Radio is the technology of signalling or communicating using radio waves. Radio waves are electromagnetic waves of frequency between 300 gigahertz, they are generated by an electronic device called a transmitter connected to an antenna which radiates the waves, received by a radio receiver connected to another antenna. Radio is widely used in modern technology, in radio communication, radio navigation, remote control, remote sensing and other applications. In radio communication, used in radio and television broadcasting, cell phones, two-way radios, wireless networking and satellite communication among numerous other uses, radio waves are used to carry information across space from a transmitter to a receiver, by modulating the radio signal in the transmitter. In radar, used to locate and track objects like aircraft, ships and missiles, a beam of radio waves emitted by a radar transmitter reflects off the target object, the reflected waves reveal the object's location. In radio navigation systems such as GPS and VOR, a mobile receiver receives radio signals from navigational radio beacons whose position is known, by measuring the arrival time of the radio waves the receiver can calculate its position on Earth.
In wireless remote control devices like drones, garage door openers, keyless entry systems, radio signals transmitted from a controller device control the actions of a remote device. Applications of radio waves which do not involve transmitting the waves significant distances, such as RF heating used in industrial processes and microwave ovens, medical uses such as diathermy and MRI machines, are not called radio; the noun radio is used to mean a broadcast radio receiver. Radio waves were first identified and studied by German physicist Heinrich Hertz in 1886; the first practical radio transmitters and receivers were developed around 1895-6 by Italian Guglielmo Marconi, radio began to be used commercially around 1900. To prevent interference between users, the emission of radio waves is regulated by law, coordinated by an international body called the International Telecommunications Union, which allocates frequency bands in the radio spectrum for different uses. Radio waves are radiated by electric charges undergoing acceleration.
They are generated artificially by time varying electric currents, consisting of electrons flowing back and forth in a metal conductor called an antenna. In transmission, a transmitter generates an alternating current of radio frequency, applied to an antenna; the antenna radiates the power in the current as radio waves. When the waves strike the antenna of a radio receiver, they push the electrons in the metal back and forth, inducing a tiny alternating current; the radio receiver connected to the receiving antenna detects this oscillating current and amplifies it. As they travel further from the transmitting antenna, radio waves spread out so their signal strength decreases, so radio transmissions can only be received within a limited range of the transmitter, the distance depending on the transmitter power, antenna radiation pattern, receiver sensitivity, noise level, presence of obstructions between transmitter and receiver. An omnidirectional antenna transmits or receives radio waves in all directions, while a directional antenna or high gain antenna transmits radio waves in a beam in a particular direction, or receives waves from only one direction.
Radio waves travel through a vacuum at the speed of light, in air at close to the speed of light, so the wavelength of a radio wave, the distance in meters between adjacent crests of the wave, is inversely proportional to its frequency. In radio communication systems, information is carried across space using radio waves. At the sending end, the information to be sent is converted by some type of transducer to a time-varying electrical signal called the modulation signal; the modulation signal may be an audio signal representing sound from a microphone, a video signal representing moving images from a video camera, or a digital signal consisting of a sequence of bits representing binary data from a computer. The modulation signal is applied to a radio transmitter. In the transmitter, an electronic oscillator generates an alternating current oscillating at a radio frequency, called the carrier wave because it serves to "carry" the information through the air; the information signal is used to modulate the carrier, varying some aspect of the carrier wave, impressing the information on the carrier.
Different radio systems use different modulation methods: AM - in an AM transmitter, the amplitude of the radio carrier wave is varied by the modulation signal. FM - in an FM transmitter, the frequency of the radio carrier wave is varied by the modulation signal. FSK - used in wireless digital devices to transmit digital signals, the frequency of the carrier wave is shifted periodically between two frequencies that represent the two binary digits, 0 and 1, to transmit a sequence of bits. OFDM - a family of complicated digital modulation methods widely used in high bandwidth systems such as WiFi networks, digital television broadcasting, digital audio broadcasting to transmit digital data using a minimum of radio spectrum bandwidth. OFDM has higher spectral efficiency and more resistance to fading than AM or FM. Multiple radio carrier waves spaced in frequency are transmitted within the radio channel, with each carrier modulated with bits from the incoming bitstream
A slogan is a memorable motto or phrase used in a clan, commercial and other context as a repetitive expression of an idea or purpose, with the goal of persuading members of the public or a more defined target group. The Oxford Dictionary of English defines a slogan as "a short and striking or memorable phrase used in advertising." A slogan has the attributes of being memorable concise and appealing to the audience. The word slogan is derived from slogorn, an Anglicisation of the Scottish Gaelic and Irish sluagh-ghairm. Slogans vary from the visual to the chanted and the vulgar, their simple rhetorical nature leaves little room for detail and a chanted slogan may serve more as social expression of unified purpose than as communication to an intended audience. George E. Shankel's research states that, "English-speaking people began using the term by 1704." The term at that time meant "the distinctive note, phrase or cry of any person or body of persons." Slogans were common throughout the European continent during the Middle Ages.
