Buzzing when VCR connected to TV


I have a JVC S-VHS VCR hooked up to my Pre amp via audio cables and have the video connected to a Pioneer Elite Plasma. When the VCR is playing and the TV is on I get a pretty aggressive buzzing in the speakers. If i disconnect the video cable from the VCR to TV input , dead silence.
But if I use the coax TV out on VCR to B-Antenna In on TV the buzz is present but not as bad. Any ideas? Filters? Can't seem to get it gone.
theo

Showing 1 response by jea48

Theo,
Question is do you have a CATV cable connected to the TV?
If so disconnect the CATV cable from the TV or CATV cable box and see if the buzz/hum stops. If it does the problem is a ground loop caused by the CATV cable system grounding.

Is the sound your hear truly a buzz or is it a 60Hz hum?

If a ground loop hum problem.
When you connect the VRC to the TV you complete a current path from the CATV coax cable through the VCR to your audio system then on out your safety equipment ground to the electrical panel then on to earth. (A difference of potential, voltage, exists between the CATV coax cable ground and the safety equipment ground of your homes electrical system.)

If disconnecting the CATV coax cable from the TV does not stop the buzz then the problem could be high EMI/RFI emitting from the Plasma TV and entering through the video cable.