Another crazy problem... any ideas?"
The Faraday cage is a good idea, but the equipment casings, so long as they are metal, is a good enough shield. The trouble is in the wiring, almost certainly.
Maybe you could use quad RG6 in conjunction with the ferrite devices? You could try not terminating the outer shield of the RG6?
The Yamaha is likely a hot chassis, but I don't know about the VCR. Maybe you could use the center conductor in the RG6 cable without anything else connected and run a separate RG6 center conductor under a screw on both devices? If the chassis are not hot on either/both device(s), you could connect the center conductor from the RG6 to an obvious ground on one of the circuit boards (after the power supply primary.)You could add the ferrite thingies too.
I'm no expert on this sort of problem, but that is what I'd try.
Another problem... any crazy ideas?
Dispose of the radio station:
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