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Carrier Current
Carrier current transmission, originally called wired wireless, employs guided low-power Radio frequency, radio-frequency signals, which are transmitted along electrical conductors. The transmissions are picked up by receivers that are either connected to the conductors, or a short distance from them. Carrier current transmission is used to send audio and telemetry to selected locations, and also for low-power broadcasting that covers a small geographical area, such as a college campus. The most common form of carrier current uses longwave or medium wave Amplitude modulation, AM radio signals that are sent through existing electrical wiring, although other conductors can be used, such as telephone lines. Technology Carrier current generally uses low-power transmissions. In cases where the signals are being carried over electrical wires, special preparations must be made for distant transmissions, as the signals cannot pass through standard utility transformers. Signals can bridge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Frequency
Radio frequency (RF) is the oscillation rate of an alternating electric current or voltage or of a magnetic, electric or electromagnetic field or mechanical system in the frequency range from around to around . This is roughly between the upper limit of audio frequencies that humans can hear (though these are not electromagnetic) and the lower limit of infrared frequencies, and also encompasses the microwave range. These are the frequencies at which energy from an oscillating current can radiate off a conductor into space as radio waves, so they are used in radio technology, among other uses. Different sources specify different upper and lower bounds for the frequency range. Electric current Electric currents that oscillate at radio frequencies (RF currents) have special properties not shared by direct current or lower audio frequency alternating current, such as the 50 or 60 Hz current used in electrical power distribution. * Energy from RF currents in conduct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telephone Newspaper
Telephone Newspapers, introduced in the 1890s, transmitted news and entertainment to subscribers over telephone lines. They were the first example of electronic broadcasting, although only a few were established, most commonly in European cities. These systems predated the development, in the 1920s, of radio broadcasting. They were eventually supplanted by radio stations, because radio signals could more easily cover much wider areas with higher quality audio, without incurring the costs of a telephone line infrastructure. History The introduction of the telephone in the mid-1870s included numerous demonstrations of its use for transmitting musical concerts over various distances. In one particularly advanced example, Clément Ader prepared a listening room at the 1881 Paris Electrical Exhibition, where attendees could listen to performances, in stereo, from the Paris Grand Opera. The concept also appeared in Edward Bellamy's influential 1888 utopian novel, '' Looking Backwa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intercom
An intercom, also called an intercommunication device, intercommunicator, or interphone, is a stand-alone voice communications system for use within a building, small collection of buildings or portably within a small coverage area, which functions independently of the public telephone network. Intercoms are generally mounted permanently in buildings and vehicles, but can also be detachable and portable. Intercoms can incorporate connections to public address loudspeaker systems, walkie talkies, telephones, and other intercom systems. Some intercom systems incorporate control of devices such as signal lights and door latches. Intercoms are used on a wide variety of properties; from houses that only require one connection between a resident and the property's entrance to multi-unit apartments that require intercom hardware to be installed in every individual apartment. Some are equipped with video and its wiring (electrical installation) can be connected to the outside with a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
WBRU
WBRU is an internet radio station based in Providence, Rhode Island. The station is owned and operated by Brown Broadcasting Service, an independent Nonprofit organization, non-profit organization, and is primarily staffed by students from Brown University. Formerly an FM modern rock radio station that broadcast at 95.5 FM in the Rhode Island area, WBRU currently broadcasts two online stations with different genres on each: indie and alternative on WBRU and an urban contemporary format on WBRU360, named after its long-time Sunday program, ''The 360° Experience in Sound''. Since January 2018, WBRU's urban contemporary programming has been rebroadcast on Providence low-power FM station 101.1 FM, which is owned by another Brown University-affiliated group and has the call sign WBRU-LP. WBRU has its origins in The Brown Network, which was founded in 1936 as one of the earliest amateur college radio broadcasters. By the time that the Brown Broadcasting Service organization was found ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brown University
