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History of radio - Wikipedia, the free encyclopedia

History of radio

From Wikipedia, the free encyclopedia

The pre-history and early history of radio is the history of technology that produced instruments that use radio waves. Later radio history increasingly involves matters of programming and content.

Various scientists proposed that electricity and magnetism, both capable of causing attraction and repulsion of objects, were linked. In 1802 Gian Domenico Romagnosi suggested the relationship between electric current and magnetism, but his reports went unnoticed. In 1820 Hans Christian Ørsted performed a widely known experiment on man-made electric current and magnetism. He demonstrated that a wire carrying a current could deflect a magnetized compass needle. Ørsted's experiments discovered the relationship between electricity and magnetism in a very simple experiment. Ørsted's work influenced André-Marie Ampère to produce a theory of electromagnetism. In the history of radio and development of "wireless telegraphy", several people are claimed to have "invented the radio". The most commonly accepted claims are:

Contents

[edit] Wireless prehistory (19th century)

In the late 19th century it was clear to various scientists and experimenters that wireless communication was possible. Various theoretical and experimental innovations led to the development of radio and the communication system we know today. Some early work was done by local effects and experiments of electromagnetic induction. Many understood that there was nothing similar to the "ethereal telegraphy" [1][2] and telegraphy by induction; the phenomena being wholly distinct. Wireless telegraphy was beginning to take hold and the practice of transmitting messages without wires was being developed. Many people worked on developing the devices and improvements.

[edit] Faraday

In 1831, Michael Faraday began a series of experiments in which he discovered electromagnetic induction. The relation was mathematically modelled by Faraday's law, which subsequently became one of the four Maxwell equations. Faraday proposed that electromagnetic forces extended into the empty space around the conductor, but did not complete his work involving that proposal.

James Clerk Maxwell was an experimenter with electromagnetic waves and developed the Maxwell equations.
James Clerk Maxwell was an experimenter with electromagnetic waves and developed the Maxwell equations.

[edit] William Henry Ward

In April 1872 William Henry Ward received U.S. Patent 126,356  for radio development.

[edit] Maxwell

Between 1861 and 1865, James Clerk Maxwell made experiments with electromagnetic waves. In 1873, as a result of experiments, Maxwell first described the theoretical basis of the propagation of electromagnetic waves in his paper to the Royal Society, "A Dynamical Theory of the Electromagnetic Field."

[edit] Mahlon Loomis

Mahlon Loomis of West Virginia has the oldest and most documented claim of inventing radio. Loomis received U.S. Patent 129,971  for a "wireless telegraph" in July 1872. This patent utilizes atmospheric electricity to eliminate the overhead wire used by the existing telegraph systems. It did not contain diagrams or specific methods. It is substantially similar to William Henry Ward's patent.

[edit] Edison (1875)

Towards the end of 1875, while experimenting with the telegraph, Thomas Edison noted a phenomenon that he termed "etheric force", announcing it to the press on November 28. He abandoned this research when Elihu Thomson, among others, ridiculed the idea.

[edit] David E. Hughes

In 1878, David E. Hughes was the first to transmit and receive radio waves when he noticed that his induction balance caused noise in the receiver of his homemade telephone. He demonstrated his discovery to the Royal Society in 1880 but was told it was merely induction.

[edit] Calzecchi-Onesti

In 1884, Temistocle Calzecchi-Onesti at Fermo in Italy invented a primitive device that responded to radio waves. It consisted of a tube filled with iron filings, called a "coherer". This device was a critical discovery because it would later be developed to become the first practical radio detector.

[edit] Edouard Branly

Between 1884 and 1886, Edouard Branly of France produced an improved version of the coherer.

[edit] Edison (1885)

In 1885, Edison took out U.S. Patent 465,971  on a system of radio communication between ships (which later he sold to Marconi).

[edit] Hertz

Between 1886 and 1888, Heinrich Rudolf Hertz validated Maxwell's theory through experiment. He demonstrated that radio radiation had all the properties of waves (now called Hertzian waves), and discovered that the electromagnetic equations could be reformulated into a partial differential equation called the wave equation. But he saw no practical use for his discovery. For more information see Hertz's radio work.

[edit] Stubblefield

Claims have been made that Murray, Kentucky farmer Nathan Stubblefield invented radio between 1885 and 1892, before either Tesla or Marconi, but his devices seemed to have worked by induction transmission rather than radio transmission.

[edit] Landell de Moura

Between 1893 and 1894, Roberto Landell de Moura, a Brazilian priest and scientist, conducted experiments in wireless transmissions. He did not publicize his achievement until 1900, when he held a public demonstration of a wireless transmission of voice in São Paulo, Brazil on June 3.

