Currently RHZ runs on several AM transmitters whose boundaries have not fully met yet. The broadcast ranges have varied from about 1/8mile to 1 mile in radius. Because the areas have not started to intersect, there has been little concern to our listeners about sharing space.
When broadcast ranges do meet up, reception will be fuzzier where the the boundries cross. The audio signal is syncronized within a few milli-seconds, the content will match up but not the exact broadcast waves. Getting transmission signals "in phase" exactly is tricky, the transmitter must be an advanced model with this feature. In a car you would just drive through this area, and if your house rests in this area, you will have to adjust your antenna to try to focus on one transmitter over another.
We are developing ways to syncronize the transmission signals in phase, meaning where the actual broadcast waves line up exactly and will not cause interferance. We are experimenting with using both GPS and atomic clock systems as ways to syncronize the signals completly.