FM broadcasting is a method of radio broadcasting using frequency modulation technology. Invented in 1933 by American engineer Edwin Armstrong, wide-band FM is used worldwide to provide high-fidelity sound over broadcast radio. FM broadcasting is capable of better sound quality than AM broadcasting, the chief competing radio broadcasting technology, so it is used for most music broadcasts. Theoretically wideband AM can offer good sound quality, provided the reception conditions are ideal. FM radio stations use the VHF frequencies; the term "FM band" describes the frequency band in a given country, dedicated to FM broadcasting. Throughout the world, the FM broadcast band falls within the VHF part of the radio spectrum. 87.5 to 108.0 MHz is used, or some portion thereof, with few exceptions: In the former Soviet republics, some former Eastern Bloc countries, the older 65.8–74 MHz band is used. Assigned frequencies are at intervals of 30 kHz; this band, sometimes referred to as the OIRT band, is being phased out in many countries.
In those countries the 87.5–108.0 MHz band is referred to as the CCIR band. In Japan, the band 76–95 MHz is used; the frequency of an FM broadcast station is an exact multiple of 100 kHz. In most of South Korea, the Americas, the Philippines and the Caribbean, only odd multiples are used. In some parts of Europe and Africa, only multiples are used. In the UK odd or are used. In Italy, multiples of 50 kHz are used. In most countries the maximum permitted frequency error is specified, the unmodulated carrier should be within 2000 Hz of the assigned frequency. There are other unusual and obsolete FM broadcasting standards in some countries, including 1, 10, 30, 74, 500, 300 kHz. However, to minimise inter-channel interference, stations operating from the same or geographically close transmitter sites tend to keep to at least a 500 kHz frequency separation when closer frequency spacing is technically permitted, with closer tunings reserved for more distantly spaced transmitters, as interfering signals are more attenuated and so have less effect on neighboring frequencies.
Frequency modulation or FM is a form of modulation which conveys information by varying the frequency of a carrier wave. With FM, frequency deviation from the assigned carrier frequency at any instant is directly proportional to the amplitude of the input signal, determining the instantaneous frequency of the transmitted signal; because transmitted FM signals use more bandwidth than AM signals, this form of modulation is used with the higher frequencies used by TV, the FM broadcast band, land mobile radio systems. The maximum frequency deviation of the carrier is specified and regulated by the licensing authorities in each country. For a stereo broadcast, the maximum permitted carrier deviation is invariably ±75 kHz, although a little higher is permitted in the United States when SCA systems are used. For a monophonic broadcast, again the most common permitted. However, some countries specify a lower value for monophonic broadcasts, such as ±50 kHz. Random noise has a triangular spectral distribution in an FM system, with the effect that noise occurs predominantly at the highest audio frequencies within the baseband.
This can be offset, to a limited extent, by boosting the high frequencies before transmission and reducing them by a corresponding amount in the receiver. Reducing the high audio frequencies in the receiver reduces the high-frequency noise; these processes of boosting and reducing certain frequencies are known as pre-emphasis and de-emphasis, respectively. The amount of pre-emphasis and de-emphasis used is defined by the time constant of a simple RC filter circuit. In most of the world a 50 µs time constant is used. In the Americas and South Korea, 75 µs is used; this applies to both stereo transmissions. For stereo, pre-emphasis is applied to the left and right channels before multiplexing; the use of pre-emphasis becomes a problem because of the fact that many forms of contemporary music contain more high-frequency energy than the musical styles which prevailed at the birth of FM broadcasting. Pre-emphasizing these high frequency sounds would cause excessive deviation of the FM carrier. Modulation control devices are used to prevent this.
Systems more modern than FM broadcasting tend to use either programme-dependent variable pre-emphasis. Long before FM stereo transmission was considered, FM multiplexing of other types of audio level information was experimented with. Edwin Armstrong who invented FM was the first to experiment with multiplexing, at his experimental 41 MHz station W2XDG located on the 85th floor of the Empire State Building in New York City; these FM multiplex transmissions started in November 1934 and consisted of the main channel audio program and three subcarriers: a fax program, a synchronizing signal for the fax program and a telegraph “order” channel. These original FM multiplex subcarriers were amplitude modulated. Two musical programs, consisting of both the Red and Blue Network program feeds of the NBC Radio Network, were transmitted using the same system of subcarrier modulation as part of a studio-to-transmitter link system. In April 1935, the AM subcarriers were replaced with much improved results.