[edit] Beginnings of radio

There are varying disputed claims about who invented radio, which in the beginning was called "wireless telegraphy". The key invention for the beginning of "wireless transmission of data using the entire frequency spectrum", known as the spark-gap transmitter, has been attributed to various men. Marconi equipped ships with lifesaving wireless communications and established the first transatlantic radio service. Tesla developed means to reliably produce radio frequency electrical currents, publicly demonstrated the principles of radio, and transmitted long distance signals.

Nikola Tesla developed means to reliably produce radio frequencies, publicly demonstrated the principles of radio, and transmitted long distant signals. He holds the US patent for the invention of the radio, as defined as "wireless transmission of data".
Nikola Tesla developed means to reliably produce radio frequencies, publicly demonstrated the principles of radio, and transmitted long distant signals. He holds the US patent for the invention of the radio, as defined as "wireless transmission of data".

[edit] Nikola Tesla

In 1891 Tesla began his research into radio. He later published an article, "The True Wireless", concerning this research.[3] In 1892 he gave a lecture called "Experiments with Alternate Currents of High Potential and High Frequency", in London (Available at Project Gutenberg).[4] In 1893, at St. Louis, Missouri, Tesla gave a public demonstration of "wireless" radio communication. Addressing the Franklin Institute in Philadelphia and the National Electric Light Association, he described in detail the principles of radio communication.[5] The apparatus that Tesla used contained all the elements that were incorporated into radio systems before the development of the "oscillation valve", the early vacuum tube.

Tesla was the first to apply the mechanism of electrical conduction to wireless practices. Also, he initially used sensitive electromagnetic receivers,[6] that were unlike the less responsive coherers later used by Marconi and other early experimenters. Afterwards, the principle of radio communication (sending signals through space to receivers) was publicized widely. Various scientists, inventors, and experimenters began to investigate wireless methods. He was re-awarded the patent rights, after holding them initially, for radio by the United States Supreme Court after his death in 1943. For more information see Tesla's wireless work.

[edit] Oliver Lodge

Oliver Lodge transmitted radio signals on August 14, 1894 (one year after Tesla, five years after Heinrich Hertz and one year before Marconi) at a meeting of the British Association for the Advancement of Science at Oxford University.[7] (In 1995, the Royal Society recognized this scientific breakthrough at a special ceremony at Oxford University. For more information, see Past Years: An Autobiography, New York: Charles Scribner's Sons, p231.)

On 19 August 1894 Lodge demonstrated the reception of Morse code signalling via radio waves using a "coherer". He improved Edouard Branly's coherer radio wave detector by adding a "trembler" which dislodged clumped filings, thus restoring the device's sensitivity. [8] In August 1898 he got U.S. Patent 609,154 , "Electric Telegraphy", that made wireless signals using Ruhmkorff coils or Tesla coils for the transmitter and a Branly coherer for the detector. This was key to the "syntonic" tuning concept. In 1912 Lodge sold the patent to Marconi.

[edit] Jagdish Chandra Bose

In November 1894, the Bengali Indian physicist, Jagdish Chandra Bose, demonstrated publicly the use of radio waves in Calcutta, but he was not interested in patenting his work.[9] Bose ignited gunpowder and rang a bell at a distance using electromagnetic waves, proving that communication signals can be sent without using wires.

The 1895 public demonstration by Bose in Calcutta was before Marconi's wireless signalling experiment on Salisbury Plain in England in May 1897.[10][11]

In 1896, the Daily Chronicle of England reported on his UHF experiments: "The inventor (J.C. Bose) has transmitted signals to a distance of nearly a mile and herein lies the first and obvious and exceedingly valuable application of this new theoretical marvel."

[edit] Alexander Popov

Popov was the first man to demonstrate the practical applications of radio waves.
Popov was the first man to demonstrate the practical applications of radio waves.

In 1895, the Russian physicist Alexander Popov built a coherer. On May 7, 1895, Popov performed a public demonstration of transmission and reception of radio waves used for communication at the Russian Physical and Chemical Society, using his coherer:[12] this day has since been celebrated in Russia as "Radio Day". He did not apply for a patent for this invention. Popov's early experiments were transmissions of only 600 yards. Popov was the first to develop a practical communication system based on the coherer, and is usually considered by the Russians to have been the inventor of radio.[13][14]

Around March 1896 Popov demonstrated in public the transmission of radio waves, between different campus buildings, to the Saint Petersburg Physical Society. (This was before the public demonstration of the Marconi system around September 1896). Per other accounts, however, Popov achieved these results only in December, 1897; that is, after publication of Marconi's patent.[15] In 1898 his signal was received 6 miles away, and in 1899 30 miles away. In 1900, Popov stated at the Congress of Russian Electrical Engineers that,

"the emission and reception of signals by Marconi by means of electric oscillations was nothing new, as in America Nikola Tesla did the same experiments in 1893."[16][17]

Later Popov experimented with ship-to-shore communication. Popov died in 1905 and his claim was not pressed by the Russian government until 1945.

