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160-688: WKCR-FM (89.9 FM ) is a radio station licensed to New York, New York . The station is owned by Columbia University and serves the New York metropolitan area . Founded in 1941, the station traces its history back to 1908 with the first operations of the Columbia University Radio Club (CURC). In 1956, it became one of the first college radio stations to adopt FM broadcasting , which had been invented two decades earlier by Professor Edwin Howard Armstrong . The station

320-466: A call sign on the air to legally identify the operator or station. In some countries, the call sign assigned to the station must always be used, whereas in other countries, the call sign of either the operator or the station may be used. In certain jurisdictions, an operator may also select a "vanity" call sign although these must also conform to the issuing government's allocation and structure used for Amateur Radio call signs. Some jurisdictions require

480-639: A 23‑year‑old student, had begun frequenting and recording performances at Minton's Playhouse , where Monk was the house pianist, in 1940 after being introduced by bassist and vocalist Duke Groner . The 23 acetate disc recordings he made over 1941 constitute the earliest recordings ever made of Monk's playing. The broadcast recording was made by Newman and several CURC members on one afternoon, with Newman and another student alternating as master of ceremonies . Four sets were recorded featuring Monk, Don Byas , Joe Guy , Kenny Clarke , and Helen Humes , and were rushed back to Columbia and played on CURC in

640-399: A 500 kHz frequency separation even when closer frequency spacing is technically permitted. The ITU publishes Protection Ratio graphs, which give 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

800-456: A US citizen may operate under reciprocal agreements in Canada, but not a non-US citizen holding a US license. Many people start their involvement in amateur radio on social media or by finding a local club. Clubs often provide information about licensing, local operating practices, and technical advice. Newcomers also often study independently by purchasing books or other materials, sometimes with

960-484: A brief appearance to play a duet with Cale on the viola. The blues and jazz record label Oblivion Records was based at the WKCR studio from 1972 until 1976, when it ceased initial operations. The label was founded by staff member Fred Seibert , who would later go on to found MTV , along with Dick Pennington and folk musician Tom Pomposello . During his time at WKCR, Seibert recorded and published live performances made at

1120-441: A club or organization for a period of time before a higher class of license can be acquired. A reciprocal licensing agreement between two countries allows bearers of an amateur radio license in one country under certain conditions to legally operate an amateur radio station in the other country without having to obtain an amateur radio license from the country being visited, or the bearer of a valid license in one country can receive

1280-464: A club or organization generally requires that an individual with a current and valid amateur radio license who is in good standing with the telecommunications authority assumes responsibility for any operations conducted under the club license or club call sign. A few countries may issue special licenses to novices or beginners that do not assign the individual a call sign but instead require the newly licensed individual to operate from stations licensed to

1440-402: A fax program. The original subcarrier frequency used at KE2XCC 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

1600-619: A fee to obtain such a vanity call sign; in others, such as the UK, a fee is not required and the vanity call sign may be selected when the license is applied for. The FCC in the U.S. discontinued its fee for vanity call sign applications in September 2015, but replaced it as $ 35 in 2022. Call sign structure as prescribed by the ITU consists of three parts which break down as follows, using the call sign ZS1NAT as an example: Many countries do not follow

1760-561: A given period of time. In addition to contests, a number of amateur radio operating award schemes exist, sometimes suffixed with "on the Air", such as Summits on the Air , Islands on the Air, Worked All States and Jamboree on the Air . Amateur radio operators may also act as citizen scientists for propagation research and atmospheric science . Radio transmission permits are closely controlled by nations' governments because radio waves propagate beyond national boundaries, and therefore radio

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1920-464: A month. However, a day before the station was to install its new antenna, the Port Authority intervened, stating that the antenna was not built to withstand strong enough winds. Despite an earlier agreement that the Port Authority would cover the costs for any transmitter and antenna modification or replacement, when confronted by station officials, the Port Authority refused to pay, denying that

2080-520: A national licensing process and may instead require prospective amateur radio operators to take the licensing examinations of a foreign country. In countries with the largest numbers of amateur radio licensees, such as Japan, the United States, Thailand, Canada, and most of the countries in Europe, there are frequent license examinations opportunities in major cities. Granting a separate license to

2240-432: A nuisance. The use of "ham" meaning "amateurish or unskilled" survives today sparsely in other disciplines (e.g. "ham actor"). The amateur radio community subsequently began to reclaim the word as a label of pride, and by the mid-20th century it had lost its pejorative meaning. Although not an acronym or initialism, it is often written as "HAM" in capital letters. The many facets of amateur radio attract practitioners with

2400-472: A number after to indicate the political region; prefix CY indicates geographic islands. Prefix VA1 or VE1 is Nova Scotia , VA2 / VE2 is Quebec , VA3 / VE3 is Ontario , VA4 / VE4 is Manitoba , VA5 / VE5 is Saskatchewan , VA6 / VE6 is Alberta , VA7 / VE7 is British Columbia , VE8 is the Northwest Territories , VE9 is New Brunswick , VY0

2560-450: A platform for music that was neglected by commercial radio, adopting the slogan "The Alternative". In a time when most Latin programming focused on older music and romantic ballads, it became one of the first stations in the United States to broadcast salsa . It also welcomed experimental and contemporary classical music , featuring musicians including Karlheinz Stockhausen , John Zorn , Zeena Parkins , and John Cage , who, in 1987, used

