AM broadcasting is radio broadcasting using amplitude modulation (AM) transmissions. It was the first method developed for making audio radio transmissions, and is still used worldwide, primarily for medium wave (also known as "AM band") transmissions, but also on the longwave and shortwave radio bands.
139-660: KSWA 1330 AM was a radio station licensed to serve Graham, Texas . The station aired a News Talk format in a simulcast with KROO Breckenridge, Texas. Both stations were owned by Terry and Kay Slavens, through licensee For the Love of the Game Broadcasting, LLC. On August 29, 2023, both KSWA's and KROO's licenses were surrendered to the Federal Communications Commission ; the FCC cancelled
278-477: A world's fair to celebrate the centennial of the French Revolution . In May 1884, working at home, Koechlin made a sketch of their idea, described by him as "a great pylon, consisting of four lattice girders standing apart at the base and coming together at the top, joined together by metal trusses at regular intervals". Eiffel initially showed little enthusiasm, but he did approve further study, and
417-472: A "chain". The Radio Corporation of America (RCA), General Electric , and Westinghouse organized a competing network around its own flagship station, RCA's WJZ (now WABC) in New York City, but were hampered by AT&T's refusal to lease connecting lines or allow them to sell airtime. In 1926 AT&T sold its radio operations to RCA, which used them to form the nucleus of the new NBC network. By
556-846: A 10 shilling receiver license fee. Both highbrow and mass-appeal programmes were carried by the National and Regional networks. The period from the early 1920s through the 1940s is often called the "Golden Age of Radio". During this period AM radio was the main source of home entertainment, until it was replaced by television. For the first time entertainment was provided from outside the home, replacing traditional forms of entertainment such as oral storytelling and music from family members. New forms were created, including radio plays , mystery serials, soap operas , quiz shows , variety hours , situation comedies and children's shows . Radio news, including remote reporting, allowed listeners to be vicariously present at notable events. Radio greatly eased
695-570: A central station to all parts of the United States", he was unable to overcome the inherent distance limitations of this technology. The earliest public radiotelegraph broadcasts were provided as government services, beginning with daily time signals inaugurated on January 1, 1905, by a number of U.S. Navy stations. In Europe, signals transmitted from a station located on the Eiffel Tower were received throughout much of Europe. In both
834-436: A commission was set up to examine Eiffel's scheme and its rivals, which, a month later, decided that all the proposals except Eiffel's were either impractical or lacking in details. After some debate about the exact location of the tower, a contract was signed on 8 January 1887. Eiffel signed it acting in his own capacity rather than as the representative of his company, the contract granting him 1.5 million francs toward
973-610: A concerted attempt to specify performance of AM receivers through the 1993 AMAX standard, a joint effort of the EIA and the NAB, with FCC backing... The FCC rapidly followed up on this with codification of the CQUAM AM stereo standard, also in 1993. At this point, the stage appeared to be set for rejuvenation of the AM band. Nevertheless, with the legacy of confusion and disappointment in the rollout of
1112-635: A consortium, the British Broadcasting Company (BBC), established on 18 October 1922, which was given a monopoly on broadcasting. This enterprise was supported by a tax on radio sets sales, plus an annual license fee on receivers, collected by the Post Office. Initially the eight stations were allowed regional autonomy. In 1927, the original broadcasting organization was replaced by a government chartered British Broadcasting Corporation . an independent nonprofit supported solely by
1251-564: A continuous-wave (CW) transmitter. Fessenden began his research on audio transmissions while doing developmental work for the United States Weather Service on Cobb Island, Maryland. Because he did not yet have a continuous-wave transmitter, initially he worked with an experimental "high-frequency spark" transmitter, taking advantage of the fact that the higher the spark rate, the closer a spark-gap transmission comes to producing continuous waves. He later reported that, in
1390-400: A depth of 22 m (72 ft) to support the concrete slabs, which were 6 m (20 ft) thick. Each of these slabs supported a block of limestone with an inclined top to bear a supporting shoe for the ironwork. Each shoe was anchored to the stonework by a pair of bolts 10 cm (4 in) in diameter and 7.5 m (25 ft) long. The foundations were completed on 30 June, and
1529-580: A few " telephone newspaper " systems, most of which were established in Europe, beginning with the Paris Théâtrophone . With this in mind, most early radiotelephone development envisioned that the device would be more profitably developed as a "wireless telephone" for personal communication, or for providing links where regular telephone lines could not be run, rather than for the uncertain finances of broadcasting. The person generally credited as
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#17328023352571668-463: A few hundred ( Hz ), to increase its rotational speed and so generate currents of tens-of-thousands Hz, thus producing a steady continuous-wave transmission when connected to an aerial. The next step, adopted from standard wire-telephone practice, was to insert a simple carbon microphone into the transmission line, to modulate the carrier wave signal to produce AM audio transmissions. However, it would take many years of expensive development before even
1807-534: A few, including the structural engineer, Émile Nouguier, the head of construction, Jean Compagnon, the President of the City Council, and reporters from Le Figaro and Le Monde Illustré , completed the ascent. At 2:35 pm, Eiffel hoisted a large Tricolour to the accompaniment of a 25-gun salute fired at the first level. There was still work to be done, particularly on the lifts and facilities, and
1946-516: A home audio device prior to the introduction of the high-fidelity , long-playing record in the late 1940s. Listening habits changed in the 1960s due to the introduction of the revolutionary transistor radio (Regency TR-1, the first transistor radio released December 1954), which was made possible by the invention of the transistor in 1948. (The transistor was invented at Bell labs and released in June 1948.) Their compact size — small enough to fit in
2085-485: A journalist that it was premature to judge the effect of the tower solely on the basis of the drawings, that the Champ de Mars was distant enough from the monuments mentioned in the protest for there to be little risk of the tower overwhelming them, and putting the aesthetic argument for the tower: "Do not the laws of natural forces always conform to the secret laws of harmony?" Some of the protesters changed their minds when
2224-474: A listening site at Plymouth, Massachusetts. An American Telephone Journal account of the December 21 alternator-transmitter demonstration included the statement that "It is admirably adapted to the transmission of news, music, etc. as, owing to the fact that no wires are needed, simultaneous transmission to many subscribers can be effected as easily as to a few", echoing the words of a handout distributed to
