[Boatanchors] OT: A question about using an 'audio mixer' in a ham set-up

[Rob Atkinson]

Little mixers are fine for routing receiver audio to amplifiers
driving speakers.   one thing to watch out for is mixers run off
switching supplies.  If you get one like that, run it off a linear
supply because switching supplies can allow your RF to get into the
audio.   I guess maybe if you run the switching supply off an
isolation transformer that will work.  You need that inductive
coupling barrier provided by a regular 60 cycle transformer to keep RF
on the power line from getting into the mixer.

Rob
K5UJ