Radio broadcasting is transmission by radio waves intended to reach a wide audience. Stations can be linked in radio networks to broadcast a common radio format, either in broadcast syndication or simulcast or both; the signal types can be digital audio. The earliest radio stations did not carry audio. For audio broadcasts to be possible, electronic detection and amplification devices had to be incorporated; the thermionic valve was invented in 1904 by the English physicist John Ambrose Fleming. He developed a device he called an "oscillation valve"; the heated filament, or cathode, was capable of thermionic emission of electrons that would flow to the plate when it was at a higher voltage. Electrons, could not pass in the reverse direction because the plate was not heated and thus not capable of thermionic emission of electrons. Known as the Fleming valve, it could be used as a rectifier of alternating current and as a radio wave detector; this improved the crystal set which rectified the radio signal using an early solid-state diode based on a crystal and a so-called cat's whisker.
However, what was still required was an amplifier. The triode was patented on March 4, 1906, by the Austrian Robert von Lieben independent from that, on October 25, 1906, Lee De Forest patented his three-element Audion, it wasn't put to practical use until 1912 when its amplifying ability became recognized by researchers. By about 1920, valve technology had matured to the point where radio broadcasting was becoming viable. However, an early audio transmission that could be termed a broadcast may have occurred on Christmas Eve in 1906 by Reginald Fessenden, although this is disputed. While many early experimenters attempted to create systems similar to radiotelephone devices by which only two parties were meant to communicate, there were others who intended to transmit to larger audiences. Charles Herrold started broadcasting in California in 1909 and was carrying audio by the next year.. In The Hague, the Netherlands, PCGG started broadcasting on November 6, 1919, making it, arguably the first commercial broadcasting station.
In 1916, Frank Conrad, an electrical engineer employed at the Westinghouse Electric Corporation, began broadcasting from his Wilkinsburg, Pennsylvania garage with the call letters 8XK. The station was moved to the top of the Westinghouse factory building in East Pittsburgh, Pennsylvania. Westinghouse relaunched the station as KDKA on November 2, 1920, as the first commercially licensed radio station in America; the commercial broadcasting designation came from the type of broadcast license. The first licensed broadcast in the United States came from KDKA itself: the results of the Harding/Cox Presidential Election; the Montreal station that became CFCF began broadcast programming on May 20, 1920, the Detroit station that became WWJ began program broadcasts beginning on August 20, 1920, although neither held a license at the time. In 1920, wireless broadcasts for entertainment began in the UK from the Marconi Research Centre 2MT at Writtle near Chelmsford, England. A famous broadcast from Marconi's New Street Works factory in Chelmsford was made by the famous soprano Dame Nellie Melba on 15 June 1920, where she sang two arias and her famous trill.
She was the first artist of international renown to participate in direct radio broadcasts. The 2MT station began to broadcast regular entertainment in 1922; the BBC was amalgamated in 1922 and received a Royal Charter in 1926, making it the first national broadcaster in the world, followed by Czech Radio and other European broadcasters in 1923. Radio Argentina began scheduled transmissions from the Teatro Coliseo in Buenos Aires on August 27, 1920, making its own priority claim; the station got its license on November 19, 1923. The delay was due to the lack of official Argentine licensing procedures before that date; this station continued regular broadcasting of entertainment and cultural fare for several decades. Radio in education soon followed and colleges across the U. S. began adding radio broadcasting courses to their curricula. Curry College in Milton, Massachusetts introduced one of the first broadcasting majors in 1932 when the college teamed up with WLOE in Boston to have students broadcast programs.