2363-537: A long-standing debate in France about the relationship between architecture and engineering. It came to a head as work began at the Champ de Mars: a "Committee of Three Hundred" (one member for each metre of the tower's height) was formed, led by the prominent architect Charles Garnier and including some of the most important figures of the arts, such as William-Adolphe Bouguereau , Guy de Maupassant , Charles Gounod and Jules Massenet . A petition called "Artists against
2502-487: A majority of early broadcasting stations operated on mediumwave frequencies, whose limited range generally restricted them to local audiences. One method for overcoming this limitation, as well as a method for sharing program costs, was to create radio networks , linking stations together with telephone lines to provide a nationwide audience. In the U.S., the American Telephone and Telegraph Company (AT&T)
2641-719: A moment a giddy, ridiculous tower dominating Paris like a gigantic black smokestack, crushing under its barbaric bulk Notre Dame, the Tour Saint-Jacques, the Louvre, the Dome of les Invalides, the Arc de Triomphe, all of our humiliated monuments will disappear in this ghastly dream. And for twenty years ... we shall see stretching like a blot of ink the hateful shadow of the hateful column of bolted sheet metal. Gustave Eiffel responded to these criticisms by comparing his tower to
2780-457: A national scale. The introduction of nationwide talk shows, most prominently Rush Limbaugh 's beginning in 1988, was sometimes credited with "saving" AM radio. However, these stations tended to attract older listeners who were of lesser interest to advertisers, and AM radio's audience share continued to erode. In 1961, the FCC adopted a single standard for FM stereo transmissions, which was widely credited with enhancing FM's popularity. Developing
2919-399: A policy allowing AM stations to simulcast over FM translator stations. Translators had previously been available only to FM broadcasters, in order to increase coverage in fringe areas. Their assignment for use by AM stations was intended to approximate the station's daytime coverage, which in cases where the stations reduced power at night, often resulted in expanded nighttime coverage. Although
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#17328023352573058-486: A prototype alternator-transmitter would be ready, and a few years beyond that for high-power versions to become available. Fessenden worked with General Electric 's (GE) Ernst F. W. Alexanderson , who in August 1906 delivered an improved model which operated at a transmitting frequency of approximately 50 kHz, although at low power. The alternator-transmitter achieved the goal of transmitting quality audio signals, but
3197-423: A result, AM radio tends to do best in areas where FM frequencies are in short supply, or in thinly populated or mountainous areas where FM coverage is poor. Great care must be taken to avoid mutual interference between stations operating on the same frequency. In general, an AM transmission needs to be about 20 times stronger than an interfering signal to avoid a reduction in quality, in contrast to FM signals, where
3336-452: A shirt pocket — and lower power requirements, compared to vacuum tubes, meant that for the first time radio receivers were readily portable. The transistor radio became the most widely used communication device in history, with billions manufactured by the 1970s. Radio became a ubiquitous "companion medium" which people could take with them anywhere they went. The demarcation between what is considered "experimental" and "organized" broadcasting
3475-427: A short-range "wireless telephone" demonstration, that included simultaneously broadcasting speech and music to seven locations throughout Murray, Kentucky. However, this was transmitted using induction rather than radio signals, and although Stubblefield predicted that his system would be perfected so that "it will be possible to communicate with hundreds of homes at the same time", and "a single message can be sent from
3614-461: A widespread audience — dates back to the founding period of radio development, even though the earliest radio transmissions, originally known as "Hertzian radiation" and "wireless telegraphy", used spark-gap transmitters that could only transmit the dots-and-dashes of Morse code . In October 1898 a London publication, The Electrician , noted that "there are rare cases where, as Dr. [Oliver] Lodge once expressed it, it might be advantageous to 'shout'
3753-521: A year, and in 1957, the present radio aerial was added to the top. In 1964, the Eiffel Tower was officially declared to be a historical monument by the Minister of Cultural Affairs, André Malraux . A year later, an additional lift system was installed in the north pillar. According to interviews, in 1967, Montreal Mayor Jean Drapeau negotiated a secret agreement with Charles de Gaulle for
3892-491: Is a private apartment built for Gustave Eiffel's personal use. He decorated it with furniture by Jean Lachaise and invited friends such as Thomas Edison . The design of the Eiffel Tower is attributed to Maurice Koechlin and Émile Nouguier , two senior engineers working for the Compagnie des Établissements Eiffel . It was envisioned after discussion about a suitable centerpiece for the proposed 1889 Exposition Universelle ,
4031-406: Is comparable to or better in audio quality than a standard analog broadcast". Despite the various actions, AM band audiences continued to contract, and the number of stations began to slowly decline. A 2009 FCC review reported that "The story of AM radio over the last 50 years has been a transition from being the dominant form of audio entertainment for all age groups to being almost non-existent to
4170-502: Is largely arbitrary. Listed below are some of the early AM radio broadcasts, which, due to their irregular schedules and limited purposes, can be classified as "experimental": People who weren't around in the Twenties when radio exploded can't know what it meant, this milestone for mankind. Suddenly, with radio, there was instant human communication. No longer were our homes isolated and lonely and silent. The world came into our homes for
4309-645: Is simpler than later transmission systems. An AM receiver detects amplitude variations in the radio waves at a particular frequency, then amplifies changes in the signal voltage to operate a loudspeaker or earphone . However, the simplicity of AM transmission also makes it vulnerable to "static" ( radio noise , radio frequency interference ) created by both natural atmospheric electrical activity such as lightning, and electrical and electronic equipment, including fluorescent lights, motors and vehicle ignition systems. In large urban centers, AM radio signals can be severely disrupted by metal structures and tall buildings. As
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4448-538: Is square, measuring 125 metres (410 ft) on each side. During its construction, the Eiffel Tower surpassed the Washington Monument to become the tallest human-made structure in the world, a title it held for 41 years until the Chrysler Building in New York City was finished in 1930. It was the first structure in the world to surpass both the 200-metre and 300-metre mark in height. Due to
4587-509: Is the most visited monument with an entrance fee in the world: 6.91 million people ascended it in 2015. It was designated a monument historique in 1964, and was named part of a UNESCO World Heritage Site ("Paris, Banks of the Seine") in 1991. The tower is 330 metres (1,083 ft) tall, about the same height as an 81-storey building, and the tallest structure in Paris . Its base
4726-577: Is widely considered to be a remarkable piece of structural art , and is often featured in films and literature. Work on the foundations started on 28 January 1887. Those for the east and south legs were straightforward, with each leg resting on four 2 m (6.6 ft) concrete slabs, one for each of the principal girders of each leg. The west and north legs, being closer to the river Seine , were more complicated: each slab needed two piles installed by using compressed-air caissons 15 m (49 ft) long and 6 m (20 ft) in diameter driven to
