Total posts : 45366
Frank, in the post above, has given a link to a system using multiple transmitters to cover a “town”.
My post referenced a single transmitter and perhaps that was not clear.
Now you have something to consider given the range of a single transmitter versus multiple transmitters. There have been posts here previously where the problems of co-channel transmitters including audio and RF phasing considerations have been presented. You might do a search for these so you will know what is involved.
You might also consider the population density and electrical interference in your proposed “service area”. Maybe you could go on the air with a unit such as the SSTRAN with the antenna described on their site or use a Rangemaster and get some idea of your coverage.
Keep in mind that mobile reception is usually better than in home reception due to the reduced electrical interference and higher receiver sensitivity as compared to a typical home AM radio. For example, I can hear a usable signal from my transmitter about .2 miles away mobile, but can barely hear it 200 feet away with a cheap portable radio. To be fair, I mention that I am not using an outdoor antenna to transmit, but the comparison between receiver quality is still evident.
Hope this helps.