I want to use an OTA HD antenna...

Its hard to believe that Wayne Fontes is actually fondly remembered.
Perhaps they can bring Barry Sanders out of retirement.

Would Mr. Ford care for a Gruden & Allen duet?

They can be had... they've been had for most of the past six seasons.

I used to have a Channel Master with AMP back in the day before Cable & Satelite broadcasted the local channels in HD; best HD picture I have seen was with my OTA antenna. Blew away both cable and Direct TV. It's in storage now as the locals are now included and live in an HOA - too many antennas up there already. With the new MPEG 4 with direct TV, picture appears almost as good as the OTA (assuming I remember correctly).

I have a standard definition DISH network DVR on my Panasonic Plasma. The channels I watch most are not HD, so can't justify paying to change the DISH and receiver and paying more per month! I would like to also have over the air HD local channels by using an antenna. Can I just plug the coax from a roof antenna into the back of the TV and use a difference source (TV 2) or do I need to do something else? I see talk of amplifiers and splitters and other stuff. What do I need to do exactly? I am about 20 miles from town.

Your TV needs an HD decoder for the cable coax/splitter technique to work.

If your Panasonic Plasma has a built in HD decoder, then try connecting your DISH coax feed directly into a different source input on your TV and see what happens.

If it works, then you can use the coax/splitter technique for your TV.