AM broadcasting - Knowledge

439:(referred to as "an alternating-current dynamo") that generated "pure sine waves" and produced "a continuous train of radiant waves of substantially uniform strength", or, in modern terminology, a continuous-wave (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 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 the characteristics of 559: 487:

the words of a handout distributed to the demonstration witnesses, which stated " 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 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.

479:, 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 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 a listening site at Plymouth, Massachusetts. 773: 1327:

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 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".

663:). The intended audience for both transmissions was primarily shipboard radio operators along the Atlantic seaboard. Fessenden claimed these two programs had been widely publicized in advance, with the Christmas Eve broadcast heard "as far down" as Norfolk, Virginia, while the New Year’s Eve broadcast had been received in the West Indies. However, extensive efforts to verify Fessenden's claim during both the 50th and 100th anniversaries of the claimed broadcasts, which included reviewing ships' radio log accounts and other contemporary sources, have so far failed to confirm that these reported holiday broadcasts actually took place. 1637:. On mediumwave these stations often transmit on 1610 kHz to 1710 kHz. Hobbyists also use low-power AM (LPAM) transmitters to provide programming for vintage radio equipment in areas where AM programming is not widely available or does not carry programming the listener desires; in such cases the transmitter, which is designed to cover only the immediate property and perhaps nearby areas, is connected to a computer, an FM radio or an MP3 player. Microbroadcasting and pirate radio have generally been supplanted by streaming audio on the Internet, but some schools and hobbyists still use LPAM transmissions. 1043: 781: 397: 306: 655:'s series of demonstration broadcasts begun in 1907 were the first transmissions of music and entertainment by radio. However, in 1932 an article prepared by Samuel M. Kintner, a former associate of Reginald Fessenden, asserted that Fessenden had actually conducted two earlier broadcasts. This claim was based solely on information included in a January 29, 1932, letter that Fessenden had sent to Kintner. (Fessenden subsequently died five months before Kintner's article appeared.) In his letter, Fessenden reported that, on the evening of December 24, 1906 ( 546:

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 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

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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 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.

931: 1166:, predicted that "The broadcasters will set up FM stations which will parallel, carry 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 the audience has continued to decline. 298: 386: 789:

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:

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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

405: 200:, AM transmissions are more expensive to transmit due to 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 1000: 1154:(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 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. 1244:

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 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.

741:. This transmission was heard throughout much of Europe, including in Berlin, Paris, The Hague, Madrid, Spain, and Sweden. Chelmsford continued broadcasting concerts with noted performers. A few months later, in spite of burgeoning popularity, the government ended the broadcasts, due to complaints that the station's longwave signal was interfering with more important communication, in particular military aircraft radio. 4912: 659:), he had made the first of two broadcasts of music and entertainment to a general audience, using the alternator-transmitter at Brant Rock, Massachusetts. Fessenden remembered producing a short program that included playing a phonograph record, followed by his playing the violin and singing, and closing with a Bible reading. He also stated that a second short program was broadcast on December 31 ( 4922: 1502:(MF)), is by far the most commonly used AM broadcasting band. In ITU Regions 1 and 3, transmitting frequencies run from 531 kHz – 1602 kHz, with 9 kHz spacing (526.5 kHz – 1606.5 kHz), and in ITU Region 2 (the Americas), transmitting frequencies are 530 kHz – 1700 kHz, using 10 kHz spacing (525 kHz – 1705 kHz), including the ITU 1296:

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 is comparable to or better in audio quality than a standard analog broadcast".

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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 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.

1282: 4901: 1292:. In 2002 its "hybrid mode", which simultaneously transmits a standard analog signal as well as a digital one, 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. 721:"University of Wisconsin electrical engineering Professor Edward Bennett sets up a personal radio transmitter on campus and in June 1915 is issued an Experimental radio station license with the call sign 9XM. Activities included regular Morse Code broadcasts of weather forecasts and sending game reports for a Wisconsin-Ohio State basketball game on February 17, 1917. 1008:

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 a consortium, the

4932: 1368:, 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. 1139:, however overall there was limited adoption of AM stereo worldwide, and interest declined after 1990. With 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. 1012:(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 1319:

almost non-existent to 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."

1311: 1523:(HF)) transmissions range from approximately 2.3 to 26.1 MHz, divided into 14 broadcast bands. Shortwave broadcasts generally use a narrow 5 kHz channel spacing. Shortwave is used by audio services intended to be heard at great distances from the transmitting station. The long range of shortwave broadcasts comes at the expense of lower 1400:) 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 a result, AM radio tends to do best in areas where 1263:(ITU)-sponsored conference held at Rio de Janeiro, Brazil adopted provisions, effective July 1, 1990, to extend 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. 893:(later WWJ), located in the newspaper's headquarters building. The newspaper began extensively publicizing station operations beginning on August 31, 1920, with a special program featuring primary election returns. Station management later claimed the title of being where "commercial radio broadcasting began". 1318:

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

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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 the new frequencies. It was now estimated that the expanded band could accommodate around 300

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Initially the consumer manufacturers made 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

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Argentina made the first mass radio transmission as a communication medium. Medicine students of the UBA made the first radio program by transmitting Wagner's Parsifal on radio and picked up by about 100 amateurs in the city, emitting from the roof of the Teatro Colón. They kept transmitting over the

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in 1948. (The transistor was invented at Bell labs and released in June 1948.) Their compact size — small enough to fit in 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

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Beginning in the mid-1930s, the United States evaluated options for the establishment of broadcasting stations using much higher transmitting frequencies. In October 1937, the FCC announced a second band of AM stations, consisting of 75 channels spanning from 41.02 to 43.98 MHz, which

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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

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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 the marketplace decide" which was best. The lack of a common standard resulted in consumer confusion and increased

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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

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The first person to transmit entertainment broadcasts on a regular schedule appears to have been Charles "Doc" Herrold, who inaugurated weekly programs, using an arc transmitter, from his Wireless School station in San Jose, California. The broadcasts continued until the station was shut down due to

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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 the same deficiencies. The lack of

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began broadcasting recorded and live music on a semi-regular schedule from his home station, 8XK in Wilkinsburg, Pennsylvania. This inspired his employer to begin its own ambitious service at the company's headquarters in East Pittsburgh, Pennsylvania. Operations began, initially with the call sign

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at The Hague, which began regular concerts broadcasts. It found it had a large audience outside the Netherlands, mostly in the UK. (Rather than true AM signals, at least initially this station used a form of narrowband FM, which required receivers to be slightly detuned to receive the signals using

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in Belgium, under the oversight of Robert Goldschmidt, inaugurated a weekly series of concerts, transmitted at 5:00 p.m. on Saturdays. These continued for about four months until July, and were ended by the start of World War I. In August 1914 the Laeken facilities were destroyed, to keep them

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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

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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 the overheating issues of needing to insert microphones directly in the transmission antenna circuit. Vacuum

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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

1607:, and can be used alongside many AM broadcasts. Both of these standards are capable of broadcasting audio of significantly greater fidelity than that of standard AM with current bandwidth limitations, and a theoretical frequency response of 0–16 kHz, in addition to stereo sound and text data. 1184:

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

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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

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When broadcasting began in 1920, music was played on air without regard to its copyright status. Music publishers challenged this practice as being copyright infringement, which for a time kept many popular tunes off the air, and this 1925 U.S. editorial cartoon shows a rich publisher muzzling two

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The ongoing development of alternative transmission systems, including Digital Audio Broadcasting (DAB), satellite radio, and HD (digital) radio, continued the decline of the popularity of the traditional broadcast technologies. These new options, including the introduction of Internet streaming,

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Because most longwave radio frequencies were used for international radiotelegraph communication, 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

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It 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

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were received throughout much of Europe. In both 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

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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 the commission estimated that fewer than 250 AM stations were transmitting hybrid mode

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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 the decades, to the point that the value of land exceeds that of the station

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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 the British public pressured the government to reintroduce the service,

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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 the new policy, by 2011 there were approximately 500 in operation, and as of 2020 approximately 2,800 of the 4,570

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In 2009, the FCC made a major regulatory change, when it adopted 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

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In 1961, the FCC adopted a single standard for FM stereo transmissions, which was widely credited with enhancing FM's popularity. Developing 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

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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 the first time. Music came

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In a June 23, 1910, notarized letter that was published in a catalog produced by the Electro Importing Company of New York, Charles "Doc" Herrold reported that, using one of that company's spark coils to create a "high frequency spark" transmitter, he had successfully broadcast "wireless phone

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In 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

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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 a central station to all parts of the United States", he was unable to

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inserted directly in 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

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The 40 kHz spacing between adjacent frequencies was four times that of the 10 kHz spacing used on the standard AM broadcast band, which reduced adjacent-frequency interference, and provided more bandwidth for high-fidelity programming. However, this band was eliminated effective

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University of Wisconsin - Regular schedule of voice broadcasts begin; 9XM is the first radio station in the United States to provide the weather forecast by voice (January 3). In September, farm market broadcasts are added. On November 1, 9XM carries the first live broadcast of a symphony

1239:(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 317:

The idea of broadcasting — the unrestricted transmission of signals to 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

1135:. 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 669:

Lee de Forest conducted multiple test broadcasts beginning in 1907, and was widely quoted promoting the potential of organized radio broadcasting. Using a series of arc transmitters, he made his first entertainment broadcast in February 1907, transmitting electronic

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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 the

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De Forest's New York station, 2XG, returned to the airwaves in late 1919 after having to suspend operations during World War I. The station continued to operate until early 1920, when it was shut down because the transmitter had been moved to a new location without

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was developed, and mostly adopted on U.S. college campuses. In this approach AM broadcast signals are distributed over electric power lines, which radiate a signal receivable at a short distance from the lines. In Switzerland a system known as "wire broadcasting"

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The demarcation between what is considered "experimental" and "organized" broadcasting 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":

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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.

