View source for History of radio

{{Short description|none}}
{{About||the controversy about who invented radio|Invention of radio}}
{{pp|small=yes}}

[[File:Albert Einstein with engineers and scientists - RCA radio station - Hagley Archives - restoration1.jpg|thumb|right|upright=1.4|Early pioneers of radio science and technology in the United States including [[Charles Steinmetz]], [[David Sarnoff]], [[Irving Langmuir]] and [[Alfred Norton Goldsmith|Alfred Goldsmith]] in 1921, photographed next to the antenna feed wires of the [[New Brunswick Marconi Station]], one of the first transatlantic radio links. Photo includes [[Albert Einstein]] as a visiting guest.]]

The early '''history of radio''' is the [[history of technology]] that produces and uses [[radio equipment|radio instruments]] that use [[radio wave]]s.  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]].

== Discovery ==
{{See also|Invention of radio}}

[[File:Heinrich Rudolf Hertz.jpg|thumb|Heinrich Rudolf Hertz (1856–1894) proved the existence of electromagnetic radiation.]]

In an 1864 presentation, published in 1865, [[James Clerk Maxwell]] proposed theories of [[electromagnetism]] and mathematical proofs demonstrating that light, radio and x-rays were all types of electromagnetic waves propagating through [[free space]].<ref name="sparkmuseum.com">{{cite web|url=http://www.sparkmuseum.com/BOOK_MAXWELL.HTM|title=James Clerk Maxwell (1831–1879)|work=(sparkmuseum.com)}}</ref><ref name="google.co.uk">{{cite book|url=https://books.google.com/books?id=5HVlBG_8nWIC&q=Maxwell+Predicts+Waves&pg=PA122|date=1992|title=Newton to Einstein: The Trail of Light|publisher=Cambridge University Press|author=Ralph Baierlein|access-date=3 February 2018|isbn=978-0521423236}}</ref><ref>G. R. M. Garratt, ''The Early History of Radio: From Faraday to Marconi'', IET – 1994, p. 27</ref><ref>{{cite web|url=https://courses.lumenlearning.com/boundless-physics/chapter/magnetic-fields-and-maxwell-revisited/|title=Magnetic Fields and Maxwell Revisited|work=lumenlearning.com}}</ref><ref>{{cite web|url=http://abyss.uoregon.edu/~js/glossary/electromagnetism.html|title=Electromagnetism (glossary)|work=uoregon.edu|access-date=2015-06-03|archive-date=2015-04-22|archive-url=https://web.archive.org/web/20150422001651/http://abyss.uoregon.edu/~js/glossary/electromagnetism.html|url-status=dead}}</ref>

Between 1886 and 1888 [[Heinrich Rudolf Hertz]] published the results of experiments wherein he was able to transmit electromagnetic waves (radio waves) through the air, proving Maxwell's electromagnetic theory.<ref>Peter Rowlands, ''Oliver Lodge and the Liverpool Physical Society'', Liverpool University Press, 1990, p. 24</ref><ref name="Heinrich 1893">[https://archive.org/details/electricwavesbe00jonegoog/page/n35 <!-- pg=1 -->  ''Electric waves; being research on the propagation of electric action with finite velocity through space''] by Heinrich Rudolph Hertz (English translation by Daniel Evan Jones), Macmillan and Co., 1893, pp. 1–5</ref>

==Exploration of optical qualities==

[[File:Refraction of Hertzian waves by a paraffin lens 1897.png|thumb|left| Early experiment demonstrating refraction of microwaves by a paraffin lens by [[John Ambrose Fleming]] in 1897]]

After their discovery many scientists and inventors experimented with transmitting and detecting "Hertzian waves" (it would take almost 20 years for the term "radio" to be universally adopted for this type of electromagnetic radiation).<ref>{{cite web|url=https://earlyradiohistory.us/sec022.htm|title=Section 22: Word Origins|work=earlyradiohistory.us}}</ref> Maxwell's theory showing that light and Hertzian electromagnetic waves were the same phenomenon at different wavelengths led "Maxwellian" scientists such as John Perry, [[Frederick Thomas Trouton]] and Alexander Trotter to assume they would be analogous to optical light.<ref>W. Bernard Carlson, ''Tesla: Inventor of the Electrical Age'', 2013, pp. 125–126</ref><ref>Sungook Hong, ''Wireless: From Marconi's Black-box to the Audion'', MIT Press, 2001, p. 2</ref>

Following Hertz' untimely death in 1894, British physicist and writer [[Oliver Lodge]] presented a widely covered lecture on Hertzian waves at the [[Royal Institution]] on June 1 of the same year.<ref>{{Cite web|url=https://ethw.org/Thread:Milestone-Proposal_talk:First_generation_and_experimental_proof_of_electromagnetic_waves_1886-1888./Hertz_milestone_proposal/reply_(6)|title=Thread:Milestone-Proposal talk:First generation and experimental proof of electromagnetic waves 1886–1888./Hertz milestone proposal/reply (6)|date=December 11, 2018|website=ETHW|access-date=December 15, 2022|archive-date=December 13, 2022|archive-url=https://web.archive.org/web/20221213124752/https://ethw.org/Thread:Milestone-Proposal_talk:First_generation_and_experimental_proof_of_electromagnetic_waves_1886-1888./Hertz_milestone_proposal/reply_(6)|url-status=dead}}</ref> Lodge focused on the optical qualities of the waves and demonstrated how to transmit and detect them (using an improved variation of French physicist [[Édouard Branly]]'s detector Lodge named the "[[coherer]]").<ref>Hugh G.J. Aitken, ''Syntony and Spark – The Origins of Radio'', Princeton University Press – 2014, p. 103</ref> Lodge further expanded on Hertz' experiments showing how these new waves exhibited like light [[refraction]], [[diffraction]], [[polarization (waves)|polarization]], [[interference (wave motion)|interference]] and [[standing wave]]s,<ref name="Sarkar1" /> confirming that Hertz' waves and light waves were both forms of Maxwell's [[electromagnetic wave]]s. During part of the demonstration the waves were sent from the neighboring [[Clarendon Laboratory]] building, and received by apparatus in the lecture theater.<ref name="antiquewireless.org">James P. Rybak, [http://www.antiquewireless.org/uploads/1/6/1/2/16129770/48-oliver_lodge.pdf Oliver Lodge: Almost the Father of Radio] {{Webarchive|url=https://web.archive.org/web/20181003074015/http://www.antiquewireless.org/uploads/1/6/1/2/16129770/48-oliver_lodge.pdf |date=2018-10-03 }}, pp. 5–6, from Antique Wireless</ref>

[[File:PSM V83 D416 Oliver Joseph Lodge.png|thumb|Oliver Lodge's 1894 lectures on Hertz demonstrated how to transmit and detect radio waves.]]

After Lodge's demonstrations researchers pushed their experiments further down the electromagnetic spectrum towards visible light to further explore the [[Quasioptics|quasioptical]] nature at these wavelengths.<ref>Jagadis Chandra Bose, Prantosh Bhattacharyya, Meher H., J.C. ''Bose and Microwaves: A Collection'', Bose Institute – 1995, p. 2</ref> [[Oliver Lodge]] and [[Augusto Righi]] experimented with 1.5 and 12&nbsp;GHz microwaves respectively, generated by small metal ball spark resonators.<ref name="Sarkar1">{{cite book
 | last1  = Sarkar
 | first1 = T. K.
 | last2  = Mailloux
 | first2 = Robert
 | last3  = Oliner
 | first3 = Arthur A.
 | title  = History of Wireless
 | publisher = John Wiley and Sons
 | date   = 2006
 | pages  = 474–86
 | url    = https://archive.org/stream/HistoryOfWireless#page/n496/mode/2up
 | isbn   = 978-0471783015
 | author-link1=Tapan Sarkar
 | author-link3=Arthur A. Oliner
 }}</ref>  Russian physicist [[Pyotr Lebedev]] in 1895 conducted experiments in the 50&nbsp;GHz (6 millimeter) range.<ref name="Sarkar1" /> Bengali Indian physicist [[Jagadish Chandra Bose]] conducted experiments at wavelengths of 60&nbsp;GHz (5 millimeter) and invented [[waveguide (electromagnetism)|waveguide]]s, [[horn antenna]]s, and [[semiconductor]] [[crystal detector]]s for use in his experiments.<ref>Visvapriya Mukherji, Jagadis Chandra Bose, Publications Division, Ministry of Information and Broadcasting, Government of India · 1983, chapter 5 – Researches into Hertzian Waves</ref> He would later write an essay, "Adrisya Alok" ("Invisible Light") on how in November 1895 he conducted a public demonstration at the Town Hall of [[Kolkata]], [[India]] using millimeter-range-wavelength microwaves to trigger detectors that ignited gunpowder and rang a bell at a distance.<ref name="Mukherji, Visvapriya 1994">Mukherji, Visvapriya, ''Jagadish Chandra Bose, 2nd ed.'' 1994. Builders of Modern India series, Publications Division, Ministry of Information and Broadcasting, Government of India. {{ISBN|8123000472}}.</ref>

