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FCC Part 15 Radio Frequency Devices
Section 15.221

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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[Code of Federal Regulations]
[Title 47, Volume 1]
[Revised as of October 1, 2008]
From the U.S. Government Printing Office via GPO Access
[CITE: 47CFR15.221]
[Page 809-810]
                       TITLE 47--TELECOMMUNICATION
                     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/
[[Page 810]]
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 
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 
    (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]

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