I bought a Samsung DLP with a built-in HDTV tuner. I put an OTA antenna on my roof and pointed it at the sears tower (I'm lucky - it's 13 miles away, no need to guess what direction to point, and line-of-site.) I then used existing cable tv wiring to wire the OTA feed to the back of my TV. Everything works great - I get 80%-100% reception.
I know you can use a diplexer for satellite/ota-hd mux/demuxing. Can you do the same thing for cable/ota-hd or do you need 2 seperate coax cables? There are 2 coax jacks in the back of my tv, air and cable, and I'd like to demux the OTA line and the Comcast Cable line in the basement, then mux it back to separate lines behind my tv to avoid drilling more holes. Is this possible?