Amateur radio station with transceivers, amplifiers, and a computer for digital modes. On the wall are awards, certificates, andQSL cards from foreign stations
Amateur radio, also known asham radio, is the use of theradio spectrum for non-commercial communication, technical experimentation, self-training, recreation,radiosport,contesting, andemergency communications.[1] In 1927 aradio amateur was defined as "a duly authorized person interested in radioelectric practice with a purely personal aim and withoutpecuniary interest," meaning without monetary or similar reward. The definition distinguished amateur activity fromcommercial broadcasting, public safety services, and professionaltwo-way radio uses such as maritime, aviation, and taxi communication.[2]
Polish amateur radio station SP1QE with a 1930svacuum tube transmitter and receiver
Operators are authorised to transmit on frequency ranges allocated internationally as theamateur radio bands. Within these bands they may use anyfrequency, though some are restricted to particular modes of voice, text, image, ordata communications. This allows communication locally, nationally, worldwide, and even with stations in space. In many countries, operators may also exchange radio communications betweencomputers ortransceivers connected throughvirtual private networks on theInternet.
Amateur radio is represented by theInternational Amateur Radio Union (IARU), which has three regions and includes national amateur radio societies in most countries. In 2011 theAmerican Radio Relay League (the U.S. national society) estimated that about 2 million people worldwide were active in amateur radio.[3] About 830,000amateur radio stations are inRegion 2 (the Americas), about 750,000 inRegion 3 (South and East Asia and the Pacific), and about 400,000 inRegion 1 (Europe, the Middle East, theCIS and Africa).
An amateur radio station inWales. Multiple transceivers are employed for different bands and modes. Computers are used for control, data modes, SDR, RTTY and logging.
The origins of amateur radio can be traced to the late 19th century, but amateur radio as practised today began in the early 20th century. TheFirst Annual Official Wireless Blue Book of the Wireless Association of America, produced in 1909, contains a list of amateur radio stations.[4] This radiocallbook listswireless telegraph stations in Canada and the United States, including 89 amateur radio stations. As with radio in general, amateur radio was associated with various amateur experimenters and hobbyists. Amateur radio enthusiasts have significantly contributed toscience,engineering, industry, andsocial services. Research by amateur operators has founded new industries, like experimentation with quartzpiezoelectric resonators from 1924 until about 1934[5] built economies,[6] empowered nations,[7] and saved lives in times of emergency.[8][9] Ham radio can also be used in the classroom to teach English, map skills, geography, math, science, and computer skills.[10]
The term"ham" was first apejorative term used in professionalwired telegraphy during the 19th century, to mock operators with poorMorse code-sending skills ("ham-fisted").[11][12][13][14] This term continued to be used after the invention of radio, and the proliferation of amateur experimentation with wireless telegraphy; among land- and sea-based professional radio telegraphers,"ham" amateurs were considered a nuisance. The use of"ham" meaning"amateurish or unskilled" survives today sparsely in other disciplines (e.g."ham actor").
The amateur radio community subsequently reclaimed the word as a label of pride,[15] and by the mid-20th century it had lost its pejorative meaning. Although not an acronym or initialism, it is occasionally written as "HAM" in capital letters.
Amateur radio combines communication, technical experimentation, and recreation. Operators take part in contests, provide emergency service, build and modify equipment, and use transmission modes ranging from traditional Morse code to modern digital protocols.
Operators often join conversational groups and take part in scheduled on-air meetings callednets, coordinated by a net control station.[16] Nets may provide training for emergencies, operate as informal discussions, or focus on specialised topics.[17]
With battery- or generator-powered equipment, operators frequently provide communication during natural disasters when commercial services are unavailable.[18]
Radiotelegraphy usingInternational Morse code, or continuous wave (CW), is one of the oldest modes in amateur radio. Although largely replaced in professional services, it remains in use onshortwave bands because it functions under weak-signal conditions and employs internationally understood codes such as theQ code. CW is also used by hobbyists who build their own equipment (home construction) and by operators engaged inlow-power operation, as CW transmitters are simple to construct and weak signals can often be received by ear.
