What would I do with a germanium PNP with an hFE of 18??

[xefned]

I forgot why I acquired these. Are they useful for anything with an hFE this low? (18 hFE, PNP germanium.)

 

[BuddytheReow]

I’d say use it as a diode

 

[derevaun]

Or in a Darlington pair with another low gain PNP, or in a Sziklai pair with a low gain NPN. IME, gonna just stash this one away and get around to doing that sometime I guess.

 

[spi]

I used one like it in a tonebender mk 3. I tried it in several positions but liked it best in Q2.

 

[Giorfida]

Would be perfect for the Mystery Machine, since it’s using a pair of PNP geraniums as clipper dioded

 

[Giorfida]

Would be perfect for the Mystery Machine, since it’s using a pair of PNP geraniums as clipper dioded

*germanium. Damn autocorrect!

 

[xefned]

Would be perfect for the Mystery Machine, since it’s using a pair of PNP geraniums as clipper dioded

Oh wow. That Mystery Maschine does sound magical. I'm afraid I need to build one now.

 

[Giorfida]

Oh wow. That Mystery Maschine does sound magical. I'm afraid I need to build one now.

I just finished mine about an hour ago. Fun little pedal!

 

[MBFX]

I can't remember why I bought these. Are they useful for anything with an hFE this low? (18 hFE, PNP germanium.)

View attachment 65224

Do you have two? Leakage is usually low on these low-gain PNPs, so they make great Darlington pairs for a Rangemaster!

 

[xefned]

Do you have two? Leakage is usually low on these low-gain PNPs, so they make great Darlington pairs for a Rangemaster!

I have 2, yes! Thank you. I will research how to wire a darlington pair. Gracias!

 

[MBFX]

Here you go. Beta (hfe) and leakage multiply in this arrangement, so you can get really high gain!

 

[xefned]

OK, this is great, thank you. The guy I got them from years ago sent a message that the PNPs "should be good for..." [long-forgotten name of circuit.] I can't find his message. (I recall the NPN he he also sent was good for Rangemaster.)

It looks like I can do the darlington trick with either NPN or PNP, which may bring 2 of these into range, possibly at the risk of increased leakage. But perhaps that's not a bad thing.

 

[spi]

BTW the first pair of transistors in a tonebender mk3 are a darlington pair (which is why I chose to use my low hfe transistor in that circuit).

 

[xefned]

The Tonebender Mk3 has always intrigued me.
I'm considering the Antitheses Fuzz too; I'd planned to build the Si version.