2720-409: A pool of at least 350. To pass, 26 of the 35 questions must be answered correctly. The Extra Class exam has 50 multiple choice questions (drawn randomly from a pool of at least 500), 37 of which must be answered correctly. The tests cover regulations, customs, and technical knowledge, such as FCC provisions, operating practices, advanced electronics theory, radio equipment design, and safety. Morse Code

2880-557: 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

3040-436: A separate license and a call sign in another country, both of which have a mutually-agreed reciprocal licensing approvals. Reciprocal licensing requirements vary from country to country. Some countries have bilateral or multilateral reciprocal operating agreements allowing hams to operate within their borders with a single set of requirements. Some countries lack reciprocal licensing systems. Others use international bodies such as

3200-400: A show focusing on Charlie Parker that he started in 1981 and hosted every weekday for about forty years. The New Yorker described Bird Flight as "plac[ing] a degree of attention on the music of the bebop saxophonist Charlie Parker that is so obsessive, so ardent and detailed, that Schaap frequently sounds like a mad Talmudic scholar who has decided that the laws of humankind reside not in

3360-877: A single artist's recorded work, in addition to interviews and educational programming. Festival broadcasts generally last 150 hours or longer, and the longest festivals have included the 2000 Louis Armstrong Centennial Festival Part I, which lasted for 184 hours non-stop from June 30 to July 7, and the 1999 Duke Ellington Centennial Festival, which lasted for 240 hours from April 23 to May 1. Musicians that have participated live in their own festivals include Ornette Coleman (February 1975), Roy Eldridge (January 1978), Sonny Rollins (March 1978), Cecil Taylor (March 1979), Max Roach (March 1981), Steve Lacy (November 1981), Benny Carter (August 1982), Eddie Durham (Summer 1986), Sun Ra (April 1987), Dizzy Gillespie (May 1987), Art Blakey (November 1989), Lionel Hampton (May 1990), and Don Cherry (May 1992). In one notable incident, during

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3520-417: A stereo/mono switch to allow listening in mono when reception conditions are less than ideal, and most car radios are arranged to reduce 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

3680-551: A wide range of interests. Many amateurs begin with a fascination with radio communication and then combine other personal interests to make pursuit of the hobby rewarding. Some of the focal areas amateurs pursue include radio contesting , radio propagation study, public service communication , technical experimentation , and computer networking . Hobbyist radio enthusiasts employ a variety of transmission methods for interaction . The primary modes for vocal communications are frequency modulation (FM) and single sideband (SSB). FM

3840-717: A year in the national capital and can be inordinately bureaucratic (for example in India) or challenging because some amateurs must undergo difficult security approval (as in Iran ). Currently, only Yemen and North Korea do not issue amateur radio licenses to their citizens. Some developing countries, especially those in Africa, Asia, and Latin America , require the payment of annual license fees that can be prohibitively expensive for most of their citizens. A few small countries may not have

4000-411: Is Nunavut , VY1 is Yukon , VY2 is Prince Edward Island , VO1 is Newfoundland , and VO2 is Labrador . CY is for amateurs operating from Sable Island (CY0) or St. Paul Island (CY9). Special permission is required to access either of these: from Parks Canada for Sable and Coast Guard for St. Paul. The last two or three letters of the call signs are typically the operator's choice (upon completing

4160-408: 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 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

4320-525: 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

4480-401: 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 the use of two FM stations; one transmitting the front audio channels, the other

4640-422: 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

4800-515: Is claimed that no difference can be heard with most newer receivers. At present, 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

4960-508: 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 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

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5120-596: 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 ,

5280-644: Is established by the International Telecommunication Union (ITU) through the Radio Regulations . National governments regulate technical and operational characteristics of transmissions and issue individual station licenses with a unique identifying call sign , which must be used in all transmissions. Amateur operators must hold an amateur radio license which is obtained by passing a government test demonstrating adequate technical radio knowledge and legal knowledge of

5440-604: Is in the Turks and Caicos Islands, VP6xxx is on Pitcairn Island, VP8xxx is in the Falklands, and VP9xxx is in Bermuda. Online callbooks or call sign databases can be browsed or searched to find out who holds a specific call sign. An example of an online callbook is QRZ.com . Non-exhaustive lists of famous people who hold or have held amateur radio call signs have also been compiled and published. Many jurisdictions (but not in

5600-429: 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, 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

5760-480: 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

5920-671: 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

6080-471: Is no longer tested in the U.S. Once the exam is passed, the FCC issues an Amateur Radio license which is valid for ten years. Studying for the exam is made easier because the entire question pools for all license classes are posted in advance. The question pools are updated every four years by the National Conference of VECs. Prospective amateur radio operators are examined on understanding of

6240-466: Is of international concern. Both the requirements for and privileges granted to a licensee vary from country to country, but generally follow the international regulations and standards established by the International Telecommunication Union and World Radio Conferences . All countries that license citizens to use amateur radio require operators to display knowledge and understanding of key concepts, usually by passing an exam. The licenses grant hams

6400-496: 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

6560-469: 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. Amateur radio Amateur radio , also known as ham radio , is the use of the radio frequency spectrum for purposes of non-commercial exchange of messages, wireless experimentation, self-training, private recreation, radiosport , contesting , and emergency communications . The term "amateur"

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6720-522: Is recognized for its superior audio quality, whereas SSB is more efficient for long-range communication under limited bandwidth conditions. Radiotelegraphy using Morse code , also known as "CW" from " continuous wave ", is the wireless extension of landline (wired) telegraphy developed by Samuel Morse and dates to the earliest days of radio. Although computer-based (digital) modes and methods have largely replaced CW for commercial and military applications, many amateur radio operators still enjoy using

