Shortwave bands are frequency allocations for use within the high frequency radio spectrum. They are the primary medium for applications such as marine communication, international broadcasting, and worldwide amateur radio activity because they take advantage of ionospheric skip propagation to send data around the world. The bands are conventionally stated in wavelength as measured by meters. Many bands, most notably the VHF 6 meters band, are notable for their behavior that depends on the season and the level of solar activity. A solid-state, analog shortwave receiver Shortwave radio operates between the frequencies of 3 MHz (3,000 kHz) and 30 MHz (30,000 kHz) [1] and came to be referred to as such in the early days of radio because the wavelengths associated with this frequency range were shorter than... High frequency (HF) radio frequencies are between 3 and 30 MHz. ... Amateur radio station with modern solid-state transceiver featuring LCD display and DSP capabilities Amateur radio, often called ham radio, is a hobby that uses various types of radio broadcasting equipment to communicate with other radio amateurs for public service, recreation and self-training. ... The wavelength is the distance between repeating units of a wave pattern. ... Very high frequency (VHF) is the radio frequency range from 30 MHz to 300 MHz. ... 6 Meters is a popular amateur radio band. ...

The "11-meter" (27 MHz) band is the most significant location allocated by most countries for Citizen's Band service (as well as some early cordless phones), though due to the band's propagation characteristics, which allow long-distance interference with local signals, most land mobile radio activity has moved to VHF or UHF, and most cordless phone activity is also in UHF or higher. A typical mobile citizens band radio Citizens band radio (CB) is, in the United States, a system of short distance radio communication between individuals on a selection of 40 channels within the single 27 MHz (11 meter) band. ... A portable phone or cordless phone is a wireless telephone which is associated with a fixed telephone landline (POTS) and can only be operated close to (typically less than 100 metres of) its base station, such as in and around the house. ... Very high frequency (VHF) is the radio frequency range from 30 MHz to 300 MHz. ... Ultra high frequency (UHF) designates a range (band) of electromagnetic waves whose frequency is between 300 MHz and 3. ... Ultra high frequency (UHF) designates a range (band) of electromagnetic waves whose frequency is between 300 MHz and 3. ...

International broadcasting bands

The band frequencies below are derived from multiple sources, and different radios can have different numbers. Most international broadcasters use amplitude modulation with a stepping of 5 kHz between channels; a few use single sideband modulation. Different radios may define the bands differently. Amplitude modulation (AM) is a technique used in electronic communication, most commonly for transmitting information via a radio carrier wave. ... Single-sideband modulation (SSB) is a refinement of the technique of amplitude modulation designed to be more efficient in its use of electrical power and bandwidth. ...

• 11 meters – 25.67–26.10 MHz – Very little broadcasting activity in this band. Day reception tends to be poor, night reception nonexistent. This band could be used for daytime 'single hop' regional coverage, but very few broadcast transmitters and antennas function in this band. Digital Radio Mondiale has proposed that this band be used for local digital shortwave broadcasts and conducted an extensive test of the concept in Mexico City in 2005. [1] Not to be confused with the Citizen's Band 11-meter allocation, which in most countries runs from 26.965 MHz to 27.405 MHz.
• 13 meters – 21.45–21.85 MHz – Somewhat shaky day reception, very little night. Similar case to 11 metres, but long distance daytime broadcasting keeps this band humming in the Asia-Pacific region.
• 15 meters – 18.90–19.02 MHz – Seldom used.
• 16 meters – 17.48–17.90 MHz – Day reception good, night reception varies seasonally, with summer being the best.
• 19 meters –15.00–15.825 MHz – Day reception good, night reception variable, best during summer. Time stations such as WWV are clustered around 15 MHz.
• 22 meters – 13.57–13.87 MHz – Similar to 19 meters; best in summer.
• 25 meters – 11.50–12.16 MHz – Generally best during summer; said to be ideal during the period before and after sunset.
• 31 meters – 9250–9995 kHz – Good year-round night band; seasonal during the day, with best reception in winter. Time stations are clustered around 10 MHz.
• 41 meters – 7100–7600 kHz – Reception varies by region – reasonably good night reception, but few transmitters in this band are targeted to North America.
• 49 meters – 5800–6300 kHz – Good year-round night band; daytime reception is lacking.
• 60 meters – 4400–5100 kHz – Mostly used locally in tropical regions, though usable at night. Time stations are clustered around 5000 kHz.
• 75 meters – 3900–4050 kHz – Mostly used in Eastern Hemisphere, not widely received in the Americas.
• 90 meters – 3200–3400 kHz – Mostly used locally in tropical regions, with limited long-distance reception at night.
• 120 meters – 2300–2495 kHz – Mostly used locally in tropical regions, with time stations clustered around 2500 kHz. Not technically a shortwave band; resides in the upper reaches of the mediumwave band.

