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The first commercial AM Audion vacuum tube radio transmitter, built in 1914 by Lee De Forest who invented the Audion in 1906. During the mid-1920s, amplifying vacuum tubes revolutionized radio receivers and transmitters. John Ambrose Fleming developed a vacuum tube diode. Lee de Forest placed a screen, added a "grid" electrode, creating the triode.
There, Wavering and Lear together developed the first commercially successful car radio calling it the Motorola. [4] [5] Wavering and Galvin traveled around the country selling radios and teaching new dealers how to install them. [7] In 1932, Paul Galvin selected Wavering to lead Motorola's car radio and police two-way communications businesses.
In the late 1980s or early 1990s, [10] [11] [12] Baylis saw a television programme about the spread of AIDS in Africa and realised that a way to halt the spread of the disease would be to educate and disseminate information by radio. [11] [13] Within 30 minutes, he had assembled the first prototype of his most well-known invention, the wind-up ...
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.
1922: J. McWilliams Stone invents the first portable radio receiver. George Frost builds the first "car radio" in his Ford Model T. 1923 The 15-year-old Manfred von Ardenne is granted his first patent for an electron tube having a plurality of electrodes. Siegmund Loewe (1885–1962) builds with the tube his first radio receiver "Loewe Opta-".
Thirty-five years ago, users heard the infamous dial-up sound for the first time. The '80s were a decade defined by major technological innovations, big hair, cult-classic movies and the start of ...
In 1983, KDAY-AM became the first radio station to play wall-to-wall rap music, thanks to an ambitious new music director and some soon-to-be famous DJs. When L.A. invented rap radio: The rise of KDAY
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.