It is many different things to the individual more than two million people throughout the world who enjoy this multi-faceted communications hobby.
Below is a summary of how it began and has kept with the times to remain an enjoyable leisure time activity. In Australia, the Foundation Licence has made it more accessible to those who have an interest in communicating, learning new skills and making friends.
Who are radio amateurs?
They are ordinary citizens, including some of your neighbours or work colleagues, and people in more than 100 countries. They are radio amateurs - also known as ham operators, or amateur radio operators.
Many years ago it was common to hear the description "From newspaper boys to Kings" in reference to Amateur Radio - and it simply meant that radio amateurs range from newspaper boys (street sellers of daily newspapers) to Kings, with royalty being among the ranks of ham operators.
In today's terms we can say that Amateur Radio is enjoyed by people with all types of backgrounds, age groups, and having all abilities, who meet on the airwaves for a chat or engage in other interesting activities.
One of the marvellous things about the hobby is that radio signals don't stop at country borders - being a radio amateur is like having an international passport.
You can visit the world on the airwaves, make casual acquaintances or life-long friendships, without even leaving home. Many long-time radio amateurs will tell you that some of their best friends are people they have never met in person.
Around the world radio amateurs have set up their own transmitting and receiving stations at home, in their cars, and even use hand-held radios to keep in touch while on foot. The friends they make could be someone across town, in a far-flung exotic country, or even astronauts on the International Space Station or Space Shuttle missions who are radio amateurs too!
How do radio amateurs contact each other?
When the hobby began around the turn of the 19th century the only form of communication radio amateurs (they were then known as amateur wireless experimenters) was Morse code, the same method used by the telegraph.
This form of communication has survived to still be in use today - and has become an international language enabling people who can't speak the same language, to communicate.
Up until the 1920's wireless telegraphy was the only way to transmit and receive information on the airwaves. But radio amateurs pioneered voice communications in the mid-1920s at the time when broadcast stations began.
Although the transmission and reception techniques have changed over the years with technical developments, voice communication remains the major method of communicating on the amateur bands.
In times of natural disasters, radio amateurs throughout the world provide support communications, and sometimes the only communications immediately after a disaster.
When Cyclone Tracey hit Darwin in 1974 virtually the only communication out of the area was by a radio amateur who hooked his transceiver up to a car battery, and let the world know that Darwin needed help.
Also in Australia, emergency communications have been provided after numerous bush fires including Black Friday 1939, and Ash Wednesday 1983. Another occasion was after the Newcastle Earthquake in 1989.
More recently radio amateurs provided vital communications immediately after the Indian Ocean tsunami disaster that affected India, Sri Lanka, Thailand and Indonesia. Often after a disaster normal telephone systems are damaged or jammed as anxious relatives try and call an area.
The radio systems of emergency services are also extremely busy, and additional or supplementary communication can be readily provided by radio amateurs using their own equipment, and skills.
The role of the Wireless Institute Civil Emergency Network (WICEN) to supply communications in times of emergency is recognised in the State Disaster Plan.
WICEN is an organised group of radio amateurs who regularly engage in training exercises, and provide communication for public events such as car rallies, the great Victorian Bike Ride, and the Red Cross Murray River Canoe Marathon.
The linking of computers to Amateur Radio has become popular. Often it is done using the soundcard on a PC and software. There are several operating modes, each having its particular use. Mostly they provide keyboard communications.
If you would like to know more, do some research on PSK31, WSJT. The use of digitised voice via Amateur Radio is also expected to become common in the near future. The IRLP (internet radio linking project) and EchoLink are linking radios via cyberspace, with amateur stations being linked across the internet.
The sending of pictures via radio was being done by radio amateurs long before television began in Australia in 1956.
This interesting aspect of Amateur Radio has several variations, from single-frame pictures through to full-colour real-time video that can be received on a domestic television receiver with UHF capabilities. There is also software available that permits fax to be sent over the radio.
Soon after the launch by the former Soviet Union of Sputnik 1, the world's first man-made orbiting satellite, radio amateurs entered the space age with the OSCAR (Orbiting Spacecraft Carrying Amateur Radio) series of satellites.
The tradition of designing and building amateur satellites continues today. They are being launched as a piggyback load when major communications satellites are put into orbit. International contacts are possible by sending a signal to a satellite and having it relayed back to earth providing communications over many thousands of kilometres.
The Fox, the Hounds, and Amateur Radio
The methods used to determine, at a distance, the source of a transmitted signal, are broadly as direction finding (DF), and have application in navigation systems.
But radio amateurs also effectively use DF when they take part in a popular activity called Foxhunting. This involves locating within a time limit a small hidden transmitter.
In some countries DFing is called Radio Sport, and involves a lot of footwork over reasonably lengthy courses, and is likened to a mix of DFing and another sport - orienteering.
However Foxhunting in Australia often includes travel in a car, and DFing a hidden transmitter while on the move. Then the Foxhunters, or Hounds as they're known, become pedestrians to discover the hiding spot of the transmitter, and you guessed it is called the Fox.
Foxhunts can also be held over relatively short courses requiring Hounds to do all of their DFing while on foot.
Foxhunting basically uses a directional beam antenna, both vehicle mounted or out-the-window, and receiver to DF the general hiding spot of the Fox.
Then most Hounds use a special receiver called a "Sniffer" with variably sensitivity, to virtually sniff out the Fox. Numerous cunning tricks are played by those hiding a Fox as they seek to elude the Hounds.
A regular Foxhunting Championship series is held on one Friday a month in metropolitan Melbourne during the Foxhunting season. A dozen or teams join in. Enthusiastic newcomers are often able to find the Fox ahead of some of the more experienced competitors.
Want to experience the fun of Foxhunting? This can be arranged - even if you don't yet have an amateur radio licence. The Melbourne Foxhunters will offer a very warm welcome, and let you go along for the ride. Contact Amateur Radio Victoria to ask for more details.
QRP is a real personal challenge
Would you expect the light from a small torch (equal to the energy radiated by five candles, or about 50 with the use of a reflector) which is switched on in Melbourne, to be seen in Sydney, Brisbane, or America?
Of course not! Yet in radio terms such a thing is possible and happens as one of the many facets of Amateur Radio.
This is the world of "QRP" or Low Power Operation, where the goal is to reach as far as you can with as little transmitter power as possible.
Why? Yes, it seems strange when 100 watts is the norm, to want to transmit with five watts or much less - milliwatts. But it is the challenge of making your antenna as efficient a radiator as possible.
You may also like the challenge of making your own radios. QRP is a challenge to succeed with limited resources, and for many of its devotees it satisfies their desire to experiment, learn, and have fun.
And there's much more!
Contests, awards, QSLing, eyeball-QSOs, hamventions, special event stations, skills that can be used at work or school, and the list goes on.