FM broadcasting is a method of radio broadcasting that uses frequency modulation ( FM ) of the radio broadcast carrier wave. Invented in 1933 by American engineer Edwin Armstrong , wide-band FM is used worldwide to transmit high-fidelity sound over broadcast radio . FM broadcasting offers higher fidelity—more accurate reproduction of the original program sound—than other broadcasting techniques, such as AM broadcasting . It is also less susceptible to common forms of interference , having less static and popping sounds than are often heard on AM. Therefore, FM is used for most broadcasts of music and general audio (in the audio spectrum). FM radio stations use the very high frequency range of radio frequencies .
81-538: WABD (97.5 FM ) is an American radio station licensed to serve the community of Mobile, Alabama . The station, established in 1973 as WABB-FM, is owned and operated by Cumulus Media . Its studios are on Dauphin Street in Midtown Mobile, and its transmitter is near Spanish Fort, Alabama . This station began broadcasting a contemporary hit radio music branded as "97-5 WABD" on July 15, 2012. The shift from
162-615: A great impact in this format. Disc jockeys use a more relaxed sound than their younger counterparts. News and current events have a major impact on the older audience. Around the evening, urban AC stations play smooth jazz during the Quiet Storm program. Many of the urban AC radio stations implement slogans such as "Classic Soul & Today's R&B", "(City/Region)'s Old School and R&B Station", "The Best Mix of R&B", and "(City/Region)'s R&B Leader." Some popular nicknames for urban oldies stations include "Magic" (borrowed from
243-514: A monophonic broadcast, again the most common permitted maximum deviation is ±75 kHz. However, some countries specify a lower value for monophonic broadcasts, such as ±50 kHz. The bandwidth of an FM transmission is given by the Carson bandwidth rule which is the sum of twice the maximum deviation and twice the maximum modulating frequency. For a transmission that includes RDS this would be 2 × 75 kHz + 2 × 60 kHz = 270 kHz . This
324-557: A program feed for AM transmitters of AM/FM stations. SCA subcarriers are typically 67 kHz and 92 kHz. Initially the users of SCA services were private analog audio channels which could be used internally or leased, for example Muzak -type services. There were experiments with quadraphonic sound. If a station does not broadcast in stereo, everything from 23 kHz on up can be used for other services. The guard band around 19 kHz (±4 kHz) must still be maintained, so as not to trigger stereo decoders on receivers. If there
405-470: A stroke the previous week. Dittman's daughter Betsey succeeded him after relocating to Mobile from Chicago, Illinois . On February 17, 2012, the Dittman family announced on its website that it has decided to sell WABB-FM to Educational Media Foundation for $ 3.1 million. Following a day-long retrospective on the history of WABB, including its history on 1480 AM, on February 29, at Midnight, after bookending
486-473: A studio-to-transmitter link system. In April 1935, the AM subcarriers were replaced by FM subcarriers, 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-channel audio programs, binaural audio programs and a fax program. The original subcarrier frequency used at KE2XCC
567-525: Is added. VHF radio waves usually do not travel far beyond the visual horizon , so reception distances for FM stations are typically limited to 30–40 miles (50–60 km). They can also be blocked by hills and to a lesser extent by buildings. Individuals with more-sensitive receivers or specialized antenna systems, or who are located in areas with more favorable topography, may be able to receive useful FM broadcast signals at considerably greater distances. The knife edge effect can permit reception where there
648-422: Is also known as the necessary bandwidth . Random noise has a triangular spectral distribution in an FM system, with the effect that noise occurs predominantly at the higher 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
729-408: Is amplitude modulated onto a 38 kHz double-sideband suppressed-carrier (DSB-SC) signal, thus occupying 23 kHz to 53 kHz. A 19 kHz ± 2 Hz pilot tone , at exactly half the 38 kHz sub-carrier frequency and with a precise phase relationship to it, as defined by the formula below, is also generated. The pilot is transmitted at 8–10% of overall modulation level and used by
