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Sign On
A sign-on (or start-up in Commonwealth countries except Canada) is the beginning of operations for a radio or television station, generally at the start of each day. It is the opposite of a sign-off (or closedown in Commonwealth countries except Canada), which is the sequence of operations involved when a radio or television station shuts down its transmitters and goes off the air for a predetermined period; generally, this occurs during the overnight hours although a broadcaster's digital specialty or sub-channels may sign-on and sign-off at significantly different times than its main channels. Like other television programming, sign-on and sign-off sequences can be initiated by a broadcast automation system, and automatic transmission systems can turn the carrier signal and transmitter on/off by remote control. Sign-on and sign-off sequences have become less common due to the increasing prevalence of 24/7 broadcasting. However, some national broadcasters continue the pra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ÄT Art
ÄT art is a Czech national television channel operated by Czech Television specialising in cultural content. The channel began broadcasting on 31 August 2013, with TomĂĄĹĄ Motl being its first executive director. ÄT art broadcasts from 8 pm to 6 am, and shares its frequency with children's channel ÄT :D which uses the remaining hours. Programming Each day begins with the news programme ''UdĂĄlosti v kultuĹe'' (), except on Sunday where ''TĂ˝den v kultuĹe'' () airs instead. These are supplemented by inputs from live events and current affairs talk shows with cultural themes. Across the week, each day is given a theme for programming: * Monday â ''Z prvnĂ Ĺady'' (The first row), student work, work from SlovenskĂĄ televĂzia. * Tuesday â ''ArtZĂłna'' * Wednesday â ''Klobouk dolĹŻ'' * Tuesday â ''Ĺ˝ivoty slavnĂ˝ch'' * Friday â ''Pop-rockovĂŠ podium'' * Saturday â ''Je nĂĄm ctĂ'' â celebrities, topics or events, musical show ''TeÄka za sobotnĂ nocďż˝ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Broadcast Relay Station
A broadcast relay station, also known as a satellite station, relay transmitter, broadcast translator (U.S.), re-broadcaster (Canada), repeater ( two-way radio) or complementary station (Mexico), is a broadcast transmitter which repeats (or transponds) the signal of a radio or television station to an area not covered by the originating station. These expand the broadcast range of a television or radio station beyond the primary signal's original coverage or improves service in the original coverage area. The stations may be (but are not usually) used to create a single-frequency network. They may also be used by an AM or FM radio station to establish a presence on the other band. Relay stations are most commonly established and operated by the same organisations responsible for the originating stations they repeat. Depending on technical and regulatory restrictions, relays may also be set up by unrelated organisations. Types Translators In its simplest form, a broadcast tra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transmitter Power Output
In radio transmission, transmitter power output (TPO) is the actual amount of power (in watts) of radio frequency (RF) energy that a transmitter produces at its output. TPO is a concept related to effective radiated power (ERP), but refers to the power output of a transmitter, without accounting for antenna gain. The ERP for VHF/UHF transmitters is normally more than the TPO, for LF/MF transmitters it has nearly the same value, while for VLF transmitters it may be less. Signal formula The radio antenna's design focuses the signal, creating gain and increasing the ERP. There is also some loss (negative gain) from the feedline, which reduces some of the TPO to the antenna by both resistance and by radiating a small part of the signal. The basic equation In mathematics, an equation is a mathematical formula that expresses the equality of two expressions, by connecting them with the equals sign . The word ''equation'' and its cognates in other languages may have subt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
City Of License
In U.S., Canadian, and Mexican broadcasting, a city of license or community of license is the community that a radio station or television station is officially licensed to serve by that country's broadcast regulator. In North American broadcast law, the concept of ''community of license'' dates to the early days of AM radio broadcasting. The requirement that a broadcasting station operate a ''main studio'' within a prescribed distance of the community which the station is licensed to serve appears in U.S. law as early as 1939. Various specific obligations have been applied to broadcasters by governments to fulfill public policy objectives of broadcast localism, both in radio and later also in television, based on the legislative presumption that a broadcaster fills a similar role to that held by community newspaper publishers. United States In the United States, the Communications Act of 1934 requires that "the Commission shall make such distribution of licenses, frequenci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Call Sign
In broadcasting and radio communications, a call sign (also known as a call name or call lettersâand historically as a call signalâor abbreviated as a call) is a unique identifier for a transmitter station. A call sign can be formally assigned by a government agency, informally adopted by individuals or organizations, or even cryptographically encoded to disguise a station's identity. The use of call signs as unique identifiers dates to the landline railroad telegraph system. Because there was only one telegraph line linking all railroad stations, there needed to be a way to address each one when sending a telegram. In order to save time, two-letter identifiers were adopted for this purpose. This pattern continued in radiotelegraph operation; radio companies initially assigned two-letter identifiers to coastal stations and stations on board ships at sea. These were not globally unique, so a one-letter company identifier (for instance, 'M' and two letters as a Mar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interval Signal
