AM broadcasting is radio broadcasting using amplitude modulation (AM) transmissions. It was the first method developed for making audio radio transmissions, and is still used worldwide, primarily for medium wave (also known as "AM band") transmissions, but also on the longwave and shortwave radio bands.
112-546: KLZ (560 AM ) is a commercial radio station licensed to Denver, Colorado . It airs a conservative talk radio format and is owned by Crawford Broadcasting , with studios on South Parker Road in Aurora . It is the oldest radio station in the state of Colorado, and one of the oldest in the United States. KLZ is a Class B station powered at 5,000 watts. To avoid interfering with other stations on 560 AM , it uses
224-536: A directional antenna with a two- tower array . The transmitter is on Niver Creek Trail off Steele Street in Welby . The signal covers much of the population center of Colorado, from Fort Collins to Colorado Springs and Pueblo . The station is licensed to broadcast using HD Radio technology. In addition, listeners in Denver can hear KLZ programming on 99-watt FM translator K264BO at 100.7 MHz . KLZ airs
336-472: A "chain". The Radio Corporation of America (RCA), General Electric , and Westinghouse organized a competing network around its own flagship station, RCA's WJZ (now WABC) in New York City, but were hampered by AT&T's refusal to lease connecting lines or allow them to sell airtime. In 1926 AT&T sold its radio operations to RCA, which used them to form the nucleus of the new NBC network. By
448-846: A 10 shilling receiver license fee. Both highbrow and mass-appeal programmes were carried by the National and Regional networks. The period from the early 1920s through the 1940s is often called the "Golden Age of Radio". During this period AM radio was the main source of home entertainment, until it was replaced by television. For the first time entertainment was provided from outside the home, replacing traditional forms of entertainment such as oral storytelling and music from family members. New forms were created, including radio plays , mystery serials, soap operas , quiz shows , variety hours , situation comedies and children's shows . Radio news, including remote reporting, allowed listeners to be vicariously present at notable events. Radio greatly eased
560-539: A ballet, Harriette, ou la servante de Greenwiche , derived from a text by Saint-Georges, for the ballerina Adèle Dumilâtre . This was first performed by the Paris Opera Ballet at the Salle Le Peletier on 21 February 1844. The time available for the composition was short, so the second and third acts were assigned, respectively, to Friedrich Burgmüller and Édouard Deldevez . The opera Martha
672-507: A central station to all parts of the United States", he was unable to overcome the inherent distance limitations of this technology. The earliest public radiotelegraph broadcasts were provided as government services, beginning with daily time signals inaugurated on January 1, 1905, by a number of U.S. Navy stations. In Europe, signals transmitted from a station located on the Eiffel Tower were received throughout much of Europe. In both
784-610: A concerted attempt to specify performance of AM receivers through the 1993 AMAX standard, a joint effort of the EIA and the NAB, with FCC backing... The FCC rapidly followed up on this with codification of the CQUAM AM stereo standard, also in 1993. At this point, the stage appeared to be set for rejuvenation of the AM band. Nevertheless, with the legacy of confusion and disappointment in the rollout of
896-635: A consortium, the British Broadcasting Company (BBC), established on 18 October 1922, which was given a monopoly on broadcasting. This enterprise was supported by a tax on radio sets sales, plus an annual license fee on receivers, collected by the Post Office. Initially the eight stations were allowed regional autonomy. In 1927, the original broadcasting organization was replaced by a government chartered British Broadcasting Corporation . an independent nonprofit supported solely by
1008-564: A continuous-wave (CW) transmitter. Fessenden began his research on audio transmissions while doing developmental work for the United States Weather Service on Cobb Island, Maryland. Because he did not yet have a continuous-wave transmitter, initially he worked with an experimental "high-frequency spark" transmitter, taking advantage of the fact that the higher the spark rate, the closer a spark-gap transmission comes to producing continuous waves. He later reported that, in
1120-444: A couple of wenches to do their housework and, being struck by the beauty and charm of the two masqueraders, proceed to hire them. Lady Harriet gives her name as Martha. The girls are soon dismayed to find they are legally bound to their new masters for a year. Sir Tristan is unable to retrieve them from their fate. Quickly, both farmers fall for their new maidservants — Lyonel for Harriet and Plunkett for Nancy. Harriet feels that Lyonel
1232-580: A few " telephone newspaper " systems, most of which were established in Europe, beginning with the Paris Théâtrophone . With this in mind, most early radiotelephone development envisioned that the device would be more profitably developed as a "wireless telephone" for personal communication, or for providing links where regular telephone lines could not be run, rather than for the uncertain finances of broadcasting. The person generally credited as
SECTION 10
#17327983204551344-463: A few hundred ( Hz ), to increase its rotational speed and so generate currents of tens-of-thousands Hz, thus producing a steady continuous-wave transmission when connected to an aerial. The next step, adopted from standard wire-telephone practice, was to insert a simple carbon microphone into the transmission line, to modulate the carrier wave signal to produce AM audio transmissions. However, it would take many years of expensive development before even
1456-585: A fresh boost in popularity in 1906 when it was staged at the Metropolitan Opera in New York in a production that featured the famed tenor Enrico Caruso , singing the opera in Italian. Lyonel was one of Caruso's most popular roles, performing it many times during subsequent seasons; he also recorded several extracts from the Italian version of the opera. Martha fell out of favor by the 1920s and it
