Sec. 73.1560  Operating power and mode tolerances.

    (a) AM stations. (1) Except as provided for in paragraph (d) of this 
section, the antenna input power of an AM station as determined by the 
procedures specified in Sec. 73.51 must be maintained as near as is 
practicable to the authorized antenna input power and may not be less 
than 90% nor more than 105% of the authorized power.
    (2) Whenever the transmitter of an AM station cannot be placed into 
the specified operating mode at the time required, transmissions of the 
station must be immediately terminated. However, if the radiated field 
at any bearing or elevation does not exceed that permitted for that time 
of day, operation in the mode with the lesser radiated field may 
continue under the notification procedures of paragraph (d) of this 
section.
    (b) FM stations. Except as provided in paragraph (d) of this 
section, the transmitter output power of an FM station, with power 
output as determined by the procedures specified in Sec. 73.267, which 
is authorized for output power more than 10 watts must be maintained as 
near as practicable to the authorized transmitter output power and may 
not be less than 90% nor more than 105% of the authorized power. FM 
stations operating with authorized transmitter output power of 10 watts 
or less, may operate at less than the authorized power, but not more 
than 105% of the authorized power.
    (c) TV stations. (1) Except as provided in paragraph (d) of this 
section, the visual output power of a TV transmitter, as determined by 
the procedures specified in Sec. 73.663, must be maintained as near as 
is practicable to the authorized transmitter output power and may not be 
less than 80% nor more than 110% of the authorized power.
    (2) The output power of the aural transmitter shall be maintained to 
provide an aural carrier ERP not to exceed 22% of the peak authorized 
visual ERP.
    (3) The FCC may specify deviation from the power of tolerance 
requirements for subscription television operations to the extent it 
deems necessary to permit proper operation.
    (d) Reduced power operation. In the event it becomes technically 
impossible to operate with the authorized power, a broadcast station may 
operate at reduced power for a period of not more than 30 days without 
specific authority from the FCC. If operation at reduced power will 
exceed 10 consecutive days, a notification must be sent to the FCC in 
Washington, D.C., not

[[Page 276]]

later than the 10th day of the lower power operation. In the event the 
normal power is restored prior to the expiration of the 30 day period, 
the licensee must notify the FCC upon restoration of normal operation. 
If causes beyond the control of the licensee prevent restoration of 
authorized power within 30 days, an informal written request must be 
made to the FCC in Washington, DC, no later than the 30th day for the 
additional time as may be necessary.

[ 44 FR 58734 , Oct. 11, 1979, as amended at  49 FR 22093 , May 25, 1984;  49 FR 29069 , July 18, 1984;  49 FR 47610 , Dec. 6, 1984;  50 FR 26568 , June 
27, 1985;  50 FR 40015 , Oct. 1, 1985]