Radiodiffusion
Radiodiffusion (etiam note simplmente como radio, ab latino radius "barra del rota, radio de lumine") esse le transmission de signales de modulation de undas electromagnetic con frequentias sub illos del lumine visibile.   Radio o radiotelegraphia esseva nominate al initio "telegraphia sin filo".  Le radiation electromagnetic propoga per campos electromagnetic que pote transversar le aere e le vacuo spatial.  Information pote esser transmittite per modular systematicamente alcun characteristica del undas radiate:  pro exemplo, amplitude, frequentia, phase, o grandor del pulso.  Quando undas radio pasa un conductor electric, le campos undulante induce un currente electric in le conductor.  Le processo de demodulation esse le detection e le transformation del radios a sono o altere signalos.

Stationes radio usa le propagation de undas radio pro transmitter programmas sonic; iste radios usualmente usa modulation de amplitude o modulation de frequentia.  Le parola radiodiffusion esse le nomine del transmission.  Television etiam usa undas radio pro transmitter le video e le sono de un programma.

Invention

In 1893, in St. Louis, Missouri, Nikola Tesla fabricava dispositivos pro su experimentos con electricitate.  Ille initialmente ha experimentate con receptores magnetic, non como coheritores (dispositivos de detection consistente de tubos con ferro que esseva inventate per Temistocle Calzecchi-Onesti de Fermo in Italia in 1884) usate per Guglielmo Marconi e altere precedente experimentatores.

In 1895 Alexander Stepanovič Popov ha construite su prime receptor de radio, que contineva un coheritor.

Commercialisation
In 1896, Marconi esseva premiate con le patente britannic 12039, Improvements in transmitting electrical impulses and signals and in apparatus there-for, pro le radio. In 1897, il ha stabilite un station radio in le insula Isle of Wight, Anglaterra. 

Marconi esseva creditate con le invention del radio, ma in 1943, pro motivos politic connexe al processo del Statos Unite de America contra Marconi super infraction a patentes durante le Prime Guerra Mundial, le Corte Supreme del SUA decideva que le patente de radio numero 645.576 de Tesla es le prime.

Usages 
Le prime usage commercial esseva maritime, usate pro mandar messages cifrate in codice Morse inter naves, e inter naves e terra.  Alcun usages notabile ante su adoption large include su usage per le Flotta Japanese contra le flotta Russe in le Battalia de Tsushima in 1905, e le communication inter le RMS Titanic e le litore durante de su affundation in 1912.

Su adoption general initiava con le Prime Guerra Mundial; Germania usava radio pro su messages diplomatic quando il esseva discoperite que Britannia ha ascoltate su cablos subaquatic.  Le Decequatre Punctos del Statos Unite de America esseva transmittite a Germania per radio.

Le prime transmissor private esseva in San Jose, California in 1909, e esseva facibile in le annos 1920 con le introduction large del receptores de radio in Europa e le SUA.  Le transmission de puncto a puncto esseva usate pro le transmission de messages telephonic in iste decennio.  In iste decennio etiam esseva inventate radar, le usage de undas radio pro locar e identificar cosas como naves e aviones.

Bibliographia
 Aitkin Hugh G. J. The Continuous Wave: Technology and the American Radio, 1900-1932 (Princeton University Press, 1985).
 Briggs Asa. The History of Broadcasting in the United Kingdom (Oxford University Press, 1961).
 De Forest, Lee. Father of Radio: The Autobiography of Lee de Forest (1950).
 Ewbank Henry and Lawton Sherman P. Broadcasting: Radio and Television (Harper & Brothers, 1952).
 Fisher, Marc Something In The Air: Radio, Rock, and the Revolution That Shaped A Generation (Random House, 2007).
 Leland I. Anderson (ed.), "John Stone Stone, Nikola Tesla's Priority in Radio and Continuous-Wave Radiofrequency Apparatus". The Antique Wireless Review, Vol. 1. 1986. 24 pages, illustrated.
 Lewis, Tom, Empire of the Air: The Men Who Made Radio, 1st ed., New York : E. Burlingame Books, 1991. ISBN 0-06-018215-6. "Empire of the Air: The Men Who Made Radio" (1992) by Ken Burns was a PBS documentary based on the book.
 Maclaurin W. Rupert. Invention and Innovation in the Radio Industry (The Macmillan Company, 1949).
 Ray William B. FCC: The Ups and Downs of Radio-TV Regulation (Iowa State University Press, 1990).
 Russo, Alexan der. Points on the Dial: Golden Age Radio Beyond the Networks (Duke University Press; 2010) 278 pages; discusses regional and local radio as forms that "complicate" the image of the medium as a national unifier from the 1920s to the 1950s.
 Scannell, Paddy, and Cardiff, David. A Social History of British Broadcasting, Volume One, 1922-1939 (Basil Blackwell, 1991).
 Schwoch James. The American Radio Industry and Its Latin American Activities, 1900-1939 (University of Illinois Press, 1990).
 Sterling Christopher H. Electronic Media, A Guide to Trends in Broadcasting and Newer Technologies 1920-1983 (Praeger, 1984).
 White Llewellyn. The American Radio (University of Chicago Press, 1947).
 Ulrich L. Rohde, Jerry Whitaker "Communications Receivers, Third Edition ", McGraw Hill, New York, NY, 2001, ISBN 0-07-136121-9.

Ligamines externe 
General
  Rubin, Richard.  It's Radi-O! The Atlantic Monthly; januario 1998.

Historia
  U.S. Supreme Court, "Marconi Wireless Telegraph co. of America v. United States". 320 U.S. 1. Nos. 369, 373. Arguite 9-12 de april, 1943. Decidite 21 de junio 1943.
  Horzepa, Stan, "Surfin': Who Invented Radio?" Arrl.org. 10 October 2003.
  Steven Schoenherr's History of Radio 
  The Broadcast Archive - Radio History on the Web!
  Canadian Communications Foundation - The History on Canadian Broadcasting.
  United States Early Radio History
  Historic Radios from Around the World at Kurrajong Radio Museum, Australia
  Early Canadian Radio Station Lists
  United States Early Radio History

Antiquitates
  George H. Clark Radioana Collection, ca. 1880 - 1950 - Archives Center, National Museum of American History, Smithsonian Institution
  A gallery of Antiques from the 1920s to the 1960s

Technic
  Radio Frequency Chart  commandline.net.
  Interactive Explanation of Radio Receiver Construction 
  How Stuff Works - Radio
  VOR Basic Information 
  Dr. Phil's Receiver Designs Single-Triode and Single-Transistor Regenerative Radio Designs

Bibliographia 
  [http://pagina.vizzavi.pt/~nc22723a/radio.htm  A História da Rádio em Datas (1819-1997) - notas re su etymologia
 Leigh White, Buck Fuller and the Dymaxion World (refere a Waldo Warren como inventor del parola radio), in: The Saturday Evening Post, 14 October 1944; citate in: Joachim Krausse e Claude Lichtenstein (eds.), Your Private Sky, Lars Müller Publishers, Baden/Switzerland, 1999, pagina 132. ISBN 3-907044-88-6
 L. de Forest, articulo in Electrical World 22 junio 1270/1 (1907), uso precoce del parola "radio".
 http://web.mit.edu/varun_ag/www/bose.html  - Isto contine un prova que Sir Jagadish Chandra Bose inventava le coheritor de mercurio que esseva usate plus tarde per Guglielmo Marconi e insimul con altere patentes.
 

Radio
Sono