6880-508: 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

7040-419: Is similar to Voice over IP (VoIP), but augments two-way radio communications rather than telephone calls. EchoLink using VoIP technology has enabled amateurs to communicate through local Internet-connected repeaters and radio nodes, while IRLP has allowed the linking of repeaters to provide greater coverage area. Automatic link establishment (ALE) has enabled continuous amateur radio networks to operate on

7200-630: 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

7360-692: Is the Wireless Institute of Australia , formed in 1910; other notable societies are the Radio Society of Great Britain , the American Radio Relay League , Radio Amateurs of Canada , Bangladesh NGOs Network for Radio and Communication , the New Zealand Association of Radio Transmitters and South African Radio League . ( See Category:Amateur radio organizations ) An amateur radio operator uses

7520-402: 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 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

7680-684: Is typically found in the 70 cm (420–450 MHz) wavelength range, though there is also limited use on 33 cm (902–928 MHz), 23 cm (1240–1300 MHz) and shorter. These requirements also effectively limit the signal range to between 20 and 60 miles (30–100 km). Linked repeater systems, however, can allow transmissions of VHF and higher frequencies across hundreds of miles. Repeaters are usually located on heights of land or on tall structures, and allow operators to communicate over hundreds of miles using hand-held or mobile transceivers . Repeaters can also be linked together by using other amateur radio bands , landline , or

7840-456: Is used to specify "a duly authorized person interested in radioelectric practice with a purely personal aim and without pecuniary interest" (either direct monetary or other similar reward); and to differentiate it from commercial broadcasting , public safety (such as police and fire), or professional two-way radio services (such as maritime, aviation, taxis, etc.). The amateur radio service ( amateur service and amateur-satellite service )

8000-619: Is valid only in the country where it is issued or in another country that has a reciprocal licensing agreement with the issuing country. In some countries, an amateur radio license is necessary in order to purchase or possess amateur radio equipment. Amateur radio licensing in the United States exemplifies the way in which some countries award different levels of amateur radio licenses based on technical knowledge: three sequential levels of licensing exams (Technician Class, General Class, and Amateur Extra Class) are currently offered, which allow operators who pass them access to larger portions of

8160-673: The Columbia University protests of 1968 , WKCR was the only source of live news from the university. With 50 or 60 students working in shifts, it was able to provide near-nonstop coverage for the week of protests. During the protests, the station had several "special operations" groups—student experts on telephone systems, key collectors who were able to open every lock on campus, and experts in acquiring telephone equipment that, according to station engineer Jon Perelstein, "a college radio station probably shouldn't have had"—which, by breaking into telephone distribution panel rooms through

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8320-975: The DuMont Building on Madison Avenue . Following a decade of bureaucratic struggle against the Port Authority of New York and New Jersey and the Federal Communications Commission , it began transmitting from an antenna atop the World Trade Center in 1985. After the towers' destruction in 2001, the station broadcast for a brief period of time from a backup transmitter on the roof of Carman Hall , before moving to 4 Times Square in 2003, where it remains today. Its studios are currently located in Alfred Lerner Hall . The first recorded instance of radio experimentation at Columbia took place in 1906, in

8480-831: 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 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

8640-724: The Internet . Amateur radio satellites can be accessed, some using a hand-held transceiver ( HT ), even, at times, using the factory "rubber duck" antenna. Hams also use the moon , the aurora borealis , and the ionized trails of meteors as reflectors of radio waves. Hams can also contact the International Space Station (ISS) because many astronauts are licensed as amateur radio operators. Amateur radio operators use their amateur radio station to make contacts with individual hams as well as participate in round-table discussion groups or "rag chew sessions" on

8800-548: The Internet . Amateur radio is officially represented and coordinated by the International Amateur Radio Union (IARU), which is organized in three regions and has as its members the national amateur radio societies which exist in most countries. According to an estimate made in 2011 by the American Radio Relay League (the American national amateur radio society), two million people throughout

8960-547: 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

9120-555: The Manhattan Municipal Building due to the attacks. WKCR had been planning on moving to Lerner Hall from its temporary studio in Riverside Church before the attacks. In 2011, The New York Times reported that it was considering a move back to the World Trade Center . The station was fined $ 10,000 in 2012 due to a lapse in its record-keeping from 2001 to 2006, which WKCR directors attributed to

9280-483: The SS Miramar . In February 1956, Columbia University applied for a construction permit for a new 10-watt station on 89.9 MHz. The FCC approved on April 5, and the first tests of the new station were carried out on May 14; full-time programming did not begin until October 8 for New York's third noncommercial radio outlet. It used a ten‑watt transmitter that once belonged to Armstrong, which it installed on

9440-440: 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 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

9600-482: The high frequency bands with global coverage. Other modes, such as FSK441 using software such as WSJT , are used for weak signal modes including meteor scatter and moonbounce communications. Fast scan amateur television has gained popularity as hobbyists adapt inexpensive consumer video electronics like camcorders and video cards in PCs . Because of the wide bandwidth and stable signals required, amateur television

9760-679: 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

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9920-686: The Amateur Radio spectrum and more desirable (shorter) call signs. An exam, authorized by the Federal Communications Commission (FCC), is required for all levels of the Amateur Radio license. These exams are administered by Volunteer Examiners, accredited by the FCC-recognized Volunteer Examiner Coordinator (VEC) system. The Technician Class and General Class exams consist of 35 multiple-choice questions, drawn randomly from

