Amateur radio

Amateur radio From Wikipedia, the free encyclopedia Jump to: navigation, search Amateur radio station with modern solid-state transceiver featuring LCD and DSP capabilities Amateur radio, often called ham radio, is both a hobby and a service that uses various types of radio communications equipment to communicate with other radio amateurs for public service, recreation and self-training. A participant is called an amateur radio operator, or a ham.[1] Amateur radio operators enjoy personal wireless communications with each other and are able to support their communities with emergency and disaster communications if necessary, while increasing their personal knowledge of electronics and radio theory. An estimated six million people throughout the world are regularly involved with amateur radio.[2] The term "amateur" is not a reflection on the skills of the participants, which are often quite advanced; rather, "amateur" indicates that amateur radio communications are not allowed to be made for commercial or money-making purposes. Contents [hide] 1 History2 Activities and practices3 Licensing 3.1 Newcomers3.2 Callsigns3.3 Privileges3.4 Band plans and frequency allocations 4 Popular culture5 References6 See also7 External links // [edit] History Main article: Amateur radio history Though its origins can be traced to at least the late 1800s, amateur radio, as practiced today, began in the 1920s. As with radio in general, the birth of amateur radio was strongly associated with various amateur experimenters and hobbyists. Throughout its history, amateur radio enthusiasts have made significant contributions to science, engineering, industry, and social services. Research by amateur radio operators has founded new industries, built economies, empowered nations, and saved lives in times of emergency. The international symbol for amateur radio, included in the logos of many IARU member societies. The diamond holds a circuit diagram featuring components common to every radio: an antenna, inductor and ground. [edit] Activities and practices Radio amateurs use various modes of transmission to communicate. Voice transmissions are most common, with some such as frequency modulation (FM) offering high quality audio, and others such as single sideband (SSB) offering more reliable communications when signals are marginal and bandwidth is restricted. Radiotelegraphy using Morse code remains popular, particularly on the shortwave bands and for experimental work such as Moonbounce, with its inherent signal-to-noise ratio advantages. Morse, using internationally agreed code groups, also allows communications between amateurs who speak different languages. It is also popular with homebrewers as CW-only transmitters are simpler to construct. For many years, demonstrating a proficiency in Morse code was a requirement to obtain amateur licenses for the high frequency bands (frequencies below 30 MHz), but following changes in international regulations in 2003, countries are no longer required to demand proficiency.[3] As an example, the United States Federal Communications Commission phased out this requirement for all license classes on February 23, 2007.[4][5] Modern personal computers have led to a boom in digital modes such as radioteletype, which previously required cumbersome mechanical equipment.[6] Hams led the development of packet radio, which has even used protocols such as TCP/IP since the 1970s. This has since been augmented by more specialized modes such as PSK31 to allow real-time, low-power communications on the shortwave bands. Echolink using Voice over IP technology has enabled amateurs to communicate through local internet-connected repeaters and radio nodes, while IRLP has allowed easy linking together of repeaters. Other modes, such as FSK441 using software such as WSJT, are used for weak signal modes including meteor scatter and moonbounce communications. Similarly, fast scan amateur television, once considered esoteric, has exploded in popularity thanks to cheap camcorders and video cards in home computers. Because of the wide bandwidth and stable signals required, amateur television is typically found in the 70 cm (420—450 MHz) frequency range, though there is also limited use on 33 cm (902—928 MHz), 23 cm (1240—1300 MHz) and higher. These requirements also effectively limit the signal range to between 20 and 60 miles (30—100 km), however, the use of linked repeater systems can allow transmissions across hundreds of miles.[7] These repeaters, or automated relay stations, are used on VHF and higher frequencies to increase signal range. Repeaters are usually located on top of a mountain, hill or tall building, and allow operators to communicate over hundreds of square miles using a low power hand-held transceiver. Repeaters can also be linked together by use of other amateur radio bands, landline or the Internet. Communication satellites called OSCARs (Orbiting Satellite Carrying Amateur Radio) can be accessed, some using a handheld transceiver (HT) with a stock "rubber duck" antenna. Hams also use the moon and the ionized trails of meteors as reflectors of radio waves.[8] Hams are also often able to make contact with the International Space Station (ISS),[9] as many astronauts and cosmonauts are licensed as Amateur Radio Operators.[10] Amateur radio operators use their amateur radio station to make contacts with individual hams as well as participating in round table discussion groups or "rag chew sessions" on the air. Some join in regularly scheduled on-air meetings with other amateur radio operators, called "Nets" (as in "networks") which are moderated by a station referred to as "Net Control".