A SURVEY OF EARLY POWER TRANSISTORS

by Joe A. Knight

PHILCO 1950s GERMANIUM POWER TRANSISTORS

ABOVE, L-to-R:   Philco had publicly expected the conversion to transistor car-radio devices would occur in the 1958 model year.  However, it had actually began with the 1957 model year and may have caught Philco a little off-guard as their first output devices came out several months after most of the their competition.  Later in 1957, Philco released another pair of Germanium PNP in-house numbered devices, the "T1167" (rated at 60v) and the "T1168" (rated at 80v).  By mid-1957 Philco had released their RETMA counterparts, the "2N386" and the "2N387" (first two items shown), both rated at 12.5 watts of dissipated power.  Later in 1957/58, Philco released more in-house types (see the bottom row two), like the type "T1316", which now used a more common package with short straight pins, allowing for easy socket plug-in and replacement.  Philco's interest in the car-radio market is also indicated in the last top-row item, the "AR-6", from early 1957.  The AR may stand for 'Automobile Radio' (??) as the Transistor substitution guides list several Philco AR-types in the TO-27 style but also in the TO-3 style.  None of the later have turned up to date (although Clevite made an "AR-12" TO-3 type, but for whom??).  This would seem to validate their major interest in producing a wide variety of output devices for the automobile market, but again, maybe too late & too different.  Such were the state of corporate affairs that the Ford Motor Company acquired Philco in late 1961.  The Philco-Ford  semiconductor business continued for many successful years and in other forms but by the end of 1961 Philco was no longer listing any Power Transistors in their inventory.  While the funny-looking Philco 'flying saucers' may not be that interesting to most collectors, they do occupy a notable place in Power Transistor history.

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