GT404b transistors acting weird

Started by phector2004, September 24, 2010, 09:04:55 PM

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phector2004

Hi everyone,

I was scratching my head bare last week trying to get leakage and gain of some russian transistors I got off ebay from "gordelux"
Seemed like a deal, but they don't seem to do anything...

Has anyone had good/bad experiences with this seller?

Using RG's transistor tester flipped for NPN, I get a very low leakage current (~5uA!).
Problem is, there's no apparent gain. I thought I had gone crazy after going through the beginning of RG's FF article 6 times, rebuilding the tester 10 times, testing many transistors, and finding a slight DROP in voltage when testing for total hfe. Let it sit for a week, now I'm seeing the same thing!
Also, doing a diode test to confirm the supplied pinout, E ->| B, as expected, C ->| B, as expected, but I also get a current reading from emitter to collector (leakage, maybe?)

I'm certain its not my setup, as I had the bright idea of testing it with a different Ge transistor today and got a valid leakage and gain measurement (~200uA, 90 hFe)


EDIT: Got this sorted out after trying out a few more. A sideways pinout as well would have saved me some top/bottom confusion. These aren't suspiciously low-leakage but rather very temperature sensitive. 3 seconds of handling brings the leakage resistor voltage up to 1V... Gains aren't astonishing but they'll do for what I have in store  :icon_twisted: