27.63—Disturbance of AM broadcast station antenna patterns.
AWS and WCS licensees that construct or modify towers in the immediate vicinity of AM broadcast stations are responsible for measures necessary to correct disturbance of the AM station antenna pattern which causes operation outside of the radiation parameters specified by the FCC for the AM station, if the disturbance occurred as a result of such construction or modification.
(a) Non-directional AM stations.
If tower construction or modification is planned within 1 kilometer (0.6 mile) of a non-directional AM broadcast station tower, the AWS or WCS licensee must notify the licensee of the AM broadcast station in advance of the planned construction or modification. Measurements must be made to determine whether the construction or modification would affect the AM station antenna pattern. The AWS or WCS licensee is responsible for the installation and continued maintenance of any detuning apparatus necessary to restore proper non-directional performance of the AM station tower.
(b) Directional AM stations.
If tower construction or modification is planned within 3 kilometers (1.9 miles) of a directional AM broadcast station array, the AWS or WCS licensee must notify the licensee of the AM broadcast station in advance of the planned construction or modification. Measurements must be made to determine whether the construction or modification would affect the AM station antenna pattern. The AWS or WCS licensee is responsible for the installation and continued maintenance of any detuning apparatus necessary to restore proper performance of the AM station array.
[69 FR 5715, Feb. 6, 2004]