==Proposed applications==

Between 1890 and 1892 physicists such as John Perry, [[Frederick Thomas Trouton]] and [[William Crookes]] proposed electromagnetic or Hertzian waves as a navigation aid or means of communication, with Crookes writing on the possibilities of wireless [[telegraphy]] based on Hertzian waves in 1892.<ref name="Sungookp1to5">Hong (2001) pp. 5–10</ref> Among physicists, what were perceived as technical limitations to using these new waves, such as delicate equipment, the need for large amounts of power to transmit over limited ranges, and its similarity to already existent optical light transmitting devices, lead them to a belief that applications were very limited. The Serbian American engineer [[Nikola Tesla]] considered Hertzian waves relatively useless for long range transmission since "light" could not transmit further than [[Line-of-sight propagation|line of sight]].<ref>{{cite web|url=https://earlyradiohistory.us/tesla.htm|title=Nikola Tesla: The Guy Who DIDN'T 'Invent Radio'|date = 1 November 2012|author=Thomas H. White|work=earlyradiohistory.us}}</ref> There was speculation that this fog and stormy weather penetrating "invisible light" could be used in maritime applications such as lighthouses.<ref name="Sungookp1to5"/> The London journal ''The Electrician'' (December 1895) commented on Bose's achievements, saying "we may in time see the whole system of coast lighting throughout the navigable world revolutionized by an Indian Bengali scientist working single handed[ly] in our Presidency College Laboratory."<ref>{{Cite web|url=https://scroll.in/article/1027507/jagadish-chandra-bose-the-first-complete-biography-investigates-his-life-as-well-as-his-science|title=Jagadish Chandra Bose: The first complete biography investigates his life as well as his science|first=Kunal|last=Ghosh|date=July 4, 2022|website=Scroll.in}}</ref>

In 1895, adapting the techniques presented in Lodge's published lectures, Russian physicist [[Alexander Stepanovich Popov]] built a [[lightning detector]] that used a coherer based radio receiver.<ref>Christopher H. Sterling, ''Encyclopedia of Radio'', Routledge – 2003, p. 1820</ref> He presented it to the Russian Physical and Chemical Society on May 7, 1895.

==Marconi and radio telegraphy==

[[File:Post Office Engineers.jpg|thumb|British Post Office engineers inspect Guglielmo Marconi's wireless telegraphy (radio) equipment in 1897.]]

In 1894, the young Italian inventor [[Guglielmo Marconi]] began working on the idea of building long-distance wireless transmission systems based on the use of Hertzian waves (radio waves), a line of inquiry that he noted other inventors did not seem to be pursuing.<ref name="ABC-CLIO">{{cite book|title=Icons of Invention: the Makers of the Modern World from Gutenberg to Gates|author=John W. Klooster|publisher=ABC-CLIO|url=https://books.google.com/books?id=WKuG-VIwID8C&q=British+High+Court+upheld+patent+7777&pg=PA161|access-date=3 February 2018|isbn=978-0313347436|year=2009}}</ref>  Marconi read through the literature and used the ideas of others who were experimenting with radio waves but did a great deal to develop devices such as portable transmitters and receiver systems that could work over long distances,<ref name="ABC-CLIO"/> turning what was essentially a laboratory experiment into a useful communication system.<ref>Hong (2001) p. 22</ref> By August 1895, Marconi was field testing his system but even with improvements he was only able to transmit signals up to one-half mile, a distance Oliver Lodge had predicted in 1894 as the maximum transmission distance for radio waves. Marconi raised the height of his antenna and hit upon the idea of grounding his transmitter and receiver. With these improvements the system was capable of transmitting signals up to {{Convert|2|mi}} and over hills.<ref>Hong (2001) pp. 20–22</ref> This apparatus proved to be the first engineering-complete, commercially successful [[radio transmission]] system<ref name="SaturdayThompson">Correspondence to the editor of the Saturday Review, ''The Saturday Review of Politics, Literature, Science and Art'': [https://books.google.com/books?id=gHVHAAAAYAAJ&pg=PA556 "The Inventor of Wireless Telegraphy: A Reply"] from Guglielmo Marconi (3 May 1902, pp. 556–58) and [https://books.google.com/books?id=gHVHAAAAYAAJ&pg=PA598 "Wireless Telegraphy: A Rejoinder"] from Silvanus P. Thompson (10 May 1902, pp. 598–99)</ref><ref>{{cite web|url=http://www.radiomarconi.com/marconi/stravolgimento1.html|archive-url=https://web.archive.org/web/20010711202256/http://www.radiomarconi.com/marconi/stravolgimento1.html|url-status=usurped|archive-date=July 11, 2001|title=Marconi e lo Stravolgimento della Verità Storica Sulla Sua Opera|work=radiomarconi.com|author=Lodovico Gualandi}}</ref><ref>[https://books.google.com/books?id=-ZYZAQAAIAAJ&pg=PA294 "Wireless Telegraphy"] by G. Marconi (discussion), ''Proceedings of the Institution of Electrical Engineers'', (vol. 28, March 2, 1899), p. 294.</ref> and Marconi went on to file British patent GB189612039A, ''Improvements in transmitting electrical impulses and signals and in apparatus there-for'', in 1896. This patent was granted in the UK on 2 July 1897.<ref>https://worldwide.espacenet.com/patent/search/family/032189896/publication/GB189612039A?q=pn%3DGB189612039A{{Dead link|date=November 2024 |bot=InternetArchiveBot |fix-attempted=yes }}</ref>

===Nautical and transatlantic transmissions===
In 1897, Marconi established a radio station on the [[Isle of Wight]], England and opened his "wireless" factory in the former [[silk]]-works at Hall Street, [[Chelmsford]], England, in 1898, employing around 60 people.

On 12 December 1901, using a {{convert|500|ft|m|adj=on}} kite-supported antenna for reception—signals transmitted by the company's new high-power station at [[Poldhu]], Cornwall, Marconi transmitted a message across the Atlantic Ocean to [[Signal Hill (Newfoundland and Labrador)|Signal Hill]] in [[St. John's, Newfoundland and Labrador|St. John's]], [[Newfoundland and Labrador|Newfoundland]].<ref name=KIT>{{cite web|url=https://www.kit.edu/kit/english/pi_2011_8434.php|title=125 Years Discovery of Electromagnetic Waves|publisher=[[Karlsruhe Institute of Technology]]|language=en-US|url-status=live|date=May 16, 2022|accessdate=July 14, 2022|archivedate=July 14, 2022|archiveurl=https://web.archive.org/web/20220714163329/https://www.kit.edu/kit/english/pi_2011_8434.php}}</ref><ref name="ieeexplore.ieee.org">Bondyopadhyay, Prebir K.  (1995) "[https://ieeexplore.ieee.org/document/4137304/?tp=&arnumber=4137304 Guglielmo Marconi – The father of long distance radio communication – An engineer's tribute"], ''25th European Microwave Conference: Volume 2'', pp. 879–85</ref><ref name="1890s – 1930s: Radio">{{cite web|url=https://www.elon.edu/u/imagining/time-capsule/150-years/back-1890-1930/|title=1890s – 1930s: Radio|publisher=[[Elon University]]|language=en-US|url-status=live|accessdate=July 14, 2022|archivedate=June 8, 2022|archiveurl=https://web.archive.org/web/20220608035814/https://www.elon.edu/u/imagining/time-capsule/150-years/back-1890-1930/}}</ref><ref name="IEEEatlantic">{{Cite web |last=Belrose |first=John S. |date=5–7 September 1995 |title=Radio's First Message – Fessenden and Marconi |url=https://ewh.ieee.org/reg/7/millennium/radio/radio_differences.html |access-date=2022-11-06 |website=[[Institute of Electrical and Electronics Engineers]]}}</ref>

Marconi began to build high-powered stations on both sides of the Atlantic to communicate with ships at sea. In 1904, he established a commercial service to transmit nightly news summaries to subscribing ships, which could incorporate them into their on-board newspapers. A regular transatlantic radio-telegraph service was finally begun on 17 October 1907<ref>{{cite journal|title=The Clifden Station of the Marconi Wireless Telegraph System|journal=Scientific American|date=23 November 1907}}</ref><ref>[http://marconi100.ca/clip/marconi-sydpost19071024.html Second Test of the Marconi Over-Ocean Wireless System Proved Entirely Successful] {{Webarchive|url=https://web.archive.org/web/20131019025942/http://marconi100.ca/clip/marconi-sydpost19071024.html |date=19 October 2013 }}. ''Sydney Daily Post''. 24 October 1907.</ref> between [[Clifden]], Ireland, and [[Glace Bay]], but even after this the company struggled for many years to provide reliable communication to others.