459:), 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 834:

Shortly after the end of World War I, F. S. McCullough at the Glenn L. Martin aviation plant in Cleveland, Ohio, began a weekly series of phonograph concerts. However, the broadcasts were soon suspended, due to interference complaints by the U.S.

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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

1119:, 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 818:. This station also suspended operations in April 1917 due to the prohibition of civilian radio transmissions following the United States' entry into World War I. Its most publicized program was the broadcasting of election results for the 467:

signal to produce AM audio transmissions. However, it would take many years of expensive development before even a prototype alternator-transmitter would be ready, and a few years beyond that for high-power versions to become available.

1478:(Europe, Africa, and northern and central Asia) and are not allocated elsewhere. Individual stations have coverage measured in the hundreds of kilometers; however, there is only a very limited number of available broadcasting slots. 1474:– 283.5 kHz) Broadcasting stations in this band are assigned transmitting frequencies in the range 153 kHz – 279 kHz, and generally maintain 9 kHz spacing. Longwave assignments for broadcasting only exist in 979:(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 334:

once expressed it, it might be advantageous to 'shout' 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

1189:'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. 877:, the "California Theater station". By June 1920 the station began transmitting daily concerts. De Forest later stated that this was the "first radio-telephone station devoted solely" to broadcasting to the public. 499:

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.

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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 the

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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.

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gave a short-range "wireless telephone" demonstration, that included simultaneously broadcasting speech and music to seven locations throughout Murray, Kentucky. However, this was transmitted using

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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?"

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spread rapidly during the next 15 years, providing ready audiences for the first radio broadcasts. One limitation of crystals sets was the lack of amplifying the signals, so listeners had to use

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over the previous horn speakers, allowing music to be reproduced with good fidelity. AM radio offered the highest sound quality available in a home audio device prior to the introduction of the

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De Forest perfected "Oscillion" power vacuum tubes, capable of use in radio transmitters, and inaugurated daily broadcasts of entertainment and news from his New York "Highbridge" station,

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1938 Zenith Model 12-S vacuum-tube console radio, capable of picking up mediumwave and shortwave AM transmissions. "All Wave" receivers could also pick up the third AM band: longwave (LW).

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Farmer listening to U.S. government weather and crop reports using a crystal radio in 1923. Public service government time, weather, and farm broadcasts were the first radio "broadcasts".

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Radio greatly eased 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

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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.

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with experimental arc radiotelephones for their 1908 around-the-world cruise, and the operators broadcast phonograph music as the ships entered ports like San Francisco and Honolulu.

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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

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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,

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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

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The earliest experimental AM transmissions began in the early 1900s. However, widespread AM broadcasting was not established until the 1920s, following the development of

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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 (

2426: 955:(AT&T) was the first organization to create a radio network, and also to promote commercial advertising, which it called "toll" broadcasting. Its flagship station, 1591:

Hybrid digital broadcast systems, which combine (mono analog) AM transmission with digital sidebands, have started to be used around the world. In the United States,

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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

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In the late 1970s, spurred by the exodus of musical programming to FM stations, the AM radio industry in the United States developed technology for broadcasting in

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Broadcasting in the United Kingdom began with impromptu news and phonograph music over 2MT, the 15 kW experimental tube transmitter at Marconi's factory in

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frequencies; however, complaints about interference from existing services, particularly the military, led to most broadcasting moving to higher frequencies.

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and, on the national level, by each country's telecommunications administration (the FCC in the U.S., for example) subject to international agreements.

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offices. An estimated 7,000 radio listeners as far as 200 miles (320 kilometers) from New York heard election returns interspersed with patriotic music.

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One of the earliest radio broadcasts, French soprano Mariette Mazarin singing into Lee de Forest's arc transmitter in New York City on February 24, 1910

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Lee de Forest used an early vacuum-tube transmitter to broadcast returns for the Hughes-Wilson presidential election returns on November 7, 1916, over

908:, the station adopted a daily schedule beginning on December 21, 1920. This station is another contender for the title of "first commercial station". 1690: 819: 1211:

Radios meeting the AMAX standards could display a certification logo, with the "stereo" notation reserved for those capable of AM stereo reception

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particularly resulted in the reduction of shortwave transmissions, as international broadcasters found ways to reach their audiences more easily.

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Broadcasting in Germany began 1922 as a Post Office monopoly on a subscription basis, using sealed receivers which could only receive one station.

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nights different operas being the first in offering a radio program. There were known as the "Locos de la azotea" (the crazies of the roof).

1236: 1721: 3127: 4868: 4714: 3829: 3653: 1344: 686:". Additional promotional events in New York included live performances by famous Metropolitan Opera stars such as Mariette Mazarin and 424:. The original spark-gap radio transmitters were impractical for transmitting audio, since they produced discontinuous pulses known as " 360:

ability to pick up time signal broadcasts, in addition to Morse code weather reports and news summaries, also attracted the interest of

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Many U.S. AM stations no longer publicize their AM signals, instead promoting simulcasts by FM band translators and Internet streams.

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A BBC receiver licence from 1922. The British government required listeners to purchase yearly licences, which financed the stations.

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network. By the 1930s, most of the major radio stations in the country were affiliated with networks owned by two companies, NBC and

4734: 3251: 2708: 2678: 972: 772: 216: 2007: 4519: 4067: 3869: 3285: 2607: 2458: 1413: 1013: 428:". Fessenden realized that what was needed was a new type of radio transmitter that produced steady "undamped" (better known as " 2548: 1042: 963:. AT&T held a monopoly on quality telephone lines, and by 1924 had linked 12 stations in Eastern cities into a "chain". The 4630: 2909:

Final Acts of the Regional Radio Conference to Establish a Plan for the Broadcasting Service in the Band 1605-1705 in Region 2

780: 243:(strength) of the carrier wave, proportional to the original signal. In contrast, in the case of FM, it is the carrier wave's 157:

receivers and transmitters. AM radio remained the dominant method of broadcasting for the next 30 years, a period called the "

4956: 4625: 4176: 3766: 2754: 1782: 1232: 1343:" stations. This would allow co-channel secondary stations to operate with higher powers, especially at night. However, the 934:

A live radio play being broadcast at NBC studios in New York. Most 1920s through 1940s network programs were broadcast live.

2766: 674:

music from his Parker Building laboratory station in New York City. This was followed by tests that included, in the fall,

4961: 4650: 3614: 2334: 1695: 1421: 1417: 980: 4935: 2937: 2813: 2121: 1420:

to 10.2 kHz, limiting occupied bandwidth to 20.4 kHz. The former audio limitation was 15 kHz resulting in

959:(now WFAN) in New York City, sold blocks of airtime to commercial sponsors that developed entertainment shows containing 841:

The first scheduled (pre-announced in the press) Dutch radio broadcast was made by Nederlandsche Radio Industrie station

4925: 4686: 4583: 4126: 3893: 3541: 1397: 1009: 984: 3088: 4915: 4422: 3862: 3839: 3278: 1829: 1412:

To allow room for more stations on the mediumwave broadcast band in the United States, in June 1989 the FCC adopted a

490:

Because there was no way to amplify electrical currents at this time, modulation was usually accomplished by a carbon

3073: 2862: 2650: 2580: 2273: 2019: 1995: 1909: 1865: 1797: 3100: 3074:"Report and Order: In the Matter of Amendment of Service and Eligibility Rules for FM Broadcast Translator Stations" 2953: 2248: 4774: 4696: 4635: 4342: 3812: 3781: 3526: 3436: 1531: 1447:

The frequency ranges given here are those that are allocated to stations. Because of the bandwidth taken up by the

1376:

AM radio technology is simpler than later transmission systems. An AM receiver detects amplitude variations in the

715:, near Brussels, Belgium, and by March 13, 1914, the tests had been heard as far away as the Eiffel Tower in Paris. 630:(Regency TR-1, the first transistor radio released December 1954), which was made possible by the invention of the 592: 396: 170: 443:. Fessenden attempted to sell this form of radiotelephone for point-to-point communication, but was unsuccessful. 4546: 4507: 4352: 4252: 4181: 4114: 3941: 2921: 2891: 2105: 1377: 683: 373:

transmissions. In addition, the telephone had rarely been used for distributing entertainment, outside of a few "

347: 3243:

Localist Movements in a Global Economy Sustainability, Justice, and Urban Development in the United StatesStates

4905: 4147: 4082: 4035: 3921: 2516: 2091: 1813: 1669: 2302: 930: 776:

In July 1912, Charles "Doc" Herrold began weekly broadcasts in San Jose, California, using an arc transmitter.

2966:"Mass Media Bureau Announces Revised AM Expanded Band Allotment Plan and Filing Window for Eligible Stations" 1991: 239:

of a specific frequency, then broadcast. In the case of AM, this mixing (modulation) is done by altering the

4744: 4729: 4573: 4524: 4447: 4347: 4025: 3911: 3906: 3791: 3690: 3643: 3551: 2979: 2318: 2162: 1305: 1207: 496: 265: 186: 162: 3061:, 1360 AM in Chapel Hill, North Carolina, whose publicized signal is over FM translator W250BP at 97.9 MHz. 412:

receiver in 1922. Crystal sets, used before the advent of vacuum tube radios in the 1920s, could not drive

297: 4666: 4452: 4267: 4212: 4207: 4020: 3985: 3685: 3599: 3441: 1646: 1616: 1600: 1506:, authorized in Region 2, between 1605 kHz and 1705 kHz, previously used for police radio. 1357: 1227:

as the sole AM stereo implementation. In 1993, the FCC also endorsed, although it did not make mandatory,

1163: 1025: 1021: 2965: 2194:(Wireless in the Belgian Congo and from the Laeken Training School to Radio Concerts) by Bruno Brasseur, 1076:. Radio news, including remote reporting, allowed listeners to be vicariously present at notable events. 1052:

entertainment such as oral storytelling and music from family members. New forms were created, including

4568: 4372: 4337: 4257: 4237: 4159: 4047: 3968: 3786: 3609: 3589: 2564: 1340: 873:

De Forest transferred 2XG's former transmitter to San Francisco, California, where it was relicensed as

568: 420:

The person generally credited as the primary early developer of AM technology is Canadian-born inventor

319: 2780: 2047: 2384: 1553:

1 January 1941, after the FCC determined that establishing a band of FM stations was preferable.

1185:

economically carried on a national scale. The introduction of nationwide talk shows, most prominently

4482: 4442: 4412: 4169: 4104: 3995: 3414: 3354: 3339: 3334: 3043: 3023: 1652: 988: 584: 550:

began to dominate in the late 1950s, and are still used in the highest power broadcast transmitters.