4865-514: The Egyptian pyramids : "My tower will be the tallest edifice ever erected by man. Will it not also be grandiose in its way? And why would something admirable in Egypt become hideous and ridiculous in Paris?" These criticisms were also dealt with by Édouard Lockroy in a letter of support written to Alphand, sardonically saying, "Judging by the stately swell of the rhythms, the beauty of the metaphors,
5004-578: The Electronic Industries Association (EIA) and the National Association of Broadcasters (NAB) with the intention of helping AM stations, especially ones with musical formats, become more competitive with FM broadcasters by promoting better quality receivers. However, the stereo AM and AMAX initiatives had little impact, and a 2015 review of these events concluded that Initially the consumer manufacturers made
5143-625: The Emergency Alert System (EAS). Some automakers have been eliminating AM radio from their electric vehicles (EVs) due to interference from the electric motors , but the lawmakers argue that this is a safety risk and that car owners should have access to AM radio regardless of the type of vehicle they drive. The proposed legislation would require all new vehicles to include AM radio at no additional charge, and it would also require automakers that have already eliminated AM radio to inform customers of alternatives. AM radio technology
5282-493: The Federal Emergency Management Agency (FEMA) expressed concerns that this would reduce the effectiveness of emergency communications. In May 2023, a bipartisan group of lawmakers in the United States introduced legislation making it illegal for automakers to eliminate AM radio from their cars. The lawmakers argue that AM radio is an important tool for public safety due to being a component of
5421-481: The ambient temperature , the top of the tower may shift away from the sun by up to 18 cm (7 in) due to thermal expansion of the metal on the side facing the sun. When it was built, Eiffel was accused of trying to create something artistic with no regard to the principles of engineering. However, Eiffel and his team were experienced bridge builders. In an interview with the newspaper Le Temps published on 14 February 1887, Eiffel said: Is it not true that
5560-431: The electrolytic detector and thermionic diode ( Fleming valve ) were invented by Reginald Fessenden and John Ambrose Fleming , respectively. Most important, in 1904–1906 the crystal detector , the simplest and cheapest AM detector, was developed by G. W. Pickard . Homemade crystal radios spread rapidly during the next 15 years, providing ready audiences for the first radio broadcasts. One limitation of crystals sets
5699-430: The " capture effect " means that the dominant signal needs to only be about twice as strong as the interfering one. To allow room for more stations on the mediumwave broadcast band in the United States, in June 1989 the FCC adopted a National Radio Systems Committee (NRSC) standard that limited maximum transmitted audio bandwidth to 10.2 kHz, limiting occupied bandwidth to 20.4 kHz. The former audio limitation
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5838-603: The 1930s, most of the major radio stations in the country were affiliated with networks owned by two companies, NBC and CBS . In 1934, a third national network, the Mutual Radio Network , was formed as a cooperative owned by its stations. A second country which quickly adopted network programming was the United Kingdom, and its national network quickly became a prototype for a state-managed monopoly of broadcasting. A rising interest in radio broadcasting by
5977-660: The 1940s two new broadcast media, FM radio and television , began to provide extensive competition with the established broadcasting services. The AM radio industry suffered a serious loss of audience and advertising revenue, and coped by developing new strategies. Network broadcasting gave way to format broadcasting: instead of broadcasting the same programs all over the country, stations individually adopted specialized formats which appealed to different audiences, such as regional and local news, sports, "talk" programs, and programs targeted at minorities. Instead of live music, most stations began playing less expensive recorded music. In
6116-532: The AM radio industry in the United States developed technology for broadcasting in stereo . Other nations adopted AM stereo, most commonly choosing Motorola's C-QUAM, and in 1993 the United States also made the C-QUAM system its standard, after a period allowing four different standards to compete. The selection of a single standard improved acceptance of AM stereo , however overall there was limited adoption of AM stereo worldwide, and interest declined after 1990. With
6255-768: The Allied victory at the First Battle of the Marne . During World War I , the Eiffel Tower's wireless station played a crucial role in intercepting enemy communications from Berlin. In 1914, French forces successfully launched a counter-attack during the Battle of the Marne after gaining critical intelligence on the German Army's movements. In 1917, the station intercepted a coded message between Germany and Spain that referenced 'Operative H-21.' This information contributed to
6394-531: The British public pressured the government to reintroduce the service, following its suspension in 1920. However, the government also wanted to avoid what it termed the "chaotic" U.S. experience of allowing large numbers of stations to operate with few restrictions. There were also concerns about broadcasting becoming dominated by the Marconi company. Arrangements were made for six large radio manufacturers to form
6533-506: The CIC and its partner nearly half of all taxes collected on exports, "effectively choking off the nation's primary source of income". According to The New York Times , "[at] a time when the [CIC] was helping finance one of the world's best-known landmarks, the Eiffel Tower, as a monument to French liberty, it was choking Haiti's economy, taking much of the young nation's income back to Paris and impairing its ability to start schools, hospitals and
6672-427: The Eiffel Tower began hosting a seasonal ice rink on the first level. A glass floor was installed on the first level during the 2014 refurbishment. The puddle iron (wrought iron) of the Eiffel Tower weighs 7,300 tonnes , and the addition of lifts, shops and antennae have brought the total weight to approximately 10,100 tonnes. As a demonstration of the economy of design, if the 7,300 tonnes of metal in
6811-559: The Eiffel Tower" was sent to the Minister of Works and Commissioner for the Exposition, Adolphe Alphand , and it was published by Le Temps on 14 February 1887: We, writers, painters, sculptors, architects and passionate devotees of the hitherto untouched beauty of Paris, protest with all our strength, with all our indignation in the name of slighted French taste, against the erection ... of this useless and monstrous Eiffel Tower ... To bring our arguments home, imagine for
6950-559: The Eiffel Tower. During the period of the tower's construction, the CIC was acquiring funds from predatory loans to the National Bank of Haiti , some of which went towards the financing of the tower. These loans were connected to an indemnity controversy that saw France force Haiti's government to financially compensate French slaveowners for lost income as a result of the Haitian Revolution , and required Haiti to pay
7089-473: The French newspaper Le Figaro had an office and a printing press, where a special souvenir edition, Le Figaro de la Tour , was made. At the top, there was a post office where visitors could send letters and postcards as a memento of their visit. Graffitists were also catered for: sheets of paper were mounted on the walls each day for visitors to record their impressions of the tower. Gustave Eiffel described
