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:
   Frequency (MHz) Field strength (microvolts/meter) Measurement distance
   (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]