[edit] Around 1895: 3-way near photofinish for first use of radio

  • In February 1893, Tesla delivers "On Light and Other High Frequency Phenomena" before the Franklin Institute in Philadelphia.
  • In 1895, Marconi receives a telegraph message without wires a short distance (below a mile), but he did not send his voice over the airwaves. In March 1895, Popov transmitted radio waves between campus buildings in Saint Petersburg, but did not apply for a patent.
  • In 1896, Tesla detected transmissions from his New York lab of low frequency (50,000 cycle per second) undamped waves with a receiver located at West Point, "a distance of about 30 miles." [18]

[edit] Ernest Rutherford

The New Zealander Ernest Rutherford, 1st Baron Rutherford of Nelson was instrumental in the development of radio. In 1895 he was awarded an Exhibition of 1851 Science Research Scholarship to Cambridge. He arrived in England with a reputation as an innovator and inventor, and distinguished himself in several fields, initially by working out the electrical properties of solids and then using wireless waves as a method of signalling. Rutherford was encouraged in his work by Sir Robert Ball, who had been scientific adviser to the body maintaining lighthouses on the Irish coast; he wished to solve the difficult problem of a ship’s inability to detect a lighthouse in fog. Sensing fame and fortune, Rutherford increased the sensitivity of his apparatus until he could detect electromagnetic waves over a distance of several hundred meters. The commercial development, though, of wireless technology was left for others, as Rutherford continued purely scientific research. Thomson quickly realised that Rutherford was a researcher of exceptional ability and invited him to join in a study of the electrical conduction of gases.

[edit] Marconi

Guglielmo Marconi was an electrical engineer and Nobel laureate known for the development of a practical wireless telegraphy system.
Guglielmo Marconi was an electrical engineer and Nobel laureate known for the development of a practical wireless telegraphy system.

In 1896, Guglielmo Marconi was awarded a patent for radio with British Patent 12039, Improvements in Transmitting Electrical Impulses and Signals and in Apparatus There-for. This was the initial patent for the radio, though it used various earlier techniques of various other experimenters (primarily Tesla) and resembled the instrument demonstrated by others (including Popov). During this time spark-gap wireless telegraphy was widely researched.

In 1896, Bose went to London on a lecture tour and met Marconi, who was conducting wireless experiments for the British post office. In 1897, Marconi established the radio station at Niton, Isle of Wight, England. In 1897, Tesla applied for two key radio patents in the USA. Those two patents were issued in early 1900. In 1898, Marconi opened a radio factory in Hall Street, Chelmsford, England, employing around 50 people. In 1899, Bose announced his invention of the "iron-mercury-iron coherer with telephone detector" in a paper presented at Royal Society, London.

[edit] Julio Cervera Baviera

Julio Cervera Baviera
Julio Cervera Baviera

Recent studies in Spain credit Julio Cervera Baviera as the inventor of the radio (in 1902).[19] [20] Cervera Baviera obtained patents in England, Germany, Belgium, and Spain. In May-June 1899, Cervera had, with the blessing of the Spanish Army, visited Marconi's radiotelegraphic installations on the English Channel, and worked to develop his own system. He began collaborating with Marconi on resolving the problem of a wireless communication system, obtaining some patents by the end of 1899. Cervera, who had worked with Marconi and his assistant George Kemp in 1899, resolved the difficulties of wireless telegraph and obtained his first patents prior to the end of that year. On March 22, 1902, Cervera founded the Spanish Wireless Telegraph and Telephone Corporation and brought to his corporation the patents he had obtained in Spain, Belgium, Germany and England.[21] He established the second and third regular radiotelegraph service in the history of the world in 1901 and 1902 by maintaining regular transmissions between Tarifa and Ceuta for three consecutive months, and between Javea (Cabo de la Nao) and Ibiza (Cabo Pelado). This is after Marconi established the radiotelegraphic service between the Isle of Wight and Bournemouth in 1898. In 1906, Domenico Mazzotto wrote: "In Spain the Minister of War has applied the system perfected by the commander of military engineering, Julio Cervera Baviera (English patent No. 20084 (1899))."[22] Cervera thus achieved some success in this field, but his radiotelegraphic activities ceased suddenly, the reasons for which are unclear to this day.[23]

[edit] Turn of the century

Around the turn of the century, the Slaby-Arco wireless system was developed by Adolf Slaby and Georg von Arco (later incorporated into Telefunken). In 1900, Reginald Fessenden made a weak transmission of voice over the airwaves. Around 1900, Tesla opened the Wardenclyffe Tower facility and advertised services. In 1901, Marconi conducted the first successful transatlantic experimental radio communications. In 1903, Wardenclyffe Tower neared completion. Various theories exist on how Tesla intended to achieve the goals of this wireless system (reportedly, a 200 kW system). Tesla claimed that Wardenclyffe, as part of a World System of transmitters, would have allowed secure multichannel transceiving of information, universal navigation, time synchronization, and a global location system.

