Search results
Results from the WOW.Com Content Network
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.
The next year the company used the same concept to begin establishing the first radio network. [107] The WEAF and WJZ chains. At the same time in early 1922 that it announced the beginning of advertisement-supported broadcasting, AT&T also introduced its plans for the development of the first radio network. [104]
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.
The radio is a portable superheterodyne that Armstrong built as a present for her. In 1923, combining his love for high places with courtship rituals, Armstrong climbed the WJZ (now WABC) antenna located atop a 20-story building in New York City, where he reportedly did a handstand, and when a witness asked him what motivated him to "do these ...
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-".
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.
November 20, 1985 — Microsoft releases the first version of Windows The original Windows 1 was released in November 1985. Microsoft founder Bill Gates spearheaded the development, which was ...
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]