TRANSISTOR MUSEUM™ Historic Transistor Photo Gallery
These are two of the earliest Raytheon Blue transistors, first appearing in 1955. Use this link for a detailed Photo Essay of all the many historic Raytheon Blue Transistors. PhotoGallery Raytheon Blues Photo Essay Page 2	RAYTHEON “BLUES” IRIDESCENT BLUE TRANSISTORS TYPE Germanium PNP Alloy Junction USAGE Hobbyist/Radio/Computers DATE INTRODUCED Mid 1950s CASE STYLES Bright Blue Metal AVAILABILITY Common (High Volume Production)
HISTORIC NOTES Raytheon was the most successful of the early commercial transistor companies. By 1952, Raytheon had established a thriving, high volume germanium diode business, so the fundamentals for transistor business were in place. In addition, Raytheon was the leading supplier of subminiature hearing aid tubes, and this market was ready-made for the new transistor technology. By mid 1954, Raytheon had manufactured over 1,000,000 germanium transistors, which was more than all other commercial companies combined. These early germanium transistors were made with black epoxy cases; examples are the CK718 (hearing aid transistor) and the CK721/CK722 (hobbyist transistors). The epoxy case proved somewhat unreliable, so Raytheon began using a metal case for all transistors in 1955. The first metal cased units were painted a beautiful iridescent blue color. This distinctive approach lasted until the late 1950s, and established a unique and historic milestone in the first decade of transistor history. If you were a radio-electronics enthusiast in the 1950s, it is likely that you remember your first “Raytheon Blue”.
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