The first FM subcarrier transmissions emanating from Major Armstrong's experimental station KE2XCC at Alpine, New Jersey occurred in 1948. These transmissions consisted of two-cha
Christmas is an annual festival, commemorating the birth of Jesus Christ, observed on December 25 as a religious and cultural celebration among billions of people around the world. A feast central to the Christian liturgical year, it is preceded by the season of Advent or the Nativity Fast and initiates the season of Christmastide, which in the West lasts twelve days and culminates on Twelfth Night. Christmas Day is a public holiday in many of the world's nations, is celebrated religiously by a majority of Christians, as well as culturally by many non-Christians, forms an integral part of the holiday season centered around it; the traditional Christmas narrative, the Nativity of Jesus, delineated in the New Testament says that Jesus was born in Bethlehem, in accordance with messianic prophecies. When Joseph and Mary arrived in the city, the inn had no room and so they were offered a stable where the Christ Child was soon born, with angels proclaiming this news to shepherds who further disseminated the information.
Although the month and date of Jesus' birth are unknown, the church in the early fourth century fixed the date as December 25. This corresponds to the date of the solstice on the Roman calendar. Most Christians celebrate on December 25 in the Gregorian calendar, adopted universally in the civil calendars used in countries throughout the world. However, some Eastern Christian Churches celebrate Christmas on December 25 of the older Julian calendar, which corresponds to a January date in the Gregorian calendar. For Christians, the belief that God came into the world in the form of man to atone for the sins of humanity, rather than the exact birth date, is considered to be the primary purpose in celebrating Christmas; the celebratory customs associated in various countries with Christmas have a mix of pre-Christian and secular themes and origins. Popular modern customs of the holiday include gift giving, completing an Advent calendar or Advent wreath, Christmas music and caroling, lighting a Christingle, viewing a Nativity play, an exchange of Christmas cards, church services, a special meal, pulling Christmas crackers and the display of various Christmas decorations, including Christmas trees, Christmas lights, nativity scenes, wreaths and holly.
In addition, several related and interchangeable figures, known as Santa Claus, Father Christmas, Saint Nicholas, Christkind, are associated with bringing gifts to children during the Christmas season and have their own body of traditions and lore. Because gift-giving and many other aspects of the Christmas festival involve heightened economic activity, the holiday has become a significant event and a key sales period for retailers and businesses; the economic impact of Christmas has grown over the past few centuries in many regions of the world. "Christmas" is a shortened form of "Christ's mass". The word is recorded as Crīstesmæsse in 1038 and Cristes-messe in 1131. Crīst is from Greek Khrīstos, a translation of Hebrew Māšîaḥ, "Messiah", meaning "anointed"; the form Christenmas was historically used, but is now considered archaic and dialectal. Xmas is an abbreviation of Christmas found in print, based on the initial letter chi in Greek Khrīstos, "Christ", though numerous style guides discourage its use.
In addition to "Christmas", the holiday has been known by various other names throughout its history. The Anglo-Saxons referred to the feast as "midwinter", or, more as Nātiuiteð. "Nativity", meaning "birth", is from Latin nātīvitās. In Old English, Gēola referred to the period corresponding to December and January, equated with Christian Christmas. "Noel" entered English in the late 14th century and is from the Old French noël or naël, itself from the Latin nātālis meaning "birth". The gospels of Luke and Matthew describe Jesus as being born in Bethlehem to the Virgin Mary. In Luke and Mary travel from Nazareth to Bethlehem for the census, Jesus is born there and laid in a manger. Angels proclaimed him a savior for all people, shepherds came to adore him. Matthew adds that the magi follow a star to Bethlehem to bring gifts to Jesus, born the king of the Jews. King Herod orders the massacre of all the boys less than two years old in Bethlehem, but the family flees to Egypt and returns to Nazareth.
