§  73.1670   Auxiliary transmitters.

   (a) A licensee of a broadcast station may, without further authority
   from the FCC, install and use with the main antenna system one or more
   auxiliary transmitters for the following purposes:

   (1) The transmission of regular programs upon failure of the main
   transmitter.

   (2) The transmission of regular programs during maintenance or
   modification of the main transmitter.

   (3) Emergency broadcast system operation.

   (4) The transmission of regular programs by an AM station authorized
   for Presunrise (PSRA) and/or Postsunset (PSSA) operation.

   (5) The transmission of tests to determine the operating condition of
   the auxiliary transmitter or auxiliary antenna.

   (6) For testing, upon the request of representatives of the FCC.

   (b) Authorization to install an auxiliary transmitter for use with
   other than the main antenna or authorized auxiliary antenna must be
   obtained by filing an application for a construction permit on FCC form
   301 (FCC form 340 for noncommercial educational stations).

   (c) The following technical and operating standards apply to auxiliary
   transmitters:

   (1) The auxiliary transmitter may be operated on only the station's
   authorized frequency and within the required carrier frequency
   departure tolerance for the type of station.

   (2) The carrier frequency of the auxiliary transmitter must be measured
   as often as necessary to ensure that it is maintained within the
   prescribed tolerance.

   (3) When using an auxiliary transmitter, the operating power may be
   less than the authorized power but may not exceed the authorized power
   within the permitted tolerance for the type of station. If operation
   with an auxiliary transmitter at reduced power continues for a period
   exceeding 10 days, the FCC in Washington, DC must be notified. (See
   § 73.51, AM; § 73.267, FM; § 73.567, NCE-FM; and § 73.663, TV).

   (4) Normal operator requirements apply to the operation of the
   auxiliary transmitter.

   Note: After January 1, 1979, new licenses will not be issued nor will
   existing licenses be renewed for auxiliary transmitters that are
   operated into the main antenna system.

   [ 43 FR 53741 , Nov. 17, 1978, as amended at  44 FR 22740 , Apr. 17, 1979;
    48 FR 36463 , Aug. 11, 1983;  48 FR 42960 , Sept. 20, 1983;  48 FR 44806 ,
   Sept. 30, 1983;  50 FR 32417 , Aug. 12, 1985;  51 FR 32088 , Sept. 9, 1986]