FCC signal contours cannot adequately portray a FM or TV station’s actual useable signal area. Their inadequacy becomes evident when terrain is hilly or mountainous; as the FCC only considers terrain variations within 12 miles of the transmitter site. In such situations a station can have major signal problems in areas that lie within its FCC 1 mv/m (60 dbu) contour. Conversely, some stations can have excellent signal coverage in areas well beyond their FCC contours.

Advanced computer modeling systems now make it possible to calculate a station’s actual signal coverage with an accuracy that was not possible only a few years ago. The following maps show situations where radio stations have signal coverage which is significantly less, or greater than their FCC 60 dbu contours.

 

The FCC 60 dbu (1 mv/m) Contour suggests that the station’s signal covers a major portion of a market’s central city. However, due to terrain shadowing, major areas within the FCC contour have signal problems.

The significance of the signal coverage becomes more important when compared with the resident population of the Metro area.

In contrast, another station with a transmitter that is further away has a better signal.

Exploitation of signal studies like these can represent untapped potential for astute broadcasters throughout the world.