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The invention of radio communication was preceded by many decades of establishing theoretical underpinnings, ... First Thirty Years of Radio, 1895–1925.
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.
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.
Armstrong's "feed back" circuit drawing, from Radio Broadcast vol. 1 no. 1 1922. Armstrong began working on his first major invention while still an undergraduate at Columbia. In late 1906, Lee de Forest had invented the three-element (triode) "grid Audion" vacuum-tube. How vacuum tubes worked was not understood at the time.
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.
Internet radio: although the Internet originally was used for only text and graphics, beginning in the early 1990s it was adapted to transmitting audio; improved dial-up modems and audio compression in the 1990s allowed Internet radio to be accessed by the average user years before video content, which generally requires a broadband connection.
A family listening to a crystal radio in the 1920s Greenleaf Whittier Pickard's US Patent 836,531 "Means for receiving intelligence communicated by electric waves" diagram US Bureau of Standards 1922 Circular 120 "A simple homemade radio receiving outfit" taught Americans how to build a crystal radio. [25] Crystal radio was invented by a long ...
Reginald Aubrey Fessenden (October 6, 1866 – July 22, 1932) was a Canadian electrical engineer and inventor who received hundreds of patents in fields related to radio and sonar between 1891 and 1936 (seven of them after his death).