§  1.30003   Installations on an AM antenna.

   (a) Installations on a nondirectional AM tower. When antennas are
   installed on a nondirectional AM tower the AM station shall determine
   the operating power by the indirect method (see § 73.51 of this
   chapter). Upon completion of the installation, antenna impedance
   measurements on the AM antenna shall be made. If the resistance of the
   AM antenna changes by more than 2 percent (see § 73.45(c)(1) of this
   chapter), an application on FCC Form 302-AM (including a tower sketch
   of the installation) shall be filed with the Commission for the AM
   station to return to direct power measurement.

   (b) Installations on a directional AM array. Before antennas are
   installed on a tower in a directional AM array, the proponent shall
   notify the AM station so that, if necessary, the AM station may
   determine operating power by the indirect method (see § 73.51 of this
   chapter) and request special temporary authority pursuant to § 73.1635
   of this chapter to operate with parameters at variance.

   (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.

   (c) Form 302-AM Filing. When the AM station is required to file Form
   302-AM following an installation as set forth in paragraphs (a) and (b)
   of this section, the Form 302-AM shall be filed before or
   simultaneously with any license application associated with the
   installation. If no license application is filed as a result of the
   installation, the Form 302-AM shall be filed within 30 days after the
   completion of the installation.

   [ 78 FR 66295 , Nov. 5, 2013]