1568-516: A home audio device prior to the introduction of the high-fidelity , long-playing record in the late 1940s. Listening habits changed in the 1960s due to the introduction of the revolutionary transistor radio (Regency TR-1, the first transistor radio released December 1954), which was made possible by the invention of the transistor in 1948. (The transistor was invented at Bell labs and released in June 1948.) Their compact size — small enough to fit in
1680-474: A listening site at Plymouth, Massachusetts. An American Telephone Journal account of the December 21 alternator-transmitter demonstration included the statement that "It is admirably adapted to the transmission of news, music, etc. as, owing to the fact that no wires are needed, simultaneous transmission to many subscribers can be effected as easily as to a few", echoing the words of a handout distributed to
1792-487: A majority of early broadcasting stations operated on mediumwave frequencies, whose limited range generally restricted them to local audiences. One method for overcoming this limitation, as well as a method for sharing program costs, was to create radio networks , linking stations together with telephone lines to provide a nationwide audience. In the U.S., the American Telephone and Telegraph Company (AT&T)
1904-401: A melancholy state. Wandering in the forest, Lyonel meets a royal hunting party and recognises Lady Harriet. He declares his love for her, but she rebuffs him. Lyonel reminds her of her contract to serve him for a year. She tells the party the young man is mad, and Sir Tristan supports her declaration. Orders are given to imprison the young man. Lyonel has a ring his father gave him, saying if he
2016-447: A mix of local and national conservative talk programs, branded as "KLZ Radio." Local shows are largely paid brokered programming . Topics include money and investing, real estate and health. Nationally syndicated programs include The Dana Loesch Show and The Mike Gallagher Show . While religious radio shows are only broadcast on Sunday mornings on KLZ, Crawford Broadcasting owns two Christian talk and teaching stations in
2128-506: A national scale. The introduction of nationwide talk shows, most prominently Rush Limbaugh 's beginning in 1988, was sometimes credited with "saving" AM radio. However, these stations tended to attract older listeners who were of lesser interest to advertisers, and AM radio's audience share continued to erode. In 1961, the FCC adopted a single standard for FM stereo transmissions, which was widely credited with enhancing FM's popularity. Developing
2240-518: A period called the " Golden Age of Radio ", until television broadcasting became widespread in the 1950s and received much of the programming previously carried by radio. Later, AM radio's audiences declined greatly due to competition from FM ( frequency modulation ) radio, Digital Audio Broadcasting (DAB), satellite radio , HD (digital) radio , Internet radio , music streaming services , and podcasting . Compared to FM or digital transmissions , AM transmissions are more expensive to transmit due to
2352-399: A policy allowing AM stations to simulcast over FM translator stations. Translators had previously been available only to FM broadcasters, in order to increase coverage in fringe areas. Their assignment for use by AM stations was intended to approximate the station's daytime coverage, which in cases where the stations reduced power at night, often resulted in expanded nighttime coverage. Although
SECTION 20
#17327983204552464-486: A prototype alternator-transmitter would be ready, and a few years beyond that for high-power versions to become available. Fessenden worked with General Electric 's (GE) Ernst F. W. Alexanderson , who in August 1906 delivered an improved model which operated at a transmitting frequency of approximately 50 kHz, although at low power. The alternator-transmitter achieved the goal of transmitting quality audio signals, but
2576-423: A result, AM radio tends to do best in areas where FM frequencies are in short supply, or in thinly populated or mountainous areas where FM coverage is poor. Great care must be taken to avoid mutual interference between stations operating on the same frequency. In general, an AM transmission needs to be about 20 times stronger than an interfering signal to avoid a reduction in quality, in contrast to FM signals, where
2688-452: A shirt pocket — and lower power requirements, compared to vacuum tubes, meant that for the first time radio receivers were readily portable. The transistor radio became the most widely used communication device in history, with billions manufactured by the 1970s. Radio became a ubiquitous "companion medium" which people could take with them anywhere they went. The demarcation between what is considered "experimental" and "organized" broadcasting
2800-427: A short-range "wireless telephone" demonstration, that included simultaneously broadcasting speech and music to seven locations throughout Murray, Kentucky. However, this was transmitted using induction rather than radio signals, and although Stubblefield predicted that his system would be perfected so that "it will be possible to communicate with hundreds of homes at the same time", and "a single message can be sent from
2912-458: A slow A minor introduction, but changes suddenly to an A major theme (that of Lyonel's prayer in act 3, "Mag der Himmel Euch vergeben"), presented as an extended French horn solo with orchestral accompaniment that concludes with the theme stated by the full orchestra. It reverts to A minor with a busy, agitated motif for the Allegro, representing Lady Harriet and Nancy bustling about, leading into
3024-599: A tragic conclusion, but rather the lovers' dilemmas and local color. Though the powerful overture hints at a darker outcome, the opera ends happily. The heroine's levity and Lyonel's sincerity are its themes. The dramatic music, as between Lyonel and Harriet in act 4, is weighty, while the scoring of the comic scenes is also (but differently) effective. In his own idiom, like Mozart in Don Giovanni or Verdi in Un ballo in maschera , von Flotow could build convivial music into
3136-418: A tragic dramatic context. The Thomas Moore traditional Irish melody " The Last Rose of Summer ", introduced for Martha in act 2, was a successful inclusion. Popular airs were then often introduced informally to operas as show-pieces by sopranos, for example " Home! Sweet Home! " in the lesson scene of The Barber of Seville . Singers such as Jenny Lind or Adelina Patti made much of them. In Martha