10080-625: The Americas , the Philippines , and the Caribbean , only odd multiples are used. Some other countries follow this plan because of 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

10240-524: The CW mode—particularly on the shortwave bands and for experimental work, such as Earth–Moon–Earth communication , because of its inherent signal-to-noise ratio advantages. Morse, using internationally agreed message encodings such as the Q code , enables communication between amateurs who speak different languages. It is also popular with homebrewers and in particular with "QRP" or very-low-power enthusiasts, as CW-only transmitters are simpler to construct, and

10400-665: 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

10560-496: 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 the FCC. The original Dorren Quadraplex System outperformed all

10720-520: 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

10880-979: 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

11040-399: The FM transmitter. The terms composite , multiplex and even MPX are used interchangeably to describe this signal. The instantaneous deviation of 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

11200-670: The Harvard Wireless Club (W1AF) and the MIT Radio Society (W1MX), it is the oldest amateur radio society. It set up its first experimental station on the roof of University Hall, where Uris Hall now stands, in November of that year with the blessings of Professor Mihajlo Pupin , who donated a corner of his laboratory in Havemeyer Hall to the club, as well a large electromagnetic coil . Originally intended only for catching stray signals from passing ships,

11360-653: The ITU convention for the numeral. In the United Kingdom the original calls G0xxx, G2xxx, G3xxx, G4xxx, were Full (A) License holders along with the last M0xxx full call signs issued by the City & Guilds examination authority in December 2003. Additional Full Licenses were originally granted to (B) Licenses with G1xxx, G6xxx, G7xxx, G8xxx and 1991 onward with M1xxx call signs. The newer three-level Intermediate License holders are assigned 2E0xxx and 2E1xxx, and

11520-503: The Isle of Man, "GJ" & "MJ" are Jersey and "GU" & "MU" are Guernsey. Intermediate licence call signs are slightly different. They begin 2#0 and 2#1 where the # is replaced with the country letters as above. For example "2M0" and "2M1" are Scotland, "2W0" and "2W1" are Wales and so on. The exception however is for England. The letter "E" is used, but only in intermediate-level call signs. For example "2E0" & "2E1" are used whereas

11680-529: The March 1976 festival dedicated to Thelonious Monk, a guest expert was explaining how Monk was able to create extraordinary music by playing "wrong notes" on the piano. Monk, who by this point had become a recluse, called the station and instructed them to "tell the guy on the air, 'The piano ain't got no wrong notes' ", before hanging up. WKCR annually celebrates the birthdays of prominent jazz musicians, including Monk, Louis Armstrong, and Charlie Parker, by playing

11840-590: The NBC Radio Network, were simultaneously 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 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

12000-461: The Organization of American States to facilitate licensing reciprocity. When traveling abroad, visiting amateur operators must follow the rules of the country in which they wish to operate. Some countries have reciprocal international operating agreements allowing hams from other countries to operate within their borders with just their home country license. Other host countries require that

12160-581: The RF spectrum, usually allowing choice of an effective frequency for communications across a local, regional, or worldwide path. The shortwave bands, or HF , are suitable for worldwide communication, and the VHF and UHF bands normally provide local or regional communication, while the microwave bands have enough space, or bandwidth , for amateur television transmissions and high-speed computer networks . In most countries, an amateur radio license grants permission to

12320-541: The Twin Towers. The move was delayed once more until 1981, due to a legal dispute with an unnamed New York‑based station over transmitter interference. WKCR's Madison Avenue transmitter continued to deteriorate until it finally broke down on July 17, 1981. By then, the World Trade Center antenna had already been installed, though the station's FCC permit to finally move had recently expired while it

12480-428: The UK & Europe) may issue specialty vehicle registration plates to licensed amateur radio operators. The fees for application and renewal are usually less than the standard rate for specialty plates. In most administrations, unlike other RF spectrum users, radio amateurs may build or modify transmitting equipment for their own use within the amateur spectrum without the need to obtain government certification of

12640-552: The United Kingdom and Australia, have begun requiring a practical assessment in addition to the written exams in order to obtain a beginner's license, which they call a Foundation License. In most countries, an operator will be assigned a call sign with their license. In some countries, a separate "station license" is required for any station used by an amateur radio operator. Amateur radio licenses may also be granted to organizations or clubs. In some countries, hams were allowed to operate only club stations. An amateur radio license

12800-399: The United States and became the first North American radio station to rebroadcast this signal. The next morning, two FBI agents walked into the station and confiscated the tape. A Freedom of Information Act request was filed on June 28, 2018, requesting the declassification of all documents related to the confiscation of the tapes and their whereabouts. The request was rejected on account of

12960-638: The United States, having been involved in the New York jazz scene from its founding; one of its first broadcasts was the earliest performance by Thelonious Monk on radio. Through The Stretch Armstrong and Bobbito Show , it has played an instrumental role in the development of hip hop since the 1990s. It was also one of the first stations in the United States to broadcast salsa music . The station made its first AM broadcast out of John Jay Hall and its first FM broadcast from Philosophy Hall , where Armstrong had invented FM. In 1958, it moved its transmitter to

13120-647: The WKCR studios once to remix opera music . During a May 29, 1978, minimalist music marathon hosted by staff member Tim Page , the station presented the radio premiers of several leading minimalist compositions, including Einstein on the Beach by Philip Glass and Music for 18 Musicians by Steve Reich . Page also organized a WKCR charity concert which was held on April 1, 1979, in Carnegie Hall , and featured Glass and Reich, in addition to John Cale , Leroy Jenkins , and Ursula Oppens . David Bowie also made

