Sec.  90.427   Precautions against unauthorized operation.

   (a) Each transmitter shall be so installed and protected that it is not
   accessible to or capable of operation by persons other than those duly
   authorized by and under the control of the licensee. Provisions of this part
   authorizing certain unlicensed persons to operate stations, or authorizing
   unattended operation of stations in certain circumstances, shall not be
   construed to change or diminish in any respect the responsibility of station
   licensees to maintain control over the stations licensed to them (including
   all transmitter units thereof), or for the proper functioning and operation
   of those stations and transmitter units in accordance with the terms of the
   licenses of those stations.

   (b) Except for frequencies used in accordance with  Sec. 90.417, no person shall
   program into a transmitter frequencies for which the licensee using the
   transmitter is not authorized.

   [ 43 FR 54791 , Nov. 22, 1978, as amended at  52 FR 47570 , Dec. 15, 1987]