§ 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 certificated 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 verified or approved under the provisions
   of part 73 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 certificated 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]

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