---
kind: "section"
citation: "47 C.F.R. § 90.266"
title: "47"
number: "90.266"
heading: "Long distance communications on frequencies below 25 MHz."
url: "https://uscodex.org/cfr/47/90.266"
---

# §90.266. Long distance communications on frequencies below 25 MHz.

- (a) The use of any particular frequency between 2 and 25 MHz is limited to those frequencies falling within the bands allocated to the fixed and land mobile services as indicated in [§ 2.106](/cfr/47/2.106.md) of the Commission's Rules and Regulations.
- (b) Only in the following circumstances will authority be extended to stations to operate on the frequencies below 25 MHz:
  - (1) To provide communications circuits to support operations which are highly important to the national interest and where other means of telecommunication are unavailable;
  - (2) To provide standby and/or backup communications circuits to regular domestic communications circuits which have been disrupted by disasters and/or emergencies.
- (c) No protection is afforded to users of these frequencies from harmful interference caused by foreign operations.
- (d) In the event that a complaint of harmful interference resulting from operation of these circuits is received from a foreign source, the offending circuit(s) must cease operation on the particular frequency concerned immediately upon notification by the Commission.
- (e) In order to accommodate the situations described in paragraphs [(c)](#c) and [(d)](#d) of this section, the equipment shall be capable of transmitting and receiving on any frequency within the bands between 2 and 25 MHz and capable of immediate change among the frequencies, provided, however, that this requirement does not apply to equipment manufactured prior to August 15, 1983.
- (f) Only 2K80J3E, 100HA1A, 100HA1B and those emission types listed in [§ 90.237(g)](/cfr/47/90.237.md?p=g) are permitted.
- (g) Applicants must fulfill eligibility requirements set out in [§ 90.35(c)(1)](/cfr/47/90.35.md?p=c-1) and submit communications plans pursuant to [§ 90.129(o)](/cfr/47/90.129.md?p=o).
- (h) Exercises or circuits tests which require use of these frequencies for more than seven hours per week cumulative are prohibited unless prior written approval is obtained from the Commission.

## Notes

### Amendments

[48 FR 32996, July 20, 1983, as amended at 49 FR 48712, Dec. 14, 1984; 52 FR 29856, Aug. 12, 1987; 62 FR 18929, Apr. 17, 1997]

### Authority

Authority: 47 U.S.C. 154(i), 161, 303(g), 303(r), 332(c)(7), 1401-1473

### Source

Source: 43 FR 54791, Nov. 22, 1978, unless otherwise noted.

### Amendments

[48 FR 32996, July 20, 1983, as amended at 49 FR 48712, Dec. 14, 1984; 52 FR 29856, Aug. 12, 1987; 62 FR 18929, Apr. 17, 1997]