I once thought of putting up an invisible HF dipole right on the top
of the popup top on my Westy. I had some 1/4" wide copper tape with
adhesive backing. I could tape the copper tape on the popup top in
a dipole or inverted V or whatever shape for CB, Ham radio, regular
AM/FM radio or even TV. Such an antenna will work better when the
popup top is raised up. I just have not given it a priority among
many things to do yet.

David