Does anyone know of any Germanium Transistors?

[Izzy]

Hello,

Its been a long time. But anyway, does anyone know of any Germanium Transistors that is being manufactured currently or in the past few years?
Or is it like no one makes  them anymore?

I am actually looking for a transistor with 0.2V to 0.4 V drop across Base emitter. If anyone knows of one please let me know.
Its max collector current should be > ~300mA. And hfe > 80 if preferred.

Thanks in advance.

[nokaster]

check out small bear electrics.
he'll help you out!

[brett]

Hi
Most Ge devices are quite old stock.

I am actually looking for a transistor with 0.2V to 0.4 V drop across Base emitter.

All normal Germanium transistors have a working base-emitter voltage of about 0.3V.

Its max collector current should be > ~300mA. And hfe > 80 if preferred.

That's quite a lot of current, so it'll have to be something other than the small signal devices we usually use in stompboxes (where Ic of 100mA is common).  hFE varies all over the place, but is usually lower when current-handling capacity is higher.  So hFE>80 might be a bit hard to find when Ic>300mA.  There's a fellow in Sofia, Bulgaria, who has been selling Russian devices, including power devices, on e-bay.  You might check him out.
cheers

[Izzy]

Thanks !

I will check it out.

[amz-fx]

I have a large stock of the 2N1309 germaniums...  mil-surplus, low leakage and high gain. Check my homepage.

regards, Jack

[JDoyle]

That's quite a lot of current, so it'll have to be something other than the small signal devices we usually use in stompboxes (where Ic of 100mA is common).

Using ohms law, 100mA is 9 Volts through 90 ohms - still an awful lot of current for a stompbox, I think you added a zero or two, more likely two...

[Izzy]

No, actually it is not for a stompbox. I was just wondering if such Ge transistor is still under production. I was trying to use it as a switch to power my circuit On or Off. 

Thanks for the help.

[The Tone God]

I was trying to use it as a switch to power my circuit On or Off. 

Then why are you using a Ge tranny ? Why not something better suited like a FET ?

Andrew

[Izzy]

I was trying to regulate 5V using a 6V battery which can go upto 7.1V and as low as 5.0V. So I cannot afford 0.7V drop across base and emitter. If I have only 0.3V drop I may be able to regulate 4.8V to 5V when I have >~5.3V  left in the battery.

Not a circuit expert but thats what it looks like from a Pspice simulation.

Well sorry abut my last post its not a switch but all the current to the circuit passes through the collector and emitter.

Here you go... series regulator.

[brett]

Sorry if I caused any confusion with the 100mA thing.   -  I meant Ic MAX of 100mA.  Except for digital stompboxes, I don't think I've seen one chewing 100mA, and that's for the whole circuit.

As far as the regulator circuit goes...  I don't think you need much hFE.  I've seen these old regulators built using 2N3055s, which used to have hFEs of 30 to 50 (modern ones have more).   With Ge, remember to keep the package cool with a big heatsink (Ge melts at a *much* lower temperature than Si).
good luck