Sec. 74.961  Frequency tolerance.

    (a) Beginning November 1, 1991, the frequency of the visual carrier 
shall be maintained within &177; 1 KHz of the assigned frequency 
at all times when the station is in operation. Until that date, the 
frequency of the visual carrier shall be maintained within 60 KHz of the 
assigned frequency at all times when the station is in operation. A 
transmitter licensed prior to November 1, 1991, that remains at the 
station site initially licensed and does not comply with this paragraph 
may continue to be used for its life if it does not cause

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harmful interference to the operation 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]