Transistor Museum Photo Gallery Raytheon Blues Germanium Transistor Hobby

TRANSISTOR MUSEUM™

Historic Transistor Photo Gallery

Raytheon Blues – “High Performance Blues”

Photo of High Performance Raytheon Germanium Transistors

Photo Essay Commentary

Raytheon developed a line of higher performing germanium transistors, all blue-cased, starting in 1955. These devices were intended to be used in applications, such as commercial radios and computer circuits, where higher switching speed was required. For several years, these transistors were competitive with other germanium transistor types available at the time. For example, the CK761 (2N113) was used in switching circuits for the Bell Labs “Leprechaun” digital computer developed in the mid 1950s, along with the 2N137 transistor from GE and the Surface Barrier transistor from Philco. It is also interesting to note that Raytheon used a double numbering system for some of these transistors, stamping with both the standard “2N” sequence as well as the proprietary Raytheon “CK” sequence. These Raytheon devices were all made using the alloy junction process that was the primary transistor technology of the time. The “high performance” aspect of the devices was attributed to (1) faster switching speeds, up to a blazing 20Mc for the CK762, and (2) hermetically sealed metal cases which worked much better than the earlier plastic case style. Most the remaining metal cased devices of this type are still functional.

For a spectacular photographic tour of the various commercial radios of the time which used Raytheon blue-case transistors, use this link: http://www.bobmcgarrah.net/. Bob has documented a number of historic radios which sparkle bright blue when the circuitry is examined.

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