The National Broadcasting Company is an American English-language commercial terrestrial television network, a flagship property of NBCUniversal, a subsidiary of Comcast. The network is headquartered at 30 Rockefeller Plaza in New York City, with additional major offices near Los Angeles and Philadelphia; the network is one of the Big Three television networks. NBC is sometimes referred to as the "Peacock Network", in reference to its stylized peacock logo, introduced in 1956 to promote the company's innovations in early color broadcasting, it became the network's official emblem in 1979. Founded in 1926 by the Radio Corporation of America, NBC is the oldest major broadcast network in the United States. At that time the parent company of RCA was General Electric. In 1930, GE was forced to sell the companies as a result of antitrust charges. In 1986, control of NBC passed back to General Electric through its $6.4 billion purchase of RCA. Following the acquisition by GE, Bob Wright served as chief executive officer of NBC, remaining in that position until his retirement in 2007, when he was succeeded by Jeff Zucker.
In 2003, French media company Vivendi merged its entertainment assets with GE, forming NBC Universal. Comcast purchased a controlling interest in the company in 2011, acquired General Electric's remaining stake in 2013. Following the Comcast merger, Zucker left NBCUniversal and was replaced as CEO by Comcast executive Steve Burke. NBC has thirteen owned-and-operated stations and nearly 200 affiliates throughout the United States and its territories, some of which are available in Canada and/or Mexico via pay-television providers or in border areas over-the-air. During a period of early broadcast business consolidation, radio manufacturer Radio Corporation of America acquired New York City radio station WEAF from American Telephone & Telegraph. Westinghouse, a shareholder in RCA, had a competing outlet in Newark, New Jersey pioneer station WJZ, which served as the flagship for a loosely structured network; this station was transferred from Westinghouse to RCA in 1923, moved to New York City. WEAF acted as a laboratory for AT&T's manufacturing and supply outlet Western Electric, whose products included transmitters and antennas.
The Bell System, AT&T's telephone utility, was developing technologies to transmit voice- and music-grade audio over short and long distances, using both wireless and wired methods. The 1922 creation of WEAF offered a research-and-development center for those activities. WEAF maintained a regular schedule of radio programs, including some of the first commercially sponsored programs, was an immediate success. In an early example of "chain" or "networking" broadcasting, the station linked with Outlet Company-owned WJAR in Providence, Rhode Island. C. WCAP. New parent RCA saw an advantage in sharing programming, after getting a license for radio station WRC in Washington, D. C. in 1923, attempted to transmit audio between cities via low-quality telegraph lines. AT&T refused outside companies access to its high-quality phone lines; the early effort fared poorly, since the uninsulated telegraph lines were susceptible to atmospheric and other electrical interference. In 1925, AT&T decided that WEAF and its embryonic network were incompatible with the company's primary goal of providing a telephone service.
AT&T offered to sell the station to RCA in a deal that included the right to lease AT&T's phone lines for network transmission. RCA spent $1 million to purchase WEAF and Washington sister station WCAP, shut down the latter station, merged its facilities with surviving station WRC; the division's ownership was split among RCA, its founding corporate parent General Electric and Westinghouse. NBC started broadcasting on November 15, 1926. WEAF and WJZ, the flagships of the two earlier networks, were operated side-by-side for about a year as part of the new NBC. On January 1, 1927, NBC formally divided their respective marketing strategies: the "Red Network" offered commercially sponsored entertainment and music programming. Various histories of NBC suggest the color designations for the two networks came from the color of the pushpins NBC engineers used to designate affiliate stations of WEAF and WJZ, or from the use of double-ended red and blue colored pencils. On April 5, 1927, NBC expanded to the West Coast with the launch of the NBC Orange Network known as the Pacific Coast Network.
