Amateur radio frequency allocation is done by national telecommunications authorities. Globally, the International Telecommunication Union (ITU) oversees how much radio spectrum is set aside for amateur radio transmissions. Individual amateur stations are free to use any frequency within authorized frequency ranges; authorized bands may vary by the class of the station license.
Radio amateurs use a variety of transmission modes, including Morse code, radioteletype, data, and voice. Specific frequency allocations vary from country to country and between ITU regions as specified in the current ITU HF frequency allocations for amateur radio. The modes and types of allocations within each range of frequencies is called a bandplan, and may be set by international agreements, national regulations, or agreements between amateur radio operators.
Local authorities regulate amateur usage of radio bands. Some bands may not be available or may have restrictions on usage in certain countries or regions. International agreements assign amateur radio bands which differ by region.[1][2]
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While "line of sight" propagation is a primary factor for range calculation, much of the interest in the bands above HF comes from use of other propagation modes. A VHF signal transmitted from a hand-held portable will typically travel about 5-10 km depending on terrain. With a low power home station and a simple antenna, range would be around 50 km. With a large antenna system like a long yagi, and higher power (typically 100 or more watts) contacts of around 1000 km using the CW (Morse code) and SSB (Single Side Band) modes are common. Ham operators seek to exploit the limits of the frequencies usual characteristics looking to learn, understand and experiment with the limits of these enhanced propagation modes. They also seek to take advantage of "band openings" where due to natural occurrences in the atmosphere and ionosphere radio transmission distances can extend well over their normal range. Many hams listen for hours hoping to take advantage of these occasional extended propagation 'openings'.
Some openings are caused by islands of intense ionization of the upper atmosphere known as the E Layer ionosphere. These islands of intense ionization are called 'Sporadic E' and result in erratic but often strong propagation characteristics on the 'low band' VHF radio frequencies. The 6 meter amateur band falls into this category, often called 'The Magic Band', 6 meters will often 'open up' from one small area into another small geographic area 1000–1700 km away during the spring and early summer months. This phenomenon occurs during the fall months, although not as often.
Band openings are sometimes caused by a weather phenomenon known as a tropospheric 'inversion', where a stagnant high pressure area causes alternating stratified layers of warm and cold air generally trapping the colder air beneath. This may make for smoggy/foggy days but it also causes VHF/UHF radio transmissions to travel or duct along the boundaries of these warm/cold atmospheric layers. Radio signals have been known to travel hundreds, even thousands of kilometers due to these unique weather conditions. For example: The longest distance reported contact due to tropospheric refraction on 2 meters is 4754 km between Hawaii and a ship south of Mexico. There were reports of the reception of one way signals from Réunion to Western Australia, a distance of more than 6000 km.[3]
F2 and TE band openings from other ionospheric reflection/refraction modes, or sky-wave propagation as it is known can also occasionally occur on the low band VHF frequencies of 6, 4 and very rarely on 2 meters (high band VHF) during extreme peaks in the 11 year sunspot cycle. The longest terrestrial contact ever reported on 2 meters (146mhz) was between a station in Italy and a station in South Africa, a distance of 7784 km, using anomalous enhancement (TE) of the ionosphere over the geomagnetic equator. This enhancement is known as TE, or trans-equatorial propagation and (usually) occurs at latitudes 2500–3000 km within either side of the equator.[4]
Other less frequently used modes are tropospheric scatter, moon bounce and Aurora Borealis (Northern Lights) and amateur radio satellite.
Using relatively high power, usually over 1000 watts and a high gain antenna, 'Tropo-scatter' (water droplets and dust particles can refract a VHF/UHF signal over the horizon) propagation will give marginal enhanced over-the-horizon VHF and UHF communications of up to 300 miles (450 km). During the 1970s commercial 'scatter site' operators using huge parabolic antennas and high power used this mode successfully for telephone communications services into remote Alaska and Canadian northern communities. Satellite, buried fiber optic and terrestrial microwave access have relegated Tropo-scatter to the history books. Because of high cost and complexity this mode is usually out of reach for the average amateur radio operator.
Moon Bounce: Using moderately high power (more than 500 watts) and a fairly large antenna, amateurs do successfully communicate by bouncing their signals off the surface of the moon. Signals are weak and distorted because the moon's surface is very rocky and irregular. Moon bounce communications use either digital modes, for example JT65, designed for working with weak signals, or CW Morse code.