3248-461: A widespread audience — dates back to the founding period of radio development, even though the earliest radio transmissions, originally known as "Hertzian radiation" and "wireless telegraphy", used spark-gap transmitters that could only transmit the dots-and-dashes of Morse code . In October 1898 a London publication, The Electrician , noted that "there are rare cases where, as Dr. [Oliver] Lodge once expressed it, it might be advantageous to 'shout'
3360-456: Is blinded by anger with Harriet for the injustice she did him and refuses to accept her love. To win him back, Harriet and Nancy return to the fair once again dressed as country wenches. When Plunkett brings Lyonel to the fair and points out the two pretty serving-maids, Lyonel realises he does love Harriet. He embraces her, and they agree to marry, as do Plunkett and Nancy. The overture is among von Flotow's most appreciated works. It begins with
3472-406: Is comparable to or better in audio quality than a standard analog broadcast". Despite the various actions, AM band audiences continued to contract, and the number of stations began to slowly decline. A 2009 FCC review reported that "The story of AM radio over the last 50 years has been a transition from being the dominant form of audio entertainment for all age groups to being almost non-existent to
KLZ - Misplaced Pages Continue
3584-502: Is largely arbitrary. Listed below are some of the early AM radio broadcasts, which, due to their irregular schedules and limited purposes, can be classified as "experimental": People who weren't around in the Twenties when radio exploded can't know what it meant, this milestone for mankind. Suddenly, with radio, there was instant human communication. No longer were our homes isolated and lonely and silent. The world came into our homes for
3696-412: Is of higher station than he appears. He is an orphan who was left with Plunkett's parents in early childhood. The new maids are totally inept at their tasks, which infuriates Plunkett. Finally, the new maids are told to go to bed, but escape through the window, with the aid of Sir Tristan. The young farmers are distressed and angry at the loss of their maids, and Lyonel's grief is so great that he falls into
3808-645: Is simpler than later transmission systems. An AM receiver detects amplitude variations in the radio waves at a particular frequency, then amplifies changes in the signal voltage to operate a loudspeaker or earphone . However, the simplicity of AM transmission also makes it vulnerable to "static" ( radio noise , radio frequency interference ) created by both natural atmospheric electrical activity such as lightning, and electrical and electronic equipment, including fluorescent lights, motors and vehicle ignition systems. In large urban centers, AM radio signals can be severely disrupted by metal structures and tall buildings. As
3920-578: The Electronic Industries Association (EIA) and the National Association of Broadcasters (NAB) with the intention of helping AM stations, especially ones with musical formats, become more competitive with FM broadcasters by promoting better quality receivers. However, the stereo AM and AMAX initiatives had little impact, and a 2015 review of these events concluded that Initially the consumer manufacturers made
4032-625: The Emergency Alert System (EAS). Some automakers have been eliminating AM radio from their electric vehicles (EVs) due to interference from the electric motors , but the lawmakers argue that this is a safety risk and that car owners should have access to AM radio regardless of the type of vehicle they drive. The proposed legislation would require all new vehicles to include AM radio at no additional charge, and it would also require automakers that have already eliminated AM radio to inform customers of alternatives. AM radio technology
4144-493: The Federal Emergency Management Agency (FEMA) expressed concerns that this would reduce the effectiveness of emergency communications. In May 2023, a bipartisan group of lawmakers in the United States introduced legislation making it illegal for automakers to eliminate AM radio from their cars. The lawmakers argue that AM radio is an important tool for public safety due to being a component of
4256-1080: The July Revolution returned there from 1835 until 1848, and again from 1863 until 1868.) The first performance of Martha took place at the Kärntnertortheater in Vienna on 25 November 1847. Other early productions followed in Weimar (16 February 1848), Dresden (1 March 1848), Leipzig (1 March 1848), and Berlin (7 March 1848). It was performed in Budapest in Hungarian (11 July 1848) and in Prague in German (24 March 1849) and in Czech (17 February 1850). There were several early productions in London,
4368-431: The electrolytic detector and thermionic diode ( Fleming valve ) were invented by Reginald Fessenden and John Ambrose Fleming , respectively. Most important, in 1904–1906 the crystal detector , the simplest and cheapest AM detector, was developed by G. W. Pickard . Homemade crystal radios spread rapidly during the next 15 years, providing ready audiences for the first radio broadcasts. One limitation of crystals sets
4480-430: The " capture effect " means that the dominant signal needs to only be about twice as strong as the interfering one. To allow room for more stations on the mediumwave broadcast band in the United States, in June 1989 the FCC adopted a National Radio Systems Committee (NRSC) standard that limited maximum transmitted audio bandwidth to 10.2 kHz, limiting occupied bandwidth to 20.4 kHz. The former audio limitation
4592-603: The 1930s, most of the major radio stations in the country were affiliated with networks owned by two companies, NBC and CBS . In 1934, a third national network, the Mutual Radio Network , was formed as a cooperative owned by its stations. A second country which quickly adopted network programming was the United Kingdom, and its national network quickly became a prototype for a state-managed monopoly of broadcasting. A rising interest in radio broadcasting by
KLZ - Misplaced Pages Continue
