§  73.297   FM stereophonic sound broadcasting.

   (a) An FM broadcast station may, without specific authority from the
   FCC, transmit stereophonic (biphonic, quadraphonic, etc.) sound
   programs upon installation of stereophonic sound transmitting equipment
   under the provisions of § § 2.1001, 73.322, and 73.1590 of the Rules.
   Prior to commencement of stereophonic sound broadcasting, equipment
   performance measurements must be made to ensure that the transmitted
   signal complies with all applicable rules and standards.

   (b) Each licensee or permittee engaging in multichannel broadcasting
   must measure the pilot subcarrier frequency as often as necessary to
   ensure that it is kept at all times within 2 Hz of the authorized
   frequency.

   [ 48 FR 28454 , June 22, 1983, and  48 FR 38479 , Aug. 24, 1983]