Crimmins' research suggests that brands are an valuable corporate asset, can make up a lot of a business's total value. With this in mind, if we take into consideration Keller's research, which suggests that a brand is made up of three different components; these include, name and slogan. Brands names and logos both can be changed by the way. Therefore, the slogan has a large job in portraying the brand. Therefore, the slogan should create a sense of likability in order for the brand name to be likable and the slogan message clear and concise. Dass, Kohli, & Thomas' research suggests that there are certain factors that make up the likability of a slogan; the clarity of the message the brand is trying to encode within the slogan. The slogan emphasizes the benefit of the service it is portraying; the creativity of a slogan is another factor that had a positive effect on the likability of a slogan. Lastly, leaving the brand name out of the slogan will have a positive effect on the likability of the brand itself.
Advertisers must keep into consideration these factors when creating a slogan for a brand, as it shows a brand is a valuable asset to a company, with the slogan being one of the three main components to a brands' image. The original usage refers to the usage as a clan motto among Highland clans. Marketing slogans are called taglines in the United States or straplines in the United Kingdom. Europeans use the terms baselines, claims or pay-offs. "Sloganeering" is a derogatory term for activity which degrades discourse to the level of slogans. Slogans are used to convey a message about the service or cause that it is representing, it written as a song. Slogans are used to capture the attention of the audience it is trying to reach. If the slogan is used for commercial purposes it is written to be memorable/catchy in order for a consumer to associate the slogan with the product it is representing. A slogan is part of the production aspect that helps create an image for the product, service or cause it's representing.
A slogan can be a few simple words used to form a phrase. In commercial advertising, corporations will use a slogan as part of promotional activity. Slogans can become a global way of identifying good or service, for example Nike's slogan'Just Do It' helped establish Nike as an identifiable brand worldwide. Slogans should catch the audience's attention and influence the consumer's thoughts on what to purchase; the slogan is used by companies to affect the way consumers view their product compared to others. Slogans can provide information about the product, service or cause its advertising; the language used in the slogans is essential to the message. Current words used can trigger different emotions; the use of good adjectives makes for an effective slogan. When a slogan is used for advertising purposes its goal is to sell the product or service to as many consumers through the message and information a slogan provides. A slogan's message can include information about the quality of the product.
Examples of words that can be used to direct the consumer preference towards a current product and its qualities are: good, real, great, perfect and pure. Slogans can influence. Slogans offer information to consumers in an creative way. A slogan can be used for a powerful cause; the slogan can be used to raise awareness about a current cause. A slogan should be clear with a supporting message. Slogans, when combined with action, can provide an influential foundation for a cause to be seen by its intended audience. Slogans, whether used for advertising purpose or social causes, deliver a message to the public that shapes the audiences' opinion towards the subject of the slogan. "It is well known that the text a human hears or reads constitutes 7% of the received information. As a result, any slogan possesses a support
Here Comes the Sun
"Here Comes the Sun" is a song written by George Harrison, first released on the Beatles' 1969 album Abbey Road. Along with "Something" and "While My Guitar Gently Weeps", it is one of Harrison's best-known compositions from the Beatles era; the song was written at the country house of his friend Eric Clapton, where Harrison had chosen to play truant for the day, to avoid attending a meeting at the Beatles' Apple Corps organisation. The lyrics reflect the composer's relief at both the arrival of spring and the temporary respite he was experiencing from the band's business affairs; the Beatles recorded "Here Comes the Sun" at London's EMI Studios in the summer of 1969. Led by Harrison's acoustic guitar, the recording features Moog synthesizer, which he had introduced to the Beatles' sound after acquiring an early model of the instrument in California. Reflecting the continued influence of Indian classical music on Harrison's writing, the composition includes a series of unusual time changes. "Here Comes the Sun" has received acclaim from music critics.
