A television station is a set of equipment managed by a business, organisation or other entity such as an amateur television (ATV) operator, that transmits video content and audio content via radio waves directly from a transmitter on the earth's surface to any number of tuned receivers simultaneously.
36-432: WPAN (channel 53) is a television station licensed to Fort Walton Beach, Florida , United States, and also serving Pensacola . Its main channel primarily airs programming from Blab TV , a locally based channel that produces local infomercials and paid programming. Owned by B&C Communications, WPAN maintains transmitter facilities near Molino, Florida . The Fort Walton Beach Broadcasting Company applied in 1982 for
72-481: A barter in some cases. Nipkow disk A Nipkow disk (sometimes Anglicized as Nipkov disk; patented in 1884), also known as scanning disk , is a mechanical, rotating, geometrically operating image scanning device, patented by Paul Gottlieb Nipkow in Berlin . This scanning disk was a fundamental component in mechanical television , and thus the first televisions , through the 1920s and 1930s. The device
108-471: A great deal of flickering. The acquisition part of the system was not much better, requiring very powerful lighting of the subject. Disk scanners share a major limitation with the Farnsworth image dissector . Light is conveyed into the sensing system as the small aperture scans over the entire field of view. The actual amount of light gathered is instantaneous, occurring through a very small aperture, and
144-415: A much shorter wavelength, and thus requires a shorter antenna, but also higher power. North American stations can go up to 5000 kW ERP for video and 500 kW audio, or 1000 kW digital. Low channels travel further than high ones at the same power, but UHF does not suffer from as much electromagnetic interference and background "noise" as VHF, making it much more desirable for TV. Despite this, in
180-664: A new television station on channel 53 to serve that city, a plan that had been gestating since 1980. Construction began in 1983, with the station to be based at a site near Tupelo Avenue and 4th Street in Fort Walton Beach. WPAN intended to sign on in December 1983, but tower completion delays pushed the launch into 1984. The new station, which went on air on February 14, represented a $ 4 million investment. Programs telecast included family-oriented syndicated shows, movies, and sports. However, Fort Walton Beach could not operate
216-402: A postage-stamp in the case of a 30 to 50 cm diameter disk. Further disadvantages include the non-linear geometry of the scanned images, and the impractical size of the disk, at least in the past. The Nipkow disks used in early TV receivers were roughly 30 cm to 50 cm in diameter, with 30 to 50 holes. The devices using them were also noisy and heavy with very low picture quality and
252-425: A variety of ways to generate revenue from television commercials . They may be an independent station or part of a broadcasting network , or some other structure. They can produce some or all of their programs or buy some broadcast syndication programming for or all of it from other stations or independent production companies. Many stations have some sort of television studio , which on major-network stations
288-405: A week of airtime on WPAN starting November 1; remaining hours were filled by ValueVision and Video Catalog, home shopping services. Several attempts were made by Franklin over the years to sell the station, and it was silent for much of 2013 and 2014 pending sale. Neal Ardman was listed as managing the station in early 2013, when it began to air Cozi TV . It returned in 2014 with programming from
324-496: Is non-commercial educational (NCE) and considered public broadcasting . To avoid concentration of media ownership of television stations, government regulations in most countries generally limit the ownership of television stations by television networks or other media operators, but these regulations vary considerably. Some countries have set up nationwide television networks, in which individual television stations act as mere repeaters of nationwide programs . In those countries,
360-402: Is a mechanically spinning disk of any suitable material (metal, plastic, cardboard, etc.), with a series of equally-distanced circular holes of equal diameter drilled in it. The holes may also be square for greater precision. These holes are positioned to form a single-turn spiral starting from an external radial point of the disk and proceeding to the center of the disk. When the disk rotates,
396-470: Is broadcast via terrestrial radio waves. A group of television stations with common ownership or affiliation are known as a TV network and an individual station within the network is referred to as O&O or affiliate , respectively. Because television station signals use the electromagnetic spectrum, which in the past has been a common, scarce resource, governments often claim authority to regulate them. Broadcast television systems standards vary around
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#1732793991886432-792: Is often used for newscasts or other local programming . There is usually a news department , where journalists gather information. There is also a section where electronic news-gathering (ENG) operations are based, receiving remote broadcasts via remote pickup unit or satellite TV . Outside broadcasting vans, production trucks , or SUVs with electronic field production (EFP) equipment are sent out with reporters , who may also bring back news stories on video tape rather than sending them back live . To keep pace with technology United States television stations have been replacing operators with broadcast automation systems to increase profits in recent years. Some stations (known as repeaters or translators ) only simulcast another, usually
