[Amps] 6m amp based on W1QWJ

[Paul Decker]

Hi gents, 



Thanks for the HV responses, great advice. 



So I'm embarking on a reproduction of W1QWJ (sk) 6m amplifier using a 3cx800A7, it's in the 1995 ARRL handbook.    This will be my first full up homebrew tube amp.  As a general question, is anyone familiar with this design?  Has anyone reproduced something similar?   



More specifically, I'm looking at the filament section and there are two caps marked .001/500v F.T. but they have three legs, one connected to the filament, one to the filament xfmr, and the other to ground.   I assume these are .001 uF Feed Through caps?   What is the purpose of these?   Why 500v, that seems extreme for a 13v filament voltage.   Also, I see the filament is AC, any reason?   I was thinking about using the filament xfmr to power other portions of the control circuit, but I would need DC to do that.   Do you see any issues in straping on a rectifier in parallel while still powering the tube with AC? 





Thanks for the help. 



Paul, kg7hf