What is Amateur Radio?
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Main article: Ham Radio. What is it and why do they do it?
Amateur radio, also known as ham radio, is both a hobby and a service in which participants, called "hams," use various types of radio communications equipment to communicate with other radio amateurs for public service, recreation and self-training.
Amateur radio operators enjoy personal (and often worldwide) 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.
The term "amateur" is not a reflection on the skills of the participants, which are often quite advanced, reaching far in the fields of physics, electronics and circuit design and engineering; rather, "amateur" indicates that amateur communications are not allowed to be made for commercial or money-making purposes. Ham, on the other hand, is another question, see Why call it ham radio?
How do ratio operators communicate?
Main article: Propagation
Communication is possible with other stations operated on all continents. Operators can also use relays, on the ground or in space (operators can talk with the space station!) or use Sky waves and lower frequencies (paradoxically called High Frequency, HF instead of VHF or UHF) to bounce around the earth and communicate across oceans and continents. They will also listen to various beacons. All this is using different radio apparatus including antennas and transceivers but also software and computers.
Modes of operation
Main article: Modes
Amateur Radio operators use various modes of transmission to communicate either locally or across the world or even space.
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, at the sacrifice of audio quality.
Carrier wave (CW AKA morse code) dates from the earliest days of radio. It used to be a requirement in order to have access to lower frequencies (HF) or even to get a license to operate at all, in some locations. While this is no longer the case since 2003, Morse code is still very popular with QRP operators.
Digital modes, made possible with the use of personal computers. This group includes:
- radioteletype (RTTY)
- packet radio, which has employed protocols such as TCP/IP since the 1970s.
- PSK31 allow real-time, low-power communications on the shortwave bands.
- Echolink using Voice over IP technology.
- IRLP has allowed the linking of repeaters to provide greater coverage area.
- FSK441 using software such as WSJT, are used for weak signal modes including meteor scatter and moonbounce communications.
- Fast scan amateur television (ATV)
- Slow scan television (SSTV)
Bands of operation
Amateur radio has been allocated specific radio frequencies in the spectrum for its own use. The above modes can therefore be used on many different frequencies. There are conventions within the ham community regarding which frequencies are appropriate for what. This is called the band plan. It varies according to regions, but there's an international convention that most countries respect. The reason behind those conventions is that certain ranges of frequency (also called bands) have certain properties that make it more suitable for certain communications. For example, the 20m band (~14Mhz) is good for worldwide communication, day and night, while 70cm (~440Mhz) is good to communicate in line of sight or with satellites, as it doesn't bounce of the ionosphere.
A callsign is a unique identifier, issued by the amateur's national government. The operator uses the callsign to identify himself/herself during radio transmissions.
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 and may also indicate the license class. (This callsign is licensed in South Africa, and is CEPT Class 1). 1 – Gives 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 license, identifying that person specifically.
Not all countries follow ITU recommendations for callsign structure.
Amateur radio on the big screen
- Men of Boys Town (1941), starring Spencer Tracy and Mickey Rooney.
- If All the Guys in the World (original title "Si tous les gars du monde..." (1957). A French film largely devoted to Amateur Radio.
- Tony Hancock's 1960 BBC TV episode "The Radio Ham", in which he plays an incompetent ham radio operator.
- Star Wars (1977).
- The French Atlantic Affair (1979)
- Phenomenon (1996) starring John Travolta.
- Contact (1997) starring Jodie Foster.
- The Sweet Hereafter (1997) starring Ian Holm.
- Frequency (2000) starring Jim Caviezel and Dennis Quaid.
- Bob's White Christmas (2001) starring Bob the Builder and his brother Tom.
- Space Station (2001). An IMAX film
|Operation||Callsigns and ITU prefixes * Codes and Alphabets * Modes * Morse code * Nets * UK licensing * Terminology|
|DX and Contesting||Awards and Certificates * DXCC * DX cluster * Field day * Gridsquares * Logging * QSL and QSL Bureaus * Records - Distance|
|Emergencies||Emergency Frequencies * ARES * IRESC * SATERN * Weather spotting|
|Utilities||Beacons (/B) and Time Beacons|