I have a 2006 Mallard CK180 trailer and would like to install a TV antenna. It has a coax cable terminal on the roof and a coax terminal mounted on the ceiling above the TV shelve with a built in amp ...
Google non directional tv antenna and you'll get a variety of hits. The round non directional type could be attached to the roof with 3M VHB tape and you might need a larger base for mounting. I would get the amplified version.
I have a amplified flat wave antenna attached to a window on the inside. It's bidirectional but otherwise works well. Just another option.