Marconi's apparatus is also credited with saving the 700 people who survived the tragic ''[[Titanic]]'' disaster.<ref name="A Short History of Radio">[http://transition.fcc.gov/omd/history/radio/documents/short_history.pdf "A Short History of Radio"], Winter 2003–2004  (FCC.gov)</ref>

==Audio transmission==

[[File:Reginald Fessenden, probably 1906.jpg|thumb|Reginald Fessenden (around 1906)]]

In the late 1890s, Canadian-American inventor [[Reginald Fessenden]] came to the conclusion that he could develop a far more efficient system than the spark-gap transmitter and coherer receiver combination.<ref>''The Continuous Wave'' by Hugh G. J. Aitken, 1985, p. 50.</ref><ref>Fessenden, Helen (1940), [https://babel.hathitrust.org/cgi/pt?id=uc1.b4540711&view=1up&seq=74 pp. 60–61, 76].</ref> To this end he worked on developing a high-speed alternator (referred to as "an alternating-current dynamo") that generated "pure sine waves" and produced "a continuous train of radiant waves of substantially uniform strength", or, in modern terminology, a  [[continuous wave|continuous-wave]] (CW) transmitter.<ref>{{patent|US|706737|patent: "Wireless Telegraphy"}}</ref> While working for the [[United States Weather Bureau]] on [[Cobb Island (Maryland)|Cobb Island]], Maryland, Fessenden researched using this setup for audio transmissions via radio. By fall of 1900, he successfully transmitted speech over a distance of about 1.6 kilometers (one mile),<ref name="experiments">"Experiments and Results in Wireless Telephony" by John Grant, ''The American Telephone Journal''. [https://babel.hathitrust.org/cgi/pt?id=mdp.39015057240221&view=1up&seq=111 Part I]: January 26, 1907, pp. 49–51; [https://babel.hathitrust.org/cgi/pt?id=mdp.39015057240221&view=1up&seq=147 Part II]: February 2, 1907, pp. 68–70, 79–80.</ref> which appears to have been the first successful audio transmission using radio signals.<ref>T. K. Sarkar, Robert Mailloux, Arthur A. Oliner, [[Magdalena Salazar Palma]], Dipak L. Sengupta, ''History of Wireless'', Wiley – 2006, p. 92</ref><ref>John W. Klooster, ''Icons of Invention – The Makers of the Modern World from Gutenberg to Gates'' – Vol. 1, Greenwood Press – 2009, p. 400</ref> Although successful, the sound transmitted was far too distorted to be commercially practical.<ref>Hugh G. J. Aitken, ''The Continuous Wave: Technology and American Radio, 1900–1932''. Princeton University Press. Princeton, New Jersey – 1985,  p. 61</ref> According to some sources, notably Fessenden's wife Helen's biography, on [[Christmas Eve]] 1906, [[Reginald Fessenden]] used an [[Alexanderson alternator]] and rotary [[spark-gap transmitter]] to make the first radio audio broadcast, from [[Ocean Bluff-Brant Rock, Massachusetts|Brant Rock, Massachusetts]]. Ships at sea heard a broadcast that included Fessenden playing ''[[O Holy Night]]'' on the [[violin]] and reading a passage from the [[Bible]].<ref>[https://archive.org/details/radioindustrysto00harvrich/page/190/mode/1up "The Early History of Radio in the United States"] by H. P. Davis, in ''The Radio Industry: The Story of its Development'', 1928, p. 190.</ref><ref>Helen M. Fessenden, ''Reginald Fessenden: Builder of Tomorrow'', New York: Coward-McCann, 1940</ref>

Around the same time American inventor [[Lee de Forest]] experimented with an [[arc converter|arc transmitter]], which unlike the discontinuous pulses produced by spark transmitters, created steady "continuous wave" signal that could be used for [[amplitude modulated]] (AM) audio transmissions. In February 1907 he transmitted electronic [[telharmonium]] music from his laboratory station in New York City.<ref>''Father of Radio'' by Lee de Forest, 1950, p. 225.</ref> This was followed by tests that included, in the fall, [[Eugenia Farrar]] singing "I Love You Truly".<ref>[https://babel.hathitrust.org/cgi/pt?id=mdp.39015020686641&view=1up&seq=60 ''I Looked and I Listened''] by Ben Gross, 1954, p. 48.</ref> In July 1907 he made ship-to-shore transmissions by radiotelephone—race reports for the Annual Inter-Lakes Yachting Association (I-LYA) Regatta held on [[Lake Erie]]—which were sent from the steam yacht ''Thelma'' to his assistant, Frank E. Butler, located in the Fox's Dock Pavilion on [[South Bass Island]].<ref>[https://archive.org/stream/electricalworld50newy#page/293/mode/1up "Reporting Yacht Races by Wireless Telephony"], ''Electrical World'', August 10, 1907, pp. 293–94. (archive.org)</ref>

===Broadcasting===
{{See also|Old-time radio|History of broadcasting|Radio broadcasting#History|AM broadcasting#History|FM broadcasting#History}}

The Dutch company ''Nederlandsche Radio-Industrie'' and its owner-engineer, [[Hanso Idzerda]], made its first regular entertainment radio broadcast over station [[PCGG]] from its workshop in [[The Hague]] on 6 November 1919. The company manufactured both transmitters and receivers. Its popular program was broadcast four nights per week using narrow-band FM transmissions on 670 metres (448&nbsp;kHz),<ref>[[:File:Soireé-Musicale.jpg|"Radio Soireé-Musicale"]] ''Nieuwe Rotterdamsche Courant'', 05 November 1919, p. 16</ref> until 1924 when the company ran into financial trouble.

Regular entertainment broadcasts began in [[Argentina]], pioneered by [[Enrique Telémaco Susini]] and his associates. At 9 pm on August 27, 1920, Sociedad Radio Argentina aired a live performance of Richard Wagner's opera ''Parsifal'' from the Coliseo Theater in downtown [[Buenos Aires]]. Only about twenty homes in the city had receivers to tune in this program.

On 31 August 1920 the ''[[Detroit News]]''  began publicized daily news and entertainment "Detroit News Radiophone" broadcasts, originally as licensed amateur station 8MK, then later as WBL and [[WWJ (AM)|WWJ]] in [[Detroit|Detroit, Michigan]].

Union College in Schenectady, [[New York (state)|New York]] began broadcasting on October 14, 1920, over [[WRUC|2ADD]], an amateur station licensed to Wendell King, an [[African-American]] student at the school.<ref name="Radio Broadcasting">{{cite web|url=http://w2uc.union.edu/RADIO_web.htm |title=Radio Broadcasting at Union College|publisher=W2UC.union.edu |author=Rowan Wakefield|date=February 1959|access-date=2009-07-22 |url-status=dead |archive-url=https://web.archive.org/web/20080515103959/http://w2uc.union.edu/RADIO_web.htm |archive-date=May 15, 2008}}</ref> Broadcasts included a series of Thursday night concerts initially heard within a {{convert|100|mi|adj=on}} radius and later for a {{convert|1000|mi|adj=on}} radius.<ref name="Radio Broadcasting"/><ref>{{cite web|title=From a Shed to the World Wide Web|publisher=Union College Magazine|access-date=2018-02-03 |url=https://muse.union.edu/newsarchives/1995/11/01/from-a-shed-to-the-world-wide-web/|date=1 November 1995}}</ref>

In 1922 regular audio broadcasts for entertainment began in the UK from the [[Guglielmo Marconi|Marconi]] Research Centre [[2MT]] at [[Writtle]] near [[Chelmsford, England]].

==== Wavelength and frequency  ====
In early radio, and to a limited extent much later, the transmission signal of the radio station was specified in meters, referring to the [[wavelength]], the length of the radio wave. This is the origin of the terms [[long wave]], [[medium wave]], and [[short wave]] radio.<ref>{{Cite web|title=Radio Waves and the Electromagnetic Spectrum|url=https://radiojove.gsfc.nasa.gov/education/lesson_plans/lesson4.pdf|website=radiojove}}</ref> Portions of the radio spectrum reserved for specific purposes were often referred to by wavelength: the [[40-meter band]], used for [[History of amateur radio|amateur radio]], for example. The relation between wavelength and frequency is reciprocal: the higher the frequency, the shorter the wave, and vice versa.

As equipment progressed, precise frequency control became possible; early stations often did not have a precise frequency, as it was affected by the temperature of the equipment, among other factors. Identifying a radio signal by its frequency rather than its length proved much more practical and useful, and starting in the 1920s this became the usual method of identifying a signal, especially in the United States. Frequencies specified in number of cycles per second (kilocycles, megacycles) were replaced by the more specific designation of [[hertz]] (cycles per second) about 1965.

==Radio companies==

[[File:Donald Manson working as an employee of the Marconi Company.jpg|thumb|222px|Donald Manson working as an employee of the Marconi Company (England, 1906)]]

===British Marconi===
Using various [[patent]]s, the [[Marconi Company|British Marconi]] company was established in 1897 by Guglielmo Marconi and began communication between [[coast radio station]]s and ships at sea.<ref>{{Cite web|title=Marconi Company Limited {{!}} Science Museum Group Collection|url=https://collection.sciencemuseumgroup.org.uk/people/cp18089/marconi-company-limited|website=collection.sciencemuseumgroup.org.uk|language=en|access-date=2020-05-27}}</ref> A year after, in 1898, they successfully introduced their first radio station in Chelmsford. This company, along with its subsidiaries [[Canadian Marconi Company|Canadian Marconi]] and [[Marconi Wireless Telegraph Company of America|American Marconi]], had a stranglehold on ship-to-shore communication. It operated much the way [[AT&T Corporation|American Telephone and Telegraph]] operated until 1983, owning all of its equipment and refusing to communicate with non-Marconi equipped ships. Many inventions improved the quality of radio, and amateurs experimented with uses of radio, thus planting the first seeds of broadcasting.

===Telefunken===
The company [[Telefunken]] was founded on May 27, 1903, as "Telefunken society for wireless telefon" of [[Siemens & Halske]] (S & H) and the [[AEG (German company)|Allgemeine Elektrizitäts-Gesellschaft (''General Electricity Company'')]] as joint undertakings for radio engineering in Berlin.<ref>{{Cite web|title=History & Origin|url=https://www.telefunken-elektroakustik.com/history|website=Telefunken Elektroakustik|language=en-US|access-date=2020-05-27|archive-date=2020-04-23|archive-url=https://web.archive.org/web/20200423144312/https://www.telefunken-elektroakustik.com/history|url-status=dead}}</ref> It continued as a joint venture of [[AEG (German company)|AEG]] and [[Siemens AG]], until Siemens left in 1941. In 1911, [[Kaiser Wilhelm II]] sent Telefunken engineers to [[West Sayville, New York|West Sayville]], [[New York (state)|New York]] to erect three 600-foot (180-m) radio towers there. Nikola Tesla assisted in the construction. A similar station was erected in [[Nauen]], creating the only wireless communication between North America and Europe.

