Amateur radio frequency allocations explained

Amateur radio frequency allocation is done by national telecommunication 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.[1] The list of frequency ranges is called a band allocation, which may be set by international agreements, and national regulations. The modes and types of allocations within each frequency band is called a bandplan; it may be determined by regulation, but most typically is set by agreements between amateur radio operators.

National 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.[2] [3]

Band characteristics

Low frequency

See also: Low frequency.

Just below the Asian and European longwave broadcast band and far below the commercial AM broadcast band.

Medium frequency

See also: Medium frequency.

Just below the commercial AM broadcast band and the maritime radio band.

Just above the commercial AM broadcast band. Allocations in this band vary widely from country to country; it was formerly shared with the largely defunct Loran-A radionavigation system.

This band is often taken up as a technical challenge, since long distance (DX) propagation tends to be more difficult due to higher D layer ionospheric absorption. Long-distance propagation tends to occur only at night, and the band can be notoriously noisy particularly in the summer months.

160 metres is also known as the "top band". For many years it was the longest-wavelength amateur band; although often included among the shortwaves, it is actually located near the top end of the medium frequency band.

High frequency

See also: High frequency.

Most of the customary band names given below are only nominal wavelengths, not actual wavelengths. For example:

Best at night, with significant daytime signal absorption. Works best in winter, due to atmospheric noise from hemispheric thunder storms during summer. 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) (85.65–83.28 m).

In the US and Canada the portion of the band from 3.600–4.000 MHz, regulation permits use of single-sideband voice as well as AM voice; this sub-band is often referred to as "the 75 metre band", in part to distinguish it from the internationally available frequencies below it.

A relatively new allocation and originally only available in a small number of countries such as the United States, United Kingdom, Ireland, Norway, Denmark, and Iceland, but now continuing to expand. In most (but not all) countries, the allocation is broken into channels and may require a special licensing request.

Five 2.8 kHz-wide channels are available in the U.S., centered on 5.332, 5.348, 5.368, 5.373, and 5.405 MHz. Since most radios in SSB mode display the (suppressed) carrier frequency, in USB mode the dial frequencies would all need to be set 1.5 kHz lower. Voice operation is generally in upper sideband mode, which is mandatory in the U.S. . The U.S. and Canada allow 100 Watts in the currently available channels.

The 2015 ITU World Radiocommunication Conference (WRC-15) approved a new worldwide frequency allocation of 5.351.5–5.366.5 MHz to the amateurs on a secondary basis. The allocation limits amateur stations to 15 watts effective isotropic radiated power (EIRP); however some locations will be permit up to 25 W EIRP.

Considered the most reliable all-season long distance (DX) band. Popular for DX at night, 40 metres is also reliable for medium distance (1,500 km / 1,000 miles) contacts during the day. Much of this band was shared with broadcasters, and in most countries the bottom 100 kHz or 200 kHz are available to amateurs. However, due to the high cost of running high-power commercial broadcasting facilities, decreased listenership, and increasing competition from Internet-based international broadcast services, many shortwave broadcasting services are being shut down, leaving the 40 metre band free of other users for amateur radio use.

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.

For example, in the US, data, RTTY, and CW are the only modes allowed at a maximum 200 W peak envelope power (PEP) output. Not released for amateur use in a small number of countries.

Due to its location in the centre of the shortwave spectrum, this band provides significant opportunities for long-distance communication at all points of the solar cycle. 30 metres is a WARC band. "WARC" bands are so called due to the 1979 special World Administrative Radio Conference allocation of these newer bands to amateur radio use. Amateur radio contests are not run on the WARC bands.

Considered the most popular DX band; usually most popular during daytime. QRP operators recognize 14.060 MHz as their primary calling frequency within the band. Users of the PSK31 data mode tend to congregate around 14.070 MHz. Analog SSTV activity centers on 14.230 MHz.

Similar to 20 metres, but more sensitive to solar propagation minima and maxima. 17 metres is a WARC band.

Most useful during solar maximum, and generally a daytime band. Daytime sporadic E propagation (1,500 km / 1,000 miles) occasionally occurs on this band.

Mostly useful during daytime, but opens up for DX activity at night, during solar maximum. 12 metres is one of the WARC bands. Propagates via sporadic E and by F2 propagation.

Best long distance (e.g., across oceans) 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 propagation, day or night.

