portable sat antenna don't need to be 'mounted' and wired to the roof, though some do that... it's probably easier and less expensive to just carry it yourself, and put it out on the ground when you arrive - since you can't watch it while driving anyway.
Ours rides on the rear of the roof, at the ladder area, with a temporary 'mount', and sometimes we leave it there if the satellites are in view from where we park, but most of the time I have to move it somewhere else on the roof, or mostly down somewhere on the ground around the coach. I just leave 50' of coax cable attached to it, and the cabling runs down over the edge, into the top corner of the slide, and to my Receiver. The extra cable is wrapped around the air conditioner cowling... works great... and easy.
'14 Thor Palazzo 33.3 compact diesel 100k+miles since '14... US, Alaska, Canada...
AND a '14 Gulfstream Amerlite
AND a '07 ForestRIver Rockwood