germanium transistor in a place of a ge-diode

[mat]

I would like to try the russian germanium transistors as a ge-diode. Can I measure what two legs to solder together with a multimeter and how about the polarity 

Any suggestions ?

Thanks,
Matti T.

[petemoore]

  Ge diodes break over at about .6v, the same type of element exists between base/emitter of transistor.
  You can find the voltage threshold and polarity of the B/E diode with a DMM set to diode mode.

[Mark Hammer]

If you have diode-testing on your meter, you should measure about 220-250mv forward voltage between emitter and base, and base and collector, and nothing if your probes are connected to emitter and collector.  As far as I know, you can use whichever orientation you want.

Pete, I think you were thinking Si while you were writing Ge.

[PerroGrande]

If you know the pin-out, you can use the base-emitter junction of a Germanium tranny as a diode.  I've actually done this (within the last few days) just to see how it sounded, and it actually worked pretty well. 

[MetalGod]

I've been unable to get those Russian Ge's to bias up - all I've used them for up till now is diode clipping.

[mac]

Be sure to measure collector and emiter in both directions, and base to collector and base to emiter in reverse way, because sometimes you get some reading that indicates that the transistor is bad. Also see if the voltage drop across base and emiter and base and collector are similar.

mac

[mat]

Is there only one way to use ge-transistor as a diode ? Not two ways like on the mosfets ?

Thanks for the answers.

[mat]

This picture shows the two values I got from it with the multimeter at diode setting.



So which leg would be the anode and which one the cathode ?

[BubbaKahuna]

IIRC, Cathode is next to the little metal tab or colored dot marked on the tranny.

[mat]

IIRC, Cathode is next to the little metal tab or colored dot marked on the tranny.

In this case (on the picture of the measurements) would the cathode be the pin 2 (when looking at the voltages) ?

So would it be identical (to use as an diode) to use the transistors pins 1-2 (anode-cathode) or pins 3-2 (anode-cathode)

Should the remainind leg to be soldered to the pin 2 (cathode) ?

Sorry, I'm an ass on this 

[birt]

the remaining leg can remain unsoldered. but since it's a common cathode you can connect both anodes too and then you have 2 Ge diodes in parallel. if you do the same with an NPN Ge transistor you have two diode pairs anti-parallel.

[mat]

the remaining leg can remain unsoldered. but since it's a common cathode you can connect both anodes too and then you have 2 Ge diodes in parallel. if you do the same with an NPN Ge transistor you have two diode pairs anti-parallel.

Thanks birt ! Good tip 
Would the two diodes be 100% similar or would there be a difference as in mosfets ?

Thanks,
Matti T.