15-meter band
A shortwave band for long-distance communication via F-2 layer reflection.
The 15-meter band, spanning 21 to 21.45 MHz in the shortwave spectrum, is an amateur radio allocation used for long-distance communication in nearly every country. Its waves travel mainly by bouncing off the ionosphere's F-2 layer, making intercontinental contacts most reliable during daylight hours, particularly around solar maxima. However, the band also supports long-range links without requiring high-power gear even when conditions are less than ideal. Because 15 meters is harmonically related to the 40-meter band, antennas built for 40 meters often work on 15 meters as well.
The band was created at the 1947 International Radio Conference in Atlantic City, partly to offset amateur radio's loss of the 160-meter band due to wartime LORAN use. In the United States, it opened to amateurs for CW-only operation on May 1, 1952. Telephony was authorized above 21.25 MHz, and Novice CW between 21.100 and 21.250 MHz, on March 28, 1953.
- Frequency range
- 21 to 21.45 MHz
- Designated by
- 1947 International Radio Conference of Atlantic City
- Opened for cw in us
- May 1, 1952
- Telephony authorized above 21.25 mhz in
- March 28, 1953
- Novice cw authorized between 21.100 and
- March 28, 1953
- Japan allocation changed
- September 25, 2023
Lore & Background
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.
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. In Canada, the Radio Amateurs of Canada offers a bandplan as a recommendation for use by radio amateurs, but it does not have the force of law and should only be considered a suggestion or guideline. Japan's allocation changed on September 25, 2023.
Reader's Guide
The 15-meter band is notable for its ability to support intercontinental communication during daylight hours, particularly near solar maxima, yet it also permits long-distance contacts without high-power station equipment outside such ideal windows. Its designation by the 1947 International Radio Conference of Atlantic City addressed the loss of the 160-meter band due to LORAN during World War II. The band's propagation via the F-2 layer of the ionosphere makes it a reliable choice for amateur operators seeking long-distance contacts. The harmonic relationship with the 40-meter band allows practical antenna reuse, simplifying station setup. In the United States, the band opened for CW in 1952 and for telephony and Novice CW in 1953. Canada's bandplan is a non-binding recommendation, while Japan updated its allocation in 2023. The band remains widely permitted for amateur use across nearly all countries, supporting its ongoing significance in the amateur radio community.
Did You Know?
- The 15-meter band spans 21 to 21.45 MHz.
- In the United States, telephony operations were authorized above 21.25 MHz on March 28, 1953.
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