Until 2003, Morse code proficiency was required under international regulations for access to frequencies below 30 MHz.[21] The requirement was withdrawn in the United States in 2007.[22][23]
Personal computers have enabled new digital transmission modes.Radioteletype (RTTY), once operated by mechanical devices,[24] is now handled in software. Packet radio, developed in the 1970s, uses protocols such asAX.25 andTCP/IP. Later modes includingPSK31 andFT8 allow efficient low-signal communication on shortwave bands.
Other specialised modes support weak-signal communication. Automatic link establishment (ALE) maintains networks onhigh frequency bands, while theWSJT suite supportsmeteor scatter andmoonbounce.[26]
Fast-scanamateur television (ATV) adapts consumer video equipment to transmit images. It typically operates on the70 cm (420–450 MHz) but may also use the33 cm and higher frequencies. Because of wide bandwidth requirements, ATV usually covers 30–100 km (20–60 mi). Linkedrepeater systems extend this range to several hundred kilometres.[27] Repeaters are often located on high ground or towers and may be linked by other amateur bands, landlines, or the Internet.
Most countries require candidates to pass an examination that tests electronics, radio propagation, operating practices, and regulations.[34] Licensing grants access to a broader portion of the spectrum, additional communication modes, and higher transmitter power than unlicensed personal radio services such asCB,FRS, orPMR446.[35]
The top of a tower supporting aYagi–Uda antenna and several wire antennas, along with a Canadian flag
Examination systems often include several levels, each granting wider frequency access and higher power limits.[36][37] In the United Kingdom and Australia, entry-level candidates must also complete a practical skills test to obtain the Foundation Licence, the first of three licensing stages.[38]
Each licensee is normally assigned a uniquecall sign.[39] Some countries issue additional station licences, or recognise club and organisational licences.[40]
Licences are generally valid only in the issuing country or in states with reciprocal agreements.[41][42] In some jurisdictions, a licence is also required to purchase or possess amateur radio equipment.[43]
In the United States, theFederal Communications Commission (FCC) issues three licence classes: Technician, General, and Amateur Extra.[44] Examinations are administered by accredited Volunteer Examiners through the FCC's Volunteer Examiner Coordinator system. Higher licence classes provide access to more frequency bands and higher transmitter power. The tests cover regulations, operating practices, electronics theory, equipment design, and safety. Morse code is no longer tested. Licences are valid for ten years, and the national question pools are published in advance and updated every four years.[44]
Prospective amateur radio operators are examined on understanding of the key concepts of electronics, radio equipment, antennas,radio propagation,RF safety, and the radio regulations of the government granting the license.[1] These examinations are sets of questions typically posed in either a short answer or multiple-choice format. Examinations can be administered bybureaucrats, non-paid certified examiners, or previously licensed amateur radio operators.[1]
The ease with which an individual can acquire an amateur radio license varies from country to country. In some countries, examinations may be offered only once or twice a year in the national capital and can be inordinately bureaucratic (for example in India) or challenging because some amateurs must undergo difficult security approval (as inIran). Currently, onlyYemen andNorth Korea do not issue amateur radio licenses to their citizens.[45][46] Some developing countries, especially those in Africa, Asia, andLatin America, require the payment of annual license fees that can be prohibitively expensive for most of their citizens. A few small countries may not have a national licensing process and may instead require prospective amateur radio operators to take the licensing examinations of a foreign country. In countries with the largest numbers of amateur radio licensees, such as Japan, the United States, Thailand, Canada, and most of the countries in Europe, there are frequent license examinations opportunities in major cities.
