(Redirected from Ham radio)
Amateur radio, commonly called "ham radio", is a hobby enjoyed by many people throughout the world; about 3 million worldwide, 70,000 in Germany, 5,000 in Norway, 57,000 in Canada, and 700,000 in the USA. Owners of an Amateur Radio license have studied and passed required tests in their country and are then issued a call sign by their government. This call sign is unique to that person and is often a source of pride. The holder of a call sign uses it on the air to legally identify all voice and data communications. Amateur Radio should not be confused with CB radio which is limited to voice operation, allowed lower power limits, fewer frequency allocations, and is unlicensed in most countries.
The International Telecommunication Union (ITU) governs the allocation of communications frequencies world-wide, with participation by each nation by representation from their communications regulation authority. IARU member nations may choose to further limit specific frequency allocations within IARU guidelines.
Many countries have their own national Amateur Radio society that coordinates with the communications regulation authority for the benefit of all Amateurs. The oldest of these societies is the Wireless Institute of Australia (WIA), formed in 1910; other notable early societies are the Radio Society of Great Britain founded in 1913 and the American Radio Relay League created in 1914. National societies also cooperate through the International Amateur Radio Union (IARU).
Through ITU agreement bandwidth has been set aside for amateur transmissions. Amateurs use a varies of transmission modes, including Morse code, radio teletype, digital, and voice. Specific frequency allocations are a matter of record and vary from country to country and region to region, but the most widely used frequency allocations in the USA include:
There are other amateur radio bands as well, covering frequencies as low as 135 kHz and as high as 300 GHz and above.
Licensed Amateur Radio operators enjoy personal two-way communications with friends, family members, and complete strangers, all of whom must also be licensed. They support the larger public community with emergency and disaster communications. Increasing a person's knowledge of electronics and radio theory as well as radio contesting are also popular aspects of this radio service. A good way to get started in Ham Radio is to find a club in your area to answer your questions and provide information on getting licensed and then getting on the air!
Ham Radio offers the licensed operators a variety of radio modes that help to ensure reliable communications during and after disasters. Many of these rely on the "simplex" mode, that is direct, radio-to-radio, avoiding the problems associated with networks that might fail. In Ham Radio simplex communications would allow skilled radio operators to talk across town on VHF or UHF frequencies, or across the world on the HF (shortwave) bands of frequencies. Hams also have another powerful tool available, repeaters. Repeaters are radio relay devices usually located on the top of a mountain or tall building. A repeater allows the licensed Ham to have radio coverage for hundreds of miles from just a small handheld or mobile two-way radio.
Within amateur radio, one can pursue interests such as providing communications for a community emergency response team; antenna theory; satellite communication (see AMSAT and OSCAR series satellites); disaster response; Skywarn; packet radio (using data transmission protocols similar to that used on the internet, but via radio links); DX communication over thousands of miles using the ionosphere to refract radio waves; Internet Radio Linking Project (IRLP) which is a composite network of radio signals and the internet; and super low-power or QRP operation.
One of the many exciting activities of ham radio is the DX-pedition. Radio amateurs collect QSL cards from other stations, indicating the continents and regions which they have contacted. Certain zones of the world have very few radio amateurs. As a result, when a station with a rare ID comes on the air, radio amateurs flock to communicate with it. To take advantage of this phenomenon, groups of hams transport radio equipment into a remote country or island (such as normally uninhabited Bouvet Island, which has the rare callsign prefix 3Y). These expeditions can help hams quickly achieve a communication award such as a DXCC. To obtain the DXCC award a ham needs confirming QSL cards from hams in 100 countries around the world.
Contesting is another activity which has garnered interest in the ham community. During a period of time (normally 24 to 48 hours) a ham tries to successfully communicate with as many other hams as possible. The contesting amateur may concentrate on just DX stations, or only on stations powered by emergency generation equipment or running on batteries. The contest may or may not be limited in allowable modes of transmission.
Some hams use VHF or UHF frequencies to bounce their signals off the moon. The return signal is heard by many other hams who also do EME (earth-moon-earth). The antenna arrays are massive so a lot of real estate is needed. Other hams transmit with very low power. Signals on the order of 5 watts or less are heard all over the world by these QRP (low power) operators.
Despite all these exciting specialties, many hams enjoy the informal contacts, long discussions or "rag-chews", or round table "nets", whether by voice transmission (SSB, AM, or FM), CW (morse telegraphy), or one of the digital modes (RTTY, PSK31, and others).
Even with the advent of the internet (offering email, music, broadcast audio, video, voice over IP VoIP) ham radio is not diminishing in countries with advanced communications infrastructure. Amateur radio remains strong even today, as figures from the American Radio Relay League will prove.
In times of crisis and natural disasters, ham radio may be the only surviving means of communication.
On March 18, 1909 Einar Dessau used a short-wave radio transmitter which made him the first to broadcast as a ham radio operator.
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Tony Hancock's 1960 BBC TV episode "The Radio Ham", in which he plays an incompetent ham radio operator, has remained popular in the UK and has played a small part in keeping the memory of ham radio's heyday alive.
Hollywood movies have also used Amateur Radio as a convenient and often fanciful part of their plot:
 Now You're Talking!: All You Need to Get Your First Ham Radio License (Now Youre Talking, 5th Ed) |
 Passport to World Band Radio: 2004 (Passport to World Band Radio, 2004) |
 40 Watts from Nowhere : A Journey into Pirate Radio |
 World Radio TV Handbook 2004: The Directory of Global Broadcasting | ||||
 Say Again, Please: Guide to Radio Communications |
 Radio: An Illustrated Guide |
 Darwin's Radio : In the next stage of evolution, humans are history... |
 Trans-Sister Radio | ||||
 The Voice on the Radio |