This was followed by the debut of the NBC Gold Network known as the Pacific Gold Network, on October 18, 1931. The Orange Network carried Red Network programming, the Gold Network carried programming from the Blue Network; the Orange Network recreated Eastern Red Network programming for West Coast stations at KPO in San Francisco. In 1936, the Orange Network affiliate stations became part of the Red Network, at the same time the Gold Network became part of the Blue Network. In the 1930s, NBC developed a network for shortwave radio stations, called the NBC White Network. In 1927, NBC moved its operations to 711 Fifth Avenue in Manhattan, occupying the upper floors of a building de
Telemundo is an American Spanish language terrestrial television network owned by Comcast through NBCUniversal. It is the second largest provider of Spanish language content nationally behind American competitor Univision, with programming syndicated worldwide to more than 100 countries in over 35 languages; the channel broadcasts programs and original content aimed at Latin American audiences in the United States and worldwide, consisting of telenovelas, reality television, news programming and films — either imported or Spanish-dubbed. In addition, Telemundo operates NBC Universo, a separate channel directed towards young Hispanic audiences. Telemundo is headquartered in the Miami suburb of Beacon Lakes, has 1,900 employees worldwide; the majority of Telemundo's programs are filmed at an operated studio facility in Miami, where 85% of the network's telenovelas were filmed during 2011. The average hourly primetime drama costs $70K to produce. Launched as NetSpan in 1984, the network was renamed Telemundo in 1987, after the network owners purchased the previous owner of WKAQ-TV, a television station in San Juan, Puerto Rico, branded on air as Telemundo.
WKAQ-TV was signed on on March 28, 1954, was founded by Ángel Ramos – owner of Puerto Rico's main newspaper at the time, El Mundo, the U. S. territory's first radio station, WKAQ. Ramos wanted to maintain a consistent branding for his media properties based around the "mundo" theme, chose to brand his new television property as "Telemundo". On April 14, 1983, Ramos sold WKAQ-TV to John Co.. In 1984, the owners of WNJU in Linden, New Jersey and KSTS in San Jose, California formed NetSpan, the second Spanish-language television network in the continental United States; these stations joined KVEA in Los Angeles, run by its general manager and part-owner Joe Wallach, in 1985. The following year, KVEA's part-owner, Reliance Group Holdings, acquired the Telemundo brand when it purchased John Blair & Co. which owned WSCV in Fort Lauderdale–Miami-West Palm Beach in addition to WKAQ-TV. In late 1986, Reliance purchased WNJU. In 1987, Reliance Capital Group executives Saul Steinberg and Henry Silverman merged all these stations into the Telemundo Group.
The new corporation went public, in 1987, Reliance decided to rebrand NetSpan as Telemundo. That year, it purchased additional stations in San Francisco and San Antonio. Between 1988 and 1993, Telemundo acquired or affiliated with television stations in Texas, New Mexico and Washington, D. C.. In May 1992, Telemundo underwent another management change, appointing former Univision president Joaquin Blaya – who resigned from that network after discovering in an FCC filing for A. Jerrold Perenchio's purchase of the network from Hallmark Cards that Univision would increase its reliance on programming from Televisa and Venevision to levels that resulted in him concluding that there would be fewer opportunities for the addition of local programs on Univision's stations, was subsequently joined by four other Univision executives – to head the network; the following year in 1993, Telemundo underwent an extensive rebranding, introducing the signature framed "T" letter logo, a promotional campaign using the slogan "Arriba, Arriba".
The network began to produce its own original telenovelas, the first of which to premiere were Angélica, mi vida, Guadalupe, Señora Tentación and Tres Destinos. International distributors soon approached the network for the syndication rights to air these programs on television networks in other countries. Telemundo's effort faced an initial setback when Mexico's leading broadcaster, purchased production company Capitalvision, producing the telenovelas in conjunction with the network. Parent company Telemundo Group experienced major financial challenges during this time, filing for Chapter 11 bankruptcy protection in 1994, due to a debt load of more than $300 million that the company owed to its creditors. In an effort to boost its tepid ratings and quell complaints from advocacy organizations such as the National Hispanic Media Coalition that criticized both networks for not featuring content relatable to American Latinos, Telemundo outlined a new strategy to better compete against Univision by increasing production of domestically produced programs.
In 1995, under the direction of executive vice president of programming Harry Abraham Castillo, Telemundo opened its first network studio on the West Coast. Housed at Raleigh Studios in Hollywood, the network began daily production of three shows on the lot that year: La Hora Lunática, a daytime talk-variety show hosted by Los Angeles radio personality Humberto Luna, comedians Mario Ramírez Reyes "El Comodín" and Hugo Armando, producer Jackie Torres.