Granting a separate license to a club or organization generally requires that an individual with a current and valid amateur radio license who is in good standing with the telecommunications authority assumes responsibility for any operations conducted under the club license or club call sign.[47] A few countries may issue special licenses to novices or beginners that do not assign the individual a call sign but instead require the newly licensed individual to operate from stations licensed to a club or organization for a period of time before a higher class of license can be acquired.[1]
Map of amateur radio reciprocal licensing agreements. CEPT members IARP members CEPT and IARP USA–Canada treaty, CEPT, and IARP
A reciprocal licensing agreement between two countries allows licensed amateur radio operators from one country to operate stations in the other without obtaining a new licence. In some cases, visiting operators may be issued a temporary local licence and call sign.
Requirements vary by jurisdiction. Some countries have bilateral or multilateral agreements that harmonise conditions, while others have no reciprocal arrangements. Regional organisations, such as theOrganization of American States, facilitate reciprocity through treaties, including the Inter-American Amateur Radio Service Convention.[48]
An amateur radio operator uses acall sign on the air to legally identify the operator or station.[52] In some countries, the call sign assigned to the station must always be used, whereas in other countries, the call sign of either the operator or the station may be used.[53] In certain jurisdictions, an operator may also select a"vanity" call sign although these must also conform to the issuing government's allocation and structure used for amateur radio call signs.[54] Some jurisdictions require a fee to obtain a vanity call sign; in others, such as the UK, a fee is not required and the vanity call sign may be selected when the license is applied for. The FCC in the U.S. discontinued its fee for vanity call sign applications in September 2015, but reinstated it at $35 in 2022.[55]
Call sign structure as prescribed by the ITU consists of three parts which break down as follows, using the call signZS1NAT as an example:
ZS
The first part may be one or two letters (or a single digit followed by a single letter); it shows the country from which the call sign originates and may also indicate the license class. (This call sign is licensed in South Africa.)
1
The second part is always a single digit that appears as the second or third character, and always follows a letter; it normally gives the subdivision of the country or territory indicated in the first part (this one refers to the Western Cape).
NAT
The third part is a set of one, two, or three letters that immediately follows the digit in the second part (the digit in the second or third character); it uniquely identifies the holder of the license. (In the examples below, the third part is represented by "xxx".)
The combination of the three parts identifies the specific transmitting station, and the station's identification (its call sign) is determined by the license held by its operator. In the case of commercial stations and amateur club stations, the operator is a corporation; in the case of amateur radio operators, the license-holder is a resident of the country identified by the first part of the call sign.
Many countries do not follow the ITU convention for the second-part digit. In the United Kingdom the original callsG0xxx,G2xxx,G3xxx,G4xxx, were Full (A) License holders along with the lastM0xxx full call signs issued by theCity & Guilds examination authority in December 2003. Additional Full Licenses were originally granted to (B) Licenses withG1xxx,G6xxx,G7xxx,G8xxx and 1991 onward withM1xxx call signs. The newer three-level Intermediate License holders are assigned2E0xxx and2E1xxx, and the basic Foundation License holders are granted call signsM3xxx,M6xxx orM7xxx.[56]
Instead of using numbers, in the U.K. the second letter after the initial 'G' or 'M' identifies the station's location; for example, a call signG7OOE becomesGM7OOE andM0RDM becomesMM0RDM when the license holder is operating their station in Scotland. PrefixGM &MM are Scotland,GW &MW are Wales,GI &MI are Northern Ireland,GD &MD are the Isle of Man,GJ &MJ are Jersey andGU &MU are Guernsey. Intermediate licence call signs are slightly different. They begin2z0 and2z1 where thez is replaced with one of the country letters, as above. For example2M0 and2M1 are Scotland,2W0 and2W1 are Wales and so on. The exception however is for England, whose letter would be 'E'; however, letter 'E'is used, butonly in intermediate-level call signs, and perplexingly never by the advanced licenses. For example2E0 &2E1 are used whereas the call signs beginning 'G' or 'M' for foundation and full licenses never use the 'E'.[57]
In the United States, for non-vanity licenses, the numeral indicates the geographical district the holder resided in when the license was first issued. Prior to 1978, US hams were required to obtain a new call sign if they moved out of their geographic district.