468-423: Is picked up as a temporal pattern of light and dark by a sensor. If the sensor is made to control a light behind a second Nipkow disk rotating synchronously at the same speed and in the same direction, the image will be reproduced line-by-line. The size of the reproduced image is again determined by the size of the disc; a larger disc produces a larger image. When spinning the disk while observing an object "through"
504-411: Is that the receiving device is very similar to the acquisition device, except that the light-sensitive device is replaced by a variable light source, driven by the signal provided by the acquisition device. Some means of synchronizing the disks on the two devices must also be devised (several options are possible, ranging from manual to electronic control signals). These facts helped immensely in building
540-759: The Soul of the South Network . From May 2015 to May 2016, WPAN was off the air under special temporary authority to be silent, as Franklin could not pay the electricity bill and had been placed into receivership; on May 16, WPAN returned to the air under new owners B&C Communications as an affiliate of the Vibrant TV Network, and then in February 2019, after the Vibrant TV network ceased operations, it switched to carrying Antenna TV . WPAN went off
576-405: The broadcast range , or geographic area, that the station is limited to, allocates the broadcast frequency of the radio spectrum for that station's transmissions, sets limits on what types of television programs can be programmed for broadcast and requires a station to broadcast a minimum amount of certain programs types, such as public affairs messages . Another form of television station
612-534: The electricity bill and emergency backup generators . In North America , full-power stations on band I (channels 2 to 6) are generally limited to 100 kW analog video ( VSB ) and 10 kW analog audio ( FM ), or 45 kW digital ( 8VSB ) ERP. Stations on band III (channels 7 to 13) can go up by 5 dB to 316 kW video, 31.6 kW audio, or 160 kW digital. Low-VHF stations are often subject to long-distance reception just as with FM. There are no stations on Channel 1 . UHF , by comparison, has
648-456: The Nipkow disk as an image scanning device: the scanlines are not straight lines, but rather curves . So the ideal Nipkow disk should have either a very large diameter, which means smaller curvature , or a very narrow angular opening of its viewport. Another way to produce acceptable images would be to drill smaller holes (millimeter or even micrometer scale) closer to the outer sectors of
684-647: The U.S., the Federal Communications Commission (FCC) is taking another large portion of this band (channels 52 to 69) away, in contrast to the rest of the world, which has been taking VHF instead. This means that some stations left on VHF are harder to receive after the analog shutdown . Since at least 1974, there are no stations on channel 37 in North America for radio astronomy purposes. Most television stations are commercial broadcasting enterprises which are structured in
720-578: The air in October 2019 due to a dispute with the tower owner, who expected the debt from the prior owners to be repaid in order to gain access to the transmitter. Since the station needed to move to channel 21 as part of the FCC repack, it opted to construct a new tower in Molino to offer market-wide coverage for the first time. WPAN returned to the airwaves in October 2020 after filing for another silent STA due to
756-410: The disk (and viewport), and so decomposing an image into lines is done almost by itself with little need for scanline timing, and very high scanline resolution . A simple acquisition device can be built by using an electrical motor driving a Nipkow disk, a small box containing a single light-sensitive (electric) element and a conventional image focusing device (lens, dark box , etc.). Another advantage
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#1732793991886792-400: The disk but a small rectangular area with black cardboard (which stays fixed), spinning the disk and observing an object through the small area. One of the advantages of using a Nipkow disk is that the image sensor (that is, the device converting light to electric signals) can be as simple as a single photocell or photodiode , since at each instant only a very small area is visible through
828-407: The disk, but technological evolution favoured electronic means of image acquisition. Another significant disadvantage lay with reproducing images at the receiving end of the transmission which was also accomplished with a Nipkow disk. The images were typically very small, as small as the surface used for scanning, which, with the practical implementations of mechanical television , were the size of
864-452: The disk, preferably through a relatively small circular sector of the disk (the viewport ), for example, an angular quarter or eighth of the disk, the object seems "scanned" line by line, first by length or height or even diagonally, depending on the exact sector chosen for observation. By spinning the disk rapidly enough, the object seems complete and capturing of motion becomes possible. This can be intuitively understood by covering all of