Time Warner Cable
Time Warner Cable was an American cable television company. Before it was purchased by Charter Communications on May 18, 2016, it was ranked the second largest cable company in the United States by revenue behind only Comcast, operating in 29 states, its corporate headquarters were located in the Time Warner Center in Midtown Manhattan, New York City, with other corporate offices in Stamford, Connecticut. From 1971 to 1981, Time Warner Cable, as Warner Cable, owned Dimension Pictures, it was controlled by Warner Communications by Time Warner. That company spun off the cable operations in March 2009 as part of a larger restructuring. From 2009 to 2016, Time Warner Cable was an independent company, continuing to use the Time Warner name under license from its former parent. In 2014, the company was the subject of a proposed purchase by Comcast Corporation, valued at $45.2 billion. S. government to try to block the merger, Comcast called off the deal in April 2015. On May 26, 2015, Charter Communications announced that it would acquire Time Warner Cable for $78.7 billion, along with Bright House Networks in a separate $10.1 billion deal, pending regulatory approval.
The purchase was completed on May 18, 2016. Time Warner Cable was formed in 1992 by the merger of Time Inc.'s cable television company, American Television and Communications Corp. and Warner Cable, a division of Warner Communications, as a result of a merger to form Time Warner. It includes the remnants of the defunct QUBE interactive TV service. In 1995, the company launched the Southern Tier On-Line Community, a cable modem service known as Road Runner High Speed Online; that year, talks began that would result in Warner's acquisition of Paragon Cable. Glenn Britt was the CEO from 2001 until December 2013. Time Warner retained Time Warner Cable as a subsidiary until March 2009, when it was spun out as an independent company. Prior to the spin-out, Time Warner had held an 84% stake in Time Warner Cable. Non-Time Warner shareholders received 0.083670 shares for each share owned. This move made Time Warner Cable the largest cable operator in the United States owned by a single class of shareholders.
Time Warner Cable launched DVR service in the Houston area in 2004. When first launched, it used Scientific-Atlanta set-top boxes with DVR. In June 2009, Time Warner Cable unveiled a concept known as "TV Everywhere"—a means of allowing multi-platform access to live and on-demand content from television channels, tied to a user's television subscription, it was first reported in October 2013 that Time Warner Cable was exploring a sale of the company to Charter Communications. However, on November 22, 2013, reports surfaced that Comcast expressed interest in acquiring Time Warner Cable. Both companies were said to be placing bids for the company. Charter reiterated its interest in purchasing Time Warner Cable and increased its bid on January 14, 2014. On February 12, 2014, it was reported that Comcast had reached a deal to acquire TWC in an overall deal valued at $45.2 billion, pending regulatory approval. The proposed merger was met with prominent opposition from various groups, showing concerns that the sheer size of the combined company would reduce competition and would give Comcast an unprecedented level of control over the United States' internet and television industries, increased leverage in the distribution of NBCUniversal content, hamper over-the-top services, lead to higher prices for its services.
In April 2015, it was reported that the U. S. Department of Justice was preparing to file an antitrust lawsuit against the companies in a bid to halt the merger because the merged company would have controlled 57 percent of the nation's broadband capacity. On April 24, 2015, Comcast announced that it had called off the merger. On May 25, 2015, Bloomberg News reported that Charter was "near" a deal to acquire TWC for $195 a share. Charter had been involved in the Comcast/TWC merger, as the companies planned to divest around 4 million subscribers to Charter in order to reduce the combined company's market share to an acceptable level; the next day, Charter announced its intent to acquire Time Warner Cable in a deal valued at $78.7 billion, confirmed that it would continue with its proposed, $10.1 billion acquisition of Bright House Networks. The deal was subject to regulatory approval, although due to the smaller size of the companies and their media holdings, the deal was expected to face less resistance than the Comcast/TWC merger.