The nativity stories recounted in Matthew and Luke prompted early Christian writers to suggest various dates for the anniversary. Although no date is indicated in the gospels, early Christians connected Jesus to the Sun through the use of such phrases as "Sun of righteousness." The Romans marked the winter solstice on December 25. The first recorded Christmas celebration was in Rome on December 25, 336. Christmas played a role in the Arian controversy of the fourth century. After this controversy was played out, the prominence of the holiday declined; the feast regained prominence after 800. Associating it with drunkenness and other misbehavior, the Puritans banned Christmas during the Reformation, it remained disreputable. In the early 19th century, Christmas was reconceived by Washington Irving, Charles Dickens, other authors as a holiday emphasizing family, kind-heartedness, gift-giving, Santa Claus. Christmas does not appear on th
Bethany is a city in Oklahoma County, United States, a part of the Oklahoma City metropolitan area. The community was founded in 1909 by followers of the Church of the Nazarene from Oklahoma City. Bethany was founded July 28, 1909 as a community where members of the Church of the Nazarene could express their religious beliefs without interference by non-members; the town was named after the biblical place of Bethany. The community established the Oklahoma Holiness College. Two other institutions were soon established, the Oklahoma Orphanage operated by Mattie Mallory, the Nazarene Rescue Home for unwed mothers. Bethany incorporated on August 8, 1910 as a rural town whose economy depended on the surrounding farmlands, it gained a post office on March 11, 1913. The large population of Nazarenes soon caused the town to enact strict blue laws that banned alcohol, gambling, movies and working on Sundays; the blue laws have been relaxed since Bethany reorganized as a first class city in 1931. An F4 tornado nearly wiped out Bethany on November 19, 1930, killing 23 people and destroying 652 buildings.
It is one of only three documented violent November tornadoes in Oklahoma since 1900. Recovery from the storm was slow until the outbreak of World War II, when the city began developing as a bedroom community for Oklahoma City. Bethany is located at 35°30′17″N 97°38′20″W; the city is in the central part of Oklahoma County, about 10 miles west of downtown Oklahoma City, is bounded by Warr Acres on the east and by Lake Overholser and Stinchcomb Wildlife Refuge on the west. According to the United States Census Bureau, the city has a total area of 5.2 square miles, all land. As of the census of 2000, there were 20,307 people, 8,161 households, 5,280 families residing in the city; the population density was 3,896.7 people per square mile. There were 8,874 housing units at an average density of 1,702.8 per square mile. The racial makeup of the city was 85.79% White, 4.36% African American, 2.87% Native American, 1.38% Asian, 0.05% Pacific Islander, 2.18% from other races, 3.36% from two or more races.
Hispanic or Latino of any race were 5.80% of the population. There were 8,161 households out of which 28.1% had children under the age of 18 living with them, 49.0% were married couples living together, 12.1% had a female householder with no husband present, 35.3% were non-families. 31.0% of all households were made up of individuals and 12.2% had someone living alone, 65 years of age or older. The average household size was 2.33 and the average family size was 2.91. In the city, the population was spread out with 23.0% under the age of 18, 12.9% from 18 to 24, 25.8% from 25 to 44, 21.5% from 45 to 64, 16.7% who were 65 years of age or older. The median age was 36 years. For every 100 females, there were 89.7 males. For every 100 females age 18 and over, there were 84.4 males. The median income for a household in the city was $35,073, the median income for a family was $43,905. Males had a median income of $30,180 versus $24,747 for females; the per capita income for the city was $17,793. About 6.9% of families and 9.0% of the population were below the poverty line, including 12.7% of those under age 18 and 3.9% of those age 65 or over.