Broadcasting service is – according to Article 1.38 of the International Telecommunication Union´s Radio Regulations – defined as «A radiocommunication service in which the transmission are intended for direct reception by the general public. This service may include sound transmissions, television transmissions or other types of transmission.» Definitions identical to those contained in the Annexes to the Constitution and Convention of the International Telecommunication Union are marked "" or "" respectively. A radio broadcasting station is associated with wireless transmission, though in practice broadcasting transmission take place using both wires and radio waves; the point of this is that anyone with the appropriate receiving technology can receive the broadcast. In line to ITU Radio Regulations each broadcasting station shall be classified by the service in which it operates permanently or temporarily. Broadcasting by radio takes several forms; these include FM stations. There are several subtypes, namely commercial broadcasting, non-commercial educational public broadcasting and non-profit varieties as well as community radio, student-run campus radio stations, and
Charleston, South Carolina
Charleston is the oldest and largest city in the U. S. state of South Carolina, the county seat of Charleston County, the principal city in the Charleston–North Charleston–Summerville Metropolitan Statistical Area. The city lies just south of the geographical midpoint of South Carolina's coastline and is located on Charleston Harbor, an inlet of the Atlantic Ocean formed by the confluence of the Ashley and Wando rivers. Charleston had an estimated population of 134,875 in 2017; the estimated population of the Charleston metropolitan area, comprising Berkeley and Dorchester counties, was 761,155 residents in 2016, the third-largest in the state and the 78th-largest metropolitan statistical area in the United States. Charleston was founded in 1670 as Charles Town, its initial location at Albemarle Point on the west bank of the Ashley River was abandoned in 1680 for its present site, which became the fifth-largest city in North America within ten years. Despite its size, it remained unincorporated throughout the colonial period.
Election districts were organized according to Anglican parishes, some social services were managed by Anglican wardens and vestries. Charleston adopted its present spelling with its incorporation as a city in 1783 at the close of the Revolutionary War. Population growth in the interior of South Carolina influenced the removal of the state government to Columbia in 1788, but the port city remained among the ten largest cities in the United States through the 1840 census. Historians estimate that "nearly half of all Africans brought to America arrived in Charleston", most at Gadsden's Wharf; the only major antebellum American city to have a majority-enslaved population, Charleston was controlled by an oligarchy of white planters and merchants who forced the federal government to revise its 1828 and 1832 tariffs during the Nullification Crisis and launched the Civil War in 1861 by seizing the Arsenal, Castle Pinckney, Fort Sumter from their federal garrisons. Known for its rich history, well-preserved architecture, distinguished restaurants, hospitable people, Charleston is a popular tourist destination.
It has received numerous accolades, including "America's Most Friendly " by Travel + Leisure in 2011 and in 2013 and 2014 by Condé Nast Traveler, "the most polite and hospitable city in America" by Southern Living magazine. In 2016, Charleston was ranked the "World's Best City" by Travel + Leisure; the city proper consists of six distinct districts. Downtown, or sometimes referred to as The Peninsula, is Charleston's center city separated by the Ashley River to the west and the Cooper River to the east. West Ashley, residential area to the west of Downtown bordered by the Ashley River to the east and the Stono River to the west. Johns Island, far western limits of Charleston home to the Angel Oak, bordered by the Stono River to the east, Kiawah River to the south and Wadmalaw Island to the west. James Island, popular residential area between Downtown and the town of Folly Beach where the McLeod Plantation is located. Cainhoy Peninsula, far eastern limits of Charleston bordered by the Wando River to the west and Nowell Creek to the east.
Daniel Island, fast-growing residential area to the north of downtown, east of the Cooper River and west of the Wando River. The incorporated city fit into 4–5 square miles as late as the First World War, but has since expanded, crossing the Ashley River and encompassing James Island and some of Johns Island; the city limits have expanded across the Cooper River, encompassing Daniel Island and the Cainhoy area. The present city has a total area of 127.5 square miles, of which 109.0 square miles is land and 18.5 square miles is covered by water. North Charleston blocks any expansion up the peninsula, Mount Pleasant occupies the land directly east of the Cooper River. Charleston Harbor runs about 7 miles southeast to the Atlantic with an average width of about 2 miles, surrounded on all sides except its entrance. Sullivan's Island lies to the north of Morris Island to the south; the entrance itself is about 1 mile wide. The tidal rivers are evidence of drowned coastline. There is a submerged river delta off the mouth of the harbor and the Cooper River is deep.
