161-507: Phase Alternating Line ( PAL ) is a colour encoding system for analog television . It was one of three major analogue colour television standards, the others being NTSC and SECAM . In most countries it was broadcast at 625 lines , 50 fields (25 frames) per second, and associated with CCIR analogue broadcast television systems B , D , G , H , I or K . The articles on analog broadcast television systems further describe frame rates , image resolution , and audio modulation. PAL video
322-414: A digital television (DTV) signal remains good until the signal level drops below a threshold where reception is no longer possible or becomes intermittent. Analog television may be wireless ( terrestrial television and satellite television ) or can be distributed over a cable network as cable television . All broadcast television systems used analog signals before the arrival of DTV. Motivated by
483-828: A fair trial . The English monarchs, through inheritance of substantial territories in France and claims to the French crown, were also heavily involved in conflicts in France, most notably the Hundred Years' War , while the Kings of Scots were in an alliance with the French during this period. Early modern Britain saw religious conflict resulting from the Reformation and the introduction of Protestant state churches in each country. The English Reformation ushered in political, constitutional, social and cultural change in
644-521: A subpolar oceanic climate . Higher elevations in Scotland experience a continental subarctic climate and the mountains experience a tundra climate . The prevailing wind is from the southwest and bears frequent spells of mild and wet weather from the Atlantic Ocean, although the eastern parts are mostly sheltered from this wind. Since the majority of the rain falls over the western regions,
805-604: A welfare state was established, and a comprehensive, publicly funded healthcare system, the National Health Service , was created. The rise of nationalism in the colonies coincided with Britain's much-diminished economic position, so that a policy of decolonisation was unavoidable. Independence was granted to India and Pakistan in 1947. Over the next three decades, most colonies of the British Empire gained their independence, and many became members of
966-408: A 6 MHz channel with a chrominance subcarrier frequency of 3.582056 MHz (917/4*H) similar to NTSC (910/4*H). On the studio production level, standard PAL cameras and equipment were used, with video signals then transcoded to PAL-N for broadcast. This allows 625 line, 50 frames per second video to be broadcast in a 6 MHz channel, at some cost in horizontal resolution . In Brazil, PAL
1127-584: A European signal. The BBC tested their pre-war (but still broadcast until 1985) 405-line monochrome system ( CCIR System A ) with all three colour standards including PAL, before the decision was made to abandon 405 and transmit colour on 625/ System I only. Many countries have turned off analogue transmissions, so the following does not apply anymore, except for using devices which output RF signals, such as video recorders . The majority of countries using or having used PAL have television standards with 625 lines and 50 fields per second. Differences concern
1288-887: A PAL-N TV broadcast can be sent to anyone in European countries that use PAL (and Australia/New Zealand, etc.) and it will display in colour. This will also play back successfully in Russia and other SECAM countries, as the USSR mandated PAL compatibility in 1985—this has proved to be very convenient for video collectors. People in Argentina, Paraguay and Uruguay usually own TV sets that also display NTSC-M, in addition to PAL-N. DirecTV also conveniently broadcasts in NTSC-M for North, Central, and South America. Most DVD players sold in Argentina, Paraguay and Uruguay also play PAL discs—however, this
1449-423: A comb-like effect known as Hanover bars on larger phase errors. Thus, most receivers now use a chrominance analogue delay line , which stores the received colour information on each line of display; an average of the colour information from the previous line and the current line is then used to drive the picture tube . The effect is that phase errors result in saturation changes, which are less objectionable than
1610-537: A delay line and suffering from the “ Hannover bars ” effect. An example of this solution is the Kuba Porta Color CK211P set. Another solution was to use a 1H analogue delay line to allow decoding of only the odd or even lines. For example, the chrominance on odd lines would be switched directly through to the decoder and also be stored in the delay line. Then, on even lines, the stored odd line would be decoded again. This method (known as 'gated NTSC')
1771-627: A given bandwidth. This is because sophisticated comb filters in receivers are more effective with NTSC's 4 color frame sequence compared to PAL's 8-field sequence. However, in the end, the larger channel width of most PAL systems in Europe still gives PAL systems the edge in transmitting more picture detail. In the SECAM television system, U and V are transmitted on alternate lines, using simple frequency modulation of two different color subcarriers. In some analog color CRT displays, starting in 1956,
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#17327657539461932-527: A given signal completely, it is necessary to quote the color system plus the broadcast standard as a capital letter. For example, the United States, Canada, Mexico and South Korea used (or use) NTSC-M , Japan used NTSC-J , the UK used PAL-I , France used SECAM-L , much of Western Europe and Australia used (or use) PAL-B / G , most of Eastern Europe uses SECAM-D / K or PAL-D/K and so on. Not all of
2093-463: A leading role in the movement to abolish slavery worldwide through the blockade of Africa and pressing other nations to end their trade with a series of treaties. In 1800 the parliaments of Great Britain and Ireland each passed an Act of Union, uniting the two kingdoms and creating the United Kingdom of Great Britain and Ireland on 1 January 1801. After the defeat of France at the end of
2254-454: A major issue considering Europe's geographical and weather-related particularities. To overcome NTSC's shortcomings, alternative standards were devised, resulting in the development of the PAL and SECAM standards. The goal was to provide a colour TV standard for the European picture frequency of 50 fields per second (50 hertz ), and finding a way to eliminate the problems with NTSC. PAL
