Electrical Communications

Военный термин: электрические средства связи

தொடர்புவலைவேலை (முறை)

сокр IUE-CWA

SUBJECT AREA: Broadcasting, Electronics and information technology, Telecommunications

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Hartley obtained his BA in 1909 from the University of Utah, then gained a Rhodes Scholarship to Oxford University, England. After obtaining a further BA and a BSc in 1912 and 1913, respectively, he returned to the USA and took a job with the Western Electric Laboratories of the Bell Telephone Company, where he was in charge of radio-receiver development. In 1915 he invented the Hartley oscillator, analogous to that invented by Colpitts. Subsequently he worked on carrier telephony at Western Electric and then at Bell Laboratories. There he concen-trated on information theory, building on the pioneering work of Nyquist, in 1926 publishing his law that related information capacity, frequency bandwidth and time. Forced to give up work in 1929 due to ill health, he returned to Bell in 1939 as a consultant on transmission problems. During the Second World War he worked on various projects, including the use of servo-mechanisms for radar and fire control, and finally retired in 1950.

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— air means

— air mobility means

— alternative means

— artillery means

— assistance means

— AT means

— auxiliary means

— backup means

— collection means

— collective protective means

— common delivery means

— communications means

— communications-electronics means

— control means

— conventional warfare means

— covert means

— crossing means

— CW means

— defense means

— delivery means

— destruction means

— electrical communications means

— emergency means

— environmental warfare means

— EO reconnaissance means

— expedient means

— fire means

— fire support means

— gathering means

— geophysical means of influencing the environment

— ground mobility means

— identification means

— impromptu means

— improvised means

— individual protective means

— inspection and verification means

— logistical means

— military means

— mobility means

— mounted auxiliary propulsion means

— national technical control means

— naval means

— nonnuclear means

— nuclear delivery means

— nuclear warfare means

— organic means

— overt means

— physical security means

— protection means

— radar means

— radio electronic means

— relinquish attached means

— self-protection means

— strategic deterrent delivery means

— supporting means

— surveillance means

— tank-stopping means

— transport means

— ultimate delivery means

— verification means

— warfare means

— warning means

— world-wide delivery means

SUBJECT AREA: Telecommunications

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Following early education at Phillips Academy, Andover, at the age of 14 years Morse went to Yale College, where he developed interests in painting and electricity. Upon graduating in 1810 he became a clerk to a Washington publisher and a pupil of Washington Allston, a well-known American painter. The following year he travelled to Europe and entered the London studio of another American artist, Benjamin West, successfully exhibiting at the Royal Academy as well as winning a prize and medal for his sculpture. Returning to Boston and finding little success as a "historical-style" painter, he built up a thriving portrait business, moving in 1818 to Charleston, South Carolina, where three years later he established the (now defunct) South Carolina Academy of Fine Arts. In 1825 he was back in New York, but following the death of his wife and both of his parents that year, he embarked on an extended tour of European art galleries. In 1832, on the boat back to America, he met Charles T.Jackson, who told him of the discovery of the electromagnet and fired his interest in telegraphy to the extent that Morse immediately began to make suggestions for electrical communications and, apparently, devised a form of printing telegraph. Although he returned to his painting and in 1835 was appointed the first Professor of the Literature of Art and Design at the University of New York City, he began to spend more and more time experimenting in telegraphy. In 1836 he invented a relay as a means of extending the cable distance over which telegraph signals could be sent. At this time he became acquainted with Alfred Vail, and the following year, when the US government published the requirements for a national telegraph service, they set out to produce a workable system, with finance provided by Vail's father (who, usefully, owned an ironworks). A patent was filed on 6 October 1837 and a successful demonstration using the so-called Morse code was given on 6 January 1838; the work was, in fact, almost certainly largely that of Vail. As a result of the demonstration a Bill was put forward to Congress for $30,000 for an experimental line between Washington and Baltimore. This was eventually passed and the line was completed, and on 24 May 1844 the first message, "What hath God wrought", was sent between the two cities. In the meantime Morse also worked on the insulation of submarine cables by means of pitch tar and indiarubber.

With success achieved, Morse offered his invention to the Government for $100,000, but this was declined, so the invention remained in private hands. To exploit it, Morse founded the Magnetic Telephone Company in 1845, amalgamating the following year with the telegraph company of a Henry O'Reilly to form Western Union. Having failed to obtain patents in Europe, he now found himself in litigation with others in the USA, but eventually, in 1854, the US Supreme Court decided in his favour and he soon became very wealthy. In 1857 a proposal was made for a telegraph service across the whole of the USA; this was completed in just over four months in 1861. Four years later work began on a link to Europe via Canada, Alaska, the Aleutian Islands and Russia, but it was abandoned with the completion of the transatlantic cable, a venture in which he also had some involvement. Showered with honours, Morse became a generous philanthropist in his later years. By 1883 the company he had created was worth $80 million and had a virtual monopoly in the USA.

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