Due to Sporadic E propagation during the late spring and most of the summer, regardless of sunspot numbers, afternoon short band openings into small geographic areas of up to 1,500 km (1,000 miles) occur. Sporadic E is caused by areas of intense ionization in the E layer of the ionosphere. The causes of sporadic E are not fully understood, but these "clouds" of ionization can provide short-term propagation from 17 metres all the way up to occasional 2 metre openings. FM operations are normally found at the high end of the band (Also repeaters are in the 29.500–29.700 MHz segment in many countries).

Very-high frequencies and ultra-high frequencies

Frequencies above 30 MHz are referred to as Very High Frequency (VHF) region and those above 300 MHz are called Ultra High Frequency (UHF). The allocated bands for amateurs are many megahertz wide, allowing for high-fidelity audio transmission modes (FM) and very fast data transmission modes that are unfeasible for the kilohertz-wide allocations in the HF bands.

VHF
8 metres40–45 MHzin parts of ITU Region 1
50–54 MHz
 50–52 MHzIn parts of ITU Region 1
70–70.5 MHz in parts of ITU Region 1
144–148 MHz
 144–146 MHzITU Region 1
  219–220 MHz   Fixed digital message forwarding systems
  222–225 MHz US & Canada
UHF
420–450 MHz
 430–440 MHzin ITU Region 1
902–928 MHz in ITU Region 2
1 240–1 300 MHz
  1 240–1 325 MHz in UK
2 300–2 310 MHz   lower segment
  2 390–2 450 MHz   upper segment

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 signal transmitted on VHF from a hand-held portable will typically travel about 5–10 km (3–6 miles) depending on terrain. With a low power home station and a simple antenna, range would be around 50 km (30 miles).

With a large antenna system like a long yagi, and higher power (typically 100 watts or more) contacts of around 1 000 km (600 miles) using the Morse code (CW) and single-sideband (SSB) modes are common. Ham operators seek to exploit the limits of the frequencies usual characteristics looking to learn, understand, and experiment with the possibilities of these enhanced propagation modes.

Sporadic band openings

Occasionally, several different ionospheric conditions allow signals to travel beyond the ordinary line-of-sight limits. Some amateurs on VHF seek to take advantage of "band openings" where natural occurrences in the atmosphere and ionosphere extend radio transmission distances well over their normal range. Many hams listen for hours hoping to take advantage of these occasional extended propagation "openings".

The ionospheric conditions are called sporadic E and anomalous enhancement. Less frequently used anomalous modes are tropospheric scatter and Aurora Borealis (Northern Lights). Moon bounce and satellite relay are also possible.

Sporadic E

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[er] band" VHF radio frequencies.

The 6 metre amateur band falls into this category, often called "the magic band", will often "open up" from one small area into another small geographic area away during the spring and early summer months. This phenomenon occurs during the fall months, although not as often.

Tropospheric refraction

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 or foggy days, but it also causes VHF and 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 kilometres (miles) due to these unique weather conditions.

For example: The longest distance reported contact due to tropospheric refraction on 2 metres is 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 [4]

Tropo-scatter happens when water droplets and dust particles refract a VHF or UHF signal over the horizon. Using relatively high power and a high gain antenna, this propagation will give marginal enhanced over-the-horizon VHF and UHF communications up to several hundred kilometres (miles). During the 1970s commercial "scatter site" operators using huge parabolic antennas and high power used this mode successfully for telephone communications services into northern remote Alaska and Canadian communities.

Satellite, buried fibre optic, and terrestrial microwave access have relegated commercial use of 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.

Anomalous trans-equatorial enhancement

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 or 4 metres, and very rarely on 2 metres (high band VHF) during extreme peaks in the 11 year sunspot cycle.

The longest terrestrial contact ever reported on 2 metres (146 MHz) was between a station in Italy and a station in South Africa, a distance of 7 784 km (4 837 miles), using trans-equatorial 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 2 500–3 000 km (1500–1900 miles) within either side of the equator.[5]

Auroral backscatter

An intense solar storm causing aurora borealis (northern lights) will also provide occasional propagation enhancement to HF-low (6-metre) band radio waves. Aurorae only occasionally affect signals on the 2 metre band. 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 if the signal originates from a station to the east or west of the receiver. This effect is most significant in the latitudes north of 45 degrees.

Moon bounce (Earth-Moon-Earth)

Amateurs do successfully communicate by bouncing their signals off the surface of the Moon, called Earth-Moon-Earth (EME) transmission.

The mode requires moderately high power (more than 500 watts) and a fairly large, high-gain antenna because round-trip path loss is on the order of 270 dB for 70 cm signals. Return signals are weak and distorted because of the relative velocities of the transmitting station, Moon and the receiving station. The Moon's surface is also very rocky and irregular.

