I have cable TV with a box in the living room to get the premium channels and just basic cable in the other three bedrooms. I just put another TV in the basement. I went to Radio Shack and purchased an AB switch thinking that if I hooked it up to a TV in one of the guest rooms that hardly gets used to the one in the basement that I could watch basic cable down there. However, I couldn't get it to work. It think it is just for hooking up a TV to a VCR. Someone told me to use a splitter but isn't that illegal? I'm sure if I called up Comcast and asked them they would say it was so they could come out and charge me for doing the work. How can I find out if this is legal to do and if it is, how would I go about installing it?