Digital Radio Mondiale (DRM) is a set of digital audio broadcasting technologies designed to work over the bands currently used for AM broadcast, particularly shortwave. ... Nickname: Motto: Ciudad en movimiento Location of Mexico City in central Mexico Coordinates: , Country Mexico Federal entity Federal District Boroughs The 16 delegaciones Founded c. ... // Digital Radio Mondiale conducted an extensive test of using the 11 meter (26 MHz) shortwave band for local digital shortwave radio broadcasts in Mexico City during July. ... A typical mobile citizens band radio Citizens band radio (CB) is, in the United States, a system of short distance radio communication between individuals on a selection of 40 channels within the single 27 MHz (11 meter) band. ... WWV is the callsign of NISTs shortwave radio station located in Fort Collins, Colorado. ... Mediumwave radio transmissions serves as the most common band for broadcasting. ...

Amateur HF bands

The following band allocations are the standard allocations used by the American Radio Relay League and the United States Federal Communications Commission. Consult your local regulatory body for further information; in particular, the 60-meter, 30-meter, and WARC (17 and 12 meter) bands may not be available in your home country. The ARRL Logo. ... The FCCs official seal. ...

• 6 meters – 50–54 MHz – not actually a shortwave band but the lowest VHF band available to amateur operators, 6m is notable for its unusual long-range propagation characteristics largely mediated by solar weather. 6m has useful short-range groundwave propagation characteristics. The wavelength is well-suited to antenna experimentation, as a 1/2 wavelength dipole is 9.8ft (3m) tip-to-tip. Known as the "magic band", DXing on the band is largely done as a technical challenge. A simple antenna and modest power (5 to 10 Watts) are sufficient for long-range communication when the band opens, thus earning its nickname "magic band". Listed here because it is commonly included on HF amateur sets.
• 10 meters – 28–29.7 MHz – Best activity is during solar maximum; during periods of moderate solar activity the best activity is found at low latitudes. The band offers useful short- to medium-range groundwave propation, day or night. Also the site of frequent illegal unlicensed operation ("bootlegging") and freeband activity by operators using modified Citizen's Band equipment.
• 12 meters – 24.89–24.99 MHz – Mostly useful during daytime, but opens up for DX activity at night during solar maximum. 12 meters is a WARC band.
• 15 meters – 21–21.45 MHz – Most useful during solar maximum, and generally a daytime band.
• 17 meters – 18.068–18.168 MHz – Similar to 20m, but more sensitive to solar conditions. By unofficial agreement, this band is not used for amateur contesting, which makes it a fairly quiet place. It is often used for extended, informal chats known as "ragchews." 17 meters is a WARC band.
• 20 meters – 14.0–14.35 MHz – Considered the most popular DX band; usually most popular during daytime. QRP operators recognize 14.060 MHz as their primary calling frequency in that band. Users of the PSK31 data mode tend to congregate around 14.071 MHz. Analog SSTV activity is centered around 14.230 MHz.
• 30 meters – 10.1–10.15 MHz – a very narrow band, which is shared with non-amateur services. It is recommended that only Morse Code and data transmissions be used here, and in some countries amateur voice transmission is actually prohibited. Not released for amateur use in a small number of countries such as Oman and Thailand. Due to its location in the centre of the shortwave spectrum, provides significant opportunities for long-distance communication at all points of the solar cycle. 30 meters is a WARC band.
• 40 meters – 7.0–7.3 MHz – Considered the most reliable all-season DX band, and most popular at night, and extremely useful for medium distance contacts during the day. Much of this band is shared with broadcasters, and in most countries only the bottom 100 kHz or 200 kHz are available to amateurs.
• 60 meters – 5 MHz region – A relatively new allocation and only available in a small number of countries such as the United States, United Kingdom, Norway and Iceland. In most countries, the allocation is channelized, and in the USA it is mandatory to operate in upper sideband mode. Amateur equipment made in Japan or China often does not support this allocation, since it is not available in those countries.
• 80 meters – 3500–4000 kHz – Best at night, with significant daytime signal absorption. Works best in winter due to atmospheric noise in summer. 80m phone operators have a reputation for rowdiness similar to CB operators. Only countries in the Americas and few others have access to all of this band, in other parts of the world amateurs are limited to the bottom 300 kHz or less. The upper end of the subband from 3600–4000 kHz, which permits use of single-sideband voice, is often referred to 75 meters.
• 160 meters – 1800–2000 kHz – Not a shortwave but a mediumwave band, and often taken up as a technical challenge in a manner similar to 6m. Most useful at night, though notoriously noisy. In many locations, a separate specialized receive-only antenna (such as a shielded loop) is necessary for successful operation on the band. Also known as the "top band" and the "Gentlemen's Band", in apparent contrast to the supposedly freewheeling 80m allocation. Allocations in this band vary widely from country to country.