Combined with his other contribution to Abbey Road, "Something", it gained for Harrison the level of recognition as a songwriter, reserved for his bandmates John Lennon and Paul McCartney. Harrison played the song during many of his rare live performances as a solo artist, including at the Concert for Bangladesh in 1971 and, with Paul Simon, during his appearance on Saturday Night Live in 1976. Richie Havens and Steve Harley & Cockney Rebel each had hit singles with "Here Comes the Sun" in the 1970s. Nina Simone, George Benson, Booker T. & the M. G.'s, Peter Tosh and Joe Brown are among the many other artists. The early months of 1969 were a difficult period for Harrison: he had quit the band temporarily, he was arrested for marijuana possession, he had his tonsils removed. Harrison states in his autobiography, I, Me, Mine: "Here Comes the Sun" was written at the time when Apple was getting like school, where we had to go and be businessmen:'Sign this' and'sign that.' Anyway, it seems as if winter in England goes on forever, by the time spring comes you deserve it.
So one day I decided I went over to Eric Clapton's house. The relief of not having to go see all those dopey accountants was wonderful, I walked around the garden with one of Eric's acoustic guitars and wrote "Here Comes the Sun"; as Clapton states in his autobiography, the house in question, in Ewhurst, Surrey, is known as Hurtwood Edge. When interviewed in the Martin Scorsese documentary George Harrison: Living in the Material World, Clapton said he believed the month was April. Data from two meteorological stations in the London area show that April 1969 set a record for sunlight hours for the 1960s; the Greenwich station recorded 189 hours for April, a high, not beaten until 1984. The Greenwich data show that February and March were much colder than the norm for the 1960s, which would account for Harrison's reference to a "long, lonely winter"; the song is in the key of A major. The main refrain uses a IV to V-of-V progression; the melody in the verse and refrain follows the pentatonic scale from E up to C♯.
One feature is the increasing syncopation in the vocal parts. Another feature is the guitar flat-picking that embellishes the E7 chord from 2:03 to 2:11, creating tension for resolution on the tonic A chord at "Little darlin' "; the bridge involves a ♭III-♭VII-IV-I-V7 triple descending 4th progression as the vocals move from "Sun" to "sun" to "sun" to "comes" and the additional 4th descent to a V7 chord. The lyric here has been described as taking "on the quality of a meditator's mantra"; the song features extreme 4/4 and a sequence of 11/8 + 4/4 + 7/8 in the bridge, phrasing interludes which Harrison drew from Indian music influences. In the second verse the Moog synthesizer doubles the solo guitar line and in the third verse the Moog adds a counter melody an octave above; the last four bars juxtapose the guitar break with a repeat of the bridge. Harrison, Paul McCartney and Ringo Starr recorded the rhythm track in 13 takes on 7 July 1969. John Lennon did not contribute to the song. Towards the end of the session Harrison spent an hour re-recording his acoustic guitar part.
He capoed his guitar on the 7th fret. He used the same technique on his 1965 song "If I Needed Someone", which shares a similar melodic pattern; the following day he taped his lead vocals, he and McCartney recorded their backing vocals twice to give a fuller sound. A harmonium and handclaps were added on 16 July. Harrison added an electric guitar run through a Leslie speaker on 6 August, the orchestral parts were added on 15 August. "Here Comes the Sun" was completed four days with the addition of Harrison's Moog synthesizer part. The master tapes reveal that Harrison recorded a guitar solo, not included in the final mix at that time. Abbey Road was released on 26 September 1969 with "Here Comes the Sun" sequenced as the opening track on side two of the LP. Along with "Something", issued as a single from the album, the song established Harrison as a compos
HD Radio is a trademarked term for Xperi's in-band on-channel digital radio technology used by AM and FM radio stations to transmit audio and data by using a digital signal embedded "on-frequency" above and below a station's standard analog signal, providing the means to listen to the same program in either HD or as a standard broadcast. The HD format provides the means for a single radio station to broadcast one or more different programs in addition to the program being transmitted on the radio station's analog channel, it was developed by iBiquity. In September 2015 iBiquity was acquired by DTS bringing the HD Radio technology under the same banner as DTS' eponymous theater surround sound systems.. It was acquired by Xperi in 2016, it was selected by the U. S. Federal Communications Commission in 2002 as a digital audio broadcasting method for the United States, is the only digital system approved by the FCC for digital AM/FM broadcasts in the United States, it is known as NRSC-5, with the latest version being NRSC-5-D.
