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Michael Terrell Michael Terrell is offline
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Default Vintage transistors and tin whiskers

On Sunday, May 17, 2020 at 10:15:34 AM UTC-4, Cursitor Doom wrote:
Gentlemen,

I have some old OC171 transistors from an old Eddystone short wave radio
I'm restoring. The problem is I suspect they've developed whiskers, as
the resistance readings from e,c and b to the screen connection are all
far too low (sub 10 ohms). A colleague has suggested blasting the
whiskers by tying the ecb leads together and zapping them against the
screen with a 500nF cap charged to 500VDC. Now this seems a bit counter-
intuitive to me and I'd have thought higher current lower voltage would
be safer for these delicate germanium devices, but WTF do I know?
Is it feasible to remove the whiskers by this sort of method or any other?



If the Tin Man in the Wizzard of Oz tried to grow a beard, they would be really big tin whiskers. ;-)