Television Antenna & Reception

New on this forum, I have a 2007 model 2720. Love it so far. We've had one problem, hopefully someone can shed some light. I've tried to hook my small portable television to the antenna/coax connectors in side the trailer. When the center pin on the coax hits the inside of the barrell connector I have great reception. When the full cable is screwed on to the connection, reception is lousy. Has anyone else had this problem? What was the remedy? TV works fine on the radio shack antenna I have in the house. Is the cable to the antenna on the roof crimped and shorting due to the lift system? Any thoughts would be helpful.

Lost in picture snow!
Rob in Idaho