Charleston has a humid subtropical climate, with mild winters, hot humid summers, significant rainfall all year long. Summer is the wettest season. Fall remains warm through the middle of November. Winter is short and mild, is characterized by occasional rain. Measurable snow only occurs several times per decade at the most however freezing rain is more common. However, 6.0 in fell at the airport on December 23, 1989, the largest single-day fall on record, contributing to a single-storm and seasonal record of 8.0 in snowfall. The highest temperature recorded within city limits was 104 °F on June 2, 1985, June 24, 1944, the lowest was 7 °F on February 14, 1899. At the airport, where official records are kept, the historical range is 105 °F on August 1, 1999, down to 6 °F on January 21, 1985. Hurricanes are a major threat to the area during the summer and early fall, with several severe hurrican
Manning, South Carolina
Manning is a city in and the county seat of Clarendon County, South Carolina, United States. The population was 4,108 as of the 2010 census, with an estimated population in 2014 of 4,059, it was named after former South Carolina governor John Laurence Manning. In 1855, the South Carolina Legislature appointed a group of commissioners to select and purchase a tract of land for "the Village of Manning" in the newly formed Clarendon County. According to the Watchmen, a local newspaper of the time, "the Legislature granted a bill of divorce between Clarendon and Claremont." Thirteen men were named as commissioners to select and acquire from 6 to 60 acres on which to lay out the new courthouse village: R. C. Baker, L. F. Rhame, J. C. Brock, W. W. Owens, Joseph Sprott, J. C. Burgess, M. T. Brogdon, J. J. Nelson, Samuel A. Burgess, J. J. McFadden, Jesse Hill, R. R. Haynsworth, P. S. Worsham. Five other commissioners, R. I. Manning, L. F. Rhame, J. B. Brogdon, J. J. Conyers, William A. Burgess, were named when it came time to erect the courthouse and jail from a state appropriation of $18,000, plus whatever funds might be realized from the sale of lots.
The site for the village was presented to the state by Captain Joseph Copley Burgess, the Plat of Manning was prepared and filed in Sumter County Courthouse. On the second Monday of the following October, the new district officers were elected, Clarendon began to operate independently from Sumter District with Manning as its county seat; the city was named for John Lawrence Manning, elected to both chambers in the General Assembly. He was chosen by the Assembly to serve as Governor of South Carolina from 1852 to 1854. George Allen Huggins was the first intendant of Manning. Manning's Post Office was established in 1856, Thomas S. Coogler was appointed as the first Postmaster. Manning's first library, the Hannah Levi Memorial Library, was completed in 1910, it was funded by the children of Moses and Hannah Levi, by the sale of the Moses Levi Institute. They named it in honor of their mother, it became known as the Manning Library and was the only public library in the county. It became a county library in 1976 and continued to operate until the opening of the Harvin Clarendon County Library in 1984.
The building now houses the Clarendon County Archives and History Center. Manning was damaged several times over its history. A large portion of the original town, including the courthouse, was destroyed in the Civil War in 1865 during what is known as "Potter's Raid"; this raid by Union troops took place only a few days before Gen. Robert E. Lee's surrender at Appomattox. Manning was struck by a downtown fire in 1895 and damaged by a tornado in 1915. Railroads, abundant timber and diverse agriculture allowed Manning to flourish during the late 19th century and into the 20th century. In 1933, Highway 4 was changed to U. S. Route 301 and thanks in part to the efforts of Manning resident W. P. Legg and Clarendon County became a preferred route of the Washington to Florida motorist. Manning is along the I-95 corridor and attracts retirees looking for various recreational activities and mild climates; as early as 1960 Manning was one of many towns across the South for the staging of peaceful Civil Rights demonstrations and sit-ins.
