All HDTV tuners that I know of (at least ATSC ones, for North America) also support NTSC/analog tuning...also, there is no difference between regular antennas and "HDTV" ones...all OTA HDTV channels use either VHF or UHF frequencies, just like analog TV channels have for years. So if you plug in a single antenna (ideally, one that supports both VHF and UHF), you should pick up all available free/OTA HDTV and analog channels in your area...
You can check out antennaweb.org to find out more information about your local digital and analog stations, their locations and distances, etc...