TRANSISTOR MUSEUM Historic Transistor Photo Gallery
Transistor Size (3/4” Diameter Dome X 1/2” H) Date Code 643 (1956 Week 43) Packaging- Cardboard Box	CBS HYTRON 2N155 TYPE Germanium PNP Power Alloy Junction USAGE Audio/Hobbyist DATE INTRODUCED 1956 CASE STYLES Black Metal (Early) Silver Metal (Later) AVAILABILITY Common (High Volume Production)
HISTORIC NOTES CBS Hytron was never a major producer of semiconductors, but did have an early success with germanium power transistors. The 2N155, shown in the photo, was one of first power transistors available to the general public, and was used in a variety of applications which required more power handling capability than the smaller types common at the time. Examples of applications of these early power transistors included audio output for hybrid car radios, power supply switching circuits and general hobbyist/experimenter usage (small audio amps, megaphones, etc). The 2N155 could be substituted for a number of other germanium power transistors, including the 2N176 and 2N301. CBS Hytron was bought out by Raytheon in the late 1950s, but transistors were still produced using the CBS name until the mid 1960s. The Raytheon labeled version of the 2N155 sold for $3.75 in the 1958 Burnstein Applebee Radio Electronics catalogue, and the CBS labeled version sold for $2.78 in the 1962 Lafayette Radio catalogue.
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