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CCIR System I
CCIR System I is an analogue broadcast television system. It was first used in the Republic of Ireland starting in 1962 as the 625-line broadcasting standard to be used on VHF Band I and Band III, sharing Band III with 405-line System A signals radiated in the north and east of the country. The UK started its own 625-line television service in 1964 also using System I, but on UHF only – the UK has never used VHF for 625-line television except for some cable relay distribution systems. Since then, System I has been adopted for use by Hong Kong, Macau, the Falkland Islands and South Africa. The Republic of Ireland has (slowly) extended its use of System I onto the UHF bands. As of late 2012, analogue television is no longer transmitted in either the UK or the Republic of Ireland. South Africa is still broadcasting in System I, but plans to end the service in 2022. Specifications Some of the important specs are listed below. A frame is the total picture. The frame rate is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Comité Consultatif International Pour La Radio
The ITU Radiocommunication Sector (ITU-R) is one of the three sectors (divisions or units) of the International Telecommunication Union (ITU) and is responsible for radio communications. Its role is to manage the international radio-frequency spectrum and satellite orbit resources and to develop standards for radiocommunication systems with the objective of ensuring the effective use of the spectrum. ITU is required, according to its constitution, to allocate spectrum and register frequency allocation, orbital positions and other parameters of satellites, “in order to avoid harmful interference between radio stations of different countries”. The international spectrum management system is therefore based on regulatory procedures for frequency coordination, notification and registration. ITU-R has a permanent secretariat, the Radiocommunication Bureau, based at the ITU HQ in Geneva, Switzerland. The electeDirector of the Bureauis Mr. Mario Maniewicz; he was first elected by t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NICAM
Near Instantaneous Companded Audio Multiplex (NICAM) is an early form of lossy compression for digital audio. It was originally developed in the early 1970s for point-to-point links within broadcasting networks.Croll, M.G., Osborne, D.W. and Spicer, C.R. (1974), ''Digital sound signals: the present BBC distribution system and a proposal for bit-rate reduction by digital companding''. IEE Conference publication No. 119, pp. 90–96 In the 1980s, broadcasters began to use NICAM compression for transmissions of stereo TV sound to the public. History Near-instantaneous companding The idea was first described in 1964. In this, the 'ranging' was to be applied to the analogue signal before the analogue-to-digital converter (ADC) and after the digital-to-analogue converter (DAC). The application of this to broadcasting, in which the companding was to be done entirely digitally after the ADC and before the DAC, was described in a 1972 BBC Research Report. Point-to-point links NI ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Video Formats
Video is an electronic medium for the recording, copying, playback, broadcasting, and display of moving visual media. Video was first developed for mechanical television systems, which were quickly replaced by cathode-ray tube (CRT) systems which, in turn, were replaced by flat panel displays of several types. Video systems vary in display resolution, aspect ratio, refresh rate, color capabilities and other qualities. Analog and digital variants exist and can be carried on a variety of media, including radio broadcast, magnetic tape, optical discs, computer files, and network streaming. History Analog video Video technology was first developed for mechanical television systems, which were quickly replaced by cathode-ray tube (CRT) television systems, but several new technologies for video display devices have since been invented. Video was originally exclusively a live technology. Charles Ginsburg led an Ampex research team developing one of the first practica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Television Technology
Large-screen television technology (colloquially big-screen TV) developed rapidly in the late 1990s and 2000s. Prior to the development of thin-screen technologies, rear-projection television was standard for larger displays, and jumbotron, a non-projection video display technology, was used at stadiums and concerts. Various thin-screen technologies are being developed, but only liquid crystal display (LCD), plasma display (PDP) and Digital Light Processing (DLP) have been publicly released. Recent technologies like organic light-emitting diode (OLED) as well as not-yet-released technologies like surface-conduction electron-emitter display (SED) or field emission display (FED) are in development to replace earlier flat-screen technologies in picture quality. Large-screen technologies have almost completely displaced cathode-ray tubes (CRT) in television sales due to the necessary bulkiness of cathode-ray tubes. The diagonal screen size of a CRT television is limited to abou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ITU-R Recommendations
The ITU Radiocommunication Sector (ITU-R) is one of the three sectors (divisions or units) of the International Telecommunication Union (ITU) and is responsible for radio communications. Its role is to manage the international radio-frequency spectrum and satellite orbit resources and to develop standards for radiocommunication systems with the objective of ensuring the effective use of the spectrum. ITU is required, according to its constitution, to allocate spectrum and register frequency allocation, orbital positions and other parameters of satellites, “in order to avoid harmful interference between radio stations of different countries”. The international spectrum management system is therefore based on regulatory procedures for frequency coordination, notification and registration. ITU-R has a permanent secretariat, the Radiocommunication Bureau, based at the ITU HQ in Geneva, Switzerland. The electeDirector of the Bureauis Mr. Mario Maniewicz; he was first elected by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transposer