900-560: The first mechanical television accomplished by the Scottish inventor John Logie Baird , as well as the first "TV-Enthusiasts" communities and even experimental image radio broadcasts in the 1920s. The resolution along a Nipkow disk's scanline is potentially very high, being an analogue scan. However the maximum number of scanlines is much more limited, being equal to the number of holes on the disk, which in practice ranged from 30 to 100, with rare 200-hole disks tested. Another drawback of
936-420: The highest point available in the transmission area, such as on a summit , the top of a high skyscraper , or on a tall radio tower . To get a signal from the master control room to the transmitter, a studio/transmitter link (STL) is used. The link can be either by radio or T1 / E1 . A transmitter/studio link (TSL) may also send telemetry back to the station, but this may be embedded in subcarriers of
972-400: The holes trace circular ring patterns, with inner and outer diameter depending on each hole's position on the disk and thickness equal to each hole's diameter. The patterns may or may not partially overlap, depending on the exact construction of the disk. A lens projects an image of the scene in front of it directly onto the disk. Each hole in the spiral takes a "slice" through the image which
1008-400: The local television station has no station identification and, from a consumer's point of view, there is no practical distinction between a network and a station, with only small regional changes in programming, such as local television news . To broadcast its programs, a television station requires operators to operate equipment, a transmitter or radio antenna , which is often located at
1044-419: The main broadcast. Stations which retransmit or simulcast another may simply pick-up that station over-the-air , or via STL or satellite. The license usually specifies which other station it is allowed to carry. VHF stations often have very tall antennas due to their long wavelength , but require much less effective radiated power (ERP), and therefore use much less transmitter power output , also saving on
1080-446: The net yield is only a microscopic percentage of the incident energy. Iconoscopes (and their successors) accumulate energy on the target continuously, thereby integrating energy over time. The scanning system simply "picks off" the accumulated charge as it sweeps past each site on the target. Simple calculations show that, for equally sensitive photosensitive receptors, the iconoscope is hundreds to thousands of times more sensitive than
1116-476: The programmes seen on its owner's flagship station, and have no television studio or production facilities of their own. This is common in developing countries . Low-power stations typically also fall into this category worldwide. Most stations which are not simulcast produce their own station identifications . TV stations may also advertise on or provide weather (or news) services to local radio stations , particularly co-owned sister stations . This may be
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1152-502: The station from a financial standpoint, and it closed at midnight on November 16, 1986; one minority partner noted they simply could not sell enough advertising. Channel 53 returned to the air on July 1, 1988, under the aegis of Franklin Broadcasting. The station's new programming included more religious fare. It operated only sporadically, and at one point, it was affiliated with the short-lived Star Television Network . By 1991, it
1188-633: The tower situation. BLAB also returned to channel 53. The station's signal is multiplexed : The station formerly operated a repeater, W50CF, in Mobile, Alabama , which broadcast on analog channel 50 (and prior to that was W69AU channel 69). The translator was sold to Word of Life Community Church in Chickasaw, Alabama , before going off the air for good to make way for the digital signal of WFGX . Television station The Fernsehsender Paul Nipkow ( TV Station Paul Nipkow ) in Berlin , Germany ,
1224-462: The world. Television stations broadcasting over an analog system were typically limited to one television channel , but digital television enables broadcasting via subchannels as well. Television stations usually require a broadcast license from a government agency which sets the requirements and limitations on the station. In the United States, for example, a television license defines
1260-633: Was partially simulcasting WJTC in Pensacola in an agreement primarily conceived to allow some of that station's programs to be seen on cable systems otherwise unable to carry it. However, it would be dark for a full two years from 1991 to 1993. In 1993, the revival of must-carry legislation pushing channel 53 into more cable homes led to Franklin reviving WPAN, as did a contract with BLAB-TV (an acronym for "Basic Local Area Broadcasting"). BLAB, which produced local infomercials and sponsored segments for local businesses that aired on cable, purchased 37 hours
1296-678: Was the first regular television service in the world. It was on the air from 22 March 1935, until it was shut down in 1944. The station was named after Paul Gottlieb Nipkow , the inventor of the Nipkow disk . Most often the term "television station" refers to a station which broadcasts structured content to an audience or it refers to the organization that operates the station. A terrestrial television transmission can occur via analog television signals or, more recently, via digital television signals. Television stations are differentiated from cable television or other video providers as their content
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