224: 220: 197: 135: 47: 1436:

AM broadcasts are used on several frequency bands. The allocation of these bands is governed by the

4492: 4432: 4191: 4153: 4010: 3951: 3936: 3521: 3392: 3000: 1037: 508:

Almost all of the continuous wave AM transmissions made prior to 1915 were made by versions of the

385: 374: 343: 158: 2355: 1947: 737:

newspaper sponsored the first scheduled British radio concert, by the famed Australian opera diva

4719: 4676: 4607: 4477: 4407: 4382: 4317: 4164: 3885: 3658: 2896:

Proceedings of the National Association of Broadcasters Engineering Conference, Las Vegas, Nevada

2219: 1571:" at Brown University in Providence, Rhode Island, a very low power broadcasting method known as 1530:

Most broadcast services use AM transmissions, although some use a modified version of AM such as

1132: 1080: 804: 712: 612: 580: 476: 421: 131: 91: 1897: 1451:, the range allocated for the band as a whole is usually about 5 kHz wider on either side. 1409:" means that the dominant signal needs to only be about twice as strong as the interfering one. 1347:(FEMA) expressed concerns that this would reduce the effectiveness of emergency communications. 1073: 4759: 4681: 4595: 4578: 4541: 4427: 4387: 4217: 4186: 4052: 3946: 3771: 3648: 3247: 2788: 2704: 2674: 2631: 2500: 2442: 1881: 1778: 1634: 1622: 1545: 1441: 1401: 1361: 1181: 1175: 824: 695: 660: 460: 404: 2698: 2668: 1845: 1772: 1746: 392:

making a broadcast over the Marconi Chelmsford Works radio station in England on 15 June 1920

4764: 4724: 4704: 4671: 4600: 4558: 4472: 4327: 4312: 4287: 4262: 4222: 4072: 3931: 3926: 3916: 3807: 3751: 3565: 3376: 3301: 2625: 1680: 1675: 1503: 1499: 1254: 1151: 1088: 1069: 1017: 968: 960: 847: 679: 627: 588: 572: 522: 513: 472: 261: 2865:(January 15, 1948), "Restrictive union practices of the American Federation of Musicians", 999: 4392: 4247: 4015: 3978: 3776: 3382: 3145: 2192:"De la T.S.F. au Congo-Belge et de l'école pratique de Laeken aux concerts radiophoniques" 1604: 1572: 1562: 1112: 526: 429: 272: 174: 166: 147: 35: 31: 3990: 2907: 2726: 915:

orchestra—the Cincinnati Symphony Orchestra from the UW Armory using a single microphone.

3270: 2065: 4590: 4462: 4437: 4397: 4367: 4242: 4077: 3963: 3386: 2038:

U.S. patent 789,449, filed June 10, 1903, and granted May 9, 1905, to Valdemar Poulsen.

1520: 1406: 1365: 1084: 904:

8ZZ, with an election night program featuring election returns on November 2, 1920. As

675: 378: 205: 182: 4950: 4739: 4512: 4502: 4417: 4307: 4302: 4292: 4277: 4099: 3958: 3761: 3486: 3366: 3305: 2984: 1524: 1467: 1186: 940: 925: 687: 656: 652: 616: 596: 576: 530: 509: 440: 432:") signals, which could then be "modulated" to reflect the sounds being transmitted. 409: 361: 3019:"Proposed rule: All-digital AM broadcasting, revitalization of the AM radio service" 2236:

The History of Broadcasting in the United Kingdom: Vol. I: The Birth of Broadcasting

4617: 4457: 4402: 4332: 4297: 4232: 4131: 4121: 3973: 3833: 3308: 1630: 1392:. However, the simplicity of AM transmission also makes it vulnerable to "static" ( 1120: 1065: 943:, linking stations together with telephone lines to provide a nationwide audience. 900: 885: 738: 691: 671: 626:

Listening habits changed in the 1960s due to the introduction of the revolutionary

620: 518: 464: 389: 377:" systems, most of which were established in Europe. With this in mind, most early 356: 331: 248: 236: 232: 209: 3206: 3177: 1633:

operators on mediumwave and shortwave, achieve greater range than possible on the

3241: 3039:"Final rule: All-digital AM broadcasting, revitalization of the AM radio service" 1774:

The Science of Radio: With Matlab and Electronics Workbench Demonstration, 2nd Ed

4817: 4467: 4377: 4362: 4322: 4282: 4141: 3756: 3581: 3372: 3227: 2596: 2207: 1585: 1534:(SSB) or an AM-compatible version of SSB such as "SSB with carrier reinserted". 1494: 1393: 1385: 1047:

radio performers. The radio industry eventually agreed to make royalty payments.

608: 604: 542: 425: 413: 154: 139: 2163:"Mysterious Voices Startled Him: Wizard Isbell Thought He Heard Angels Talking" 1660:, a digital system for adding low bitrate information to an AM broadcast signal 705:

concerts to local amateur wireless men". Herrold lived in San Jose, California.

4822: 4529: 4227: 4136: 4092: 4062: 4040: 4030: 4005: 3638: 3624: 3326: 2341:, 25 April 1934, p. 17 (reprinted from the British Broadcasting Corporation's 1599:

has been adopted and approved by the FCC for medium wave transmissions, while

1475: 1116: 1092: 1057: 1053: 764: 733: 728: 631: 547: 491: 452: 436: 323: 284: 228: 201: 190: 2792: 2627:

Network Nations: A Transnational History of British and American Broadcasting

231:(coding). The electrical signal from program material, usually coming from a 4807: 4272: 4087: 3730: 3725: 3720: 3710: 3701: 3560: 3058: 1900:, submitted May 29, 1901, and issued August 12, 1902, to Reginald Fessenden. 1515: 1471: 1198: 1136: 1100: 1061: 976: 956: 905: 815: 711:

Robert Goldschmidt began experimental radiotelephone transmissions from the

310: 244: 240: 2839:"Congress wants AM radio in all new cars—trade groups say that's a mistake" 2036:"Method of Producing Alternating Currents With a High Number of Vibrations" 1649:(DRM), a digital radio method using the bands LW, MW, SW, and the VHF bands 1703:, the hobby of receiving distant AM radio stations on the mediumwave band. 1281: 4802: 4792: 4709: 4534: 4357: 3451: 3404: 3362: 1596: 1592: 1581: 1482: 1462: 1448: 1389: 1336: 1289: 1276: 1150:

In 2022 it was reported that AM radio was being removed from a number of

890: 759:

pouring in. Laughter came in. News came in. The world shrank, with radio.

600: 279:

pouring in. Laughter came in. News came in. The world shrank, with radio.

178: 143: 2879: 455:, which normally produced alternating current of at most a few hundred ( 215: 17: 4797: 4782: 3491: 3446: 3400: 1626: 1381: 1096: 952: 110: 1339:, proposed greatly reducing signal protection for 50 kW Class A " 1310: 1216:

transmissions backward compatible with existing non-stereo receivers.

4827: 4787: 4109: 3901: 3854: 3715: 3531: 3505: 3500: 3459: 3410: 3396: 1224: 975:

organized a competing network around its own flagship station, RCA's

2781:"In a Future Filled With Electric Cars, AM Radio May Be Left Behind" 4812: 4749: 4057: 3536: 3431: 3323: 2814:"Automakers Are Starting to Drop AM Radio in New Cars. Here's Why" 2249:"La Verdadera Historia de los Locos de la Azotea – Radio Nacional" 1700: 1663: 1625:, especially those in the United States operating under the FCC's 1280: 1206: 1041: 1020:

fee. Both highbrow and mass-appeal programmes were carried by the

929: 779: 771: 603:, and it required the development of vacuum-tube receivers before 557: 456: 403: 395: 384: 304: 296: 3076:(MB Docket Mo. 07-172, RM-11338), June 29, 2009, pages 9642–9660. 1360:(EAS). Some automakers have been eliminating AM radio from their 797:

the entrance of the United States into World War I in April 1917.

4754: 3167:

Federal Communications Commission rules (Report). 47 CFR §2.106.

2366:(27). Chicago: Telephony Publishing Co.: 32–33 December 30, 1916 1955: 1568: 1425: 1380:

at a particular frequency, then amplifies changes in the signal

1228: 1202: 864: 842: 3858: 3671: 3274: 3240:

David J. Hess; Professor David J Hess; Robert Gottlieb (2009).

1986:"Experiments and Results in Wireless Telephony" by John Grant, 731:, Essex, at a frequency of 120 kHz. On June 15, 1920, the 351:

overcome the inherent distance limitations of this technology.

4000: 2867:

United States Congress, House Committee on Education and Labor

2024:

Transactions of the American Institute of Electrical Engineers

1580:

in German) transmitted AM signals over telephone lines in the

1095:

as a powerful government tool, and contributed to the rise of

964: 874: 1288:

HD Radio is a digital audio broadcasting method developed by

1016:. an independent nonprofit supported solely by a 10 shilling 247:

that is varied. A radio receiver contains a demodulator that

1481:

Most of the earliest broadcasting experiments took place on

1405:

reduction in quality, in contrast to FM signals, where the "

822:

on November 7, 1916, with updates provided by wire from the

212:, with music formats primarily for FM and digital stations. 2149:"I Was First to Sing Over the Radio" by Eugenia H. Farrar, 2068:. New York : Murry Hill – via Internet Archive. 1220:

the complexity and cost of producing AM stereo receivers.