In broadcasting, a transposer or translator is a device in or beyond the service area of a radio or television station transmitter that rebroadcasts signals to receivers which can’t properly receive the signals of the transmitter because of a physical obstruction (like a hill). A translator receives the signals of the transmitter and rebroadcasts the signals to the area of poor reception. Sometimes the translator is also called a ''relay transmitter'', ''rebroadcast transmitter'' or ''transposer.'' Since translators are used to cover a small shadowed area, their output powers are usually lower than that of the radio or television station transmitters feeding them. Physical obstruction Reception of RF signals is sensitive to the size of obstruction in the path between the transmitter and the receiver. Generally speaking, if the size exceeds the wavelength the reception is interrupted. Since the wavelength is inversely proportional to frequency, it follows than that the higher ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Television Transmitter
A television transmitter is a transmitter that is used for terrestrial (over-the-air) television broadcasting. It is an electronic device that radiates radio waves that carry a video signal representing moving images, along with a synchronized audio channel, which is received by television receivers ('televisions' or 'TVs') belonging to a public audience, which display the image on a screen. A television transmitter, together with the broadcast studio which originates the content, is called a television station. Television transmitters must be licensed by governments, and are restricted to a certain frequency channel and power level. They transmit on frequency channels in the VHF and UHF bands. Since radio waves of these frequencies travel by line of sight, they are limited by the horizon to reception distances of 40–60 miles depending on the height of transmitter station. Television transmitters use one of two different technologies: ''analog'', in which the picture and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Five (TV Channel)
Channel 5 is a British free-to-air public broadcast television channel launched in 1997. It is the fifth national terrestrial channel in the United Kingdom and is owned by Channel 5 Broadcasting Limited, a wholly-owned subsidiary of American media conglomerate Paramount Global, which is grouped under Paramount Networks UK & Australia division. During ownership by the RTL Group, it was branded as Five between 16 September 2002 and 13 February 2011. Richard Desmond purchased the channel from RTL on 23 July 2010, announcing plans to invest more money in programming and return to the name Channel 5 with immediate effect, and it was relaunched on 14 February 2011. On 1 May 2014 the channel was acquired by Viacom (now Paramount Global) for £450 million (US$759 million). Channel 5 is a general entertainment channel that shows both internally commissioned programmes such as '' Our Yorkshire Farm'', ''The Gadget Show'', ''The Hotel Inspector'', and ''Can't Pay? We'll Take It A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Band V
Band V (meaning ''Band 5'') is the name of a radio frequency range within the ultra high frequency part of the electromagnetic spectrum. It is not to be confused with the ''V band'' in the extremely high frequency part of the spectrum. Sources differ on the exact frequency range of ''UHF Band V''. For example, the ''Broadcast engineer's reference book'' and the BBC define the range as 614 to 854 MHz. The '' IPTV India Forum'' define the range as 582 to 806 MHz and the '' DVB Worldwide'' website refers to the range as 585 to 806 MHz. Band V is primarily used for analogue and digital (DVB-T & ATSC) television broadcasting, as well as radio microphones and services intended for mobile devices such as DVB-H. With the close-down of analog television services most countries have auctioned off frequencies from 694 MHz and up to 4G cellular network providers. Television Australia In Australia UHF channel allocations are 7 MHz wide. Band V includes channels 36 to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Band IV
Band IV is the name of a radio frequency range within the ultra high frequency part of the electromagnetic spectrum. Sources differ on the exact frequency range of the band. For example, the ''Swiss Federal Office of Communications'', the ''Broadcast engineer's reference book'' and Ericsson India Ltd all define the range of Band IV from 470 to 582 MHz. An EICTA paper defines the range as 474 to 602 MHz, whilst the BBC define the range as 470 to 614 MHz. Band IV is primarily used for analogue and digital (DVB-T, ATSC and ISDB) television broadcasting, as well as services intended for mobile devices such as DVB-H. Television Australia In Australia UHF channel allocations are 7 MHz wide. Band IV includes channels 28 to 35, with base frequencies of 529.5 MHz to 578.5 MHz. More details are available on the television frequencies page. New Zealand In New Zealand UHF channel allocations are 8 MHz wide. Band IV includes channels 25 to 35, with base fr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
VHF Usage
Very high frequency (VHF) is the ITU designation for the range of radio frequency electromagnetic waves ( radio waves) from 30 to 300 megahertz (MHz), with corresponding wavelengths of ten meters to one meter. Frequencies immediately below VHF are denoted high frequency (HF), and the next higher frequencies are known as ultra high frequency (UHF). VHF radio waves propagate mainly by line-of-sight, so they are blocked by hills and mountains, although due to refraction they can travel somewhat beyond the visual horizon out to about 160 km (100 miles). Common uses for radio waves in the VHF band are Digital Audio Broadcasting (DAB) and FM radio broadcasting, television broadcasting, two-way land mobile radio systems (emergency, business, private use and military), long range data communication up to several tens of kilometers with radio modems, amateur radio, and marine communications. Air traffic control communications and air navigation systems (e.g. VOR and ILS) work ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NTSC
The first American standard for analog television broadcast was developed by National Television System Committee (NTSC)National Television System Committee (1951–1953), Report and Reports of Panel No. 11, 11-A, 12–19, with Some supplementary references cited in the Reports, and the Petition for adoption of transmission standards for color television before the Federal Communications Commission, n.p., 1953], 17 v. illus., diagrs., tables. 28 cm. LC Control No.:5402138Library of Congress Online Catalog/ref> in 1941. In 1961, it was assigned the designation CCIR System M, System M. In 1953, a second NTSC standard was adopted, which allowed for color television broadcast compatible with the existing stock of black-and-white receivers. It is one of three major color formats for analog television, the others being PAL and SECAM. NTSC color is usually associated with the System M. The only other broadcast television system to use NTSC color was the System J. Since the introdu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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