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The early history of radio is the history of technology that produces and uses radio instruments that use radio waves. Within the timeline of radio, many people contributed theory and inventions in what became radio. Radio development began as "wireless telegraphy". Later radio history increasingly involves matters of broadcasting.
Before the discovery of electromagnetic waves and the development of radio communication, there were many wireless telegraph systems proposed and tested. [4] In April 1872 William Henry Ward received U.S. patent 126,356 for a wireless telegraphy system where he theorized that convection currents in the atmosphere could carry signals like a telegraph wire. [5]
Cooper is the lead inventor named on "radio telephone system" filed on October 17, 1973, with the U.S. Patent Office and later issued as U.S. Patent 3,906,166. [20] John Francis Mitchell , Motorola's Chief of Portable Communication Products (and Cooper's Manager and Mentor) and the engineers who worked for Cooper and Mitchell are also named on ...
1920s: Radio was first used to transmit pictures visible as television. 1926: Official Egyptian decree to regulate radio transmission stations and radio receivers. [40] Early 1930s: Single sideband (SSB) and frequency modulation (FM) were invented by amateur radio operators. By 1940, they were established commercial modes.
Edwin Howard Armstrong (December 18, 1890 [2] – February 1, 1954 [3]) was an American electrical engineer and inventor who developed FM (frequency modulation) radio and the superheterodyne receiver system.
Radio broadcasting has been used in the United States since the early 1920s to distribute news and entertainment to a national audience. In 1923, 1 percent of U.S. households owned at least one radio receiver, while a majority did by 1931 and 75 percent did by 1937.
In 1945 on the 50th anniversary of Popov's experiment the old Soviet Union made 7 May a new holiday, Radio Day, the day they claim Popov invented radio. Historians note this holiday may be more due to Cold War era politics than historical evidence. [14] [1] [3] Radio Day is still officially marked in Russia and Bulgaria.
Guglielmo Giovanni Maria Marconi [11] [12] was born in Palazzo Marescalchi in Bologna on 25 April 1874, the second son of Giuseppe Marconi (an Italian aristocratic landowner from Porretta Terme who lived in the countryside of Pontecchio) and his Irish wife Annie Jameson (daughter of Andrew Jameson of Daphne Castle in County Wexford, sister of Scottish naturalist James Sligo Jameson, and ...