Amateur radio
Amateur radio, often called Ham radio, is a hobby and public service enjoyed by about 6 million people throughout the world. An amateur radio operator, also known as a ham or radio amateur, uses advanced radio equipment to communicate with other radio amateurs for public service, recreation and self-training.
As used in this case, the legal term "Amateur" does not connote lack of skill, but simply indicates that the frequencies involved cannot be used for commercial purposes. In fact, a person usually has to pass an examination proving their skill before being licensed as an Amateur Radio Operator by their nation's government.
Amateur radio operators enjoy personal wireless communications with friends, family members, and even complete strangers. They support the community with emergency and disaster communications. Increasing a person's knowledge of electronics and radio theory and radio contesting are also popular.
Amateur radio activities and practices
Radio amateurs use many 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, with its inherent signal-to-noise ratio advantages. Morse, using internationally agreed code groups, also facilitates communications between amateurs who speak different languages[citation needed]. It is also popular with home constructors as CW-only transmitters are simpler to construct.
Modern personal computers have led to a boom in digital modes such as radioteletype, which previously required cumbersome mechanical equipment[citation needed]. Hams led the development of packet radio, which has since been augmented by more specialized modes such as PSK31 to facilitate real-time, low-power communications on the shortwave bands. Other modes, such as WSJT, are used for weak signal modes including meteor scatter and moonbounce communications.
Similarly, fast scan amateur television, once considered rather esoteric, has exploded in popularity thanks to cheap camcorders and video cards in home computers. Because of the wide bandwidth and stable signals required, fast scan amateur television is normally limited to 100 km (about 60 miles) range.
On VHF and higher frequencies, automated relay stations, or repeaters, are used to increase range. Repeaters are usually located on the top of a mountain or tall building. A repeater allows the radio amateur 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, wireline, or the Internet.
While many hams just enjoy talking to friends, others pursue specialized interests such as providing emergency communications for community emergency response teams; designing new antennas; communicating via amateur satellites; severe weather spotting; DX communication to far away countries; using the Internet Radio Linking Project (IRLP) to connect radio repeaters via the Internet; tracking vehicles using the Automatic Position Reporting System (APRS), which integrates with the GPS; engaging in the sports of Contesting, Amateur Radio Direction Finding and High Speed Telegraphy; or trying low-power operation.
Some enthusiasts collect vintage amateur radios, such as those using vacuum tube technology. Some hams also assist in the restoration and operation of antique radio equipment at museums and museum ships.
Many hams enjoy meeting each other in person as well through local clubs or at Hamfests. These annual events are popular, with the largest being held in Dayton Ohio, where more than 20,000 hams gather each May.
Emergency communications
In times of crisis and natural disasters, Amateur radio provides emergency communications when wireline, cell phones and other means of communications fail. Unlike commercial systems, Amateur radio is not dependent on terrestial facilities that can be destroyed [1]. It also dispersed throughout a community without "choke points" such as celluar telephone sites that can become overloaded [2].
Amateur radio operators are also experienced in improvising antennas and power sources and equipment can be powered by an automobile battery [3] . Annual "Field Days" are held in many countries to practice these emergency improvisational skills. Amateur radio operators can use hundreds of frequencies and can quickly establish networks tying disparate agencies together to enhance interoperability [4].
Recent examples include the 2001 attacks on the World Trade Center [5]the 2003 North America blackout, the 2004 Indian Ocean earthquake [6] and Hurricane Katrina, where amateur radio was used to coordinate disaster relief activities when other systems failed.
QSL cards
Traditionally, radio amateurs exchange QSL cards with other stations to confirm a conversation (QSO). These are required for many amateur operating awards, and many amateurs also collect them simply for the pleasure of doing so.
DXing
Many amateurs enjoy trying to contact stations in as many different parts of the world as they can on the shortwave bands, or over as great a range as possible on the higher bands, in a pursuit known as DXing (DX stands for Distance).