[11] Nets can allow operators to learn procedures for emergencies, be an informal round table or be topical, covering specific interests shared by a group. [edit] Licensing Main article: Amateur radio license In all countries, amateur radio operators are required to pass a licensing exam displaying knowledge and understanding of key concepts. In response, hams are granted operating privileges in larger segments of the radio frequency spectrum using a wide variety of communication techniques with higher power levels permitted. This practice is in contrast to unlicensed personal radio services such as CB radio, Multi-Use Radio Service, or Family Radio Service / PMR446 that require type-approved equipment restricted in frequency range and power. A handheld VHF/UHF transceiver, 2007. In many countries, amateur licensing is a routine civil administrative matter. Amateurs are required to pass an examination to demonstrate technical knowledge, operating competence and awareness of legal and regulatory requirements in order to avoid interference with other amateurs and other radio services. There are often a series of exams available, each progressively more challenging and granting more privileges in terms of frequency availability, power output, permitted experimentation, and in some countries, distinctive callsigns. Some countries such as Great Britain and Australia have begun requiring a practical training course in addition to the written exams in order to obtain a beginner's license, called a Foundation License. Amateur radio licensing in the United States serves as an example of the way some countries award different levels of amateur radio licenses based on technical knowledge. Three sequential levels of licensing exams (Technician Class, General Class and Amateur Extra Class) are currently offered, which allow operators who pass them access to larger portions of the Amateur Radio spectrum and more desirable callsigns. Specialized Interests and modes While many hams simply enjoy talking to friends, others pursue a wide variety of specialized interests. Emergency communicationsHand building homebrew amateur radio gearDesigning new antennasCommunicating via amateur satellitesSevere weather spottingDX communication to far away countriesDX-peditionsUsing the Internet Radio Linking Project (IRLP) to connect radio repeaters via the InternetTracking vehicles using the Automatic Position Reporting System (APRS), which integrates with the GPSEngaging in the sport of contesting, earning awards, and collecting QSL cardsAmateur Radio Direction Finding, also known as "Fox hunting"High Speed TelegraphyLow-power operation (QRP).Vintage amateur radios, such as those using vacuum tube technologyHamfests, club meetings and swap meetsPortable, fixed, mobile and handheld operationVHF, UHF and microwave operation on amateur radio high bands [edit] Newcomers Many people start their involvement in amateur radio by finding a local club. Clubs often provide information about licensing, local operating practices and technical advice. Newcomers also often study independently by purchasing books or other materials, sometimes with the help of a mentor, teacher or friend. Established amateurs who help newcomers are often referred to as "Elmers" within the ham community. In addition, many countries have national amateur radio societies which encourage newcomers and work with government communications regulation authorities for the benefit of all radio amateurs. The oldest of these societies is the Wireless Institute of Australia, formed in 1910; other notable societies are the Radio Society of Great Britain, the American Radio Relay League, Radio Amateurs of Canada, the New Zealand Association of Radio Transmitters and South African Radio League. (See Category:Amateur radio organizations) [edit] Callsigns Upon licensing, a radio amateur's national government issues a unique callsign to the radio amateur. The holder of a callsign uses it on the air to legally identify the operator or station during any and all radio communication.[12] In certain jurisdictions, an operator may also select a "vanity" callsign.[13] Some jurisdictions, such as the U.S., require that a fee be paid to obtain such a vanity callsign; in others, such as the UK, a fee is not required and the vanity callsign may be selected when the license is applied for. Callsign structure as prescribed by the ITU, consists of three parts which break down as follows, using the callsign ZS1NAT as an example: ZS - Shows the country from which the callsign originates. This callsign is licensed in South Africa.1 - Tells you the subdivision of the country or territory indicated in the first part, this one refers to the Western Cape.NAT - The final part is specific to the holder of the licence, identifying that person specifically. [edit] Privileges Unlike all other spectrum users, radio amateurs are allowed to build or modify transmitting equipment, and do not need to obtain type-approval for it. 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[14] so long as they meet spurious emission standards. As noted, radio amateurs have access to frequency allocations throughout the RF spectrum, enabling choice of frequency to enable effective communication whether across a city, a region, a country, a continent or the whole world regardless of season or time day or night. The shortwave bands, or HF, can allow worldwide communication, the VHF and UHF bands offer excellent regional communication, and the broad microwave bands have enough space, or bandwidth, for television (known as SSTV and FSTV) transmissions and high-speed data networks. Although allowable power levels are moderate by commercial standards, they are sufficient to enable global communication. Power limits vary from country to country and between license classes within a country. For example, the power limits for the highest available license classes in a few selected countries are: 2.25 kilowatts