591:, the simplest and cheapest AM detector, was developed by 30:"AM radio" redirects here. For the song by Everclear, see 1777:. Springer Science & Business Media. pp. xxxix. 142:(also known as "AM band") transmissions, but also on the 2078:"Pittsburgh's Contributions to Radio" by S. M. Kintner, 1830:"Kentucky Inventor Solves Problem of Wireless Telephony" 1223:

In 1993, the FCC again revised its policy, by selecting

368:

Early amplitude modulation (AM) transmitter technologies

3128:"Proposed Rule: Revitalization of the AM Radio Service" 2882:

Fybush.com. February 17, 2021. Retrieved July 10, 2024.

2010:

by James E. O'Neal, December 22, 2016 (radioworld.com).

1672:(ERP), standardised definition of radio frequency power 1416:(NRSC) standard that limited maximum transmitted audio 1091:. However, broadcasting also provided the means to use 313:

in New York City. Pictured is engineer Charles Logwood.

251:

the original program material from the broadcast wave.

2178:

Electro Importing Company catalog page, reproduced in

939:

method for sharing program costs, was to create radio

808:

from falling into the hands of invading German troops.

651:

Until the early 1930s, it was generally accepted that

2956:

by Randy J. Stine, February 28, 2006 (radioworld.com)

2938:"FCC Votes To Proceed With AM-Band Improvement Plans" 2757:

by Lance Venta, February 11, 2021 (radioinsight.com).

2487:"Electrical Home Visitors to Hear Wireless Concert", 2385:"Election Returns Flashed by Radio to 7,000 Amateurs" 1588:

was an early pioneer of AM radio cable distribution.

991:, was formed as a cooperative owned by its stations. 899:

Beginning on October 17, 1919, Westinghouse engineer

3146:"Scoop: Congress moves to preserve AM radio in cars" 2608:"Announcing the National Broadcasting Company, Inc." 2539:, August 20, 1945, p. 31. (americanradiohistory.com) 1686:

List of 50 kW AM radio stations in the United States

4836: 4773: 4695: 4659: 4616: 4557: 4491: 4200: 3892: 3800: 3739: 3699: 3678: 3623: 3580: 3550: 3514: 3479: 3472: 3424: 3353: 3322: 3315: 3178:"America's Apex Broadcasting Stations of the 1930s" 3118:

by Randy J. Stine, October 5, 2020 (radioworld.com)

1666:, a hybrid digital radio format for AM broadcasting 1584:band until 1998, when it was shut down. In the UK, 1158:

