I'm real new at this stuff, so be easy with the terminology. I want to connect an off air antenna to my dish 500 but don't want to run new coax cables to my receiver. I tried one that wraps around the dish and the instructions were pretty simple and I successfully hooked it up. But I'm not getting all the channels available, the ones that do come in are pretty good. How do I hook up one of those directional antennas (like that terk hdtvo) to the dish 500? Or can't I?