I just bought a Sony HDTV. I have a HD package through my cable company but it does not offer CBS in HD. I think I need an over the air antennae to receive this. I might be wrong. Can someone help me out here and let me know if I need an antennae and where a good place to buy one is? Can you also give me tips on hooking it up. I never seen or dealt with an over the air antennae. Any help is appreciated. Thanks. I am in the Johnstown, PA area. Southwestern PA>