Sec.  73.669   TV stereophonic aural and multiplex subcarrier operation.

   (a) A TV broadcast station may without specific authority from the FCC,
   transmit multichannel aural programs upon installation of multichannel sound
   equipment. Prior to commencement of multichannel broadcasting, the equipment
   shall be measured in accordance with  Sec. 73.1690(e).

   (b)  Multiplex subcarriers may be used by a TV station pursuant to the
   provisions   of   Sec. 73.665  and  may  be  transmitted  on  a  secondary,
   non-interference basis to broadcast programming without specific authority
   from  the  FCC. Transmissions must be conducted in accordance with the
   technical standards given in  Sec. 73.682(c).

   (c)  In  all  arrangements entered into with outside parties affecting
   non-common carrier subcarrier operation, the licensee or permittee must
   retain control over all material transmitted over the station's facilities,
   with the right to reject any material which is deemed inappropriate or
   undesirable. Subchannel leasing arrangements must be kept in writing at the
   station and made available to the FCC upon request.

   [ 49 FR 18106 , Apr. 27, 1984]