Unlike in some other areas, the demonstrations in Manning occurred without significant incident, but helped belie the local media's message that black Carolinians accepted the status quo. Manning and the surrounding region was still adjusting to the decisions handed down in the Briggs v. Elliott and Brown v. Board of Education rulings against racial segregation in schools. In 1969 Pansy Ridgeway became the first woman to be elected mayor of Manning, she served as mayor of Manning from 1970–96 and was the third woman elected mayor in South Carolina and the first woman elected president of the South Carolina Municipal Association. The city government consists of a city council; the mayor is elected at-large, the council consists of six members who are elected from each of six districts. Manning is represented in the South Carolina Senate by John C. Land III, born in Manning, it is part of South Carolina's 6th congressional district which since January 1993 has been represented by Jim Clyburn. Manning is home to The Manning Times newspaper.
It is updated online daily. Manning is home to Manning High School and Laurence Manning Academy, it is the location of the F. E. DuBose Campus of Central Carolina Technical College, it is home to the Manning Junior High School, Manning Elementary School, Manning Early Childhood Center. Manning is located near the center of Clarendon County at 33°41′38″N 80°12′55″W, it is just to the east of Interstate 95 and at the intersection of U. S. 301 and U. S. 521. Via I-95 it is 48 miles northeast to Florence and 35 miles southwest to Interstate 26. US 301 leads northeast 18 miles to Turbeville and southwest 10 miles to Summerton, while US 521 leads northwest 19 miles to Sumter and southeast 15 miles to Greeleyville. According to the United States Census Bureau, Manning has a total area of 2.76 square miles, all land. It is just south of the Pocotaligo River, a tributary of the Black River; as of the census of 2000, there were 4,025 people, 1,550 households, 1,063 families residing in the city. The population density was 1,671.1 people per square mile.
There were 1,727 housing units at an average density of 717.0 per square mile. The racial makeup of the city was 62.36% African American, 35.80% White, 0.62% Asian, 0.25% Native
Frequency is the number of occurrences of a repeating event per unit of time. It is referred to as temporal frequency, which emphasizes the contrast to spatial frequency and angular frequency; the period is the duration of time of one cycle in a repeating event, so the period is the reciprocal of the frequency. For example: if a newborn baby's heart beats at a frequency of 120 times a minute, its period—the time interval between beats—is half a second. Frequency is an important parameter used in science and engineering to specify the rate of oscillatory and vibratory phenomena, such as mechanical vibrations, audio signals, radio waves, light. For cyclical processes, such as rotation, oscillations, or waves, frequency is defined as a number of cycles per unit time. In physics and engineering disciplines, such as optics and radio, frequency is denoted by a Latin letter f or by the Greek letter ν or ν; the relation between the frequency and the period T of a repeating event or oscillation is given by f = 1 T.
The SI derived unit of frequency is the hertz, named after the German physicist Heinrich Hertz. One hertz means. If a TV has a refresh rate of 1 hertz the TV's screen will change its picture once a second. A previous name for this unit was cycles per second; the SI unit for period is the second. A traditional unit of measure used with rotating mechanical devices is revolutions per minute, abbreviated r/min or rpm. 60 rpm equals one hertz. As a matter of convenience and slower waves, such as ocean surface waves, tend to be described by wave period rather than frequency. Short and fast waves, like audio and radio, are described by their frequency instead of period; these used conversions are listed below: Angular frequency denoted by the Greek letter ω, is defined as the rate of change of angular displacement, θ, or the rate of change of the phase of a sinusoidal waveform, or as the rate of change of the argument to the sine function: y = sin = sin = sin d θ d t = ω = 2 π f Angular frequency is measured in radians per second but, for discrete-time signals, can be expressed as radians per sampling interval, a dimensionless quantity.
