AM Detuning

Any antenna structure built in close proximity to an AM broadcast station has the possibility of distorting the station’s antenna pattern, which would violate FCC regulations. While wireless signals do not interfere with an AM station’s signals, the antenna structure itself, depending on its height and proximity, can intercept a substantial amount of energy from a nearby station, re-radiate it, and scatter it in other directions. By doing so, the structure produces unapproved changes in the shape of the station’s FCC-licensed coverage area. Wireless licensees must therefore protect the AM station’s pattern and either prove that there is no distortion by the construction or modification of a structure, or minimize its impact by “detuning” the site.