The city operates using a council-manager government system. The city council comprises two members elected from each of the four wards; the city manager, city attorney, municipal judge are appointed by the council. The mayor is elected at large; the current Mayor is KP Westmoreland. Bethany was represented in the Oklahoma Senate by David Holt until his election as Mayor of Oklahoma City in 2018, it is represented in the Oklahoma House of Representatives by Tammy West. The largest employers in the area include: Southern Nazarene University, Southwestern Christian University, The Children's Center and Putnam City Public Schools, City of Bethany, Gilbert Medical Clinic. Bethany became the headquarters for the International Pentecostal Holiness Church in 1975, it is the headquarters for the Pinto Horse Association of America. Wiley Post Airport handles business and commercial aircraft, it has an industrial park that contains about fifty aviation-related businesses, including Rockwell International, Million Air, Servicenter Incorporated, the Federal Aviation Administration Systems Management Office.
The main vehicular route in and out of Bethany is the 39th Street Expressway, which runs through downtown Bethany. Both Bethany School District and the Putnam City School District provide educational needs to citizens within its district borders; the chief educational providers for elementary-aged students include the Southern Nazarene University School for Children on the campus of Calvary Church of the Nazarene, about 1 mile south of Southern Nazarene University, as well as Bethany Earl Harris Elementary. Primary school goes from pre-K - 5th grade. Bethany Middle School and Western Oaks Junior High School respond to those in 6th - 8th grade. Bethany High School, home of the Bronchos, covers grades 9th - 12th. Putnam City schools located within Bethany include: Apollo Elementary, Lake Park Elementary, Overholser Elementary, Western Oaks Elementary, Western Oaks Middle School; the superintendent for Bethany Public Schools is Drew Eichelberger. The website for Bethany Public Schools is http://bethanyschools.com/.
The superintendent for Putnam City Schools is Dr. Fred Rhodes; the website for Putnam City Schools is http://putnamcityschools.org/. Bethany is home to two universities. Southern Nazarene University and Southwestern Christian University
Height above average terrain
Height above average terrain, or effective height above average terrain, is a measure of how high an antenna site is above the surrounding landscape. HAAT is used extensively in FM radio and television, as it is more important than effective radiated power in determining the range of broadcasts. For international coordination, it is measured in meters by the Federal Communications Commission in the United States, as Canada and Mexico have extensive border zones where stations can be received on either side of the international boundaries. Stations that want to increase above a certain HAAT must reduce their power accordingly, based on the maximum distance their station class is allowed to cover; the FCC procedure to calculate HAAT is: from the proposed or actual antenna site, either 12 or 16 radials were drawn, points at 2, 4, 6, 8, 10 miles radius along each radial were used. The entire radial graph could be rotated to achieve the best effect for the station; the altitude of the antenna site, minus the average altitude of all the specified points, is the HAAT.
This can create some unusual cases in mountainous regions—it is possible to have a negative number for HAAT. The FCC has divided the Contiguous United States into three zones for the determination of spacing between FM and TV stations using the same frequencies. FM and TV stations are assigned maximum ERP and HAAT values, depending on their assigned zones, to prevent co-channel interference; the FCC regulations for ERP and HAAT are listed under Title 47, Part 73 of the Code of Federal Regulations. Maximum HAAT: 150 metres Maximum ERP: 50 kilowatts Minimum co-channel separation: 241 km Maximum HAAT: 600 metres Maximum ERP: 100 kilowatts Minimum co-channel separation: 290 km. In all zones, maximum ERP for analog TV transmitters is. In addition, Zone I-A consists of all of California south of 40° north latitude, Puerto Rico and the U. S. Virgin Islands. Zones I and I-A have the most "grandfathered" overpowered stations, which are allowed the same extended coverage areas that they had before the zones were established.
