[RFI] RFI Clean Audio Amplifiers For Amateur Use?

[Rob Atkinson]

You're probably okay with any small 8 or 10 watt push pull mono tube
amp.  Look around for a vintage one that needs work.  These are simple
circuits that only need the usual restoration such as recapping and
cleaning pots, maybe replacing a tube and power cord.  you're less
likely to experience diode rectification of RF with a tube amp and the
output transformer isolates the speakers.  You may need bypass caps on
the input or a small isolation transformer.   I have a pair of
Heathkit SE3s in my station driving larger speakers (probably too much
power for small computer speakers) and all I had to do was loop the
audio cable in through a ferrite core a few times.  Oh yes, speaker
"cable" is two lines of copper AWG 14 solid THHN put in a drill chuck
and twisted.  That last trick is important.

73
Rob
K5UJ