Ground Loop Humm/Buzz from Television


Any suggestions on the following: I have noticed a humm/buzz in my speakers that I suspect is some kind of ground loop. However, it appears ONLY when the television itself is on and disappears when I turn it off. I tried lifting the ground on the tv (which, by the way, is tied to a properly ground satellite cable/box) but to no avail. I haven't found any precedent in any of the archives so any thoughts out there?

If you are connected to a coax cable TV feed, it is likely that the cable is causing the issue. This is VERY common and has been widely acknowledged on this and other forums. You can purchase an in line isolation unit that will solve this issue. I know there is one made by Mondial and I have read that Radio Shack sells a similar unit. I think the Mondial sells for about $99 new. Here's a link to an A-goN ad for a used one. BTW, I'm not associated with the seller.

I hope this helps.

Hi ReubenT:

Thanks for the response but if you had read the entirety of my post, you would have noted that it is NOT a cable tv connection. It is a properly ground satellite connection. Indeed, when I had cable many moons ago, I used the mondial unit and it was not helpful. Trust me, I took quite some time to search the various archives and I found nothing similar to my post. Nevertheless, thank you for responding.

I am beginning to wonder whether there is a shielding issue with my tv (it is about 10 years old) and it is throwing off a lot of something . . .

A TV can generate a LOT of electro-magnetic garbage that could be picked up by your other equipment. It may not be easy to do but putting some distance between the TV and the rest of your stuff, at least temporarily, would tell you. Good excuse to go out get a new plasma TV!
This may or may not help, but I'll relay a similar experience. I had a buzz when the tv was on, regardless of where it was plugged in and the grounding status of the tv (it is 12 yrs old and connected through coax cable tv, and located 0.3-4 m from my audio gear). After changing the location of my various audio components to different shelves, it vanished. I never did figure out whether it was the change in distance of one or more components from the tv or simply plugging and unplugging IC's that solved the problem. Possibly, removing the IC's may have abraded and/or "cleaned" them, or the amp or some other component was moved out of a critical EM field. This may be irrelevant to your case, but might be worth a try in case there is an EM field or RF that is the underlying cause.
watch out some plasma screens cause all sorts of interference problems.. good luck with your cordless phone.
You might try grounding the case of the satellite receiver to the electrical ground of the house. I used a wire with spades on both ends, and connected from the satellite receiver to the ground on the electical wall plate. I do not know if this will solve your problem, but it is an easy solution to try.

Jim T
Just a guess, but, maybe your properly grounded satellite is one ground too many. Forgive me if you already know this, but, you should have an odd number of ground connections. Perhaps a cheater plug on your satellite/cable box might be the trick. Good luck.
Thank you everyone for your responses but I actually think I may have a more serious problem. In doing a little experimenting today, I noticed that every time I plugged the power cable from the tv into an outlet, a little spark jumped from the connection. Bad news, me thinks.