In 1904, The U.S. Patent Office reversed its decision, awarding Marconi a patent for the invention of radio, possibly influenced by Marconi's financial backers in the States, who included Thomas Edison and Andrew Carnegie. This also allowed the U.S. government (among others) to avoid having to pay the royalties that were being claimed by Tesla for use of his patents. For more information see Marconi's radio work. In 1907, Marconi established the first commercial transatlantic radio communications service, between Clifden, Ireland and Glace Bay, Newfoundland.

[edit] Early radio telegraphy and telephony

Donald Manson working as an employee of the Marconi Company (England, 1906)
Donald Manson working as an employee of the Marconi Company (England, 1906)

[edit] British Marconi

Using various patents, the company called British Marconi was established and began communication between coast radio stations and ships at sea. This company along with its subsidiary American Marconi, had a stranglehold on ship to shore communication. It operated much the way 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 the first seeds of broadcasting were planted.

[edit] Reginald Fessenden

The invention of amplitude-modulated (AM) radio, so that more than one station can send signals (as opposed to spark-gap radio, where one transmitter covers the entire bandwidth of the spectrum) is attributed to Reginald Fessenden and Lee de Forest. On Christmas Eve 1906, Reginald Fessenden used an Alexanderson alternator and rotary spark-gap transmitter to make the first radio audio broadcast, from 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.

[edit] Karl Braun

In 1909, Marconi and Karl Ferdinand Braun were awarded the Nobel Prize in Physics for "contributions to the development of wireless telegraphy".

[edit] Charles David Herrold

In April 1909 Charles David Herrold, an electronics instructor in San Jose, California constructed a broadcasting station. It used spark gap technology, but modulated the carrier frequency with the human voice, and later music. The station "San Jose Calling" (there were no call letters), continued to eventually become today's KCBS in San Francisco. Herrold, the son of a Santa Clara Valley farmer, coined the terms "narrowcasting" and "broadcasting", respectively to identify transmissions destined for a single receiver such as that on board a ship, and those transmissions destined for a general audience. (The term "broadcasting" had been used in farming to define the tossing of seed in all directions.) Charles Herrold did not claim to be the first to transmit the human voice, but he claimed to be the first to conduct "broadcasting". To help the radio signal to spread in all directions, he designed some omnidirectional antennas, which he mounted on the rooftops of various buildings in San Jose. Herrold also claims to be the first broadcaster to accept advertising (he exchanged publicity for a local record store for records to play on his station), though this dubious honour usually is foisted on WEAF (1922).

RMS Titanic (April 2, 1912).
RMS Titanic (April 2, 1912).

In 1912, the RMS Titanic sank in the northern Atlantic Ocean. After this, wireless telegraphy using spark-gap transmitters quickly became universal on large ships. In 1913, the International Convention for the Safety of Life at Sea was convened and produced a treaty requiring shipboard radio stations to be manned 24 hours a day. A typical high-power spark gap was a rotating commutator with six to twelve contacts per wheel, nine inches to a foot wide, driven by about 2000 volts DC. As the gaps made and broke contact, the radio wave was audible as a tone in a crystal set. The telegraph key often directly made and broke the 2000 volt supply. One side of the spark gap was directly connected to the antenna. Receivers with thermionic valves became commonplace before spark-gap transmitters were replaced by continuous wave transmitters.

[edit] Harold J. Power

On March 8, 1916, Harold Power with his radio company American Radio and Research Company (AMRAD), broadcast the first continuous broadcast in the world from Tufts University under the call sign 1XE (it lasted 3 hours). The company later became the first to broadcast on a daily schedule, and the first to broadcast radio dance programs, university professor lectures, the weather, and bedtime stories [24].

[edit] Other innovators

Many scientists and inventors contributed to the invention of wireless telegraphy and telephony. Individuals that helped to further the science include, among others:

[edit] Audio broadcasting (1919 to 1950s)

See also: Old-time radio

[edit] Crystal sets

The most common type of receiver before vacuum tubes was the 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 enabled audio radio. The use of amplitude modulation (AM), with which more than one station can simultaneously send signals (as opposed to spark-gap radio, where one transmitter covers the entire bandwidth of spectra) was pioneered by Fessenden and Lee de Forest.

To this day there is a small but avid base of fans of this technology who study and practice the art and science of designing and making crystal sets as a hobby; the Boy Scouts of America have often undertaken such craft projects to introduce boys to electronics and radio, and quite a number of them having grown up remain staunch fans of a radio that 'runs on nothing, forever'. As the only energy available is that gathered by the antenna system, there are inherent limitations on how much sound even an ideal set could produce, but with only moderately decent antenna systems remarkable performance is possible with a superior set.

