Sec.  15.209   Radiated emission limits; general requirements.

   

   (a) Except as provided elsewhere in this subpart, the emissions from
   an intentional radiator shall not exceed the field strength levels
   specified in the following table:


------------------------------------------------------------------------
                                                             Measurement
         Frequency (MHz)                Field strength         distance
                                      (microvolts/meter)       (meters)
------------------------------------------------------------------------
0.009-0.490......................  2400/F(kHz)                      300
0.490-1.705......................  24000/F(kHz)                      30
1.705-30.0.......................  30                                30
30-88............................  100 **                             3
88-216...........................  150 **                             3
216-960..........................  200 **                             3
Above 960........................  500                                3
------------------------------------------------------------------------
** Except as provided in paragraph (g), fundamental emissions from
  intentional radiators operating under this section shall not be
  located in the frequency bands 54-72 MHz, 76-88 MHz, 174-216 MHz or
  470-806 MHz. However, operation within these frequency bands is
  permItted under other sections of this part, e.g., Sec. Sec.  15.231
  and 15.241.

   (b) In the emission table above, the tighter limit applies at the band
   edges.

   (c) The level of any unwanted emissions from an intentional radiator
   operating under these general provisions shall not exceed the level of
   the fundamental emission. For intentional radiators which operate
   under the provisions of other sections within this part and which are
   required to reduce their unwanted emissions to the limits specified in
   this table, the limits in this table are based on the frequency of the
   unwanted emission and not the fundamental frequency. However, the
   level of any unwanted emissions shall not exceed the level of the
   fundamental frequency.

   (d) The emission limits shown in the above table are based on
   measurements employing a CISPR quasi-peak detector except for the
   frequency bands 9-90 kHz, 110-490 kHz and above 1000 MHz. Radiated
   emission limits in these three bands are based on measurements
   employing an average detector.

   (e) The provisions in Sec. Sec. 15.31, 15.33, and 15.35 for measuring
   emissions at distances other than the distances specified in the above
   table, determining the frequency range over which radiated emissions
   are to be measured, and limiting peak emissions apply to all devices
   operated under this part.

   (f) In accordance with Sec. 15.33(a), in some cases the emissions from an
   intentional radiator must be measured to beyond the tenth harmonic of
   the highest fundamental frequency designed to be emitted by the
   intentional radiator because of the incorporation of a digital device.
   If measurements above the tenth harmonic are so required, the radiated
   emissions above the tenth harmonic shall comply with the general
   radiated emission limits applicable to the incorporated digital
   device, as shown in Sec. 15.109 and as based on the frequency of the
   emission being measured, or, except for emissions contained in the
   restricted frequency bands shown in Sec. 15.205, the limit on spurious
   emissions specified for the intentional radiator, whichever is the
   higher limit. Emissions which must be measured above the tenth
   harmonic of the highest fundamental frequency designed to be emitted
   by the intentional radiator and which fall within the restricted bands
   shall comply with the general radiated emission limits in Sec. 15.109 that
   are applicable to the incorporated digital device.

   (g) Perimeter protection systems may operate in the 54-72 MHz and
   76-88 MHz bands under the provisions of this section. The use of such
   perimeter protection systems is limited to industrial, business and
   commercial applications.

   [ 54 FR 17714 , Apr. 25, 1989;  54 FR 32339 , Aug. 7, 1989;  55 FR 18340 ,
   May 2, 1990;  62 FR 58658 , Oct. 30, 1997]