Quote:
Originally Posted by kalee20
The trouble is, it is hard to find PNP transistors with a reverse Vbe of more than 5V, whereas the BRY39 does 60V (from memory).
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The transistor BC640 (pnp) has a reverse Vbe of 11V, which is better than most silicon transistors which are usually around 6 or 7V, which makes the 639/640 pair handy for some applications, plus they are robust for their size. I found this out when testing a few in a specific application that zenered the B-E junction, which is never a good idea, each time its done the hfe degrades a little.