In Canada, call signs start withVA,VE,VY,VO, andCY. Call signs starting with 'V' end with a number after to indicate the political region; whereas the prefixCY indicates geographic islands. PrefixesVA1 andVE1 are used forNova Scotia;VA2 &VE2 forQuebec;VA3 &VE3 forOntario;VA4 &VE4 forManitoba;VA5 &VE5 forSaskatchewan;VA6 &VE6 forAlberta;VA7 &VE7 forBritish Columbia;VE8 for theNorthwest Territories;VE9 forNew Brunswick;VY0 forNunavut;VY1 for theYukon;VY2 forPrince Edward Island;VO1 forNewfoundland; andVO2 forLabrador.CY is for amateurs operating fromSable Island (CY0) orSt. Paul Island (CY9). Special permission is required to access either of these: fromParks Canada for Sable andCoast Guard for St. Paul. The last two or three letters of the call signs are typically the operator's choice (upon completing the licensing test, the ham writes three most-preferred options). Two-letter call sign suffixes require a ham to have already been licensed for 5 years. Call signs in Canada can be requested with a fee.
Also, for smaller geopolitical entities, the digit at the second or third character might be part of the country identification. For example,VP2xxx is in the British West Indies, which is subdivided intoVP2Exx Anguilla,VP2Mxx Montserrat, andVP2Vxx British Virgin Islands.VP5xxx is in the Turks and Caicos Islands,VP6xxx is on Pitcairn Island,VP8xxx is in the Falklands, andVP9xxx is in Bermuda.
Onlinecallbooks or call sign databases can be browsed or searched to find out who holds a specific call sign.[58] An example of an online callbook isQRZ.com. Various partial lists of famous people who hold or held amateur radio call signs have been compiled and published.[59]
Many jurisdictions (but not in the U.K. nor Europe) may issue specialtyvehicle registration plates to licensed amateur radio operators.[60][61] The fees for application and renewal are usually less than the standard rate for specialty plates.[60][62]
In most administrations, unlike other RF spectrum users, radio amateurs may build or modify transmitting equipment for their own use within the amateur spectrum without the need to obtain government certification of the equipment.[63][a][64][b] Licensed amateurs can also use any frequency in their bands (rather than being allocated fixed frequencies or channels) and can operate medium-to-high-powered equipment on a wide range of frequencies[65] so long as they meet certain technical parameters including occupied bandwidth, power, and prevention ofspurious emission.
Radio amateurs have access to frequency allocations throughout the RF spectrum, usually allowing choice of an effective frequency for communications across a local, regional, or worldwide path. The shortwave bands, orHF, are suitable for worldwide communication, and theVHF andUHF bands normally provide local or regional communication, while themicrowave bands have enough space, orbandwidth, for amateur television transmissions and high-speedcomputer networks.
The international symbol for amateur radio, is included in the logos of manyIARU member societies. The diamond holds acircuit diagram featuring components common to every radio: an antenna,inductor andground.
In most countries, an amateur radio license grants permission to the license holder to own, modify, and operate equipment that is not certified by a governmental regulatory agency. This encourages amateur radio operators to experiment with home-constructed or modified equipment. The use of such equipment must still satisfy national and international standards onspurious emissions.
Amateur radio operators are encouraged both by regulations and tradition of respectful use of the spectrum to use as little power as possible to accomplish the communication.[66] This is to minimise interference orelectromagnetic compatibility (EMC) to any other device. Although allowablepower levels are moderate by commercial standards, they are sufficient to enable global communication. Lower license classes usually have lower power limits; for example, the lowest license class in the UK (Foundation licence) has a limit of 25 W.[67]
Power limits vary from country to country and between license classes within a country. For example, thepeak envelope power limits for the highest available license classes in a few selected countries are: 2.25 kW in Canada;[68] 1.5 kW in the United States; 1.0 kW in Belgium,Luxembourg, Switzerland, South Africa, the United Kingdom, and New Zealand; 750 W in Germany; 500 W in Italy; 400 W in Australia and India; and 150 W inOman.