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#17328023352577228-411: The Twenties when radio exploded can't know what it meant, this milestone for mankind. Suddenly, with radio, there was instant human communication. No longer were our homes isolated and lonely and silent. The world came into our homes for the first time. Music came pouring in. Laughter came in. News came in. The world shrank, with radio. The idea of broadcasting — the unrestricted transmission of signals to
7367-581: The U.S., for example) subject to international agreements. Eiffel Tower The Eiffel Tower ( / ˈ aɪ f əl / EYE -fəl ; French : Tour Eiffel [tuʁ ɛfɛl] ) is a wrought-iron lattice tower on the Champ de Mars in Paris , France. It is named after the engineer Gustave Eiffel , whose company designed and built the tower from 1887 to 1889. Locally nicknamed " La dame de fer " (French for "Iron Lady"), it
7506-641: The United States and France this led to a small market of receiver lines geared for jewelers who needed accurate time to set their clocks, including the Ondophone in France, and the De Forest RS-100 Jewelers Time Receiver in the United States The ability to pick up time signal broadcasts, in addition to Morse code weather reports and news summaries, also attracted the interest of amateur radio enthusiasts. It
7645-559: The addition of a broadcasting aerial at the top of the tower in 1957, it is now taller than the Chrysler Building by 5.2 metres (17 ft). Excluding transmitters, the Eiffel Tower is the second tallest free-standing structure in France after the Millau Viaduct . The tower has three levels for visitors, with restaurants on the first and second levels. The top level's upper platform is 276 m (906 ft) above
7784-523: The antenna wire. This meant that the full transmitter power flowed through the microphone, and even using water cooling, the power handling ability of the microphones severely limited the power of the transmissions. Ultimately only a small number of large and powerful Alexanderson alternators would be developed. However, they would be almost exclusively used for long-range radiotelegraph communication, and occasionally for radiotelephone experimentation, but were never used for general broadcasting. Almost all of
7923-454: The arrest, conviction, and execution of Mata Hari , the famous spy accused of working for Germany. From 1925 to 1934, illuminated signs for Citroën adorned three of the tower's sides, making it the tallest advertising space in the world at the time. In April 1935, the tower was used to make experimental low-resolution television transmissions, using a shortwave transmitter of 200 watts power. On 17 November, an improved 180-line transmitter
8062-482: The audience has continued to decline. In 1987, the elimination of the Fairness Doctrine requirement meant that talk shows, which were commonly carried by AM stations, could adopt a more focused presentation on controversial topics, without the distraction of having to provide airtime for any contrasting opinions. In addition, satellite distribution made it possible for programs to be economically carried on
8201-488: The century of Industry and Science in which we are living, and for which the way was prepared by the great scientific movement of the eighteenth century and by the Revolution of 1789, to which this monument will be built as an expression of France's gratitude. Little progress was made until 1886, when Jules Grévy was re-elected as president of France and Édouard Lockroy was appointed as minister for trade. A budget for
8340-404: The characteristics of arc-transmitters . Fessenden attempted to sell this form of radiotelephone for point-to-point communication, but was unsuccessful. Fessenden's work with high-frequency spark transmissions was only a temporary measure. His ultimate plan for creating an audio-capable transmitter was to redesign an electrical alternator , which normally produced alternating current of at most
8479-464: The collection of responses as "truly curious". Famous visitors to the tower included the Prince of Wales , Sarah Bernhardt , "Buffalo Bill" Cody (his Wild West show was an attraction at the exposition) and Thomas Edison . Eiffel invited Edison to his private apartment at the top of the tower, where Edison presented him with one of his phonographs , a new invention and one of the many highlights of
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#17328023352578618-403: The commission estimated that fewer than 250 AM stations were transmitting hybrid mode signals. On October 27, 2020, the FCC voted to allow AM stations to eliminate their analog transmissions and convert to all-digital operation, with the requirement that stations making the change had to continue to make programming available over "at least one free over-the-air digital programming stream that
8757-482: The construction costs: less than a quarter of the estimated 6.5 million francs. Eiffel was to receive all income from the commercial exploitation of the tower during the exhibition and for the next 20 years. He later established a separate company to manage the tower, putting up half the necessary capital himself. A French bank, the Crédit Industriel et Commercial (CIC), helped finance the construction of
8896-475: The continued migration of AM stations away from music to news, sports, and talk formats, receiver manufacturers saw little reason to adopt the more expensive stereo tuners, and thus radio stations have little incentive to upgrade to stereo transmission. In countries where the use of directional antennas is common, such as the United States, transmitter sites consisting of multiple towers often occupy large tracts of land that have significantly increased in value over
9035-437: The continuous wave AM transmissions made prior to 1915 were made by versions of the arc converter transmitter, which had been initially developed by Valdemar Poulsen in 1903. Arc transmitters worked by producing a pulsating electrical arc in an enclosed hydrogen atmosphere. They were much more compact than alternator transmitters, and could operate on somewhat higher transmitting frequencies. However, they suffered from some of
9174-434: The decades, to the point that the value of land exceeds that of the station itself. This sometimes results in the sale of the transmitter site, with the station relocating to a more distant shared site using significantly less power, or completely shutting down operations. The ongoing development of alternative transmission systems, including Digital Audio Broadcasting (DAB), satellite radio, and HD (digital) radio, continued
9313-567: The decline of the popularity of the traditional broadcast technologies. These new options, including the introduction of Internet streaming, particularly resulted in the reduction of shortwave transmissions, as international broadcasters found ways to reach their audiences more easily. In 2022 it was reported that AM radio was being removed from a number of electric vehicle (EV) models, including from cars manufactured by Tesla, Audi, Porsche, BMW and Volvo, reportedly due to automakers concerns that an EV's higher electromagnetic interference can disrupt
9452-569: The demonstration witnesses, which stated "[Radio] Telephony is admirably adapted for transmitting news, stock quotations, music, race reports, etc. simultaneously over a city, on account of the fact that no wires are needed and a single apparatus can distribute to ten thousand subscribers as easily as to a few. It is proposed to erect stations for this purpose in the large cities here and abroad." However, other than two holiday transmissions reportedly made shortly after these demonstrations, Fessenden does not appear to have conducted any radio broadcasts for
