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Re: Conductive paint



Hi Roy

Your RFI problem brings back a long lost memory .   Especially when you
begin wrappng your box in copper screen.     When TV first came out  (
are you that old? ) it had 20 mHz IF's and everything but the kitchen
sink caused RFI to that system.      Needless to say everybody tried
anything to get around that RFI.     The cure was to forced  industry to
move the 20 mHz IF to a 40 mHz IF system.        One of the things I
tried was your copper screen .    Solder was not near as expensive in the
40's as it is today.         A new earth ground with a short hook up wire
and it was no where near capable of shielding that TV IF system.     So
before I would begin the copper screen treatment I'd suggest that you
parallel .001 and .01 disk caps as close to the output of amp as you can
get without killing the audio.       Make the leads as short as possible 
.       If that don't help the problem,   it is possible that the RFI 
entry is earlier in the circuit than the output of the final amp.     
Try things that kill the audio ahead of the amp to see if it also kills
the RFI at the same time.    That should tell you which way to go.
Listening for results

Joe  K0VTY




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