Search results
Results from the WOW.Com Content Network
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]
Broadcast radio in the United States underwent a period of rapid change through the decade of the 1920s. Technology advances, better regulation, rapid consumer adoption, and the creation of broadcast networks transformed radio from a consumer curiosity into the mass media powerhouse that defined the Golden Age of Radio.
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.
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 ...
The first practical radio transmitters and receivers invented in 1894–1895 by Guglielmo Marconi used radiotelegraphy. [5] It continued to be the only type of radio transmission during the first few decades of radio, called the "wireless telegraphy era" up until World War I , when the development of amplitude modulation (AM) radiotelephony ...
"The influence of the movies and radio and magazines created desire for mass production commodities that were copies of what local residents had seen." ... 1920s: Transportation. Though invented ...
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.