9591-510: The design was put on display at the Exhibition of Decorative Arts in the autumn of 1884 under the company name. On 30 March 1885, Eiffel presented his plans to the Société des Ingénieurs Civils ; after discussing the technical problems and emphasising the practical uses of the tower, he finished his talk by saying the tower would symbolise [n]ot only the art of the modern engineer, but also
9730-487: The early 20th century, particularly radio telegraphy , it was allowed to remain after the expiry of the permit, and from 1910 it also became part of the International Time Service. For the 1900 Exposition Universelle , the lifts in the east and west legs were replaced by lifts running as far as the second level constructed by the French firm Fives-Lille. These had a compensating mechanism to keep
9869-518: The elegance of its delicate and precise style, one can tell this protest is the result of collaboration of the most famous writers and poets of our time", and he explained that the protest was irrelevant since the project had been decided upon months before, and construction on the tower was already under way. Garnier was a member of the Tower Commission that had examined the various proposals, and had raised no objection. Eiffel pointed out to
10008-399: The end of the exhibition there had been 1,896,987 visitors. After dark, the tower was lit by hundreds of gas lamps, and a beacon sent out three beams of red, white and blue light. Two searchlights mounted on a circular rail were used to illuminate various buildings of the exposition. The daily opening and closing of the exposition were announced by a cannon at the top. On the second level,
10147-416: The erection of the ironwork began. The visible work on-site was complemented by the enormous amount of exacting preparatory work that took place behind the scenes: the drawing office produced 1,700 general drawings and 3,629 detailed drawings of the 18,038 different parts needed. The task of drawing the components was complicated by the complex angles involved in the design and the degree of precision required:
10286-648: The expectation is that listeners will primarily be tuning into the FM signal rather than the nominally "primary" AM station. A 2020 review noted that "for many owners, keeping their AM stations on the air now is pretty much just about retaining their FM translator footprint rather than keeping the AM on the air on its own merits". In 2018 the FCC, led by then-Commission Chairman Ajit Pai , proposed greatly reducing signal protection for 50 kW Class A " clear channel " stations. This would allow co-channel secondary stations to operate with higher powers, especially at night. However,
10425-430: The exposition was passed and, on 1 May, Lockroy announced an alteration to the terms of the open competition being held for a centrepiece to the exposition, which effectively made the selection of Eiffel's design a foregone conclusion, as entries had to include a study for a 300 m (980 ft) four-sided metal tower on the Champ de Mars. (A 300-metre tower was then considered a herculean engineering effort.) On 12 May,
10564-593: The exposition. Edison signed the guestbook with this message: To M Eiffel the Engineer the brave builder of so gigantic and original specimen of modern Engineering from one who has the greatest respect and admiration for all Engineers including the Great Engineer the Bon Dieu, Thomas Edison. Eiffel made use of his apartment at the top of the tower to carry out meteorological observations , and also used
10703-399: The eyes of the observer the boldness of the design as a whole. He used graphical methods to determine the strength of the tower and empirical evidence to account for the effects of wind, rather than a mathematical formula. Close examination of the tower reveals a basically exponential shape. All parts of the tower were overdesigned to ensure maximum resistance to wind forces. The top half
10842-445: The fall of 1900, he successfully transmitted speech over a distance of about 1.6 kilometers (one mile), which appears to have been the first successful audio transmission using radio signals. However, at this time the sound was far too distorted to be commercially practical. For a time he continued working with more sophisticated high-frequency spark transmitters, including versions that used compressed air, which began to take on some of
10981-401: The first time. Music came pouring in. Laughter came in. News came in. The world shrank, with radio. Following World War I, the number of stations providing a regular broadcasting service greatly increased, primarily due to advances in vacuum-tube technology. In response to ongoing activities, government regulators eventually codified standards for which stations could make broadcasts intended for
11120-477: The floor level as the angle of ascent changed at the first level, and were driven by a similar hydraulic mechanism as the Otis lifts, although this was situated at the base of the tower. Hydraulic pressure was provided by pressurised accumulators located near this mechanism. At the same time the lift in the north pillar was removed and replaced by a staircase to the first level. The layout of both first and second levels
11259-624: The general public, for example, in the United States formal recognition of a "broadcasting service" came with the establishment of regulations effective December 1, 1921, and Canadian authorities created a separate category of "radio-telephone broadcasting stations" in April 1922. However, there were numerous cases of entertainment broadcasts being presented on a regular schedule before their formal recognition by government regulators. Some early examples include: Because most longwave radio frequencies were used for international radiotelegraph communication,
11398-417: The general public, or to have even given additional thought about the potential of a regular broadcast service, and in a 1908 article providing a comprehensive review of the potential uses for his radiotelephone invention, he made no references to broadcasting. Because there was no way to amplify electrical currents at this time, modulation was usually accomplished by a carbon microphone inserted directly in
11537-514: The ground—the highest observation deck accessible to the public in the European Union . Tickets can be purchased to ascend by stairs or lift to the first and second levels. The climb from ground level to the first level is over 300 steps, as is the climb from the first level to the second, making the entire ascent a 600 step climb. Although there is a staircase to the top level, it is usually accessible only by lift. On this top, third level
11676-485: The hour. The lights sparkled blue for several nights to herald the new millennium on 31 December 2000. The sparkly lighting continued for 18 months until July 2001. The sparkling lights were turned on again on 21 June 2003, and the display was planned to last for 10 years before they needed replacing. The tower received its 200,000,000th guest on 28 November 2002. The tower has operated at its maximum capacity of about 7 million visitors per year since 2003. In 2004,
11815-554: The isolation of rural life. Political officials could now speak directly to millions of citizens. One of the first to take advantage of this was American president Franklin Roosevelt , who became famous for his fireside chats during the Great Depression . However, broadcasting also provided the means to use propaganda as a powerful government tool, and contributed to the rise of fascist and communist ideologies. In
11954-411: The lack of any way to amplify the signals meant they were somewhat weak. On December 21, 1906, Fessenden made an extensive demonstration of the new alternator-transmitter at Brant Rock, Massachusetts, showing its utility for point-to-point wireless telephony, including interconnecting his stations to the wire telephone network. As part of the demonstration, speech was transmitted 18 kilometers (11 miles) to
