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  • Amateur radio


    An example of an amateur radio station with four transceivers, amplifiers, and a computer for logging and for digital modes. On the wall are examples of various amateur radio awards, certificates, and a reception report card (QSL card) from a foreign amateur station.Amateur radio, also known as ham radio, describes the use of radio frequency spectrum for purposes of non-commercial exchange of messages, wireless experimentation, self-training, private recreation, radiosport, contesting, and emergency communication. The term "amateur" is used to specify "a duly authorised person interested in radioelectric practice with a purely personal aim and without pecuniary interest;" (either direct monetary or other similar reward) and to differentiate it from commercial broadcasting, public safety (such as police and fire), or professional two-way radio services (such as maritime, aviation, taxis, etc.). The amateur radio service (amateur service and amateur-satellite service) is established by the International Telecommunication Union (ITU) through the Radio Regulations.

  • Two-way radio


    Several modern two-way hand-held radios compatible with the Project 25 digital radio standard (Mobile and base station radios not shown) A two-way radio is a radio that can both transmit and receive a signal (a transceiver), unlike a broadcast receiver which only receives content. It is an audio (sound) transceiver designed for bidirectional person-to-person voice communication with other users with similar radios using the same radio frequency (channel). Two-way radios are available in mobile, stationary base and hand-held portable configurations. Hand-held two-way radios are often called walkie-talkies, handie-talkies or hand-helds. Two-way radio systems usually operate in a half-duplex mode; that is, the operator can talk, or he can listen, but not at the same time. A push-to-talk or Press To Transmit button activates the transmitter; when it is released the receiver is active. Other Full-duplex is generally achieved by the use of two different frequencies or by frequency-sharing methods to carry the two directions of the conversation simultaneously.

  • Portable operation (amateur radio)


    Portable equipment indicates a configuration that allows for relatively rapid collection, transportation, and deployment of amateur radio gear. Licensed operators often take part in portable operations using radio equipment when traveling. A portable station can be anything from a small QRP (Low Power) radio and antenna, to a top-of-the-line rig, space dependent. On long-distance expeditions, such equipment allows them to report progress, arrivals and sometimes exchanging safety messages along the way.Kamal Edirisinghe, 4S7AB, from Sri Lanka, operating a portable amateur radio station south of Stockholm, Sweden

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