[mythtv-users] Hum on analog audio to TV

David Brodbeck gull at gull.us
Sun Nov 2 00:46:35 UTC 2008


Scott Alfter wrote:
> (If you have one (I have a couple), put a polarized plug on it and make sure
> the chassis side is connected to neutral (a continuity tester between the
> chassis and the wide blade should light up/buzz/whatever).  This should
> somewhat mitigate the shock hazard that the AA5 circuit can pose.)

This works *if* the power switch is wired to the side of the cord that
isn't connected to the chassis.  If it's not, the chassis will still be
hot when the switch is off, unless you rewire the power switch.

Unfortunately, the switch being on the chassis side is pretty common.
It saved them a few cents per radio in wire and also slightly reduced
the amount of hum coupled to the volume control by the power switch.



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