The 40-meter or 7-MHz band is an

amateur radio Amateur radio, also known as ham radio, is the use of the radio frequency radio spectrum, spectrum for purposes of non-commercial exchange of messages, wireless experimentation, self-training, private recreation, radiosport, contesting, and emer ...

frequency band, spanning 7.000-7.300

MHz The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), often described as being equivalent to one event (or cycle) per second. The hertz is an SI derived unit whose formal expression in terms of SI base u ...

in ITU Region 2, and 7.000-7.200 MHz in Regions 1 & 3. It is allocated to radio amateurs worldwide on a primary basis; however, only 7.000-7.200 MHz is exclusively allocated to amateur radio worldwide. Shortwave broadcasters and land mobile users also have primary allocations in some countries, and amateur stations must share the band with these users. 40-meters is considered one of the most reliable all-season long-distance communication ( DX) and intercontinental bands.

History

The 40-meter band was made available to amateurs in the United States by the Third National Radio Conference on October 10, 1924,"Frequency or wave band allocations"
''Recommendations for Regulation of Radio Adopted by the Third National Radio Conference'' (October 6–10, 1924), page 15. and allocated on a worldwide basis by th
International Radiotelegraph Conference
in Washington, D.C., on October 4, 1927. For many years, the portion of the band from 7.100 to 7.300 MHz was allocated to short wave broadcast stations outside the Americas, and was not available to radio amateurs outside of ITU Region 2. At the World Radio Conference WRC-03 in 2003, it was agreed that the broadcast stations would move out of the section 7.100–7.200 MHz on 29 March 2009 and that portion would become a worldwide exclusive amateur allocation afterwards. Releasing the remaining 100 kHz of the band to amateurs at a later date is an IARU aim for future conferences.

Radio propagation characteristics

This band supports both long distance (DX) and intercontinental communications between late afternoon and a few hours after sunrise, and local-to-medium distance NVIS communication during most daylight hours. With its unique combination of intracontinental and intercontinental communications possibilities, 40-meters is considered a key band in building a winning HF contesting score during any part of the sunspot cycle.

Usage

The band is most useful for long distance (DX) communications and intercontinental communication (ranges greater than 1,500 km or 1,000 miles) for one or two hours before sunset, during the night and for one or two hours after sunrise. It is extremely useful for local-to-medium distance communications out to a range of or more, depending on conditions, during the day. In higher latitudes, daytime intercontinental communication is also possible during the short days of winter, for example a good path often opens between

Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

and northern

Europe Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...

in the hours leading up to European midday from late November through late January, with a long path opening to the west coast of the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

and

Canada Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of coun ...

after midday. Due to the 24-hour nature of the band, the wide variety of ranges that can be spanned with it, and its shared nature, it tends to be extremely crowded, and interference from other amateurs and broadcasters often limits available and usable frequencies on this band.. In recent years amateurs in east and southeast

Asia Asia ( , ) is the largest continent in the world by both land area and population. It covers an area of more than 44 million square kilometres, about 30% of Earth's total land area and 8% of Earth's total surface area. The continent, which ...

have also suffered severe interference from illegal users.

Band plans

In most jurisdictions the subdivision of the band into different operating modes is according to informal convention rather than legal requirement.

IARU Region 1

Europe, Africa, Middle East and Northern Asia

IARU Region 2

The Americas

IARU Region 3

Asia-Pacific

Japan

Changed on September 25, 2023. Immediately after the change, stations that ignore international practice and operate SSB on lower frequencies appeared.

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 (effective 2023-06-01) 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.

United States

Key

References

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