Can anyone help me with this problem? I have Sky installed in main living room with a feedback cable to attic so that sky can be watched in two rooms upstairs. I bought a skybol for each room upstairs which allows me to change the sky channel from the TVs upstairs. To cut a long story short, I have a sub in my main room which gave off a loud humming sound! I took the sub back thinking it was faulty! The sub was not faulty so I eventually discovered that when I took the co-ax cable out of the TV in bedroom 2 the humming stopped. I have since found out that the problem is down to a bad earth. Everything works fine in bedroom 1. I have taken the coax cable in bedroom 2 and removed the outer copper wire so that only the centre copper wire is entering the TV. This solves the humming problem in the sub. However, the problem now is that I cannot change the Sky channel from bedroom 2 as the skybol uses the outer copper wire to change the channel. I know it is a bad earth problem, but can anyone give me ideas of what to check, change or test? Thanks.