15 METERS
In telecommunications, '15 meters' is a shortwave radio band used by amateur radio operators. The band is located at 21 MHz, and most countries permit amateur radio activity on at least the lower portion of the band.
The '15 meter' or '21 MHz' band is a core amateur radio frequency band, which spans 21 to 21.45 MHz and is allocated to radio amateurs as primary users worldwide. 15 meters is considered a DX band, most useful for inter-continental communication during daylight hours, especially in years close to the solar maximum, since the 15 meter wavelength propagates primarily via reflection by the F-2 layer.
Because the frequency is an odd-order harmonic of the 40 meter amateur band, it is possible to obtain a close impedance match using an antenna cut for 40 meters on 15 meters, as well. Usually, though, users of the 15 meter band employ rotatable, multi-element directional antennas or "beams" to improve their communications with the particular area of the world they wish to reach.
Shortwave bands
★ ARRLWeb: US Amateur Bands
★ ARRLWeb: ARRL Band Plans
★ UK Amateur Radio Bandplans Band Plans
★ Ham Radio QRP
★ IARU Region 1 Bandplan
★ IARU Region 2 Bandplan
★ IARU Region 3 Bandplan
| Contents |
| Summary |
| Frequency allocation |
| United States |
| Key |
| Band plan |
| United States |
| See also |
| References |
Summary
The '15 meter' or '21 MHz' band is a core amateur radio frequency band, which spans 21 to 21.45 MHz and is allocated to radio amateurs as primary users worldwide. 15 meters is considered a DX band, most useful for inter-continental communication during daylight hours, especially in years close to the solar maximum, since the 15 meter wavelength propagates primarily via reflection by the F-2 layer.
Because the frequency is an odd-order harmonic of the 40 meter amateur band, it is possible to obtain a close impedance match using an antenna cut for 40 meters on 15 meters, as well. Usually, though, users of the 15 meter band employ rotatable, multi-element directional antennas or "beams" to improve their communications with the particular area of the world they wish to reach.
Frequency allocation
United States
| 15 Meters | 21000 – 21025 | 21025 – 21200 | 21200 – 21225 | 21225 – 21275 | 21275 – 21450 |
|---|---|---|---|---|---|
| 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) |
Band plan
United States
| 21.070-21.110 | RTTY, data (US: < 1 KHz bandwidth) |
| 21.340 | SSTV |
See also
Shortwave bands
References
★ ARRLWeb: US Amateur Bands
★ ARRLWeb: ARRL Band Plans
★ UK Amateur Radio Bandplans Band Plans
★ Ham Radio QRP
★ IARU Region 1 Bandplan
★ IARU Region 2 Bandplan
★ IARU Region 3 Bandplan
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