Other digital radio systems include FMeXtra, Digital Audio Broadcasting, Digital Radio Mondiale, Compatible AM-Digital. While HD Radio does allow for an all-digital mode, this system is used by some AM and FM radio stations to simulcast both digital and analog audio within the same channel as well as to add new FM channels and text information. Although HD Radio broadcasting's content is free-to-air, listeners must purchase new receivers in order to receive the digital portion of the signal. By May 2018, HD Radio technology was claimed to be used by more than 3500 individual services in the United States; this compares with more than 2200 services operating with the DAB system. HD Radio increases the bandwidth required in the FM band to 400 kHz for the analog/digital hybrid version; this makes adoption outside the United States problematic. In the United States the FM broadcast band channels have a spacing of 200 kHz, as opposed to the 100 kHz, normal elsewhere; the 200 kHz spacing means that in practice, stations having concurrent or adjacent coverage areas will not be spaced at less than 400 kHz in order to respect protection ratios which would not be met with 200 kHz spacing.
This leaves space for the digital sidebands. Outside the US, spacing can be 300 kHz; the FCC has not indicated any intent to force off analog radio broadcasts as it has with analog television broadcasts, as it would not result in the recovery of any radio spectrum rights which could be sold. Thus, there is no deadline. In addition, there are many more analog AM/FM radio receivers than there were analog televisions, many of these are car stereos or portable units that cannot be upgraded. Digital information is transmitted using OFDM with an audio compression algorithm called HDC.. HD Radio equipped stations pay a one-time licensing fee for converting their primary audio channel to iBiquity's HD Radio technology, 3% of incremental net revenues for any additional digital subchannels; the cost of converting a radio station can run between $100,000 and $200,000. Receiver manufacturers pay a royalty. If the primary digital signal is lost the HD Radio receiver will revert to the analog signal, thereby providing seamless operation between the newer and older transmission methods.
The extra HD-2 and HD-3 streams are not simulcast on analog, causing the sound to drop-out or "skip" when digital reception degrades. Alternatively the HD Radio signal can revert to a more-robust 20 kilobit per second stream, though the sound is reduced to AM-like quality. Datacasting is possible, with metadata providing song titles or artist information. IBiquity Digital claims that the system approaches CD quality audio and offers reduction of both interference and static. Sending pure digital data through the 20 kilohertz AM channel is equivalent to sending data through two 33 kbit/s analog telephone lines, thus limiting the maximum throughput possible. By using spectral band replication the HDC+SBR codec is able to simulate the recreation of sounds up to 15,000 Hz, thus achieving moderate quality on the bandwidth-tight AM band; the HD Radio AM hybrid mode offers two options which can carry 40 or 60 kbit/s of data, but most AM digital stations default to the more-robust 40 kbit/s mode which features redundancy.
