Sec.  15.221   Operation in the band 525–1705 kHz.

   (a) Carrier current systems and transmitters employing a leaky coaxial cable
   as the radiating antenna may operate in the band 525–1705 kHz provided the
   field strength levels of the radiated emissions do not exceed 15 uV/m, as
   measured at a distance of 47,715/(frequency in kHz) meters (equivalent to
   Lambda/2Pi) from the electric power line or the coaxial cable, respectively.
   The field strength levels of emissions outside this band shall not exceed
   the general radiated emission limits in  Sec. 15.209.

   (b) As an alternative to the provisions in paragraph (a) of this section,
   intentional radiators used for the operation of an AM broadcast station on a
   college  or  university campus or on the campus of any other education
   institution may comply with the following:

   (1) On the campus, the field strength of emissions appearing outside of this
   frequency band shall not exceed the general radiated emission limits shown
   in  Sec. 15.209 as measured from the radiating source. There is no limit on the
   field strength of emissions appearing within this frequency band, except
   that the provisions of  Sec. 15.5 continue to comply.

   (2) At the perimeter of the campus, the field strength of any emissions,
   including those within the frequency band 525–1705 kHz, shall not exceed the
   general radiated emission in  Sec. 15.209.

   (3) The conducted limits specified in  Sec. 15.207 apply to the radio frequency
   voltage on the public utility power lines outside of the campus. Due to the
   large number of radio frequency devices which may be used on the campus,
   contributing to the conducted emissions, as an alternative to measuring
   conducted emissions outside of the campus, it is acceptable to demonstrate
   compliance with this provision by measuring each individual intentional
   radiator employed in the system at the point where it connects to the AC
   power lines.

   (c) A grant of equipment authorization is not required for intentional
   radiators operated under the provisions of this section. In lieu thereof,
   the  intentional  radiator  shall  be verified for compliance with the
   regulations in accordance with subpart J of part 2 of this chapter. This
   data shall be kept on file at the location of the studio, office or control
   room associated with the transmitting equipment. In some cases, this may
   correspond to the location of the transmitting equipment.

   (d) For the band 535–1705 kHz, the frequency of operation shall be chosen
   such that operation is not within the protected field strength contours of
   licensed AM stations.

   [ 56 FR 373 , Jan. 4, 1991]