12093-419: The late 1960s and 1970s, top 40 rock and roll stations in the U.S. and Canada such as WABC and CHUM transmitted highly processed and extended audio to 11 kHz, successfully attracting huge audiences. For young people, listening to AM broadcasts and participating in their music surveys and contests was the social media of the time. In the late 1970s, spurred by the exodus of musical programming to FM stations,
12232-455: The legs; hydraulic jacks were fitted to the shoes at the base of each leg, capable of exerting a force of 800 tonnes, and the legs were intentionally constructed at a slightly steeper angle than necessary, being supported by sandboxes on the scaffold. Although construction involved 300 on-site employees, due to Eiffel's safety precautions and the use of movable gangways, guardrails and screens, only one person died. The main structural work
12371-484: The licenses the same day. This article about a radio station in Texas is a stub . You can help Misplaced Pages by expanding it . AM broadcasting The earliest experimental AM transmissions began in the early 1900s. However, widespread AM broadcasting was not established until the 1920s, following the development of vacuum tube receivers and transmitters. AM radio remained the dominant method of broadcasting for
12510-399: The marketplace decide" which was best. The lack of a common standard resulted in consumer confusion and increased the complexity and cost of producing AM stereo receivers. In 1993, the FCC again revised its policy, by selecting C-QUAM as the sole AM stereo implementation. In 1993, the FCC also endorsed, although it did not make mandatory, AMAX broadcasting standards that were developed by
12649-432: The message, spreading it broadcast to receivers in all directions". However, it was recognized that this would involve significant financial issues, as that same year The Electrician also commented "did not Prof. Lodge forget that no one wants to pay for shouting to the world on a system by which it would be impossible to prevent non-subscribers from benefiting gratuitously?" On January 1, 1902, Nathan Stubblefield gave
12788-454: The middle of Paris. At this stage, a small "creeper" crane designed to move up the tower was installed in each leg. They made use of the guides for the lifts which were to be fitted in the four legs. The critical stage of joining the legs at the first level was completed by the end of March 1888. Although the metalwork had been prepared with the utmost attention to detail, provision had been made to carry out small adjustments to precisely align
12927-448: The multiple incompatible AM stereo systems, and failure of the manufacturers (including the auto makers) to effectively promote AMAX radios, coupled with the ever-increasing background of noise in the band, the general public soon lost interest and moved on to other media. On June 8, 1988, an International Telecommunication Union (ITU)-sponsored conference held at Rio de Janeiro, Brazil adopted provisions, effective July 1, 1990, to extend
13066-537: The necessity of having to transmit a high power carrier wave to overcome ground losses, and the large antenna radiators required at the low broadcast frequencies, but can be sent over long distances via the ionosphere at night; however, they are much more susceptible to interference, and often have lower audio fidelity. Thus, AM broadcasters tend to specialize in spoken-word formats, such as talk radio , all-news radio and sports radio , with music formats primarily for FM and digital stations. People who weren't around in
13205-405: The new frequencies. It was now estimated that the expanded band could accommodate around 300 U.S. stations. However, it turned out that the number of possible station reassignments was much lower, with a 2006 accounting reporting that, out of 4,758 licensed U.S. AM stations, only 56 were now operating on the expanded band. Moreover, despite an initial requirement that by the end of five years either
13344-428: The new policy, by 2011 there were approximately 500 in operation, and as of 2020 approximately 2,800 of the 4,570 licensed AM stations were rebroadcasting on one or more FM translators. In 2009 the FCC stated that "We do not intend to allow these cross-service translators to be used as surrogates for FM stations". However, based on station slogans, especially in the case of recently adopted musical formats, in most cases
13483-537: The next 30 years, a period called the " Golden Age of Radio ", until television broadcasting became widespread in the 1950s and received much of the programming previously carried by radio. Later, AM radio's audiences declined greatly due to competition from FM ( frequency modulation ) radio, Digital Audio Broadcasting (DAB), satellite radio , HD (digital) radio , Internet radio , music streaming services , and podcasting . Compared to FM or digital transmissions , AM transmissions are more expensive to transmit due to
13622-642: The order. On 25 August, before the Germans had been driven out of Paris , the German flag was replaced with a Tricolour by two men from the French Naval Museum , who narrowly beat three men led by Lucien Sarniguet, who had lowered the Tricolour on 13 June 1940 when Paris fell to the Germans. A fire started in the television transmitter on 3 January 1956, damaging the top of the tower. Repairs took
13761-411: The original station or its expanded band counterpart had to cease broadcasting, as of 2015 there were 25 cases where the original standard band station was still on the air, despite also operating as an expanded band station. HD Radio is a digital audio broadcasting method developed by iBiquity . In 2002 its "hybrid mode", which simultaneously transmits a standard analog signal as well as a digital one,
13900-424: The original water hydraulics were retained solely as a counterbalance system. A service lift was added to the south pillar for moving small loads and maintenance personnel three years later. Robert Moriarty flew a Beechcraft Bonanza under the tower on 31 March 1984. In 1987, A. J. Hackett made one of his first bungee jumps from the top of the Eiffel Tower, using a special cord he had helped develop. Hackett
14039-437: The other building blocks of an independent country." The proposed tower had been a subject of controversy, drawing criticism from those who did not believe it was feasible and those who objected on artistic grounds. Prior to the Eiffel Tower's construction, no structure had ever been constructed to a height of 300 m, or even 200 m for that matter, and many people believed it was impossible. These objections were an expression of
14178-433: The overheating issues of needing to insert microphones directly in the transmission antenna circuit. Vacuum tube transmitters also provided high-quality AM signals, and could operate on higher transmitting frequencies than alternator and arc transmitters. Non-governmental radio transmissions were prohibited in many countries during World War I, but AM radiotelephony technology advanced greatly due to wartime research, and after
14317-420: The position of rivet holes was specified to within 1 mm (0.04 in) and angles worked out to one second of arc . The finished components, some already riveted together into sub-assemblies, arrived on horse-drawn carts from a factory in the nearby Parisian suburb of Levallois-Perret and were first bolted together, with the bolts being replaced with rivets as construction progressed. No drilling or shaping
