Sec.  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  Sec. 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,  Sec. 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:


------------------------------------------------------------------------
                                                               Minimum
                                                             attenuation
         Distance of emission from center frequency             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]