[edit] The first vacuum tubes

During the mid 1920s, amplifying vacuum tubes (or thermionic valves in the UK) revolutionized radio receivers and transmitters. John Ambrose Fleming developed an earlier tube known as an "oscillation valve" (it was a diode). Lee De Forest placed a screen, the "grid" electrode, between the filament and plate electrode. The Dutch engineer Hanso Schotanus à Steringa Idzerda made the first regular wireless broadcast for entertainment from his home in The Hague on 6 November 1919. He broadcast his popular program four nights per week until 1924 when he ran into financial troubles.

On 27 August 1920, regular wireless broadcasts for entertainment began in Argentina, pioneered by the group around Enrique Telémaco Susini, and spark gap telegraphy stopped. On 31 August 1920 the first known radio news program was broadcast by station 8MK, the unlicensed predecessor of WWJ (AM) in Detroit, Michigan. In 1922 regular wireless broadcasts for entertainment began in the UK from the Marconi Research Centre 2MT at Writtle near Chelmsford, England. Early radios ran the entire power of the transmitter through a carbon microphone. In the 1920s, the Westinghouse company bought Lee De Forest's and Edwin Armstrong's patent. During the mid 1920s, Amplifying vacuum tubes (US)/thermionic valves (UK) revolutionized radio receivers and transmitters. Westinghouse engineers developed a more modern vacuum tube.

[edit] Licensed commercial public radio stations

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 in Pittsburgh, Pennsylvania, which in October 1920 received its license and went on the air as the first US licensed commercial broadcasting station. (Their engineer Frank Conrad had been broadcasting from his own station since 1916.) Technically, KDKA was the first of several already-extant stations to receive a 'limited commercial' license.
  • On February 17, 1919, station 9XM at the University of Wisconsin in Madison had already broadcast the first human speech to the public at large. That station is still on the air today as WHA.
  • 9XM sent music over the air two years earlier, was originally licensed in 1914 and sent its first transmission in 1916.
  • On August 20, 1920, at least two months before KDKA, E.W. Scripps's WBL (now WWJ) in Detroit started broadcasting. It has carried a regular schedule of programming to the present.
  • There is the history noted above of Charles David Herrold's radio services (eventually KCBS) going back to 1909.

Broadcasting was not yet supported by advertising or listener sponsorship. The stations owned by manufacturers and department stores were established to sell radios and those owned by newspapers to sell newspapers and express the opinions of the owners. In the 1920s, Radio was first used to transmit pictures visible as television. During the early 1930s, single sideband (SSB) and frequency modulation (FM) were invented by amateur radio operators. By 1940, they were established commercial modes.

Westinghouse was brought into the patent allies group, General Electric, American Telephone and Telegraph, and Radio Corporation of America, and became a part owner of RCA. All radios made by GE and Westinghouse were sold under the RCA label 60% GE and 40% Westinghouse. ATT's Western Electric would build radio transmitters. The patent allies attempted to set up a monopoly, but they failed due to successful competition. Much to the dismay of the patent allies, several of the contracts for inventor's patents held clauses protecting "amateurs" and allowing them to use the patents. Whether the competing manufacturers were really amateurs was ignored by these competitors.

These features arose:

[edit] Dates of first radio stations

This is a listing of radio stations in broadcast networks. The earliest radio stations were simply radio telegraph systems which did not carry audio are not listed. The included first radio station encompass AM and FM stations; these include both commercial, public and nonprofit varieties found throughout the world.

Note
The first claimed audio transmission that could be termed to be from a broadcast station occurred on Christmas Eve in 1906, and was made by Reginald Fessenden.
Charles Herrold started broadcasting from a station in California in 1909 and was carrying audio by 1910.
Note
Some of the dates listed here may not be accurate. Feel free to make corrections to either of the lists.

[edit] USA and Canadian territory

This list includes the United States of America, the republic composed of 50 states, one federal district, and several insular territories, and the Canadian provinces, which consists of ten provinces with three territories.

State Date
Alabama 1922
Territory of Alaska 1924
Alberta 1922
Arizona 1922
Arkansas 1920
British Columbia 1922
California 1921
Colorado 1921
Connecticut 1922
Delaware 1922
Florida 1921
Georgia 1922
Guam 1954
Territory of Hawaii 1922
Idaho 1922
Illinois 1921
Indiana 1921
Iowa 1922
Kansas 1922
Kentucky 1921
Louisiana 1922
Maine 1922
Manitoba 1922
Maryland 1922
Massachusetts 1920
Michigan 1920
Minnesota 1922
Mississippi 1925 3
Missouri 1921
Montana 1922
Nebraska 1921
Nevada 1922
New Brunswick 1923
New Hampshire 1922
New Jersey 1921
New Mexico 1922
New York 1922
Newfoundland 1924
North Carolina 1922
North Dakota 1922
Northwest Territories 1958
Nova Scotia 1920
Ohio 1922
Oklahoma 1921
Ontario 1922
Oregon 1922
Panama Canal Zone 1923
Pennsylvania 1920
Philippines 1922
Prince Edward Island 1924
Puerto Rico 1922
Quebec 1920
Rhode Island 1922
Saskatchewan 1922
South Carolina 1930 4
South Dakota 1922
Tennessee 1922
Texas 1920
Utah 1922
Vermont 1920
Virginia 1923
Washington 1920
Washington, D.C. 1923
West Virginia 1923
Wisconsin 1922
Wyoming 1930 5
Yukon Territory 1923

[edit] Other countries

This list includes countries outside of the United States of America and the Canadian provinces.

