Sec.  15.109   Radiated emission limits.

   (a) Except for Class A digital devices, the field strength of radiated
   emissions from unintentional radiators at a distance of 3 meters shall not
   exceed the following values:


------------------------------------------------------------------------
                                                                Field
                                                              strength
                Frequency of emission (MHz)                 (microvolts/
                                                               meter)
------------------------------------------------------------------------
30-88.....................................................          100
88-216....................................................          150
216-960...................................................          200
Above 960.................................................          500
------------------------------------------------------------------------

   (b) The field strength of radiated emissions from a Class A digital device,
   as determined at a distance of 10 meters, shall not exceed the following:


------------------------------------------------------------------------
                                                                Field
                                                              strength
                Frequency of emission (MHz)                 (microvolts/
                                                               meter)
------------------------------------------------------------------------
30-88.....................................................           90
88-216....................................................          150
216-960...................................................          210
Above 960.................................................          300
------------------------------------------------------------------------

   (c) In the emission tables above, the tighter limit applies at the band
   edges. Sections 15.33 and 15.35 which specify the frequency range over which
   radiated emissions are to be measured and the detector functions and other
   measurement standards apply.

   (d) For CB receivers, the field strength of radiated emissions within the
   frequency range of 25–30 MHz shall not exceed 40 microvolts/meter at a
   distance of 3 meters. The field strength of radiated emissions above 30 MHz
   from such devices shall comply with the limits in paragraph (a) of this
   section.

   (e) Carrier current systems used as unintentional radiators or other
   unintentional radiators that are designed to conduct their radio frequency
   emissions via connecting wires or cables and that operate in the frequency
   range of 9 kHz to 30 MHz, including devices that deliver the radio frequency
   energy to transducers, such as ultrasonic devices not covered under part 18
   of this chapter, shall comply with the radiated emission limits for
   intentional radiators provided in  Sec. 15.209 for the frequency range of 9 kHz
   to 30 MHz. As an alternative, carrier current systems used as unintentional
   radiators and operating in the frequency range of 525 kHz to 1705 kHz may
   comply with the radiated emission limits provided in  Sec. 15.221(a). At
   frequencies above 30 MHz, the limits in paragraph (a), (b), or (g) of this
   section, as appropriate, apply.

   (f) For a receiver which employs terminals for the connection of an external
   receiving antenna, the receiver shall be tested to demonstrate compliance
   with the provisions of this section with an antenna connected to the antenna
   terminals unless the antenna conducted power is measured as specified in
    Sec. 15.111(a). If a permanently attached receiving antenna is used, the
   receiver shall be tested to demonstrate compliance with the provisions of
   this section.

   (g) As an alternative to the radiated emission limits shown in paragraphs
   (a) and (b) of this section, digital devices may be shown to comply with the
   standards contained in Third Edition of the International Special Committee
   on Radio Interference (CISPR), Pub. 22, “Information Technology
   Equipment—Radio Disturbance Characteristics—Limits and Methods of
   Measurement” (incorporated by reference, see  Sec. 15.38). In addition:

   (1) The test procedure and other requirements specified in this part shall
   continue to apply to digital devices.

   (2) If, in accordance with  Sec. 15.33 of this part, measurements must be
   performed above 1000 MHz, compliance above 1000 MHz shall be demonstrated
   with the emission limit in paragraph (a) or (b) of this section, as
   appropriate. Measurements above 1000 MHz may be performed at the distance
   specified in the CISPR 22 publications for measurements below 1000 MHz
   provided the limits in paragraphs (a) and (b) of this section are
   extrapolated to the new measurement distance using an inverse linear
   distance extrapolation factor (20 dB/decade), e.g., the radiated limit above
   1000 MHz for a Class B digital device is 150 uV/m, as measured at a distance
   of 10 meters.

   (3) The measurement distances shown in CISPR Pub. 22, including measurements
   made in accordance with this paragraph above 1000 MHz, are considered, for
   the purpose of  Sec. 15.31(f)(4) of this part, to be the measurement distances
   specified in this part.

   (4) If the radiated emissions are measured to demonstrate compliance with
   the alternative standards in this paragraph, compliance must also be
   demonstrated with the conducted limits shown in  Sec. 15.107(e).

   (h) Radar detectors shall comply with the emission limits in paragraph (a)
   of this section over the frequency range of 11.7–12.2 GHz.

   [ 54 FR 17714 , Apr. 25, 1989, as amended at  56 FR 373 , Jan. 4, 1991;  58 FR 51249 , Oct. 1, 1993;  66 FR 19098 , Apr. 13, 2001;  67 FR 48993 , July 29, 2002;
    69 FR 2849 , Jan. 21, 2004]