§  73.1540   Carrier frequency measurements.

   (a) The carrier frequency of each AM and FM station and the visual
   carrier frequency and the difference between the visual carrier and the
   aural carrier or center frequency of each TV and Class A TV station
   shall be measured or determined as often as necessary to ensure that
   they are maintained within the prescribed tolerances.

   (b) In measuring the carrier frequency, the licensee may use any method
   or procedure that has sufficient precision to establish that the
   carrier frequency is within the prescribed departure limits.

   (c) The primary standard of frequency for radio frequency measurements
   is the standard frequency maintained by the National Bureau of
   Standards or the standard signals of Stations WWV, WWVB, and WWVH of
   the National Bureau of Standards.

   [ 43 FR 32783 , July 28, 1978, as amended at  48 FR 44805 , Sept. 30, 1983;
    65 FR 30004 , May 10, 2000]