AM band revitalization efforts in the United States

512:transmitter, which had been initially developed by 105: 97: 87: 69: 61: 53: 3103:by Randy J. Stine, August 3, 2011 (radioworld.com) 2769:by James Careless, March 8, 2010 (radioworld.com). 1231:broadcasting standards that were developed by the 2755:"1560 WFME New York To Suspend Operations Friday" 2739:"Radio fans' holiday joy: KQV is back on the air" 2008:"Dec. 21, 1906: A Very Significant Date in Radio" 1747:"A Science Odyssey: Radio Transmission: FM vs AM" 1335:In 2018 the FCC, led by then-Commission Chairman 587:, respectively. Most important, in 1904–1906 the 408:A family listening to an early broadcast using a 330:, noted that "there are rare cases where, as Dr. 2208:Wisconsin Public Radio's Tradition Of Innovation 1722:"VERIFY: Why Does AM Radio Sound Worse Than FM?" 322:that could only transmit the dots-and-dashes of 2180:Charles Herrold, Inventor of Radio Broadcasting 2080:Proceedings of the Institute of Radio Engineers 1950:Inventing the Wireless Telephone and the Future 1910:"Experiments and Results in Wireless Telephony" 756: 694:in Paris. His company equipped the U.S. Navy's 276: 3116:"Special Report: AM Advocates Watch and Worry" 1982: 1980: 1199:AM stereo § Adoption in the United States 690:. He also broadcast phonograph music from the 3870: 3286: 2700:A Concise History of British Radio, 1922-2002 2670:A Concise History of British Radio, 1922-2002 1124:began playing less expensive recorded music. 27:Radio broadcasting using amplitude modulation 8: 3091:by FHH Law, June 30, 2009 (commlawblog.com). 2549:"The Radio Amateur: Wireless Telephone Here" 2054:, February 1920, pages 1000–1001, 1080-1083. 1814:"Hertzian Telegraphy at the Physical Society 1306:Broadcast relay station § United States 463:into the transmission line, to modulate the 41: 4885:Global telecommunications regulation bodies 3069: 3067: 2289:"Radio Department: Broadcasting Stations", 1866:"Vest-Pocket Wireless Receiving Instrument" 1567:Beginning in the mid-1930s, starting with " 1128:contests was the social media of the time. 611:, invented in 1924, greatly improved audio 416:, so the family had to listen on earphones. 219:AM and FM modulated signals for radio. AM ( 4921: 3877: 3863: 3855: 3668: 3476: 3319: 3293: 3279: 3271: 3005:Radio+Television Business Report (RBR.com) 2880:"Limbaugh Dead; What Next for Talk Radio?" 2692: 2690: 2517:"The News Radiophone To Give Vote Results" 2400:"Hear Caruso Sing by Wireless Thursday!", 2274:"Miscellaneous: Amendments to Regulations" 2182:by Gordon Greb and Mike Adams, 2003, p. 6. 2064:McNicol, Donald Monroe (August 11, 1946). 40: 2922:"RIO is stage for AM spectrum conference" 2892:"Smart AM Receivers for the 21st Century" 2722: 2720: 2303:"Will Give Concert by Wireless Telephone" 2026:, Vol. XXVII (1908), Part I, pp. 606–608. 1870:Electrical Review and Western Electrician 1852:, January 1913, page 52. (Reprinted from 987:. In 1934, a third national network, the 3184:, December 2010. (theradiohistorian.com) 3111: 3109: 2954:"Life on Expanded Band Is (Pretty) Good" 2894:by Stephen F. Smith and Thomas F. King, 2651:"Radio Fans to Pay Tribute to John Bull" 2443:"Foot Ball Score—Via Wireless Telephone" 1691:Lists of radio stations in North America 1603:is a more open effort often used on the 1428:standards adopted in the United States. 1309: 998: 953:American Telephone and Telegraph Company 326:. In October 1898 a London publication, 260:For broader coverage of this topic, see 214: 2863:"Statement of Major Edwin H. Armstrong" 2767:"Whatever Happened to Shortwave Radio?" 2391:, January 1917, page 650. (archive.org) 2196:Cahiers d'Histoire de la Radiodiffusion 2122:"Fessenden, World's First Broadcaster?" 1713: 889:began daily transmissions over station 3101:"Uses of FM Translators Morph Quickly" 2345:, 30 March 1934, p. 446) (nlb.gov.sg). 2220:"A Newspaper's Use of the Radio Phone" 2096:by Helen Fessenden, 1940, pp. 153–154. 2020:"Wireless Telephony: G. Possibilities" 1658:Amplitude Modulation Signalling System 1111:In the 1940s two new broadcast media, 863:Experimental Canadian Marconi station 34:. For the American musical group, see 3084: 3082: 2912:(PDF) (Rio de Janeiro, 1988, ITU.int) 2335:"20th Anniversary of First Broadcast" 2112:, December 23, 2008 (radioworld.com). 1998:: February 2, 1907, pp. 68–70, 79–80. 1261:International Telecommunication Union 1255:AM expanded band § United States 7: 4931: 2474:"Ninth California Theatre Concert", 2198:, Number 118, October–December 2013. 2128:, October 25, 2006 (radioworld.com). 1237:National Association of Broadcasters 3207:"Sammlung alter Biennophone-Radios" 2837:Gitlin, Jonathan M. (23 May 2023). 2565:"To Give Election Results by Radio" 2459:"Wireless Concert Given for Ottawa" 1848:(letter from Captain J. L. Jayne), 1364:(EVs) due to interference from the 1345:Federal Emergency Management Agency 1176:Fairness Doctrine § Revocation 820:Hughes-Wilson presidential election 2978:Morgan, TaNoah (11 October 2002). 2140:by Lee de Forest, 1950, pages 225. 1928:by Hugh G. J. Aitken, 1985, p. 61. 25: 2999:Gutmann, Peter (23 August 2007). 2427:"Communications Commentary: PCGG" 1233:Electronic Industries Association 4930: 4920: 4911: 4910: 4899: 4520:Free-space optical communication 3827: 2968:(FCC DA 97-537), March 17, 1997. 2779:Levenson, Michael (2022-12-10). 2431:Electronics & Wireless World 2325:, 29 March 1914, Part one, p. 2. 1846:"The First Wireless Time Signal" 1820:, January 28, 1898, pp. 452–453. 1804:, October 14, 1898, pp. 814–815. 1414:National Radio Systems Committee 1180:In 1987, the elimination of the 1014:British Broadcasting Corporation 3089:"FCC OK's AM on FM Translators" 2980:"Digital radio approved by FCC" 2869:(1948 hearings), pages 144-145. 2413:"Stop Wireless Concerts Here", 2356:"Wireless Transmission of News" 2264:by Red Barber, 1970, pp. 11–12. 2238:by Asa Briggs, 1961, pp. 49–50. 2093:Fessenden: Builder of Tomorrows 2082:, December 1932, pp. 1849–1862. 1994:: January 26, 1907, pp. 49–51; 3767:Error detection and correction 2449:, December 1919, pp. 295, 321. 2106:"Fessenden — The Next Chapter" 1988:The American Telephone Journal 1916:, January 26, 1907, pp. 49–51. 1914:The American Telephone Journal 293:Early broadcasting development 273:FM broadcasting § History 1: 3144:Muller, Joann (17 May 2023). 2598:WPR's Tradition Of Innovation 2503:(letter from Lee de Forest), 2339:The (Singapore) Straits Times 2319:"Hear Tenor Through Wireless" 639:Early experimental broadcasts 4906:Telecommunication portal 4687:Telecommunications equipment 3196:by Louis M. Bloch, Jr, 1980. 3001:"HD Radio rules take effect" 2898:, April 12, 2015, pages 1-2. 2812:Gilboy, James (2022-07-06). 2614:, September 13, 1926, p. 10. 2612:Reading (Pennsylvania) Eagle 2476:Pacific Coast Musical Review 2151:The American Swedish Monthly 1398:radio frequency interference 1193:AM stereo and AMAX standards 1083:, who became famous for his 1010:British Broadcasting Company 965:Radio Corporation of America 75:; 123 years ago 4423:Alexander Stepanovich Popov 3840:Comparison of radio systems 2523:, August 31, 1920, pp. 1–2. 2389:The Electrical Experimenter 2153:, January 1955, pp. 10, 26. 2066:"Radio's conquest of space" 4978: 4127:Telecommunications history 3813:International broadcasting 3782:FM extended band in Brazil 3246:. MIT Press. p. 199. 2944:, April 28, 1990, page 10. 2928:, May 23, 1988, pp. 55–56. 2571:, October 28, 1920, p. 10. 2169:, November 25, 1908, p. 1. 2022:by Reginald A. Fessenden, 1676:Extended AM broadcast band 1614: 1560: 1557:Other distribution methods 1532:Single-sideband modulation 1504:Extended AM broadcast band 1432:Broadcast band frequencies 1303: 1274: 1252: 1196: 1173: 1035: 923: 623:record in the late 1940s. 484:American Telephone Journal 270: 259: 171:Digital Audio Broadcasting 29: 4894: 4735:Public Switched Telephone 4547:telecommunication circuit 4508:Fiber-optic communication 4253:Francis Blake (telephone) 4048:Optical telecommunication 3821: 3667: 3182:Monitoring Times Magazine 2507:, April 23, 1921, p. 936. 2404:, April 17, 1919, page 1. 2309:, July 21, 1912, page 27. 2280:, January 3, 1922, p. 10. 1872:, April 11, 1914, p. 745. 46: 4646:Orbital angular-momentum 4083:Satellite communications 3922:Communications satellite 2727:"AM Stereo Broadcasting" 2657:, November 1922, p. 222. 2630:. Routledge. p. 6. 2624:Hilmes, Michele (2011). 2553:Pittsburgh Gazette Times 2291:Winnipeg Evening Tribune 1948:"Fessenden, Reginald A. 1856:, October 1912, p. 411). 