Again, I'm not saying you're doing anything wrong if you're getting the results you want. I think you're misunderstanding some basics and forgetting that correlation isn't causation which is causing you to do some unnecessary work or make some false assumptions. It feels like you still think the ground plane has something to do with electrical grounding. It doesn't. Or the discussion about having to bond the body to the frame (already done at the factory) and creating a ground plane because aluminum doesn't work as one (it does). Or that the galvanic corrosion caused RFI due to a "ground problem." The ground plane is only for transmitting, it has nothing to do with receiving and it has nothing to do with electrical grounding.First “galvanic corrosion”... it wasn’t improperly installed, I would say improper mount used... I used chrome mount and the supplied screws... not realizing they weren’t stainless steel... problems started arising after the corrosion was present. By the time I figured it out, I had to patch my roof... after lots of thought, I ended up getting a NGP antenna so I could glue my mount to the patch. I think I made it sound like it was a ground plane issue when it’s not... if you go read back to the Ford document you linked, fasteners need to be aluminum or plastic... hence used a plastic boat mount and a NGP antenna because bonding the connector back to the roof was going to make matters worse.
next you mention power source... I’m running 8” of 4 gauge wire between my power supply and radio... and 12” of wire between power supply and battery. I’m running 12 turns of both the positive and negative wires through separate T240-43 toroid. 1/2” ground strap bonds my radios, atu, and power supply to a common ground bus. From the ground bus I am running 000 welding cable to a grounding Rod array of three 8’ grounding rods buried 6’ deep bonded with the same 1/2” grounding strap.
Now back to the RFI issue... it was a two fold broblem as well.. first the galvanic corrosion caused a bad grounding connection which made The antenna more susceptible to RFI interference... second problem was once the corrosion started it ate its way back along lines under the roof where the electrical wires and coax cables ran (probably more due to water leaking than due to electrical problems.
So my solution to all these problems was very simple... use a piece of plastic to isolate the antenna mount away from the aluminum, glue the plastic and rivet using aluminum buck rivets, and use a NGP J-pole antenna. All of this is documented very well in my hamshack thread.
btw... I must be doing something wrong... I made a 2 meter voice contact last week at 110 miles at 10 watts with a 5200 foot mountain between us.
Do what works best for you and your vehicles. Just trying to clear up some misconceptions about ground planes vs electrical grounds and what works as a ground plane. The antenna size (1/4 wavelength, 1/2 wavelength) also determines if a ground plane is needed or not. Don't mistake not needing a ground plane with it being a NGP antenna. They are two different things.
Sorry to be pedantic, I just don't want people to go around thinking a ground plane has anything to do with electrical grounding or RFI. Totally unrelated.
Anyway, not here to argue or talk in circles, I was just trying to clear up what appeared to be some misunderstandings. Take care!