Awards
Operating awards are given to hams who contact (or "work") a certain number of distant stations. There are thousands of operating awards available. The most popular awards are the Worked All States award and the Worked All Continents award, and the more challenging Worked All Zones, DX Century Club (DXCC) and VHF/UHF Century Club (VUCC) awards. DXCC is the most popular awards program, initially requiring amateurs to contact 100 of the (as of 2006) 337 recognized countries and territories in the world. Other popular awards include contacting remote islands, US counties, and lighthouses. Many awards are available for contacting amateurs in a particular country, region or city.
DX-peditions
Certain places have very few radio amateurs. As a result, when a station is heard from these rare areas, other radio amateurs flock to communicate with it. Often amateurs will travel specifically to a rare country or island in a DX-pedition to activate it. Big DX-peditions can communicate with as many as 100,000 individuals in a few weeks.
Special event stations
Many amateurs also enjoy setting up and contacting special event stations. Set up to commemorate special occurrences, they often issue distinctive QSLs or certificates. Some use unusual prefixes, such as the call signs with "96" that amateurs in the US State of Georgia could use during the 1996 Atlanta Olympics[citation needed], or the OO prefix used by Belgian amateurs in 2005 to commemorate their nation's 175th anniversary [7]. Some events are held annually such as Guides on the Air and Jamboree on the Air. Many amateurs decorate their radio "shacks" (the room where they keep their radio) with these certificates.
Hamfests
A hamfest is a social event for hams and their families; most are one-day events but some are multiple days. The highlight of any hamfest is the swap meet where hams sell, swap and buy radios and related equipment, either indoors at tables or in outdoor "tailgate" areas. Some swap meets are very large, covering several acres; the largest in the US is at Dayton, Ohio each year in May. Most hamfests have additional activities such as lectures, demonstrations and activities for non-ham attendees and door prize drawings. Many hamfests feature testing sessions at which attendees can obtain or upgrade their license. Some hamfests are held in conjunction with conventions of the ARRL. Most hamfests are listed in QST magazine[citation needed], the official ARRL journal devoted entirely to Amateur Radio.
Contesting
Contesting, also known as radiosport, is a competitive activity pursued by amateur radio operators. In a contest, an amateur radio station, which may be operated by an individual or a team, seeks to exchange information with as many other amateur radio stations as possible in a given period of time. Rules for each competition define the amateur radio bands that may be used and the information that must be exchanged in each contact. These contacts contribute to a score to determine the winner. Contest sponsors publish the results in magazines and on web sites. Over time, the number and variety of radio contests has increased, and many amateur radio operators today pursue the sport as their primary amateur radio activity.
Round table discussion groups
Many Amateur radio operators enjoy participating in round table discussion groups or "Rag Chew Sessions" on the air. These discussion groups have been a mainstay of Amateur radio since its inception.
Round table discussion groups are often configured to allow the conversation to pass from one participant to another. The participants spend time developing and presenting their thoughts as the conversation passes from one person to another much as conversation would flow at a dinner table. The conversation usually revolves around topics related to radio, however, there is no limit to their scope.
Nets
Many round tables meet in a regularly scheduled on-air meeting with other amateur radio operators, called a "Net" which is moderated by a station referred to as "Net Control" [8]. Nets can allow operators to learn Net control procedures for emergencies, could be an informal round table, or may be topical, covering specific interests shared by the group. Many Nets feature audio news reports such as Amateur Radio Newsline. Since many local club FM repeaters host Nets, it is often the first large-scale activity for new hams, who can participate with just an HT.
Portable operations
Licensed amateurs often take portable equipment with them when traveling. On long-distance expeditions, such equipment allows them to report progress, arrivals and sometimes exchanging safety messages along the way.
Many hams at fixed locations are pleased to hear from such travelers. For a ham in a yacht in mid-ocean or a 4x4 inside the Arctic Circle, a friendly voice and the ability to relay a message home or call for help is a welcome comfort.
