Trying to measure russian MP39B and IT308B (GT308B) trannies

Started by bancika, August 11, 2012, 04:21:16 AM

Previous topic - Next topic

bancika

I bought 20 of each mp39b and it308b for bonamassa fuzz and I'm trying to measure gain and leakage using RGs method. For mp39b it worked fine, all measured gains 30-45 and leakage 100-150uA. However, I can't figure out it308b. It's different pinout (ECB instead of EBC), so I swapped B and C legs and measured a few. All measure leakages around 10uA which is much less than mp39b, but what worries is that all measure gain around 30. It's supposed to be over 60-70. What am I doing wrong? My battery is 9.3V. I measure 9V at the base and about 0.3V at the collector.
Thanks!
The new version of DIY Layout Creator is out, check it out here


IvIark

I've bought a few batches of *T308* (sold under various guises, GT308B, GT308V, IT308B, IT308V depending on how they were mixing the languages) and out of a couple of hundred the lowest measured hfe on my Peak was 54 and they ranged from that up to 95.  All showed zero leakage on the Peak. 

I bought all mine through orpheus_2005 so I'm not sure how they differ from seller to seller.

bancika

is it normal to get 9V on the base? I'd assume that it'd be much closer to zero than the voltage of the battery.
The new version of DIY Layout Creator is out, check it out here