Sec.  21.118   Transmitter construction and installation.

   

   (a) The equipment at the operating and transmitting positions shall be
   so installed and protected that it is not accessible to, or capable of
   being operated by, persons other than those duly authorized by the
   licensee.

   (b) In any case where the maximum modulating frequency of a
   transmitter is prescribed by the Commission, the transmitter shall be
   equipped with a low-pass or band-pass modulation filter of suitable
   performance characteristics. In those cases where a modulation limiter
   is employed, the modulation filter shall be installed between the
   transmitter stage in which limiting is effected and the modulated
   stage of the transmitter.

   (c) Each transmitter employed in these services shall be equipped with
   an appropriately labeled pilot lamp or meter which will provide
   continuous visual indication at the transmitter when its control
   circuits have been placed in a condition to activate the transmitter.
   Such requirement will not be applicable to MDS response stations or
   MDS booster stations authorized pursuant to Sec. 21.913(e). In addition,
   facilities shall be provided at each transmitter to permit the
   transmitter to be turned on and off independently of any remote
   control circuits associated therewith.

   (d) [Reserved]

   (e) At each transmitter control point the following facilities shall
   be installed:

   (1) A carrier operated device which will provide continuous visual
   indication when the transmitter is radiating, or, in lieu thereof, a
   pilot lamp or meter which will provide continuous visual indication
   when the transmitter control circuits have been placed in a condition
   to activate the transmitter.

   (2) Facilities which will permit the operator to turn transmitter
   carrier on and off at will.

   (f) Transmitter control circuits from any control point shall be so
   installed that grounding or shorting any line in the control circuit
   will not cause the transmitter to radiate: Provided, however, That
   this provision shall not be applicable to control circuits of stations
   which normally operate with continuous radiation or to control
   circuits which are under the effective operational control of
   responsible operating personnel 24 hours per day.

   [ 44 FR 60534 , Oct. 19, 1979, as amended at  52 FR 37783 , Oct. 9, 1987;
    63 FR 65101 , Nov. 25, 1998]