The acquisition was completed on May 18, 2016. The Time Warner Cable brand was phased out in favor of Spectrum, the brand used by Charter since 2014 to market its s
KTLA, virtual channel 5, is a CW-affiliated television station licensed to Los Angeles, United States. The station is owned by the Tribune Broadcasting subsidiary of the Tribune Media Company. KTLA's studios are located at the Sunset Bronson Studios at 5800 Sunset Boulevard in Hollywood, its transmitter is located atop Mount Wilson. KTLA was the first commercially licensed television station in the western United States, having begun operations in January 1947. Although not as widespread in national carriage as its Chicago sister station WGN-TV, KTLA is available as a superstation throughout North America via DirecTV and Dish Network, as well as on cable providers in select cities within the southwestern United States and throughout Canada; the station was licensed by the Federal Communications Commission in 1939 as experimental station W6XYZ, broadcasting on VHF channel 4. The station was owned by Paramount Pictures subsidiary Television Productions, Inc. and was based at the Paramount Studios lot.
Klaus Landsberg an accomplished television pioneer at the age of 26, was the original station manager and engineer. On January 22, 1947, the station was licensed for commercial broadcasting as KTLA on channel 5, becoming the first commercial television station in Los Angeles, the first to broadcast west of the Mississippi River, the eighth commercial television station in the United States. Estimates of television sets in Los Angeles County at the time ranged from 350 to 600, since experimental station W6XAO was in operation broadcasting with a regular schedule. Bob Hope served as the emcee for KTLA's inaugural broadcast, titled as The Western Premiere of Commercial Television, broadcast live that evening from a garage on the Paramount Studios lot and featured appearances from many Hollywood luminaries. Hope delivered what was the most famous line of the telecast when, at the program's start, he identified the new station as "KTL" – mistakenly omitting the "A" at the end of the call sign. A 10-minute fragment from KTLA's first broadcast exists at the Paley Center for Media.
KTLA was affiliated with the DuMont Television Network, of which Paramount held a minority stake. Despite this, the FCC still considered Paramount as controlling manager of DuMont due to the strength of the company's voting stock and their influence in managing the network; as a result, the agency did not allow DuMont to buy additional VHF stations—a problem that would play a large role in the failure of DuMont, whose programming was splintered among other Los Angeles stations—including KTSL, KHJ-TV, KTTV and KCOP-TV —until the network's demise in 1956. Paramount launched a short-lived programming service, the Paramount Television Network, in 1948, with KTLA and WBKB-TV in Chicago serving as its flagship stations; the service never gelled into a true television network, but during KTLA's early years, the station produced over a dozen series that were syndicated in much of the U. S. including Armchair Detective, Bandstand Revue, Dixie Showboat, Frosty Frolics, Hollywood Reel, Hollywood Wrestling, Latin Cruise, Movietown, RSVP, Olympic Wrestling, Sandy Dreams, Time for Beany.
In 1958, KTLA moved its operations into the Paramount Sunset Studios on Sunset Boulevard in Hollywood. For many years, those who have worked on Stage 6 at KTLA were told that it was the site where Al Jolson's landmark film The Jazz Singer was shot in 1927, when the lot was known as the Warner Bros. Sunset Studios; the former Warner Bros./Paramount lot is now known as Sunset Bronson Studios, where KTLA's facility remains based to this day, where shows such as WKRP in Cincinnati, Judge Judy, Hannah Montana, The Gong Show, Solid Gold, Name That Tune, Family Feud, The Newlywed Game, MADtv and Let's Make a Deal have been produced over the years. KTLA is the only Los Angeles area broadcaster that remains based in Hollywood as many other television and radio stations have moved to other parts of the region. In November 1963, KTLA was purchased by singer Gene Autry for $12 million. During the 1970s, KTLA became one of the nation's first superstations. KTLA sought a different programming strategy from its competitors during the late 1960s and 1970s, emphasizing syndicated reruns of off-network hour long dramas with a heavy emphasis on western-themed programs such as The Gene Autry Show, The Big Valley, first-run talk shows and sports programming.