See maritime mobile amateur radio for further details about amateur radio operation at sea.
Some countries allow the direct connection of amateur transceivers to telephone lines called "phone patching" [9]. Thus, a traveler may be able to call another amateur station and, via a phone patch, speak directly with someone else by telephone.
Storm spotting
Where severe storms are possible, storm spotting groups such as SKYWARN in the United States coordinate amateur radio operators to keep track of severe thunderstorms and tornadoes. Reports from spotters and chasers are given to the National Weather Service to warn the general public. Spotters also give reports during winter storms, floods, hurricanes and wildfires. Other countries have similar programs, such as the Canadian spotting program CANWARN.
Low power operations
Some hams enjoy the construction and operation of low-power transmitters. This activity is called QRP which is the international Q code for "reduce power". QRP operators use 5 watts output or less on Morse Code and 10 watts on voice.
VHF, UHF and microwave operation
Amateur radio VHF, UHF and microwave frequencies above 30 MHz allow radio amateurs to communicate locally. While many radio amateurs use modest equipment on VHF or UHF frequencies, others use more sophisticated systems to communicate over as wide a distance as possible. The 2-meter band (144-148MHz) is the most popular Amateur Radio band [10].
One technique to communicate over long distances is to use the surface of the moon as a passive reflector. Earth-Moon-Earth operation, or EME, allows communications between any two places on the earth which can see the moon at the same time.
Amateurs also operate on frequencies in the microwave region. The most popular is the 2.4 GHz band using WiFi cards and gain antennas to establish what is called the Hinternet. In countries such as the United States, amateur radio operators can add amplifiers not available to the general public to operate higher power on these bands allowing them to send data at high speeds (in the MegaBit per Second range) between locations up to 50 miles away.
Space operations
Over 70 communication satellites have been launched into earth orbit for amateur radio use. Called OSCARs or Orbiting Satellite Carrying Amateur Radio, some can even be accessed using a handy-talkie (HT) with a stock "rubber duck" antenna. One of the newer OSCAR satellites—AO-51 (previously known as AMSAT Echo) can be operated in this manner. Hams also use natural satellites such as the moon and meteors to aid in radio wave propagation [11].
Hams are also often able to make contact with the International Space Station (ISS) [12], as many astronauts and cosmonauts are licensed as Amateur Radio Operators [13] to assist in student education programs and for emergency back-up communications.
Amateur radio licensing
In all countries, amateur radio operators are required to pass an exam displaying knowledge and understanding of key concepts. This practice is in contrast to other personal radio services such as CB radio, Multi-Use Radio Service, or Family Radio Service / PMR446 that are unlicensed and more heavily restricted. In return, hams are granted operating privileges in larger segments of the radio frequency spectrum using a wide variety of communication techniques. Hams are also allowed to use equipment that they have either built themselves or modified. This privilege is unavailable in virtually any other radio service.
Getting started
Many people become started in amateur radio by finding a local club. Clubs can provide information about licensing, local operating practices and technical advice. (See Category: Amateur radio organizations) They also may study independently by purchasing books or other materials.
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. These beginner's licenses are referred to as Foundation Licenses.
In some countries, however, amateur radio licensing is very bureaucratic (for example in India) or challenging because some applicants must undergo difficult security approval (as in Iran). Currently only the nations of Yemen and North Korea do not permit their citizens to operate amateur radio stations at all, although in both cases a few visiting foreign amateurs have been granted temporary operating authority.
In some developing countries, licensing fees can be prohibitive in terms of local incomes. This is a particular problem in Africa and to a lesser extent in poorer parts of Asia and Latin America and the Caribbean. Small countries or those with weak administrative structures may not have a national licensing scheme and may require amateurs to take the licensing exams of a foreign country in lieu.