==Technological development==

===Amplitude-modulated (AM)===
The invention of amplitude-modulated (AM) radio, which allows more closely spaced  stations to simultaneously send signals (as opposed to spark-gap radio, where each transmission occupies a wide bandwidth) is attributed to [[Reginald Fessenden]], [[Valdemar Poulsen]] and [[Lee de Forest]].

===Crystal set receivers===
[[File:NBS 120 Set.jpg|thumb|left|In the 1920s, the [[Copyright status of works by the federal government of the United States|United States government publication]], "''Construction and Operation of a Simple Homemade Radio Receiving Outfit''", showed how almost any person handy with simple tools could a build an effective [[crystal radio]] receiver.]]

The most common type of receiver before vacuum tubes was the [[crystal radio|crystal set]], although some early radios used some type of amplification through electric current or battery. Inventions of the [[triode amplifier]], [[motor–generator]], and [[detector (radio)|detector]] enabled audio radio. The use of [[amplitude modulation]] ([[AM radio|AM]]), by which soundwaves can be transmitted over a continuous-wave radio signal of narrow bandwidth (as opposed to spark-gap radio, which sent rapid strings of damped-wave pulses that consumed much bandwidth and were only suitable for Morse-code telegraphy) was pioneered by Fessenden, Poulsen and Lee de Forest.<ref>{{Cite book|last=Basalla|first=George|title=The Evolution of Technology|publisher=Cambridge University Press|year=1988|pages=44}}</ref>

The art and science of crystal sets is still pursued as a hobby in the form of simple un-amplified radios that 'runs on nothing, forever'. They are used as a teaching tool by groups such as the [[Boy Scouts of America]] to introduce youngsters to electronics and radio. As the only energy available is that gathered by the antenna system, loudness is necessarily limited.

===Vacuum tubes===
[[File:First vacuum tube AM radio transmitter.jpg|thumb|The first commercial AM [[Audion]] [[vacuum tube]] [[Transmitter|radio transmitter]], built in 1914 by [[Lee De Forest]] who invented the Audion ([[triode]]) in 1906]]
During the mid-1920s, amplifying [[vacuum tube]]s revolutionized [[radio receiver]]s and [[transmitter]]s. [[John Ambrose Fleming]] developed a vacuum tube [[diode]]. [[Lee de Forest]] placed a screen, added a [[Control grid|"grid" electrode]], creating the [[triode]].<ref>{{Cite web|title=Vacuum Tube Radio |url=https://www.nps.gov/features/safr/feat0001/virtualships/vrmovies/muvr2hs11.htm|website=nps.gov|access-date=2020-05-27}}</ref>

Early radios ran the entire power of the transmitter through a [[carbon microphone]]. In the 1920s, the [[Westinghouse Electric (1886)|Westinghouse company]] bought Lee de Forest's and [[Edwin Armstrong]]'s patent. During the mid-1920s, Amplifying [[vacuum tube]]s revolutionized [[radio receiver]]s and transmitters. Westinghouse engineers developed a more modern vacuum tube.

The first radios still required batteries, but in 1926 the "[[battery eliminator]]" was introduced to the market. This tube technology allowed radios to be powered through the grid instead. They still required batteries to heat up the vacuum-tube filaments, but after the invention of [[Hot cathode|indirectly heated vacuum tubes]], the first completely battery free radios became available in 1927.<ref>[https://books.google.com/books?id=IAjtEeVtXqAC&dq=Canadian+inventor+E.S.+Rogers+1925+1926+1927+Battery+Eliminator+indirectly+heated+vacuum+tubes&pg=PA67 The Race for Wireless: How Radio was Invented (or Discovered?)]</ref>

In 1929 a new screen grid tube called UY-224 was introduced, an amplifier designed to operate directly on alternating current.<ref>[https://books.google.com/books?id=hygDAAAAMBAJ&dq=A.C.+screen+grid+tube+UY-224+1929&pg=PA71 Popular Science Aug 1929]</ref>

A problem with the early radios was fading stations and fluctuating volume. The invention of the [[superheterodyne receiver]] solved this problem, and the first radios with a heterodyne radio receiver went for sale in 1924. But it was costly, and the technology was shelved while waiting for the technology to mature, and in 1929 the Radiola 66 and Radiola 67 went for sale.<ref>[https://www.saturdayeveningpost.com/sep-keyword/late-1920s/ late 1920s Archives | The Saturday Evening Post]</ref><ref>[https://www.wshu.org/vintage-radio/2014-06-11/a-radio-for-the-great-depression A Radio for the Great Depression – WSHU]</ref><ref>[https://books.google.com/books?id=Ck9IGgEFeeoC&dq=Radiola+66+superheterodyne+1929&pg=PA340 Radiola: The Golden Age of RCA, 1919–1929]</ref>

===Loudspeakers===
In the early days one had to use headphones to listen to radio. Later loudspeakers in the form of a horn of the type used by phonographs, equipped with a telephone receiver, became available. But the sound quality was poor. In 1926 the first radios with electrodynamic loudspeakers went for sale, which improved the quality significantly. At first the loudspeakers were separated from the radio, but soon radios would come with a built-in loudspeaker.<ref>[https://books.google.com/books?id=tsT9kq4m_G8C&dq=Radiola+Model+104+Tractrix+horn+magnets&pg=PT323 Audio Engineering Explained]</ref>

Other inventions related to sound included the automatic volume control (AVC), first commercially available in 1928.<ref>[https://californiahistoricalradio.com/wp-content/uploads/2021/12/CHRS-Journal-Volume-8-No.-6-1984-Nov-Dec.pdf JI f()IU 112~ A\ IL – California Historical Radio Society]</ref> In 1930 a tone control knob was added to the radios. This allowed listeners to improve imperfect broadcasting.<ref>[https://books.google.com/books?id=sygDAAAAMBAJ&dq=%22Radio+Now+Has+Tone+Control%22&pg=PA84 Popular Science des 1930]</ref>

The [[magnetic cartridge]], which was introduced in the mid 20's, greatly improved the broadcasting of music. When playing music from a phonograph before the magnetic cartridge, a microphone had to be placed close to a horn loudspeaker. The invention allowed the electric signals to be amplified and then fed directly to the [[broadcast transmitter]].<ref>[https://books.google.com/books?id=3u-bCgAAQBAJ&dq=1925+paper+not+only+summarized+the+state+of+the+art+but+also+presented+a+new+loudspeaker+design&pg=PA159 Dawn of the Electronic Age: Electrical Technologies in the Shaping of the Modern World, 1914 to 1945]</ref>

===Transistor technology===
[[File:Vintage Regency TR-1 4-Transistor Radio, Mandarin Red, Made in USA, Introduced In 1954 (8622359295).jpg|thumb|upright|The [[Regency TR-1]], which used [[Texas Instruments]]' [[NPN transistor]]s, was the world's first commercially produced [[transistor radio]] in 1954. Size: 3×5×1.25 inch (7.6×12.7×3.2 cm)]]

Following development of [[transistor]] technology, [[bipolar junction transistor]]s led to the development of the [[transistor radio]]. In 1954, the Regency company introduced a pocket transistor radio, the [[Regency TR-1|TR-1]], powered by a "standard 22.5 V Battery." In 1955, the newly formed [[Sony]] company introduced its first transistorized radio, the [[TR-55]].<ref name="pbs">{{cite web |url=https://www.pbs.org/transistor/background1/events/tradio.html |title=Transistor Radios |year=1999 |publisher=ScienCentral (pbs.org)|access-date=2018-02-03}}</ref> It was small enough to fit in a [[Waistcoat|vest]] pocket, powered by a small battery. It was durable, because it had no vacuum tubes to burn out. In 1957, Sony introduced the TR-63, the first mass-produced transistor radio, leading to the mass-market penetration of transistor radios.<ref name="Skrabec">{{cite book|last1=Skrabec| first1=Quentin R. Jr. |url=https://books.google.com/books?id=2kc69qrid9oC&pg=PA195|title=The 100 Most Significant Events in American Business: An Encyclopedia|date=2012|publisher=ABC-CLIO|isbn=978-0313398636|pages=195–97}}</ref> Over the next 20 years, transistors replaced tubes almost completely except for high-power [[transmitter]]s.

