WHat Germanium Transistors??

[Giaime]

And what about the AC188? I got 3 of them for cheap in a local electronic store (still has a cupboard full!) and thought of a Ge Fuzzface, I tried them but I was getting bad gating sounds, like that they were misbiased (I used the stock fuzzface values, and a trim for the second transistor emitter). My DMM says they have a gain of around 180, and I tried to measure leakage and I get around 10-14uA, but I'm not sure of my results.

What are their specs? what are they supposed to do? the guy in the shop told me they were replacement parts for AC128....

[stm]

Sadly enough, starting with only three devices is very likely you won't find a "magic" couple with 70/130 hfe's and low leakage.

I would suggest you make up the suggested Ge transistor tester and ask the clerk if he would allow you to select the trannies from his box with your test rig. Then, you could just measure lots of them and pick two or three matched pairs, which you can later test by ear.

Also, as someone already mentioned, "out of spec" Ge trannies make good Ge diodes.

Regards,

STM

[Giaime]

Mine tests about 180 in hfe, and usually leaky ones are in the range of 500... so can I suppose mine are good enought?


Oh, I have loads of Ge diodes... also that shop has another cupboard of them full... they usually give them to me for free. Also the Ge trannies were at 50 euro cents... I'm starting thinking of buying them all, and sell them on eBay