Angular frequency is larger than regular frequency by a factor of 2π. Spatial frequency is analogous to temporal frequency, but the time axis is replaced by one or more spatial displacement axes. E.g.: y = sin = sin d θ d x = k Wavenumber, k, is the spatial frequency analogue of angular temporal frequency and is measured in radians per meter. In the case of more than one spatial dimension, wavenumber is a vector quantity. For periodic waves in nondispersive media, frequency has an inverse relationship to the wavelength, λ. In dispersive media, the frequency f of a sinusoidal wave is equal to the phase velocity v of the wave divided by the wavelength λ of the wave: f = v λ. In the special case of electromagnetic waves moving through a vacuum v = c, where c is the speed of light in a vacuum, this expression becomes: f = c λ; when waves from a monochrome source travel from one medium to another, their frequency remains the same—only their wavelength and speed change. Measurement of frequency can done in the following ways, Calculating the frequency of a repeating event is accomplished by counting the number of times that event occurs within a specific time period dividing the count by the length of the time period.
For example, if 71 events occur within 15 seconds the frequency is: f = 71 15 s ≈ 4.73 Hz If the number of counts is not large, it is more accurate to measure the time interval for a predetermined number of occurrences, rather than the number of occurrences within a specified time. The latter method introduces a random error into the count of between zero and one count, so on average half a count; this is called gating error and causes an average error in the calculated frequency of Δ f = 1 2 T
Adult contemporary music
In North American music, adult contemporary music is a form of radio-played popular music, ranging from 1960s vocal and 1970s soft rock music to predominantly ballad-heavy music of the present day, with varying degrees of easy listening, soul and blues, quiet storm, rock influence. Adult contemporary is rather a continuation of the easy listening and soft rock style that became popular in the 1960s and 1970s with some adjustments that reflect the evolution of pop/rock music. Adult contemporary tends to have lush and polished qualities where emphasis on melody and harmonies is accentuated, it is melodic enough to get a listener's attention, is inoffensive and pleasurable enough to work well as background music. Like most of pop music, its songs tend to be written in a basic format employing a verse–chorus structure; the format is heavy on romantic sentimental ballads which use acoustic instruments such as acoustic guitars, pianos and sometimes an orchestral set. The electric guitars are faint and high-pitched.
However, recent adult contemporary music may feature synthesizers. An AC radio station may play mainstream music, but it excludes hip hop, dance tracks, hard rock, some forms of teen pop, as these are less popular among adults, the target demographic. AC radio targets the 25–44 age group, the demographic that has received the most attention from advertisers since the 1960s. A common practice in recent years of adult contemporary stations is to play less newer music and more hits of the past; this de-emphasis on new songs slows the progression of the AC chart. Over the years, AC has spawned subgenres including "hot AC", "soft AC", "urban AC", "rhythmic AC", "Christian AC"; some stations play only "hot AC", only one of the variety of subgenres. Therefore, it is not considered a specific genre of music. Adult contemporary traces its roots to the 1960s easy listening format, which adopted a 70—80% instrumental to 20–30% vocal mix. A few offered 90% instrumentals, a handful were instrumental; the easy listening format, as it was first known, was born of a desire by some radio stations in the late 1950s and early 1960s to continue playing current hit songs but distinguish themselves from being branded as "rock and roll" stations.
Billboard first published the Easy Listening chart July 1961, with 20 songs. The chart described itself as "not too far out in either direction"; the vocalists consisted of artists such as Frank Sinatra, Doris Day, Johnny Mathis, Connie Francis, Nat King Cole, Perry Como, others. The custom recordings were instrumental versions of current or recent rock and roll or pop hit songs, a move intended to give the stations more mass appeal without selling out; some stations would occasionally play earlier big band-era recordings from the 1940s and early 1950s. After 1965, differences between the Hot 100 chart and the Easy Listening chart became more pronounced. Better reflecting what middle of the road stations were playing, the composition of the chart changed dramatically; as rock music continued to harden, there was much less crossover between the Hot 100 and Easy Listening chart than there had been in the early half of the 1960s. Roger Miller, Barbra Streisand and Bobby Vinton were among the chart's most popular performers.
