Sec. 90.263  Substitution of frequencies below 25 MHz.

    Frequencies below 25 MHz when shown in the radio pool frequency 
listings under this part will be assigned to base or mobile stations 
only upon a satisfactory showing that, from a safety of life standpoint, 
frequencies above 25 MHz will not meet the operational requirements of 
the applicant. These frequencies are available for assignment in many 
areas; however, in individual cases such assignment may be impracticable 
due to conflicting frequency use authorized to stations in other 
services by this and other countries. In such cases, a substitute 
frequency, if found to be available, may be assigned from the following 
bands 1605-1750, 2107-2170, 2194-2495, 2506-2850, 3155-3400, or 4438-
4650 kHz. Since such assignments are in certain instances subject to 
additional technical and operation limitation, it is necessary that each 
application also include precise information concerning transmitter 
output power, type and directional characteristics, if any, of the 
antenna, and the minimum necessary hours of operation. (This section is 
not applicable to the Radiolocation Radio Service, subpart F.)
[ 43 FR 54791 , Nov. 22, 1978, as amended at  62 FR 18929 , Apr. 17, 1997]

    Effective Date Note: At  62 FR 18929 , Apr. 17, 1997, Sec. 90.263 was 
amended by revising the first sentence, effective Oct. 17, 1997.