1850:Electrician and Mechanic 1818:The Electrician (London) 1802:The Electrician (London) 1670:Effective radiated power 1489:Medium-wave broadcasting 1170:Fairness Doctrine repeal 609:dynamic cone loudspeaker 537:Vacuum tube transmitters 497:Alexanderson alternators 477:Ernst F. W. Alexanderson 187:music streaming services 4525:Molecular communication 4348:Gardiner Greene Hubbard 4177:Undersea telegraph line 3912:Cable protection system 3792:Shortwave relay station 3691:Audio signal processing 2743:Pittsburgh Post-Gazette 2555:, Sixth section, p. 13. 2501:News by Radiotelephone" 2489:San Francisco Chronicle 2478:, May 29, 1920, page 9. 2433:, February 1986, p. 26. 2323:Washington Evening Star 2307:San Jose Mercury Herald 2293:, April 25, 1922, p. 5. 2226:, November 1920, p. 10. 2052:Electrical Experimenter 1888:, October 1919, p. 200. 1771:Nahin, Paul J. (2001). 1543:were informally called 266:History of broadcasting 163:television broadcasting 4667:Communication protocol 4453:Charles Sumner Tainter 4268:Walter Houser Brattain 4213:Edwin Howard Armstrong 4021:Information revolution 3686:Audio data compression 2703:. Kelly Publications. 2673:. Kelly Publications. 2569:Cleveland Plain Dealer 2491:, June 20, 1920, p. 8. 2415:Cleveland Plain Dealer 2402:Cleveland Plain Dealer 2337:by Raymond Braillard, 2278:Radio Service Bulletin 2050:by H. Winfield Secor, 2048:"The Versatile Audion" 1836:, March 8, 1902, p. 6. 1647:Digital Radio Mondiale 1617:Low-power broadcasting 1601:Digital Radio Mondiale 1510:Shortwave broadcasting 1358:Emergency Alert System 1315: 1300:FM translator stations 1285: 1246: 1212: 1048: 1004: 935: 785: 777: 770: 753:Organized broadcasting 684:Just Awearyin' for You 563: 471:Fessenden worked with 447:Alternator transmitter 417: 401: 393: 320:spark-gap transmitters 314: 302: 290: 252: 4957:Broadcast engineering 4641:Polarization-division 4373:Narinder Singh Kapany 4338:Erna Schneider Hoover 4258:Jagadish Chandra Bose 4238:Alexander Graham Bell 3969:online video platform 3787:Multipath propagation 3610:MPEG-1 Audio Layer II 3480:Frequency allocations 3355:Frequency allocations 3194:The Gas Pipe Networks 2697:Street, Sean (2002). 2667:Street, Sean (2002). 2587:, August 1922, p. 40. 2537:Broadcasting Magazine 2465:, May 21, 1920, p. 4. 2417:, May 29, 1919, p. 9. 1974:Aitken (1985), p. 69. 1937:Aitken (1985), p. 62. 1798:"Wireless Telegraphy" 1696:Oldest radio stations 1457:Longwave broadcasting 1372:Technical information 1331:Additional activities 1313: 1284: 1241: 1210: 1107:Decline in popularity 1045: 1032:"Golden Age of Radio" 1002: 933: 783: 775: 569:electrolytic detector 561: 527:Charles "Doc" Herrold 407: 399: 388: 308: 300: 218: 198:digital transmissions 4962:Radio communications 4483:Vladimir K. Zworykin 4443:Almon Brown Strowger 4413:Charles Grafton Page 4068:Prepaid mobile phone 3996:Electrical telegraph 3740:Technical (emission) 3134:, November 20, 2018. 3044:The Federal Register 3024:The Federal Register 2745:, December 24, 2019. 2124:by James E. O'Neal, 2108:by James E. O'Neal, 1854:The American Jeweler 1653:Amplitude modulation 1259:On June 8, 1988, an 989:Mutual Radio Network 585:John Ambrose Fleming 342:On January 1, 1902, 225:Frequency Modulation 221:Amplitude Modulation 167:frequency modulation 136:amplitude modulation 48:amplitude modulation 4433:Johann Philipp Reis 4192:Wireless revolution 4154:The Telephone Cases 4011:Hydraulic telegraph 3180:by John Schneider, 3027:. 25 November 2019. 2533:WWJ (advertisement) 1926:The Continuous Wave 1898:U.S. Patent 706,737 1538:VHF AM broadcasting 1056:, mystery serials, 1038:Golden Age of Radio 961:commercial messages 649:Christmas Eve 1906. 607:could be used. The 579:) were invented by 375:telephone newspaper 344:Nathan Stubblefield 159:Golden Age of Radio 43: 4631:Frequency-division 4608:Telephone exchange 4478:Charles Wheatstone 4408:Jun-ichi Nishizawa 4383:Innocenzo Manzetti 4318:Reginald Fessenden 4053:Optical telegraphy 3886:Telecommunications 3047:. 3 December 2020. 2785:The New York Times 2741:by Maria Sciullo, 2447:Radio Amateur News 1886:Radio Amateur News 1728:. November 6, 2017 1470:(LF)) (148.5 1316: 1286: 1213: 1164:Edwin H. Armstrong 1081:Franklin Roosevelt 1070:situation comedies 1049: 1005: 936: 786: 778: 613:frequency response 581:Reginald Fessenden 564: 422:Reginald Fessenden 418: 402: 394: 315: 303: 253: 235:, is mixed with a 196:Compared to FM or 179:HD (digital) radio 132:radio broadcasting 92:Reginald Fessenden 4944: 4943: 4682:Store and forward 4677:Data transmission 4591:Network switching 4542:Transmission line 4388:Guglielmo Marconi 4353:Internet pioneers 4218:Mohamed M. Atalla 4187:Whistled language 3852: 3851: 3848: 3847: 3772:FM broadcast band 3679:Technical (audio) 3576: 3575: 3468: 3467: 2940:by Bill Holland, 2610:(advertisement), 2445:by Morris Press, 1912:, by John Grant, 1884:(advertisement), 1882:"Radio Apparatus" 1623:microbroadcasters 1611:Microbroadcasting 1578:Telefonrundspruch 1569:The Brown Network 1476:ITU Region 1 1442:Radio Regulations 1362:electric vehicles 1351:Electric vehicles 1182:Fairness Doctrine 951:In the U.S., the 897:November 2, 1920. 883:On this date the 839:November 6, 1919. 825:New York American 725:January 15, 1920. 696:Great White Fleet 461:carbon microphone 125: 124: 16:(Redirected from 4969: 4934: 4933: 4924: 4923: 4914: 4913: 4904: 4903: 4902: 4775:Notable networks 4765:Wireless network 4705:Cellular network 4697:Types of network 4672:Computer network 4559:Network topology 4473:Thomas A. Watson 4328:Oliver Heaviside 4313:Philo Farnsworth 4288:Daniel Davis Jr. 4263:Charles Bourseul 4223:John Logie Baird 3932:Data compression 3927:Computer network 3879: 3872: 3865: 3856: 3834:Radio portal 3832: 3831: 3830: 3808:History of radio 3752:AM expanded band 3669: 3552:Commercial radio 3477: 3320: 3295: 3288: 3281: 3272: 3265: 3264: 3262: 3260: 3237: 3231: 3225: 3219: 3218: 3216: 3214: 3209:. Biennophone.ch 3203: 3197: 3191: 3185: 3175: 3169: 3168: 3164: 3158: 3157: 3155: 3153: 3141: 3135: 3132:Federal Register 3125: 3119: 3113: 3104: 3098: 3092: 3086: 3077: 3071: 3062: 3055: 3049: 3048: 3035: 3029: 3028: 3015: 3009: 3008: 2996: 2990: 2989: 2975: 2969: 2963: 2957: 2951: 2945: 2935: 2929: 2919: 2913: 2905: 2899: 2889: 2883: 2876: 2870: 2860: 2854: 2853: 2851: 2849: 2834: 2828: 2827: 2825: 2824: 2809: 2803: 2802: 2800: 2799: 2776: 2770: 2764: 2758: 2752: 2746: 2736: 2730: 2724: 2715: 2714: 2694: 2685: 2684: 2664: 2658: 2648: 2642: 2641: 2621: 2615: 2605: 2599: 2594: 2588: 2585:The Wireless Age 2578: 2572: 2562: 2556: 2551:by C. E. Urban, 2546: 2540: 2530: 2524: 2514: 2508: 2505:Electrical World 2498: 2492: 2485: 2479: 2472: 2466: 2463:Montreal Gazette 2456: 2450: 2440: 2434: 2424: 2418: 2411: 2405: 2398: 2392: 2382: 2376: 2375: 2373: 2371: 2352: 2346: 2332: 2326: 2316: 2310: 2300: 2294: 2287: 2281: 2271: 2265: 2262:The Broadcasters 2259: 2253: 2252: 2245: 2239: 2233: 2227: 2224:The Wireless Age 2217: 2211: 2205: 2199: 2189: 2183: 2176: 2170: 2160: 2154: 2147: 2141: 2135: 2129: 2119: 2113: 2103: 2097: 2089: 2083: 2076: 2070: 2069: 2061: 2055: 2045: 2039: 2033: 2027: 2017: 2011: 2005: 1999: 1984: 1975: 1972: 1966: 1965: 1963: 1962: 1944: 1938: 1935: 1929: 1923: 1917: 1907: 1901: 1895: 1889: 1879: 1873: 1863: 1857: 1843: 1837: 1827: 1821: 1811: 1805: 1795: 1789: 1788: 1768: 1762: 1761: 1759: 1757: 1743: 1737: 1736: 1734: 1733: 1718: 1681:History of radio 1500:Medium frequency 1152:electric vehicle 1089:Great Depression 1074:children's shows 1018:receiver license 969:General Electric 912:January 3, 1921. 881:August 20, 1920. 768: 767:, sportscaster, 745:August 27, 1920. 