810-422: Is authorized for "hybrid" mode operation, wherein both the conventional analog FM carrier and digital sideband subcarriers are transmitted. The output power of an FM broadcasting transmitter is one of the parameters that governs how far a transmission will cover. The other important parameters are the height of the transmitting antenna and the antenna gain . Transmitter powers should be carefully chosen so that
891-596: Is designed to be capable of use alongside ARI despite using identical subcarrier frequencies. In the United States and Canada , digital radio services are deployed within the FM band rather than using Eureka 147 or the Japanese standard ISDB . This in-band on-channel approach, as do all digital radio techniques, makes use of advanced compressed audio . The proprietary iBiquity system, branded as HD Radio ,
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#1732790895479972-471: Is disagreement in the music industry over the use of the term urban in describing music genres and formats. In June 2020, Republic Records and artist management company Milk & Honey stated that they would drop the use of the word in relation to music of a black origin. These decisions came in the wake of the murder of George Floyd at the hands of police and the subsequent protests . Lance Venta of radio industry publication RadioInsight claimed that
1053-480: Is mainly the preserve of talk radio, news, sports, religious programming, ethnic (minority language) broadcasting and some types of minority interest music. This shift has transformed AM into the "alternative band" that FM once was. (Some AM stations have begun to simulcast on, or switch to, FM signals to attract younger listeners and aid reception problems in buildings, during thunderstorms, and near high-voltage wires. Some of these stations now emphasize their presence on
1134-671: Is no direct line of sight between broadcaster and receiver. The reception can vary considerably depending on the position. One example is the Učka mountain range, which makes constant reception of Italian signals from Veneto and Marche possible in a good portion of Rijeka , Croatia, despite the distance being over 200 km (125 miles). Other radio propagation effects such as tropospheric ducting and Sporadic E can occasionally allow distant stations to be intermittently received over very large distances (hundreds of miles), but cannot be relied on for commercial broadcast purposes. Good reception across
1215-405: Is one urban AC station whose playlist heavily emphasizes current material. While artists were once reluctant to be on urban AC because it made them look "old", by 2024, young people had become a major part of the format. With mainstream urban becoming more of a hip-hop format, R&B was less of a factor there. Urban AC played more of a role in introducing records and artists than it had been. It
1296-496: Is only suitable for text. A few proprietary systems are used for private communications. A variant of RDS is the North American RBDS or "smart radio" system. In Germany the analog ARI system was used prior to RDS to alert motorists that traffic announcements were broadcast (without disturbing other listeners). Plans to use ARI for other European countries led to the development of RDS as a more powerful system. RDS
1377-588: Is open to anyone who does not carry a prohibition and can put up the appropriate licensing and royalty fees. In 2010 around 450 such licences were issued. Urban AC Urban adult contemporary , often abbreviated as urban AC or UAC , (also known as adult R&B , ) is the name for a format of radio music, similar to an urban contemporary format. Radio stations using this format usually would not have hip hop music on their playlists, and generally include some mix of contemporary R&B and traditional R&B (while urban oldies stations emphasize only
1458-504: Is performed by a decoder, built into stereo receivers. Again, the decoder can use a switching technique to recover the left and right channels. In addition, for a given RF level at the receiver, the signal-to-noise ratio and multipath distortion for the stereo signal will be worse than for the mono receiver. For this reason many stereo FM receivers include a stereo/mono switch to allow listening in mono when reception conditions are less than ideal, and most car radios are arranged to reduce
1539-557: Is related to the transmitter 's RF power, the antenna gain , and antenna height . Interference from other stations is also a factor in some places. In the U.S, the FCC publishes curves that aid in calculation of this maximum distance as a function of signal strength at the receiving location. Computer modelling is more commonly used for this around the world. Many FM stations, especially those located in severe multipath areas, use extra audio compression /processing to keep essential sound above