13280-677: The Wireless Club was known as the Columbia University Radio Club (CURC). The CURC made its first broadcasts with its ham radio station , W2AEE. The call sign was assigned to the CURC as early as 1931 and still operates under the Columbia University Amateur Radio Club. Its first recorded broadcast was in 1933, and the station received its license in 1938. In 1933, FM broadcasting was invented by Professor of Electrical Engineering Edwin Howard Armstrong in

13440-534: The agreement was ever made in the first place. A new antenna, built to the Port Authority's specifications, was constructed in September 1978, and the Port Authority announced that it would grant the station its approval again in a few weeks. In January 1979, WKCR received a $ 43,912 grant from the Office of Education of the United States Department of Health and Human Services to aid in its move to

13600-763: The air. Some join in regularly scheduled on-air meetings with other amateur radio operators, called " nets " (as in "networks"), which are moderated by a station referred to as "Net Control". Nets can allow operators to learn procedures for emergencies, be an informal round table, or cover specific interests shared by a group. Amateur radio operators, using battery- or generator-powered equipment, often provide essential communications services when regular channels are unavailable due to natural disaster or other disruptive events . Many amateur radio operators participate in radio contests, during which an individual or team of operators typically seek to contact and exchange information with as many other amateur radio stations as possible in

13760-461: The ancient Babylonian tractates but in alternate takes of ' Moose the Mooche ' and ' Swedish Schnapps .' " The red Naugahyde armchair for visitors in the WKCR studio is named the " Dizzy Gillespie chair", after the trumpeter sat there during an hours-long conversation with Schaap. Beginning in 1970, WKCR has held several jazz festivals a year, each one focusing on the presentation of the entirety of

13920-518: 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

14080-404: The basement of Philosophy Hall . As an undergraduate at Columbia, he had studied under Pupin and invented the regenerative circuit . Immediately after his graduation in 1913, he was offered a position at the university, and continued his experimentation with radios. In 1914, he strung up another antenna between Havemeyer and Schermerhorn Halls for a new radio. At the time, it was considered "one of

14240-513: The basic Foundation License holders are granted call signs M3xxx, M6xxx or M7xxx. Instead of using numbers, in the UK the second letter after the initial 'G' or 'M' identifies the station's location; for example, a call sign G7OOE becomes GM7OOE and M0RDM becomes MM0RDM when that license holder is operating a station in Scotland. Prefix "GM" & "MM" are Scotland, "GW" & "MW" are Wales, "GI" & "MI" are Northern Ireland, "GD" & "MD" are

14400-471: The best on the eastern coast", and could reportedly receive signals from as far away as Honolulu , Hawaii. Following his invention of FM, Armstrong created W2XMN , the first regularly operated FM radio station, which made its first broadcast on July 18, 1939. Soon after its completion, the CURC began using W2XMN to test the potential of FM for college radio. The CURC made its first public and FM broadcasts on W2XMN, for which it provided programming. WKCR proper

14560-446: The call signs beginning G or M for foundation and full licenses never use the "E". In the United States, for non-vanity licenses, the numeral indicates the geographical district the holder resided in when the license was first issued. Prior to 1978, US hams were required to obtain a new call sign if they moved out of their geographic district. In Canada, call signs start with VA, VE, VY, VO, and CY. Call signs starting with 'V' end with

14720-501: The classroom to teach English, map skills, geography, math, science, and computer skills. The term "ham" was first a pejorative term used in professional wired telegraphy during the 19th century, to mock operators with poor Morse code -sending skills (" ham-fisted "). This term continued to be used after the invention of radio and the proliferation of amateur experimentation with wireless telegraphy; among land- and sea-based professional radio operators, "ham" amateurs were considered

14880-431: 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

15040-764: The early 20th century. The First Annual Official Wireless Blue Book of the Wireless Association of America , produced in 1909, contains a list of amateur radio stations. This radio callbook lists wireless telegraph stations in Canada and the United States, including 89 amateur radio stations. As with radio in general, amateur radio was associated with various amateur experimenters and hobbyists. Amateur radio enthusiasts have significantly contributed to science , engineering , industry, and social services . Research by amateur operators has founded new industries, built economies, empowered nations, and saved lives in times of emergency. Ham radio can also be used in

15200-546: The entire catalogue of the artist's work in one broadcast. The station also holds jazz marathons on prominent death anniversaries and other special occasions, such as the beginning of a concert series featuring the Association for the Advancement of Creative Musicians held at Columbia, which the station celebrated with a 90‑hour broadcast starting on May 14, 1977, of the completed recorded works of every member of

15360-408: The equipment. Licensed amateurs can also use any frequency in their bands (rather than being allocated fixed frequencies or channels) and can operate medium-to-high-powered equipment on a wide range of frequencies so long as they meet certain technical parameters including occupied bandwidth, power, and prevention of spurious emission . Radio amateurs have access to frequency allocations throughout

15520-408: The evening. The recordings were later released as Midnight at Minton's in 1973. In a review, WEMU broadcaster Michael G. Nastos described the recordings as "priceless, the document of a transitional period from swing to bop". WKCR made the first stereo live broadcast of jazz music in 1960. The performance was by Red Allen 's band, in which J. C. Higginbotham was the trombonist at the time, and

