[SCCC] SB-220 Re-Build

[Jim McCook]

Joe,  In 1975 W6FR wrote a excellent article for a VOX bias circuit that 
didn't create the switching noise that is so characteristic of some 
older amps such as the Alpha 77.  He worked out a few improvements and I 
built the final circuit, which I used with a pair of 3-500z for years.  
Nobody ever was able to hear the switching sound.  The difference in 
exhaust temperature was substantial with this board switched in.  I sent 
the schematic to your Email address, since it wasn't accepted here.  Jim 
W6YA