Brown University is a Private university, private Ivy League research university in Providence, Rhode Island, United States. It is the List of colonial colleges, seventh-oldest institution of higher education in the US, founded in 1764 as the ''College in the English Colony of Rhode Island and Providence Plantations''. One of nine colonial colleges chartered before the American Revolution, it was the first US college to codify that admission and instruction of students was to be equal regardless of the religious affiliation of students. The university is home to the oldest applied mathematics program in the country and oldest engineering program in the Ivy League. It was one of the early doctoral-granting institutions in the U.S., adding masters and doctoral studies in 1887. In 1969, it adopted its Open Curriculum (Brown University), Open Curriculum after student lobbying, which eliminated mandatory Curriculum#Core curriculum, general education distribution requirements. In 197 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High School Radio
High school radio are radio stations located at high schools and usually operated by its students with faculty supervision. The oldest extant high school AM radio station is AM 1450 KBPS in Portland, Oregon. Portland radio station KBPS, first licensed in 1923, is the second oldest radio station overall in the city of Portland. The student body of Benson Polytechnic High School purchased the transmitter and other equipment from Stubbs Electric in Portland for $1,800. Money for the purchase of the station came from student body funds. On March 23, 1923, the student body of Benson was licensed by the federal government to operate a radio station using 200 watts of power on 834 kilocycles. The first call letters of the station were KFIF. The station made its formal debut on the air and was officially dedicated in early May 1923, between the hours of 9:30 p.m. to 10:30 p.m., on the opening night of the 5th annual Benson Tech Show. In spring of 1930, the callsign changed from KFIF to K ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Campus Radio
Campus radio (also known as college radio, university radio or student radio) is a type of radio station that is run by the students of a college, university or other educational institution. Programming may be exclusively created or produced by students, or may include program contributions from the local community in which the radio station is based. Sometimes campus radio stations are operated for the purpose of training professional radio personnel, sometimes with the aim of broadcasting educational programming, while other radio stations exist to provide alternative to commercial broadcasting or government broadcasters. Campus radio stations are generally licensed and regulated by national governments, and have very different characteristics from one country to the next. One commonality between many radio stations regardless of their physical location is a willingness—or, in some countries, even a licensing requirement—to broadcast musical selections that are not categ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio SRF 1
Radio SRF 1 is a Swiss radio channel, one of six operated by Schweizer Radio und Fernsehen (SRF), with its headquarters in Zürich. It was launched in 1931 as Radio Beromünster (named after the Beromünster municipality on which its original transmission tower was located) and was the first German-language radio station for German-speaking Switzerland. Programmes The channel is receivable throughout Switzerland via DAB, cable, satellite and the internet. Until the end of 2024 the channel also broadcast on FM. Programming is mainly general and includes news and entertainment, as well as satire, games, and radio broadcasts for children. Radio SRF 1 broadcasts regional content several times a day in the following areas of German-speaking Switzerland: * Aargau / Solothurn * Basel * Bern - Fribourg - Valais * Central Switzerland * Eastern Switzerland * Zürich / Schaffhausen Schaffhausen (; ; ; ; ), historically known in English as Shaffhouse, is a list of towns ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiotelevisione Svizzera
Radiotelevisione svizzera, officially Radiotelevisione svizzera di lingua italiana (; "Swiss Radiotelevision of the Italian Language"), shortened to RSI (formerly RTSI until 2009), is a subsidiary of the Swiss Broadcasting Corporation (SRG SSR), operating in Italian-speaking Switzerland. Besides Italian, it also handles the production and broadcasting of programs in Lombard. Its administrative headquarters are located in Via Canevascini in Lugano. History ''Radio svizzera di lingua italiana'' was established in 1925 as ''Radio Monte Ceneri'', originally named after the mountain where the transmitter was placed. After several years of experimental broadcast, in 1933 the ''Società svizzera di Radiodiffusione'' (Swiss Radio Broadcasting Corporation) began regular transmissions in Ticino and Grigioni. The intentions of its founders were to promote cohesion in the confederation while promoting the value of the Swiss Italian culture. In the 1930s and 1940s, when most of Swi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Swissinfo
SWI swissinfo.ch is a Swiss Multilingualism, multilingual international news and information company based in Bern. It is a part of the Swiss Broadcasting Corporation (SRG SSR). Its content is Swiss-centred, with top priority given to in-depth information on politics, the economy, the arts, science, education, and direct democracy. Switzerland's international political, economic and cultural relations are other key points of focus. The website is available in ten languages. History SWI swissinfo.ch emerged from the Swiss Radio International (SRI), a business unit of SRG SSR for foreign countries. It was founded in 1935 and had the task of informing the Swiss abroad about what is happening in Switzerland and promoting Switzerland's presence abroad. Originally, radio programs were broadcast via short wave and later via satellites. In the mid-1990s, economic circumstances forced swissinfo.ch to take a new strategic direction. The internet was advancing fast, heralding a new era ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
