TRANSISTOR MUSEUM™

Historic Transistor Photo Gallery 

By the mid 1950s, the proprietary “CK” device identification was in transition for most Raytheon devices to the more standard “1N and 2N” industry style.  The diodes in the above packages are the red epoxy type, and are labeled as either 1N66 or CK705.  

RAYTHEON CK705 GERMANIUM

 CRYSTAL DIODE

Page 2

The CK705 Replacement Guide

1N34	1N34A	1N43	1N45
1N46	1N48	1N51	1N66
1N69	1N90	1N115	1N126

Above is a section of replacement guide, adapted from a 1950s Raytheon Germanium Crystal Diode publication.  It seems that Raytheon was positioning the CK705 as the “Universal” general purpose germanium diode.

Above is a section of an ad by Raytheon in the Nov 1951 Proceedings of the IRE, affirming a leadership position in germanium device technology.  At right is a version of a 1951 Raytheon publication illustrating the “Seven” new features of Raytheon Germanium Crystal Diodes.  The yellow epoxy CK705 diodes of this vintage frequently experienced performance degradation due to moisture infiltration.  

A detailed view of  early 1950s

Raytheon yellow epoxy CK705 construction.

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