Sec. 73.61  AM directional antenna field strength measurements.

    (a) Each AM station using a directional antenna must make field 
strength measurements at the monitoring point locations specified in the 
instrument of authorization, as often as necessary to ensure that the 
field at those points does not exceed the values specified in the 
station authorization. Additionally, stations not having an approved 
sampling system must make the measurements once each calendar quarter at 
intervals not exceeding 120 days. The provision of this paragraph 
supersedes any schedule specified on a station license issued prior to 
January 1, 1986. The results of the measurements are to be entered into 
the station log pursuant to the provisions of Sec. 73.1820.
    (b) Partial proof of performance measurements using the procedures 
described in Sec. 73.154 must be made whenever the licensee has reason 
to believe that the radiated field may be exceeding the limits for which 
the station was most recently authorized to operate.
    (c) A station may be directed to make a partial proof of performance 
by the FCC whenever there is an indication that the antenna is not 
operating as authorized.

[ 50 FR 47054 , Nov. 14, 1985]