1620-630: Is stereo, there will typically be a guard band between the upper limit of the DSBSC stereo signal (53 kHz) and the lower limit of any other subcarrier. Digital data services are also available. A 57 kHz subcarrier ( phase locked to the third harmonic of the stereo pilot tone) is used to carry a low-bandwidth digital Radio Data System signal, providing extra features such as station name, alternative frequency (AF), traffic data for satellite navigation systems and radio text (RT). This narrowband signal runs at only 1,187.5 bits per second , thus
1701-427: Is used. This applies to both mono and 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 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
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#17327908954791782-595: The Light Programme , Third Programme and Home Service . These three networks used the sub-band 88.0–94.6 MHz. The sub-band 94.6–97.6 MHz was later used for BBC and local commercial services. However, only when commercial broadcasting was introduced to the UK in 1973 did the use of FM pick up in Britain. With the gradual clearance of other users (notably Public Services such as police, fire and ambulance) and
1863-564: The Satellite Music Network format Urban Gold, which had 27 stations six months after starting October 1, 1993. Steve Harris, the SMN manager for urban radio, said no black radio stations had targeted adults over 35. Consultant Tony Gray said older adults did not like contemporary music, which had few tunes that had proved they could stand the test of time. And hip hop was becoming a bigger part of contemporary radio. Another factor
1944-610: The Southwest United States ). One of the first stations to play this type of music was WRKS-FM (98.7 Kiss FM). In December 1994, Emmis Broadcasting transformed Kiss FM into the first station to play urban oldies music on a regular basis. The format was an instant hit with black and white listeners around the Greater New York area , reaching to number two on the Arbitron ratings. Before WRKS, many of
2025-618: The adult contemporary format), "Mix" and "Star" (both borrowed from the Hot AC format), and " KISS-FM " (borrowed from top 40/CHR ). WBLS in New York City, which is the flagship station of the urban contemporary format, was one of the first stations to introduce the urban AC format in 1994. WRKS-FM (also in New York City) introduced the first 24-hour classic soul radio station in the country. Urban AC stations usually target
2106-471: The 18-49 and 25-54 age groups. Many urban AC stations rely heavily on syndicated programming such as The Steve Harvey Morning Show and The D. L. Hughley Show . Cumulus Media Networks also operates a 24/7 urban AC format delivered to affiliated stations via satellite, called " The Touch ", which is common on smaller- and medium-market stations featuring the urban AC format. KJLH in Los Angeles
2187-492: The 1970s and 1980s: A commercially unsuccessful noise reduction system used with FM radio in some countries during the late 1970s, Dolby FM was similar to Dolby B but used a modified 25 μs pre-emphasis time constant and a frequency selective companding arrangement to reduce noise. The pre-emphasis change compensates for the excess treble response that otherwise would make listening difficult for those without Dolby decoders. A similar system named High Com FM
2268-664: The 35% of the playlists that were rap/hip-hop at the time, while playing 65% non-rap urban currents, to wide acclaim. WJMO in Cleveland and WVOL in Nashville were some of the early converts. KHYS in Houston switched to the format in 1999. KCJZ in San Antonio followed suit 7 months later. Early in 1994, M Street Journal reported 33 radio stations in the format, compared to 14 a year earlier. Many of these were affiliates of
2349-571: The Educational Media Foundation announced that WLVM had been sold to Cumulus Broadcasting holding company Cumulus Licensing, LLC, as part of a multi-station deal and that several format shifts would take place simultaneously at noon on July 15, 2012. The Christian programming on WLVM moved to WDLT (98.3 FM), the urban AC format on WDLT moved to WABD (104.1 FM), and the CHR format on WABD moved to WLVM (97.5 FM). The FCC accepted
2430-665: The FCC announced the reassignment of the FM band to 90 channels from 88–106 MHz (which was soon expanded to 100 channels from 88–108 MHz). This shift, which the AM-broadcaster RCA had pushed for, made all the Armstrong-era FM receivers useless and delayed the expansion of FM. In 1961 WEFM (in the Chicago area) and WGFM (in Schenectady, New York ) were reported as the first stereo stations. By
