The examples and perspective in this article deal primarily with the United States and do not represent a worldwide view of the subject. (December 2010)
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.
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 on March 28, 1953.
|Novice / Technician|
|= CW, RTTY and data (US: < 1 kHz bandwidth)|
|= CW, phone and image|
|= CW only (US Novice/Technician: 200 W PEP maximum TPO)|
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.
|= CW only|
|= CW, narrow band digital ( <= 500 Hz )|
|= CW, narrow band digital ( <= 500 Hz ), wide band digital|
|= CW, phone|
|= CW, phone, image ( <= 2700 Hz )|
|= Digital only|
|= Phone only|
|= TV only|
- "We Get 21 Mc." QST, June 1952, p. 29.
- Canadian 0-30 MHz Band Plan http://wp.rac.ca/wp-content/uploads/files/pdf/RAC%20Bandplan%20December%201%202015.pdf accessed 1 December 2015
- "ARRLWeb: US Amateur Bands". Archived from the original on 7 September 2005. Retrieved August 3, 2005.
- "ARRLWeb: ARRL Band Plans". Archived from the original on 3 August 2005. Retrieved August 3, 2005.
- "UK Amateur Radio Bandplans Band Plans". Retrieved August 3, 2005. Click the 15 Meter button at the bottom of the page
- "Ham Radio QRP". Archived from the original on September 24, 2005. Retrieved August 3, 2005.
- "IARU Region 1 Bandplan" (PDF). Retrieved January 1, 2006.
- "IARU Region 2 Bandplan" (PDF). Retrieved January 1, 2008.
- "IARU Region 3 Bandplan". Archived from the original on 2005-05-13. Retrieved August 3, 2005.
|Range||Band||ITU Region 1||ITU Region 2||ITU Region 3|
|LF||2200 m||135.7–137.8 kHz|
|MF||630 m||472–479 kHz|
|160 m||1.810–1.850 MHz||1.800–2.000 MHz|
|HF||80 / 75 m||3.500–3.800 MHz||3.500–4.000 MHz||3.500–3.900 MHz|
|60 m||5.3515–5.3665 MHz|
|40 m||7.000–7.200 MHz||7.000–7.300 MHz||7.000–7.200 MHz|
|30 m[w]||10.100–10.150 MHz|
|20 m||14.000–14.350 MHz|
|17 m[w]||18.068–18.168 MHz|
|15 m||21.000–21.450 MHz|
|12 m[w]||24.890–24.990 MHz|
|10 m||28.000–29.700 MHz|
|VHF||6 m||50.000–52.000 MHz
|4 m[x]||70.000–70.500 MHz||N/A|
|2 m||144.000–146.000 MHz||144.000–148.000 MHz|
|1.25 m||N/A||220.000–225.000 MHz||N/A|
|UHF||70 cm||430.000–440.000 MHz||430.000–440.000 MHz|
|33 cm||N/A||902.000–928.000 MHz||N/A|
|23 cm||1.240–1.300 GHz|
|13 cm||2.300–2.450 GHz|
|SHF||9 cm||3.400–3.475 GHz[y]||3.300–3.500 GHz|
|5 cm||5.650–5.850 GHz||5.650–5.925 GHz||5.650–5.850 GHz|
|3 cm||10.000–10.500 GHz|
|1.2 cm||24.000–24.250 GHz|
|EHF||6 mm||47.000–47.200 GHz|
|4 mm[y]||75.500 GHz[x] – 81.500 GHz||76.000–81.500 GHz|
|2.5 mm||122.250–123.000 GHz|
|2 mm||134.000–141.000 GHz|
|1 mm||241.000–250.000 GHz|
|THF||Sub-mm||Some administrations have authorized spectrum for amateur use in this region;|
others have declined to regulate frequencies above 300 GHz.
[v] All allocations are subject to variation by country. For simplicity, only common allocations found internationally are listed. See a band's article for specifics.
|See also: Radio spectrum, Electromagnetic spectrum|