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. Some licenses also require knowledge of Morse Code, but in 1991 the Federal Communications Commission created a "No-Code Technician" license which allowed privileges on all bands above 30 MHz. The FCC will eliminate the Morse Code testing requirement for all classes of license sometime in 2007. This is in keeping with changes in international law, which no longer mandates Morse Code testing before using the HF bands, as well as a view by the FCC that the code requirement serves as an advancement barrier to otherwise qualified individuals. The portions of the ham bands restricted to CW only and voluntary use of the mode will remain.
When licensed
After licensing, a radio amateur's local 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[1]. In certain jurisdictions, once licensed, an operator may also opt for a vanity callsign for a fee[2].
Privileges of the amateur
In contrast to most commercial and personal radio services, radio amateurs are not restricted to using type-approved equipment, and some radio amateurs home-construct or modify equipment in any way 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 facilitate 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 permitted power levels are moderate by commercial standards, they are sufficient to enable global communication. Power limits vary from country to country. For example, the highest license classes are: 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, 400 watts in the United Kingdom, 300 watts in Italy 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.
In the United States, the Federal Communications Commission licenses operators in the Amateur Service to promote radio experimentation, to provide public service, and to maintain a pool of trained operators. In exchange for passing the federal test, licensed operators are allowed to use some 1300 distinct modes of communications at effective radiated power levels ranging from microwatts to thousands of watts.
International licensing and operation
When traveling abroad, the visiting ham must follow the rules of the country in which she or he wishes to operate. Some countries have reciprocal operating agreements allowing hams from other countries to operate within their borders with just their home country license. Others require that a formal permit or new license be issued in advance.
Governance and amateur radio societies
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.
Many countries have their own national amateur radio society that coordinates with the government's communications regulation authority for the benefit of all 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.
Band plans and frequency allocations
Through ITU agreement, frequencies have been set aside for amateur radio. Using allocated frequencies as a basis of planning, national telecommunication agencies decide which of the international allocations can be used within their borders. National amateur radio societies often have band plans to further divide those allocations, often by use.
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.
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.
History
The birth of amateur radio and radio in general was mostly associated with various amateur experimenters. 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.
Amateur radio in popular culture
Amateur radio can be found throughout popular culture as a plot device. An example from Hollywood is the 2000 film Frequency. In this romantic sci-fi, the two main characters, a father and son (played by Dennis Quaid and Jim Caviezel respectively), communicate via the same amateur radio, one of them living in 1969 and the other in 1999. This communication is, of course, impossible, but was used as a plot device. A wealth of additional information may be found at the main article link shown above.
Another example would be the "Radio Ham" episode of 1960s British comedy series "Hancock's Half Hour".
There are also famous Amateur radio operators such as King Juan Carlos I of Spain, radio host Walter Cronkite, and Coast To Coast AM host Art Bell. Others include the late Gen. Curtis LeMay, Joe Walsh, Lance Bass, the late Barry Goldwater, the late Chet Atkins, the late Marlon Brando, King Hussein of Jordan, Patty Loveless, Ronnie Milsap, Bill "Bubba" Bussey from the nationally syndicated Rick and Bubba Show, and Jean Shepherd, as well as almost every one of the launched astronauts and cosmonauts.
See also
References
- Cited References
- General References
- American Radio Relay League (2006). The ARRL Handbook for Radio Communications 2006. 83rd Edition. Newington, Connecticut, USA: American Radio Relay League. ISBN 0-87259-949-3.
- Bergquit, Carl (2001). Ham Radio Operator's Guide. Second Edition. Prompt Publishing, 2001. ISBN 0-7906-1238-0.
- Dennison, Mike and Lorek, Chris, eds. (2006). RSGB Radio Communication Handbook. 8th Edition. Radio Society of Great Britain. ISBN 1905086083 .
- Poole, Ian (2001). HF Amateur Radio. Radio Society of Great Britain. ISBN 1-872309-75-5