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Asian Television Frequencies
VHF Japan People's Republic of China Original P.R.C. channel assignments Assignments since c.1975 Republic of China (Taiwan) Indonesia Kingdom of Thailand, other border of island ''Similar to the television frequency in America and Japan; same sound carrier as System M / N that uses 4.5 MHz sound carrier'' North Yala ''Channels 2,3,7 to 13 uses 4.5 MHz sound carrier (System N), Channel 4 uses 5 MHz carrier (system Y), Channels 5 and 6 uses 6.5 MHz sound carrier (system D)'' Russia,Kazakhstan,Turkmenistan,Azerbaijan,North Korea, Vietnam and most Central Asia UHF Japan People's Republic of China NOTE: The original assignments of Channels 25 to 57 were 2 MHz higher in frequency until c.1984. Channels 58 to 62 were deleted at this time. Indonesia, Singapore, Malaysia and most Asia,Middle East NOTE: Channels 22 to 48 are used for DVB-T2 digital TV broadcasting in Indonesia, Singapore, Malaysia and Brunei. Hong Kong and Macau See also *Broadcast tele ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Japan
Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north toward the East China Sea, Philippine Sea, and Taiwan in the south. Japan is a part of the Ring of Fire, and spans an archipelago of 6852 islands covering ; the five main islands are Hokkaido, Honshu (the "mainland"), Shikoku, Kyushu, and Okinawa. Tokyo is the nation's capital and largest city, followed by Yokohama, Osaka, Nagoya, Sapporo, Fukuoka, Kobe, and Kyoto. Japan is the eleventh most populous country in the world, as well as one of the most densely populated and urbanized. About three-fourths of the country's terrain is mountainous, concentrating its population of 123.2 million on narrow coastal plains. Japan is divided into 47 administrative prefectures and eight traditional regions. The Greater Tokyo Ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SECAM
SECAM, also written SÉCAM (, ''Séquentiel de couleur à mémoire'', French for ''color sequential with memory''), is an analog color television system that was used in France, some parts of Europe and Africa, and Russia. It was one of three major analog color television standards, the others being PAL and NTSC. This page primarily discusses the SECAM colour encoding system. The articles on broadcast television systems and analog television further describe frame rates, image resolution, and audio modulation. SECAM video is composite video because the luminance (luma, monochrome image) and chrominance (chroma, color applied to the monochrome image) are transmitted together as one signal. All the countries using SECAM are currently in the process of conversion, or have already converted to Digital Video Broadcasting (DVB), the new pan-European standard for digital television. SECAM remained a major standard into the 2000s. History Development of SECAM predates PAL, ... [...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] |
Australasian Television Frequencies
Television frequency allocation has evolved since the start of television in Australia in 1956, and later in New Zealand in 1960. There was no coordination between the national spectrum management authorities in either country to establish the frequency allocations. The management of the spectrum in both countries is largely the product of their economical and political situation. New Zealand didn't start to develop television service until 1965 due to World War 2 and its economic harm in the country's economy. The demand and planning for television in Australia intensified after WW2, with the Chifley government first favouring the existing British model (state monopoly) in 1948, and New Zealand used a similar model during the introduction of television in the 1960s. Private broadcasting did not come to the country until the 1980s, but there was no spectrum expansion to cope with the new arrangement. History Australia Australian television broadcasting commenced in 1956 in Mel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
North American Cable Television Frequencies
The Pan-American television frequencies are different for terrestrial and cable television systems. Terrestrial television channels are divided into two bands: the VHF band which comprises channels 2 through 13 and occupies frequencies between 54 and 216 MHz, and the UHF band, which comprises channels 14 through 36 and occupies frequencies between 470 and 700 MHz. These bands are different enough in frequency that they often require separate antennas to receive (although many antennas cover both VHF and UHF), and separate tuning controls on the television set. The VHF band is further divided into two frequency ranges: VHF low band (Band I) between 54 and 88 MHz, containing channels 2 through 6, and VHF high band (Band III) between 174 and 216 MHz, containing channels 7 through 13. The wide spacing between these frequency bands is responsible for the complicated design of rooftop TV antennas. The UHF band has higher noise and greater attenuation, so higher gain ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Channel 37