Output power limits may also depend on the mode of transmission. In Australia, for example, 400 W may be used forSSB transmissions, but FM and other modes are limited to 120 W.
The point at which power output is measured may also affect transmissions: The United Kingdom measures at the point the antenna is connected to the signal feed cable, which means the radio system may transmit more than 400 W to overcome signal loss in the cable; conversely, the U.S. and Germany measure power at the output of the final amplification stage, which results in a loss in radiated power with longer cable feeds.[citation needed]
Certain countries permit amateur radio licence holders to hold a Notice of Variation that allows higher power to be used than normally allowed for certain specific purposes. E.g. in the UK some amateur radio licence holders are allowed to transmit using (33 dBw) 2.0 kW for experiments entailing using the moon as a passive radio reflector (known asEarth–Moon–Earth communication) (EME).
TheInternational Telecommunication Union (ITU) governs the allocation of communications frequencies worldwide, with participation by each nation's communications regulation authority. National communications regulators have some liberty to restrict access to thesebandplan frequencies or to award additional allocations as long as radio services in other countries do not suffer interference. In some countries, specificemission types are restricted to certain parts of the radio spectrum, and in most other countries,International Amateur Radio Union (IARU) member societies adopt voluntary plans to ensure the most effective use of spectrum.
In a few cases, a national telecommunication agency may also allow hams to use frequencies outside of the internationally allocated amateur radio bands. InTrinidad and Tobago, hams are allowed to use a repeater which is located on 148.800 MHz. This repeater is used and maintained by theNational Emergency Management Agency (NEMA), but may be used by radio amateurs in times of emergency or during normal times to test their capability and conduct emergency drills. This repeater can also be used by non-ham NEMA staff andREACT members. In Australia and New Zealand, ham operators are authorized to use one of the UHF TV channels. In the U.S., amateur radio operators providing essential communication needs in connection with the immediate safety of human life and immediate protection of property when normal communication systems are not available may use any frequency including those of other radio services such as police and fire and in cases of disaster in Alaska may use the statewide emergency frequency of 5.1675 MHz with restrictions upon emissions.[69]
Similarly, amateurs in the United States may apply to be registered with theMilitary Auxiliary Radio System (MARS). Once approved and trained, these amateurs also operate on US government military frequencies to provide contingency communications and morale message traffic support to the military services.
Some administrations have authorized spectrum for amateur use in this region; others have declined to regulate frequencies above 300 GHz.
[t1]
All allocations are subject to variation by country. For simplicity, only common allocations found internationally are listed. See a band's article for specifics.
This is not mentioned in theITU'sTable of Frequency Allocations, but many individual administrations have commonly adopted this allocation under"Article 4.4".
[t4]
This includes a currently activefootnote allocation mentioned in the ITU'sTable of Frequency Allocations. These allocations may only apply to a group of countries.
Amateurs use a variety of voice, text, image, and data communication modes over radio. Generally new modes can be tested in the amateur radio service, although national regulations may require disclosure of a new mode to permit radio licensing authorities to monitor the transmissions.Encryption, for example, is not generally permitted in the Amateur Radio service except for the special purpose of satellite vehicle control uplinks.[citation needed] The following is a partial list of the modes of communication used, where the mode includes bothmodulation types and operating protocols.
In former times, most amateur digital modes were transmitted by inserting audio into the microphone input of a radio and using an analog scheme, such asamplitude modulation (AM),frequency modulation (FM), orsingle-sideband modulation (SSB). Beginning in 2017, increased use of several digital modes, particularlyFT8, became popular within the amateur radio community.[72]
^Hong Kong OFTA description of"radio amateur" privileges: Radio amateurs are free to choose any radio equipment designed for the amateur service. Radio amateurs may also design and build their own equipment provided that the requirements and limitations specified in theAmateur Station Licence and Schedules thereto are complied with.[63]
^FCC expectations of"radio amateurs": They design, construct, modify, and repair their[own] stations. The FCC equipment authorization program does not generally apply to amateur station transmitters.[64]
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