40 meters
Encyclopedia
The 40-meter or 7-MHz band is an amateur radio
Amateur radio
Amateur radio is the use of designated radio frequency spectrum for purposes of private recreation, non-commercial exchange of messages, wireless experimentation, self-training, and emergency communication...

 frequency band, spanning 7000 to 7300 kilohertz (7200 kHz in ITU Region 1), allocated to radio amateurs in all countries worldwide.

40 meters is considered one of the most reliable all-season DX
DXing
DXing is the hobby of tuning in and identifying distant radio or television signals, or making two way radio contact with distant stations in amateur radio, citizens' band radio or other two way radio communications. Many DXers also attempt to receive written verifications of reception from the...

 bands.

Radio propagation characteristics

This band supports both long distance (DX) communications between late afternoon and a few hours after sunrise, and short distance NVIS
Near Vertical Incidence Skywave
Near Vertical Incidence Skywave, or NVIS, is a radio-wave propagation method that provides usable signals in the range between groundwave and skywave distances . It is used mainly for military and paramilitary communications and by radio amateurs...

 contacts during most daylight hours.

With its unique combination of intra- and intercontinental communications possibilities, 40 meters is considered a key band in building a winning HF contesting
Contesting
Contesting is a competitive activity pursued by amateur radio operators. In a contest, an amateur radio station, which may be operated by an individual or a team, seeks to contact as many other amateur radio stations as possible in a given period of time and exchange information...

 score during any part of the sunspot cycle
Solar variation
Solar variation is the change in the amount of radiation emitted by the Sun and in its spectral distribution over years to millennia. These variations have periodic components, the main one being the approximately 11-year solar cycle . The changes also have aperiodic fluctuations...

.

Usage

The band is most useful for inter-continental communication for one or two hours before sunset, during the night and for one or two hours after sunrise. It is extremely useful for short to medium distance contacts from local contacts out to a range of 500–1500 km 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
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

 and northern Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

 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
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 and Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...

 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 can be a serious limiting factor. In recent years amateurs in east and southeast Asia
Asia
Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...

 have also suffered severe interference from illegal users.

Frequency allocation

The 40-meter band was made available to amateurs in the United States by the Third National Radio Conference on October 10, 1924 and allocated on a worldwide basis by the International Radiotelegraph Conference in Washington, D.C., on October 4, 1927.

For many years the portion of the band from 7100–7300 kilohertz has been allocated to short wave broadcasters outside the Americas and not available to radio amateurs outside ITU
Itu
Itu is an old and historic municipality in the state of São Paulo in Brazil. The population in 2009 was 157,384 and the area is 641.68 km². The elevation is 583 m. This place name comes from the Tupi language, meaning big waterfall. Itu is linked with the highway numbered the SP-75 and are flowed...

 Region 2. At the World Radio Conference
World Radiocommunication Conference
World Radiocommunication Conference is organized by ITU to review, and, as necessary, revise the Radio Regulations, the international treaty governing the use of the radio-frequency spectrum and the geostationary-satellite and non-geostationary-satellite orbits. It is held every three to four years...

 WRC-03 in 2003 it was agreed that the broadcast stations would move out of the section 7100–7200 kilohertz on 29 March 2009 and that portion would become a worldwide exclusive amateur allocation afterwards. Discussions on releasing the remaining 100 kHz of the band to amateurs at a later date will continue in future conferences.

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

Japan

License class 7.000–7.025 7.030–7.100
All classes

United Kingdom

License class 7.000–7.035 7.045–7.200
All classes

IARU Region 1

40 meters 7000 7035 7035 7040 7040 7043 7043 7100 7100 7200
IARU Region 1

Canada

Canada is part of region 2 and as such is subject to the IARU band plan. Radio Amateurs of Canada
Radio Amateurs of Canada
Radio Amateurs of Canada , known in French as Radio Amateurs du Canada, is a member-based, non-profit organization of amateur radio enthusiasts in 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.
License class 7.000–7.035 7.035-7.040 7.040-7.050 7.050-7.080 7.080-7.125 7.125-7.165 7.165-7.175 7.175–7.300
Basic(+), Advanced

United States

U.S. license class 7.000–7.025 7.025–7.125 7.125–7.175 7.175–7.300
Novice / Technician
General
Advanced
Extra

Key

= CW
Continuous wave
A continuous wave or continuous waveform is an electromagnetic wave of constant amplitude and frequency; and in mathematical analysis, of infinite duration. Continuous wave is also the name given to an early method of radio transmission, in which a carrier wave is switched on and off...

, RTTY
Radioteletype
Radioteletype is a telecommunications system consisting originally of two or more electromechanical teleprinters in different locations, later superseded by personal computers running software to emulate teleprinters, connected by radio rather than a wired link.The term radioteletype is used to...

 and data (US: < 1 kHz bandwidth)
= CW
Continuous wave
A continuous wave or continuous waveform is an electromagnetic wave of constant amplitude and frequency; and in mathematical analysis, of infinite duration. Continuous wave is also the name given to an early method of radio transmission, in which a carrier wave is switched on and off...

, RTTY
Radioteletype
Radioteletype is a telecommunications system consisting originally of two or more electromechanical teleprinters in different locations, later superseded by personal computers running software to emulate teleprinters, connected by radio rather than a wired link.The term radioteletype is used to...

, data, MCW
Modulated continuous wave
Modulated continuous wave is defined by the Federal Communications Commission in 47 CFR §97.3 as "Tone-modulated international Morse code telegraphy emissions having designators with A, C, D, F, G, H or R as the first symbol; 2 as the second symbol; A or B as the third symbol." See Types of radio...

, test, phone and image
= CW
Continuous wave
A continuous wave or continuous waveform is an electromagnetic wave of constant amplitude and frequency; and in mathematical analysis, of infinite duration. Continuous wave is also the name given to an early method of radio transmission, in which a carrier wave is switched on and off...

, phone and image
= CW
Continuous wave
A continuous wave or continuous waveform is an electromagnetic wave of constant amplitude and frequency; and in mathematical analysis, of infinite duration. Continuous wave is also the name given to an early method of radio transmission, in which a carrier wave is switched on and off...

 and SSB
Single-sideband modulation
Single-sideband modulation or Single-sideband suppressed-carrier is a refinement of amplitude modulation that more efficiently uses electrical power and bandwidth....

 phone
= CW
Continuous wave
A continuous wave or continuous waveform is an electromagnetic wave of constant amplitude and frequency; and in mathematical analysis, of infinite duration. Continuous wave is also the name given to an early method of radio transmission, in which a carrier wave is switched on and off...

, RTTY
Radioteletype
Radioteletype is a telecommunications system consisting originally of two or more electromechanical teleprinters in different locations, later superseded by personal computers running software to emulate teleprinters, connected by radio rather than a wired link.The term radioteletype is used to...

, data, phone and image
= CW
Continuous wave
A continuous wave or continuous waveform is an electromagnetic wave of constant amplitude and frequency; and in mathematical analysis, of infinite duration. Continuous wave is also the name given to an early method of radio transmission, in which a carrier wave is switched on and off...

only (US Novice/Technician: 200 W PEP maximum TPO)
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