TRANSISTOR MUSEUM Historic Transistor Photo Gallery
Transistor Size (5/16”L X 1/8”W X 5/16”H) No Other Markings Transistor Size (1/8” OD X 5/16”H) No Other Markings	SONY 2T76 TYPE Germanium NPN Grown Junction IF Amplifier USAGE Commercial Radio IF Circuitry DATE INTRODUCED Mid 1950s CASE STYLES Grey Metal (1957) Silver Metal Round Case (1958) AVAILABILITY Rare in the U.S. Common in 1950s Sony Radios
HISTORIC NOTES The Japanese company Sony was an early manufacturer of germanium transistors. There are various accounts of how Sony acquired a license to manufacture transistors from Western Electric (see the book “A Crystal Fire” by Riordan and Hoddeson for detailed coverage). The first commercial quality Sony germanium transistors were of the grown junction type, which had been developed originally at Bell Labs in 1951. The 2T76 shown above in the grey case style is an example of this transistor type. By proper control of the doping and base layer width of the grown germanium seed used to manufacture this type of transistor, reasonably high frequency performance could be achieved – because of this higher frequency capability, the 2T76 was used in the IF and converter circuitry of most all Sony radios until the late 1950s, beginning with the TR63 (Sony’s first transistor radio available in the U.S. See Alan Kastner’s excellent website for more info on early Japanese transistor radios. The silver cylindrical case version of the 2T76 appeared in 1958. The TI 2N147 is listed in several references as a 2T76 equivalent.
Copyright © 2002 by Jack Ward http://www.transistormuseum.com