Germanium Treasures, and Questions

[KerryF]

Hey. 

I just recieved some NOS Germanium Diodes and Transistors from Yun today.  I have some nice pictures and a few questions.

Diodes:


NPNs:


PNPs:


Dont Quite Know :


Questions:
1. How can I use my Multimeter to find out if some of my transistors are PNP or NPN (the "Dont Quite Know" ones)
2. Do those different color stripes on the diodes mean anything, like value?  Anyone have a color chart?
3. Any way to use a Multimeter to measure HFE of the transistors?

Thanks,
Kerry

[Seljer]

check a on the past couple of pages, there recently was a thread about identifying what terminal is what on unknown transistors

it is possible to measure hfe with your multimeter (if your multimeter supports it), but germanium transistors have many other attributes (theres an article on geofex about testing them, go read that)

[KerryF]

I will check the other page.

Can you show me on GEOFEX where the HFE and Germanium thing is.  Looked but dont know where to find it on there.

[Mark F]

I will check the other page.

Can you show me on GEOFEX where the HFE and Germanium thing is.  Looked but dont know where to find it on there.

I do believe it's on the "TECHNOLOGY OF" FUZZ FACE page.

[KerryF]

^-Found it!  Thanks!

Another question...

How do I measure voltages of a transistor in a circuit?

Also, is there any way to find out if a transistor is good or a dud?  (Not saying mine are, just wondering for reference).

[Yun]

glad that you got them, buddy 

The last ones are PNP's as well.  i couldn't find a datasheet for the mini pnp's anywhere on the net, man. 

Anyhoo; put that stuff to good use, man.....

[KerryF]

Hey.  Yea thanks Yun. 

All 4 of the last ones?  I think you said there was 4 NPNs so are you sure one of those isnt NPN?

[KerryF]

Again...

How do I measure voltages of a transistor in a circuit?

Also, is there any way to find out if a transistor is good or a dud?  (Not saying mine are, just wondering for reference).

[Yun]

Hey.  Yea thanks Yun. 

All 4 of the last ones?  I think you said there was 4 NPNs so are you sure one of those isnt NPN?

The last 4 of "unknown" germ trannies are PNP, i must have made a typo in our e-mail, man....

[Yun]

Again...

How do I measure voltages of a transistor in a circuit?

Also, is there any way to find out if a transistor is good or a dud?  (Not saying mine are, just wondering for reference).

What kind of multi-meter do you have eh?  My multi meter has sockets right by the HFE setting.  So switch it to the hfe "setting", insert  the transistor into the socket, and.....well....there you have it.

[KerryF]

Mine doesnt have HFE testing.

Still...
How do I measure voltages of a transistor in a circuit?

Also, is there any way to find out if a transistor is good or a dud?

[Barcode80]

set your meter to 10v DC setting (or 20v if you don't have a 10). connect black lead to ground, red lead to the emiiter, base, collector, whichever you want to measure. as long as you have power to the circuit and you don't have a power switching input jack (or do have one and have a cord in it) you should get a voltage reading.

[KerryF]

^-Sweet! Thanks 

[343 Salty Beans]

I find that transistors can often show no signs of being a dud, other than just making the circuit NOT WORK. An audio probe can tell you the transistor is screwed up, usually. It's my best tool for debugging now.