Transistor Museum Early Germanium Power Transistor History by Joe Knight Westinghouse Page 2

A SURVEY OF EARLY POWER TRANSISTORS

by Joe A. Knight

WESTINGHOUSE 1950s/60s GERMANIUM

POWER TRANSISTORS

For whatever reason, Westinghouse apparently did not come out with any new transistor designs until early 1956. These new types were identified as the "XD" series and were all Germanium Power Transistors, rated at 15 watts of dissipation. The first two were for audio amplification and were called the "XD5081" (see below) with a flange base (again, another unusual basing design, this after most companies were coming out with the standardized TO-3 case construction). A same rated version without the flange was called the "XD-5082". Another switching application pair were also released later in 1956, the flanged base "XD-5083" and the un-flanged "XD-5084" (see below).

ABOVE, L-to-R: The first device is a pre-production hand-painted item, a "XD-5084", the un-flanged switching type, likely from early 1956. The second device as a production audio type, the flanged "XD-5081", from mid-1956.

Go To Westinghouse Early Power Transistors, Page 3

Joe A. Knight Early Power Transistor History – WESTINGHOUSE Page 2