4704-660: The 1940s two new broadcast media, FM radio and television , began to provide extensive competition with the established broadcasting services. The AM radio industry suffered a serious loss of audience and advertising revenue, and coped by developing new strategies. Network broadcasting gave way to format broadcasting: instead of broadcasting the same programs all over the country, stations individually adopted specialized formats which appealed to different audiences, such as regional and local news, sports, "talk" programs, and programs targeted at minorities. Instead of live music, most stations began playing less expensive recorded music. In
4816-532: The AM radio industry in the United States developed technology for broadcasting in stereo . Other nations adopted AM stereo, most commonly choosing Motorola's C-QUAM, and in 1993 the United States also made the C-QUAM system its standard, after a period allowing four different standards to compete. The selection of a single standard improved acceptance of AM stereo , however overall there was limited adoption of AM stereo worldwide, and interest declined after 1990. With
4928-531: The British public pressured the government to reintroduce the service, following its suspension in 1920. However, the government also wanted to avoid what it termed the "chaotic" U.S. experience of allowing large numbers of stations to operate with few restrictions. There were also concerns about broadcasting becoming dominated by the Marconi company. Arrangements were made for six large radio manufacturers to form
5040-610: The Denver area, 810 KLVZ and 1220 KLDC . KLZ describes itself several times each hour as "God and Country" radio. KLZ was first licensed as a broadcasting station on March 10, 1922, to the Reynolds Radio Company of Denver, Colorado. The company's president, Dr. William D. "Doc" Reynolds Jr., had earlier experimented with radio broadcasts, and the station traditionally traces its founding to 1919 or 1920. In September 1915, Reynolds, then living in Minneapolis ,
5152-520: The Reynolds Radio Company applied for the appropriate license, and on March 10, 1922, a broadcasting station authorization – the first in the state of Colorado – with the randomly assigned call letters of KLZ was issued to the company. KLZ was given permission to use both of the broadcasting wavelengths established by the new regulations: 360 meters (833 kHz) for "entertainment" broadcasts, and 485 meters (619 kHz) for "market and weather" reports. (Reynolds' amateur radio transmissions, although using
5264-619: The Reynolds Radio Specialty Co.) After moving to Denver, Reynolds joined with other radio enthusiasts in making a number of "mobile" demonstrations, where radio-receiver equipped automobiles picked up special programs. He participated in the May 19, 1921, broadcast of the opera Martha from the Denver Municipal Auditorium . In the summer of 1921, Reynolds was issued a "Special Amateur" license, with
5376-613: The Reynolds Radio Specialty Company, which was located at his home on South Prospect Street. The following February, another newspaper article stated that he had been broadcasting regular Sunday evening concerts. The article also said Reynolds was making plans to move his family and his company to Denver. (Reflecting this change, the Commerce Department's June 1921 amateur station call book entry for 9JE lists its new location as Denver, operated by
5488-411: The Twenties when radio exploded can't know what it meant, this milestone for mankind. Suddenly, with radio, there was instant human communication. No longer were our homes isolated and lonely and silent. The world came into our homes for the first time. Music came pouring in. Laughter came in. News came in. The world shrank, with radio. The idea of broadcasting — the unrestricted transmission of signals to
5600-411: The U.S., for example) subject to international agreements. Martha (opera) Martha, oder Der Markt zu Richmond ( Martha, or The Market at Richmond ) is a romantic comic opera in four acts by Friedrich von Flotow set to a German libretto by Friedrich Wilhelm Riese [ de ] and based on a story by Jules-Henri Vernoy de Saint-Georges . Flotow had composed the first act of
5712-694: The United States and France this led to a small market of receiver lines geared for jewelers who needed accurate time to set their clocks, including the Ondophone in France, and the De Forest RS-100 Jewelers Time Receiver in the United States The ability to pick up time signal broadcasts, in addition to Morse code weather reports and news summaries, also attracted the interest of amateur radio enthusiasts. It
SECTION 50
#17327983204555824-523: The antenna wire. This meant that the full transmitter power flowed through the microphone, and even using water cooling, the power handling ability of the microphones severely limited the power of the transmissions. Ultimately only a small number of large and powerful Alexanderson alternators would be developed. However, they would be almost exclusively used for long-range radiotelegraph communication, and occasionally for radiotelephone experimentation, but were never used for general broadcasting. Almost all of
5936-482: The audience has continued to decline. In 1987, the elimination of the Fairness Doctrine requirement meant that talk shows, which were commonly carried by AM stations, could adopt a more focused presentation on controversial topics, without the distraction of having to provide airtime for any contrasting opinions. In addition, satellite distribution made it possible for programs to be economically carried on
6048-408: The call sign 9ZAF. This allowed transmissions on 370 meters (811 kHz), a wavelength with less interference than 9JE had encountered on the congested standard amateur wavelength of 200 meters (1500 kHz). In addition to experimental broadcasts, 9ZAF acted as a "relay station" for coast-to-coast messages passing through a cooperative network of Amateur Radio Relay League stations. In October, it
6160-404: The characteristics of arc-transmitters . Fessenden attempted to sell this form of radiotelephone for point-to-point communication, but was unsuccessful. Fessenden's work with high-frequency spark transmissions was only a temporary measure. His ultimate plan for creating an audio-capable transmitter was to redesign an electrical alternator , which normally produced alternating current of at most
6272-403: The commission estimated that fewer than 250 AM stations were transmitting hybrid mode signals. On October 27, 2020, the FCC voted to allow AM stations to eliminate their analog transmissions and convert to all-digital operation, with the requirement that stations making the change had to continue to make programming available over "at least one free over-the-air digital programming stream that
