HD TV and dual dish receiver

[colesmom]

I just bought a Samsung 19" lcd hd tv for my bedroom and hooked it up (as the 2nd tv) to my dual dish receiver via coaxial cable. The picture quality is awful, which is ridiculous for how much I paid for the set. I finally understood that the Samsung won't get a great picture unless it is hooked up to the dual receiver via rca cables. (as told to me by the Dish chat rep)

Is there anything else I can do? I don't have an HD dish receiver b/c my downstairs tv isn't an HD - its an old tube.

Should I move the receiver box upstairs? Take the tv back and just get an enhanced def set for a much cheaper price? I don't have an off air antenna yet, but that won't help me with most of my dish channels.

Please advise!!