Sec. 15.215  Additional provisions to the general radiated emission 
          limitations.

    (a) The regulations in Secs. 15.217 through 15.255 provide 
alternatives to the general radiated emission limits for intentional 
radiators operating in specified frequency bands. Unless otherwise 
stated, there are no restrictions as to the types of operation permitted 
under these sections.
    (b) In most cases, unwanted emissions outside of the frequency bands 
shown in these alternative provisions must be attenuated to the emission 
limits shown in Sec. 15.209. In no case shall the level of the unwanted 
emissions from an intentional radiator operating under these additional 
provisions exceed the field strength of the fundamental emission.
    (c) For those bands of frequencies where alternative radiated 
emission limitations apply and for which a frequency stability is not 
specified, it is recommended that the fundamental frequency be kept 
within at least the central 80% of the permitted band in order to 
minimize the possibility of out-of-band operation.
    (d) Where the following sections specify limits on the bandwidth of 
the emissions, the bandwidth limits include the effects of frequency 
sweeping, frequency hopping, and other modulation techniques which may 
be employed.
[ 54 FR 17714 , Apr. 25, 1989, as amended at  62 FR 45333 , Aug. 27, 1997]