6384-475: The continued migration of AM stations away from music to news, sports, and talk formats, receiver manufacturers saw little reason to adopt the more expensive stereo tuners, and thus radio stations have little incentive to upgrade to stereo transmission. In countries where the use of directional antennas is common, such as the United States, transmitter sites consisting of multiple towers often occupy large tracts of land that have significantly increased in value over
6496-437: The continuous wave AM transmissions made prior to 1915 were made by versions of the arc converter transmitter, which had been initially developed by Valdemar Poulsen in 1903. Arc transmitters worked by producing a pulsating electrical arc in an enclosed hydrogen atmosphere. They were much more compact than alternator transmitters, and could operate on somewhat higher transmitting frequencies. However, they suffered from some of
6608-452: The country. But she becomes bored so she decides to attend the fair at Richmond where girls hire themselves out as servants. For a laugh, she and her confidante Nancy masquerade as maidservants. Her foppish old cousin, Sir Tristan, another admirer whom she deems a bore, accompanies them. Harriet manages to lose her escort, and then she and Nancy stand in the line of girls waiting to be hired. Two young farmers, Lyonel and Plunkett, are looking for
6720-548: The date of the first performance at the Théâtre Lyrique as 16 December 1865. He also challenges Kobbé's statement that the aria "M'appari" (which Flotow composed for his earlier opera L'âme en peine ) was first introduced into the opera Martha at that theatre. He notes that it was sung by Mario at the Théâtre-Italien in 1858 and is also found (as "Ach! so fromm") in an early (probably 1848) Vienna edition of
6832-434: The decades, to the point that the value of land exceeds that of the station itself. This sometimes results in the sale of the transmitter site, with the station relocating to a more distant shared site using significantly less power, or completely shutting down operations. The ongoing development of alternative transmission systems, including Digital Audio Broadcasting (DAB), satellite radio, and HD (digital) radio, continued
SECTION 60
#17327983204556944-567: The decline of the popularity of the traditional broadcast technologies. These new options, including the introduction of Internet streaming, particularly resulted in the reduction of shortwave transmissions, as international broadcasters found ways to reach their audiences more easily. In 2022 it was reported that AM radio was being removed from a number of electric vehicle (EV) models, including from cars manufactured by Tesla, Audi, Porsche, BMW and Volvo, reportedly due to automakers concerns that an EV's higher electromagnetic interference can disrupt
7056-569: The demonstration witnesses, which stated "[Radio] Telephony is admirably adapted for transmitting news, stock quotations, music, race reports, etc. simultaneously over a city, on account of the fact that no wires are needed and a single apparatus can distribute to ten thousand subscribers as easily as to a few. It is proposed to erect stations for this purpose in the large cities here and abroad." However, other than two holiday transmissions reportedly made shortly after these demonstrations, Fessenden does not appear to have conducted any radio broadcasts for
7168-595: The entertainment, and they were later joined by their young son. KLZ's studios later moved to the Shirley-Savoy Hotel (Savoy opened in 1904; Shirley opened in 1903; joined in 1919; razed in 1970), with the station antenna constructed atop the building. In 1927, the Federal Radio Commission was formed to regulate radio stations in the United States. It embarked on a major restructuring of the broadcast band, and, on November 11, 1928, under
7280-504: The equipment provided by the Forestry service to experiment with entertainment broadcasts, and one of his first radiotelephone tests, in May 1920, provided musical selections for a dance held by students at a local high school. In late October 1920, a newspaper account stated that Reynolds was broadcasting nightly concerts. This report also noted he had decided to suspend his dental practice to devote full-time attention to radio. He founded
7392-648: The expectation is that listeners will primarily be tuning into the FM signal rather than the nominally "primary" AM station. A 2020 review noted that "for many owners, keeping their AM stations on the air now is pretty much just about retaining their FM translator footprint rather than keeping the AM on the air on its own merits". In 2018 the FCC, led by then-Commission Chairman Ajit Pai , proposed greatly reducing signal protection for 50 kW Class A " clear channel " stations. This would allow co-channel secondary stations to operate with higher powers, especially at night. However,
7504-445: The fall of 1900, he successfully transmitted speech over a distance of about 1.6 kilometers (one mile), which appears to have been the first successful audio transmission using radio signals. However, at this time the sound was far too distorted to be commercially practical. For a time he continued working with more sophisticated high-frequency spark transmitters, including versions that used compressed air, which began to take on some of
7616-648: The first in German at Drury Lane (4 June 1849), followed by one in Italian at Covent Garden (1 July 1858) and another in English at Drury Lane (11 October 1858). In the United States, it was produced in English at Niblo's Garden in New York City on 1 November 1852 with Anna Bishop , in New Orleans on 27 January 1860, in French. It had its first Australian performance in Melbourne on 24 June 1856. The opera
7728-401: The first time. Music came pouring in. Laughter came in. News came in. The world shrank, with radio. Following World War I, the number of stations providing a regular broadcasting service greatly increased, primarily due to advances in vacuum-tube technology. In response to ongoing activities, government regulators eventually codified standards for which stations could make broadcasts intended for
