A Detroit Apex Station in 1936
as 1932, the public was becoming dissatisfied with the sound quality
of AM broadcasting. They complained about low fidelity, heterodynes
and squeals, AC hum on some stations and the ever-present static. The
Federal Radio Commission (soon to become the FCC) started
investigating the possibility of “high-fidelity” radio.
two-element crossed dipole antenna was mounted on the decorative ball
that capped the landmark Detroit building. W8XWJ operated with 100
watts on 31,600 kHz.
first step was to expand the upper end of the AM band in 1932,
setting aside three frequencies for experimental wideband
“high-fidelity” stations – 1530, 1550 and 1570 kHz. (One such
station, W2XR in New York City, evolved into today’s WQXR-FM.)
Their second move was to permit experimental high-fidelity
broadcasting on the upper short wave frequencies.
Assistant Chief Engineer Andrew D. Ring called them “Apex”
stations. He said “these ultra high frequency stations must be
located upon a high point, since their signals simulate light and
must ‘rain down’ for good reception.” Because they weren’t
limited to the AM band’s 10 kHz channel bandwidth, the new Apex
stations could transmit wideband high-fidelity AM.
existing AM broadcasters quickly applied for Apex licenses so they
could simulcast their programs in high-fidelity and stake out their
claim for this new broadcast band. The first Apex station was W8XH in
Buffalo, started by WBEN in 1934, and by the end of 1938 there were
more than 50 Apex stations. Among these was W8XWJ operated by the
Detroit News station WWJ, seen in these photos.
began broadcasting on Jan. 29, 1936, on a frequency of 31,600 kHz.
The studio and antenna were on the top floor of the Penobscot
Building, one of Detroit’s tallest buildings. A two-element
turnstile crossed dipole antenna was mounted on the decorative ball
atop the building’s peaked roof. W8XWJ mostly simulcast the regular
photo at left, WWJ Chief Engineer C.H. Wesser is seated at the
station’s speech input panel. The RCA 100-F ultra-shortwave
transmitter is at left. Also visible is an RCA transcription
turntable and an RCA 50A inductor microphone. The transmitters
specified an operating range of 30-41 MHz at 100 watts, with an audio
frequency response of 30 to 14,000 Hz. Western Electric also
produced Apex transmitters for a few years.
stations suffered the same “chicken and egg” problem that
broadcasters have since seen many times with new technologies – a
lack of commercially available receivers. The tuning range of most
all-band radios in the mid-1930s stopped at about 20 MHz, and only a
handful of models tuned the “ultra high frequencies.” Some
stations offered converter boxes to the public that would shift the
tuning range of standard shortwave radios up to the Apex frequencies.
problem was skywave interference between Apex stations. The FCC’s
solution was to create 75 channels from 41.02 to 43.98 MHz, separated
by 40 kHz. The stations used amplitude modulation, but a few asked
for permission to transmit with the experimental and still unproven
Frequency Modulation (FM) method. Major Edwin Armstrong, the
inventor of FM, was among the first to receive authority to transmit
FM from his station W2XMN. The FCC sent its engineers to New Jersey
to investigate, and they were thoroughly impressed by the Armstrong
station’s coverage. They listened to the station 50 miles from the
transmitter site. They also heard W2AG from Yonkers, operating on
110 MHz with 500 Watts. They reported back that FM was clearly
superior to AM.
Engineer C.H. Wesser works the gear.
March and April of 1940, the FCC held a series of hearings about FM.
On May 20, it announced the assignment of thirty-five 200 kHz-wide
channels above 43 MHz for FM. All existing experimental
high-frequency licenses, both AM and FM, would terminate on Jan. 1,
1941, and the FCC encouraged those stations to reapply for new
commercial FM licenses. No AM broadcasting on the ultra-high
frequencies would henceforth be allowed. The remaining Apex stations
began shutting down or converting to FM in droves.
it’s evident that Apex was only a transitional phase in the
development of FM. Nonetheless, perhaps as many as a hundred Apex
stations had existed between 1934 and 1941. From them, broadcasters
learned important technical lessons about VHF transmission and
reception, which was vastly different than medium-wave.
antennas and transmission lines all worked on different principals.
Propagation characteristics of the new “ultra short wave”
frequencies were seriously studied for the first time. There were new
issues with the use of high-fidelity audio. Without these valuable
experiences, the development of the nascent FM broadcasting industry
would certainly have taken much longer.
from the Detroit News Archives.