2511-705: The FCC rules do not allow this mode of stereo operation. In 1969, Louis Dorren invented the Quadraplex system of single station, discrete, compatible four-channel FM broadcasting. There are two additional subcarriers in the Quadraplex system, supplementing the single one used in standard stereo FM. The baseband layout is as follows: The normal stereo signal can be considered as switching between left and right channels at 38 kHz, appropriately band-limited. The quadraphonic signal can be considered as cycling through LF, LR, RF, RR, at 76 kHz. Early efforts to transmit discrete four-channel quadraphonic music required
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2592-579: The FCC. The original Dorren Quadraplex System outperformed all the others and was chosen as the national standard for Quadraphonic FM broadcasting in the United States. The first commercial FM station to broadcast quadraphonic program content was WIQB (now called WWWW-FM ) in Ann Arbor / Saline, Michigan under the guidance of Chief Engineer Brian Jeffrey Brown. Various attempts to add analog noise reduction to FM broadcasting were carried out in
2673-456: The FM carrier . Modulation control (limiter) devices are used to prevent this. Systems more modern than FM broadcasting tend to use either programme-dependent variable pre-emphasis; e.g., dbx in the BTSC TV sound system, or none at all. Pre-emphasis and de-emphasis was used in the earliest days of FM broadcasting. According to a BBC report from 1946, 100 μs was originally considered in
2754-520: The FM band.) The medium wave band (known as the AM band because most stations using it employ amplitude modulation) was overcrowded in western Europe, leading to interference problems and, as a result, many MW frequencies are suitable only for speech broadcasting. Belgium , the Netherlands , Denmark and particularly Germany were among the first countries to adopt FM on a widespread scale. Among
2835-979: The FM radio band from 87.5-108.0 MHz to 76.1-108.0 MHz to enable the migration of AM radio stations in Brazilian capitals and large cities. FM broadcasting began in the late 1930s, when it was initiated by a handful of early pioneer experimental stations, including W1XOJ/W43B/WGTR (shut down in 1953) and W1XTG/ WSRS , both transmitting from Paxton, Massachusetts (now listed as Worcester, Massachusetts ); W1XSL/W1XPW/W65H/WDRC-FM/WFMQ/WHCN , Meriden, Connecticut; and W2XMN , KE2XCC , and WFMN , Alpine, New Jersey (owned by Edwin Armstrong himself, closed down upon Armstrong's death in 1954). Also of note were General Electric stations W2XDA Schenectady and W2XOY New Scotland, New York—two experimental FM transmitters on 48.5 MHz—which signed on in 1939. The two began regular programming, as W2XOY, on November 20, 1940. Over
2916-463: The L+R signal so the listener will hear both channels through the single loudspeaker. A stereo receiver will add the difference signal to the sum signal to recover the left channel, and subtract the difference signal from the sum to recover the right channel. The (L+R) signal is limited to 30 Hz to 15 kHz to protect a 19 kHz pilot signal. The (L−R) signal, which is also limited to 15 kHz,
2997-698: The US, but 75 μs subsequently adopted. 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
3078-555: The Urban music division. Hip Hop and R&B is leading the way for the surge in music sales and usage of streaming. Are the other positions, titles and departments within a record company going to change or dissolve? ... Do they realize the cultural power of Urban Music? In 2024, Billboard quoted P Music Group founder Michael Paran, who said of the magazine's Adult R&B chart, "the chart is named wrong ... Let's call it what it is: It's just R&B." More younger people were showing up on
3159-498: The WLVM license transfer application on July 10, 2012, and changed that station's call sign from WLVM to WABD on July 16, 2012, with the first song on the new frequency being "Starships" by Nicki Minaj . The sale of the station was finalized the following week. WLVM and WDLT operated under local marketing agreements until the sales were approved and the transactions consummated. The station has gone through many personalities through
3240-454: The assigned frequency. There are other unusual and obsolete FM broadcasting standards in some countries, with non-standard spacings of 1, 10, 30, 74, 500, and 300 kHz. To minimise inter-channel interference, stations operating from the same or nearby transmitter sites tend to keep to at least a 500 kHz frequency separation even when closer frequency spacing is technically permitted. The ITU publishes Protection Ratio graphs, which give