in Canada, 2 kilowatts in most countries of the former Yugoslavia, 1.5 kilowatts in the United States, 1 kilowatt in Belgium and Switzerland, 750 watts in Germany, 500 watts in Italy, 400 watts in Australia, India and the United Kingdom, and 150 watts in Oman. Lower license classes usually have lower power limits; for example, the lowest license class in the UK has a limit of just 10 watts. When traveling abroad, visiting amateur operators must follow the rules of the country in which they wish to operate. Some countries have reciprocal international operating agreements allowing hams from other countries to operate within their borders with just their home country license. Other host countries require that the visiting ham apply for a formal permit, or even a new host country-issued license, in advance. [edit] Band plans and frequency allocations Main article: Amateur radio frequency allocations The International Telecommunication Union (ITU) governs the allocation of communications frequencies world-wide, with participation by each nation's communications regulation authority. National communications regulators have some liberty to restrict access to these frequencies or to award additional allocations as long as radio services in other countries do not suffer interference. In some countries, specific emission 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. In Trinidad and Tobago, hams are allowed to use a repeater which is located on 148.80 MHz. This repeater is used and maintained by the National 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 and REACT members. In Australia and New Zealand ham operators are authorized to use one of the UHF TV channels. In the U.S., in cases of emergency, amateur radio operators may use any frequency including those of other radio services such as police and fire communications and the Alaska statewide emergency frequency of 5165.7 kHz. Similarly, amateurs in the United States may apply to be registered with the Military Affiliate 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. [edit] Popular culture Amateur radio can be found throughout popular culture as a plot device. A classic example is the "Radio Ham" episode of 1960s British comedy series Hancock's Half Hour. Amateur radio has also been featured in several movies. Jurassic Park featured the use of a "CQ call" (which is used to initiate a conversation with a listening station). Contact, based on a novel by Carl Sagan, had its main character's childhood ham radio hobby evolve into a lifetime search for extraterrestrial radio signals. The movie Frequency featured amateur radio as a core part of the plot, though it mocked the hobby, claiming that it was antiquated and no longer practiced. There are and have been many famous Amateur radio operators, such as Nobel Prize laureate Joe Taylor, King Juan Carlos I of Spain, the late Prime Minister of India Rajiv Gandhi and his wife Sonia Gandhi, the late King Hussein of Jordan, Bollywood actor Amitabh Bachchan, U.S. radio and TV host Walter Cronkite, and Coast To Coast AM host Art Bell. Others include US General Curtis LeMay, former U.S. senator Barry Goldwater,[15] American guitarist Joe Walsh, U.S. actors and singers Lance Bass, Chet Atkins, Patty Loveless, Ronnie Milsap; Hollywood actor Marlon Brando, Bill "Bubba" Bussey from the nationally syndicated Rick and Bubba, computer hacker Kevin Mitnick, and cordless phone inventor George Sweigert. Wikimedia Commons has media related to: Amateur radio [edit] References Cited References ^ Lau, Mary E (2006-05-23). Ham Radio Frequently Asked Questions. ARRL.org. Retrieved on 2007-08-25.^ Silver, H Ward (2004-04-23). Amateur Radio for Dummies. Indianapolis: Wiley Publishing. ISBN 0764559877. OCLC 55092631. ^ FCC Report and Order 06-178A1 p. 7. Federal Communications Commission (2006-12-19). Retrieved on 2007-05-16.^ Federal Communications Commission (2007-01-24). "47 CFR Part 97". Federal Register 72 (15): pp. 3081-3082. Washington, D.C.: Government Printing Office. Retrieved on 2007-12-18.^ FCC to Drop Morse Testing for All Amateur License Classes. ARRL.org (2006-12-19). Retrieved on 2007-05-16.^ Galbraith, E Art. "KH6BB and "Mighty Mo," the Battleship Missouri", ARRL.org, 2003-08-23. Retrieved on 2007-01-10. ^ Taggart, Ralph E (April 1993). "An Introduction to Amateur Television". QST via ARRL.org: pp. 19—23. Retrieved on 2007-06-02.^ Taylor, Joe. "WSJT: New Software for VHF Meteor-Scatter Communication", QST via ARRL.org, pp. 36—41. Retrieved on 2007-01-11. ^ ARISS: Amateur Radio on the International Space Station. ARRL.org. Retrieved on 2007-01-10.^ Jurrens, Gerald. Astronaut (and Former Astronaut) Hams. gjurrens at Tellurian.com. Retrieved on 2007-01-10.^ Haag, Jerry. Principles of Amateur Radio Net Control. SCC-AREA-RACES.org. Retrieved on 2007-01-10.^ Amateur Radio (Intermediate) Licence (A) or (B) Terms, Provisions and Limitations Booklet BR68/I. Ofcom.org.uk. Retrieved on 2007-06-02.^ Common Filing Task: Obtaining Vanity Call Sign. FCC.gov. Retrieved on 2007-06-02.^ http://vkfaq.ampr.org/faq2lic.html Australian Radio Amateur FAQ^ FCC K7UGA record. General References Straw, R Dean (ed.) (October 2005). The ARRL Handbook for Radio Communications 2006, 83rd edition, Newington, CT: American Radio Relay League. ISBN 0-87259-949-3. OCLC 62026192. Bergquist, Carl J (2001-05-01). Ham Radio Operator's Guide, 2nd edition, Indianapolis: Prompt Publications. ISBN 0-7906-1238-0. OCLC 47051066. Dennison, Mike and Chris Lorek (eds.) (June 2005). Radio Communication Handbook, 8th edition, Potters Bar, Hertfordshire, England: Radio Society of Great Britain. ISBN 1-90508608-3. OCLC 123027893. Poole, Ian D (2001-10-31). HF Amateur Radio. Potters Bar, Hertfordshire, England: Radio Society of Great Britain. ISBN 1-872309-75-5. OCLC 47823876. [edit] See also