One of the most powerful of these stations is WBCT in Grand Rapids, which operates at 320,000 watts and 238 meters HAAT. Zone III consists of all of Florida and the areas of Alabama, Louisiana and Texas within 241.4 kilometers of the Gulf of Mexico. Zone II is all the rest of the Continental United States and Hawaii. Above mean sea level Above ground level Canadian Radio-television and Telecommunications Commission List of broadcast station classes United States Federal Communications Commission 47 CFR Part 73 Index FCC: Mass Media Calculated Contours FCC: HAAT Calculator "Superpower" Grandfathered FM stations
Oklahoma City shortened to OKC, is the capital and largest city of the U. S. state of Oklahoma. The county seat of Oklahoma County, the city ranks 27th among United States cities in population; the population grew following the 2010 Census, with the population estimated to have increased to 643,648 as of July 2017. As of 2015, the Oklahoma City metropolitan area had a population of 1,358,452, the Oklahoma City-Shawnee Combined Statistical Area had a population of 1,459,758 residents, making it Oklahoma's largest metropolitan area. Oklahoma City's city limits extend into Canadian and Pottawatomie counties, though much of those areas outside the core Oklahoma County area are suburban or rural; the city ranks as the ninth-largest city in the United States by total area when including consolidated city-counties. Lying in the Great Plains region, Oklahoma City has one of the world's largest livestock markets. Oil, natural gas, petroleum products and related industries are the largest sector of the local economy.
The city is in the middle of an active oil field and oil derricks dot the capitol grounds. The federal government employs large numbers of workers at Tinker Air Force Base and the United States Department of Transportation's Mike Monroney Aeronautical Center. Oklahoma City is on the I-35 Corridor, one of the primary travel corridors south into neighboring Texas and Mexico and north towards Wichita and Kansas City. Located in the state's Frontier Country region, the city's northeast section lies in an ecological region known as the Cross Timbers; the city was founded during the Land Run of 1889 and grew to a population of over 10,000 within hours of its founding. The city was the scene of the April 19, 1995 bombing of the Alfred P. Murrah Federal Building, in which 168 people died, it was the deadliest terror attack in the history of the United States until the attacks of September 11, 2001, remains the deadliest act of domestic terrorism in U. S. history. Since the time weather records have been kept, Oklahoma City has been struck by thirteen strong tornadoes.
Since 2008, Oklahoma City has been home to the National Basketball Association's Oklahoma City Thunder, who play their home basketball games at the Chesapeake Energy Arena. Oklahoma City was settled on April 22, 1889, when the area known as the "Unassigned Lands" was opened for settlement in an event known as "The Land Run"; some 10,000 homesteaders settled the area. The town grew quickly. Early leaders of the development of the city included Anton Classen, John Shartel, Henry Overholser and James W. Maney. By the time Oklahoma was admitted to the Union in 1907, Oklahoma City had surpassed Guthrie, the territorial capital, as the new state's population center and commercial hub. Soon after, the capital was moved from Guthrie to Oklahoma City. Oklahoma City was a major stop on Route 66 during the early part of the 20th century. Before World War II, Oklahoma City developed major stockyards, attracting jobs and revenue in Chicago and Omaha, Nebraska. With the 1928 discovery of oil within the city limits, Oklahoma City became a major center of oil production.
Post-war growth accompanied the construction of the Interstate Highway System, which made Oklahoma City a major interchange as the convergence of I-35, I-40, I-44. It was aided by federal development of Tinker Air Force Base. In 1950, the Census Bureau reported city's population as 8.6 % 90.7 % white. Patience Latting was elected Mayor of Oklahoma City in 1971. Latting was the first woman to serve as mayor of a U. S. city with over 350,000 residents. Like many other American cities, center city population declined in the 1970s and 1980s as families followed newly constructed highways to move to newer housing in nearby suburbs. Urban renewal projects in the 1970s, including the Pei Plan, removed older structures but failed to spark much new development, leaving the city dotted with vacant lots used for parking. A notable exception was the city's construction of the Myriad Gardens and Crystal Bridge, a botanical garden and modernistic conservatory in the heart of downtown. Architecturally significant historic buildings lost to clearances were the Criterion Theater, the Baum Building, the Hales Building, the Biltmore Hotel.
