Total posts : 45366
Thanks for your time and effort to run the numbers.
Discussions of range achieved by part15’ers on AM seldom mention the conditions at the receiving site. With Rich’s numbers, we can predict the open field performance which is probably most closely experienced in practice with a mobile receiver. Unfortunately, part15 broadcasts are not too useful for this mode since the listener will drive through the coverage area in minutes.
I don’t want to be discouraging by saying what follows, but it is what it is. It is not likely that at home listeners will have the field strength at their receivers as strong as predicted or as strong as would a mobile receiver. Add to that problem the difficulty with noise on AM from light dimmers, computers, flourescents, etc. and the situation for practical home listening gets worse.
Rich’s numbers show a rather limited range with ideal conditions. For reasons stated, the practical range is less.
There is nothing wrong with trying what you can to make a part15 AM system “serve a community”, but I wanted to point out what you are up against.
I, and I am sure others here, would be interested hearing from those who have an idea of their real home based listening range rather than a calculated contour. All I can offer is that the maximum home listening range I ever achieved years ago was about 700 feet (using a KnightKit broadcaster which probably exceeded the 100 mW limit, and a 10 foot antenna).