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Hybrid tellies · 25th Sep 2005, 5:48 pm

Just a further thought, mention has been made whether these whiskers grow whilst equipment is powered up or not.
I notice from Chris Walters pictures of the opened up OC171 transistors that the whiskers grow from the case inwards. Could this be down to a polarity thing as well as the type of metals used?
As far as I know the case (or screen) is connected to chassis which is positive in relation to the other electrodes particularly the collector which would explain why the most common failing of AF117 transistors is the collector screen shorts.
It would certainly be interesting to see what our friends at NASA make of those AF114's Paul has sent them.

25th Sep 2005, 5:48 pm	#14
Hybrid tellies Nonode Join Date: Jan 2004 Location: 1966-1976 Coverack in Cornwall and Helston Cornwall. 1976-present Bristol/Bath area. Posts: 2,965	Re: Whiskers in germanium transistors etc Just a further thought, mention has been made whether these whiskers grow whilst equipment is powered up or not. I notice from Chris Walters pictures of the opened up OC171 transistors that the whiskers grow from the case inwards. Could this be down to a polarity thing as well as the type of metals used? As far as I know the case (or screen) is connected to chassis which is positive in relation to the other electrodes particularly the collector which would explain why the most common failing of AF117 transistors is the collector screen shorts. It would certainly be interesting to see what our friends at NASA make of those AF114's Paul has sent them. __________________ Simon BVWS member