HD Radio provides a pure digital mode, which lacks an analog signal for fallback and instead reverts to a 20 kbit/s signal during times of poor reception. The pure digital mode transmissions will stay within the AM station's channel instead of spilling into the channels next to the station transmitting "HD radio" as the hybrid stations do; the AM version of HD Radio technology uses the 20 kHz channel, overlaps 5 kHz into the opposite sideband of the adjacent channel on both sides. When operating in pure digital mode, the AM HD Radio signal fits inside a standard 20 kHz channel or an extended 30 kHz channel, at the discretion of the station manager; as AM radio stations are spaced at 9 kHz or 10 kHz intervals, much of the digital information overlaps adjacent channels when in hybrid mode. Some nigh
KTRK-TV, virtual and VHF digital channel 13, is an ABC owned-and-operated television station licensed to Houston, United States. The station is owned by the ABC Owned Television Stations subsidiary of The Walt Disney Company. KTRK's studios are located on Bissonnet Street in the Upper Kirby district, its transmitter is located near Missouri City, in unincorporated northeastern Fort Bend County; the station grew out of the Federal Communications Commission-imposed VHF "freeze", when three entities vying for the channel 13 assignment, including the Houston Chronicle, decided to merge as Houston Consolidated Television. The group bought the studio facilities of KNUZ-TV, a DuMont affiliate which had gone dark; the station first signed on the air on November 20, 1954, as KTRK-TV. The station took the ABC affiliation from KPRC-TV and has stayed aligned with the network since its debut; the station's original studio facilities were located at 4513 Cullen Boulevard. Like many stations located on "unlucky" channel 13, it used a black cat as its mascot.
In 1955, the Chronicle bought out its partners. Although this theoretically left the paper free to change its callsign to KTRH-TV to match its radio station, it opted not to. However, for years it called itself "The Houston Chronicle Station." Soon afterward, the station moved to its current Bissonnet Street facility. The studio was the first domed structure in town, predating the better-known Astrodome by ten years. Both projects were designed by Hermon Lloyd. Early programs reflected themes of the day; some of the more popular local shows included: Kitirik: a children's program, hosted by an actress in a cat costume. Cadet Don: A space-themed children's adventure program that focused on the exploits of an interstellar adventurer and the locations he visited, his alien puppet friend Seymour was from the planet Katark. Dialing for Dollars: A game show of sorts where a viewer would be phoned by the host and would win a cash prize by answering questions. Good Morning Houston: The successor to Dialing for Dollars, which debuted in the late 1970s and expanded to include discussions on local events and topics important to viewer's lifestyles.
In 1967, the Chronicle sold KTRK to Capital Cities Broadcasting, earning a handsome return on its 1937 purchase of KTRH. Under Capital Cities ownership, KTRK introduced its "Circle 13" logo –, loosely patterned after the Circle 7 logo long used by ABC stations and affiliates broadcasting on channel 7 – in 1971; the original version, used until 1995, was set in a Helvetica typeface, with the bottom of the "3" trailing off outside the circle --a nod to livestock branding of the Old West. Capital Cities bought ABC in 1986, making KTRK an ABC owned-and-operated station and the first network-owned television station in the state of Texas; that year, the trailing portion of the station's logo was "trimmed" and was turned horizontal in a similar fashion to the present-day version. Capital Cities/ABC was sold to The Walt Disney Company in early 1996. Not long after, the new Disney-led ownership directed KTRK-TV to clear the entire ABC schedule, though there have been instances where local special events have aired in place of network programming.
On April 30, 2000, a dispute between Disney and Time Warner Cable resulted in KTRK being pulled from TWC's Houston service area for over 24 hours. Other ABC stations in markets served by Time Warner Cable, such as New York City, Los Angeles and Raleigh-Durham, were affected by the outage before the FCC forced the provider to restore the affected ABC stations to those areas on May 2; the station's digital channel is multiplexed: KTRK-TV discontinued regular programming on its analog signal, over VHF channel 13, on June 12, 2009, as part of the federally mandated transition from analog to digital television. As most of ABC's owned-and-operated stations moved their digital channels to their former analog allocation post-transition, the station's digital signal relocated from its pre-transition UHF channel 32 to VHF channel 13 for post-transition operations. Under Capital Cities ownership, KTRK preempted some ABC programs, though not nearly as much as some of the network's other affiliates, such as Philadelphia sister station WPVI-TV.