3321-518: The background noise for listeners, often at the expense of overall perceived sound quality. In such instances, however, this technique is often surprisingly effective in increasing the station's useful range. The first radio station to broadcast in FM in Brazil was Rádio Imprensa, which began broadcasting in Rio de Janeiro in 1955, on the 102.1 MHz frequency, founded by businesswoman Anna Khoury. Due to
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3402-702: The call sign from WKIW , the K-LOVE station in Ironwood, Michigan . The Dittman family chose to retain WABB (1480 AM) and the rights to the "WABB" callsign; however, they would later sell WABB AM to Omni Broadcasting on October 24, 2012, with the new owners changing its call sign to WTKD, following the flip to sports talk . Another broadcaster, Big Fish Broadcasting, reserved the " WABB " call letters for their silent AM radio station in Belton, South Carolina . On July 9, 2012,
3483-402: The carrier, with its frequency remaining constant. With FM, frequency deviation from the assigned carrier frequency at any instant is directly proportional to the amplitude of the (audio) input signal, determining the instantaneous frequency of the transmitted signal. Because transmitted FM signals use significantly more bandwidth than AM signals, this form of modulation is commonly used with
3564-431: The country is one of the main advantages over DAB/+ radio . This is still less than the range of AM radio waves, which because of their lower frequencies can travel as ground waves or reflect off the ionosphere , so AM radio stations can be received at hundreds (sometimes thousands) of miles. This is a property of the carrier wave's typical frequency (and power), not its mode of modulation. The range of FM transmission
3645-567: The extension of the FM band to 108.0 MHz between 1980 and 1995, FM expanded rapidly throughout the British Isles and effectively took over from LW and MW as the delivery platform of choice for fixed and portable domestic and vehicle-based receivers. In addition, Ofcom (previously the Radio Authority) in the UK issues on demand Restricted Service Licences on FM and also on AM (MW) for short-term local-coverage broadcasting which
3726-582: The first time on February 5, 1973, with the song " Stuck Inside of Mobile with the Memphis Blues Again " by Bob Dylan (which was also the final song played on February 29, 2012). WABB-FM was originally a simulcast of its sister station before moving toward its long-running Top 40 format in 1984. Notable alumni of WABB include radio personalities Michael Scott Shannon and Leslie Fram . WABB's longtime owner, president, and general manager Bernie Dittman died on October 25, 2006, after suffering from
3807-513: The high import costs of FM radio receivers, transmissions were carried out in circuit closed to businesses and stores, which played ambient music offered by radio. Until 1976, Rádio Imprensa was the only station operating in FM in Brazil. From the second half of the 1970s onwards, FM radio stations began to become popular in Brazil, causing AM radio to gradually lose popularity. In 2021, the Brazilian Ministry of Communications expanded
3888-470: The higher ( VHF or UHF ) frequencies used by TV , the FM broadcast band , and land mobile radio systems . The maximum frequency deviation of the carrier is usually 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
3969-503: The import of vehicles, principally from the United States, with radios that can only tune to these frequencies. In some parts of Europe , Greenland , and Africa , only even multiples are used. In the United Kingdom , both odd and even are used. In Italy , multiples of 50 kHz are used. In most countries the maximum permitted frequency error of the unmodulated carrier is specified, which typically should be within 2 kHz of
4050-524: The late 1960s, FM had been adopted for broadcast of stereo "A.O.R.—' Album Oriented Rock ' Format", but it was not until 1978 that listenership to FM stations exceeded that of AM stations in North America. In most of the 70s FM was seen as highbrow radio associated with educational programming and classical music, which changed during the 1980s and 1990s when Top 40 music stations and later even country music stations largely abandoned AM for FM. Today AM
4131-411: The latter). Urban adult contemporary playlists generally consist of many different genres that originated amongst Black Americans including R&B , soul , funk , disco , jazz , pop , hip-hop , electro , quiet storm , gospel , new jack swing , and hip-hop soul . The format usually plays some classic R&B hits, as well as hits that are ten years old or more. Classic dance music also has
