mystery component, HELP !!!!

[iainpunk]

so its 3 legged thing, looks like a black-glass envelope transistor, but it feels different and ticking against it with a screw driver, it sound different than the glass oc71's i have.
the kicker, it has TWO red dots,one on either side... and no further marking, at first i thought it to be a transistor, but it doesn't work at all, tried it in different configurations, and it never conducts both outer legs at the same time, unless the two outer legs are both at a higher voltage than the middle leg.
is it just two Ge diodes in a single package? is that even a thing?

cheers, Iain

[antonis]

Not blurred enough, Iain..

[Rob Strand]

Looks like a ge transistor.   Off hand one example is the OC44, OC45 but there were others in that package.   (Also transistors without the black coating which were used as photo transistors.)


Here's a pic
http://www.tonegeek.com/musicgear/pedals/pnp-germanium.php
and another,
https://www.radiomuseum.org/tubes/tube_oc45.html

Some others, OC70, OC71,
http://www.wylie.org.uk/technology/semics/Mullard/Mullard.htm

EDIT:
Can't find info on the second dot but it could very well be a gain sort thing.

[iainpunk]

it might look like a transistor, but it doens't have any gain, zero.
when i put a current from any of the outer pins to the middle pin, the other pin doesn't go in to conduction like any transistor would, and changing around the outer pins yields the same result
i suspect its two diodes in a single package, maybe from a radio or something, it used to belong to a radio repair-guy who passed away in 2017, and i was the only one in his extended family who cared about electronics, he has more odd stuff in the boxes.

cheers, Iain

[Radical CJ]

I have some old ones of that appearance (OC75s I think) that are so leaky, and the hfe is so low, that they really have no use except as clipping diodes. They look like NOS (long legs like your ones, no solder) so I don't whether they have just "degraded" over the past 50-60 years, or whether they just weren't ever used because they were bad to begin with. 

[Rob Strand]

it might look like a transistor, but it doens't have any gain, zero.
when i put a current from any of the outer pins to the middle pin, the other pin doesn't go in to conduction like any transistor would, and changing around the outer pins yields the same result
i suspect its two diodes in a single package, maybe from a radio or something, it used to belong to a radio repair-guy who passed away in 2017, and i was the only one in his extended family who cared about electronics, he has more odd stuff in the boxes.

It could be a PUT or JFET.   An SCR might be more likely.  They did make small SCRs.

There's also parts called DIACS,  SCS, SBS, SUS.   Some of these parts are in theory 2 leaded but I remember seeing some parts as three leaded (often with the third lead cut).

Can you see any brand on it?

You might be able to look-up some old Mullard or General Electric handbooks.   They sometimes have a section which show cases weird parts.

---------------------
EDIT:
I forgot the UJT that might look like two diodes.

One thing not clear is the voltage drops.    If it's ge then I'm not aware of those more esoteric parts being available in germanium.

[iainpunk]

the voltagedorps read 0,347 and 0,281, so likely to be Ge.
the leakage is near non-existent, the DMM flickered between 0.00 and 0.01 mA when testing for leakage.

probably not an SCR since they don't read like two diodes, but as a diode and a really super high resistance.
if it were an UJT it would have a lot of leakage, right? , also, it would be a CUJT (Complementary Uni Junction Transistor) since the P type material is on the outer pins, not the center one.

it looks like the OC71 / OC75 / OC42 package, but it feels more rubber-ish than the plastic on those glass envelopes.

i think its a double Ge diode in a single package, or a broken device, i'll just throw it in the Ge diode bin, and use it for a green ringer, or other octave/rectifier up device.
i might visit a paranormal person to contact my aunt's father in law, to ask him about the unmarked 3 legged package. hahaha

cheers, Iain

[Rob Strand]

he voltagedorps read 0,347 and 0,281, so likely to be Ge.

Yes, seem like it.

probably not an SCR since they don't read like two diodes, but as a diode and a really super high resistance.

Agreed (I was thinking about that later).

if it were an UJT it would have a lot of leakage, right? , also, it would be a CUJT (Complementary Uni Junction Transistor) since the P type material is on the outer pins, not the center one.

I can't remember the leakage.  It's so long since I wired one up.   I remember it was possible to identity the leads of a UJT using the multimeter, maybe just from which voltage/reading was higher.

it looks like the OC71 / OC75 / OC42 package, but it feels more rubber-ish than the plastic on those glass envelopes.

i think its a double Ge diode in a single package, or a broken device, i'll just throw it in the Ge diode bin, and use it for a green ringer, or other octave/rectifier up device.

The two dots is odd but I couldn't find anything.   Also I could find and dual diodes in that package.   That doesn't mean they didn't exist.

i might visit a paranormal person to contact my aunt's father in law, to ask him about the unmarked 3 legged package. hahaha

You can only try  .