By the mid-1960s, the [[Radio Corporation of America]] (RCA) were using [[metal–oxide–semiconductor field-effect transistor]]s (MOSFETs) in their consumer products, including [[FM radio]], television and [[amplifier]]s.<ref name="Harrison">{{cite book|last1=Harrison|first1=Linden T.|url=https://books.google.com/books?id=03JmxpE39N4C&pg=PA185|title=Current Sources and Voltage References: A Design Reference for Electronics Engineers|date=2005|publisher=Elsevier|isbn=978-0080455556|page=185}}</ref> [[Metal–oxide–semiconductor]] (MOS) [[large-scale integration]] (LSI) provided a practical and economic solution for radio technology, and was used in [[mobile radio]] systems by the early 1970s.<ref name="Zeidler">{{cite journal|last1=Zeidler|first1=G.|last2=Becker|first2=D.|date=1974|title=MOS LSI Custom Circuits Offer New Prospects for Communications Equipment Design|url=https://books.google.com/books?id=TihQAAAAYAAJ|journal=Electrical Communication|publisher=[[Western Electric Company]]|volume=49–50|pages=88–92|quote=In many fields of communications equipment design, MOS LSI custom built circuits provide the only practical and economic solution. (...) A complete list of all applications is beyond the scope of this paper since new MOS developments are constantly being initiated in the various technical areas. Typical examples of completed and present MOS developments are:<br />— crosspoints<br />— multiplexers<br />— modems<br />— mobile radios}}</ref>

===Integrated circuit===
The first integrated circuit (IC) radio, P1740 by [[General Electric]], became available in 1966.<ref>[https://worldradiohistory.com/Archive-Electronics-World/60s/1966/Electronics-World-1966-11.pdf Electronics World (November, 1966, Vol. 76, No. 51. p. 44)]</ref>

===Car radio===
The first car radio was introduced in 1922, but it was so large that it took up too much space in the car.<ref>[https://techhistorian.com/first-car-with-radio/ The First Car With a Radio – Techhistorian]</ref> The first commercial car radio that could easily be installed in most cars went for sale in 1930.<ref>[https://www.thewellnews.com/fourth-estate/can-am-radio-be-saved-should-it-be/ Can AM Radio Be Saved? Should It Be? | The Well News]</ref><ref>[https://mashhua.com/detail/2070 Entrepreneur – Founder Of Motorola – Paul Galvin]</ref>

== Radio telex ==
[[Telegraphy]] did not go away on radio. Instead, the degree of automation increased. On land-lines in the 1930s, [[teletypewriter]]s automated encoding, and were adapted to pulse-code dialing to automate routing, a service called [[teleprinter|telex]]. For thirty years, telex was the cheapest form of long-distance communication, because up to 25 telex channels could occupy the same bandwidth as one voice channel. For business and government, it was an advantage that telex directly produced written documents.

Telex systems were adapted to short-wave radio by sending tones over [[single sideband]]. [[ITU-T|CCITT]] R.44 (the most advanced pure-telex standard) incorporated character-level error detection and retransmission as well as automated encoding and routing. For many years, telex-on-radio (TOR) was the only reliable way to reach some third-world countries. TOR remains reliable, though less-expensive forms of e-mail are displacing it. Many national telecom companies historically ran nearly pure telex networks for their governments, and they ran many of these links over short wave radio.

Documents including maps and photographs went by [[radiofax]], or wireless photoradiogram, invented in 1924 by [[Richard H. Ranger]] of [[Radio Corporation of America]] (RCA). This method prospered in the mid-20th century and faded late in the century.

==Radio navigation==
One of the first developments in the early 20th century was that aircraft used commercial AM radio stations for navigation, AM stations are still marked on U.S. aviation charts. [[Radio navigation]] played an important role during war time, especially in World War II. Before the discovery of the crystal oscillator, radio navigation had many limits.<ref>{{Cite web|title="Flying the Beam" {{!}} Time and Navigation|url=http://timeandnavigation.si.edu/navigating-air/challenges/overcoming-challenges/radio-navigation|access-date=2020-06-09|website=timeandnavigation.si.edu|language=en}}</ref> However, as radio technology expanding, navigation is easier to use, and it provides a better position. Although there are many advantages, the radio navigation systems often comes with complex equipment such as the radio compass receiver, compass indicator, or the radar plan position indicator. All of these require users to obtain certain knowledge.

In the 1960s [[VHF omnidirectional range|VOR]] systems became widespread. In the 1970s, [[LORAN]] became the premier radio navigation system. Soon, the US Navy experimented with [[satellite navigation]]. In 1987, the [[Global Positioning System]] (GPS) constellation of [[satellite]]s was launched; it was followed by other [[GNSS]] systems like [[Glonass]], [[BeiDou]] and [[Galileo (satellite navigation)|Galileo]].

==FM==

In 1933, [[FM radio]] was patented by inventor [[Edwin Armstrong|Edwin H. Armstrong]].<ref>{{Cite web|title=Edwin H. Armstrong {{!}} Lemelson-MIT Program|url=https://lemelson.mit.edu/resources/edwin-h-armstrong|archive-url=https://web.archive.org/web/20150906023156/http://lemelson.mit.edu/resources/edwin-h-armstrong|url-status=dead|archive-date=September 6, 2015|website=lemelson.mit.edu|access-date=2020-05-28}}</ref> FM uses [[frequency modulation]] of the radio wave to reduce [[White noise|static]] and [[Radio frequency interference|interference]] from electrical equipment and the atmosphere. In 1937, [[WGTR (Massachusetts)|W1XOJ]], the first experimental FM radio station after Armstrong's [[W2XMN]] in Alpine, New Jersey, was granted a construction permit by the US [[Federal Communications Commission]] (FCC).

===FM in Europe===

After World War II, [[FM radio]] broadcasting was introduced in Germany. At a meeting in [[Copenhagen]] in 1948, a new [[wavelength plan]] was set up for Europe. Because of the recent war, Germany (which did not exist as a state and so was not invited) was only given a small number of [[Mediumwave|medium-wave]] frequencies, which were not very good for broadcasting. For this reason Germany began broadcasting on UKW ("Ultrakurzwelle", i.e. ultra short wave, nowadays called [[Very high frequency|VHF]]) which was not covered by the Copenhagen plan. After some [[amplitude modulation]] experience with VHF, it was realized that FM radio was a much better alternative for VHF radio than AM. Because of this history, FM radio is still referred to as "UKW Radio" in Germany. Other European nations followed a bit later, when the superior sound quality of FM and the ability to run many more local stations because of the more limited range of VHF broadcasts were realized.

==Television==
{{Further|History of television}}

In the 1930s, regular [[analog television]] broadcasting began in some parts of Europe and North America. By the end of the decade there were roughly 25,000 all-electronic television receivers in existence worldwide, the majority of them in the UK. In the US, Armstrong's FM system was designated by the FCC to transmit and receive television sound.

===Color television===
* 1953: [[NTSC]] compatible [[color television]] introduced in the US.
* 1962: [[Telstar|Telstar 1]], the first [[communications satellite]], relayed the first publicly available live transatlantic [[television]] signal.
* Mid-1960s: [[Metal–oxide–semiconductor field-effect transistor]] (MOSFET) first used for television, by the [[RCA|Radio Corporation of America]] (RCA).<ref name="Harrison" /> The [[power MOSFET]] was later widely adopted for [[television receiver]] circuits.<ref>{{cite book|last1=Amos|first1=S. W.|url=https://books.google.com/books?id=11EvBQAAQBAJ&pg=PA332|title=Principles of Transistor Circuits: Introduction to the Design of Amplifiers, Receivers and Digital Circuits|last2=James|first2=Mike|date=2013|publisher=[[Elsevier]]|isbn=978-1483293905|page=332}}</ref>

By 1963, [[color television]] was being broadcast commercially (though not all broadcasts or programs were in color), and the first (radio) [[communications satellite|communication satellite]], ''[[Telstar]]'', was launched. In the 1970s,

==Mobile phones==
{{Main|History of mobile phones}}

In 1947 AT&T commercialized the [[Mobile Telephone Service]]. From its start in St. Louis in 1946, AT&T then introduced Mobile Telephone Service to one hundred towns and highway corridors by 1948. Mobile Telephone Service was a rarity with only 5,000 customers placing about 30,000 calls each week. Because only three radio channels were available, only three customers in any given city could make mobile telephone calls at one time.<ref name=GS2006>Gordon A. Gow, Richard K. Smith ''Mobile and wireless communications: an introduction'', McGraw-Hill International, 2006 {{ISBN|0335217613}} p. 23</ref> Mobile Telephone Service was expensive, costing US$15 per month, plus $0.30–0.40 per local call, equivalent to (in 2012 US dollars) about $176 per month and $3.50–4.75 per call.<ref name=att1946>{{cite web |url= http://www.corp.att.com/attlabs/reputation/timeline/46mobile.html |title= 1946: First Mobile Telephone Call |year= 2011 |work= corp.att.com |publisher= AT&T Intellectual Property |access-date= 2012-04-24 |archive-date= 2012-12-12 |archive-url= https://web.archive.org/web/20121212113039/http://www.corp.att.com/attlabs/reputation/timeline/46mobile.html |url-status= dead }}</ref> The [[Advanced Mobile Phone System]] analog mobile phone system, developed by [[Bell Labs]], was introduced in the Americas in 1978,<ref name = "Testing the First Cell Phone Network">{{cite web |author=AT&T Tech Channel |url=http://techchannel.att.com/play-video.cfm/2011/6/13/AT%26T-Archives-AMPS%3A-coming-of-age |title=AT&T Archives: Testing the First Public Cell Phone Network |publisher=Techchannel.att.com |date=2011-06-13 |access-date=2013-09-28 |archive-date=2013-10-29 |archive-url=https://web.archive.org/web/20131029194138/http://techchannel.att.com/play-video.cfm/2011/6/13/AT%26T-Archives-AMPS%3A-coming-of-age |url-status=dead }}</ref><ref name="PrivateLine">[http://www.privateline.com/dailynotes/index13.html Private Line: Daily Notes Archive (October 2003)]  by Tom Farley {{webarchive|url=https://web.archive.org/web/20120610001231/http://www.privateline.com/dailynotes/index13.html |date=2012-06-10 }}.</ref><ref name = "MilestonesPast">[http://www.milestonespast.com/exbringing.htm  "Turning on the Future: October 13, 1983"] {{Webarchive|url=https://web.archive.org/web/20111006011650/http://www.milestonespast.com/exbringing.htm |date=October 6, 2011 }} by Kathi Ann Brown (extract from ''Bringing Information to People'', 1993) (MilestonesPast.com)</ref> gave much more capacity. It was the primary analog mobile phone system in North America (and other locales) through the 1980s and into the 2000s.