15680-567: 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

15840-413: The first station to transmit from the World Trade Center. A nine-day, 200-hour long Louis Armstrong festival was planned to inaugurate the station's new transmitter. The move was delayed again when the Port Authority declared two of the application forms to be incomplete. The applications were resubmitted, and in November, the Port Authority announced that the station would be able to make the move within

16000-481: The formula below, is also generated. The pilot is transmitted at 8–10% of overall modulation level and used by 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

16160-482: 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 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

16320-423: The help of a mentor, teacher, or friend. In North America, established amateurs who help newcomers are often referred to as "Elmers", as coined by Rodney Newkirk, W9BRD, within the ham community. In addition, many countries have national amateur radio societies which encourage newcomers and work with government communications regulation authorities for the benefit of all radio amateurs. The oldest of these societies

16480-513: 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

16640-598: The host government's radio regulations. Radio amateurs are limited to a specific set of frequency bands, the amateur radio bands, allocated throughout the radio spectrum , but within these bands are allowed to transmit on any frequency using a variety of voice, text, image, and data communications modes. This enables communication across a city, region, country, continent, the world, or even into space. In many countries, amateur radio operators may also send, receive, or relay radio communications between computers or transceivers connected to secure virtual private networks on

16800-822: The human ear-brain signal processing system can pull weak CW signals out of the noise where voice signals would be totally inaudible. A similar "legacy" mode popular with home constructors is amplitude modulation (AM), pursued by many vintage amateur radio enthusiasts and aficionados of vacuum tube technology. Demonstrating a proficiency in Morse code was for many years a requirement to obtain an amateur license to transmit on frequencies below 30 MHz. Following changes in international regulations in 2003, countries are no longer required to demand proficiency. The United States Federal Communications Commission , for example, phased out this requirement for all license classes on 23 February 2007. Modern personal computers have encouraged

16960-417: The incident was uploaded to 4chan in 2013. FM broadcasting Throughout 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 ,

17120-570: The key concepts of electronics, radio equipment, antennas, radio propagation , RF safety, and the radio regulations of the government granting the license. These examinations are sets of questions typically posed in either a short answer or multiple-choice format. Examinations can be administered by bureaucrats , non-paid certified examiners, or previously licensed amateur radio operators. The ease with which an individual can acquire an amateur radio license varies from country to country. In some countries, examinations may be offered only once or twice

17280-524: 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

17440-501: 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 was tested in Germany between July 1979 and December 1981 by IRT . It

17600-465: 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 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

17760-417: The license holder to own, modify, and operate equipment that is not certified by a governmental regulatory agency. This encourages amateur radio operators to experiment with home-constructed or modified equipment. The use of such equipment must still satisfy national and international standards on spurious emissions . Amateur radio operators are encouraged both by regulations and tradition of respectful use of

17920-585: The licensing test, the ham writes three most-preferred options). Two-letter call sign suffixes require a ham to have already been licensed for 5 years. Call signs in Canada can be requested with a fee. Also, for smaller geopolitical entities, the numeral may be part of the country identification. For example, VP2xxx is in the British West Indies, which is subdivided into VP2Exx Anguilla, VP2Mxx Montserrat, and VP2Vxx British Virgin Islands. VP5xxx

18080-480: 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 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

18240-427: The maximum permitted frequency error of the unmodulated carrier is specified, which typically should be within 2 kHz of 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

18400-474: 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 (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

18560-513: The name CURC, the station made its unofficial debut on December 31, 1940, with a broadcast of audio from a New Year's Eve party in John Jay Dining Hall. Its official maiden broadcast was made on February 24, 1941, and opened with a recording of " Roar, Lion, Roar ", followed by light classical music, a 15‑minute sports show, 40 minutes of jazz, a campus news summary, and symphonic music. The station soon moved its headquarters to

18720-555: The news department would travel to Washington, D.C. annually to interview political figures, while WKCR became the only station in the New York area to carry United Nations General Assembly meetings in full. While the station's musical programming mainly focused on classical, it also played jazz, folk, bluegrass, and show tunes . Guests who were interviewed on the station during this time period included Martin Luther King Jr. , William F. Buckley Jr. , and Jimmy Hoffa . During

18880-540: 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

19040-399: The next sixteen years. From 1990 to 1998, WKCR broadcast The Stretch Armstrong and Bobbito Show , hosted by DJ Stretch Armstrong and Bobbito Garcia . The show served as an alternative to commercial hip hop radio, airing mostly obscure, unsigned artists, a number of whom would later dominate the hip hop scene in the late 1990s and early 2000s. The show has been credited with introducing

19200-403: The organization. Poet and critic Molly McQuade has praised WKCR's jazz programming, stating that "WKCR's inspired programming feels more like dream logic than traditional radio" and that she is "willingly indebted and harmlessly addicted" to several of the station's programs. When Sputnik 1 was launched on October 4, 1957, WKCR staff recorded its signal during the satellite's first pass over

19360-570: 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 the 1970s and 1980s: A commercially unsuccessful noise reduction system used with FM radio in some countries during

19520-451: The phone on the next desk over and continued his report. Station staff also tapped a New York City Police Department phone line that ran from a university telephone distribution panel to a command vehicle outside, and, on radios loaned from W2AEE, stalked frequencies known to be used by the NYPD when planning large operations. I'm in a room on the seventh floor [of Hartley Hall ] overlooking