7840-624: The general public, for example, in the United States formal recognition of a "broadcasting service" came with the establishment of regulations effective December 1, 1921, and Canadian authorities created a separate category of "radio-telephone broadcasting stations" in April 1922. However, there were numerous cases of entertainment broadcasts being presented on a regular schedule before their formal recognition by government regulators. Some early examples include: Because most longwave radio frequencies were used for international radiotelegraph communication,
7952-417: The general public, or to have even given additional thought about the potential of a regular broadcast service, and in a 1908 article providing a comprehensive review of the potential uses for his radiotelephone invention, he made no references to broadcasting. Because there was no way to amplify electrical currents at this time, modulation was usually accomplished by a carbon microphone inserted directly in
8064-554: The isolation of rural life. Political officials could now speak directly to millions of citizens. One of the first to take advantage of this was American president Franklin Roosevelt , who became famous for his fireside chats during the Great Depression . However, broadcasting also provided the means to use propaganda as a powerful government tool, and contributed to the rise of fascist and communist ideologies. In
8176-411: The lack of any way to amplify the signals meant they were somewhat weak. On December 21, 1906, Fessenden made an extensive demonstration of the new alternator-transmitter at Brant Rock, Massachusetts, showing its utility for point-to-point wireless telephony, including interconnecting his stations to the wire telephone network. As part of the demonstration, speech was transmitted 18 kilometers (11 miles) to
8288-419: The late 1960s and 1970s, top 40 rock and roll stations in the U.S. and Canada such as WABC and CHUM transmitted highly processed and extended audio to 11 kHz, successfully attracting huge audiences. For young people, listening to AM broadcasts and participating in their music surveys and contests was the social media of the time. In the late 1970s, spurred by the exodus of musical programming to FM stations,
8400-399: The marketplace decide" which was best. The lack of a common standard resulted in consumer confusion and increased the complexity and cost of producing AM stereo receivers. In 1993, the FCC again revised its policy, by selecting C-QUAM as the sole AM stereo implementation. In 1993, the FCC also endorsed, although it did not make mandatory, AMAX broadcasting standards that were developed by
8512-432: The message, spreading it broadcast to receivers in all directions". However, it was recognized that this would involve significant financial issues, as that same year The Electrician also commented "did not Prof. Lodge forget that no one wants to pay for shouting to the world on a system by which it would be impossible to prevent non-subscribers from benefiting gratuitously?" On January 1, 1902, Nathan Stubblefield gave
8624-448: The multiple incompatible AM stereo systems, and failure of the manufacturers (including the auto makers) to effectively promote AMAX radios, coupled with the ever-increasing background of noise in the band, the general public soon lost interest and moved on to other media. On June 8, 1988, an International Telecommunication Union (ITU)-sponsored conference held at Rio de Janeiro, Brazil adopted provisions, effective July 1, 1990, to extend
8736-537: The necessity of having to transmit a high power carrier wave to overcome ground losses, and the large antenna radiators required at the low broadcast frequencies, but can be sent over long distances via the ionosphere at night; however, they are much more susceptible to interference, and often have lower audio fidelity. Thus, AM broadcasters tend to specialize in spoken-word formats, such as talk radio , all-news radio and sports radio , with music formats primarily for FM and digital stations. People who weren't around in
8848-405: The new frequencies. It was now estimated that the expanded band could accommodate around 300 U.S. stations. However, it turned out that the number of possible station reassignments was much lower, with a 2006 accounting reporting that, out of 4,758 licensed U.S. AM stations, only 56 were now operating on the expanded band. Moreover, despite an initial requirement that by the end of five years either
8960-428: The new policy, by 2011 there were approximately 500 in operation, and as of 2020 approximately 2,800 of the 4,570 licensed AM stations were rebroadcasting on one or more FM translators. In 2009 the FCC stated that "We do not intend to allow these cross-service translators to be used as surrogates for FM stations". However, based on station slogans, especially in the case of recently adopted musical formats, in most cases
9072-644: The oboes, clarinets, and cellos in the midst of the orchestral texture, adding winds and brass to the theme in a crescendo until suddenly breaking off and reprising the peasant girls' chorus in A major. That leads without further modulation back to the Lyonel's prayer motif for full orchestra as in the beginning, and so the overture ends with a brisk, very short duple-meter coda. The fluctuations of light and shade are reminiscent of Schubertian scoring, or of Weber (e.g. Der Freischütz overture): but without modulation into remote tonalities, they never really portend
9184-411: The original station or its expanded band counterpart had to cease broadcasting, as of 2015 there were 25 cases where the original standard band station was still on the air, despite also operating as an expanded band station. HD Radio is a digital audio broadcasting method developed by iBiquity . In 2002 its "hybrid mode", which simultaneously transmits a standard analog signal as well as a digital one,
9296-433: The overheating issues of needing to insert microphones directly in the transmission antenna circuit. Vacuum tube transmitters also provided high-quality AM signals, and could operate on higher transmitting frequencies than alternator and arc transmitters. Non-governmental radio transmissions were prohibited in many countries during World War I, but AM radiotelephony technology advanced greatly due to wartime research, and after
9408-441: The primary early developer of AM technology is Canadian-born inventor Reginald Fessenden . The original spark-gap radio transmitters were impractical for transmitting audio, since they produced discontinuous pulses known as " damped waves ". Fessenden realized that what was needed was a new type of radio transmitter that produced steady "undamped" (better known as " continuous wave ") signals, which could then be "modulated" to reflect