The development of [[metal–oxide–semiconductor]] (MOS) [[large-scale integration]] (LSI) technology, [[information theory]] and [[cellular network]]ing led to the development of affordable [[mobile communications]].<ref name="Srivastava">{{cite book |last1=Srivastava |first1=Viranjay M. |url=https://books.google.com/books?id=fkO9BAAAQBAJ&pg=PA1 |title=MOSFET Technologies for Double-Pole Four-Throw Radio-Frequency Switch |last2=Singh |first2=Ghanshyam |date=2013 |publisher=[[Springer Science & Business Media]] |isbn=978-3319011653 |page=1}}</ref> The [[Advanced Mobile Phone System]] analog mobile phone system, developed by [[Bell Labs]] and introduced in the [[Americas]] in 1978,<ref name="Testing the First Cell Phone Network" /><ref name="PrivateLine" /><ref name="MilestonesPast" /> gave much more capacity. It was the primary analog mobile phone system in [[North America]] (and other locales) through the 1980s and into the 2000s.

==Broadcast and copyright==

The British government and the state-owned postal services found themselves under massive pressure from the wireless industry (including telegraphy) and early radio adopters to open up to the new medium. In an internal confidential report from February 25, 1924, the ''Imperial Wireless Telegraphy Committee'' stated:

:"We have been asked 'to consider and advise on the policy to be adopted as regards the Imperial Wireless Services so as to protect and facilitate public interest.' It was impressed upon us that the question was urgent. We did not feel called upon to explore the past or to comment on the delays which have occurred in the building of the Empire Wireless Chain. We concentrated our attention on essential matters, examining and considering the facts and circumstances which have a direct bearing on policy and the condition which safeguard public interests."<ref>''Report of the Imperial Wireless Telegraphy Committee, 1924. Presented to Parliament by Command of His Majesty.'' [[The National Archives (United Kingdom)|National Archives]], London, Reference: CAB 24/165/38</ref>

When radio was introduced in the early 1920s, many predicted it would kill the [[phonograph record]] industry. Radio was a free medium for the public to hear music for which they would normally pay. While some companies saw radio as a new avenue for promotion, others feared it would cut into profits from record sales and live performances. Many record companies would not license their records to be played over the radio, and had their major stars sign agreements that they would not perform on radio broadcasts.<ref>{{Cite web|title=liebowitz.dvi<!-- Bot generated title -->|url=http://www.serci.org/docs/liebowitz.pdf|url-status=dead|archive-url=https://web.archive.org/web/20061229090155/http://www.serci.org/docs/liebowitz.pdf|archive-date=2006-12-29|access-date=2006-11-12}}</ref><ref>{{cite web|title=Chronology: Technology And The Music Industry|url=https://www.pbs.org/wgbh/pages/frontline/shows/music/inside/cron.html|author=Callie Taintor|date=27 May 2004|work=Frontline: The Way the Music Died (Inside the Music Industry) (PBS.org)}}</ref>

Indeed, the music recording industry had a severe drop in profits after the introduction of the radio. For a while, it appeared as though radio was a definite threat to the record industry. Radio ownership grew from two out of five homes in 1931 to four out of five homes in 1938. Meanwhile, record sales fell from $75 million in 1929 to $26 million in 1938 (with a low point of $5 million in 1933), though the economics of the situation were also affected by the [[Great Depression]].<ref>{{cite web|title=Creativity Wants to be Paid|url=http://www.edwardsamuels.com/copyright/beyond/articles/csusa6.htm|author=Edward Samuels|date=April 19, 2002|work=edwardsamuels.com|access-date=November 12, 2006|archive-date=October 30, 2006|archive-url=https://web.archive.org/web/20061030102850/http://www.edwardsamuels.com/copyright/beyond/articles/csusa6.htm|url-status=dead}}</ref>

The copyright owners were concerned that they would see no gain from the popularity of radio and the 'free' music it provided. What they needed to make this new medium work for them already existed in previous copyright law. The copyright holder for a song had control over all public performances 'for profit.' The problem now was proving that the radio industry, which was just figuring out for itself how to make money from advertising and currently offered free music to anyone with a receiver, was making a profit from the songs.

The [[test case (law)|test case]] was against [[Bamberger's]] Department Store in [[Newark, New Jersey]] in 1922. The store was broadcasting music from its store on the radio station WOR. No advertisements were heard, except at the beginning of the broadcast which announced "L. Bamberger and Co., One of America's Great Stores, Newark, New Jersey." It was determined through this and previous cases (such as the lawsuit against Shanley's Restaurant) that Bamberger was using the songs for commercial gain, thus making it a public performance for profit, which meant the copyright owners were due payment.

With this ruling the [[American Society of Composers, Authors and Publishers]] (ASCAP) began collecting licensing fees from radio stations in 1923. The beginning sum was $250 for all music protected under ASCAP, but for larger stations the price soon ballooned to $5,000. Edward Samuels reports in his book ''The Illustrated Story of Copyright'' that "radio and TV licensing represents the single greatest source of revenue for ASCAP and its composers […] and [a]n average member of ASCAP gets about $150–$200 per work per year, or about $5,000-$6,000 for all of a member's compositions." Not long after the Bamberger ruling, ASCAP had to once again defend their right to charge fees, in 1924. The Dill Radio Bill would have allowed radio stations to play music without paying and licensing fees to ASCAP or any other music-licensing corporations. The bill did not pass.<ref>{{cite web|title=Music and Sound Recordings (chapter two)|url=http://www.edwardsamuels.com/illustratedstory/isc2.htm|date=2002|work=The Illustrated Story of Copyright (edwardsamuels.com)|access-date=2006-11-12|archive-date=2006-10-30|archive-url=https://web.archive.org/web/20061030102206/http://www.edwardsamuels.com/illustratedstory/isc2.htm|url-status=dead}}</ref>

== Regulations of radio stations in the U.S ==

=== Wireless Ship Act of 1910 ===
Radio technology was first used for ships to communicate at sea. To ensure safety, the [[Wireless Ship Act of 1910]] marks the first time the U.S. government implies regulations on radio systems on ships.<ref>{{Cite web|last=Tullai|first=Margaret|title=Wireless Ship Act of 1910|url=https://www.mtsu.edu/first-amendment/article/1052/wireless-ship-act-of-1910|access-date=2020-05-30|website=www.mtsu.edu|language=en}}</ref> This act requires ships to have a radio system with a professional operator if they want to travel more than 200 miles offshore or have more than 50 people on board. However, this act had many flaws including the competition of [[radio operator]]s including the two majors company (British and American Marconi). They tended to delay communication for ships that used their competitor's system. This contributed to the tragic incident of the sinking of the [[Titanic]] in 1912.

=== Radio Act of 1912 ===
In 1912, distress calls to aid the sinking ''Titanic'' were met with a large amount of interfering radio traffic, severely hampering the rescue effort. Subsequently, the US government passed the [[Radio Act of 1912]] to help mitigate the repeat of such a tragedy. The act helps distinguish between normal radio traffic and (primarily maritime) emergency communication, and specifies the role of government during such an emergency.<ref>{{Cite web|last=Morrison|first=Sharon L.|title=Radio Act of 1912|url=https://www.mtsu.edu/first-amendment/article/1090/radio-act-of-1912|access-date=2020-05-30|website=www.mtsu.edu|language=en}}</ref>

=== The Radio Act of 1927 ===
The [[Radio Act of 1927]] gave the [[Federal Radio Commission]] the power to grant and deny licenses, and to assign frequencies and power levels for each licensee. In 1928 it began requiring licenses of existing stations and setting controls on who could broadcast from where on what frequency and at what power. Some stations could not obtain a license and ceased operations. In section 29, the Radio Act of 1927 mentioned that the content of the broadcast should be freely present, and the government cannot interfere with this.<ref>{{Cite web|last=Morrison|first=Sharon L.|title=Radio Act of 1927|url=https://www.mtsu.edu/first-amendment/article/1091/radio-act-of-1927|access-date=2020-05-30|website=www.mtsu.edu|language=en}}</ref>

=== The Communications Act of 1934 ===
The introduction of the [[Communications Act of 1934]] led to the establishment of the Federal Communications Commissions (FCC). The FCC's responsibility is to control the industry including "telephone, telegraph, and radio communications."<ref>{{Cite web|title=The Communications Act of 1934|url=https://it.ojp.gov/PrivacyLiberty/authorities/statutes/1288|access-date=2020-06-09|website=it.ojp.gov}}</ref> Under this Act, all carriers have to keep records of authorized interference and unauthorized interference. This Act also supports the President in time of war. If the government needs to use the communication facilities in time of war, they are allowed to.

=== The Telecommunications Act of 1996 ===
The [[Telecommunications Act of 1996]] was the first significant overhaul in over 60 years amending the work of the Communications Act of 1934. Coming only two dozen years after the breakup of AT&T, the act sets out to move telecommunications into a state of competition with their markets and the networks they are a part of.<ref>{{Cite journal|last=Economides|first=Nicholas|date=1999-12-01|title=The Telecommunications Act of 1996 and its impact1Presented at the Annual Telecommunications Policy Conference, Tokyo, Japan, 4 December 1997. I thank Hajime Hori, Bob Kargoll, Steve Levinson, and two anonymous referees for helpful comments.1|journal=Japan and the World Economy|language=en|volume=11|issue=4|pages=455–83|doi=10.1016/S0922-1425(98)00056-5|issn=0922-1425|doi-access=free}}</ref> Up to this point the effects of the Telecommunications Act of 1996 have been seen, but some of the changes the Act set out to fix are still ongoing problems, such as being unable to create an open competitive market.

