Up ………. PL
Probably the first alloy-junction power transistor. As for modern conditions, the power of 2 W is not high, but at best average. From the information provided on retrodekan.eu. The transistor was created in 1956 at the IPPT PAN, the team leader was doc. Tadeusz Janicki. On the housing I found only the number 108. The original emitter and collector leads have also been preserved, but the emitter lead has been broken off and re-soldered. The heat is dissipated through the base connected to the housing and the fastening screw. The tester shows that the transistor is OK, although its gain is small.
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