Introduced by Sylvania in 1946, the 1N34 germanium
diode has been in production ever since and continues to be the most
popular and universally recognized diode available. By the early 1950s, the 1N34 was
manufactured by other companies, including CBS-Hytron, Radio Receptor, RCA
and Raytheon. Both Sylvania and Raytheon marketed the 1N34 heavily to the
hobbyist and experimenter market, and published numerous booklets
containing 1N34 construction projects – best remembered is a simple AM
radio, using the 1N34 with very few other parts.
A large cylindrical ceramic case with green lettering
was the earliest version produced by Sylvania. The clear glass case style was introduced by Sylvania around
1950, with the label 1N34A. Raytheon used a proprietary number, CK705, for
their early 1N34 equivalent diodes, but changed this identifier in the
1950s to 1N66 (See the photo above right).
Sylvania and Raytheon books from the 1950s list the CK705, 1N66 and
1N34 (A) as interchangeable.