Aurora: An intense solar storm causing aurora borealis (Northern Lights) will also provide occasional HF-low band 6 meter VHF propagation enhancement. Aurora only occasionally affects 2 meters. Signals are often distorted and on the lower frequencies give a curious 'watery sound' to normally propagated HF signals. Peak signals usually come from the north, even though the station you are talking to is east or west of you. Most noticeable in the northern latitudes above 45 degrees.
Satellite: Not really a propagation mode, but an active repeater system. Satellites have been highly successful in providing VHF/UHF/SHF users 'propagation' beyond the horizon. The ISS which has amateur radio repeaters and radio locations services on board is a good example. Amateurs have also sponsored the launch of dozens of communications satellites since the 1970s. These satellites are usually known as OSCARs (Orbiting Satellite Carrying Amateur Radio).
Amateur television (ATV) is the hobby of transmitting broadcast- compatible video and audio by amateur radio. It also includes the study and building of such transmitters and receivers and the propagation between these two.
In NTSC countries, ATV operation requires the ability to use a 6 MHz wide channel. All bands at VHF or lower are less than 6 MHz wide, so ATV operation is confined to UHF and up. Bandwidth requirements will vary from this for PAL and SECAM transmissions.
ATV operation in the 70 cm band is particularly popular, because the signals can be received on any cable-ready television. Operation in the 33 cm and 23 cm bands is easily augmented by the availability of various varieties of consumer-grade wireless video devices that exist and operate in unlicensed frequencies coincident to these bands.
Repeater ATV operation requires specially-equipped repeaters.
See also slow-scan television.
Historically, amateur stations have rarely been allowed to operate on frequencies lower than the medium-wave broadcast band, but in recent times, as the historic users of these low frequencies have been vacating the spectrum, limited space has opened up to allow for new amateur radio allocations and special experimental operations. Since the 500 kHz band is no longer used for marine communications, some countries permit experimental amateur radio radiotelegraph operations in that band. The 2200-meter band is available for use in several countries, and the 2007 World Radiocommunication Conference (WRC-07) made it a world wide amateur allocation. Before the introduction of the 2200-meter band in the UK in 1998, operation on the even lower frequency of 73 kHz had been allowed between 1996 and 2003.
ITU Region 1 corresponds to Europe, Russia, Africa and the Middle East. For ITU region 1, Radio Society of Great Britain's band plan will be more definitive (click on the buttons at the bottom of the page).
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The following charts show the voluntary bandplans used by amateurs in Region 1. Unlike the USA, slots for the various transmission modes are not set by the amateur's licence but most users do follow these guidelines.
160 Metres | 1810 1838 | 1838 1840 | 1840 1843 | 1843 2000 | |
---|---|---|---|---|---|
IARU Region 1 | |||||
IARU Region 2 | 1800–1840 | ||||
IARU Region 3 | 1800–1840 | ||||
Note: Region 2 QRP/DX window is 1830-1850 |
80 Metres | 3500 3580 | 3580 3600 | 3600 3620 | 3620 3800 |
---|---|---|---|---|
IARU Region 1 |
60 Metres | 5258.5 | 5278.5 | 5288.5 | 5366.5 | 5371.5 | 5398.5 | 5403.5 | ||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
United Kingdom | FA | FB | FC | FK | FL | FE | FM | ||||||
Note: 60 Meter emissions are limited to UK NoV-endorsed Full licence holders only
in 3 kHz channels with the specified lower frequency limits, 200 watts |
60 Metres | start | 5310.0 | 5335.0 | 5355.0 | 5375.0 | 5403.5 | end | ||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Norway | 5260.0 5250.0 | CW calling | QRP | Digimode | Nat. Call USB | Int. Call USB | 5410.0 5450.0 | ||||||
Note: 60 Meter band in Norway is 5260 – 5410 kHz, in Denmark 5250 – 5450 kHz.