Because of the weak, distorted return signals, Moon bounce communications use digital modes. For example, old-fashioned Morse code or modern JT65, designed for working with weak signals.

Satellite relay

Satellite relay is not really a propagation mode, but rather an active repeater system. Satellites have been highly successful in providing VHF/UHF/SHF users "propagation" beyond the horizon.

Amateurs have sponsored the launch of dozens of communications satellites since the 1970s. These satellites are usually known as OSCARs (Orbiting Satellite Carrying Amateur Radio). Also, the ISS has amateur radio repeaters and radio location services on board.

Amateur television

See main article: Amateur television. 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.

Below the MW broadcast band

See also: 500 kHz, 630 meter band and {{nobr. 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 parts of the 500 kHz band are no longer used for regular maritime communications, some countries permit amateur radio radiotelegraph operations in that band. Many countries, however, continue to restrict these frequencies which were historically reserved for maritime and aviation distress calls.[6] The band is available for use in several countries, and the 2007 World Radiocommunication Conference (WRC-07) recommended it as a worldwide amateur allocation. Before the introduction of the band in the U.K. in 1998, operation on the even lower frequency of 73 kHz, in the LF time signal band, was allowed from 1996–2003.

ITU Region 1

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).

Table of amateur MF and HF bandplans

The following charts show the voluntary bandplans used by amateurs in ITU Region 1. Unlike the US, slots for the various transmission modes are not set by the amateur's license but most users do follow these guidelines.

160 metres

See also: 160-metre.

width=120px 160 metreswidth= 10px width= 28px 1810 – 1838width= 2px 1838 – 1840width= 3px 1840 – 1843width=157px 1843 – 2000
IARU Region 1

80 metres

See also: 80-metre band.

width=120px 80 metreswidth= 80px 3500 – 3570width= 30px 3570 – 3600width= 20px 3600 – 3620width=180px 3620 – 3800
IARU Region 1

60 metres

See also: 60-metre band.

width=120px 60 metreswidth= 25px 5258.5 – 5264width= 3px width= 25px 5276 – 5284width= 4px width= 25px 5288 – 5292width= 6px width= 25px 5298 – 5307width= 5px width= 25px 5313 – 5323width= 7px width= 25px 5333 – 5338width= 7px width= 70px 5351.5 – 5366.5, UK 5354 – 5358width= 4px width= 30px 5362 – 5374.5width= 3px width= 25px 5378 – 5382width= 7px width= 30px 5395 – 5401.5width= 2px width= 30px 5403.5 – 5406.5
IARU R1 (WRC-15) & UKWRC-15 alloc.
Also additional channels allocated to WRC-15 Band (or channel) for Bahrain*, North Macedonia,[7] Portugal, Republic of Ireland and Israel.
width=120px 60 metreswidth=250px 5250 – 5450
Bulgaria, Denmark
5370 – 5450 Estonia, 5260 – 5410 Norway, 5275 – 5450 Kenya, 5060 – 5450 Somalia.

40 metres

width=120px 40 metreswidth= 40px 7000 – 7040width= 10px 7040 – 7050width= 10px 7050 – 7060width= 40px 7060 – 7100width=100px 7100 – 7200
IARU Region 1
Note: 7000 – 7300 Somalia

30 metres

width=120px 30 metreswidth= 30px 10100 – 10130width= 20px 10130 – 10150
IARU Region 1

20 metres

width=120px 20 metreswidth= 70px 14000 – 14070width= 29px 14070 – 14099width= 2px Bwidth=249px 14101 – 14350
IARU Region 1

17 metres

width=120px 17 metreswidth= 27px 18068 – 18095width= 14px 18095 – 18109width= 2px Bwidth= 58px 18111 – 18168
IARU Region 1

15 metres

width=120px 15 metreswidth= 70px 21000 – 21070width= 40px 21070 – 21110width= 10px 21110 – 21120width= 29px 21120 – 21149width= 2px Bwidth=300px 21151 – 21450
IARU Region 1

12 metres

width=120px 12 metreswidth= 35px 24890 – 24915width= 14px 24915 – 24929width= 2px Bwidth= 49px 24931 – 24990
IARU Region 1

10 metres

width=120px 10 metreswidth= 70px 28000 – 28070width=120px 28070 – 28190width= 35px Bwidth=415px 28225 – 29200width= 50px 29200 – 29300width=105px 29300 – 29510width=145px 29510 – 29700
IARU Region 1

Key

ITU Region 2

ITU Region 2 consists of the Americas, including Greenland.