One big impetus for the development of the AC radio format was that, when rock and roll music first became popular in the mid-1950s, many more conservative radio stations wanted to continue to play current hit songs while shying away from rock. These middle of the road stations frequently included older, pre-rock-era adult standards and big band titles to further appeal to adult listeners who had grown up with those songs. Another big impetus for the evolution of the AC radio format was the popularity of easy listening or "beautiful music" stations, stations with music designed to be purely ambient. Whereas most easy listening music was instrumental, created by unknown artists, purchased, AC was an attempt to create a similar "lite" format by choosing certain tracks of popular artists. Hard rock had been established as a mainstream genre by 1965. From the end of the 1960s, it became common to divide mainstream rock music into soft and hard rock, with both emerging as major radio formats in the US.
Soft rock was derived from folk rock, using acoustic instruments and putting more emphasis on melody and harmonies. Major artists included Carole King, Cat Stevens, James Taylor and Bread; the Hot 100 and Easy Listening charts became more similar again toward the end of the 1960s and into the early and mid-1970s, when the texture of much of the music played on Top 40 radio once more began to soften. The adult contemporary format began evolving into the sound that defined it, with rock-oriented acts as Chicago, the Eagles, Elton John becoming associated with the format. Soft rock reached its commercial peak in the mid-to-late 1970s with acts such as Toto, England Dan & John Ford Coley, Air Supply and Crofts, Dan Fogelberg and the reformed Fleetwood Mac, whose Rumours was the best-selling album of the decade. By 1977, some radio stations, notably New York's WTFM and NBC-owned WYNY, Boston's WEEI, had switched to an all-soft rock format; as Softrock
Alternative rock is a style of rock music that emerged from the independent music underground of the 1980s and became popular in the 1990s. In this instance, the word "alternative" refers to the genre's distinction from mainstream rock music; the term's original meaning was broader, referring to a generation of musicians unified by their collective debt to either the musical style or the independent, DIY ethos of punk rock, which in the late 1970s laid the groundwork for alternative music. At times, "alternative" has been used as a catch-all description for music from underground rock artists that receives mainstream recognition, or for any music, whether rock or not, seen to be descended from punk rock. Alternative rock broadly consists of music that differs in terms of its sound, social context and regional roots. By the end of the 1980s, magazines and zines, college radio airplay, word of mouth had increased the prominence and highlighted the diversity of alternative rock, helping to define a number of distinct styles such as noise pop, indie rock and shoegaze.
Most of these subgenres had achieved minor mainstream notice and a few bands representing them, such as Hüsker Dü and R. E. M. had signed to major labels. But most alternative bands' commercial success was limited in comparison to other genres of rock and pop music at the time, most acts remained signed to independent labels and received little attention from mainstream radio, television, or newspapers. With the breakthrough of Nirvana and the popularity of the grunge and Britpop movements in the 1990s, alternative rock entered the musical mainstream and many alternative bands became successful. In the past, popular music tastes were dictated by music executives within large entertainment corporations. Record companies signed contracts with those entertainers who were thought to become the most popular, therefore who could generate the most sales; these bands were able to record their songs in expensive studios, their works sold through record store chains that were owned by the entertainment corporations.
The record companies worked with radio and television companies to get the most exposure for their artists. The people making the decisions were business people dealing with music as a product, those bands who were not making the expected sales figures were excluded from this system. Before the term alternative rock came into common usage around 1990, the sort of music to which it refers was known by a variety of terms. In 1979, Terry Tolkin used the term Alternative Music to describe the groups. In 1979 Dallas radio station KZEW had a late night new wave show entitled "Rock and Roll Alternative". "College rock" was used in the United States to describe the music during the 1980s due to its links to the college radio circuit and the tastes of college students. In the United Kingdom, dozens of small do it yourself record labels emerged as a result of the punk subculture. According to the founder of one of these labels, Cherry Red, NME and Sounds magazines published charts based on small record stores called "Alternative Charts".