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#17327908954794212-527: 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 simultaneously transmitted using the same system of subcarrier modulation as part of
4293-568: The main channel signal-to-noise ratio. The GE and Zenith systems, so similar that they were considered theoretically identical, were formally approved by the FCC in April 1961 as the standard stereo FM broadcasting method in the United States and later adopted by most other countries. It is important that stereo broadcasts be compatible with mono receivers. For this reason, the left (L) and right (R) channels are algebraically encoded into sum (L+R) and difference (L−R) signals. A mono receiver will use just
4374-405: The minimum spacing between frequencies based on their relative strengths. Only broadcast stations with large enough geographic separations between their coverage areas can operate on the same or close frequencies. Frequency modulation or FM is a form of modulation which conveys information by varying the frequency of a carrier wave ; the older amplitude modulation or AM varies the amplitude of
4455-540: The next few years this station operated under the call signs W57A, W87A and WGFM, and moved to 99.5 MHz when the FM band was relocated to the 88–108 MHz portion of the radio spectrum. General Electric sold the station in the 1980s. Today this station is WRVE . Other pioneers included W2XQR/W59NY/WQXQ/WQXR-FM , New York; W47NV/WSM-FM Nashville, Tennessee (signed off in 1951); W1XER/W39B/WMNE , with studios in Boston and later Portland, Maine, but whose transmitter
4536-433: The originating station. The Crosby system was rejected by the FCC because it was incompatible with existing subsidiary communications authorization (SCA) services which used various subcarrier frequencies including 41 and 67 kHz. Many revenue-starved FM stations used SCAs for "storecasting" and other non-broadcast purposes. The Halstead system was rejected due to lack of high frequency stereo separation and reduction in
4617-532: The previous " K-LOVE " branded Christian radio format was a result of a multi-station deal that saw the programming formerly on WLVM move to WDLT-FM (98.3 FM), urban adult contemporary programming on WDLT-FM move to WABD (now WLVM , 104.1 FM), the contemporary hit radio format on WABD move to WLVM (now WABD, 97.5 FM). On July 16, 2012, this station's legal call sign was changed by the FCC from WLVM to WABD. The station originally had its roots in WABB (1480 AM). WABB began broadcasting on June 19, 1948, when it
4698-559: The reasons for this were: Public service broadcasters in Ireland and Australia were far slower at adopting FM radio than those in either North America or continental Europe . Hans Idzerda operated a broadcasting station, PCGG , at The Hague from 1919 to 1924, which employed narrow-band FM transmissions. In the United Kingdom the BBC conducted tests during the 1940s, then began FM broadcasting in 1955, with three national networks:
4779-456: The receiver also reduces the high-frequency noise. These processes of boosting and then 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
4860-521: The receiver to identify a stereo transmission and to regenerate the 38 kHz sub-carrier with the correct phase. The composite stereo multiplex signal contains the Main Channel (L+R), the pilot tone, and the (L−R) difference signal. This composite signal, along with any other sub-carriers, modulates the FM transmitter. The terms composite , multiplex and even MPX are used interchangeably to describe this signal. The instantaneous deviation of
4941-570: The required area is covered without causing interference to other stations further away. Practical transmitter powers range from a few milliwatts to 80 kW. As transmitter powers increase above a few kilowatts, the operating costs become high and only viable for large stations. The efficiency of larger transmitters is now better than 70% (AC power in to RF power out) for FM-only transmission. This compares to 50% before high efficiency switch-mode power supplies and LDMOS amplifiers were used. Efficiency drops dramatically if any digital HD Radio service
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#17327908954795022-400: The resulting signal is that it alternates between left and right at 38 kHz, with the phase determined by the 19 kHz pilot signal. Most stereo encoders use this switching technique to generate the 38 kHz subcarrier, but practical encoder designs need to incorporate circuitry to deal with the switching harmonics. Converting the multiplex signal back into left and right audio signals
