Editing Radio broadcasting (section)

==History==
{{see also|History of radio#Broadcasting|History of broadcasting}}

[[File:Soireé-Musicale.jpg|thumb|350px|Advertisement placed on November 5, 1919 in the ''Nieuwe Rotterdamsche Courant'', announcing PCGG's debut broadcast scheduled for the next evening.<ref name="philips">[https://www.vintageradio.nl/Menu/philips_engels.htm "Vintage Radio Web: Philips"] {{Webarchive|url=https://web.archive.org/web/20200207125459/https://www.vintageradio.nl/Menu/philips_engels.htm |date=February 7, 2020 }} (vintageradio.nl)</ref>]]
The earliest [[radio]] stations were [[radiotelegraphy]] systems and did not carry audio. For audio broadcasts to be possible, electronic detection and amplification devices had to be incorporated.

The [[thermionic valve]], a kind of [[vacuum tube]], was invented in 1904 by the English physicist [[John Ambrose Fleming]]. He developed a device that he called an "oscillation valve," because it passes current in only one direction. The heated filament, or [[cathode]], was capable of [[thermionic emission]] of electrons that would flow to the ''[[Plate electrode|plate]]'' (or ''[[anode]]'') when it was at a higher voltage. Electrons, however, could not pass in the reverse direction because the plate was not heated, and thus not capable of thermionic emission of electrons. Later known as the [[Fleming valve]], it could be used as a [[rectifier]] of alternating current, and as a radio wave [[Detector (radio)|detector]].<ref>{{Cite journal|last=Guarnieri|first=M.|year=2012|title=The age of vacuum tubes: Early devices and the rise of radio communications|journal=IEEE Ind. Electron. M.|pages=41–43|doi=10.1109/MIE.2012.2182822|s2cid=23351454}}</ref> This greatly improved the [[crystal set]], which rectified the radio signal using an early solid-state diode based on a crystal and a so-called [[cat's whisker]]. However, an amplifier was still required.

The [[triode]] (mercury-vapor filled with a control grid) was created on March 4, 1906, by the Austrian [[Robert von Lieben]];<ref>{{cite web | last=Schmidt | first=Hans-Thomas | title=Die Liebenröhre | website=Umleitung zur Homepage von H.-T. Schmidt | url=http://www.hts-homepage.de/Lieben/Lieben.html | language=de | access-date=August 10, 2019}} DRP 179807</ref><ref>[[Tapan Kumar Sarkar|Tapan K. Sarkar]] (ed.) "History of wireless", John Wiley and Sons, 2006. {{ISBN|0-471-71814-9}}, p.335</ref><ref>Sōgo Okamura (ed), ''[https://books.google.com/books?id=VHFyngmO95YC&pg=PA20 History of Electron Tubes]'', IOS Press, 1994, {{ISBN|90-5199-145-2}}, page 20.</ref> independently, on October 25, 1906,<ref>{{cite web | title=US841387A - Device for amplifying feeble electrical currents. | website=Google Patents | date=October 25, 1906 | url=https://patents.google.com/patent/US841387A | access-date=August 10, 2019}}</ref><ref>{{cite web | title=US879532A - Space telegraphy. | website=Google Patents | date=January 29, 1907 | url=https://patents.google.com/patent/US879532A | access-date=August 10, 2019}}</ref> [[Lee De Forest]] patented his three-element [[Audion tube|Audion]]. It{{which|date=July 2024}} was not put to practical use until 1912 when its amplifying ability became recognized by researchers.<ref>{{cite book|last=Nebeker|first=Frederik|title=Dawn of the Electronic Age: Electrical Technologies in the Shaping of the Modern World, 1914 to 1945|publisher=John Wiley & Sons|year=2009|pages=14–15|url=https://books.google.com/books?id=xwmH6-q5O5AC&pg=PA14|isbn=978-0470409749}}</ref>
[[File:Control room and radio studio in Fabianinkatu headquarters of Yleisradio, ca 1938.jpg|thumb|Control room and radio studio of the [[Finland|Finnish]] broadcasting company [[Yle|Yleisradio]] (YLE) in the 1930s.]]
By about 1920, valve technology had matured to the point where radio broadcasting was quickly becoming viable.<ref>{{Cite web|url=http://www.makingthemodernworld.org.uk/stories/the_age_of_the_mass/07.ST.04/?scene=4|archive-url=http://webarchive.nationalarchives.gov.uk/20170405144750/http://www.makingthemodernworld.org.uk/stories/the_age_of_the_mass/07.ST.04/?scene=4|url-status=dead|archive-date=April 5, 2017|title= Mass consumption - The invention of radio |website=Making the Modern World |access-date=October 4, 2013}}</ref><ref>{{Cite journal|last=Guarnieri|first=M.|year=2012|title=The age of vacuum tubes: the conquest of analog communications|journal=IEEE Ind. Electron. M.|pages=52–54|doi=10.1109/MIE.2012.2193274|s2cid=42357863}}</ref> However, an early audio transmission that could be termed a ''broadcast'' may have occurred on [[Christmas Eve]] in 1906 by [[Reginald Fessenden]], although this is disputed.<ref>{{cite web |last1=O'Neal |first1=James |title=Fessenden — The Next Chapter |url=https://www.radioworld.com/columns-and-views/fessenden-the-next-chapter |website=Radio World |access-date=May 17, 2022 |date=December 23, 2008}}</ref> While many early experimenters attempted to create systems similar to [[radiotelephone]] devices by which only two parties were meant to communicate, there were others who intended to transmit to larger audiences. [[Charles Herrold]] started broadcasting in [[California]] in 1909 and was carrying audio by the next year. (Herrold's station eventually became [[KCBS (AM)|KCBS]]).<ref>{{Cite web |title=KQW KCBS History |url=http://www.theradiohistorian.org/kqw.htm |access-date=2025-03-25 |website=www.theradiohistorian.org}}</ref>

