I don't even know the difference.
If the TV has an ATSC tuner built-in you should be able to watch the digital version of the TV stations in your local area using an antenna.
ATSC tuner - I don't know what that is either. I don't have an antenna outside my house. I do have cable service though.
I'm ashamed to be so ignorant of this stuff and the termonology.
I don't even care to have one because I watch very little tv , it's a gift for my wife, who doesn't watch a lot anyway but I've heard her say that it would be nice to have one and Christmas is coming.......
Hold tight, graybeard. Ratty’s yer guy.
An ATSC tuner means it can pick up over-the-air digital signals on the new digital standard. The old analog is NTSC, which will be phased out in 2009. So ATSC means it's "modern" and compatible with current and upcoming digital signals.
I don't know what cable service you have, but I'm going to assume that they offer "digital" service, and also carry HD channels. If you only subscribe to the basic analog cable channels, you may be able to get the digital versions of your local stations without a change in service. Otherwise, you will need to upgrade to digital cable, and possibly change your cable tuner to be able to get the appropriate channels.
Might have some more ideas tomorrow... but I don't know anything about your current situation and cable service.