19680-892: The privilege to operate in larger segments of the radio frequency spectrum, with a wider variety of communication techniques, and with higher power levels relative to unlicensed personal radio services (such as CB radio , FRS , and PMR446 ), which require type-approved equipment restricted in mode, range, and power. Amateur licensing is a routine civil administrative matter in many countries. Amateurs therein must pass an examination to demonstrate technical knowledge, operating competence, and awareness of legal and regulatory requirements, in order to avoid interfering with other amateurs and other radio services. A series of exams are often available, each progressively more challenging and granting more privileges: greater frequency availability, higher power output, permitted experimentation, and, in some countries, distinctive call signs. Some countries, such as

19840-419: The protests, they were interviewed on WKCR. Following the station's involvement in the protests, the university administration has treated the station with animosity. After 1968, WKCR sought to rid itself of its reputation as a "classroom of the air". The AM carrier current service was discontinued, while the FM station shifted its emphasis from education to music, particularly jazz. The station sought to provide

20000-507: 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 the top 25 U.S. radio markets to transmit in Quadraplex. The test results hopefully would prove to

20160-559: 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:

20320-478: The receiver after decoding. In the U.S. around 2010, using single-sideband modulation for the stereo subcarrier was proposed. It 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

20480-428: The records having been destroyed in 1975. WKCR was allegedly hijacked mid-broadcast once around 1995. The interruption reportedly began with eerie screeches and was followed by silence, then by a woman reciting obituaries, including those of Frank Oppenheimer and several victims of the 1988 bombing of Pan Am Flight 103 . After a couple of minutes, the station took control and came back on air as usual. A recording of

20640-570: 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

20800-440: The roof of Philosophy Hall, as well as $ 25,000 worth of master control equipment donated by WMCA . A third of the student volunteers for WKCR-FM were women from the affiliated Barnard College . Until the 1970s, the carrier current WKCR, focused largely on music broadcasting and restricted to campus, coexisted with WKCR‑FM, which covered the entire New York metropolitan area with a greater emphasis on education. Programming

20960-527: The same year as the first AM radio transmission made by Reginald Fessenden . Records indicate that a Columbia University Experimental Wireless Station had set up a cage‑type radio antenna between the chimneys of Havemeyer Hall and Schermerhorn Hall . What is now WKCR‑FM originated as the Wireless Telegraph Club of Columbia University, now under the name Columbia University Amateur Radio Club. Founded in 1908, one year before

21120-474: The scene... Candles are being lit in various windows of Hamilton Hall ... There has been a lot of egg-throwing... The crowd is milling about... Someone is playing " The Marseillaise "... Roger Berkley on WKCR, reported in The New York Times WKCR coverage only stopped for a period of time on April 26, when the university ordered the station to suspend operations. Students demanded

21280-423: The space between Hartley Hall and Hamilton Hall . Within its first year, CURC was broadcasting 18 hours a day, including 10 + 1 ⁄ 2   hours of rebroadcasts from W71NY and W2XMN. After the FCC officially recognized college radio stations in 1946, the station received the official call sign of WKCR (standing for "King's Crown Radio"); the designation was originally used by a Merchant Marine ship,

21440-497: The spectrum to use as little power as possible to accomplish the communication. This is to minimise interference or EMC to any other device. Although allowable power levels are moderate by commercial standards, they are sufficient to enable global communication. Lower license classes usually have lower power limits; for example, the lowest license class in the UK (Foundation licence) has a limit of 10 W. Power limits vary from country to country and between license classes within

21600-497: The station be allowed to return to the air, and within half an hour the administration relented. The New York Times described WKCR's reporting as "clear and concise with a sound of informality and immediacy". The station contradicted the narratives offered by commercial news outlets, which only broadcast statements made by politicians and university administrators, by offering student perspectives to its audience. When civil rights activists H. Rap Brown and Stokely Carmichael joined

21760-673: The station broadcast from its backup transmitter atop Carman Hall . Its range was severely reduced, its signal barely reaching past a 20-mile radius until 2003, when the station was able to set up a new antenna at 4 Times Square , where it remains today. WKCR was one of four FM radio stations that transmitted from the World Trade Center at the time of its destruction, the others being WNYC-FM , WKTU , and WPAT-FM . For three weeks beginning on September 17, WKCR loaned its new studio in Lerner Hall to WNYC, which continued broadcasting over its AM adjunct but could not access its headquarters in

21920-419: The station started to heavily emphasize the genre, and has since hosted numerous prominent jazz musicians at its studio. By the 1990s, it had become one of the premier stations for jazz in the United States. As of 2022, about 40% of WKCR's airtime is dedicated to jazz. In June or July 1941, within five months of its official debut, CURC aired the first radio performance by pianist Thelonious Monk . Jerry Newman,

22080-429: The station suspended its regular programming to cover the pro-Palestinian campus occupation . Jazz has been a staple of WKCR's programming since its very founding, in part due to its proximity to Harlem , where bebop was developing during the 1940s. Its first broadcast as an official station with FCC approval began with "Swing is Here", a record with Gene Krupa and Roy Eldridge . After the 1968 protests at Columbia,

22240-629: The station was soon used to communicate with stations from other universities and other stations in New York City. It engaged in its first test with the Wireless Association at Princeton University in 1909, and in March of that year, it was used to receive the results of a basketball game against the University of Pennsylvania from The Bellevue-Stratford Hotel in Philadelphia , the first such use of radio by college students. By 1915,

