amplifier of the WENR transmitter were brought to Port
Washington, where
they were joined with the 5-kW driver from Bellmore -- the old site’s
auxiliary
transmitter’s driver was substituted to keep WEAF on the air. All of this equipment to be used in Port
Washington was extensively rebuilt and modernized – the motor-generator
filament and bias power supplies were replaced with rectified AC
supplies, and
several older and obsolete tube types were changed to more modern and
efficient
ones. When the work was done, the
reassembled transmitter was state-of-the-art for 1940, with audio
frequency
response measuring flat from 30 Hz to 16 kHz. Noise was -65 dB, and
distortion
less than 2% at 100% modulation. Finally, the Port Washington site
was turned on November 8,
1940, and the Bellmore site was shut down and retired.
The improvements in WEAF’s signal were impressive
– the signal strength in Manhattan increased from 10 to 75 mV/m. The station was now as strong in the city as
any signal on the dial, and it could be heard clearly at night over
half the
country – a proper signal befitting the
network’s most important station. WEAF operated from the Port
Washington site for the next 23
years. The historic call sign was
retired in 1946, when WEAF became WNBC.
(It was changed again to WRCA in 1954, and then back to
WNBC in
1960. In 1988, Emmis Broadcasting
Corporation
acquired the station and it became WFAN.)
But there was still one more move
in its future. In 1963, NBC and CBS joined
forces to
construct a shared transmitter site on High Island, off shore from the
Bronx. This site was even closer to New
York City and allowed for a taller tower and saltwater ground system. The co-owned project was a success, and both
WCBS and WFAN still broadcast from the island’s single 528-foot tower
today.
This article
originally appeared in the December, 2020, issue of THE SPECTRUM MONITOR REFERENCES:
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