Total posts : 45366
I haven’t tried the NEC calculator, but I can say one thing for absolute sure: My antenna being on a boat in a marina, grounded to the sea, gets out great compared to any I’ve experimented with at my studio with poor ground.
Some additional notes are that literally everything in the intended listening area is above the antenna, and except for the streets, is virtually all buildings … then also, sometimes the signal travels out into the valley quite a ways, and has been heard up to 3 miles away. With hills and buildings in the way at 1/2 mile or better, the signal gets noisy, but as soon as the valley opens up, it gets better then fades out sort of slowly.
A few blocks from my studio on a street that angles out away from town, there is some interference over an actual rise, but as I go back down on the other side, which is of course further away, the signal gets better. On another road that turns off, fairly close to the water, but yet with a hill in the way, the signal is quite good. I can’t come up with a terrain explanation, so maybe there is some sort of strange counterpoise thing, perhaps with the proximity to open water.
Overall, I’m saying the signal does very well close to the ground, i.e., in the horizontal, even with buildings in the way (driving up an alley seems to make little difference), with the exception that getting close to one with a lot of florescent or neon lights does me in. Vertical height did make some difference … I added 4 ft. I tried with another 8 ft. mast extension (which required re-tuning), but it didn’t do nearly as well as the in-between one, which is lower.
Of course, as night falls, everything gets worse until sometime around midnight, when for some reason it begins to get a little better.
Antennas and propagation is indeed physics, but there are apparently so many variables that it’s nearly impossible to factor everything in, and so their real-world operation becomes extremely critical at these puny power levels. I find my signal varies in some small way each day, but I’d really just be guessing as to what’s causing it.
It still comes down to a lot of experimentation … which is what we do, yes? There’s some sort of inner glow of excitement (endorphins?) that come when some crazy experiment pays off. I can’t explain that either, but It seems to have me hooked 😉