the 1940's the principal mode of voice communications, as
used by amateur, commercial and military radio services, was
Amplitude Modulation (AM).
the conclusion of World War II, great numbers of servicemen
who were exposed, for likely the first time, to two-way radio
communications were bitten by the radio "bug" and
flocked to the Amateur Radio Service. The large numbers of
operators, coupled with the limited frequency resources available
to amateurs, led to near intolerable levels of AM voice interference.
in their backyard workshops, looked for ways to cram more
voice signals into the fixed amount of spectrum (sounds familiar,
doesn't it!). A few investigated single sideband, suppressed
carrier technology and by 1951 several test stations were
operational on the new mode.
Electronics is generally credited with giving the initial
push that got amateur single-sideband off the workbench and
into the ham shack. The Company's first commercial product,
the Central Electronics 10A was formally released in September
1952. Central's 10-A took Don Norgaard's "Single Sideband
Junior" exciter concept (originally featured in General
Electric's Ham Notes) and made it into a viable system. The
10-A used the hetrodyne scheme whereby the single-sideband
signal was first generated at 9MHz and later mixed, using
either crystals or an external VFO, to the desired output
the 10-A used the hetrodyne principal in a manner typical
for high performance receivers of that time and was the first
amateur transmitter to utilize a mixing scheme. The result
was a stable, low cost single sideband exciter which was within
the financial grasp of virtually any amateur.
founder, Wes Schum, W9DYV, was a major influence in the single-sideband
movement. His combination of excellent engineering skills,
the ability to explain complex topics in easily understood
terms, his unstoppable spirit and light-hearted personality
were then, and remain today, unmatched.
continued to manufacture a line of high quality products,
which culminated with the Company's 100V and 200V transmitters.
Designed by Schum and his lead engineer Joe Batchelor, these
transmitters were decades ahead of their competitors.
became, in late 1958, a subsidiary of Zenith Electronics and
continued transmitter production until 1962 when the Company
was suddenly, and unexpectedly, deactivated.
collectors, the 100V and 200V represents the highest standard
of vacuum tube transmitters ever made. They offer, today,
robust reliability, excellent audio quality and command a
place in any serious radio equipment collection.
total of fifteen hundred 100Vs and five hundred 200Vs were
manufactured. Due to their limited product and relatively
high price ($800 in 1959) few were ever scrapped and most
maintains a close association and friendship with Mr. Schum.
Both are jointly involved in a variety of projects, which
include several new Comtronics products, the expansion of
Schum's high voltage test set product line, continued Central
Electronics equipment support and development of high-power
broadband amplifiers using the Batchelor broadband coupler