14456-441: The primary early developer of AM technology is Canadian-born inventor Reginald Fessenden . The original spark-gap radio transmitters were impractical for transmitting audio, since they produced discontinuous pulses known as " damped waves ". Fessenden realized that what was needed was a new type of radio transmitter that produced steady "undamped" (better known as " continuous wave ") signals, which could then be "modulated" to reflect
14595-404: The public between November and March because the water in the hydraulic drive tended to freeze. The new cars operate in pairs, with one counterbalancing the other, and perform the journey in one stage, reducing the journey time from eight minutes to less than two minutes. At the same time, two new emergency staircases were installed, replacing the original spiral staircases. In 1983, the south pillar
14734-650: The reception of AM transmissions and hurt the listening experience, among other reasons. However the United States Congress has introduced a bill to require all vehicles sold in the US to have an AM receiver to receive emergency broadcasts. The FM broadcast band was established in 1941 in the United States, and at the time some suggested that the AM band would soon be eliminated. In 1948 wide-band FM's inventor, Edwin H. Armstrong , predicted that "The broadcasters will set up FM stations which will parallel, carry
14873-799: The same deficiencies. The lack of any means to amplify electrical currents meant that, like the alternator transmitters, modulation was usually accomplished by a microphone inserted directly in the antenna wire, which again resulted in overheating issues, even with the use of water-cooled microphones. Thus, transmitter powers tended to be limited. The arc was also somewhat unstable, which reduced audio quality. Experimenters who used arc transmitters for their radiotelephone research included Ernst Ruhmer , Quirino Majorana , Charles "Doc" Herrold , and Lee de Forest . Advances in vacuum tube technology (called "valves" in British usage), especially after around 1915, revolutionized radio technology. Vacuum tube devices could be used to amplify electrical currents, which overcame
15012-400: The same program, as over their AM stations... eventually the day will come, of course, when we will no longer have to build receivers capable of receiving both types of transmission, and then the AM transmitters will disappear." However, FM stations actually struggled for many decades, and it was not until 1978 that FM listenership surpassed that of AM stations. Since then the AM band's share of
15151-410: The sounds being transmitted. Fessenden's basic approach was disclosed in U.S. Patent 706,737, which he applied for on May 29, 1901, and was issued the next year. It called for the use of 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,
15290-426: The structure were melted down, it would fill the square base, 125 metres (410 ft) on each side, to a depth of only 6.25 cm (2.46 in) assuming the density of the metal to be 7.8 tonnes per cubic metre. Additionally, a cubic box surrounding the tower (324 m × 125 m × 125 m) would contain 6,200 tonnes of air, weighing almost as much as the iron itself. Depending on
15429-413: The tabloid press. Multiple famous artists of that time, Charles Garnier and Alexander Dumas , thought poorly of the newly made tower. Charles Garnier thought it was a "truly tragic street lamp". Alexander Dumas said that it was like "Odius shadow of the odious column built of rivets and iron plates extending like a black blot". There were multiple protests over the style and the reasoning of placing it in
15568-411: The technology for AM broadcasting in stereo was challenging due to the need to limit the transmissions to a 20 kHz bandwidth, while also making the transmissions backward compatible with existing non-stereo receivers. In 1990, the FCC authorized an AM stereo standard developed by Magnavox, but two years later revised its decision to instead approve four competing implementations, saying it would "let
15707-509: The top and bottom of the tower. He found more at the top than expected, incidentally discovering what are known today as cosmic rays . Two years later, on 4 February 1912, Austrian tailor Franz Reichelt died after jumping from the first level of the tower (a height of 57 m) to demonstrate his parachute design. In 1914, at the outbreak of World War I , a radio transmitter located in the tower jammed German radio communications, seriously hindering their advance on Paris and contributing to
15846-482: The tower lost the title of the world's tallest structure when the Chrysler Building in New York City was completed. In 1938, the decorative arcade around the first level was removed. Upon the German occupation of Paris in 1940, the lift cables were cut by the French. The tower was restricted to German visitors during the occupation and the lifts were not repaired until 1946. In 1940, German soldiers had to climb
15985-444: The tower to be dismantled and temporarily relocated to Montreal to serve as a landmark and tourist attraction during Expo 67 . The plan was allegedly vetoed by the company operating the tower out of fear that the French government could refuse permission for the tower to be restored in its original location. In 1982, the original lifts between the second and third levels were replaced after 97 years in service. These had been closed to
16124-480: The tower to hoist a swastika-centered Reichskriegsflagge , but the flag was so large it blew away just a few hours later, and was replaced by a smaller one. When visiting Paris, Hitler chose to stay on the ground. When the Allies were nearing Paris in August 1944, Hitler ordered General Dietrich von Choltitz , the military governor of Paris, to demolish the tower along with the rest of the city. Von Choltitz disobeyed
16263-481: The tower to perform experiments on the action of air resistance on falling bodies. Eiffel had a permit for the tower to stand for 20 years. It was to be dismantled in 1909, when its ownership would revert to the City of Paris . The city had planned to tear it down (part of the original contest rules for designing a tower was that it should be easy to dismantle) but as the tower proved to be valuable for many innovations in
16402-417: The tower was built; others remained unconvinced. Guy de Maupassant supposedly ate lunch in the tower's restaurant every day because it was the one place in Paris where the tower was not visible. By 1918, it had become a symbol of Paris and of France after Guillaume Apollinaire wrote a nationalist poem in the shape of the tower (a calligram ) to express his feelings about the war against Germany. Today, it
16541-430: The tower was not opened to the public until nine days after the opening of the exposition on 6 May; even then, the lifts had not been completed. The tower was an instant success with the public, and nearly 30,000 visitors made the 1,710-step climb to the top before the lifts entered service on 26 May. Tickets cost 2 francs for the first level, 3 for the second, and 5 for the top, with half-price admission on Sundays, and by
16680-430: The tower. During the last three minutes of the year, the lights were turned on starting from the base of the tower and continuing to the top to welcome 2000 with a huge fireworks show. An exhibition above a cafeteria on the first floor commemorates this event. The searchlights on top of the tower made it a beacon in Paris's night sky, and 20,000 flashing bulbs gave the tower a sparkly appearance for five minutes every hour on
16819-401: The translator stations are not permitted to originate programming when the "primary" AM station is broadcasting, they are permitted to do so during nighttime hours for AM stations licensed for daytime-only operation. Prior to the adoption of the new policy, as of March 18, 2009, the FCC had issued 215 Special Temporary Authority grants for FM translators relaying AM stations. After creation of