9520-559: The provisions of General Order 40 , KLZ was assigned to operate on 560 kHz, which it has continued to use ever since. This assignment specified a transmitting power of 1,000 watts, then the maximum permitted for stations operating on a "regional" frequency. KLZ was later able to take advantage of the adoption of higher limits, eventually increasing its power to 5,000 watts, its current rating. Dr. Reynolds died in November 1931, and KLZ signed off for three hours in his memory. In 2014, he
9632-650: The reception of AM transmissions and hurt the listening experience, among other reasons. However the United States Congress has introduced a bill to require all vehicles sold in the US to have an AM receiver to receive emergency broadcasts. The FM broadcast band was established in 1941 in the United States, and at the time some suggested that the AM band would soon be eliminated. In 1948 wide-band FM's inventor, Edwin H. Armstrong , predicted that "The broadcasters will set up FM stations which will parallel, carry
9744-799: The same deficiencies. The lack of any means to amplify electrical currents meant that, like the alternator transmitters, modulation was usually accomplished by a microphone inserted directly in the antenna wire, which again resulted in overheating issues, even with the use of water-cooled microphones. Thus, transmitter powers tended to be limited. The arc was also somewhat unstable, which reduced audio quality. Experimenters who used arc transmitters for their radiotelephone research included Ernst Ruhmer , Quirino Majorana , Charles "Doc" Herrold , and Lee de Forest . Advances in vacuum tube technology (called "valves" in British usage), especially after around 1915, revolutionized radio technology. Vacuum tube devices could be used to amplify electrical currents, which overcame
9856-536: The same equipment as KLZ, continued as 9ZAF on 370 meters). In late March, the Rocky Mountain News reported the station's schedule as "KLZ (ex-9ZAF), News-Times-Reynolds service begins broadcasting news, market reports, and concerts and a good-night story for the children at 7:30 p.m. Sermons and music Sundays from 8:00 to 9:30 p.m. at 360 meters" in addition to "Market reports and financial news daily at 12:30 noon,[sic] except Sundays, at 485 meters". KLZ
9968-400: The same program, as over their AM stations... eventually the day will come, of course, when we will no longer have to build receivers capable of receiving both types of transmission, and then the AM transmitters will disappear." However, FM stations actually struggled for many decades, and it was not until 1978 that FM listenership surpassed that of AM stations. Since then the AM band's share of
10080-718: The score in the British Library and was probably always a part of the opera. The confusion may have arisen from further alterations made by the Théâtre Lyrique's director, Léon Carvalho , which included the insertion in act 4 of Flotow's baritone aria "Depuis le jour j'ai paré ma chaumière" (also from L'âme en peine ). In 1877, at the Royal Italian Opera in Covent Garden, Victor Capoul performed as Lyonel, with Francesco Graziani (baritone) as Plunkett and Sofia Scalchi as Nancy. Martha received
10192-430: The slightly slower ( meno moto ) C major peasant girls' chorus theme from act 1, played by woodwinds accompanied by triangle and snare drum with pizzicato string punctuation. This concludes with a mini- coda for the full orchestra a tempo in C; then the agitated theme returns, but modulates several times from C through D minor and E minor to a section pitting the agitated theme in F major against Lyonel's prayer in
10304-410: The sounds being transmitted. Fessenden's basic approach was disclosed in U.S. Patent 706,737, which he applied for on May 29, 1901, and was issued the next year. It called for the use of a high-speed alternator (referred to as "an alternating-current dynamo") that generated "pure sine waves" and produced "a continuous train of radiant waves of substantially uniform strength", or, in modern terminology,
10416-515: The station as the "News-Times-Reynolds Broadcasting station". Initially, there were no formal restrictions about which radio station license categories could make broadcasts intended for the general public. However, effective December 1, 1921, the Department of Commerce, which regulated U.S. radio at this time, adopted a regulation that stations making general broadcasts now had to hold a Limited Commercial license. To comply with this new standard,
10528-411: The technology for AM broadcasting in stereo was challenging due to the need to limit the transmissions to a 20 kHz bandwidth, while also making the transmissions backward compatible with existing non-stereo receivers. In 1990, the FCC authorized an AM stereo standard developed by Magnavox, but two years later revised its decision to instead approve four competing implementations, saying it would "let
10640-401: The translator stations are not permitted to originate programming when the "primary" AM station is broadcasting, they are permitted to do so during nighttime hours for AM stations licensed for daytime-only operation. Prior to the adoption of the new policy, as of March 18, 2009, the FCC had issued 215 Special Temporary Authority grants for FM translators relaying AM stations. After creation of
10752-496: The upper end of the Region 2 AM broadcast band, by adding ten frequencies which spanned from 1610 kHz to 1700 kHz. At this time it was suggested that as many as 500 U.S. stations could be assigned to the new frequencies. On April 12, 1990, the FCC voted to begin the process of populating the expanded band, with the main priority being the reduction of interference on the existing AM band, by transferring selected stations to
10864-548: The war the availability of tubes sparked a great increase in the number of amateur radio stations experimenting with AM transmission of news or music. Vacuum tubes remained the central technology of radio for 40 years, until transistors began to dominate in the late 1950s, and are still used in the highest power broadcast transmitters. Unlike telegraph and telephone systems, which used completely different types of equipment, most radio receivers were equally suitable for both radiotelegraph and radiotelephone reception. In 1903 and 1904