680:I Love You Truly 628:transistor radio 589:crystal detector 573:thermionic diode 523:Quirino Majorana 514:Valdemar Poulsen 504:Arc transmitters 473:General Electric 441:arc-transmitters 288: 287:, sportscaster, 262:History of radio 121: 118: 116: 114: 112: 83: 81: 76: 44: 21: 4977: 4976: 4972: 4971: 4970: 4968: 4967: 4966: 4947: 4946: 4945: 4940: 4900: 4898: 4890: 4832: 4769: 4691: 4655: 4612: 4561: 4553: 4494: 4487: 4393:Robert Metcalfe 4248:Tim Berners-Lee 4196: 4016:Information Age 3888: 3883: 3853: 3844: 3828: 3826: 3817: 3796: 3777:FM broadcasting 3747:AM broadcasting 3735: 3695: 3674: 3663: 3619: 3572: 3546: 3515:Digital systems 3510: 3495: 3464: 3425:Digital systems 3420: 3349: 3311: 3299: 3269: 3268: 3258: 3256: 3254: 3239: 3238: 3234: 3228:"Digital Radio" 3226: 3222: 3212: 3210: 3205: 3204: 3200: 3192: 3188: 3176: 3172: 3166: 3165: 3161: 3151: 3149: 3143: 3142: 3138: 3126: 3122: 3114: 3107: 3099: 3095: 3087: 3080: 3072: 3065: 3056: 3052: 3037: 3036: 3032: 3017: 3016: 3012: 2998: 2997: 2993: 2977: 2976: 2972: 2964: 2960: 2952: 2948: 2936: 2932: 2920: 2916: 2906: 2902: 2890: 2886: 2877: 2873: 2861: 2857: 2847: 2845: 2836: 2835: 2831: 2822: 2820: 2811: 2810: 2806: 2797: 2795: 2778: 2777: 2773: 2765: 2761: 2753: 2749: 2737: 2733: 2725: 2718: 2711: 2696: 2695: 2688: 2681: 2666: 2665: 2661: 2649: 2645: 2638: 2623: 2622: 2618: 2606: 2602: 2595: 2591: 2579: 2575: 2563: 2559: 2547: 2543: 2531: 2527: 2515: 2511: 2499: 2495: 2486: 2482: 2473: 2469: 2457: 2453: 2441: 2437: 2425: 2421: 2412: 2408: 2399: 2395: 2383: 2379: 2369: 2367: 2354: 2353: 2349: 2333: 2329: 2317: 2313: 2301: 2297: 2288: 2284: 2272: 2268: 2260: 2256: 2247: 2246: 2242: 2234: 2230: 2218: 2214: 2206: 2202: 2190: 2186: 2177: 2173: 2161: 2157: 2148: 2144: 2138:Father of Radio 2136: 2132: 2120: 2116: 2104: 2100: 2090: 2086: 2077: 2073: 2063: 2062: 2058: 2046: 2042: 2034: 2030: 2018: 2014: 2006: 2002: 1985: 1978: 1973: 1969: 1960: 1958: 1946: 1945: 1941: 1936: 1932: 1924: 1920: 1908: 1904: 1896: 1892: 1880: 1876: 1864: 1860: 1844: 1840: 1834:The Sunny South 1828: 1824: 1812: 1808: 1796: 1792: 1785: 1770: 1769: 1765: 1755: 1753: 1745: 1744: 1740: 1731: 1729: 1720: 1719: 1715: 1710: 1643: 1619: 1613: 1605:shortwave bands 1595:'s proprietary 1573:carrier current 1565: 1563:Carrier current 1559: 1540: 1519:(also known as 1512: 1498:(also known as 1491: 1466:(also known as 1459: 1434: 1374: 1366:electric motors 1353: 1333: 1308: 1302: 1279: 1273: 1257: 1251: 1205: 1197:Main articles: 1195: 1178: 1172: 1160: 1109: 1040: 1034: 997: 949: 928: 922: 848:slope detection 832:April 17, 1919. 801:March 28, 1914. 769: 763: 755: 641: 556: 539: 506: 449: 430:continuous wave 370: 337:The Electrician 328:The Electrician 295: 289: 283: 275: 269: 258: 227:) are types of 175:satellite radio 148:shortwave radio 128:AM broadcasting 109: 79: 77: 74: 42:AM broadcasting 39: 36:AM Radio (band) 32:AM Radio (song) 28: 23: 22: 15: 12: 11: 5: 4975: 4973: 4965: 4964: 4959: 4949: 4948: 4942: 4941: 4939: 4938: 4928: 4918: 4908: 4895: 4892: 4891: 4889: 4888: 4881: 4876: 4871: 4866: 4861: 4860: 4859: 4854: 4846: 4840: 4838: 4834: 4833: 4831: 4830: 4825: 4820: 4815: 4810: 4805: 4800: 4795: 4790: 4785: 4779: 4777: 4771: 4770: 4768: 4767: 4762: 4757: 4752: 4747: 4742: 4737: 4732: 4727: 4722: 4717: 4712: 4707: 4701: 4699: 4693: 4692: 4690: 4689: 4684: 4679: 4674: 4669: 4663: 4661: 4657: 4656: 4654: 4653: 4648: 4643: 4638: 4633: 4628: 4626:Space-division 4622: 4620: 4614: 4613: 4611: 4610: 4605: 4604: 4603: 4598: 4588: 4587: 4586: 4576: 4571: 4565: 4563: 4555: 4554: 4552: 4551: 4550: 4549: 4539: 4538: 4537: 4527: 4522: 4517: 4516: 4515: 4505: 4499: 4497: 4489: 4488: 4486: 4485: 4480: 4475: 4470: 4465: 4463:Camille Tissot 4460: 4455: 4450: 4445: 4440: 4438:Claude Shannon 4435: 4430: 4428:Tivadar Puskás 4425: 4420: 4415: 4410: 4405: 4400: 4398:Antonio Meucci 4395: 4390: 4385: 4380: 4375: 4370: 4368:Charles K. Kao 4365: 4360: 4355: 4350: 4345: 4343:Harold Hopkins 4340: 4335: 4330: 4325: 4320: 4315: 4310: 4305: 4300: 4295: 4290: 4285: 4280: 4275: 4270: 4265: 4260: 4255: 4250: 4245: 4243:Emile Berliner 4240: 4235: 4230: 4225: 4220: 4215: 4210: 4204: 4202: 4198: 4197: 4195: 4194: 4189: 4184: 4182:Videotelephony 4179: 4174: 4173: 4172: 4167: 4157: 4150: 4145: 4139: 4134: 4129: 4124: 4119: 4118: 4117: 4112: 4107: 4097: 4096: 4095: 4085: 4080: 4078:Radiotelephone 4075: 4070: 4065: 4060: 4055: 4050: 4045: 4044: 4043: 4033: 4028: 4023: 4018: 4013: 4008: 4003: 3998: 3993: 3988: 3983: 3982: 3981: 3976: 3971: 3966: 3964:Internet video 3956: 3955: 3954: 3949: 3944: 3939: 3929: 3924: 3919: 3914: 3909: 3904: 3898: 3896: 3890: 3889: 3884: 3882: 3881: 3874: 3867: 3859: 3850: 3849: 3846: 3845: 3843: 3842: 3837: 3822: 3819: 3818: 3816: 3815: 3810: 3804: 3802: 3798: 3797: 3795: 3794: 3789: 3784: 3779: 3774: 3769: 3764: 3759: 3754: 3749: 3743: 3741: 3737: 3736: 3734: 3733: 3728: 3726:Kahn-Hazeltine 3723: 3718: 3713: 3707: 3705: 3697: 3696: 3694: 3693: 3688: 3682: 3680: 3676: 3675: 3673:Related topics 3672: 3665: 3664: 3662: 3661: 3656: 3651: 3646: 3641: 3636: 3630: 3628: 3621: 3620: 3618: 3617: 3612: 3607: 3602: 3597: 3592: 3586: 3584: 3578: 3577: 3574: 3573: 3571: 3570: 3569: 3568: 3557: 3555: 3548: 3547: 3545: 3544: 3539: 3534: 3529: 3524: 3518: 3516: 3512: 3511: 3509: 3508: 3503: 3498: 3493: 3489: 3483: 3481: 3474: 3470: 3469: 3466: 3465: 3463: 3462: 3457: 3454: 3449: 3444: 3439: 3434: 3428: 3426: 3422: 3421: 3419: 3418: 3408: 3390: 3380: 3370: 3359: 3357: 3351: 3350: 3348: 3347: 3342: 3337: 3331: 3329: 3317: 3313: 3312: 3300: 3298: 3297: 3290: 3283: 3275: 3267: 3266: 3252: 3232: 3220: 3198: 3186: 3170: 3159: 3136: 3120: 3105: 3093: 3078: 3063: 3050: 3030: 3010: 2991: 2970: 2958: 2946: 2930: 2914: 2900: 2884: 2878:Scott Fybush. 2871: 2855: 2829: 2804: 2771: 2759: 2747: 2731: 2716: 2709: 2686: 2679: 2659: 2643: 2637:978-0415883856 2636: 2616: 2600: 2589: 2573: 2557: 2541: 2525: 2509: 2493: 2480: 2467: 2451: 2435: 2419: 2406: 2393: 2377: 2347: 2327: 2311: 2295: 2282: 2266: 2254: 2240: 2228: 2212: 2200: 2184: 2171: 2155: 2142: 2130: 2114: 2098: 2084: 2071: 2056: 2040: 2028: 2012: 2000: 1976: 1967: 1939: 1930: 1918: 1902: 1890: 1874: 1858: 1838: 1822: 1806: 1790: 1783: 1763: 1738: 1712: 1711: 1709: 1706: 1705: 1704: 1698: 1693: 1688: 1683: 1678: 1673: 1667: 1661: 1655: 1650: 1642: 1639: 1612: 1609: 1561:Main article: 1558: 1555: 1539: 1536: 1525:audio fidelity 1521:High frequency 1511: 1508: 1490: 1487: 1458: 1455: 1433: 1430: 1407:capture effect 1402:FM frequencies 1373: 1370: 1352: 1349: 1332: 1329: 1304:Main article: 1301: 1298: 1275:Main article: 1272: 1269: 1253:Main article: 1250: 1247: 1235:(EIA) and the 1194: 1191: 1171: 1168: 1159: 1156: 1108: 1105: 1085:fireside chats 1036:Main article: 1033: 1030: 996: 995:United Kingdom 993: 948: 945: 924:Main article: 921: 920:Radio networks 918: 917: 916: 909: 894: 878: 868: 858: 851: 836: 829: 812:November 1916. 809: 805:Laeken station 798: 794:July 21, 1912. 761: 754: 751: 750: 749: 742: 722: 716: 713:Laeken station 706: 699: 676:Eugenia Farrar 664: 661:New Year's Eve 640: 637: 597:crystal radios 555: 552: 538: 535: 505: 502: 448: 445: 379:radiotelephone 369: 366: 294: 291: 281: 257: 254: 206:all-news radio 183:Internet radio 123: 122: 107: 103: 102: 99: 95: 94: 89: 85: 84: 71: 67: 66: 63: 59: 58: 55: 51: 50: 26: 24: 14: 13: 10: 9: 6: 4: 3: 2: 4974: 4963: 4960: 4958: 4955: 4954: 4952: 4937: 4929: 4927: 4919: 4917: 4909: 4907: 4897: 4896: 4893: 4886: 4882: 4880: 4877: 4875: 4872: 4870: 4867: 4865: 4862: 4858: 4855: 4853: 4850: 4849: 4847: 4845: 4842: 4841: 4839: 4835: 4829: 4826: 4824: 4821: 4819: 4816: 4814: 4811: 4809: 4806: 4804: 4801: 4799: 4796: 4794: 4791: 4789: 4786: 4784: 4781: 4780: 4778: 4776: 4772: 4766: 4763: 4761: 4758: 4756: 4753: 4751: 4748: 4746: 4743: 4741: 4738: 4736: 4733: 4731: 4728: 4726: 4723: 4721: 4718: 4716: 4713: 4711: 4708: 4706: 4703: 4702: 4700: 4698: 4694: 4688: 4685: 4683: 4680: 4678: 4675: 4673: 4670: 4668: 4665: 4664: 4662: 4658: 4652: 4651:Code-division 4649: 4647: 4644: 4642: 4639: 4637: 4636:Time-division 4634: 4632: 4629: 4627: 4624: 4623: 4621: 4619: 4615: 4609: 4606: 4602: 4599: 4597: 4594: 4593: 4592: 4589: 4585: 4582: 4581: 4580: 4577: 4575: 4572: 4570: 4567: 4566: 4564: 4562:and switching 4560: 4556: 4548: 4545: 4544: 4543: 4540: 4536: 4533: 4532: 4531: 4528: 4526: 4523: 4521: 4518: 4514: 4513:optical fiber 4511: 4510: 4509: 4506: 4504: 4503:Coaxial cable 4501: 4500: 4498: 4496: 4490: 4484: 4481: 4479: 4476: 4474: 4471: 4469: 4466: 4464: 4461: 4459: 4456: 4454: 4451: 4449: 4446: 4444: 4441: 4439: 4436: 4434: 4431: 4429: 4426: 4424: 4421: 4419: 4418:Radia Perlman 4416: 4414: 4411: 4409: 4406: 4404: 4401: 4399: 4396: 4394: 4391: 4389: 4386: 4384: 4381: 4379: 4376: 4374: 4371: 4369: 4366: 4364: 4361: 4359: 4356: 4354: 4351: 4349: 4346: 4344: 4341: 4339: 4336: 4334: 4331: 4329: 4326: 4324: 4321: 4319: 4316: 4314: 4311: 4309: 4308:Lee de Forest 4306: 4304: 4303:Thomas Edison 4301: 4299: 4296: 4294: 4293:Donald Davies 4291: 4289: 4286: 4284: 4281: 4279: 4278:Claude Chappe 4276: 4274: 4271: 4269: 4266: 4264: 4261: 4259: 4256: 4254: 4251: 4249: 4246: 4244: 4241: 4239: 4236: 4234: 4231: 4229: 4226: 4224: 4221: 4219: 4216: 4214: 4211: 4209: 4206: 4205: 4203: 4199: 4193: 4190: 4188: 4185: 4183: 4180: 4178: 4175: 4171: 4168: 4166: 4163: 4162: 4161: 4158: 4156: 4155: 