The first national chart based on distribution called the Indie Chart was published in January 1980. At the time, the term indie was used to describe independently distributed records. By 1985, indie' had come to mean a particular genre, or group of subgenres, rather than distribution status; the use of the term alternative to describe rock music originated around the mid-1980s. Individuals who worked as DJs and promoters during the 1980s claim the term originates from American FM radio of the 1970s, which served as a progressive alternative to top 40 radio formats by featuring longer songs and giving DJs more freedom in song selection. According to one former DJ and promoter, "Somehow this term'alternative' got rediscovered and heisted by college radio people during the 80s who applied it to new post-punk, indie, or underground-whatever music". At first the term referred to intentionally non–mainstream rock acts that were not influenced by "heavy metal ballads, rarefied new wave" and "high-energy dance anthems".
Usage of the term would broaden to include new wave, punk rock, post-punk, "college"/"indie" rock, all found on the American "commercial alternative" radio stations of the time such as Los Angeles' KROQ-FM. Journalist Jim Gerr wrote that Alternative encompassed variants such as "rap, trash and industrial". In December 1991, Spin magazine noted: "this year, for the first time, it became resoundingly clear that what has been considered alternative rock – a college-centered marketing group with lucrative, if limited, potential- has in fact moved into the mainstream"; the bill of the first Lollapalooza, an itinerant festival in North America conceived by Jane's Addiction frontman Perry Farrell, reunited "disparate elements of the alternative rock community" including Henry Rollins, Butthole Surfers, Ice-T, Nine Inch Nails and the Banshees and Jane's Addiction. That same year, Farrell coined the term Alternative Nation. In the late 1990s, the definition again became more specific. In 1997, Neil Strauss of The New York Times defined alternative rock as "hard-edged rock distinguished by brittle,'70s-inspired guitar riffing and singers agonizing over their problems until they take on epic proportions".
Defining music as alt
AM broadcasting is a radio broadcasting technology, which employs amplitude modulation transmissions. It was the first method developed for making audio radio transmissions, is still used worldwide for medium wave transmissions, but on the longwave and shortwave radio bands; 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, a period called the "Golden Age of Radio", until television broadcasting became widespread in the 1950s and received most of the programming carried by radio. Subsequently, AM radio's audiences have greatly shrunk due to competition from FM radio, Digital Audio Broadcasting, satellite radio, HD radio and Internet streaming. AM transmissions are much more susceptible than FM or digital signals are to interference, have lower audio fidelity.
Thus, AM broadcasters tend to specialise in spoken-word formats, such as talk radio, all news and sports, leaving the broadcasting of music to FM and digital stations. The idea of broadcasting — the unrestricted transmission of signals to a widespread audience — dates back to the founding period of radio development though the earliest radio transmissions 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. Lodge 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 The Electrician 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 a short-range "wireless telephone" demonstration, that included broadcasting speech and music to seven locations throughout Murray, Kentucky.
However, this was transmitted using induction rather than radio signals, 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", "a single message can be sent from 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 the United States and France this led to a small market of receiver lines designed geared for jewelers who needed accurate time to set their clocks, including the Ondophone in France, 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 attracted the interest of amateur radio enthusiasts.
It was 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 been used for distributing entertainment, outside of a few "telephone newspaper" systems, most of which were established in Europe. 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 credited as 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" signals, which could be "modulated" to reflect the sounds being transmitted. Fessenden's basic approach was disclosed in U. S. Patent 706,737, which he applied for on May 29, 1901, was issued the next year, it called for the use of a high-speed alternator that generated "pure sine waves" and produced "a continuous train of radiant waves of uniform strength", or, in modern terminology, a continuous-wave 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 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 reported that, in the fall of 1900, he transmitted speech over a distance of about 1.6 kilometers, 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 sophist