10976-404: The youngest demographic groups. Among persons aged 12–24, AM accounts for only 4% of listening, while FM accounts for 96%. Among persons aged 25–34, AM accounts for only 9% of listening, while FM accounts for 91%. The median age of listeners to the AM band is 57 years old, a full generation older than the median age of FM listeners." In 2009, the FCC made a major regulatory change, when it adopted
11088-572: Was 15 kHz resulting in bandwidth of 30 kHz. Another common limitation on AM fidelity is the result of receiver design, although some efforts have been made to improve this, notably through the AMAX standards adopted in the United States. AM broadcasts are used on several frequency bands. The allocation of these bands is governed by the ITU 's Radio Regulations and, on the national level, by each country's telecommunications administration (the FCC in
11200-493: Was an adaptation of this ballet. According to Gustav Kobbé , Martha , though written by a native of Mecklenburg and first performed in Vienna, is French in character and elegance. Flotow was French in his musical training, as were the origins of both the plot and the score of this work, effectively in the tradition of Auber . (Flotow studied composition in Paris under Reicha from 1827 until 1830, and having left on account of
11312-482: Was announced that 9ZAF's equipment had been upgraded, and, in addition to Sunday evening concerts from 8:00 to 9:30 pm, the station was broadcasting daily weather forecasts twice a day, at 8:30 a.m. and 9:00 pm. In early 1922, the Rocky Mountain News announced it was providing news bulletins as a supplement to the nightly station concerts. The paper also started promoting 9ZAF, referring to
11424-474: Was approved by the FCC for use by AM stations, initially only during daytime hours, due to concerns that during the night its wider bandwidth would cause unacceptable interference to stations on adjacent frequencies. In 2007 nighttime operation was also authorized. The number of hybrid mode AM stations is not exactly known, because the FCC does not keep track of the stations employing the system, and some authorized stations have later turned it off. But as of 2020
11536-419: Was ended and Reynolds, who had subsequently moved to Colorado Springs, relicensed his amateur station, which was now issued the call sign of 9JE. During the war, vacuum tube radio transmitters had been developed that made audio transmissions practical. Reynolds began work with the U.S. Forestry Service to evaluate the practicality of using radiotelephones to aid department communication. He also took advantage of
11648-540: Was ever in trouble he was to send the ring to the Queen. He begs his friend to take it to the court. The ring saves Lyonel. The Queen recognises it as that of a banished nobleman, whose innocence has since been proven. Lady Harriet is now willing to accept his courtship as there is no longer a class difference to stand between them. She is filled with remorse for the way she has treated him. She reveals to him her true identity and tells him that his estate will be restored but he
11760-400: Was immediately recognized that, much like the telegraph had preceded the invention of the telephone, the ability to make audio radio transmissions would be a significant technical advance. Despite this knowledge, it still took two decades to perfect the technology needed to make quality audio transmissions. In addition, the telephone had rarely been used for distributing entertainment, outside of
11872-476: Was inducted into the Broadcast Pioneers of Colorado's "Broadcast Pioneers Hall of Fame". AM broadcasting The earliest experimental AM transmissions began in the early 1900s. However, widespread AM broadcasting was not established until the 1920s, following the development of vacuum tube receivers and transmitters. AM radio remained the dominant method of broadcasting for the next 30 years,
11984-451: Was initially located at Reynolds' home at 1124 South University Boulevard in Denver. Two 80-foot (25-meter) towers had been erected, one in front of the house and the other behind, to support a large "flat-top" transmitting antenna and counterpoise. A room in the house was set aside as a studio and also housed the station's transmitter. Initially Reynolds – who played saxophone and violin – and his wife Naomi – who played piano – provided much of
12096-401: Was issued his first license for an amateur radio station with the call sign 9WH. This initial station employed a spark transmitter that could only transmit the dots-and-dashes of Morse code . With the entrance of the United States into World War I in April 1917, all civilian radio stations were ordered to cease operations for the duration of the conflict. In late 1919 the amateur radio ban
12208-614: Was performed at the second inauguration of Abraham Lincoln in 1865. It was first performed in France in Italian by the Théâtre-Italien at the Salle Ventadour in Paris on 11 February 1858 and in French at several provincial theatres beginning in December 1858 and at the Théâtre Lyrique in Paris on 18 December 1865. According to T. J. Walsh , numerous editions of Kobbé's Opera Book have incorrectly given
12320-429: Was rarely performed for decades thereafter. Interest in the opera was rekindled by the 1980s and recent productions in the United Kingdom have included those by Opera South in 1986 and 2009 and Bel Canto Opera in 2002. Those in the U.S. have included Michigan Opera Theatre in 1985. Lady Harriet Durham, a maid-of-honour to Queen Anne, is so tired of Court life, and so sick of her many insipid admirers, she retires to
12432-473: Was the first organization to create a radio network, and also to promote commercial advertising, which it called "toll" broadcasting. Its flagship station, WEAF (now WFAN) in New York City, sold blocks of airtime to commercial sponsors that developed entertainment shows containing commercial messages . AT&T held a monopoly on quality telephone lines, and by 1924 had linked 12 stations in Eastern cities into
12544-406: Was the lack of amplifying the signals, so listeners had to use earphones , and it required the development of vacuum-tube receivers before loudspeakers could be used. The dynamic cone loudspeaker , invented in 1924, greatly improved audio frequency response over the previous horn speakers, allowing music to be reproduced with good fidelity. AM radio offered the highest sound quality available in
#454545