18 Facts About Amateur radio

Amateur radio, known as ham radio, is the use of the radio frequency spectrum for purposes of non-commercial exchange of messages, wireless experimentation, self-training, private recreation, radiosport, contesting, and emergency communications.

Amateur radio service is established by the International Telecommunication Union through the Radio Regulations.

Radio amateurs are limited to a small set of frequency bands, the amateur radio bands, allocated throughout the radio spectrum, but within these bands are allowed to transmit on any frequency using a variety of voice, text, image, and data communications modes.

Origins of amateur radio can be traced to the late 19th century, but amateur radio as practiced today began in the early 20th century.

Amateur radio enthusiasts have significantly contributed to science, engineering, industry, and social services.

Ham Amateur radio can be used in the classroom to teach English, map skills, geography, math, science, and computer skills.

Many facets of amateur radio attract practitioners with a wide range of interests.

Some join in regularly scheduled on-air meetings with other amateur radio operators, called "nets", which are moderated by a station referred to as "Net Control".

Amateur radio operators, using battery- or generator-powered equipment, often provide essential communications services when regular channels are unavailable due to natural disaster or other disruptive events.

Many amateur radio operators participate in radio contests, during which an individual or team of operators typically seek to contact and exchange information with as many other amateur radio stations as possible in a given period of time.

All countries that license citizens to use amateur radio require operators to display knowledge and understanding of key concepts, usually by passing an exam.

Amateur radio licensing is a routine civil administrative matter in many countries.

An amateur radio license is valid only in the country in which it is issued or in another country that has a reciprocal licensing agreement with the issuing country.

In some countries, an amateur radio license is necessary in order to purchase or possess amateur radio equipment.

Prospective amateur radio operators are examined on understanding of the key concepts of electronics, radio equipment, antennas, radio propagation, RF safety, and the radio regulations of the government granting the license.

An amateur radio operator uses a call sign on the air to legally identify the operator or station.

Amateur radio operators are encouraged both by regulations and tradition of respectful use of the spectrum to use as little power as possible to accomplish the communication.

In former times, most amateur digital modes are transmitted by inserting audio into the microphone input of a radio and using an analog scheme, such as amplitude modulation, frequency modulation, or single-sideband modulation .