Re: Transistor Tester and Germanium

Posted by balno on Apr 08, 2018; 8:06am
URL: http://guitar-fx-layouts.238.s1.nabble.com/Transistor-Tester-and-Germanium-tp42581p42599.html

Anyway :

Tester off.
GT404B (Ge-NPN) connected to the tester.
press on test : hfe = 79.3 / leakage (Iceo) = 170
after 10 seconds :
press on test : hfe = 80.4 / leakage (Iceo) = 160
after 10 seconds :
press on test : hfe = 81.8 / leakage (Iceo) = 150
after 10 seconds :
press on test : hfe = 84.8 / leakage (Iceo) = 150
after 10 seconds :
press on test : hfe = 86.8 / leakage (Iceo) = 150

To me, this one is OK, leakage is fairly reasonable, even great and HFe is perfect for my project. Still confused by the variations in time, but I guess accuracy is largely sufficient for what I'm doing (sorting a bunch of trannies in 3 bags : leakage < 300, leakage < 500 and leakage > 500). Meanwhile, I plan to let my circuit warm up a little bit (5 to 10 minutes) when biasing, I think this is the point.


Thanks for your help.