5103-415: The separation as the signal-to-noise ratio worsens, eventually going to mono while still indicating a stereo signal is received. As with monaural transmission, it is normal practice to apply pre-emphasis to the left and right channels before encoding and to apply de-emphasis at the receiver after decoding. In the U.S. around 2010, using single-sideband modulation for the stereo subcarrier was proposed. It
5184-572: The station with the same song that launched 97.5, " Stuck Inside of Mobile with the Memphis Blues Again " by Bob Dylan , the station flipped to the K-LOVE Christian Contemporary format, thus ending WABB-FM's 39-year run as a Top 40/CHR. The format would not be lost in the area, as Cumulus relaunched the format at 104.1, with similar calls as WABD, at almost exactly the same time as WABB became K-Love. The station changed its call letters to WLVM on March 2, after EMF transferred
5265-610: The stations playing this music were on AM radio . Primary artists included The Isley Brothers , McFadden & Whitehead , Aretha Franklin , Marvin Gaye , and The Temptations . One of the first stations to try the format was WSID in Baltimore in the late 1950s/1960s/1970s. WDGS in the Louisville market had a full-range urban AC format, with no rap music, as early as 1985. WDGS neatly substituted jazz, blues and urban/soul gold for
5346-505: The term urban is outdated in that R&B and hip hop music have gained massive popularity outside the inner cities and the descriptor should not serve as a euphemism for "black music". He recommended substituting the terms adult R&B for the urban adult contemporary format and hip hop for urban contemporary . Myron Fears, operations manager and program director of the black owned Carter Broadcast Group in Kansas City, defended
5427-531: The top 25 U.S. radio markets to transmit in Quadraplex. The test results hopefully would prove to the FCC that the system was compatible with existing two-channel stereo transmission and reception and that it did not interfere with adjacent stations. There were several variations on this system submitted by GE, Zenith, RCA, and Denon for testing and consideration during the National Quadraphonic Radio Committee field trials for
5508-423: The transmitter carrier frequency due to the stereo audio and pilot tone (at 10% modulation) is where A and B are the pre-emphasized left and right audio signals and f p {\displaystyle f_{p}} =19 kHz is the frequency of the pilot tone. Slight variations in the peak deviation may occur in the presence of other subcarriers or because of local regulations. Another way to look at
5589-412: The use of the urban tag. Responding to Republic's elimination of the term, he expressed concern that the action diminishes the status of black music executives within record companies and the industry as a whole: I do not think it’s a great idea because it nullifies all the hard work that past African American music executives built. This potentially leads to the dissolving of people and positions within
5670-537: The use of two FM stations; one transmitting the front audio channels, the other the rear channels. A breakthrough came in 1970 when KIOI ( K-101 ) in San Francisco successfully transmitted true quadraphonic sound from a single FM station using the Quadraplex system under Special Temporary Authority from the FCC . Following this experiment, a long-term test period was proposed that would permit one FM station in each of
5751-629: The world, the FM broadcast band falls within the VHF part of the radio spectrum . Usually 87.5 to 108.0 MHz is used, or some portion of it, with few exceptions: The frequency of an FM broadcast station (more strictly its assigned nominal center frequency) is usually a multiple of 100 kHz. In most of South Korea , the Americas , the Philippines , and the Caribbean , only odd multiples are used. Some other countries follow this plan because of
5832-1099: The years 1967 to 1978, but also played songs from as far back as 1963 and as recent as the early 1980s. Included were both ballads and uptempo songs. WGCI even played songs from the 1950s, including Unforgettable by Nat King Cole , though Ross said even teenagers liked the station because they had learned about older songs from their parents, and because newer versions of old songs were being recorded. Other stations included WRBO 103.5 in Memphis, WNPL in Nashville, KMEZ in New Orleans and WPLZ in Richmond . In addition to WRBO, urban oldies stations include WATV (AM) in Birmingham, Alabama , and KAJM in Phoenix. Some urban oldies stations refer to this format as "old school," for example, WOSL in Cincinnati. There
