radiotelegraphy

radiotelegraphy
/ray'dee oh teuh leg"reuh fee/, n.
the constructing or operating of radiotelegraphs.
[1895-1900; RADIO- + TELEGRAPHY]

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      radio communication by means of Morse Code or other coded signals. The radio carrier is modulated by changing its amplitude (amplitude modulation), frequency, or phase in accordance with the Morse dot-dash system or some other code. At the receiver the coded modulation is recovered by an appropriate demodulator and the code groups are converted into the corresponding symbols. In many instances the symbols are generated by a computer and modem rather than with a manual telegraph key.

      Because radiotelegraphy uses a narrow frequency bandwidth, it allows effective communication to be carried out in the presence of interference and noise that would make other types of communication, such as radiotelephony, impractical. Radiotelegraphy is used for certain types of marine ship-to-shore communication (such as emergency calls), for weather and sea state bulletins by national maritime services, for point-to-point communication between fixed points on the Earth's surface, for amateur radio communications, and for various special services that do not require high-speed transmission of information, such as beacons, time signals, and data collection from remote sites.

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Universalium. 2010.

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  • radiotelegraphy — noun see radiotelegraph …   New Collegiate Dictionary

  • radiotelegraphy — noun The process and techniques of sending telegrams using radio waves rather than wires …   Wiktionary

  • radiotelegraphy — n. process of transmitting telegraphs or messages via radio waves …   English contemporary dictionary

  • radiotelegraphy — ra·dio·telegraphy …   English syllables

  • radiotelegraphy — /ˌreɪdioʊtəˈlɛgrəfi/ (say .raydeeohtuh legruhfee) noun telegraphy without wires or cables, in which messages are transmitted through space by means of the radiated energy of electromagnetic waves; wireless telegraphy …  

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  • Telegraphy — (from the Greek words (τηλε) = far and (γραφειν) = write) is the long distance transmission of written messages without physical transport of letters. Radiotelegraphy or wireless telegraphy transmits messages using radio. Telegraphy includes… …   Wikipedia

  • Radio — Äther; Rundfunk; Hörfunk; Funk; Radiogerät; Radioempfänger; Rundfunkgerät; Radioapparat * * * Ra|dio [ ra:di̯o], das; s, s: a) <ohne Plural> Rundfunk: das …   Universal-Lexikon

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