47 CFR 15.221
§ 15.221 Operation in the band 525-1705 kHz.
United States · 47 CFR — Telecommunication · Status: effective
Cite this
- Citation
- 47 CFR 15.221, § 15.221 Operation in the band 525-1705 kHz, United States, version 1 as recorded 2026-07-09, yourstate.us, https://yourstate.us/provision/234433
- Permanent ID
ys:prov:234433@1- SHA-256
02a832b19b78db80a4ebfc2b846ba97e5b148d6ce00cc179e3004e1db3789b3b
The hash is SHA-256 of this version's text, with every run of whitespace collapsed to a single space and the ends trimmed. The ID always leads back here, and checking it says whether the text you cited is still the current version.
Full text
(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.
Legislative history
This is a federal regulation, adopted through agency rulemaking under the Administrative Procedure Act — not enacted by a recorded vote of Congress.