[Amps] Zener? question..

[Tom W8JI]

> Same dual 4-1000A g-g amplifier, different question. The 
> designer used a
> series string of diodes to provide grid voltage.
> Fifteen diodes marked "PTC 2050" I have been unable to 
> find any reference
> to these. I removed one and tested it like
> a zener, and never detected a breakdown voltage up to 35v, 
> that's where I
> stopped. Might someone recognize the part
> number. I would like to complete the documentation 
> accurately. Thanks.

Is the amp grounded-grid cathode-driven?

Does it have screen and bias supplies?

What's the HV?

Which way are the diodes pointed? Anode to positive source 
or cathode towards it?

73 Tom