LPFM Foothill Effect Calculator

"Foothill Effect" is where a LPFM or full-service FM station is at a location where there very high elevation in one direction and very low elevation in the other. This results in a low height above average terrain thus allowing for at or near maximum power for the service class (100 watts for LPFM). As a result, stations would have a 60 dBu service contour going over a much longer distance in the directions of the lower elevation. This was addressed as a concern in RM-11909 (Simple250) that such stations could create interference to other stations as LPFM stations are spaced by distance instead of contours. In response, REC suggested that a very small number of LPFM stations that would otherwise meet distance separation rules would not be able to upgrade if they have a 60 dBu contour that extends at least 21 kilometers or more (rounded) in any direction of more than 20 consecutive degrees. This search tool will use the FCC Contours API to determine the service contour size in 360 different directions to determine if the station would not be able to upgrade under this proposed compromise. This tool does not show LP250 availability. To check potential LP250 upgrade availability, use check.lp250.com
Enter LPFM station call sign (without the -LP): -LP