This has been brought up before either on part 15. Org or some other part 15 site and it just occurred to me when one of my listeners brought it up. The idea was to run a second transmitter on a boat that is dry docked and still in the water whereas the ground lead would be in the water and connected to an 8-foot ground rod or some type of ground rod to hold it in. The signal would be from my internet stream picked up by a tablet or smartphone ran into an audio processor and into the transmitter on the boat. Now Stingray Point Marina is about two miles away from the Deltaville Market. Therefore when my signal would fade the second signal would come up which is about two miles away. And at a mile and a quarter my signal is pretty weak so I'm thinking that the marina would be perfect as there are a lot of folks in that area there is a campground near the area to and being that Springtime is coming that might be the perfect way to get a second audience.
The idea is that water carries electricity or should I say conducts electricity very well so I'm hoping this would cause the transmitter to have some good range. Any thoughts?
They say saltwater is about the best grounding for a transmitter you can get. A few years ago I experimented sporadically over the course of a month or two with the Rangemaster mounted in my sailboat anchored in the back river. The transmitter was mounted at the rear of my cockpit (about thigh high) with a copper wire running out a transom hole and simply dangling a few feet under the saltwater. I wasn't really able to give the experiments full attention as I was working full shifts everyday and really didn't have the time to get in my inflatable to go back and forth to the boat as much as I would have liked to, nor was I enthused about leaving the transmitter on an unattended and unwatched sailboat, so most of the experiments were only an hour or two at a time before it got dark, but I did leave it there transmitting constantly for about a week or so once.
My sailboat at the time had a simple solar setup; a 15w Renogy solar panel, a cheap charge controller, and one 12v deep cycle battery I had bought from WalMart for about $100. That is what powered everything. For my audio source I sometimes brought an old laptop with Zara, and other times just used my tablet with some random MP3 player. I didn't use any processing gear (although planned too for the permanent install). Once I left it there transmitting constantly for about a week - ten days- whatever it was, that was when I was best able to observe it's increase in range...
I don't drive much anymore and don't even have a car, so most of my test were simply done by walking or riding the bike. I used two pocket portables: a Sony SRF-59 and RadioShack 1200586 - These are the radios that Radio Jay Allen rates as the top performers in AM in the "pocket radio" category. The Sony seemed to slightly perform better in reception and distance, but I kind of attribute that to the fact you have to use headphones with it, whereas the RadioShack has a nice sounding built in speaker.. For the most part they performed the same.
Anyway, this is what I noticed about this install.. But you also have to keep in mind that I was comparing it to my usual elevated install in the same area but on land, and having no ground at all attached to the lead.. however I have had grounded installs too, so I'm not comparing blindly.. Anyway, yes, there was definitely an notable increase in range, but the problem was it didn't go where I wanted it to go! It did great along the back river and about one block in from it along a parallel road, and in some sporadic spots even over a mile away (listening only my pocket transistor radio).. but not inland farther than about a block... It really seemed like my range was more due to the wide open area of the river than anything else, and it was along the river that my range was increased - but not inland.
Transmitter on a boat is a great way to go about it, but only if your target audience are the houses and marinas along the banks, and/or the boaters out in the water. I think that's the only way a legal 3 meter install on a boat is of advantage.. because it didn't really seem to go inland towards my target area only blocks away. So, as with any installation it's best bet is to install the transmitter in the actual area you want to be covered.. The extra range the seawater gives proved moot for my situation, but I could see utilizing it for broadcast on a different frequency specifically for the back river.
Don't know if that helped you much, but that was my experiments and conclusion.