Country Date
The Netherlands 1919
Argentina 1920
Malaya 1921
Mexico 1921
New Zealand 1921
Russia 1921
Uruguay 1921
Ceylon 1922
France 1922
Switzerland 1922
Great Britain 1922
Chile 1922
Cuba 1922
Panama 1922
Venezuela 1922
Germany 1923
Czechoslovakia 1923
China 1923
Australia 1923
Brazil 1923
Belgium 1923
Denmark 1923
Finland 1923
Italy 1923
Netherlands East Indies 1923 5
South Africa 1923
Spain 1923
Sweden 1923
Austria 1923
Colombia 1924
Costa Rica 1924
Estonia 1924
Lithuania 1924
Luxembourg 1924
Serbia 1924
Poland 1924
Norway 1924*
Afghanistan 1925*
Egypt 1925
Japan 1925
Fiji 1925*
Latvia 1925
Peru 1925
Portugal 1925
Romania 1925
Hungary 1925
Ireland 1925
Netherlands Antilles 1925
British Guiana 1926
Free City of Danzig 1926
Dominican Republic 1926
El Salvador 1926
Greece 1926
Guatemala 1926
Lithuania 1926
Algeria 1927*
Basutoland 1927
Belgian Congo 1927
Bolivia 1927
Dutch New Guinea 1927*
Greenland 1927
Haiti 1927
India 1927
Kenya 1927
Liberia 1927
Mauritius 1927
St. Helena 1927*
Siam 1927
Singapore 1927
Suriname 1927*
Turkey 1927
French Indochina 1927
Honduras 1928
Hong Kong 1928
Morocco 1928*
Western Samoa 1928*
Bulgaria 1929
Falkland Islands 1929 6
Mozambique 1929
North Yemen 1929*
British Honduras 1930s *?*
Bermuda 1930
Iceland 1930*
Israel 1930
Tunisia 1930*
Vatican City 1931 7
Ethiopia 1931
Madagascar 1931*
Nicaragua 1931*
Nigeria 1931
Ecuador 1931
British Leeward Islands 1932*
French West Africa 1932*
Macau 1932
Saudi Arabia 1932
Southern Rhodesia 1932
British Windward Islands 1934*
Mongolia 1934
Papua New Guinea 1934
Sierra Leone 1934
Andorra 1935*
Gold Coast 1935
Malta 1935 7
Paraguay 1936
Bahamas 1936 8*
Iraq 1936*
Gilbert and Ellice Islands 1937
Lebanon 1937
Albania 1938 9*
Cyprus 1938
Jamaica 1938
Pitcairn Islands 1938
Trinidad and Tobago 1938
French Equatorial Africa 1939
Libya 1939
Aden 1940 10
Bechuanaland 1940
British Somaliland 1940
Iran 1940*
Anglo-Egyptian Sudan 1940*
Bahrain 1941
Northern Rhodesia 1941
Seychelles 1945
Syria 1945
Brunei 1947*
Spanish Guinea 1947
Transjordan 1948
Nepal 1950
Sao Tome and Principe 1950
Cape Verde Islands 1951
Kuwait 1951
Tanganyika 1951
Portuguese Timor 1960
Maldives 1962
Nauru 1968 12
Qatar 1968 13
South West Africa 1969 14
Oman 1970
Bhutan 1973
  • * Date unconfirmed

[edit] FM and television start

In 1933, FM radio was patented by inventor Edwin H. Armstrong. FM uses frequency modulation of the radio wave to minimize static and interference from electrical equipment and the atmosphere, in the audio program. In 1937, W1XOJ, the first experimental FM radio station, was granted a construction permit by the FCC. In the 1930s, standard analog television transmissions started in Europe, and then in the 1940s in North America.

[edit] Marconi/Tesla priority dispute

Main article: Invention of radio
Timeline of Marconi/Tesla dispute
Timeline of Marconi/Tesla dispute

In 1943, Tesla's patent (number 645576) was reinstated as holding priority in the "invention" of modern radio by the U.S. Supreme Court shortly after Tesla's death. The validity of the patent was never in question in the case. This decision was based on the fact that prior art existed before the establishment of Marconi's patent. Ignoring Tesla's prior art, the decision may have enabled the U.S. government to avoid having to pay damages that were being claimed by the Marconi Company for use of its patents during World War I (as, it is speculated, the government's initial reversal to grant Marconi the patent right in order to nullify any claims Tesla had for compensation).