6 Meters is a popular amateur radio band. ... Very high frequency (VHF) is the radio frequency range from 30 MHz to 300 MHz. ... It has been suggested that DX station be merged into this article or section. ... The 10 meter amateur radio band is the highest of the High Frequency or HF bands. ... Solar maximum or solar max is the period of greatest solar activity in the solar cycle of the sun. ... The term Pirate Radio usually refers to illegal or unregulated radio transmission. ... A typical mobile citizens band radio Citizens band radio (CB) is, in the United States, a system of short distance radio communication between individuals on a selection of 40 channels within the single 27 MHz (11 meter) band. ... It has been suggested that DX station be merged into this article or section. ... The WARC bands are 3 frequency ranges used by Amateur radio enthusiasts. ... Shortwave bands are frequency allocations for use within the high frequency radio spectrum. ... The WARC bands are 3 frequency ranges used by Amateur radio enthusiasts. ... In amateur radio, QRP operation means transmitting at reduced power levels. ... PSK31 or Phase Shift Keying, 31 Baud is a digital radio modulation mode, used primarily in the amateur radio field. ... SSTV transmissions often include station call signs, RST reception reports, and radio amateur jargon. ... 1922 Chart of the Morse Code Letters and Numerals Morse code is a method for transmitting telegraphic information, using standardized sequences of short and long elements to represent the letters, numerals, punctuation and special characters of a message. ... The WARC bands are 3 frequency ranges used by Amateur radio enthusiasts. ... This article needs a complete rewrite for the reasons listed on the talk page. ... In radio communications, a sideband is a band of frequencies higher than or lower than the carrier frequency, containing energy as a result of the modulation process. ... This article needs a complete rewrite for the reasons listed on the talk page. ... At just above the AM Broadcast band, 160 meters is the lowest radio frequency band alloted for use by Amateur Radio operators. ... Mediumwave radio transmissions serves as the most common band for broadcasting. ...

Marine and land mobile allocations

The international maritime distress frequency is 2182 kHz; formerly 500 kHz was reserved for Morse Code distress signals, but this frequency allocation has been discarded in favor of systems such as GMDSS and Inmarsat. As mentioned above, most countries that have HF Citizen's Band allocations allocate 40 channels between 26.965 MHz to 27.405 MHz, in 10 kHz steps. The radio frequency of 2182 kilohertz (kHz) is the international calling and distress frequency for voice maritime communication (radio telephony) on the marine MF bands. ... For most of the 20th century, the radio frequency 500 kHz (known as 600 meters or 500 kc for most of the century, before kilohertz replaced kilocycle) was the international calling and distress frequency for ships on the high seas. ... The Global Maritime Distress Safety System (GMDSS) is an internationally-agreed set of safety procedures and types of equipment used to increase safety and make it easier to rescue distressed ships, boats and aircraft. ... Inmarsat is an international telecommunications company founded in 1979, originally as an intergovernmental organization. ...

Military HF allocation

In the US and Canada, as well as the Americas (ITU Region 2) as a whole, there are no pre-designated HF allocations for military use.

Similar rules exist in Western and Eastern Europe, where it has become necessary for European amateurs to police the bands due to overcrowding. Most military HF band incursions into the HF Ham bands occur in Europe or Africa.

Since the end of the Cold War, specific military HF allocations have gradually disappeared from the HF bands -- except for Africa and some parts of Asia.

In Australia, the military shares the HF bands with civilian users -- this is mainly due to low population density and relative underuse of the HF bands.

The military in the Americas (as well as in Australia) has tended to use the civilian fixed, maritime mobile, and aeronautical mobile allocations on an ad-hoc (non-interference) basis.

Industrial/Scientific/Medical (ISM) and other HF allocations

Above 10 MHz there are numerous frequencies set aside for Radio Astronomy, Space Research (FCC terminology), and standard frequency and time services. The Very Large Array, a radio interferometer in New Mexico, USA Radio astronomy is a subfield of astronomy that studies celestial objects in the radio frequency portion of the electromagnetic spectrum. ...

RF diathermy equipment uses 27.12MHz to effect heating of bulk materials or adhesives for the purpose of drying or increasing the cure rate. The industrial use of the frequency was one of the motivations to permit widespread use by the citizenry of the 11m band for CB Radio. Citizens band radio (CB) is, in the United States, a system of short distance radio communication between individuals on a selection of 40 channels within the single 27 MHz (11 meter) band. ...

About a dozen narrow or "sliver" allocations for ISM exist throughout the radio spectrum. See ISM band for more information. The industrial, scientific and medical (ISM) radio bands were originally reserved internationally for non-commercial use of RF electromagnetic fields for industrial, scientific and medical purposes. ...

These allocations are perhaps the smallest in the HF band, with respect to national HF allocations.

See also

• Shortwave and high frequency (HF)
• International broadcasting

A solid-state, analog shortwave receiver Shortwave radio operates between the frequencies of 3 MHz (3,000 kHz) and 30 MHz (30,000 kHz) [1] and came to be referred to as such in the early days of radio because the wavelengths associated with this frequency range were shorter than... High frequency (HF) radio frequencies are between 3 and 30 MHz. ... International broadcasting is broadcasting deliberately aimed at a foreign, rather than a domestic, audience. ...

External links

• American Radio Relay League -- the United States lobbying body for amateur radio and the body responsible for the ARRL Handbook
• Radio Amateurs of Canada -- Canada's National Amateur Radio Society
• Passport to World Band Radio
• World Radio and Television Handbook
• SWDXER ¨The SWDXER¨ - with general SWL information and radio antenna tips.
• EiBi & DX - Complete list of International Broadcasting Stations worldwide, frequently updated.