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Subsidiary Communications Authorization
Subsidiary Communications Authorization (SCA) in the United States, and Subsidiary Communications Multiplex Operation (SCMO) in Canada, is a subcarrier on a radio station, allowing the station to broadcast additional services as part of its signal. Background ''Subsidiary Communications Authorization'' is the United States Federal Communications Commission's official designation for this type of service. SCA was deregulated in 1983; since then, both AM and FM licensed broadcast stations have been allowed to use subcarriers in the United States in general without requiring separate authority; authorization is only required for some uses which are still otherwise regulated, such as common carrier or Land Mobile Radio Service transmissions. The fidelity (bandwidth) of SCA channels on FM is generally quite limited compared to that of the main program material, resulting in audio quality similar to AM radio broadcasting. By extension, the already limited bandwidth of AM means that it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subcarrier
A subcarrier is a sideband of a radio frequency carrier wave, which is modulated to send additional information. Examples include the provision of colour in a black and white television system or the provision of stereo in a monophonic radio broadcast. There is no physical difference between a carrier and a subcarrier; the "sub" implies that it has been derived from a carrier, which has been amplitude modulated by a steady signal and has a constant frequency relation to it. FM stereo Stereo broadcasting is made possible by using a subcarrier on FM radio stations, which takes the left channel and "subtracts" the right channel from it — essentially by hooking up the right-channel wires backward (reversing polarity) and then joining left and reversed-right. The result is modulated with suppressed carrier AM, more correctly called sum and difference modulation or SDM, at 38 kHz in the FM signal, which is joined at 2% modulation with the mono left+right audio (which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telemetry
Telemetry is the in situ collection of measurements or other data at remote points and their automatic transmission to receiving equipment (telecommunication) for monitoring. The word is derived from the Greek roots ''tele'', 'far off', and ''metron'', 'measure'. Systems that need external instructions and data to operate require the counterpart of telemetry: telecommand. Although the term commonly refers to wireless data transfer mechanisms (e.g., using radio, ultrasonic, or infrared systems), it also encompasses data transferred over other media such as a telephone or computer network, optical link or other wired communications like power line carriers. Many modern telemetry systems take advantage of the low cost and ubiquity of GSM networks by using SMS to receive and transmit telemetry data. A ''telemeter'' is a physical device used in telemetry. It consists of a sensor, a transmission path, and a display, recording, or control device. Electronic devices are widely u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ATSC 3
ATSC 3.0 is a major version of the ATSC standards for terrestrial television broadcasting created by the Advanced Television Systems Committee (ATSC). The standards are designed to offer support for newer technologies, including High Efficiency Video Coding (HEVC) for video channels of up to 4K resolution (2160p) at 120 frames per second, wide color gamut, high dynamic range, Dolby AC-4 and MPEG-H 3D Audio, datacasting capabilities, and more robust mobile television support. The capabilities have also been foreseen as a way to enable finer public alerting and targeted advertising. The first major deployment of ATSC 3.0 occurred in South Korea in May 2017, in preparation for the 2018 Winter Olympics. In November 2017, the FCC passed rules allowing American broadcast stations to voluntarily adopt ATSC 3.0 ("Next Gen TV"), provided that full-power stations preserve the availability of their programming in their city of license via legacy ATSC signals; adoption is being steer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Channel 6 Radio Stations In The United States
This is a review of low-power television stations (LPTV) in the United States, transmitting on VHF channel 6, which also operate as radio stations capable of being picked up by many standard FM receivers. These stations are colloquially known as "Franken FMs", a reference to Frankenstein's monster, because TV stations functioning as radio stations had not been envisioned by the Federal Communications Commission (FCC)."MeTV FM goes from low-power TV station to top-10 Chicago radio station" by Robert Channick, ''Chicago Tribune'', May 3, 2018. The FCC commonly refers to these stations as "FM6" operations. All of these FM transmissions are authorized for operation on a center frequency of 87.75 MHz. First devised in 2002, until Jul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Satellite
A satellite or an artificial satellite is an object, typically a spacecraft, placed into orbit around a celestial body. They have a variety of uses, including communication relay, weather forecasting, navigation ( GPS), broadcasting, scientific research, and Earth observation. Additional military uses are reconnaissance, early warning, signals intelligence and, potentially, weapon delivery. Other satellites include the final rocket stages that place satellites in orbit and formerly useful satellites that later become defunct. Except for passive satellites, most satellites have an electricity generation system for equipment on board, such as solar panels or radioisotope thermoelectric generators (RTGs). Most satellites also have a method of communication to ground stations, called transponders. Many satellites use a standardized bus to save cost and work, the most popular of which are small CubeSats. Similar satellites can work together as groups, forming constellatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Muzak Holdings
Muzak is an American brand of background music played in retail stores and other public establishments owned by Mood Media. The name ''Muzak'', a blend of music and the popular camera brand name Kodak, has been in use since 1934 and has been owned by various companies. The word ''Muzak'' has been a registered trademark of Muzak LLC since December 21, 1954. In 1981, Westinghouse bought the company and ran it until selling it to the Fields Company of Chicago, publishers of the ''Chicago Sun-Times'', on September 8, 1986. Muzak was based in various Seattle, Washington, locations from 1986 to 1999, after which it moved its headquarters to outside Charlotte in 2000. Formerly owned by Muzak Holdings, the brand was purchased in 2011 by Mood Media in a deal worth US$345 million. In the United States, due in part to the market dominance of Muzak Holdings, ''Muzak'' came to be used to refer to most forms of background music, regardless of source. The term is also commonly used in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
WCLM (Chicago)
WCLM was a radio station operating on 101.9 FM in Chicago between 1957 and 1966. The station lost its broadcast license over several violations, the most notable of which was the use of its subsidiary communications authority (SCA) subcarrier facility to transmit the results of horse races on an additional audio channel. History Carol Music, Inc., a company that provided wired background music to businesses and restaurants, applied for a construction permit for a new FM station in Chicago on July 2, 1956. The Federal Communications Commission granted the permit on August 30. The transmitter was located on a tower atop 333 North Michigan, which was installed in March 1957. WCLM signed on May 25, 1957, broadcasting originally at 18 kW. The station later obtained authorization to increase its effective radiated power to 60 kW. It would not be long, however, before WCLM's broadcasts, which, like the wired service, were primarily oriented at retail establishments, came ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Closed-circuit Radio
A closed-circuit radio is a radio that emits over a very small range, typically a college campus. This system can be achieved from two ways: *By tying into the PA System *By using existing power lines, telephones lines, pipes, etc. to transmit a 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 conne ... References Radio communications {{radio-comm-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Signal (subscription Service)
A signal is both the process and the result of Signal transmission, transmission of data over some transmission media, media accomplished by embedding some variation. Signals are important in multiple subject fields including signal processing, information theory and biology. In signal processing, a signal is a function that conveys information about a phenomenon. Any quantity that can vary over space or time can be used as a signal to share messages between observers. The ''IEEE Transactions on Signal Processing'' includes audio signal, audio, video, speech, image, sonar, and radar as examples of signals. A signal may also be defined as observable change in a quantity over space or time (a time series), even if it does not carry information. In nature, signals can be actions done by an organism to alert other organisms, ranging from the release of plant chemicals to warn nearby plants of a predator, to sounds or motions made by animals to alert other animals of food. Signa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
