Publication 20 of the Radio Amateur's Library
During the 1950s and into the '60s, amplitude modulation (full carrier) was replaced with single sideband as the mainstream voice mode for high frequency and weak signal operation. This publication provided information to assist those amateurs who prefer to construct their own equipment. It also served to provide a means to understand the new mode better for those that fueled the rapid proliferation of commercial SSB gear for the amateur market. Five known editions, 1954-1970.
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