Bill Horne wrote:

* Can I get by with an old VHF-UHF combination antenna?

My advice would be to try it and see. You'll know right away, as
digital reception tends to be pretty much "all or nothing". I had no
problem with my existing antenna when converting to the new signals.

If it ain't broke, don't fix it.

If it is broke, then do a little research to determine what frequencies
you're interested in (VHF, UHF, or both) and how far you are from the
transmitting locations. There are web sites that will help with that.
Given that information, you'll be in a better position to figure out
what you need.

73, Steve KB9X