Editing Broadcast range (section)

==Legal definitions==
The "primary service area" is the area served by a station's strongest signal.  The "city-grade contour" is 70 dBμ ([[decibel]]s relative to one microvolt per meter of signal strength) or 3.16mV/m (millivolts per meter) for FM stations in the [[United States]], according to [[Federal Communications Commission]] (FCC) regulations.  This is also significant in [[broadcast law]], in that a station must cover its [[city of license]] within this area, except for [[non-commercial educational]] and [[low-power broadcasting|low-power]] stations.

The legally protected range of a station extends beyond this range, out to the point where signal strength is expected to be 1mV/m for most stations in [[North America]], though for [[List of North American broadcast station classes#AM|class B1]] stations it is 0.7mV/m, and as low as 0.5mV/m for full class B stations (the maximum allowed in densely [[population|populate]]d areas of both [[Canada]] and the U.S.).