[GreenKeys] 120VDC power supply noise?

[KC0NNC at aol.com]

Sounds like a Sola Transformer style of hook up.  The AC capacitor is  a 
resonating cap, and transformer and capacitor form a resonant circuit,  providing 
a relative stable output ac voltage to present to the  reci=tifiers.
 
I would be impressed if this bridge of diodes is really germanium, but if,  
so it really dates this circuit.
 
It is normal for a sola transformer circuit to vibrate, I have yet to see  
(or hear) one that didn't.
 
There are several tests one can perform, but just for kicks, unhook the  load 
(the diodes and DC capacitor, load resistor etc.) and run the circuit with  
out them, see if it (the transformer and resonating cap) still makes  noise.  
also, under these conditions, measure the ac voltage presented to  the input of 
the diode bridge.
 
I suppose it is possible that one of the diodes is shorted.
 
if you need more trouble shooting help, feel free to call me via toll free  
cell phone (weekend use all you want minutes, or email me)
 
73's
 
Harvey E.  Smith, KC0NNC
2020 Baculite Mesa Road
Pueblo, CO., 81001-2456

719  406 9735, 719 671 2671, 719 546  1418

zzzz/ryry