In The Hague, the Netherlands, [[PCGG]] started broadcasting on November 6, 1919, making it arguably the first commercial broadcasting station. In 1916, [[Frank Conrad]], an electrical engineer employed at the [[Westinghouse Electric (1886)|Westinghouse Electric Corporation]], began broadcasting from his [[Wilkinsburg, Pennsylvania]] garage with the call letters 8XK. Later, the station was moved to the top of the Westinghouse factory building in [[East Pittsburgh, Pennsylvania]]. Westinghouse relaunched the station as [[KDKA (AM)|KDKA]] on November 2, 1920, as the first commercially licensed radio station in the United States.<ref>{{cite journal|last= Baudino|first=Joseph E|author2=John M. Kittross |title=Broadcasting's Oldest Stations: An Examination of Four Claimants|journal=Journal of Broadcasting|pages=61–82|date=Winter 1977|volume=21|doi=10.1080/08838157709363817|url=https://www.tandfonline.com/doi/abs/10.1080/08838157709363817|archive-url=https://web.archive.org/web/20080306145733/http://www.ieee.org/web/aboutus/history_center/kdka.html|archive-date=March 6, 2008|access-date=January 18, 2013|url-access=subscription}}</ref> The [[commercial broadcasting]] designation came from the type of [[broadcast license]]; [[advertising|advertisement]]s did not air until years later. The first licensed broadcast in the United States came from KDKA itself: the results of the [[U.S. presidential election, 1920|Harding/Cox Presidential Election]]. The [[Montreal]] station that became [[CFCF-AM|CFCF]] began [[broadcast programming]] on May 20, 1920, and the [[Detroit]] station that became [[WWJ (AM)|WWJ]] began program broadcasts beginning on August 20, 1920, although neither held a license at the time.

In 1920, wireless broadcasts for entertainment began in the UK from the [[Marconi Research Centre]] [[2MT]] at [[Writtle]] near [[Chelmsford, England]]. A famous broadcast from Marconi's New Street Works factory in Chelmsford was made by the famous [[soprano]] Dame [[Nellie Melba]] on June 15, 1920, where she sang two arias and her famous trill. She was the first artist of international renown to participate in direct radio broadcasts. The [[2MT]] station began to broadcast regular entertainment in 1922. The [[BBC]] was amalgamated in 1922 and received a [[Royal Charter]] in 1926, making it the first national broadcaster in the world,<ref>{{Cite web|url=http://www.g0mwt.org.uk/new-street/|title=CARS - Marconi Hall Street, New Street and 2MT callsign|website=www.g0mwt.org.uk}}</ref><ref>{{cite news |title=BBC History – The BBC takes to the Airwaves|url=http://news.bbc.co.uk/aboutbbcnews/spl/hi/history/html/default.stm|work=BBC News}}</ref> followed by [[Czech Radio|Czechoslovak Radio]] and other European broadcasters in 1923.

Radio Argentina began regularly scheduled transmissions from the [[Teatro Coliseo]] in [[Buenos Aires]] on August 27, 1920, making its own priority claim. The station got its license on November 19, 1923. The delay was due to the lack of official Argentine licensing procedures before that date. This station continued regular broadcasting of entertainment, and cultural fare for several decades.<ref>Atgelt, Carlos A. [http://www.oldradio.com/archives/international/argentin.html "Early History of Radio Broadcasting in Argentina."] {{Webarchive|url=https://web.archive.org/web/20210424214128/https://www.oldradio.com/archives/international/argentin.html |date=April 24, 2021 }} The Broadcast Archive (Oldradio.com).</ref>

Radio in education soon followed, and colleges across the U.S. began adding radio broadcasting courses to their curricula. Curry College in Milton, Massachusetts introduced one of the first broadcasting majors in 1932 when the college teamed up with WLOE in Boston to have students broadcast programs.<ref>{{cite web|url=http://www.curry.edu|title=Curry College - Home|website=www.curry.edu|access-date=July 13, 2018}}</ref> By 1931, a majority of U.S. households owned at least one [[radio receiver]].<ref>{{cite journal|last=Craig|first=Steve|year=2004|title=How America Adopted Radio: Demographic Differences in Set Ownership Reported in the 1930–1950 U.S. Censuses|journal=[[Journal of Broadcasting & Electronic Media]]|volume=48|issue=2|pages=179–195|publisher=[[Routledge]]|doi=10.1207/s15506878jobem4802_2|s2cid=145186571|url=https://www.researchgate.net/publication/233149747}}</ref>

[[File:Radio Libertaire 3.jpg|thumb|Use of a sound broadcasting station]]
In line to [[ITU Radio Regulations]] (article1.61) each ''broadcasting station'' shall be classified by the service in which it operates permanently or temporarily.