There is one important point you are missing. If, during your test out on the pavillion, you had a three meter whip
right at the transmitter, a short ground wire to the pavillion as I described before, it WOULD be legal.
And it would work just about as well as the test where you made your connection "up higher" on this grounded structure.
As a massive grounded structure, it would be irrellevant that some of your "ground" current doesn't go
straight down into the ground, but has some circulation throughout the whole structure/circuit.
This creates a field but the more important part is that the whole thing is well grounded over a large area.
The local fields would be contorted by distributed current flow in the structure but as distance
increases the rf field will be more unified. And so much better than if the grounding weren't so effective.
Never really comprehending the physics of Am radio waves, Your anology of the pebble dropped in the water does make it considerably clearing to me that the AM waves travel ground and are not an airborne creature.
I've heard it said before, but not in that way, and I think I comprehend the concept more than ever before.
But Tom, as for your indications that my previous install tying into the ground system of the pavilion was actually legal.. well, I've pondered about that several times today after reading your post, and frankly I don't see how that could be true.
The roof of the pavilion is in the shape of a huge octagon, and at each "seam" run the large copper cables which all meet at the pinnacle of the roof, with the other ends all extending down and deep into the sand at all sides only a few feet from the Atlantic ocean.
I had my transmitter imeadiatly above the pinnacle and connected to the cable system with about a 4 inch piece of wire.
Therefore by definition of this setup my antenna system consisted of a 102" whip and a very massive, heavy duty elevated radial system. I can not fathom how anyone
could look at that and consider it a legal part15 installation.
Having an obviously grounded ground rod next to the building just outside the window would be ideal.
Is there some bare soil right there by the window?
Set the transmitter by the window, minimum wire out the window straight down to the rod.
Another wire or short as possible coax out the window to the intended radiator, which need not be at ground level,
but could be mounted in an insulated way, part-way up the side of the building.
Avoid being too close to the incoming AC service (and the vertical conduit which would sap signal as R Fry reminds).
There is absolutely no dirt anywhere near the window or the front of the building, the only window isn't the kind that opens anyway, but a solid sheet store front type window. The closest dirt is in the narrow ally between, and about 15 feet back from the front. The office is tiny, only about 16' square or so, with one door and a small window unit air conditioner embedded in the concrete on the alley side wall. There's not even a bathroom.
Even if I did find a way to put the transmitter inside, it would probably reek havoc with the wireless digital phones and fax in the office, as well as screw with the tv reception.. I don't know if the 5' foot high steel safe would have any effect on absorbing the radio signal or not..
But it's all besides the point.. I doubt having my transmitter inside the building would be the best option, and although I'm quite naive about radio engineering, I will continue to consider it the worst possible solution, until proved otherwise.
I appreciate the discussion, but the idea still sounds ridiculous to me.