This is a post for general reference for anyone interested in installing a cellular booster in their Airstream travel trailer but might be unsure of where to begin. For most of us, the big concern is drilling a hole in the roof and not creating future leak nightmare and/or accidentally hitting some hidden wire, support, etc. What follows is what we did on our 2016 Flying Cloud 25FB. YMMV
There are many options to choose from in considering a cellular booster and this post isn't meant to be a study of what to buy but of how we installed it. Prior positive experience predisposed us to select the weBoost line from Wilson Amplifiers. In specific, we chose the Drive X OTR Fleet Signal Booster Kit for the travel trailer because by mounting the antenna on the roof, we felt that the height and the metal plane of the roof would give us results equal to what the more expensive Drive Reach version would provide. For the F250, the Drive Reach was used because the antenna was mounted much lower, just over the driver side fender.
We do our own maintenance and upgrades whenever practicable because when you get stuck at a campground with a burnt-out hot water heater ignition board, or the thermostat wire to the heat pup is grounding out, its more comforting to us to be able to fix the problem ourselves instead of being reliant on others to help us at a time and place of their choosing. That said, when the large drivers side window shattered, it was Dallas Airstream who put it all back together again because for some things, there is no substitute for kind, knowledgeable dealer repair expertise. I point this out only to give you a reference point to whether or not the information posted here is worth paying attention to. For example, we did our own 450w solar installation among other projects.
In our unit, the best place to bring the wire down from the roof was through the closet adjacent to the shower. We knew from taking apart the light fixture and poking around with a light through the return duct vent in the main hall that there were no wires or systems we would accidentally cut if we drilled through the closet. We drilled up from inside the closet through the roof using a 3/8" metal drill bit. This size was chosen because it fit the 3/8" rubber grommet that we used to protect the RG6 wilson cable from chafing against the cut metal. Anytime we wire through a moving object, we use a simple grommet like you see in the photo below.
To completely seal the roof penetration while giving future ability to change the cable should it get damaged or to simply upgrade the system in the future, we used a Scanstrut DS21A-S stainless steel cable seal with rubber compression cable glands. The benefit of this method is we have a metal fitting that won't break down under UV rays or otherwise get compromised mechanically while having a UV stable weatherproof seal around the cable that can be easily removed and replaced in the future. A grommet was inserted into the roof hole, the Scanstrut then slid onto the cable and the cable itself was passed through the roof grommet into the closet area below. The base of the ScanStrut was screwed into the roof of the Airstream using the provided screws. Excess cable was tied to the roof using a cable mount with 3M VHB. Once the interior cable was secured inside and attached to the Wilson Amplifier, Sikafkex 291 Fast Cure Marine Adhesive was squirted inside the ScanStrut above the grommet and then around the exterior of the ScanStrut between the stainless steel housing of the cable seal and the Airstream white aluminum roof. The ScanStrut was then mechanically brought under pressure using the 3 screws provided thus sealing the rubber of the gland around the cable.
The hard part having been completed, we routed the cable over the top of the shower and installed the weBoost amplifier on the wall just above the TV taking advantage of the proximity to the electrical outlet. We have both 12v
and 120v adapters for the booster so we can run it while plugged into shore power and while boondocking which is how it is usually used.
Hopefully this helps the next person thinking about this install.