తంతి: కూర్పుల మధ్య తేడాలు

[[Albert Turpain]] sent and received his first radio signal, using Morse code, in [[France]], up to 25 meters in 1895.<ref name="dspt">{{cite web |url=http://dspt.club.fr/TURPAIN.htm|title=Raconte-moi la radio: Albert TURPAIN|accessdate=2009-05-07|work=Pierre Dessapt}}</ref>

[[File:Post Office Engineers.jpg|thumb|Post Office Engineers inspect [[Marconi Company|Marconi]]'s equipment on Flat Holm, May 1897]]

[[Guglielmo Marconi]] sent and received his first radio [[Wiktionary:signal|signal]] in [[Italy]] up to 6 kilometres in 1896. On 13 May 1897, Marconi, assisted by George Kemp, a [[Cardiff]] Post Office engineer, transmitted the first [[wireless]] signals over water to [[Lavernock]] (near [[Penarth]] in [[Wales]]) from [[Flat Holm]].<ref>{{cite web |url=http://www.bbc.co.uk/wales/southeast/sites/flatholm/pages/marconi.shtml |title=Marconi: Radio Pioneer |accessdate=2008-04-12 |work=BBC South East Wales }}</ref> Having failed to interest the [[Italy|Italian]] government, the 22-year-old inventor brought his telegraphy system to Britain and met [[William Preece]], a Welshman, who was a major figure in the field and Chief Engineer of the [[General Post Office]]. A pair of masts about {{convert|34|m|ft|0}} high were erected, at Lavernock Point and on Flat Holm. The receiving mast at Lavernock Point was a {{convert|30|m|ft|0|adj=on}} high pole topped with a cylindrical cap of zinc connected to a detector with insulated copper wire. At Flat Holm the sending equipment included a [[Ruhmkorff coil]] with an eight-cell battery. The first trial on 11 and 12 May failed but on the 13th the mast at Lavernock was extended to {{convert|50|m|ft|0}} and the signals, in Morse code, were received clearly. The message sent was "ARE YOU READY"; the Morse slip signed by Marconi and Kemp is now in the [[National Museum of Wales]].

In 1898 Popov accomplished successful experiments of wireless communication between a naval base and a [[Pre-dreadnought|battleship]].

In 1900 the crew of the Russian coast defense ship ''General-Admiral Graf Apraksin'' as well as stranded Finnish fishermen were saved in the [[Gulf of Finland]] because of exchange of distress telegrams between two radiostations, located at [[Suursaari|Hogland island]] and inside a Russian [[naval base]] in [[Kotka]]. Both stations of wireless telegraphy were built under Popov's instructions.

In 1901, Marconi radiotelegraphed the letter "S" across the [[Atlantic Ocean]] from his station in [[Poldhu|Poldhu, Cornwall]] to [[Signal Hill, Newfoundland and Labrador|St. John's, Newfoundland]].

Radiotelegraphy proved effective for rescue work in sea [[disaster]]s by enabling effective communication between ships and from ship to shore.

==యివి కూడా చూడండి==