[BC] RE: WMOXThump

[harold stanton]

Dave,
You are correct, the thyratron supply was one of the only designs I found 
that gave that "thump" at carrier on. The old RCA board that was there was 
all tube type and was never turned off.
  GE made a similar supply but I don't know of any of those that made it 
into the MW band.
The thyratron supply was a rather short lived incarnation of three phase 
rectification as I suppose that after a few rounds of trouble-shooting and 
improvements in the mercury vapor rectifiers for inverse standoff that 
"design" drifted into oblivion.
Willie, the "thump" did not originate in the audio chain, as many times I 
brought it up with the audio patched out. And it was far more prevalent on 
low voltage as the transmitter was configured as 1-10kw. On low power the 
thyratrons triggering time was staggered somewhat as a switching supply is 
now.