Danish stations have to apply for a special research-license and are limited to 1 kW ERP. Both countries can use VFO/allmode. |
40 Metres | 7000 7040 | 7040 7050 | 7050 7060 | 7060 7100 | 7100 7200 | 7200 7300 | |||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
IARU Region 1 | |||||||||||||
As of March, 2009, 7100-7200 were allocated to Amateur radio on a primary basis by ITU. Yet, there are countries that haven't yet expanded their national Amateur radio service bandplan to cover that portion. In ITU region 2, 7200-7300 is allocated to amateur radio service as secondary. |
30 Metres | 10100 10140 | 10140 10150 |
---|---|---|
IARU Region 1 |
20 Metres | 14000 14070 | 14070 14099 | B | 14101 14350 |
---|---|---|---|---|
IARU Region 1 |
17 Metres | 18068 18095 | 18095 18109 | B | 18111 18168 |
---|---|---|---|---|
IARU Region 1 |
15 Metres | 21000 21070 | 21070 21110 | 21110 21120 | 21120 21149 | B | 21151 21450 |
---|---|---|---|---|---|---|
IARU Region 1 |
12 Metres | 24890 24915 | 24915 24929 | B | 24931 24990 |
---|---|---|---|---|
IARU Region 1 |
10 Metres | 28000 28070 | 28070 28190 | B | 28225 29200 | 29200 29300 | 29300 29510 | 29510 29700 |
---|---|---|---|---|---|---|---|
IARU Region 1 | Satellite D/L |
= CW and data (<200 Hz bandwidth) | |
= CW, RTTY and data (< 500 Hz Bandwidth) | |
= CW, RTTY, data, NO SSB (<2.7 kHz) | |
= CW, phone and image (<3 kHz bandwidth) SECONDARY | |
= CW, phone and image (<3 kHz bandwidth) | |
= CW, data, packet, FM, phone and image (<20 kHz bandwidth) | |
= CW, RTTY, data, test, phone and image | |
= Reserved for satellite downlink | |
= Reserved for beacons |
ITU region 2 consists of the Americas, including Greenland. The frequency allocations for United States hams in ITU Region 2 are:
ITU band | Band name | Frequencies (MHz) | |
---|---|---|---|
Lower end | Upper end | ||
5 - LF | 2200 meters | 135.7 kHz | 137.8 kHz |
6 - MF | 160 meters | 1.8 | 2.0 |
7 - HF | 80 meters | 3.5 | 4.0 |
60 meters | Channelized - 5.332, 5.348, 5.368, 5.373, 5.405 (USB only) | ||
40 meters | 7.0 | 7.3 | |
30 meters | 10.1 | 10.15 | |
20 meters | 14 | 14.35 | |
17 meters | 18.068 | 18.168 | |
15 meters | 21 | 21.45 | |
12 meters | 24.89 | 24.99 | |
10 meters | 28 | 29.7 | |
8 - VHF | 6 meters | 50 | 54 |
2 meters | 144 | 148 | |
1.25 meters | 219 | 220 | |
222 | 225 | ||
9 - UHF | 70 centimeters | 420 | 450 |
33 centimeters | 902 | 928 | |
23 centimeters | 1240 | 1300 | |
13 centimeters | 2300 | 2310 | |
2390 | 2450 | ||
10 - SHF | 9 centimeters | 3300 | 3500 |
5 centimeters | 5650 | 5925 | |
3 centimeters | 10000 | 10500 | |
1.2 centimeters | 24000 | 24250 | |
11 - EHF | 6 millimeters | 47000 | 47200 |
4 millimeters | 75500 | 81000 | |
2.5 millimeters | 119980 | 120020 | |
2 millimeters | 142000 | 149000 | |
1 millimeter | 241000 | 250000 |
The ARRL has a detailed band plan for US hams showing allocations within each band.
RAC has a chart showing the frequencies available to amateurs in Canada.