4151: 4149: 4146: 4143: 4140: 4138: 4135: 4133: 4130: 4128: 4125: 4123: 4122:Smoke signals 4120: 4116: 4113: 4111: 4108: 4106: 4103: 4102: 4101: 4100:Semiconductor 4098: 4094: 4091: 4090: 4089: 4086: 4084: 4081: 4079: 4076: 4074: 4071: 4069: 4066: 4064: 4061: 4059: 4056: 4054: 4051: 4049: 4046: 4042: 4039: 4038: 4037: 4034: 4032: 4029: 4027: 4024: 4022: 4019: 4017: 4014: 4012: 4009: 4007: 4004: 4002: 3999: 3997: 3994: 3992: 3989: 3987: 3984: 3980: 3977: 3975: 3972: 3970: 3967: 3965: 3962: 3961: 3960: 3959:Digital media 3957: 3953: 3950: 3948: 3945: 3943: 3940: 3938: 3935: 3934: 3933: 3930: 3928: 3925: 3923: 3920: 3918: 3915: 3913: 3910: 3908: 3905: 3903: 3900: 3899: 3897: 3895: 3891: 3887: 3880: 3875: 3873: 3868: 3866: 3861: 3860: 3857: 3841: 3838: 3836: 3835: 3824: 3823: 3820: 3814: 3811: 3809: 3806: 3805: 3803: 3799: 3793: 3790: 3788: 3785: 3783: 3780: 3778: 3775: 3773: 3770: 3768: 3765: 3763: 3762:Digital radio 3760: 3758: 3755: 3753: 3750: 3748: 3745: 3744: 3742: 3738: 3732: 3729: 3727: 3724: 3722: 3719: 3717: 3714: 3712: 3709: 3708: 3706: 3703: 3698: 3692: 3689: 3687: 3684: 3683: 3681: 3677: 3670: 3666: 3660: 3657: 3655: 3652: 3650: 3647: 3645: 3642: 3640: 3637: 3635: 3632: 3631: 3629: 3626: 3622: 3616: 3613: 3611: 3608: 3606: 3603: 3601: 3598: 3596: 3593: 3591: 3588: 3587: 3585: 3583: 3579: 3567: 3564: 3563: 3562: 3559: 3558: 3556: 3553: 3549: 3543: 3540: 3538: 3535: 3533: 3530: 3528: 3525: 3523: 3520: 3519: 3517: 3513: 3507: 3504: 3502: 3499: 3497: 3490: 3488: 3485: 3484: 3482: 3478: 3475: 3471: 3461: 3458: 3455: 3453: 3450: 3448: 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W. Pickard 590: 586: 582: 578: 577:Fleming valve 574: 570: 560: 553: 551: 549: 544: 536: 534: 532: 531:Lee de Forest 528: 524: 520: 515: 511: 510:arc converter 503: 501: 498: 493: 488: 485: 480: 478: 474: 469: 466: 462: 458: 454: 446: 444: 442: 438: 433: 431: 427: 423: 415: 411: 410:crystal radio 406: 398: 391: 387: 383: 380: 376: 367: 365: 364:enthusiasts. 363: 362:amateur radio 358: 352: 349: 345: 340: 338: 333: 329: 325: 321: 312: 307: 299: 292: 286: 280: 274: 267: 263: 255: 250: 246: 242: 238: 234: 230: 226: 222: 217: 213: 211: 207: 203: 199: 194: 192: 188: 184: 180: 176: 172: 168: 164: 160: 156: 151: 149: 145: 141: 137: 133: 129: 120: 108: 104: 100: 96: 93: 90: 86: 72: 68: 64: 60: 56: 52: 49: 45: 37: 33: 19: 4618:Multiplexing 4493:Transmission 4458:Nikola Tesla 4448:Henry Sutton 4403:Samuel Morse 4333:Robert Hooke 4298:Amos Dolbear 4233:John Bardeen 4152: 4132:Telautograph 4036:Mobile phone 3991:Edholm's law 3974:social media 3907:Broadcasting 3825: 3746: 3309:broadcasting 3257:. 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Retrieved 1725: 1716: 1631:pirate radio 1620: 1590: 1577: 1566: 1551: 1544: 1541: 1529: 1514: 1513: 1493: 1492: 1480: 1461: 1460: 1453: 1446: 1435: 1411: 1375: 1354: 1334: 1325: 1321: 1317: 1294: 1287: 1265: 1258: 1242: 1222: 1218: 1214: 1179: 1161: 1149: 1145: 1141: 1130: 1126: 1110: 1103:ideologies. 1078: 1050: 1006: 973:Westinghouse 950: 937: 911: 901:Frank Conrad 896: 886:Detroit News 884: 880: 870: 860: 853: 838: 831: 823: 811: 800: 793: 787: 757: 744: 739:Nellie Melba 732: 724: 718: 708: 701: 692:Eiffel Tower 672:telharmonium 666: 648: 642: 625: 621:long-playing 605:loudspeakers 565: 541:Advances in 540: 519:Ernst Ruhmer 507: 489: 483: 481: 470: 465:carrier wave 450: 434: 426:damped waves 419: 414:loudspeakers 390:Nellie Melba 371: 357:Eiffel Tower 353: 341: 336: 327: 316: 277: 237:carrier wave 210:sports radio 195: 152: 127: 126: 70:Year started 54:Abbreviation 4818:NPL network 4530:Radio waves 4468:Alfred Vail 4378:Hedy Lamarr 4363:Dawon Kahng 4323:Elisha Gray 4283:Yogen Dalal 4208:Nasir Ahmed 4142:Teleprinter 4006:Heliographs 3757:Cable radio 3700:Technical ( 3460:DVB-T2 Lite 3316:Terrestrial 2343:World-Radio 2126:Radio World 2110:Radio World 1629:rules, and 1586:Rediffusion 1495:Medium wave 1394:radio noise 1386:loudspeaker 1378:radio waves 1087:during the 1058:soap operas 1054:radio plays 857:permission. 595:. Homemade 548:transistors 543:vacuum tube 155:vacuum tube 140:medium wave 4951:Categories 4864:Antarctica 4823:Toasternet 4745:Television 4228:Paul Baran 4160:Television 4144:(teletype) 4137:Telegraphy 4115:transistor 4093:Phryctoria 4063:Photophone 4041:Smartphone 4031:Mass media 3639:DirectBand 3625:Subcarrier 3327:modulation 3259:7 February 2823:2022-12-29 2798:2022-12-29 1961:2017-07-22 1784:0387951504 1732:2022-12-29 1708:References 1615:See also: 1174:See also: 1117:television 1093:propaganda 1062:quiz shows 1028:networks. 871:June 1920. 854:Late 1919. 765:Red Barber 734:Daily Mail 729:Chelmsford 719:1914–1919. 702:June 1910. 667:1907-1912. 632:transistor 492:microphone 453:alternator 437:alternator 324:Morse code 285:Red Barber 271:See also: 229:modulation 223:) and FM ( 202:talk radio 191:podcasting 4848:Americas 4837:Locations 4808:Internet2 4569:Bandwidth 4273:Vint Cerf 4170:streaming 4148:Telephone 4088:Semaphore 3979:streaming 3702:AM stereo 3561:Sirius XM 3554:providers 3473:Satellite 3230:(fcc.gov) 3057:Logo for 2942:Billboard 2818:The Drive 2793:0362-4331 2729:(fcc.gov) 2360:Telephony 2210:(wpr.org) 1516:Shortwave 1449:sidebands 1422:bandwidth 1418:bandwidth 1137:AM stereo 1101:communist 678:singing " 601:earphones 554:Receivers 348:induction 245:frequency 241:amplitude 169:) radio, 161:", until 119:/am-radio 4916:Category 4803:Internet 4793:CYCLADES 4710:Ethernet 4660:Concepts 4584:terminal 4535:wireless 4358:Bob Kahn 4201:Pioneers 4026:Internet 3917:Cable TV 3801:Cultural 3731:Magnavox 3704:formats) 3654:SCA/SCMO 3649:RDS/RBDS 3452:HD Radio 3442:DRM/DRM+ 3437:DAB/DAB+ 1701:MW DXing 1641:See also 1597:HD Radio 1593:iBiquity 1582:longwave 1483:longwave 1463:Longwave 1390:earphone 1337:Ajit Pai 1290:iBiquity 1277:HD Radio 1271:HD radio 1113:FM radio 1026:Regional 1022:National 941:networks 762:— 475:'s (GE) 282:— 249:extracts 144:longwave 117:/general 18:Am radio 4936:Commons 4926:Outline 4879:Oceania 4798:FidoNet 4783:ARPANET 4596:circuit 4165:digital 3894:History 3627:signals 3595:AMR-WB+ 3447:FMeXtra 3213:23 July 3148:. Axios 1996:Part II 1751:pbs.org 1635:FM band 1627:Part 15 1382:voltage 1097:fascist 967:(RCA), 682:" and " 256:History 173:(DAB), 150:bands. 106:Website 98:License 88:Authors 78: ( 4874:Europe 4844:Africa 4828:Usenet 4788:BITNET 4725:Mobile 4601:packet 4110:MOSFET 4105:device 3902:Beacon 3721:Harris 3716:C-QUAM 3605:HE-AAC 3582:Codecs 3566:Canada 3532:DVB-SH 3506:S band 3501:L band 3487:C band 3411:L band 3302:Analog 3250: 3152:18 May 2848:23 May 2791: 2707: 2677: 2634: 2581:"KDKA" 1992:Part I 1781: 1225:C-QUAM 1201:, and 1133:stereo 1121:format 971:, and 529:, and 233:studio 189:, and 134:using 101:Public 65:Active 62:Status 4857:South 4852:North 4813:JANET 4750:Telex 4740:Radio 4579:Nodes 4574:Links 4495:media 4073:Radio 4058:Pager 3986:Drums 3952:video 3947:image 3937:audio 3711:Belar 3537:S-DMB 3527:DAB-S 3432:CAM-D 3345:COFDM 3324:Radio 1664:CAM-D 1621:Some 835:Navy. 709:1913. 332:Lodge 4869:Asia 4755:UUCP 4715:ISDN 3659:DARC 3634:AMSS 3615:DRA+ 3496:band 3405:high 3304:and 3261:2021 3248:ISBN 3215:2017 3154:2023 3059:WCHL 2850:2023 2789:ISSN 2705:ISBN 2675:ISBN 2632:ISBN 2372:2015 1956:IEEE 1779:ISBN 1758:2022 1546:Apex 1426:AMAX 1229:AMAX 1203:AMAX 1115:and 1099:and 1072:and 1024:and 957:WEAF 906:KDKA 843:PCGG 803:The 583:and 571:and 264:and 208:and 146:and 115:.gov 113:.fcc 80:1901 73:1901 4760:WAN 4730:NGN 4720:LAN 4001:Fax 3942:DCT 3644:PAD 3600:HDC 3590:AAC 3542:SDR 3522:ADR 3456:CDR 3415:UHF 3401:mid 3397:low 3393:VHF 1472:kHz 1440:'s 1438:ITU 1388:or 985:CBS 981:NBC 977:WJZ 891:8MK 875:6XC 865:XWA 816:2XG 482:An 311:2XG 130:is 111:www 4953:: 3403:/ 3399:/ 3387:HF 3383:SW 3377:MF 3373:MW 3367:LF 3363:LW 3340:FM 3335:AM 3130:, 3108:^ 3081:^ 3066:^ 3041:. 3021:. 3003:. 2982:. 2924:, 2841:. 2816:. 2787:. 2783:. 2719:^ 2689:^ 2653:, 2583:, 2567:, 2535:, 2519:, 2461:, 2429:, 2387:, 2364:71 2362:. 2358:. 2321:, 2305:, 2276:, 2222:, 2165:, 1990:. 1979:^ 1954:. 1868:, 1832:, 1816:, 1800:, 1749:. 1724:. 1549:. 1527:. 1396:, 1068:, 1064:, 1060:, 850:.) 619:, 533:. 525:, 521:, 457:Hz 204:, 193:. 185:, 181:, 177:, 57:AM 4887:) 4883:( 3878:e 3871:t 3864:v 3494:u 3492:K 3417:) 3413:( 3407:) 3395:( 3389:) 3385:( 3379:) 3375:( 3369:) 3365:( 3294:e 3287:t 3280:v 3263:. 3217:. 3156:. 3007:. 2988:. 2852:. 2826:. 2801:. 2713:. 2683:. 2640:. 2374:. 2251:. 1964:. 1952:" 1787:. 1760:. 1735:. 1576:( 575:( 268:. 82:) 38:. 20:)

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