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(Redirected from 15 meter)
Amateur radio frequency band
This article is about the amateur radio band. For the international shortwave radio band, see shortwave bands.
The 15-meter band (also called the 21-MHz band or 15 meters) is an amateur radio frequency band spanning the shortwave spectrum from 21 to 21.45 MHz. The band is suitable for amateur long-distance communications, and such use is permitted in nearly all countries.
Because 15-meter waves propagate primarily via reflection off of the F-2 layer of the ionosphere, the band is most useful for intercontinental communication during daylight hours, especially in years close to solar maxima, but the band permits long-distance without high-power station equipment outside such ideal windows. The 15-meter wavelength is harmonically related to that of the 40-meter band, so it is often possible to use an antenna designed for 40 meters.
History
The 15-meter band was designated by the 1947 International Radio Conference of Atlantic City in part to compensate for the loss of the 160-meter band to amateurs by the introduction of LORAN during World War II. The 15-meter band opened to amateurs for CW operation only in the United States on May 1, 1952, and telephony operations were authorized above 21.25 MHz and Novice CW operations between 21.100 and 21.250 MHz on March 28, 1953.
= CW only (US Novice/Technician: 200 W PEP maximum TPO)
Canada
Canada is part of region 2 and as such is subject to the IARU band plan. Radio Amateurs of Canada offers the bandplan below as a recommendation for use by radio amateurs in that country but it does not have the force of law and should only be considered a suggestion or guideline.
Some administrations have authorized spectrum for amateur use in this region; others have declined to regulate frequencies above 300 GHz.
All allocations are subject to variation by country. For simplicity, only common allocations found internationally are listed. See a band's article for specifics.
HF allocation created at the 1979 World Administrative Radio Conference. These are commonly called the "WARC bands".
This is not mentioned in the ITU's Table of Frequency Allocations, but many individual administrations have commonly adopted this allocation under "Article 4.4".
This includes a currently active footnote allocation mentioned in the ITU's Table of Frequency Allocations. These allocations may only apply to a group of countries.