16958-406: The two engineers then asked Stephen Sauvestre , the head of the company's architectural department, to contribute to the design. Sauvestre added decorative arches to the base of the tower, a glass pavilion to the first level, and other embellishments. The new version gained Eiffel's support: he bought the rights to the patent on the design which Koechlin, Nouguier, and Sauvestre had taken out, and
17097-496: The upper end of the Region 2 AM broadcast band, by adding ten frequencies which spanned from 1610 kHz to 1700 kHz. At this time it was suggested that as many as 500 U.S. stations could be assigned to the new frequencies. On April 12, 1990, the FCC voted to begin the process of populating the expanded band, with the main priority being the reduction of interference on the existing AM band, by transferring selected stations to
17236-471: The very conditions which give strength also conform to the hidden rules of harmony? ... Now to what phenomenon did I have to give primary concern in designing the Tower? It was wind resistance. Well then! I hold that the curvature of the monument's four outer edges, which is as mathematical calculation dictated it should be ... will give a great impression of strength and beauty, for it will reveal to
17375-548: The war the availability of tubes sparked a great increase in the number of amateur radio stations experimenting with AM transmission of news or music. Vacuum tubes remained the central technology of radio for 40 years, until transistors began to dominate in the late 1950s, and are still used in the highest power broadcast transmitters. Unlike telegraph and telephone systems, which used completely different types of equipment, most radio receivers were equally suitable for both radiotelegraph and radiotelephone reception. In 1903 and 1904
17514-404: The youngest demographic groups. Among persons aged 12–24, AM accounts for only 4% of listening, while FM accounts for 96%. Among persons aged 25–34, AM accounts for only 9% of listening, while FM accounts for 91%. The median age of listeners to the AM band is 57 years old, a full generation older than the median age of FM listeners." In 2009, the FCC made a major regulatory change, when it adopted
17653-572: Was 15 kHz resulting in bandwidth of 30 kHz. Another common limitation on AM fidelity is the result of receiver design, although some efforts have been made to improve this, notably through the AMAX standards adopted in the United States. AM broadcasts are used on several frequency bands. The allocation of these bands is governed by the ITU 's Radio Regulations and, on the national level, by each country's telecommunications administration (the FCC in
17792-474: Was approved by the FCC for use by AM stations, initially only during daytime hours, due to concerns that during the night its wider bandwidth would cause unacceptable interference to stations on adjacent frequencies. In 2007 nighttime operation was also authorized. The number of hybrid mode AM stations is not exactly known, because the FCC does not keep track of the stations employing the system, and some authorized stations have later turned it off. But as of 2020
17931-556: Was arrested by the police. On 27 October 1991, Thierry Devaux, along with mountain guide Hervé Calvayrac, performed a series of acrobatic figures while bungee jumping from the second floor of the tower. Facing the Champ de Mars, Devaux used an electric winch between figures to go back up to the second floor. When firemen arrived, he stopped after the sixth jump. For its "Countdown to the Year 2000" celebration on 31 December 1999, flashing lights and high-powered searchlights were installed on
18070-475: Was assumed to have no gaps in the latticework. After it was completed, some have put forward various mathematical hypotheses in an attempt to explain the success of the design. A one devised in 2004 after letters sent by Eiffel to the French Society of Civil Engineers in 1885 were translated into English described it as a non-linear integral equation based on counteracting the wind pressure on any point of
18209-404: Was completed at the end of March 1889 and, on 31 March, Eiffel celebrated by leading a group of government officials, accompanied by representatives of the press, to the top of the tower. Because the lifts were not yet in operation, the ascent was made by foot, and took over an hour, with Eiffel stopping frequently to explain various features. Most of the party chose to stop at the lower levels, but
18348-409: Was constructed as the centerpiece of the 1889 World's Fair , and to crown the centennial anniversary of the French Revolution . Although initially criticised by some of France's leading artists and intellectuals for its design, it has since become a global cultural icon of France and one of the most recognisable structures in the world. The tower received 5,889,000 visitors in 2022. The Eiffel Tower
18487-516: Was done on site: if any part did not fit, it was sent back to the factory for alteration. In all, 18,038 pieces were joined using 2.5 million rivets. At first, the legs were constructed as cantilevers , but about halfway to the first level construction was paused to create a substantial timber scaffold . This renewed concerns about the structural integrity of the tower, and sensational headlines such as "Eiffel Suicide!" and "Gustave Eiffel Has Gone Mad: He Has Been Confined in an Asylum" appeared in
18626-467: Was fitted with an electrically driven Otis lift to serve the Jules Verne restaurant. The Fives-Lille lifts in the east and west legs, fitted in 1899, were extensively refurbished in 1986. The cars were replaced, and a computer system was installed to completely automate the lifts. The motive power was moved from the water hydraulic system to a new electrically driven oil-filled hydraulic system, and
18765-400: Was immediately recognized that, much like the telegraph had preceded the invention of the telephone, the ability to make audio radio transmissions would be a significant technical advance. Despite this knowledge, it still took two decades to perfect the technology needed to make quality audio transmissions. In addition, the telephone had rarely been used for distributing entertainment, outside of
18904-472: Was installed. On two separate but related occasions in 1925, the con artist Victor Lustig "sold" the tower for scrap metal. A year later, in February 1926, pilot Leon Collet was killed trying to fly under the tower. His aircraft became entangled in an aerial belonging to a wireless station. A bust of Gustave Eiffel by Antoine Bourdelle was unveiled at the base of the north leg on 2 May 1929. In 1930,
19043-458: Was modified, with the space available for visitors on the second level. The original lift in the south pillar was removed 13 years later. On 19 October 1901, Alberto Santos-Dumont , flying his No.6 airship , won a 100,000-franc prize offered by Henri Deutsch de la Meurthe for the first person to make a flight from St. Cloud to the Eiffel Tower and back in less than half an hour. In 1910, Father Theodor Wulf measured radiant energy at
19182-473: Was the first organization to create a radio network, and also to promote commercial advertising, which it called "toll" broadcasting. Its flagship station, WEAF (now WFAN) in New York City, sold blocks of airtime to commercial sponsors that developed entertainment shows containing commercial messages . AT&T held a monopoly on quality telephone lines, and by 1924 had linked 12 stations in Eastern cities into
19321-406: Was the lack of amplifying the signals, so listeners had to use earphones , and it required the development of vacuum-tube receivers before loudspeakers could be used. The dynamic cone loudspeaker , invented in 1924, greatly improved audio frequency response over the previous horn speakers, allowing music to be reproduced with good fidelity. AM radio offered the highest sound quality available in
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