The frequency allocations for hams in ITU Region 2 are:

ITU bandBand nameFrequencies (kHz/MHz/GHz)
Lower endUpper end
5, LF (kHz)135.7 kHz 137.8 kHz
Power restricted, but no license required in
unallocated 160 - 190 kHz broadcast band.
6, MF (kHz)472 kHz 479 kHz
1800 2000
7, HF (MHz)3.5 MHz 4.0 MHz
Channelized: 5.332, 5.348, 5.358.5, 5.373, 5.405
or 5.351.5 - 5.366.5 or 5.250 - 5.450
7.0 7.3
10.1 10.15
14.00 14.35
18.068 18.168
21 21.45
24.89 24.99
28.0 29.7
8, VHF (MHz)50 MHz 54 MHz
144 148
219 220
222 225
9, UHF420 MHz 450 MHz
902 928
1240 1300
13 centimetres2300 2310
2390 2450
10, SHF (GHz)3.3 GHz 3.5 GHz
5.650 5.925
10.0 10.5
24.00 24.25
11, EHF47.0 47.2
75.5 81.0
122.5 123.0
134 141
241 250

Special note on the channelled 60 metre band

(ARRL 60 meter operations http://www.arrl.org/files/file/Regulatory/Recommended_Practices_Version_6_5.pdf)

The primary (first priority) user of the channelled 60 meter band is the U.S. National Telecommunications and Information Administration (NTIA). Effective 5 March 2012 the FCC permits CW, USB, and certain digital modes on these frequencies by amateurs on a secondary basis.

The FCC Report and Order permits the use of digital modes that comply with emission designator “60H0J2B”, which includes PSK31 as well as any RTTY signal with a bandwidth of less than 60 Hz. The Report and Order also allows the use of modes that comply with emission designator “2K80J2D”, which includes any digital mode with a bandwidth of 2.8 kHz or less whose technical characteristics have been documented publicly, per Part 97.309(4) of the FCC Rules. Such modes would include PACTOR I, II, or III, 300 baud packet, MFSK, MT63, Contestia, Olivia, DominoEX, and others.

On 60 meters, hams are restricted to only one signal per channel, and automatic operation is not permitted. In addition, the FCC continues to require that all digital transmissions be centred on the channel-centre frequencies, which the Report and Order defines as being 1.5 kHz above the suppressed carrier frequency of a transceiver operated in the upper side-band (USB) mode. As amateur radio equipment displays the carrier frequency, it is important for operators to understand correct frequency calculations for digital "sound-card" modes to ensure compliance with the channel-center requirement.

The ARRL has a Web site: detailed band plan . none. for US hams showing allocations within each band.

RAC has a Web site: chart showing the frequencies available to amateurs in Canada . none. .

Table of amateur MF and HF allocations in the United States and Canada

width=120px 160 mwidth=210px 1800 – 2000
1800 – 2000
General, Advanced, Extra
width=120px 80 / 75 m3500 – 4000
width= 25px 3500 – 3525width= 75px 3525 – 3600width=100px 3600 – 3700width=100px 3700 – 3800width=200px 3800 – 4000
Novice / Technician
General
Advanced
Extra
width=120px 60 m5330 – 5406
width= 20px 5332.0width= 20px width= 20px 5348.0width= 20px width= 20px 5358.5width= 20px width= 20px 5373.0width= 20px width= 20px 5405.0width= 20px
width= 20px 5332.0 width= 13px width= 20px 5348.0width= 17px width= 20px 5358.5width= 13px width= 20px 5373.0width= 29px width= 20px 5405.0width= 20px
General, Advanced, Extra
Basic (hon.), Code, Adv.
Note: US licensees operating 60 m are limited to 100 watts PEP ERP relative to a 1/2 wave dipole. Canadian operators are restricted to 100 watts PEP.[8]
width=120px 40 m7000 – 7300
width= 25px 7000 – 7025width=100px 7025 – 7125width= 50px 7125 – 7175width=125px 7175 – 7300
Novice / Technician
General
Advanced
Extra
width=120px 30 mwidth= 50px 10100-10150
Note: US limited to General, Advanced and Extra licensees; 200 watts PEP
width=120px 20 m14000 – 14350
width= 25px 14000-14025width=125px 14025-14150width= 25px 14150-14175width= 50px 14175-14225width=125px 14225-14350
General
Advanced
Extra
width=120px 17 m18068 – 18168
width= 42px 18068 – 18110width= 58px 18110 – 18168
General, Advanced, Extra
width=120px 15 m21000 – 21450
width= 25px 21000 – 21025width=175px 21025 – 21200width= 25px 21200 – 21225width= 50px 21225 – 21275width=175px 21275 – 21450
Novice / Technician
General
Advanced
Extra
width=120px 12 m24890 – 24990
width= 50px 24890 – 24930width= 50px 24930 – 24990
General, Advanced, Extra
width=120px 10 m28000 – 29700
width=100px 28000 – 28300width=67px 28300 – 28500width=400px 28500 – 29700
Novice / Technician
General, Advanced, Extra
Note: The 10 metre table is one-third scale, relative to the other tables

