Please help identify these old (transistors?)

Jamdog · April 20, 2016, 08:33:09 AM

I got a bunch of those in an old avionics equipment. I can't say for sure but can assume it's in working order.
They are likely from the 70s

Some have the GE logo, and the only indications I can find are M-75522-1, M-75523-1, M-75524-1, M-75525-1, M-75528-1 and M-75529-1 depending which one. Also all have GE 613 inscription. The majority is M-75522-1.

I can't seem to find datasheets for those old parts.
I'd be interested in using them to get some unique sound, if anyone has ideas I am all ears.

tonyharker · April 20, 2016, 02:07:01 PM

The M-7552x-x numbers I suspect are date codes. The GE613 will be the type number. Probably 2n613s Germanium PNP devices. Are they PNP Germaniums?? Have you tested them?

Jamdog · April 20, 2016, 07:07:54 PM

It's very well possible. I didn't think about date codes and came back empty from my Google search. I've been suspecting pnp transistor, but am unsure of pinout.

I don't quite know how to test them, in fact.

Jamdog · April 20, 2016, 07:26:05 PM

Quick search seem to point that 2n613 are germanium npn

Blitz Krieg · April 21, 2016, 02:23:27 AM

Ge NPN or G E NPN ?

amptramp · April 21, 2016, 10:01:54 AM

Quote from: Blitz Krieg on April 21, 2016, 02:23:27 AM
Ge NPN or G E NPN ?

The diode setting on your DMM will tell you which it is. Junction voltages in the 0.2 to 0.4 range mean germanium. 0.5 to 0.7 means silicon.

duck_arse · April 21, 2016, 10:51:29 AM

it's interesting (!) that these have an emitter tag, but a centre leg to case, from appearances. on some of them. russian-style connection?

Jamdog · April 21, 2016, 10:13:37 PM

Quote from: amptramp on April 21, 2016, 10:01:54 AM

The diode setting on your DMM will tell you which it is. Junction voltages in the 0.2 to 0.4 range mean germanium. 0.5 to 0.7 means silicon.

Negative at the base, that means they are Pnp?
I read between 180 and 190 mili

Except the one with a different casing, that reads around 790 mili and positive at the base. I bet that's why the avionics instrument was considered to be defective: totally wrong replacement!

I whish I'd have kept the transistor sockets...

Anyway, I believe they are functional PNP germanium GE transistors.

What's the best sounding circuit to do with this?

Jamdog · April 23, 2016, 01:20:59 PM

Quote from: Jamdog on April 21, 2016, 10:13:37 PM
Anyway, I believe they are functional PNP germanium GE transistors.

What's the best sounding circuit to do with this?

I am thinking of making a fuzz face, where should I look for PCBs?

(or should I favor a tone bender?)

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Please help identify these old (transistors?)