5913-504: The years. Currently WABD has two full-time local personalities. Jimmy Steele (Program Director) hosts mid days and Twiggins hosts afternoons. Twiggins has been with WABD since 2015 but got his start at the original WABB. Mornings became syndicated from Melbourne, Florida in late 2016 by Tony Zazza and Cheree. The show is called "Zazza mornings with Cheree," and is broadcast in 3 markets (Melbourne, Florida; Fort Walton Beach, Florida; and Mobile, Alabama). FM broadcasting Throughout
5994-766: Was 27.5 kHz. The IF bandwidth was ±5 kHz, as the only goal at the time was to relay AM radio-quality audio. This transmission system used 75 μs audio pre-emphasis like the main monaural audio and subsequently the multiplexed stereo audio. In the late 1950s, several systems to add stereo to FM radio were considered by the FCC . Included were systems from 14 proponents including Crosby, Halstead, Electrical and Musical Industries, Ltd ( EMI ), Zenith, and General Electric. The individual systems were evaluated for their strengths and weaknesses during field tests in Uniontown, Pennsylvania , using KDKA-FM in Pittsburgh as
6075-497: Was also more popular than mainstream urban. "Urban oldies" refers to R&B music dating back to the late 1950s/early 1960s through the early 1990s. Although African Americans are the primary audience, radio stations playing this type of music often attract White listeners because R&B is one of the roots of rock and roll . A more mass-appeal version of the format is rhythmic oldies , which attracts both white and black listeners, as well as Latino listeners (particularly in
6156-616: Was atop the highest mountain in the northeast United States, Mount Washington , New Hampshire (shut down in 1948); and W9XAO/W55M/WTMJ-FM Milwaukee, Wisconsin (went off air in 1950). A commercial FM broadcasting band was formally established in the United States as of January 1, 1941, with the first fifteen construction permits announced on October 31, 1940. These stations primarily simulcast their AM sister stations, in addition to broadcasting lush orchestral music for stores and offices, classical music to an upmarket listenership in urban areas, and educational programming. On June 27, 1945
6237-517: Was owned by the Mobile Register under call letters meaning "We are Alabama's Best Broadcasters". WABB had an FM simulcast from the very beginning, starting with 107.9 MHz and later 102.1 MHz until it was discontinued in the 1950s. Shortly after owner Bernie Dittman moved to Mobile from his native Ohio to join his father J.W. at the station in 1959, Top-40 music became the new format. The modern WABB-FM (97.5 FM) signed on for
6318-565: Was seen as another service which licensees could use to create additional income. Use of SCAs was particularly popular in the US, but much less so elsewhere. Uses for such subcarriers include radio reading services for the blind , which became common and remain so, private data transmission services (for example sending stock market information to stockbrokers or stolen credit card number denial lists to stores, ) subscription commercial-free background music services for shops, paging ("beeper") services, alternative-language programming, and providing
6399-656: Was tested in Germany between July 1979 and December 1981 by IRT . It was based on the Telefunken High ;Com broadband compander system, but was never introduced commercially in FM broadcasting. Yet another system was the CX -based noise reduction system FMX implemented in some radio broadcasting stations in the United States in the 1980s. FM broadcasting has included subsidiary communications authorization (SCA) services capability since its inception, as it
6480-442: Was the availability of older records in remastered form. Hurricane Dave Smith of WJJJ in Pittsburgh, which had switched from smooth jazz , doubted the format would succeed on FM radio , but he believed listeners who enjoyed older songs were used to AM. Sean Ross of WGCI in Chicago believed the format could work either place, but stations that selected it would be those desiring something different. The satellite format focused on
6561-424: Was theorized to be more spectrum-efficient and to produce a 4 dB s/n improvement at the receiver, and it was claimed that multipath distortion would be reduced as well. A handful of radio stations around the country broadcast stereo in this way, under FCC experimental authority. It may not be compatible with very old receivers, but it is claimed that no difference can be heard with most newer receivers. At present,
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