Sec.  2.1057   Frequency spectrum to be investigated.

   (a)  In  all of the measurements set forth in  Sec.  Sec. 2.1051 and 2.1053, the
   spectrum  shall be investigated from the lowest radio frequency signal
   generated in the equipment, without going below 9 kHz, up to at least the
   frequency shown below:

   (1) If the equipment operates below 10 GHz: to the tenth harmonic of the
   highest fundamental frequency or to 40 GHz, whichever is lower.

   (2) If the equipment operates at or above 10 GHz and below 30 GHz: to the
   fifth harmonic of the highest fundamental frequency or to 100 GHz, whichever
   is lower.

   (3) If the equipment operates at or above 30 GHz: to the fifth harmonic of
   the highest fundamental frequency or to 200 GHz, whichever is lower.

   (b) Particular attention should be paid to harmonics and subharmonics of the
   carrier frequency as well as to those frequencies removed from the carrier
   by multiples of the oscillator frequency. Radiation at the frequencies of
   multiplier stages should also be checked.

   (c) The amplitude of spurious emissions which are attenuated more than 20 dB
   below the permissible value need not be reported.

   (d) Unless otherwise specified, measurements above 40 GHz shall be performed
   using a minimum resolution bandwidth of 1 MHz.

   [ 61 FR 14502 , Apr. 2, 1996. Redesignated and amended at  63 FR 36599 , July 7,
   1998]