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 Radio history

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تاريخ التسجيل : 16/09/2008

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مُساهمةموضوع: Radio history   الجمعة فبراير 27, 2009 12:12 am

Twenty years
after the telephone was invented and music was first sent down a telephone
line,
Guglielmo Marconi sent radio signals.



Marconi (1874-1937)
was born in Italy and studied at the University of Bologna. He was fascinated
by Heinrich Hertz's earlier discovery of radio waves and realised that
it can be used for sending and receiving telegraph messages, referring
to it as "
wireless telegraphs."



Marconi's first
radio transmissions, in 1896, were coded signals that were transmitted
only about 1,6 km (a mile) far. Marconi realised that it held huge potential.
He offered the invention to the Italian government but they turned it
down. He moved to England, took out a patent, and experimented further.
In 1898 Marconi flashed the results of the Kingstown Regatta to the offices
of a Dublin newspaper, thus making a sports event the first "public"
broadcast. The next year Marconi opened the first radio factory in Chelmsford,
Essex and established a radio link between Britain and France. A link
with the USA was established in 1901. In 1909 Marconi shared the Nobel
prize in physics for his wireless telegraph. Marconi became a wealthy
man.



Signals only
But Marconi's wireless telegraph transmitted only signals. Voice over
the air, as we know radio today, came only in 1921. Marconi went on to
introduce short wave transmission in 1922.



Marconi was
not the first to invent the radio, however. Four years before Marconi
started experimenting with wireless telegraph,
Nikoli Tesla, a
Croatian who moved to the USA in 1884, invented the theoretical model
for radio. Tesla tried unsuccessful to obtain a court injunction against
Marconi in 1915. In 1943 the US Supreme Court reviewed the decision. Tesla
became acknowledged as the inventor of the radio - even though he did
not build a working radio.



Who then,
tell me?!
There are other claims to the throne of radio inventor.



Indian scientist Sir J.C.
Bose demonstrated the radio transmission in 1896 in Calcutta in front
of the British Governor General. The transmission was over a distance
of three miles from the Presidency College and Science College in Calcutta.
The instruments ('Mercuri Coherer with a telephone detector') are still
there in the science museum of the Calcutta University. Thus writes contributor
Dipak Basu, referencing the Proceedings of the IEEE, January, 1998.



Bose repeated his demonstration
in the Royal Society in London in 1899 in the presence of Lord Rayleigh
(Nobel prize winner in Physics, 1904), Fleming (Professor at London university
and later an advisor to the Marconi company), and Lord Lister (President
of the Royal Society). As a result he was offered Professorship in Cambridge,
but declined.



Bose had solved the problem
of the Hertz not being able to penetrate walls, mountains or water. Marconi
was present in the meeting of the Royal Society and it is thought that
he stole the notetbook of Bose that included the drawing of the 'Mercuri
Coherer with a telephone detector'. Marconi's Coherer, which he used in
1901, was the exact copy of that of Bose. Apparently Marcon was unable
to explain how he got to the design. He said that an Italian Navy engineer
called Solari had developed it, but Solari late denied it. Marconi then
said that Italian Professor Timasina did, which later was exposed as a
lie by another Italian professor, Banti.



Bose did not apply for a patent
on his design because he believed in the free flow of inventions in science.
But under pressure from American friends, he applied for the patent in
September 1901. He was awarded the US patent for the invention of the
radio in 1904. By that time Marconi had received his patent and international
recognition.



"Hello Rainey!"
It is reputed that
Nathan B. Stubblefield, a farmer from Murray,
Kentucky, made a voice transmission four years before Marconi transmitted
radio signals. in 1892, Stubblefield handed his friend Rainey T. Wells
a box and told him to walk away some distance. Wells said later: "I had
hardly reached my post.. when I heard I heard HELLO RAINEY come booming
out of the receiver."



Stubblefield
demonstrated his invention to the press in 1902 but, being afraid that
his invention will be stolen, never marketed his wireless radio. When
he was found dead in 1929, his radio equipment was gone. Nikoli Tesla
remains to be acknowledged as the inventor of the radio.



Radio everywhere
Today, there are more than 33,000 radio stations around the world, with
more than 12,000 in the US alone. Worldwide there are 2,24 billion radio
sets, or one radio for every 2.5 persons; proof that video never killed
the radio star.






In 1894 the president of the Royal Society, Lord Kelvin, prophesied that
radio had no future. The first radio factory was opened by Marconi 5 years
later.



Marconi invented the radio direction finder, a radio signal
device used by planes and ships to fix their positions. He also invented
the automatic alarm which picks up distress signals and sounds an alarm.
He also introduced the use of ultrahigh-frequency (UHF) waves for radio
communication. Marconi died in Rome in 1937 while in charge of scientific
research for Mussolini's government.



After the invention of the transistor by Bell Labs scientists
in 1947, several US electronics companies rejected the idea of a portable
radio. They apparently said: "Who would want to carry a radio around with
them?" At the time, radio sets were rather large. When Bell Labs put the
transistor on the market in 1952 they had few takers apart from a small
Japanese start-up called Sony. Sony introduced the transistor radio in
1954.



The phonograph was invented by Thomas Edison in 1877, the
long-playing record by Paul Goldmark in 1948, and the CD by Philips in
1980. The LP is not dead yet: more than 20 million were sold in 1997.
In the same period, more than 1,4 billion cassettes were sold, and about
2,2 billion CDs. Not counting pirated copies! One in three CDs sold globally
is manufactured illegally, with the worst culprits residing in China,
Russia and Mexico.
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