== Licensed commercial public radio stations ==
[[File:Brox (Sisters) LCCN2014717186.jpg|thumb|Around 1920, radio broadcasting started to get popular. The [[Brox Sisters]], a popular singing group, gathered around the radio at the time.]]
The question of the 'first' publicly targeted licensed radio station in the U.S. has more than one answer and depends on semantics. Settlement of this 'first' question may hang largely upon what constitutes 'regular' programming
* It is commonly attributed to [[KDKA (AM)|KDKA]] in [[Pittsburgh]], [[Pennsylvania]], which in October 1920 received its license and went on the air as the first US licensed commercial broadcasting station on November 2, 1920, with the presidential election results as its inaugural show, but was not broadcasting daily until 1921. (Their engineer [[Frank Conrad]] had been broadcasting from on the two call sign signals of 8XK and 8YK since 1916.) Technically, KDKA was the first of several already-extant stations to receive a 'limited commercial' license.<ref>{{Cite web|title=The Pennsylvania Center for the Book – KDKA|url=http://pabook2.libraries.psu.edu/palitmap/KDKA.html|website=pabook2.libraries.psu.edu|access-date=2020-05-28|archive-date=2020-08-01|archive-url=https://web.archive.org/web/20200801143557/http://pabook2.libraries.psu.edu/palitmap/KDKA.html|url-status=dead}}</ref>
* On February 17, 1919, station 9XM at the [[University of Wisconsin–Madison|University of Wisconsin]] in [[Madison, Wisconsin|Madison]] broadcast human speech to the public at large. 9XM was first experimentally licensed in 1914, began regular [[Morse code]] transmissions in 1916, and its first music broadcast in 1917. Regularly scheduled broadcasts of voice and music began in January 1921. That station is still on the air today as [[WHA (AM)|WHA]].<ref>{{Cite book|last=Sterling|first=Christopher|title=The Concise Encyclopedia of American Radio|publisher=Sterling|year=2009|isbn=978-0415995337|page=847}}</ref>
* On August 20, 1920, 8MK, began broadcasting daily and was later claimed by famed inventor [[Lee de Forest]] as the first commercial station. 8MK was licensed to a teenager, Michael DeLisle Lyons, and financed by [[E. W. Scripps]]. In 1921 8MK changed to WBL and then to [[WWJ (AM)|WWJ]] in 1922, in [[Detroit]]. It has carried a regular schedule of programming to the present and also broadcast the 1920 presidential election returns just as KDKA did.<ref>''A Tower in Babel'' by Eric Barnouw, 1966, pp. 62–64</ref>  Inventor Lee de Forest claims to have been present during 8MK's earliest broadcasts, since the station was using a transmitter sold by his company.<ref>Larry Wolters, "Radio Illusions Dispelled By DeForest."  ''Chicago Tribune'', 13 September 1936, p. SW 7</ref>
* The first station to receive a commercial license was [[WBZ (AM)|WBZ]], then in [[Springfield, Massachusetts]].  Lists provided to the ''[[Boston Globe]]'' by the [[U.S. Department of Commerce]] showed that WBZ received its commercial license on 15 September 1921; another Westinghouse station, [[WABC (AM)|WJZ]], then in [[Newark, New Jersey]], received its commercial license on November 7, the same day as KDKA did.<ref>"Radio's Anniversary," ''Boston Globe'', 30 September 1928, p. B27.</ref> What separates WJZ and WBZ from KDKA is the fact that neither of the former stations remain in their original city of license, whereas KDKA has remained in Pittsburgh for its entire existence.
* [[2XG]]: Launched by Lee de Forest in the [[High Bridge (New York City)|Highbridge]] section of New York City, that station began daily broadcasts in 1916.<ref>{{cite web|title=Highbridge Station Reports (1917)|url=https://earlyradiohistory.us/1917df.htm|work=earlyradiohistory.us}}</ref> Like most experimental radio stations, however, it had to go off the air when the U.S. entered World War I in 1917, and did not return to the air.
* [[WGI (radio station)|1XE]]: Launched by Harold J. Power in [[Medford, Massachusetts]], 1XE was an experimental station that started broadcasting in 1917. It had to go off the air during World War I, but started up again after the war, and began regular voice and music broadcasts in 1919.  However, the station did not receive its commercial license, becoming [[WGI (radio station)|WGI]], until 1922.<ref>{{cite web|title=The Rise and Fall of WGI|url=http://www.bostonradio.org/essays/wgi.html|author=Donna L. Halper|date=2001-01-02|work=The Boston Radio Archives (bostonradio.org)}}</ref>
* [[WWV (radio station)|WWV]], the U.S. Government time service, which was believed to have started 6 months before KDKA in Washington, D.C. but in 1966 was transferred to Ft. Collins, Colorado.<ref>{{Cite journal|title=NIST Time and Frequency Division History|url=https://www.nist.gov/pml/time-and-frequency-division/time-services/nist-time-and-frequency-division-history|last=lombardi|date=2010-05-11|journal=NIST|language=en|access-date=2020-05-28}}</ref>
* [[WRUC]], the Wireless Radio Union College, located on [[Union College]] in [[Schenectady, New York]]; was launched as W2XQ <ref>{{Cite web|url=https://libguides.union.edu/ArchivesandSpecialCollections/WRUC|title=Subject Research, Course Guides, Documentation: Archives & Special Collections: WRUC (Union College Radio Station)|first=Sarah|last=Schmidt|website=libguides.union.edu|access-date=2020-05-28|archive-date=2020-08-01|archive-url=https://web.archive.org/web/20200801143726/https://libguides.union.edu/ArchivesandSpecialCollections/WRUC|url-status=dead}}</ref>
* [[KQV]], one of Pittsburgh's five original AM stations, signed on as amateur station "8ZAE" on November 19, 1919, but did not receive a commercial license until January 9, 1922.

== See also ==
* [[History of electrical engineering]]
* [[History of electromagnetic theory]]
* [[History of amateur radio]]
* [[History of broadcasting]]
* [[History of podcasting]]
* [[History of radar]]
* [[History of radio receivers]]
* [[History of telecommunication]]
* [[History of television]]
* [[A.S. Popov Central Museum of Communications]]
* [[Digital audio broadcasting]] (DAB)
* [[Internet radio]]
* [[Spark-gap transmitter]]
* [[Timeline of the introduction of radio in countries]]
* [[Wireless]]
* [[Wireless LAN]]s

== Footnotes ==

{{Reflist}}

== References ==

=== Primary sources ===
{{Refbegin|2}}
* De Lee Forest. ''Father of Radio: The Autobiography of Lee de Forest'' (1950).
* Gleason L. Archer Personal Papers (MS108), Suffolk University Archives, Suffolk University; Boston, Massachusetts. [https://web.archive.org/web/20080529075535/http://www.suffolk.edu/files/Archives/MS108_findaid.pdf Gleason L. Archer Personal Papers (MS108) finding aid]
* Kahn Frank J., ed. ''Documents of American Broadcasting,'' fourth edition (Prentice-Hall, Inc., 1984).
* Lichty Lawrence W., and Topping Malachi C., eds. ''American Broadcasting: A Source Book on the History of Radio and Television'' (Hastings House, 1975).
{{Refend}}

