Ok, I have an OTA antenna, which I am using in conjunction with my Dish Network system. But I also have basic cable from comcast, which provides unencrypted HD QAM feeds. I want to be able to add the QAM feed to my primary HDTV. My thought was to see if I could diplex the coax run that currently is limited to the OTA antenna. Is that possible? Can I combine the comcast and OTA antenna using a diplexer, and then just split it out again at the tv, one going to Dish's Antenna IN, and the other going to the antenna in on the tv?