The World Administrative Radio Conference (WARC) bands are three portions of the shortwave radio spectrum used by licensed and/or certified amateur radio operators. They consist of 30 meters (10.1–10.15 MHz), 17 meters (18.068–18.168 MHz), and 12 meters (24.89–24.99 MHz).[1][2] They were named after the World Administrative Radio Conference, which in 1979 created a worldwide allocation of these bands for amateur use. The bands were opened for use in the early 1980s. Due to their relatively small bandwidth of 100 kHz or less, there is a gentlemen's agreement that the WARC bands may not be used for general contesting. This agreement has been codified in official recommendations, such as the IARU Region 1 HF Manager's Handbook, which states: "Contest activity shall not take place on the 5, 10, 18, and 24 MHz bands."[3]
Non-contesting radio amateurs are recommended to use the contest-free HF bands (30, 17, and 12m) during the largest international contests.[4]
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.[7]
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.
Throughout most of the world, the 30-meter band generally cannot be used for "phone" (voice) communications. SSB may be used during emergencies involving the immediate safety of life and property and only by stations actually involved in the handling of emergency traffic.
However, a part of Region 1 is permitted to use phone at certain times.[10] The band segment 10.12 to 10.14 may only be used for SSB transmissions in the area of Africa south of the equator during local daylight hours.
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.
Australia (VK, region 3) has a unique set of privileges on 30 meters which allows voice operation on a section of the band for advanced license holders. The digital segment is 10.13-10.15 MHz. The current band plan has telephony from 10.12–10.135 MHz, with CW only below 10.12. These are WIA [13] recommendations only as ACMA does not restrict Australian amateurs' modes within HF allocations beyond requiring less than 8 kHz occupied bandwidth per channel below 28 MHz.
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. [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 many individual administrations have commonly adopted this allocation under "Article 4.4". [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.
