Transistor Museum Early Germanium Power Transistor History by Joe Knight Raytheon Page 3

A SURVEY OF EARLY POWER TRANSISTORS

by Joe A. Knight

RAYTHEON 1950s/60s GERMANIUM POWER TRANSISTORS

ABOVE, L-to-R: As mentioned above, Raytheon had the rights to second source some of the CBS output devices in the late 50s/early 60s. The first item seems to be a close copy of an earlier CBS device, the "HD463" but now labeled as the RAY "HD4-65" (from 1962). Although, now it has a threaded bolt heat sink connection as opposed to the earlier bolt hole and has wire leads as opposed to the original short pins (see the CBS page). This same device also appears also as a Raytheon in-house number version called the CK415. Hard to say which one came first. The middle item is a copy of the CBS 2N158 but is now labeled the RAY 2N158 (from 1963). Some may wonder if these items were just re-badged CBS items? It's hard to tell from the evidence at this point, although by the early 60's one would assume the original CBS inventory would have run out. Anyway, its likely Raytheon bought all the CBS manufacturing machinery so most new items would look much like the original devices. The last item is another example of Raytheon second sourcing another manufacturer, this time the TI 2N389/424 type, a NPN Silicon output transistor, released in late 1957. This is a cut-open example (still works) of the Raytheon version, likely made through a cross-licensing agreement, and made in the early 1960s, just prior to their semiconductor endeavor winding down. This item relates to the original Silicon semiconductor development work Raytheon did (and shown on Page 2, DEV 16) and shows they were well prepared to move into this new market technology.

Thusly, Raytheon backed into the power transistor market - and not as a leader or innovator. In the end this was part of their downfall and withdrawal from the semiconductor marketplace.

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Joe A. Knight Early Power Transistor History – RAYTHEON Page 3