160 m | 1800–2000 |
---|---|
Canada | |
United States | 1800 2000 |
General, Advanced, Extra |
80 / 75 m | 3500 - 4000 | ||||
---|---|---|---|---|---|
Canada | |||||
United States | 3500 3525 | 3525 3600 | 3600 3700 | 3700 3800 | 3800 4000 |
Novice / Technician | |||||
General | |||||
Advanced | |||||
Extra |
60 m | 5330 - 5406 | |||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
United States | 5330.5 | 5346.5 | 5366.5 | 5371.5 | 5403.5 | |||||||||
General, Advanced, Extra | ||||||||||||||
Note: US licensees operating 60 m are limited to emissions of upper sideband suppressed carrier, 2.8 kHz bandwidth (2K80J3E), 50 watts PEP ERP relative to a 1/2 wave dipole, on the carrier frequencies indicated on this chart |
40 m | 7000 - 7300 | |||
---|---|---|---|---|
Canada | ||||
United States | 7000 7025 | 7025 7125 | 7125 7175 | 7175 7300 |
Novice / Technician | ||||
General | ||||
Advanced | ||||
Extra |
30 m | 10100 10150 |
---|---|
Canada | |
United States | |
Note: US limited to General, Advanced and Extra
licensees; 200 watts PEP |
20 m | 14000 - 14350 | ||||
---|---|---|---|---|---|
Canada | |||||
United States | 14000 14025 | 14025 14150 | 14150 14175 | 14175 14225 | 14225 14350 |
General | |||||
Advanced | |||||
Extra |
17 m | 18068 - 18168 | |
---|---|---|
Canada | ||
United States | 18068 18110 | 18110 18168 |
General, Advanced, Extra |
15 m | 21000 - 21450 | ||||
---|---|---|---|---|---|
Canada | |||||
United States | 21000 21025 | 21025 21200 | 21200 21225 | 21225 21275 | 21275 21450 |
Novice / Technician | |||||
General | |||||
Advanced | |||||
Extra |
12 m | 24890 - 24990 | |
---|---|---|
Canada | ||
United States | 24890 24930 | 24930 24990 |
General, Advanced, Extra |
10 m | 28000 - 29700 | ||
---|---|---|---|
Canada | |||
United States | 28000 28300 | 28300 28500 | 28500 29700 |
Novice / Technician | |||
General, Advanced, Extra | |||
Note: The 10 meter table is one-third scale, relative to the other tables |
= CW, RTTY and data (US: < 1 kHz Bandwidth) | |
= CW, RTTY, data, MCW, phone (AM and SSB) and image (narrow band sstv modes only) | |
= CW, phone and image | |
= CW and SSB phone (US: Novice/Technician 200 watts PEP only) | |
= CW, RTTY, data, phone and image | |
= CW (US: Novice/Technician 200 watts PEP only) | |
= Upper sideband suppressed carrier phone, 2.8 kHz bandwidth (2K80J3E), 50 watts ERP referenced to dipole |
ITU region 3 consists of Australia, New Zealand, the South Pacific, and Asia south of Siberia. The IARU Region 3 Bandplan [5]
The Wireless Institute of Australia has charts for Amateur frequencies for Australia.
The New Zealand Association of Radio Transmitters (NZART) has charts for Amateur frequencies and repeater lists for New Zealand.
The Japanese have charts for Amateur frequencies in Japan
Radio amateurs may engage in satellite and space craft communications; however, the frequencies allowed for such activities are allocated separately from more general use radio amateur bands.
Under the International Telecommunication Union's rules, all amateur radio operations may only occur within 50 kilometres (31 mi) of the Earth's surface. As such, the Amateur Radio Service is not permitted to engage in satellite operations; however, a sister radio service, called the Amateur Satellite Service, exists which allows satellite operations for the same purposes as the Amateur Radio Service. In most countries, an amateur radio license conveys operating privileges in both services, and in practice, the legal distinction between the two services is transparent to the average licensee. The primary reason the two services are separate is to limit the frequencies available for satellite operations. Due to the shared nature of the amateur radio allocations internationally, and the nature of satellites to roam worldwide, the ITU does not consider all amateur radio bands appropriate for satellite operations. Being separate from the Amateur Radio Service, the Amateur Satellite Service receives its own frequency allocations. All the allocations are within amateur radio bands, and with one exception, the allocations are the same in all three ITU regions. Some of the allocations are limited by the ITU in what direction transmissions may be sent (EG: "Earth-to-space" or up-links only).
All amateur satellite operations occur within the allocations tabled below, except for AO-7, which has an up-link from 432.125 MHz to 432.175 MHz.