===Secondary sources===

{{Refbegin|2}}
* Aitkin, Hugh G. J. ''The Continuous Wave: Technology and the American Radio, 1900–1932'' (Princeton University Press, 1985).
* Anderson, Leland. "''Nikola Tesla On His Work With Alternating Currents and Their Application to Wireless Telegraphy, Telephony, and Transmission of Power''", Sun Publishing Company, LC {{not a typo|92-60482}}, {{ISBN|0963265202}} (''ed''. [http://www.tfcbooks.com/tesla/nt_on_ac.htm excerpts available online])
* Anderson, Leland I. ''Priority in the Invention of Radio – [http://www.tfcbooks.com/mall/more/431pir.htm Tesla vs. Marconi]'', Antique Wireless Association monograph, 1980, examining the 1943 decision by the [[US Supreme Court]] holding the key Marconi patent invalid (9 pages). (21st Century Books)
* Archer, Gleason L. Big Business and Radio (The American Historical Society, Inc., 1939)
* Archer, Gleason L. History of Radio to 1926 (The American Historical Society, Inc., 1938).
* Barnouw, Erik. ''The Golden Web'' (Oxford University Press, 1968); ''The Sponsor'' (1978); ''A Tower in Babel'' (1966).
* Belrose, John S., "''[http://www.ieee.ca/millennium/radio/radio_differences.html Fessenden and Marconi: Their Differing Technologies and Transatlantic Experiments During the First Decade of this Century]''". International Conference on 100 Years of Radio (5–7 September 1995).
* Briggs, Asa. ''The BBC – the First Fifty Years'' (Oxford University Press, 1984).
* Briggs, Asa. ''The History of Broadcasting in the United Kingdom'' (Oxford University Press, 1961).
* Brodsky, Ira. "The History of Wireless: How Creative Minds Produced Technology for the Masses" (Telescope Books, 2008)
* Butler, Lloyd (VK5BR), "''[http://www.qsl.net/vk5br/Before_Valve_Amp.pdf Before Valve Amplification] {{Webarchive|url=https://web.archive.org/web/20200808105830/http://www.qsl.net/vk5br/Before_Valve_Amp.pdf |date=2020-08-08 }} – Wireless Communication of an Early Era''"
* Coe, Douglas and Kreigh Collins (ills), "''Marconi, pioneer of radio''". New York, J. Messner, Inc., 1943. {{LCCN|43010048}}
* Covert, Cathy and Stevens John L. ''Mass Media Between the Wars'' (Syracuse University Press, 1984).
* Craig, Douglas B. ''Fireside Politics: Radio and Political Culture in the United States, 1920–1940'' (2005)
* Crook, Tim. ''International Radio Journalism: History, Theory and Practice'' Routledge, 1998
* Douglas, Susan J., ''Listening in : radio and the American imagination : from Amos 'n' Andy and Edward R. Murrow to Wolfman Jack and Howard Stern '', New York: Times Books, 1999.
* Ewbank Henry and Lawton Sherman P. ''Broadcasting: Radio and Television'' (Harper & Brothers, 1952).
* Garratt, G. R. M., "''The early history of radio : from Faraday to Marconi''", London, Institution of Electrical Engineers in association with the Science Museum, History of technology series, 1994. {{ISBN|0852968450}} {{LCCN|94011611}}
* Geddes, Keith, "''Guglielmo Marconi, 1874–1937''". London : H.M.S.O., A Science Museum booklet, 1974. {{ISBN|0112901980}} {{LCCN|75329825}} (''ed''. Obtainable in the US from Pendragon House Inc., Palo Alto, California.)
* Gibson, George H. ''Public Broadcasting; The Role of the Federal Government, 1919–1976'' (Praeger Publishers, 1977).
* Hancock, Harry Edgar, "''Wireless at sea; the first fifty years. A history of the progress and development of marine wireless communications written to commemorate the jubilee of the Marconi International Marine Communication Company limited''". Chelmsford, Eng., Marconi International Marine Communication Co., 1950. {{LCCN|51040529}}
* Jackaway, Gwenyth L. ''Media at War: Radio's Challenge to the Newspapers, 1924–1939'' Praeger Publishers, 1995
* Journal of the Franklin Institute. "''[https://babel.hathitrust.org/cgi/pt?id=uc1.$b569540&view=1up&seq=493 Notes and comments; Telegraphy without wires]''", Journal of the Franklin Institute, December 1897, pp.&nbsp;463–64.
* Katz, Randy H., "''[http://www.cs.berkeley.edu/~randy/Courses/CS39C.S97/radio/radio.html Look Ma, No Wires": Marconi and the Invention of Radio]''". History of Communications Infrastructures.
* Lazarsfeld, Paul F. ''The People Look at Radio'' (University of North Carolina Press, 1946).
* Maclaurin, W. Rupert. ''Invention and Innovation in the Radio Industry'' (The Macmillan Company, 1949).
* Marconi's Wireless Telegraph Company, "''Year book of wireless telegraphy and telephony''", London : Published for the Marconi Press Agency Ltd., by the St. Catherine Press / Wireless Press. {{LCCN|14017875}} {{LCCN|86035439}}
* Marincic, Aleksandar and Djuradj Budimir, "''[https://web.archive.org/web/20080529075537/http://www.mwr.medianis.net/pdf/Vol7No2-05-AMarincic.pdf Tesla contribution to radio wave propagation]''". ([[PDF]])
* Masini, Giancarlo. "''Guglielmo Marconi''". Turin: Turinese typographical-publishing union, 1975. {{LCCN|77472455}} (''ed. Contains 32 tables outside of the text'')
* Massie, Walter Wentworth, "''Wireless telegraphy and telephony popularly explained''". New York, Van Nostrand, 1908.
* McChesney, Robert W. ''Telecommunications, Mass Media, and Democracy: The Battle for the Control of U.S. Broadcasting, 1928–1935'' Oxford University Press, 1994
* McCourt, Tom. ''Conflicting Communication Interests in America: The Case of National Public Radio'' Praeger Publishers, 1999
* McNicol, Donald. "''[https://archive.org/details/electricalexperi04gern/page/893/mode/1up The Early Days of Radio in America]''". [[The Electrical Experimenter]], April 1917, pp.&nbsp;893, 911.
* Peers, Frank W. ''The Politics of Canadian Broadcasting, 1920–1951'' (University of Toronto Press, 1969).
* Pimsleur, J. L. "''[http://www.sfmuseum.org/hist/radio.html Invention of Radio Celebrated in S.F.]; 100th birthday exhibit this weekend ''". San Francisco Chronicle, 1995.
* ''The Prestige'', 2006, Touchstone Pictures.
* The Radio Staff of the Detroit News, ''WWJ-The Detroit News'' (The Evening News Association, Detroit, 1922).
* Ray, William B. ''FCC: The Ups and Downs of Radio-TV Regulation'' (Iowa State University Press, 1990).
* Rosen, Philip T. ''The Modern Stentors; Radio Broadcasting and the Federal Government 1920–1934'' (Greenwood Press, 1980).
** Rugh, William A. ''Arab Mass Media: Newspapers, Radio, and Television in Arab Politics'' Praeger, 2004
* Scannell, Paddy, and Cardiff, David. ''A Social History of British Broadcasting, Volume One, 1922–1939'' (Basil Blackwell, 1991).
* Schramm Wilbur, ed. ''Mass Communications'' (University of Illinois Press, 1960).
* Schwoch James. ''The American Radio Industry and Its Latin American Activities, 1900–1939'' (University of Illinois Press, 1990).
* Seifer, Marc J., "''The Secret History of Wireless''". Kingston, Rhode Island.
* Slater, Robert. ''This ... is CBS: A Chronicle of 60 Years'' (Prentice Hall, 1988).
* Smith, F. Leslie, John W. Wright II, David H. Ostroff; ''Perspectives on Radio and Television: Telecommunication in the United States'' Lawrence Erlbaum Associates, 1998
* Sterling, Christopher H. ''Electronic Media, A Guide to Trends in Broadcasting and Newer Technologies 1920–1983'' (Praeger, 1984).
* Sterling, Christopher, and Kittross John M. ''Stay Tuned: A Concise History of American Broadcasting'' (Wadsworth, 1978).
* [[John Stone Stone|Stone, John Stone]]. "John Stone Stone on Nikola Tesla's Priority in Radio and Continuous-Wave Radiofrequency Apparatus". [http://www.tfcbooks.com/mall/more/436ntpr.htm Twenty First Century Books, 2005].
* Sungook Hong, "''Wireless: from Marconi's Black-box to the Audion''", Cambridge, Massachusetts: MIT Press, 2001, {{ISBN|0262082985}}
* Waldron, Richard Arthur, "''Theory of guided electromagnetic waves''". London, New York, Van Nostrand Reinhold, 1970. {{ISBN|0442091672}} {{LCCN|69019848}}
* Weightman, Gavin, "''Signor Marconi's magic box : the most remarkable invention of the 19th century & the amateur inventor whose genius sparked a revolution''" 1st Da Capo Press ed., Cambridge, Massachusetts : Da Capo Press, 2003.
* White, Llewellyn. ''The American Radio'' (University of Chicago Press, 1947).
* White, Thomas H. "''[https://earlyradiohistory.us/sec007.htm Pioneering U.S. Radio Activities (1897–1917)]''", United States Early Radio History.
* Wunsch, A. David "''[http://www.mercurians.org/1998_Fall/Misreading.htm Misreading the Supreme Court: A Puzzling Chapter in the History of Radio]''" Mercurians.org.
{{Refend}}

== Media and documentaries ==
* ''[[Empire of the Air: The Men Who Made Radio]]'' (1992) by [[Ken Burns]], PBS documentary based on the 1991 book, ''Empire of the Air: The Men Who Made Radio'' by Tom Lewis, 1st ed., New York : E. Burlingame Books, {{ISBN|0060182156}}

== External links ==
{{Commons category|History of radio}}

{{Refbegin}}
* "''[http://www.tfcbooks.com/teslafaq/q&a_038.htm A Comparison of the Tesla and Marconi Low-Frequency Wireless Systems] ''". Twenty First Century Books, Breckenridge, Co.
* [http://www.zianet.com/sparks/sparkmakers2.html Sparks Telegraph Key Review]
* "[http://www.lostartsmedia.com/nikolatesla.html Presentation of the Edison Medal to Nikola Tesla]". Minutes of the Annual Meeting of the American Institute of Electrical Engineers. Held at the Engineering Society Building, New York City, Friday evening, May 18, 1917.
* ''[http://ns1763.ca/radio30/radio-first-30yrs.html Timeline of the First Thirty Years of Radio 1895–1925] {{Webarchive|url=https://web.archive.org/web/20080331093640/http://ns1763.ca/radio30/radio-first-30yrs.html |date=2008-03-31 }}; An important chapter in the Death of Distance''. Nova Scotia, Canada, March 14, 2006.
* [http://www.cybertelecom.org/notes/history_wireless.htm Cybertelecom :: Radio History (legal and regulatory)] {{Webarchive|url=https://web.archive.org/web/20230418122217/http://www.cybertelecom.org/notes/history_wireless.htm |date=2023-04-18 }}
* [http://www.radioblvd.com/ Western Historic Radio Museum: Radio Communication Equipment from 1909 to 1959.]
{{Refend}}

{{Audio broadcasting}}
{{Morse code}}
{{Telecommunications}}
{{Authority control}}

{{DEFAULTSORT:History Of Radio}}
[[Category:History of radio| ]]
[[Category:Guglielmo Marconi]]
[[Category:History of technology|Radio]]