Total posts : 45366
[quote=mlr]If you try to link multiple tx’s across a plain old internet link, and those tx’s are close enough to cross signals, you will get a bad case of heterodyne. You have to somehow synch them up. The link I posted does just that.[/quote]Just curious — there are several requirements when syncing two AM transmitters on the same carrier frequency, when both can be received at the same time on a single receiver. The two r-f carrier frequencies need to be frequency/phase locked (to prevent the heterodyne you mentioned, and by the process that radio8z accurately described), and the program audio on the two transmitters needs to be synchronized in time and modulation polarity (to minimize audio distortion at the receiver). Does the application you linked to do all of those functions?
A further consideration is that the radiation from the two Part 15 AM antennas may increase net coverage range in some directions, and reduce it in others — compared to either system as a standalone operation. That takes some careful engineering to understand and control. Accurately syncing more than two AM transmitters is a real challenge.