International amateur satellite frequency allocations | ||||||
---|---|---|---|---|---|---|
Range | Band | Letter1 | Allocation[6] | Preferred sub-bands2 | User status[6] | Notes[6] |
HF | 40 m | 7.000 MHz - 7.100 MHz | Primary | |||
20 m | 14.000 MHz - 14.250 MHz | Primary | ||||
17 m | 18.068 MHz - 18.168 MHz | Primary | Entire amateur radio band | |||
15 m | H | 21.000 MHz - 21.450 MHz | Primary | Entire amateur radio band | ||
12 m | 24.890 MHz - 25.990 MHz | Primary | Entire amateur radio band | |||
10 m | A | 28.000 MHz - 29.700 MHz | 29.300 MHz - 29.510 MHz | Primary | Entire amateur radio band | |
VHF | 2 m | V | 144.000 MHz - 146.000 MHz | 145.800 MHz - 146.000 MHz | Primary | |
UHF | 70 cm | U | 435.000 MHz - 438.000 MHz | NIB3 | ||
23 cm | L | 1.260 GHz - 1.270 GHz | NIB3 | Only uplinks allowed | ||
13 cm | S | 2.400 GHz - 2.450 GHz | 2.400 GHz - 2.403 GHz | NIB3 | ||
SHF | 9 cm | S2 | 3.400 GHz - 3.410 GHz | NIB3 | Not available in ITU region 1. | |
5 cm | C | 5.650 GHz - 5.670 GHz | NIB3 | Only uplinks allowed | ||
5.830 GHz - 5.850 GHz | Secondary | Only downlinks allowed | ||||
3 cm | X | 10.450 GHz - 10.500 GHz | Secondary | |||
1.2 cm | K | 24.000 GHz - 24.050 GHz | Primary | |||
EHF4 | 6 mm | R | 47.000 GHz - 47.200 GHz | Primary | Entire amateur radio band | |
4 mm | 76.000 GHz - 77.500 GHz | Secondary | ||||
77.500 GHz - 78.000 GHz | Primary | |||||
78.000 GHz - 81.000 GHz | Secondary | |||||
2 mm | 134.000 GHz - 136.000 GHz | Primary | Entire amateur radio band | |||
136.000 GHz - 141.000 GHz | Secondary | |||||
1 mm | 241.000 GHz - 248.000 GHz | Secondary | Entire amateur radio band | |||
248.000 GHz - 250.000 GHz | Primary | |||||
1 AMSAT band letters. Not all bands have been assigned a letter by AMSAT. |
Range | Band | ITU Region 1 | ITU Region 2 | ITU Region 3 |
---|---|---|---|---|
LF | 2200 m | 135.7 kHz - 137.8 kHz | ||
MF | 160 m | 1.810 MHz - 1.850 MHz | 1.800 MHz - 2.000 MHz | 1.800 MHz - 2.000 MHz |
HF | 80 / 75 m | 3.500 MHz - 3.800 MHz | 3.500 MHz - 4.000 MHz | 3.500 MHz - 3.900 MHz |
60 m1 | 5.250 MHz - 5.450 MHz | |||
40 m | 7.000 MHz - 7.200 MHz | 7.000 MHz - 7.300 MHz | 7.000 MHz - 7.200 MHz | |
30 m2 | 10.100 MHz - 10.150 MHz | |||
20 m | 14.000 MHz - 14.350 MHz | |||
17 m2 | 18.068 MHz - 18.168 MHz | |||
15 m | 21.000 MHz - 21.450 MHz | |||
12 m2 | 24.890 MHz - 24.990 MHz | |||
10 m | 28.000 MHz - 29.700 MHz | |||
VHF | 6 m | 50.000 MHz - 52.000 MHz1 | 50.000 MHz - 54.000 MHz | 50.000 MHz - 54.000 MHz |
4 m1 | 70.000 MHz - 70.500 MHz | |||
2 m | 144.000 MHz - 146.000 MHz | 144.000 MHz - 148.000 MHz | 144.000 MHz - 148.000 MHz | |
1.25 m | 220.000 MHz - 225.000 MHz | |||
UHF | 70 cm | 430.000 MHz - 440.000 MHz | 420.000 MHz - 450.000 MHz3 | 420.000 MHz - 450.000 MHz3 |
33 cm | 902.000 MHz - 928.000 MHz | |||
23 cm | 1.240 GHz - 1.300 GHz | |||
13 cm | 2.300 GHz - 2.450 GHz | |||
SHF | 9 cm | 3.400 GHz - 3.475 GHz3 | 3.300 GHz - 3.500 GHz | 3.300 GHz - 3.500 GHz |
5 cm | 5.650 GHz - 5.850 GHz | 5.650 GHz - 5.925 GHz | 5.650 GHz - 5.850 GHz | |
3 cm | 10.000 GHz - 10.500 GHz | |||
1.2 cm | 24.000 GHz - 24.250 GHz | |||
EHF | 6 mm | 47.000 GHz - 47.200 GHz | ||
4 mm3 | 75.500 GHz1 - 81.500 GHz | 76.000 GHz - 81.500 GHz | 76.000 GHz - 81.500 GHz | |
2.5 mm | 122.250 GHz - 123.000 GHz | |||
2 mm | 134.000 GHz - 141.000 GHz | |||
1 mm | 241.000 GHz - 250.000 GHz | |||
THF | Sub-mm | Some administrations have authorized spectrum for amateur use in this region. | ||
1 This is not mentioned in the ITU's Table of Frequency Allocations, but it is a de facto international amateur radio allocation. |
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See also: Radio spectrum · Electromagnetic spectrum |