Key

ITU Region 3

ITU region 3 consists of Australia, Indonesia, Japan, New Zealand, the South Pacific, and Asia south of Siberia. The IARU frequency allocations for hams in ITU Region 3[9] are:

ITU bandBand nameFrequencies (MHz)
Lower end Upper end
5, LF135.7 kHz 137.8 kHz
6, MF472 kHz 479 kHz
1.8 2.0
7, HF3.5 3.9
5.351.5 5.366.5
7.0 7.3
10.1 10.15
14 14.35
18.068 18.168
21 21.45
24.89 24.99
28 29.7
8, VHF50 54
144 148
9, UHF430 450
1240 1300

Bands above 1300 MHz: societies should consult with the amateur satellite community for proposed satellite operating frequencies before deciding local bandplans above 1300 MHz.

Not all Member Unions follow this plan. As an example, the ACMA does not allow Australian Amateurs to use 3.700 MHz to 3.768 MHz and 3.800 MHz to 3.900 MHz, allocating this region to Emergency and Ambulatory services (Allocations can be found conducting a search of the ACMA Radcomms register http://web.acma.gov.au/pls/radcom/register_search.main_page.)

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 for New Zealand.

The Japanese have charts for Amateur frequencies in Japan[10]

Space operations

See also: amateur radio satellite. 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 50km (30miles) 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
RangeBandLetterAllocationPreferred sub-bandsUser statusNotes
HF40 mPrimary
20 mPrimary
17 mPrimaryEntire amateur radio band
15 mHPrimaryEntire amateur radio band
12 mPrimaryEntire amateur radio band
10 mAPrimaryEntire amateur radio band
VHF2 mVPrimary
UHF70 cmU
23 cmLOnly uplinks allowed
13 cmS
SHF9 cmS2Not available in ITU region 1.
5 cmCOnly uplinks allowed
SecondaryOnly downlinks allowed
3 cmXSecondary
1.2 cmKPrimary
EHF6 mmRPrimaryEntire amateur radio band
4 mmSecondary
Primary
Secondary
2 mmPrimaryEntire amateur radio band
Secondary
1 mmSecondaryEntire amateur radio band
Primary

See also

Notes and References

  1. Web site: HF Band Table . life.itu.int . 10 November 2018.
  2. Web site: Frequency Bands . ARRL . 27 June 2011. https://web.archive.org/web/20110604234239/http://www.arrl.org/frequency-bands. 4 June 2011 . live.
  3. Larry D. Wolfgang et al., (ed), The ARRL Handbook for Radio Amateurs, Sixty-Eighth Edition, (1991), ARRL, Newington CT USA Chapter 37
  4. Web site: Hadley cell propagation . DF5AI.net .
  5. Web site: DX records . sektion-vhf.ssa.se . 17 August 2008 . dead . https://web.archive.org/web/20081016011710/http://sektion-vhf.ssa.se/dxrecord/dxrec.htm . 16 October 2008 . dmy-all .
  6. Web site: Maritime Radio Historical Society . dead . 8 April 2016 . 31 March 2016 . https://web.archive.org/web/20160331181540/http://radiomarine.org/gallery/show?keyword=USNAVY&panel=pab1_7 .
  7. http://z37rsm.org.mk/index.php/90-2010-03-21-23-40-11/348-5mhz Odobreno koristenie na 5 Mhz
  8. Web site: Policy and Technical Framework for Amateur Service Use in the 5 MHZ Band. 21 January 2014.
  9. Region 3 Band allocations Web site: Band Plans IARU Region 3 . International Amateur Radio Union - Region 3 . 15 October 2015 . 12 January 2017 . https://web.archive.org/web/20171216012537/http://www.iaru-r3.org/wp-content/files/R3-004%20Band%20Plans%20IARU%20Region%203.docx . 16 December 2017 . dead .
  10. Amateur frequencies for Japan Web site: Japanese Bandplans . The Japan Amateur Radio League, Inc. (JARL) . 21 April 2020 . 30 June 2022.