It ran The Edge of Night in pattern at 3 p.m. CT from the program's ABC premiere. In mid-April 1977, it was dropped when KTRK added their Live at 5 newscast which would have cut the station's profitable afternoon staple Million Dollar Movie from two hours to 90 minutes; the less profitable Edge was dropped instead, Million Dollar Movie was pushed back into the 3-5 time slot until September 1992. Many of the other programs that channel 13 declined to air were not run in many markets, though KTRK did preempt the first half-hour of Good Morning America in favor of a local newscast, continuing into the early 1990s
The Beatles were an English rock band formed in Liverpool in 1960. The line-up of John Lennon, Paul McCartney, George Harrison and Ringo Starr led the band to be regarded as the foremost and most influential in history. With a sound rooted in skiffle, beat and 1950s rock and roll, the group were integral to the evolution of pop music into an art form, to the development of the counterculture of the 1960s, they incorporated elements of classical music, older pop forms, unconventional recording techniques in innovative ways, in years experimented with a number of musical styles ranging from pop ballads and Indian music to psychedelia and hard rock. As they continued to draw influences from a variety of cultural sources, their musical and lyrical sophistication grew, they came to be seen as embodying the era's sociocultural movements. Led by primary songwriters Lennon and McCartney, the Beatles built their reputation playing clubs in Liverpool and Hamburg over a three-year period from 1960 with Stuart Sutcliffe playing bass.
The core trio of Lennon, McCartney and Harrison, together since 1958, went through a succession of drummers, including Pete Best, before asking Starr to join them in 1962. Manager Brian Epstein moulded them into a professional act, producer George Martin guided and developed their recordings expanding their domestic success after their first hit, "Love Me Do", in late 1962; as their popularity grew into the intense fan frenzy dubbed "Beatlemania", the band acquired the nickname "the Fab Four", with Epstein and other members of the band's entourage sometimes given the informal title of "fifth Beatle". By early 1964, the Beatles were international stars, leading the "British Invasion" of the United States pop market, breaking numerous sales records, they soon made their motion-picture debut with A Hard Day's Night. From 1965 onwards, they produced innovative recordings, including the albums Rubber Soul, Sgt. Pepper's The Beatles and Abbey Road. In 1968, they founded Apple Corps, a multi-armed multimedia corporation that continues to oversee projects related to the band's legacy.
After the group's break-up in 1970, all four members enjoyed success as solo artists. Lennon was shot and killed in December 1980. McCartney and Starr remain musically active; the Beatles are the best-selling band in history, with estimated sales of over 800 million records worldwide. They are the best-selling music artists in the US, with certified sales of over 178 million units, have had more number-one albums on the British charts, have sold more singles in the UK, than any other act; the group were inducted into the Rock and Roll Hall of Fame in 1988, all four main members were inducted individually between 1994 and 2015. In 2008, the group topped Billboard magazine's list of the all-time most successful artists; the band have received an Academy Award and fifteen Ivor Novello Awards. They were collectively included in Time magazine's compilation of the twentieth century's 100 most influential people. In March 1957, John Lennon aged sixteen, formed a skiffle group with several friends from Quarry Bank High School in Liverpool.
They called themselves the Blackjacks, before changing their name to the Quarrymen after discovering that a respected local group was using the other name. Fifteen-year-old Paul McCartney joined them as a rhythm guitarist shortly after he and Lennon met that July. In February 1958, McCartney invited his friend George Harrison to watch the band; the fifteen-year-old auditioned for Lennon, impressing him with his playing, but Lennon thought Harrison was too young for the band. After a month of Harrison's persistence, during a second meeting, he performed the lead guitar part of the instrumental song "Raunchy" on the upper deck of a Liverpool bus, they enlisted him as their lead guitarist. By January 1959, Lennon's Quarry Bank friends had left the group, he began his studies at the Liverpool College of Art; the three guitarists, billing themselves at least three times as Johnny and the Moondogs, were playing rock and roll whenever they could find a drummer. Lennon's art school friend Stuart Sutcliffe, who had just sold one of his paintings and was persuaded to purchase a bass guitar, joined in January 1960, it was he who suggested changing the band's name to Beatals, as a tribute to Buddy Holly and the Crickets.
They used this name until May, when they became the Silver Beetles, before undertaking a brief tour of Scotland as the backing group for pop singer and fellow Liverpudlian Johnny Gentle. By early July, they had refashioned themselves as the Silver Beatles, by the middle of August shortened the name to The Beatles. Allan Williams, the Beatles' unofficial manager, arranged a residency for them in Hamburg, but lacking a full-time drummer they auditioned and hired Pete Best in mid-August 1960; the band, now a five-piece, left four days contracted to club owner Bruno Koschmider for what would be a 31⁄2-month residency. Beatles historian Mark Lewisohn writes: "They pulled into Hamburg at dusk on 17 August, the time when the red-light area comes to life... flashing neon lights screamed out the various entertainment on offer, while scantily clad women sat unabashed in shop windows waiting for business opportunities." Koschmider had converted a couple of strip clubs in the district into music venues, he placed the Beatles at the Indra Club.