An interval signal, or tuning signal, is a characteristic sound or musical phrase used in international broadcasting, numbers stations, and by some domestic broadcasters, played before commencement or during breaks in transmission, but most commonly between programs in different languages. It serves several purposes: * It helps a listener using a radio with an analog electronics, analog tuner (radio), tuner to find the correct frequency. * It informs other stations that the frequency is in use. * It serves as a station identifier even if the language used in the subsequent broadcast is not one the listener understands. The practice began in Europe in the 1920s and 1930s and was carried over into shortwave broadcasts. The use of interval signals has declined with the advent of digital tuning systems, but has not vanished. Interval signals were not required on commercial channels in the United States, where jingles were used as identification. List of interval signals by station ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shortwave Radio
Shortwave radio is radio transmission using radio frequencies in the shortwave bands (SW). There is no official definition of the band range, but it always includes all of the High frequency, high frequency band (HF), which extends from 3 to 30 MHz (approximately 100 to 10 metres in wavelength). It lies between the Medium frequency, medium frequency band (MF) and the bottom of the Very high frequency, VHF band. Radio waves in the shortwave band can be reflected or refracted from a layer of electrically charged atoms in the atmosphere called the ionosphere. Therefore, short waves directed at an angle into the sky can be reflected back to Earth at great distances, beyond the horizon. This is called skywave or "skip" radio propagation, propagation. Thus shortwave radio can be used for communication over very long distances, in contrast to radio waves of higher frequency, which travel in straight lines (line-of-sight propagation) and are generally limited by the visual horizon, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DTMF
Dual-tone multi-frequency (DTMF) signaling is a telecommunication signaling system using the voice-frequency band over telephone lines between telephone equipment and other communications devices and switching centers. DTMF was first developed in the Bell System in the United States, and became known under the trademark Touch-Tone for use in push-button telephones, starting in 1963. The DTMF frequencies are standardized in ITU-T Recommendation Q.23. The signaling system is also known as ''MF4'' in the United Kingdom, as ''MFV'' in Germany, and ''Digitone'' in Canada. Touch-tone dialing with a telephone keypad gradually replaced the use of rotary dials and has become the industry standard in telephony to control equipment and signal user intent. The signaling on trunks in the telephone network uses a different type of multi-frequency signaling. Multifrequency signaling Before the development of DTMF, telephone numbers were dialed with rotary dials for loop-disconnect (LD) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ITV Nightscreen
''ITV Nightscreen'' was a scheduled programme on the ITV television network that was broadcast from 1998 to 2021. It consisted of a sequence of animated pages of information about ITV's upcoming programmes, features and special events, with easy listening music in the background. The programme was used to fill the station's overnight downtime, where a closedown would have once been used at the end of programmes. The programme was generally shown seven days a week with the typical weekday show airing from 4:05am to 5:05am daily. However, on ITV's digital channels, the amount of Teleshopping affects how much ''Nightscreen'' is broadcast. Origins and history Teletext screens had been used by the BBC since 1980 and by Channel 4 since 1983 to fill airtime cheaply. However teletext was only ever occasionally used on the ITV network due to ITV having been on air all day every day since the early 1970s. From April 1986, certain regions, firstly Central Independent Television, followed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hertz
The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), often described as being equivalent to one event (or Cycle per second, cycle) per second. The hertz is an SI derived unit whose formal expression in terms of SI base units is 1/s or sâ1, meaning that one hertz is one per second or the Inverse second, reciprocal of one second. It is used only in the case of periodic events. It is named after Heinrich Hertz, Heinrich Rudolf Hertz (1857â1894), the first person to provide conclusive proof of the existence of electromagnetic waves. For high frequencies, the unit is commonly expressed in metric prefix, multiples: kilohertz (kHz), megahertz (MHz), gigahertz (GHz), terahertz (THz). Some of the unit's most common uses are in the description of periodic waveforms and musical tones, particularly those used in radio- and audio-related applications. It is also used to describe the clock speeds at which computers and other electronics are driven. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Test Card
A test card, also known as a test pattern or start-up/closedown test, is a television test signal, typically broadcast at times when the transmitter is active but no program is being broadcast (often at sign-on and sign-off). Used since the earliest TV broadcasts, test cards were originally physical cards at which a television camera was pointed, allowing for simple adjustments of picture quality. Such cards are still often used for calibration, alignment, and matching of cameras and camcorders. From the 1950s, test card images were built into monoscope tubes which freed up the use of TV cameras which would otherwise have to be rotated to continuously broadcast physical test cards during downtime hours. Electronically generated test patterns, used for calibrating or troubleshooting the downstream signal path, were introduced in the late-1960s, and became commonly used from the 1970s and 80s. These are generated by test signal generators, which do not depend on the correct config ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
