§  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., § §  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 § §  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 §  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 §  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 §  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 §  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]

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