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]