22400-541: The station; notable albums that were recorded or edited at WKCR include Live in New York , featuring Mississippi Fred McDowell and Blues from the Apple , featuring Charles Walker and the New York City Blues Band. WKCR began making plans in 1975 to move its transmitter to 1 World Trade Center , citing deteriorating signal quality due to the construction of the nearby Citigroup Center . Fundraising

22560-462: The switching harmonics. Converting the multiplex signal back into left and right audio signals 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

22720-465: The transmitted signal. Because transmitted FM signals use significantly more bandwidth than AM signals, this form of modulation is commonly used with 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,

22880-422: The turmoil at the station after the 9/11 attacks. WKCR was one of several college radio stations which had been fined by the FCC in recent years, a practice that was criticized as punitive for its lack of distinction between commercial stations and those run by students, which are generally characterized by high turnover and lower budgets. The FCC's policy towards college stations was relaxed in 2013. In April 2024,

23040-426: The university tunnel system , were able to appropriate campus phone lines so that reporters could instantly communicate with station headquarters from any of the occupied buildings. According to one story, when the police stormed Low Memorial Library , a staff member picked up one of the phones and began reporting on the events. When a policeman came over and destroyed the phone he was using, the student simply picked up

23200-442: The use of digital modes such as radioteletype (RTTY) which previously required cumbersome mechanical equipment. Hams led the development of packet radio in the 1970s, which has employed protocols such as AX.25 and TCP/IP . Specialized digital modes such as PSK31 allow real-time, low-power communications on the shortwave bands but have been losing favor in place of newer digital modes such as FT8 . Radio over IP , or RoIP,

23360-509: The visiting ham apply for a formal permit, or even a new host country-issued license, in advance. The reciprocal recognition of licenses frequently not only depends on the involved licensing authorities, but also on the nationality of the bearer. As an example, in the US, foreign licenses are recognized only if the bearer does not have US citizenship and holds no US license (which may differ in terms of operating privileges and restrictions). Conversely,

23520-645: The world are regularly involved with amateur radio. About 830,000 amateur radio stations are located in IARU Region 2 (the Americas) followed by IARU Region 3 (South and East Asia and the Pacific Ocean) with about 750,000 stations. A significantly smaller number, about 400,000, are located in IARU Region 1 (Europe, Middle East, CIS , Africa). The origins of amateur radio can be traced to the late 19th century, but amateur radio as practised today began in

23680-525: The world to Biggie Smalls , Eminem , Jay-Z , Big L , Big Pun , Fat Joe , Wu Tang Clan , Mobb Deep , and the Fugees , among others. The Stretch Armstrong and Bobbito Show was voted the "best hip-hop show of all time" by The Source in 1998. WKCR's transmitter was destroyed on September 11, 2001, when a hijacked plane destroyed the North Tower of the World Trade Center . For the next two years,

23840-467: Was accused of failing to replace broken equipment, which had caused the station's frequency to creep up from 89.9 to 89.95 MHz. WKCR Manager Andy Caploe responded that the station could not have known whether there were any problems with the transmitter in the first place, because its testing equipment was also broken. The station finally made the move in April 1985, where it would continue broadcast from for

24000-616: 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

24160-530: 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

24320-404: Was broadcast from the university sundial . Spearheading WKCR's post-1968 transition into a jazz-oriented radio station was Phil Schaap , one of the foremost jazz experts of the late 20th century. He became a disc jockey at the station as a freshman in 1970, and continued to work there pro bono after his graduation until his death in 2021. He was most well known on the station for Bird Flight ,

24480-549: Was completed in September, and the station was given until March 31, 1976, to build its new transmitter. Due to a bureaucratic stalemate, the deadline was missed, and the station had to apply for a new lease. The Columbia Daily Spectator reported on September 14, 1976, that negotiations with the Port Authority of New York and New Jersey were in their final stages, and that the move was projected to take place before January 1, 1977. In July 1977, The New York Times announced that WKCR would move by September 15 of that year, and would

24640-506: Was dealing with a hum which had interfered with broadcasts for the past three weeks. The station began transmitting from the Twin Towers for the first time at 9:30   a.m. on July 20, though the broadcast was shut down after 45 minutes by the FCC, forcing WKCR to repair and continue to use its old antenna. In July 1982, the FCC fined the station $ 8,000 for violations of federal equipment and licensing regulation, which were discovered during an allegedly routine and random inspection. The station

24800-520: Was founded in 1940. The original station was built almost single‑handedly by electrical engineering student William Hutchins in his room in John Jay Hall . Armstrong donated a microphone and turntables to the fledgling station. While setting the station up, the Radio Club engaged in illegal experimentation, exceeding FCC minimum power regulations for carrier current transmission . Under

24960-502: Was largely university sports, lecture series, classical music, and broadcasts from the United Nations, including many interviews with representatives of foreign nations. WKCR‑FM began broadcasting from the DuMont Building on Madison Avenue in 1958, and in 1964 it became the first noncommercial radio station to broadcast in stereo. During the 1960s, the station would continue to develop its educational content. Members of

25120-473: Was preceded by student involvement in W2XMN , an experimental FM station founded by Armstrong, for which the CURC provided programming. Originally an education-focused station, since the Columbia University protests of 1968 , WKCR-FM has shifted its focus towards alternative musical programming, with an emphasis on jazz , classical, and hip-hop . WKCR has been described as one of the premier stations for jazz in

25280-457: Was rejected due to lack of high frequency stereo separation and reduction in 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,

25440-565: 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

25600-446: Was used in the earliest days of FM broadcasting. According to a BBC report from 1946, 100 μs was originally considered in 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

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