[edit] FM in Europe

After World War II, the FM radio broadcast was introduced in Germany. In 1948, a new wavelength plan was set up for Europe at a meeting in Copenhagen. 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 medium-wave frequencies, which are not very good for broadcasting. For this reason Germany began broadcasting on UKW ("Ultrakurzwelle", i.e. ultra short wave, nowadays called 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.

[edit] Later 20th century developments

In 1954 Regency introduced a pocket transistor radio, the TR-1, powered by a "standard 22.5V Battery". In the early 1960s, VOR systems finally became widespread for aircraft navigation; before that, aircraft used commercial AM radio stations for navigation. (AM stations are still marked on U.S. aviation charts). In 1960 Sony introduced their first transistorized radio, small enough to fit in a vest pocket, and able to be powered by a small battery. It was durable, because there were no tubes to burn out. Over the next twenty years, transistors displaced tubes almost completely except for very high power, or very high frequency, uses.

[edit] Color television and digital

  • 1963: Color television was commercially transmitted, and the first (radio) communication satellite, Telstar, was launched.
  • Late 1960s: The USA long-distance telephone network began to convert to a digital network, employing digital radios for many of its links.
  • 1970s: LORAN became the premier radio navigation system. Soon, the U.S. Navy experimented with satellite navigation.
  • 1987: The GPS constellation of satellites was launched.
  • Early 1990s: amateur radio experimenters began to use personal computers with audio cards to process radio signals.
  • 1994: The U.S. Army and DARPA launched an aggressive successful project to construct a software radio that could become a different radio on the fly by changing software.
  • Late 1990s: Digital transmissions began to be applied to broadcasting.

[edit] Telex on radio

Telegraphy did not go away on radio. Instead, the degree of automation increased. On land-lines in the 1930s, Teletypewriters automated encoding, and were adapted to pulse-code dialing to automate routing, a service called telex. For thirty years, telex was the absolute 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. 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.

[edit] 21st century development

[edit] Internet radio

Internet radio consists of sending radio-style audio programming over streaming Internet connections: no radio transmitters need be involved at any point in the process.

  • Early technology wars: Push or pull, streaming media or multicast

[edit] Digital audio broadcasting

Digital audio broadcasting (DAB): appears to be set to grow in importance relative to FM radio for airborne broadcasts in several countries.

[edit] Related articles

[edit] Legal issues with radio

When radio was first introduced in the 1930’s many predicted the end of records. 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, other feared it would cut into profits from record sales and live performances. Many companies had their major stars sign agreements that they would not appear on radio. [25][26]

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 2 out of 5 homes in 1931 to 4 out of 5 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). Although it should be noted that the economics of the situation were also affected by the fact this took place during the Great Depression.[27]

The copyright owners of these songs were concerned that they would see no gain from the popularity of radio and the ‘free’ music it provided. Luckily, everything 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 was against Bamberger Department Store in Newark, New Jersey in 1922. The store was broadcasting music throughout its store on the radio station WOR. No advertisements were heard, except for 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 $230 for all music protected under ASCAP, but for larger stations the price soon ballooned up to $5,000. Edward Samuel’s 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 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.[28]

[edit] Exotic technologies

[edit] See also

Wikimedia Commons has media related to:

[edit] Notes and Citations

  1. Broadcasts had also been available from Louisiana and Alabama since 1922.
  2. Broadcasts were also available from North Carolina and Georgia.
  3. Broadcasts were also available from Colorado since 1921.
  4. Radio broadcasting in Java briefly ceased after a station was destroyed by lightning.
  5. Broadcasts from Argentina had also been available as is the case today.
  6. Radio broadcasting had also been received from Italy, since Vatican City lies within the vicinity of Rome as is the case today.
  7. Radio broadcasts did exist in the Bahamas prior to 1936. Before then, they were received from the United States.
  8. Also received radio broadcasts from nearby Yugoslavia.
  9. Broadcasting in Aden ceased in 1946-1947 and again from 1948-1955.
  10. Andorra also received radio broadcasts from Spain.
  11. Radio broadcasts from the Trust Territory of the Pacific Islands had also been available.
  12. Broadcasts had also been received from Saudi Arabia and Bahrain.
  13. Broadcasts had previously been received from South Africa
  14. Malta had also received radio broadcasts from Italy. The British adopted a radio service on the island to counter Fascist propaganda.

