Total posts : 45366
Spreading your transmitters around town whether they are synced or not seems like a safer alternative to clustering several transmitters in close proximity to boost the signal.
5 transmitters feeding one antenna or each its own, I would think the Inspector would feel you are pushing the intent of the Part 15 rule by purposely exceeding a calculated norm under Part 15.219. I don’t think you can even get away with inductively feeding a tower by placing the 10 foot antenna in close proximity to take advantage of reradiation.
By the way, there is an old publication I’ve seen that addresses the idea of repeaters interconnected with coax. Somewhere around here I have the schematic for that if anyone is interested.