Sec.  74.961   Frequency tolerance.

   

   (a) Beginning January 21, 2000, equipment authorized to be used at all
   ITFS main stations, and at all ITFS booster stations authorized
   pursuant to Sec. 74.985(b), shall maintain a frequency tolerance of
   0.001%. ITFS booster stations authorized pursuant to Sec. 74.985(e) and
   ITFS response stations authorized pursuant to Sec. 74.939 shall employ
   transmitters with sufficient frequency stability to ensure that the
   emission is, at all times, within the required emission mask. A
   transmitter licensed prior to November 1, 1991 that remains at the
   station site for which it was initially authorized and does not comply
   with the provisions of this paragraph may continue to be used if it
   does not cause harmful interference to the operations of any other
   licensee. Any non-conforming transmitter replaced after November 1,
   1991 must be replaced by a transmitter meeting the requirements of
   this paragraph.

   (b) For television transmission, the peak power of the accompanying
   aural signal must not exceed 10 percent of the peak visual power of
   the transmitter.

   (c) Any licensee with transmission equipment conforming to the
   transmitter tolerance standard of this section can be required to use
   frequency offset where it is demonstrated to be necessary to avoid
   harmful interference with another station.

   [ 55 FR 46014 , Oct. 31, 1990, as amended at  63 FR 65124 , Nov. 25, 1998;
    64 FR 63743 , Nov. 22, 1999]