Children's programs, with the exception of weekend morning Popeye cartoons, were phased out. Popeye continued Sunday Mornings but with only the 1960s King Features episodes. In the 1970s more drama shows like Kung Fu, Wo
San Diego is a city in the U. S. state of California. It is in San Diego County, on the coast of the Pacific Ocean in Southern California 120 miles south of Los Angeles and adjacent to the border with Mexico. With an estimated population of 1,419,516 as of July 1, 2017, San Diego is the eighth-largest city in the United States and second-largest in California, it is part of the San Diego–Tijuana conurbation, the second-largest transborder agglomeration between the U. S. and a bordering country after Detroit–Windsor, with a population of 4,922,723 people. The city is known for its mild year-round climate, natural deep-water harbor, extensive beaches, long association with the United States Navy, recent emergence as a healthcare and biotechnology development center. San Diego has been called "the birthplace of California". Home to the Kumeyaay people, it was the first site visited by Europeans on what is now the West Coast of the United States. Upon landing in San Diego Bay in 1542, Juan Rodríguez Cabrillo claimed the area for Spain, forming the basis for the settlement of Alta California 200 years later.
The Presidio and Mission San Diego de Alcalá, founded in 1769, formed the first European settlement in what is now California. In 1821, San Diego became part of the newly independent Mexico, which reformed as the First Mexican Republic two years later. California became part of the United States in 1848 following the Mexican–American War and was admitted to the union as a state in 1850; the city is the seat of San Diego County and is the economic center of the region as well as the San Diego–Tijuana metropolitan area. San Diego's main economic engines are military and defense-related activities, international trade, manufacturing; the presence of the University of California, San Diego, with the affiliated UCSD Medical Center, has helped make the area a center of research in biotechnology. The original inhabitants of the region are now known as the San La Jolla people; the area of San Diego has been inhabited by the Kumeyaay people. The first European to visit the region was explorer Juan Rodríguez Cabrillo, sailing under the flag of Castile but born in Portugal.
Sailing his flagship San Salvador from Navidad, New Spain, Cabrillo claimed the bay for the Spanish Empire in 1542, named the site "San Miguel". In November 1602, Sebastián Vizcaíno was sent to map the California coast. Arriving on his flagship San Diego, Vizcaíno surveyed the harbor and what are now Mission Bay and Point Loma and named the area for the Catholic Saint Didacus, a Spaniard more known as San Diego de Alcalá. On November 12, 1602, the first Christian religious service of record in Alta California was conducted by Friar Antonio de la Ascensión, a member of Vizcaíno's expedition, to celebrate the feast day of San Diego. Permanent colonization of California and of San Diego began in 1769 with the arrival of four contingents of Spaniards from New Spain and the Baja California peninsula. Two seaborne parties reached San Diego Bay: the San Carlos, under Vicente Vila and including as notable members the engineer and cartographer Miguel Costansó and the soldier and future governor Pedro Fages, the San Antonio, under Juan Pérez.
An initial overland expedition to San Diego from the south was led by the soldier Fernando Rivera and included the Franciscan missionary and chronicler Juan Crespí, followed by a second party led by the designated governor Gaspar de Portolà and including the mission president Junípero Serra. In May 1769, Portolà established the Fort Presidio of San Diego on a hill near the San Diego River, it was the first settlement by Europeans in. In July of the same year, Mission San Diego de Alcalá was founded by Franciscan friars under Serra. By 1797, the mission boasted the largest native population in Alta California, with over 1,400 neophytes living in and around the mission proper. Mission San Diego was the southern anchor in Alta California of the historic mission trail El Camino Real. Both the Presidio and the Mission are National Historic Landmarks. In 1821, Mexico won its independence from Spain, San Diego became part of the Mexican territory of Alta California. In 1822, Mexico began its attempt to extend its authority over the coastal territory of Alta California.
