Back in the day I had Directv .Don't even get me started on my experience with Echostar(Charlie Ergen's Dish Network), are they even still in business with all the BBB complaints!!?
I've never seen a dedicated Dish connection on the roof, only on the side wall for cable or dish antenna. You could replace the roof mounted antenna with the Dish antenna but would likely need to rewire the coax cable as most use splitters and amplifiers to have a connection in the bedroom and living area.
I had the tripod and portable single LNBF round dish. My Aunt and Uncle had the crank up dish on their TT. With the way Directv and Dish Network were changing their dish/lnbf combinations every other month, a permanent crank up dish seemed like a bad idea to me.
I always camp in State Parks, so most of the time a Dish would have little use with all the trees. Also kids, rude adults, and even rude state park employees see it fitting to walk through my campsite often. Not sure I'd like the idea of them hitting/bumping into the dish antenna or tripping on the coax cable. Last time I went camping, idiot park employee was cutting the grass in my site while I had my stuff in the grass. Almost ran over my septic hose and water hose. She damaged my neighbors $500K motor home by throwing rocks all over it's side wall and leaving about 11 spots of chipped paint. He was still fighting with them when I left.
Directv quality and customer service went down hill with prices sky rocketing and programming choices stagnant, it was a no brainer to go to Comcast/Infinity when they went to digital programming.
I now have Comcast Infinity phone, 120 Mbps Internet, and all the cable premium channels CHEAPER than DirectTV's basic programming, At&t's 3.0 Mbps internet(Best Uverse speed available :R), and At&t's phone service.
If I wanted Direct TV for the Camper, I'd buy the cheapest portable dish that got the programming I wanted. That way when they add or change their satellite arrangement, it's much easier to replace the dish antenna.
I personally use the local digital channels from my TT's roof mounted antenna along with Netflix or Hulu for other programming. I use a Roku device with Verizon-wireless Hotspot built into my Phone. I also use the Roku for my home town local news coverage when I'm away.
Good luck, a lot of choices out there.
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