PNPs - a few on the hang cards.

[MKULTRA]

Does anyone have any experience using either of these types?

[duck_arse]

there is a circuit called "controllable tremolo circuit", I think from the heilmann collection, that uses a hep251.

this doesn't really help you, but at least it means "the part number" won't nag me anymore as to where I had seen it.

[Blitz Krieg]

heilmann collection, that uses a hep251.

sorry, but I couldn't find anything in the searches.  do you have a link please?

[italianguy63]

Helped you out Ducky!

Equivilents for the HEP251 and HEP801 are ECG102A and ECG312 respectively.

MC

[duck_arse]

thanks, itg63.

apropos of nowt, someone here was shopping a load of "HEP-something" fets, don't remember the number or the who. another something to nag me.

apropos of something, that circuit has positive supply, 18V supply, caps w/ (+) grounded, and pnp bjt. caution required!

[italianguy63]

Sounds like a cool project for a charge-pump inverter/doubler... 

[Luke51411]

Sounds like a cool project for a charge-pump inverter/doubler... 

I wonder where someone would be able to find something like that?

[italianguy63]

Mine doesn't double.. but I don't remember that being too hard to do.  The text says it needs input and output buffers too...

[Luke51411]

Mine doesn't double.. but I don't remember that being too hard to do.  The text says it needs input and output buffers too...

Yeah doubling is pretty simple, I think it's just a matter of a couple caps and a couple diodes with the doubler IC.

[italianguy63]

OK-- that poses the question?  

Has anybody done voltage doubling AND inverting with a single charge pump IC.  i.e. +9V in and -18V out?

[MKULTRA]

Equivilent for the HEP251 is ECG102A.

MC

Fixed.

Therein is the problem.
The ECG102A covers a wide range but surely does not reflect the characteristics of the NOS part on hand.
Nor will it have the same potential for something other than else. A simple, PNP germanium fuzz should not be out of the question.

All help is appreciated.