|The Federal Communications Commission (FCC) is the authority
in the United States of America that creates and enforces the use of airwaves throughout the entire
radio frequency spectrum. This group of documents contains the entirety of the
FCC Part 15 regulations
that concern unlicensed radio frequency devices. As with all government documents, this material
is in the public domain and may be freely copied so long as the content is not changed. This copy
is provided as a convenience for RF Cafe visitors.
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Table of Contents.
[Code of Federal Regulations]
[Title 47, Volume 1]
[Revised as of October 1, 2008]
From the U.S. Government Printing Office via GPO Access
CHAPTER I--FEDERAL COMMUNICATIONS COMMISSION
PART 15_RADIO FREQUENCY DEVICES--Table of Contents
Subpart C_Intentional Radiators
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.
(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
(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
(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]