FAQ: Two LPFM stations are spaced precisely 24 km apart, is interference between the stations still possible?
In some cases, yes. The 24 km spacing is based on the 5.6 km standard service contour for a full LPFM facility (100 watts at 30 meters height above average terrain) and the 18.6 km interference contour for a full LPFM facility (5.6 + 18.6 = 24.2 rounded down to 24). Due to terrain in some directions, it is very possible that your LPFM service contour will extend well past 5.6 km. This will also result in the growth of your interference contour this resulting in it potentially overlapping the other LPFM station's service contour. This may or may not result in interference to the other LPFM station's fringe areas in the direction of your station.