[sdiy] Ge transistor tester weird results

[Carl Pilman]

Hi!

When I have tested Ge-transistors for fuzz pedals, I've used R.G. Keen's
circuit for testing leakage and hFe.

http://www.geofex.com/Article_Folders/ffselect.htm

I let the transistor cool down from the warmth of my fingers handling them
before reading the values since small temperature changes have a huge
impact on leakage and hFe.

Den tis 8 feb. 2022 kl 09:26 skrev Michael E Caloroso via Synth-diy <
synth-diy at synth-diy.org>:

> Ge devices are notorious for reverse bias breakdown.  That would confuse
> any auto detection test algorithm.  The only bench test equipment that
> would work for these is a curve tracer.
>
> I would never trust any NOS Ge devices on the market.  By now the supply
> will have gone through multiple hands, with good ones retained and flaky
> ones passed to unsuspecting buyers.
>
> MC
>
> On Tue, Feb 8, 2022 at 2:23 AM Mathias Neumann <alfrede at opferindustries.de>
> wrote:
>
>> Hi at all,
>>
>> here is the github repo for all documentation and firmware.
>>
>> https://github.com/kubi48/TransistorTester-source
>>
>> https://github.com/kubi48/TransistorTester-documentation
>>
>> or this with changelog in the pdf's
>>
>>
>> https://github.com/madires/Transistortester-Warehouse/tree/master/Documentation
>>
>>
>> Mathias
>>
>>
>> Am 08.02.22 um 00:49 schrieb René Schmitz:
>> > On 07.02.2022 23:08, cheater cheater wrote:
>> >> Thanks! What sort of things should I be seeing if I connect only CE
>> >> or only BE?
>> >
>> > BE would act like a Ge Diode.
>> >
>> > If it makes no difference whether the Base is connected, then you are
>> > measuring only the leakage, and there is no transistor effect.
>> >
>> >
>> > --
>> > synth at schmitzbits.de
>> > http://schmitzbits.de
>> >
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