O R A R I
Organisasi Amatir
Radio Indonesia
Zone 28 Oceania
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Amateur, or "ham," radio, a noncommercial system of communication, is as old as the medium
of RADIO itself. The origin of the term ham radio is unknown. Many important communications
discoveries have been made by hams. Amateurs, for example, perfected the single sideband
(SSB) mode, now widely used by the military, after World War II; in the late 1970s, three hams
developed the revolutionary new system of narrow-band voice modulation (NBVM). Both systems
offer great improvements over AMPLITUDE MODULATION and FREQUENCY MODULATION for
long-distance voice communication and have increased the number of stations that can use a
given portion of the radio spectrum.
Ham radio is mainly a hobby to most participants, but amateurs are perhaps best known for the
emergency communications they provide during hurricanes, floods, and other disasters until
regular communications are restored. Communications are sent primarily by voice or by
International MORSE CODE. A number of small communications satellites -- the Oscar series -- are
reserved for amateur use. The frequency allocations for
amateur radio were first designated by international treaty in 1927 and are shared with other
users.
To obtain an operating license, an amateur must pass a written exam in radio regulations and
basic radio technology. The ability to use Morse code was once also required of amateurs, but a
new class called "codeless technician" was added to the other four existing license classes. The
leading organization of amateurs in the United States and Canada, the American Radio Relay
League based in Newington, Conn., was founded in 1914 by Hiram Percy MAXIM and Clarence
Tuska.
[Stuart F. Crump, Jr.]
Bibliography:
American Radio Relay League, The Radio Amateur's Handbook (annual); Gibilsco,
Stan, The Encyclopedia of Amateur Radio (1993); Halprin, R. J., Ham Radio Contesting (1992);
Hood, W. E., How to Be a Ham, 3d ed. (1986).
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