Am I going mad? Germanium HFE testing

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Am I going mad? Germanium HFE testing

Heath
Okay so I needed some higher gain NPN germaniums and the ebay listing was for AC127k transistors.  

The listing title is:
10 X AC127K NPN GERMANIUM TRANSISTOR TESTED 90+ HFE



However, I've got my little germanium tester out, a good battery with power and ground leads reversed, using my multimeter on DC Voltage, leads reversed for NPN testing and I'm getting bizarre results.  I've given them time for the settle from temp differences and triple checked the pinouts.










Does that make sense at all?  Any thoughts?  I don't want to message the guy that he sold me crap unless I know for sure.  I'm also going to try plugging them into a circuit and see how they sound, as a sanity check.

There's no way I can build Fully Functional Ge Deathstar with these measurements.
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Re: Am I going mad? Germanium HFE testing

rocket88
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something does seems off, but i'm not sure what. there could be an issue with the calculation making you off by 1 decimal, so instead of 14hfe its 140hfe.

but, on a side note. i was having similar issues with readings of the Ge transistors  i was buying, so i ended up buying a dca55 and never looked back. it just ended up being easier. i created a small testing board with a transistor socket and two pins to connect the probes to, so i can just put one in, take the reading, then move on. plus the hfe reading you get takes leakage into account.
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Re: Am I going mad? Germanium HFE testing

IvIark
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In reply to this post by Heath
Well they look shit to me, which isn't too much of a surprise with most NPN germaniums.  The only decent ones I ever bought were MP38's.

My AC127s were all pretty high gain though, but the leakage was shocking.  Have you tried a known good transistor in there like an MP38 or even a PNP to see if the figures look realistic?
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Re: Am I going mad? Germanium HFE testing

Heath
Yep, I've used the same circuit to measure all of my germaniums and never had much trouble.

On an odd note, though, I built Bjorn's candy apple fuzz and initially tested it with some MP38as at around 65 hfe.  This is what I bought the AC127ks for.  I swapped out the MP38a test germs and put in a couple of the AC127ks and the sound is definitely a bit louder and crispier, so there is a noticeable difference, and not one that I would think would suggest low gain.  However, I haven't gotten the Fuzz circuit with too long of a damn name working right yet, so I'm still not positive about what's going on.