§  74.1236   Emission and bandwidth.

   (a) The license of a station authorized under this subpart allows the
   transmission of either F3 or other types of frequency modulation (see
   § 2.201 of this chapter) upon a showing of need, as long as the
   emission complies with the following:

   (1) For transmitter output powers no greater than 10 watts, paragraphs
   (b), (c), and (d) of this section apply.

   (2) For transmitter output powers greater than 10 watts, § 73.317 (a),
   (b), (c), and (d) apply.

   (b) Standard width FM channels will be assigned and the transmitting
   apparatus shall be operated so as to limit spurious emissions to the
   lowest practicable value. Any emissions including intermodulation
   products and radiofrequency harmonics which are not essential for the
   transmission of the desired aural information shall be considered to be
   spurious emissions.

   (c) The power of emissions appearing outside the assigned channel shall
   be attenuated below the total power of the emission as follows:
   Distance of emission from center frequency Minimum attenuation below
   unmodulated carrier
   120 to 240 kHz 25 dB
   Over 240 and up to 600 kHz 35 dB
   Over 600 kHz 60 dB

   (d) Greater attenuation than that specified in paragraph (c) of this
   section may be required if interference results outside the assigned
   channel.

   [ 35 FR 15388 , Oct. 2, 1970, as amended at  52 FR 31406 , Aug. 20, 1987;
    55 FR 50698 , Dec. 10, 1990]