I have a TivoHD unit in a spare bedroom, and have it paired to Comcast (Xfinity) for cable. I was thinking of adding it to my main viewing room with my Premier XL4, but hooking up a TV antenna to it for some of the local subchannels. Its been so long since Ive changed anything I have a couple questions: 1: Can I tune cable and antenna at the same time with the TivoHD, or just one or the other like the base Roamio? 2: If I can tune either antenna or cable, will rerunning guided setup to add in the antenna cause me to lose the pairing on the cablecard? 3: If I cannot tune both at the same time, will rerunning guided setup to switch from cable to antenna erase the pairing on the cablecard should I want to switch back to the cable? Sorry for the dumb questions, but between DirecTv and the newer Tivos, Ive totally forgotten about the TivoHD.