Wesley Schum, pioneer in development of
SSB communication equipment

In the 1940's the principal mode of voice communications, as used by amateur, commercial and military radio services, was Amplitude Modulation (AM).

At 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.

Many, 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.

Central 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 frequency.

Effectively, 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.

Central's 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.

Central 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.

Central became, in late 1958, a subsidiary of Zenith Electronics and continued transmitter production until 1962 when the Company was suddenly, and unexpectedly, deactivated.

For 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.

A 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 survive, today.

Tusa 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 scheme.