[edit] Footnotes

  1. ^ "Wireless telegraphy". Scientific American, June 19, 1897, page 386. Uses the term to connote "aether's conduction".
  2. ^ "The Slaby system of wireless duplex telegraphy". Scientific American, March 9, 1901, pages 146-147. Uses the term to connote "aether's conduction".
  3. ^ "The True Wireless" by Nikola Tesla
  4. ^ "Nikola Tesla". ieee-virtual-museum.org
  5. ^ "On Light and Other High Frequency Phenomena". Philadelphia/St. Louis; Franklin Institute in 1893.
  6. ^ Corum, K. L., and J. F. Corum, "Tesla's Colorado Springs Receivers (A Short Introduction)".
  7. ^ Sir Oliver Lodge Invented Radio - Not Marconi".
  8. ^ Peter Rowlands (ed.) and J. Patrick Wilson (ed.) "Oliver Lodge and the Invention of Radio" ISBN 1-873694-02-4
  9. ^ "Jagadish Chandra Bose". ieee-virtual-museum.org.
  10. ^ "The Work of Jagdish Chandra Bose: 100 years of mm-wave research". tuc.nrao.edu.
  11. ^ "Jagadish Chandra Bose", ieee-virtual-museum.org.
  12. ^ Early Radio Transmission Recognized as Milestone. IEEE. Retrieved on July 16, 2006.
  13. ^ "Popov's Contribution to the Development of Wireless Communication, 1895". IEEE History Center, IEEE Milestone.
  14. ^ "Russia's Popov: Did he "invent" radio?". The First Electronic Church of America.
  15. ^ Л.Н.Никольский. Кто "изобрел" радио?
  16. ^ "The Guglielmo Marconi Case Who is the True Inventor of Radio".
  17. ^ "The Electronic Era; When? Where? Who? How? Why?". First Electronic Church Of America.
  18. ^ "Nikola Tesla On His Work with Alternating Currents and Their Application to wireless Telegraphy, Telephony, and Transmission of Power", Leland I. Anderson, Twenty First Century Books, 2002, pp. 25-29.
  19. ^ Noticias, Últimas noticias, El español Julio Cervera Baviera, y no Marconi, fue quien inventó la radio, según el profesor Ángel Faus . Universidad de Navarra
  20. ^ Un estudio asegura que fue el español Cervera Baviera y no Marconi el inventor de la radio - comunicación - elmundo.es
  21. ^ News, Latest news, The Spaniard Julio Cervera Baviera, and not Marconi, was the inventor of the radio, according to professor Ángel Faus . University of Navarra
  22. ^ Domenico Mazzotto, Wireless Telegraphy and Telephony. Translated by Selimo Romeo Bottone (Whittaker & Co., 1906), 217.
  23. ^ http://www.coit.es/foro/pub/ficheros/librosapendice_1_981ff066.pdf?PHPSESSID=c3606fd8d59137417f50e69e7d8f8566
  24. ^ "North Hall." Concise Encyclopedia of Tufts History. Ed. Anne Sauer [1]
  25. ^ liebowitz.dvi
  26. ^ frontline: the way the music died: inside the music industry: chronology - technology and the music industry | PBS
  27. ^ Creativity Wants to be Paid
  28. ^ Chapter Two

[edit] References

[edit] Primary sources

  • 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, MA. 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).

[edit] Secondary sources

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  • Anderson, Leland I. Priority in the Invention of Radio — 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).
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  • Briggs, Asa. The History of Broadcasting in the United Kingdom (Oxford University Press, 1961).
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  • Coe, Douglas and Kreigh Collins (ills), "Marconi, pioneer of radio". New York, J. Messner, Inc., 1943. LCCN 43010048
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  • Geddes, Keith, "Guglielmo Marconi, 1874-1937". London : H.M.S.O., A Science Museum booklet, 1974. ISBN 0-11-290198-0 LCCN 75329825 (ed. Obtainable in the U.S.A. from Pendragon House Inc., Palo Alto, California.)
  • Gibson, George H. Public Broadcasting; The Role of the Federal Government, 1919-1976 (Praeger Publishers, 1977).
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  • Jackaway, Gwenyth L. Media at War: Radio's Challenge to the Newspapers, 1924-1939 Praeger Publishers, 1995
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  • Katz, Randy H., "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).
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  • Marincic, Aleksandar and Djuradj Budimir, "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)
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  • The Prestige, 2006, Touchstone Pictures.
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  • Ray, William B. FCC: The Ups and Downs of Radio-TV Regulation (Iowa State University Press, 1990).
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  • 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).
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  • 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).
  • Stone, John Stone. "John Stone Stone on Nikola Tesla's Priority in Radio and Continuous-Wave Radiofrequency Apparatus". Twenty First Century Books, 2005.
  • Sungook Hong, "Wireless: from Marconi's Black-box to the Audion", Cambridge, MA: MIT Press, 2001, ISBN 0-262-08298-5
  • Waldron, Richard Arthur, "Theory of guided electromagnetic waves". London, New York, Van Nostrand Reinhold, 1970. ISBN 0-442-09167-2 LCCN 69019848 //r86
  • 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, MA : Da Capo Press, 2003.
  • White, Llewellyn. The American Radio (University of Chicago Press, 1947).
  • White, Thomas H. "Pioneering U.S. Radio Activities (1897-1917)", United States Early Radio History.
  • Wunsch, A. David "Misreading the Supreme Court: A Puzzling Chapter in the History of Radio". Mercurians.org.

[edit] External links


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