Broadcast relay station
A broadcast relay station known as a satellite station, relay transmitter, broadcast translator, re-broadcaster, repeater or complementary station, is a broadcast transmitter which repeats the signal of a radio or television station to an area not covered by the originating station. It expands the broadcast range of a television or radio station beyond the primary signal's original coverage or improves service in the original coverage area; the stations may be used to create a single-frequency network. They may be used by an FM or AM radio station to establish a presence on the other band. A re-broadcaster may be owned by a community group, rather than the owner of the primary station. WHLS/WHLX in Port Huron, Michigan purchased a translator and switched to an alternative rock format shortly afterwards without mentioning the original FM translator, except for its required top-of-the-hour ID. No AM frequencies have been mentioned. In its simplest form, a broadcast translator is a facility created to receive a terrestrial broadcast over the air on one frequency and rebroadcast the same signal on another frequency.
These stations are used in television and radio to cover areas which are not adequately covered by a station's main signal. They can be used to expand market coverage by duplicating programming on another band. Relays which broadcast within the parent station's coverage area on the same channel are known in the U. S. as booster stations. Signals from the stations may interfere with each other without careful antenna design. Radio interference can be avoided by using atomic time, obtained from GPS satellites, to synchronize co-channel stations in a single-frequency network. Analog television stations cannot have same-channel boosters unless opposite polarization is used, due to video synchronization issues such as ghosting. In the U. S. no new on-channel UHF signal boosters have been authorized since July 11, 1975. A distributed transmission system uses several medium-power stations on the same frequency to cover a broadcast area, rather than one high-power station with repeaters on a different frequency.
Although digital television stations are technically capable of sharing a channel, this is more difficult with the 8VSB modulation and unvariable guard interval used in ATSC standards than with the orthogonal frequency-division multiplexing used in the European and Australian DVB-T standard. A distributed transmission system would have stringent synchronization requirements, requiring each transmitter to receive its signal from a central source for broadcast at a GPS-synchronized time. A DTS does not use broadcast repeaters in the conventional sense, since they cannot receive a signal from a main terrestrial broadcast transmitter for rebroadcast; the use of virtual channels is another alternative, although this may cause the same channel to appear several times in a receiver – once for each relay station – and require the user to tune to the best one. Although boosters or DTS cause all relay stations to appear as one signal, they require careful engineering to avoid interference; some licensed stations simulcast another station.
Relay stations in name only, they are licensed like any other station. Although this is unregulated in the U. S. and permitted in Canada, the U. S. Federal Communications Commission regulates radio formats to ensure diversity in programming. U. S. satellite stations may request an FCC exemption from requirements for a properly staffed broadcast studio in the city of license. The stations cover large, sparsely populated regions or operate as statewide non-commercial educational radio and television systems. A television re-broadcaster sells local advertising for broadcast only on the local transmitter, may air a limited amount of programming distinct from its parent station; some "semi-satellites" broadcast local news or separate news segments during part of the newscast. CHEX-TV-2 in Oshawa, Ontario aired daily late-afternoon and early-evening news and community programs separate from its parent station, CHEX-TV in Peterborough, Ontario; the FCC prohibits this on U. S. FM translator stations, only permitting it on licensed stations.
In some cases, a semi-satellite is a autonomous full-service station, programmed remotely through centralcasting or broadcast automation to avoid the cost of a local staff. CBLFT, an owned-and-operated station of the French-language network Ici Radio-Canada Télé in Toronto, is a de facto semi-satellite of its stronger Ottawa sibling CBOFT. A financially weak owned broadcaster in a small market can become a de facto semi-satellite by curtailing local production and relying on a owned station in a larger city for programming. Broadcast automation allows the substitution of syndicated programming or digital subchannel content which the broadcaster was unable to obtain for both cities; some defunct full-service stations have originate nothing. If programming from the parent station must be removed or substituted due to local sports blackouts, the modified signal is that of a semi-satellite station. Most broadcasters outside North America maintain a national network