germanium transistor question

[rutabaga bob]

With all the stuff I've built, I have never made anything using germanium transistors, even though I have some around the house.  My question is: does it matter if you use transistors originally meant for RF?  I have some scavenged from an old table radio, and the numbers on them are only manufacturer's codes, not standard stuff like 2sb, etc..  There's no easy way of knowing their original function.
Thanks!   - Larry
EDIT: I'm getting ready to build a Fuzz Factory.

[PRR]

> does it matter if you use transistors originally meant for RF?

No.

In the grey days, radio factories bought unsorted transistors (often rejects from fussier factories) and tested them. Best find was low-noise RF. Next bin was RF. Any non-dead fallout from those tests was used for audio.

[rutabaga bob]

Thanks, Paul!   

[LightSoundGeometry]

> does it matter if you use transistors originally meant for RF?

No.

In the grey days, radio factories bought unsorted transistors (often rejects from fussier factories) and tested them. Best find was low-noise RF. Next bin was RF. Any non-dead fallout from those tests was used for audio.

Paul, I would rather ask you than google, what were all the different device applications other than switching and amplifying ? Looks like the frequency is in play here ..does lower frequency equal lower noise ?

[PRR]

> does lower frequency equal lower noise ?

No (not the way you think). With luck, they made a part with high speed and low hiss. Ge fabrication isn't all good luck. You get a lot of slow and hissy parts. However in any long chain of amplifiers, the first stage is most critical, the end of the chain can use less-good parts.

> I would rather ask you than google, what were all the different device applications

Isn't this like asking: what were all the uses of wrought iron?

And isn't Google better at "About 4,030,000 results" than my sore fingers and painful butt?

[LightSoundGeometry]

> does lower frequency equal lower noise ?

No (not the way you think). With luck, they made a part with high speed and low hiss. Ge fabrication isn't all good luck. You get a lot of slow and hissy parts. However in any long chain of amplifiers, the first stage is most critical, the end of the chain can use less-good parts.

> I would rather ask you than google, what were all the different device applications

Isn't this like asking: what were all the uses of wrought iron?

And isn't Google better at "About 4,030,000 results" than my sore fingers and painful butt?

I dont trust google and you guys are the best 

[amptramp]

The first RF germanium transistors were the surface barrier type made originally by Philco in 1953.  I recall designs using the SB100 in Radio Electronics and a few other magazines in the 1950's where these transistors were used in CB and 10 metre band designs up to 30 MHz.  This technology is described here:

https://en.wikipedia.org/wiki/Surface-barrier_transistor

These were PNP transistors, as were most early germanium transistors, so be sure your design can use this gender of transistor.