I've done it several times. To cover the hole for the coax wire, I bought a piece of roof flashing from Home Depot and screwed it to the roof covering the hole. Then I applied a coat of Dicor roof sealant. For the screw holes, I also applied Dicor.
[SIGPIC][/SIGPIC]2016 Newmar Dutch Star 4369
Newmar Owners Club
USAF 1966-1969,- Law Enforcement 1969 - 2003, Retired since March 2003