I have sort of a unique GMRS antenna question.

[Charlie_V]

So point is make sure any gaps are pointed away from antennas and important cables.

This is the project board I keep mentioning. Pro tip I learned on the first use of a worklight: get a BUG LIGHT and fixture that does not get hot (LED light, plastic housing). My first foray yielded burnt fingers and a truck full of bugs.

Inverter mounted high so I can run cords with the back window open but the barn doors closed, to keep rain and dogs out. Please pardon my mess there.

So if I am reading the quote above correctly, something to close the gap between the lead edge of the solar panels and the roof would be ideal, since the PV wires are underneath and run to the rear. I have to think about how to do that because the roof arches slightly in the middle.

 

[PhulesAU]

You do realize that 5o+ watt antennas have been mounted that way for decades with no ill effects? anything above the Gigahertz level will be fine, as long as you are nt touching the radiating element.
LOS is a missleading term in this case. Unless you put the antenna right up agaist the body mass, or completely below the roof line you will notice very little signal loss . the major deadish zone should be directly behind your vehicle, and that can be mitigated by getting by heving as much as you can stand above the roof line.
1 other thing. I find having the antenna up there acts as a warning for low hanging obsticles.

 

[Charlie_V]

That last was sage advice. My best guess was to put the GMRS antenna in place of the cellular booster antenna. I decided to do that even as I had my drill hovering over the roof to drill a new hole with Larson 3/4 inch hole saw (I marked for a wide pattern, and the GMRS was going to go to the passenger side of the cellular booster antenna). Replacing the SMA terminated NMO cable with the correct PL259 NMO cable was easy. This way, the GMRS antenna is in the middle of the usable roof space. The GMRS antenna is also a little taller but has some flexibility whereas the high gain cellular antenna has zero flexibility. I ordered a lip mount for the higher frequency/lower power (5w if memory serves) cellular booster antenna. I put a stainless washer between the bottom of the new NMO and the inside of my roof for additional strength (13/16 ID and 2 inch OD).

I also ordered an SWR meter that hasn't arrived yet but initial testing is giving me astounding distance to an open GMRS repeater from our city home--24 miles at medium power (20w)! City home to country home is about 30 percent farther and country home is 250 feet higher, so we may or may not have surprising distance there, too.

Also, as to the very first few comments on the handhelds, I re ran our tests for distance at ground level in the woods and I cannot explain why, now, we have very good handheld to handheld comms everywhere on our country place and didn't before. We are almost totally wooded and the leaf and tree cover definitely hasn't diminished since we first tested, so something was wrong with our initial testing, I suppose. In fact, we still have good, clear comms from a starting point deep in the woods to at least a mile away from the farthest corner of our property. I am very impressed with GMRS over FRS or CB radios. These little things are amazing, simple to use, and fit our needs perfectly. The mobile radios will easily reach town and our only grocery store and three restaurants (four, if you count the grocery store deli, which i don't) approximately 6 miles from property, making up for spotty cell service. That's a real nice thing: to be able to call back from the store and ask "do we need this or that"--something I've taken for granted everywhere else for at least the last 20 years. Knowing that if one of us is hurt, stuck, needs other help, or bit by a snake and can reach the other even in a bad cellular spot is a even better.

The truth is that I am quite a bit older than I let on and we (wife and I) do worry about our physical health and safety--especially getting to emergency medical care if needed from the country place.

And being able to talk when we take two vehicles and hit any of the several low spots without cell service savea irritation and distraction redialing. Win, win, win.

Thanks to everyone for their attention and advice.