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Caduff Method of Single Sideband

Amateurs are quite familiar with the Filter and Phasing methods of developing single sideband analog signals. Some may even be familiar with the Weaver Method, but have you heard of the Caduff Method? Don’t feel bad…neither had Wes Schum. Yet that changed in late November, 1959 while up to his eyeballs in getting the 100V Transmitter into final production and out the shipping gates.

Just after Thanksgiving, Wes received an interesting letter from Gerald Caduff, KØIQZ. An instructor at Pueblo College, Caduff had developed what appears to have been a novel method of developing single-sideband. One unique attribute of the Caduff System was that in his design there was no need to suppress the unwanted sideband since it was not generated in the first place! Needless to say, such a device would have eliminated the need for expensive crystal/mechanical bandpass filters (big gulp from the Collins lads?). The key to Caduff’s design: a special cathode ray tube.

Zenith gave careful consideration of the Caduff design and found that it was likely patentable. Unfortunately, the timing could not have been worse for Caduff and Central Electronics. Just weeks before Zenith completed its technical review of Caduff’s design, a decision had been made to cease Central’s work in the field of single sideband communications and to focus on consumer electronics products.

Apparently, Caduff subsequently abandoned his quest for patent protection. Sadly, Central Electronics’ new home in Paris, Illinois never made one amateur radio product…but plenty of console stereos and many thousands of FM stereo test sets used by radio service shops throughout the nation. Yet, KØIQZ’s work as the lone inventor seeking a better way is an excellent example of entrepreneurism and the American Spirit.

Caduff Single Sideband

© 2012 Central Electronics