§  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 § 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 § 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 § 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 § 15.209.

   (3) The conducted limits specified in § 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]