bobbehr, did I see the word Terk in your post? Please use the search engine and put that word in, you will find vast amounts of expletives associated with that word. Don't waste your money. Buy a good brand name antenna and you won't be sorry.
Out your way you are dealing with both VHF and UHF, which we don't have to deal with on this side of the state, but from my years of experience if I was doing a setup in your area I'd opt for separate VHF and UHF antennas. Combo units often are a compromise. You may be able to get by just adding a Channel Master UHF antenna to what you have, if I was on a budget that's the route I'd take. The CM 8 bay bow tie has similar performance to my Televes, which I love. most of the discussions focus on UHF, you may have to do some digging to find a great VHF antenna, I'm still using my old CM Quantum 1160 from years ago for VHF and it preforms quite well, it's really lacking in the UHF range. You will defiantly want a rotor, and a great preamp, the CM 77xx series is everyone'e favorite.
good luck on your venture into HD.
Edit: seems to be a few threads on this topic, did you see this one?http://www.avsforum.com/avs-vb/showt...hreadid=405506