Code of Federal Regulations Title 47. Telecommunication § 47.1.30003 Installations on an AM antenna

(1) For AM stations licensed via field strength measurements (see § 73.151(a)), a partial proof of performance as defined by § 73.154 of this chapter shall be conducted by the tower proponent both before and after construction to establish that the AM array will not be and has not been adversely affected. If the operating parameters of the AM array change following the installation, the results of the partial proof of performance shall be filed by the AM station with the Commission on Form 302–AM.

(2) For AM stations licensed via a moment method proof (see § 73.151(c) of this chapter), a base impedance measurement on the tower being modified shall be made by the tower proponent as described in § 73.151(c)(1). The result of the new tower impedance measurement shall be retained in the station's records. If the new measured base resistance and reactance values of the affected tower differ by more than ±2 ohms and ±4 percent from the corresponding modeled resistance and reactance values contained in the last moment method proof, then the station shall file Form 302–AM. The Form 302–AM shall be accompanied by the new impedance measurements for the modified tower and a new moment method model for each pattern in which the tower is a radiating element. Base impedance measurements for other towers in the array, sampling system measurements, and reference field strength measurements need not be repeated. The procedures described in this paragraph may be used as long as the affected tower continues to meet the requirements for moment method proofing after the modification.