[W9WLS]

Several years ago, Collins Radio manufactured a hf antenna designed for intercontinental aircraft .

This antenna was 13'5" long and stood off the belly of the aircraft 8.5" and was fed by a tuner also made by Collins as was the Transceiver.

System worked pretty well for the most part , and I don't see any good reason something like this would not work on top of a motor home , would be interesting to try.

Also many years ago, I made a "luggage rack" loop type antenna on top of a friend's "cab-over" camper which loaded 40 - 6 quite well ( have the dimensions here somewhere ).