In 1993, the city passed a massive redevelopment package known as the Metropolitan Area Projects, intended to rebuild the city's core with civic projects to establish more activities and life to downtown. The city added a new baseball park. Water taxis transport passengers within the district, adding activity along the canal. MAPS has become one of the most successful public-private partnerships undertaken in the U. S. exceeding $3 billion in private investment as of 2010. As a result of MAPS, the population living in downtown housing has exponentially increased, together with demand for additional residential and retail amenities, such as grocery and shops. Since the MAPS projects' completion, the downtown area has seen continued
In broadcasting and radio communications, a call sign is a unique designation for a transmitter station. In the United States of America, they are used for all FCC-licensed transmitters. A call sign can be formally assigned by a government agency, informally adopted by individuals or organizations, or cryptographically encoded to disguise a station's identity; the use of call signs as unique identifiers dates to the landline railroad telegraph system. Because there was only one telegraph line linking all railroad stations, there needed to be a way to address each one when sending a telegram. In order to save time, two-letter identifiers were adopted for this purpose; this pattern continued in radiotelegraph operation. These were not globally unique, so a one-letter company identifier was added. By 1912, the need to identify stations operated by multiple companies in multiple nations required an international standard. Merchant and naval vessels are assigned call signs by their national licensing authorities.
In the case of states such as Liberia or Panama, which are flags of convenience for ship registration, call signs for larger vessels consist of the national prefix plus three letters. United States merchant vessels are given call signs beginning with the letters "W" or "K" while US naval ships are assigned call signs beginning with "N". Both ships and broadcast stations were assigned call signs in this series consisting of three or four letters. Ships equipped with Morse code radiotelegraphy, or life boat radio sets, Aviation ground stations, broadcast stations were given four letter call signs. Maritime coast stations on high frequency were assigned three letter call signs; as demand for both marine radio and broadcast call signs grew American-flagged vessels with radiotelephony only were given longer call signs with mixed letters and numbers. Leisure craft with VHF radios may not be assigned call signs, in which case the name of the vessel is used instead. Ships in the US still wishing to have a radio license are under FCC class SA: "Ship recreational or voluntarily equipped."
Those calls follow the land mobile format of the initial letter K or W followed by 1 or 2 letters followed by 3 or 4 numbers. U. S. Coast Guard small boats have a number, shown on both bows in which the first two digits indicate the nominal length of the boat in feet. For example, Coast Guard 47021 refers to the 21st in the series of 47-foot motor lifeboats; the call sign might be abbreviated to the final two or three numbers during operations, for example: Coast Guard zero two one. Aviation mobile stations equipped with radiotelegraphy were assigned five letter call signs.. Land Stations in Aviation were assigned four letter call signs; these call signs were phased out in the 1960s when flight radio officers were no longer required on international flights. USSR kept FRO's for the Moscow-Havana run until around 2000. All signs in aviation are derived from several different policies, depending upon the type of flight operation and whether or not the caller is in an aircraft or at a ground facility.
In most countries, unscheduled general aviation flights identify themselves using the call sign corresponding to the aircraft's registration number. In this case, the call sign is spoken using the International Civil Aviation Organization phonetic alphabet. Aircraft registration numbers internationally follow the pattern of a country prefix, followed by a unique identifier made up of letters and numbers. For example, an aircraft registered as N978CP conducting a general aviation flight would use the call sign November-niner-seven-eight-Charlie-Papa. However, in the United States a pilot of an aircraft would omit saying November, instead use the name of the aircraft manufacturer or the specific model. At times, general aviation pilots might omit additional preceding numbers and use only the last three numbers and letters; this is true at uncontrolled fields when reporting traffic pattern positions or at towered airports after establishing two-way communication with the tower controller. For example, Skyhawk eight-Charlie-Papa, left base.
In most countries, the aircraft call sign or "tail number"/"tail letters" are linked to the international radio call sign allocation table and follow a convention that aircraft radio stations receive call signs consisting of five letters. For example, all British civil aircraft have a five-letter call sign beginning with the letter G. Canadian aircraft have a call sign beginning with C–F or C–G, such as C–FABC. Wing In Ground-effect vehicles in Canada are eligible to receive C–Hxxx call signs, ultralight aircraft receive C-Ixxx call signs. In days gone by American aircraft used five letter call signs, such as KH–ABC, but they were replaced prior to World War II by the current American system of civilian aircraft call signs. Radio call signs used for communication in manned spaceflight is not formalized or regulated to the same degree as for aircraft; the three nations curren
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