§  74.1250   Transmitters and associated equipment.

   (a) FM translator and booster transmitting apparatus, and exciters
   employed to provide a locally generated and modulated input signal to
   translator and booster equipment, used by stations authorized under the
   provisions of this subpart must be certified upon the request of any
   manufacturer of transmitters in accordance with this section and
   subpart J of part 2 of this chapter. In addition, FM translator and
   booster stations may use FM broadcast transmitting apparatus authorized
   via Supplier's Declaration of Conformity or approved under the
   provisions of part 73 of this chapter.

   Note 1 to paragraph (a): The Declaration of Conformity procedure has
   been replaced by Supplier's Declaration of Conformity. Equipment
   previously authorized under subpart J of part 2 of this chapter may
   remain in use. See § 2.950 of this chapter.

   (b) Transmitting antennas, antennas used to receive signals to be
   rebroadcast, and transmission lines are not subject to the requirement
   for certification.

   (c) The following requirements must be met before translator, booster
   or exciter equipment will be certified in accordance with this section:

   (1) Radio frequency harmonics and spurious emissions must conform with
   the specifications of § 74.1236 of this part.

   (2) The local oscillator or oscillators, including those in an exciter
   employed to provide a locally generated and modulated input signal to a
   translator or booster, when subjected to variations in ambient
   temperature between minus 30 degrees and plus 50 degrees centigrade,
   and in primary supply voltage between 85 percent and 115 percent of the
   rated value, shall be sufficiently stable to maintain the output center
   frequency within plus or minus 0.005 percent of the operating frequency
   and to enable conformance with the specifications of § 74.1261 of this
   part.

   (3) The apparatus shall contain automatic circuits to maintain the
   power output in conformance with § 74.1235(e) of this part. If provision
   is included for adjusting the power output, then the normal operating
   constants shall be specified for operation at both the rated power
   output and the minimum power output at which the apparatus is designed
   to operate. The apparatus shall be equipped with suitable meters or
   meter jacks so that the operating constants can be measured while the
   apparatus is in operation.

   (4) Apparatus rated for transmitter power output of more than 1 watt
   shall be equipped with automatic circuits to place it in a nonradiating
   condition when no input signal is being received in conformance with
   § 74.1263(b) of this part and to transmit the call sign in conformance
   with § 74.1283(c)(2) of this part.

   (5) For exciters, automatic means shall be provided for limiting the
   level of the audio frequency voltage applied to the modulator to ensure
   that a frequency swing in excess of 75 kHz will not occur under any
   condition of the modulation.

   [ 55 FR 50698 , Dec. 10, 1990, as amended at  63 FR 36606 , July 7, 1998;
    82 FR 50836 , Nov. 2, 2017]