15-meter band

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 on March 28, 1953.[1]

Frequency allocation

United States

Megahertz	21.000–21.025	21.025–21.200	21.200–21.225	21.225–21.275	21.275–21.450
Novice / Technician
General
Advanced
Extra

Key

	= CW, RTTY and data (US: < 1 kHz bandwidth)
	= CW, phone and image
	= 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.[2]

License class	21.000-21.070	21.070-21.080	21.080-21.083	21.083-21.090	21.090-21.125	21.125-21.150	21.150-21.340	21.340-21.343	21.343-21.450
Basic(+), Advanced

Key

	= CW only
	= CW, narrow band digital ( <= 500 Hz )
	= CW, narrow band digital ( <= 500 Hz ), wide band digital
	= Beacons
	= CW, phone
	= CW, phone, image ( <= 2700 Hz )
	= Digital only
	= Phone only
	= TV only

See also

• Shortwave bands

References

1. "We Get 21 Mc." QST, June 1952, p. 29.
2. 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.

International amateur radio frequency allocations
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 (50.000–54.000 MHz)^[y]	50.000–54.000 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 (420.000–450.000 MHz)^[y]
	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, leaving them available by default.
[w] HF allocation created at the 1979 World Administrative Radio Conference. These are commonly called the "WARC bands". [x] This is not mentioned in the ITU's Table of Frequency Allocations, but individual administrations may make allocations under "Article 4.4". ITU Radio Regulations.. See the appropriate Wiki page for further information. [y] 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.
See also: Radio spectrum, Electromagnetic spectrum