The fort on Presidio Hill was abandoned, while the town of San Diego grew up on the level land below Presidio Hill. The Mission was secularized by the Mexican government in 1834, most of the Mission lands were granted to former soldiers; the 432 residents of the town petitioned the governor to form a pueblo, Juan María Osuna was elected the first alcalde, defeating Pío Pico in the vote. However, San Diego had been losing population throughout the 1830s and in 1838 the town lost its pueblo status because its size dropped to an estimated 100 to 150 residents. Beyond town Mexican land grants expanded the number of California ranchos that modestly added to the local economy. Americans gained increased awareness of California, its commercial possibilities, from the writings of two countrymen involved in the officially forbidden, to foreigners, but economically significant hide and tallow trade, where San Diego was a major port and the only one with an adequate harbor: William Shaler's "Journal of a Voyage Between China and the North-Western Coast of America, Made in 1804" and Richard Henry Dana's more substantial and convincing account, of his 1834–36 voyage, the classic Two Years Before the Mast.
In 1846, the United States went to war against Mexico and sent a naval and land expedition to conquer Alta California. At firs
Cable television is a system of delivering television programming to consumers via radio frequency signals transmitted through coaxial cables, or in more recent systems, light pulses through fiber-optic cables. This contrasts with broadcast television, in which the television signal is transmitted over the air by radio waves and received by a television antenna attached to the television. FM radio programming, high-speed Internet, telephone services, similar non-television services may be provided through these cables. Analog television was standard in the 20th century, but since the 2000s, cable systems have been upgraded to digital cable operation. A "cable channel" is a television network available via cable television; when available through satellite television, including direct broadcast satellite providers such as DirecTV, Dish Network and Sky, as well as via IPTV providers such as Verizon FIOS and AT&T U-verse is referred to as a "satellite channel". Alternative terms include "non-broadcast channel" or "programming service", the latter being used in legal contexts.
Examples of cable/satellite channels/cable networks available in many countries are HBO, Cinemax, MTV, Cartoon Network, AXN, E!, FX, Discovery Channel, Canal+, Fox Sports, Disney Channel, Nickelodeon, CNN International, ESPN. The abbreviation CATV is used for cable television, it stood for Community Access Television or Community Antenna Television, from cable television's origins in 1948. In areas where over-the-air TV reception was limited by distance from transmitters or mountainous terrain, large "community antennas" were constructed, cable was run from them to individual homes; the origins of cable broadcasting for radio are older as radio programming was distributed by cable in some European cities as far back as 1924. To receive cable television at a given location, cable distribution lines must be available on the local utility poles or underground utility lines. Coaxial cable brings the signal to the customer's building through a service drop, an overhead or underground cable. If the subscriber's building does not have a cable service drop, the cable company will install one.
The standard cable used in the U. S. is RG-6, which has a 75 ohm impedance, connects with a type F connector. The cable company's portion of the wiring ends at a distribution box on the building exterior, built-in cable wiring in the walls distributes the signal to jacks in different rooms to which televisions are connected. Multiple cables to different rooms are split off the incoming cable with a small device called a splitter. There are two standards for cable television. All cable companies in the United States have switched to or are in the course of switching to digital cable television since it was first introduced in the late 1990s. Most cable companies require a set-top box or a slot on one's TV set for conditional access module cards to view their cable channels on newer televisions with digital cable QAM tuners, because most digital cable channels are now encrypted, or "scrambled", to reduce cable service theft. A cable from the jack in the wall is attached to the input of the box, an output cable from the box is attached to the television the RF-IN or composite input on older TVs.
Since the set-top box only decodes the single channel, being watched, each television in the house requires a separate box. Some unencrypted channels traditional over-the-air broadcast networks, can be displayed without a receiver box; the cable company will provide set top boxes based on the level of service a customer purchases, from basic set top boxes with a standard definition picture connected through the standard coaxial connection on the TV, to high-definition wireless DVR receivers connected via HDMI or component. Older analog television sets are "cable ready" and can receive the old analog cable without a set-top box. To receive digital cable channels on an analog television set unencrypted ones, requires a different type of box, a digital television adapter supplied by the cable company. A new distribution method that takes advantage of the low cost high quality DVB distribution to residential areas, uses TV gateways to convert the DVB-C, DVB-C2 stream to IP for distribution of TV over IP network in the home.
