radio transmitters in the 1920s were expensive, so only the largest or
best-financed radio stations could afford one. Most of the country’s radio
stations just bought the parts and built their own rigs.
(In 1923, only 40 out of almost 600
radio stations in the country had factory-built units, all of them made by
At that time there was nothing like
today’s FCC type notification process. Instead, a station would call the local
government radio inspector, who would visit the station, make some measurements
and certify the transmitter. Even with that safeguard, the mechanical and
electrical quality of these early rigs varied greatly.
Here we see a good view of an early
home-brew rig at WFBE in Cincinnati.
In 1927, WFBE was listed as operating
with 250 watts from the Garfield Hotel. We see the power supply in the
left-hand cabinet, with its light-switch controls, and the RF section on the
right. The tubes probably are RCA UV-204As (for more on those, see home.comcast.net/~n6jv/uv204a.html).
The cabinet appears to be a metal frame
with wooden panels, and the front and sides are left open to provide for
excellent convection cooling. A “Warning” sign serves as the only safety
protection for the operator (OSHA would certainly not approve!).
Even so, this was probably one of the
neater construction efforts from radio’s first decade. It’s similar in
appearance to a Loy Barton transmitter seen in a Radio World article by James O’Neal in the Feb. 1
The use of so many homemade
transmitters created some heated disputes during radio’s early years.
Before 1926, AT&T’s Western
Electric was the only commercial manufacturer of broadcast transmitters, as it
held the patents for many of the basic circuits that were needed to build a
broadcast transmitter, including oscillators, modulators and even the vacuum
tubes themselves. In short, most radio stations in the country were in
violation of their patents by building and using their own transmitters without
In 1923, AT&T sent letters to the
“infringing” stations offering to license their patents for a one-time fee of
from $500 to $3,000 per station, depending on the station’s power. However
during the next year, only 40 stations acquiesced to paying the fee. The main
cause of the stations’ resistance was a clause in the contract prohibiting the
stations from broadcasting programs for profit (in other words, selling
advertising). AT&T went so far as to refuse to lease broadcast phone lines
to stations that didn’t sign the agreement.
Finally, as a test case, the company
brought suit against WHN in New York. The case eventually was settled out of
court by the station, which conceded to all the company’s terms, but the case
had been such a public relations disaster for AT&T that afterwards they
quietly forgot about the patent license issue.
Eventually, as the fundamental patents
expired and more manufacturers were allowed to enter the transmitter business
in the 1930s, factory-made transmitters became the rule rather than the
Schneider is a lifetime radio history researcher. This is one in a series of
photo features from his collection. Write him at email@example.com. Comment to firstname.lastname@example.org.