Channel 37 is an intentionally unused ultra-high frequency (UHF) television broadcasting channel by countries in most of ITU region 2 such as the United States, Canada, Mexico and Brazil. The frequency range allocated to this channel is important for radio astronomy, so all broadcasting is prohibited within a window of frequencies centred typically on . Similar reservations exist in portions of the Eurasian and Asian regions, although the channel numbering varies. History Channel 37 in System M and N countries occupied a band of UHF frequencies from . This band is particularly important to radio astronomy because it allows observation in a region of the spectrum in between the dedicated frequency allocations near 410 MHz and 1.4 GHz. The area reserved or unused differs from nation to nation and region to region (as for example the EU and British Isles have slightly different reserved frequency areas). One radio astronomy application in this band is for very-long-baselin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Knife-edge Effect
Diffraction is defined as the interference or bending of waves around the corners of an obstacle or through an aperture into the region of geometrical shadow of the obstacle/aperture. The diffracting object or aperture effectively becomes a secondary source of the propagating wave. Italian scientist Francesco Maria Grimaldi coined the word ''diffraction'' and was the first to record accurate observations of the phenomenon in 1660. In classical physics, the diffraction phenomenon is described by the Huygens–Fresnel principle that treats each point in a propagating wavefront as a collection of individual spherical wavelets. The characteristic bending pattern is most pronounced when a wave from a coherent source (such as a laser) encounters a slit/aperture that is comparable in size to its wavelength, as shown in the inserted image. This is due to the addition, or interference, of different points on the wavefront (or, equivalently, each wavelet) that travel by paths of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Early Television Stations
This is a list of pre-World War 2 television stations of the 1920s and 1930s. Most of these experimental stations were located in Europe (notably in the United Kingdom, France, Germany, Italy, Poland, the Netherlands, and Russia), Australia, Canada, and the United States. Some present-day broadcasters trace their origins to these early stations. All television licenses in the United States were officially "experimental" before July 1941, as the NTSC television standard had yet to be developed, and some American television broadcasters continued operating under experimental licenses as late as 1947, although by then they were using the same technical standards as their commercial brethren. List * Present North American broadcast television starts at 54 MHz (VHF) * Present day UK TV broadcasts begin at 470 MHz (UHF) See also * Timeline of the BBC * History of television * Timeline of the introduction of television in countries * Timeline of the introduction of col ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moving Image Formats
This article discusses moving image capture, transmission and presentation from today's technical and creative points of view; concentrating on aspects of frame rates. Essential parameters The essential parameters of any moving image sequence as a visual presentation are: presence or absence of colour, aspect ratio, resolution and image change rate. Image change rate There are several standard image-change rates (or frame rates) used today: 24 Hz, 25 Hz, 30 Hz, 50 Hz, and 60 Hz. Technical details related to the backward-compatible addition of color to the NTSC signal caused other variants to appear: 24000/1001 Hz, 30000/1001 Hz, and 60000/1001 Hz. The image change rate fundamentally affects how "fluid" the motion it captures will look on the screen. Moving image material, based on this, is sometimes divided into two groups: ''film-based'' material, where the image of the scene is captured by camera 24 times a second (24 Hz), and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NTSC-J
NTSC-J is the informal designation for the analogue television standard used in Japan. The system is based on the US NTSC ( NTSC-M) standard with minor differences. While NTSC-M is an official CCIR and FCCNational 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> standard, NTSC-J is a colloquial indicator. NTSC-J was replaced by ISDB, digital broadcasts in 44 of the country's 47 prefectures on 24 July 2011. Analogue broadcasting ended on 31 March 2012 in the three prefectures devastated by the 2011 Tōhoku earthquake and tsunami ( Iwate, Miyagi, Fukushima) and the subsequent Fukushima Daiichi nuclear disaster. The term NTSC-J is also used to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
People's Republic Of China
China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's List of countries and dependencies by population, most populous country, with a Population of China, population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and Borders of China, borders fourteen countries by land, the List of countries and territories by land borders, most of any country in the world, tied with Russia. Covering an area of approximately , it is the world's third List of countries and dependencies by area, largest country by total land area. The country consists of 22 provinces of China, provinces, five autonomous regions of China, autonomous regions, four direct-administered municipalities of China, municipalities, and two special administrative regions of China, Special Administrative Regions (Hong Kong and Macau). The national capital is Beijing, and the List of cities in China by population, most populous ci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
