Ground loops can happen even in the most carefully planned A/V system. When ground loops happen in a video system, the result is unwanted hum or video hum bars.
In cable TV systems, the power supply for the cable system amplifiers is powered by a different source than the equipment that is used to enjoy the programming. The National Electrical Code requires the cable system to be bonded to the power service entrance ground, but in actual practice, this is not always the case. Even when the code is properly observed, there are other factors that can cause a difference in ground potential. It can be because one of the circuits is loaded more heavily than the other, or because one run is longer than the other, or any number of other reasons that are beyond the scope of this article.
The result of this difference in ground potential is commonly referred to as a ground loop.
Ancable Ground Loop Isolator is elegant in its simplicity. Just insert it anywhere in the RF line between the cable TV and your equipment.
Immediately, the effects of the ground loop become a non-issue. Problem solved. There are not too many things that one can install in an A/V system that can provide so much improvement with so little effort.
Tips: Don't Forget the Cables!
Good cables are very important in the fight against hum and noise. You will need at least one short patch cable in order to insert the isolator into your signal path. If your cable has too much loss, then maybe you need to consider upgrading your existing cable(s) as well.