In the most common system, multiple television channels are distributed to subscriber residences through a coaxial cable, which comes from a trunkline supported on utility poles originating at the cable company's local distribution facility, called the "headend". Many channels can be transmitted through one coaxial cable by a technique called frequency division multiplexing. At the headend, each television channel is translated to a different frequency. By giving each channel a different frequency "slot" on the cable, the separate television signals do not interfere with each other. At an outdoor cable box on the subscriber's residence the company's service drop cable is connected to cables distributing the signal to different rooms in the building. At each television, the subscriber's television or a set-top box provided by the cable company translates the desired channel back to its original frequency, it is displayed onscreen. Due to widespread cable theft in earlier analog systems, the signals are encrypted on m
Analog television or analogue television is the original television technology that uses analog signals to transmit video and audio. In an analog television broadcast, the brightness and sound are represented by rapid variations of either the amplitude, frequency or phase of the signal. Analog signals vary over a continuous range of possible values which means that electronic noise and interference becomes reproduced by the receiver, thus with analog, a moderately weak signal becomes subject to interference. In contrast, a moderately weak digital signal and a strong digital signal transmit equal picture quality. Analog television can be distributed over a cable network using cable converters. All broadcast. Motivated by the lower bandwidth requirements of compressed digital signals, since the 2000s a digital television transition is proceeding in most countries of the world, with different deadlines for cessation of analog broadcasts; the earliest systems of analog television were mechanical television systems, which used spinning disks with patterns of holes punched into the disc to scan an image.
A similar disk reconstructed the image at the receiver. Synchronization of the receiver disc rotation was handled through sync pulses broadcast with the image information; however these mechanical systems were slow, the images were dim and flickered and the image resolution low. Camera systems used similar spinning discs and required intensely bright illumination of the subject for the light detector to work. Analog television did not begin as an industry until the development of the cathode-ray tube, which uses a focused electron beam to trace lines across a phosphor coated surface; the electron beam could be swept across the screen much faster than any mechanical disc system, allowing for more spaced scan lines and much higher image resolution. Far less maintenance was required of an all-electronic system compared to a spinning disc system. All-electronic systems became popular with households after the Second World War. Broadcasters of analog television encode their signal using different systems.
The official systems of transmission are named: A, B, C, D, E, F, G, H, I, K, K1, L, M and N. These systems determine the number of scan lines, frame rate, channel width, video bandwidth, video-audio separation, so on; the colors in those systems are encoded with one of three color coding schemes: NTSC, PAL, or SECAM, use RF modulation to modulate this signal onto a high frequency or ultra high frequency carrier. Each frame of a television image is composed of lines drawn on the screen; the lines are of varying brightness. The next sequential frame is displayed; the analog television signal contains timing and synchronization information, so that the receiver can reconstruct a two-dimensional moving image from a one-dimensional time-varying signal. The first commercial television systems were black-and-white. A practical television system needs to take luminance, chrominance and audio signals, broadcast them over a radio transmission; the transmission system must include a means of television channel selection.
Analog broadcast television systems come in a variety of frame resolutions. Further differences exist in the modulation of the audio carrier; the monochrome combinations still existing in the 1950s are standardized by the International Telecommunication Union as capital letters A through N. When color television was introduced, the hue and saturation information was added to the monochrome signals in a way that black and white televisions ignore. In this way backwards compatibility was achieved; that concept is true for all analog television standards. There were three standards for the way the additional color information can be encoded and transmitted; the first was the American NTSC color television system. The European/Australian PAL and the French-former Soviet Union SECAM standard were developed and attempt to cure certain defects of the NTSC system. PAL's color encoding is similar to the NTSC systems. SECAM, uses a different modulation approach than PAL or NTSC. In principle, all three color encoding systems can be combined with any scan line/frame rate combination.
Therefore, in order to describe a given signal it's necessary to quote the color system and the broadcast standard as a capital letter. For example, the United States, Canada and South Korea use NTSC-M, Japan uses NTSC-J, the UK uses PAL-I, France uses SECAM-L, much of Western Europe and Australia use PAL-B/G, most of Eastern Europe uses SECAM-D/K or PAL-D/K and so on. However, not all of these possible combinations exist. NTSC is only used with system M though there were experiments with NTSC-A in the UK and NTSC-N in part of South America. PAL is used with a variety of 625-line standards but with the North American 525-line standard, accordingly n