Sec. 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 Secs. 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]