2415-503: A means of television channel selection. Analog broadcast television systems come in a variety of frame rates and resolutions. Further differences exist in the frequency and modulation of the audio carrier. The monochrome combinations still existing in the 1950s were standardized by the International Telecommunication Union (ITU) as capital letters A through N. When color television was introduced,
2576-399: A number of different broadcast television systems are in use worldwide, the same principles of operation apply. A cathode-ray tube (CRT) television displays an image by scanning a beam of electrons across the screen in a pattern of horizontal lines known as a raster . At the end of each line, the beam returns to the start of the next line; at the end of the last line, the beam returns to
2737-800: A policy of splendid isolation in Europe, and attempted to contain Russian influence in Afghanistan and Persia , in what came to be known as the Great Game . During this time, Canada , Australia and New Zealand were granted self-governing dominion status. At the turn of the century, Britain's industrial dominance became challenged by the German Empire and the United States . The Edwardian era saw social reform and home rule for Ireland become important domestic issues, while
2898-421: A quasi-unique positive video modulation, system L) unless they are manufactured for the French market. They will correctly display plain (non-broadcast) CVBS or S-video SECAM signals. Many can also accept baseband NTSC-M, such as from a VCR or game console, and RF modulated NTSC with a PAL standard audio subcarrier (i.e., from a modulator), though not usually broadcast NTSC (as its 4.5 MHz audio subcarrier
3059-459: A result of a shortage of workers in the 1950s, the government encouraged immigration from Commonwealth countries . In the following decades, the UK became a more multi-ethnic society. Despite rising living standards in the late 1950s and 1960s, the UK's economic performance was less successful than many of its main competitors such as France, West Germany and Japan. The UK was the first democratic nation to lower its voting age to 18 in 1969. In
3220-399: A second demodulator, the Z demodulator, also extracts an additive combination of U plus V, but in a different ratio. The X and Z color difference signals are further matrixed into three color difference signals, (R-Y), (B-Y), and (G-Y). The combinations of usually two, but sometimes three demodulators were: In the end, further matrixing of the above color-difference signals c through f yielded
3381-811: A series of connected wars (including the English Civil War ) which led to the temporary overthrow of the monarchy, with the execution of King Charles I , and the establishment of the short-lived unitary republic of the Commonwealth of England , Scotland and Ireland. Although the monarchy was restored , the Interregnum along with the Glorious Revolution of 1688 and the subsequent Bill of Rights 1689 in England and Claim of Right Act 1689 in Scotland ensured that, unlike much of
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#17327657539463542-462: A signal would not be compatible with monochrome receivers, an important consideration when color broadcasting was first introduced. It would also occupy three times the bandwidth of existing television, requiring a decrease in the number of television channels available. Instead, the RGB signals are converted into YUV form, where the Y signal represents the luminance of the colors in the image. Because
3703-410: A television image is composed of scan lines drawn on the screen. The lines are of varying brightness; the whole set of lines is drawn quickly enough that the human eye perceives it as one image. The process repeats and the next sequential frame is displayed, allowing the depiction of motion. The analog television signal contains timing and synchronization information so that the receiver can reconstruct
3864-438: A two-dimensional moving image from a one-dimensional time-varying signal. The first commercial television systems were black-and-white ; the beginning of color television was in the 1950s. A practical television system needs to take luminance , chrominance (in a color system), synchronization (horizontal and vertical), and audio signals , and broadcast them over a radio transmission. The transmission system must include
4025-657: A typical bandwidth of 1.3 MHz. Composite PAL signal = E ′ Y + E ′ U sin ( ω t ) + E ′ V cos ( ω t ) + {\displaystyle =E'{\scriptstyle {\text{Y}}}+E'{\scriptstyle {\text{U}}}\sin(\omega t)+E'{\scriptstyle {\text{V}}}\cos(\omega t)+} timing where ω = 2 π F S C {\displaystyle \omega =2\pi F_{SC}} . Subcarrier frequency F S C {\displaystyle F_{SC}}
4186-480: A volt. At this point the IF signal consists of a video carrier signal at one frequency and the sound carrier at a fixed offset in frequency. A demodulator recovers the video signal. Also at the output of the same demodulator is a new frequency modulated sound carrier at the offset frequency. In some sets made before 1948, this was filtered out, and the sound IF of about 22 MHz was sent to an FM demodulator to recover
4347-459: Is Sound-in-Syncs . The luminance component of a composite video signal varies between 0 V and approximately 0.7 V above the black level. In the NTSC system, there is a blanking signal level used during the front porch and back porch, and a black signal level 75 mV above it; in PAL and SECAM these are identical. In a monochrome receiver, the luminance signal is amplified to drive
4508-411: Is composite video because luminance (luma, monochrome image) and chrominance (chroma, colour applied to the monochrome image) are transmitted together as one signal. A latter evolution of the standard, PALplus , added support for widescreen broadcasts with no loss of vertical image resolution , while retaining compatibility with existing sets. Almost all of the countries using PAL are currently in
4669-462: Is 100% for white level, 30% for black, and 0% for sync. The CVBS electrical amplitude is Vpp 1.0 V and impedance of 75 Ω . The vertical timings are: (Total vertical sync time 1.6 ms) As PAL is interlaced, every two fields are summed to make a complete picture frame. PAL colorimetry, as defined by the ITU on REC-BT.470, and based on CIE 1931 x,y coordinates: The assumed display gamma
4830-426: Is 4.43361875 MHz for PAL 4.43, compared to 3.579545 MHz for NTSC 3.58. The SECAM system, on the other hand, uses a frequency modulation scheme on its two line alternate colour subcarriers 4.25000 and 4.40625 MHz. The name "Phase Alternating Line" describes the way that the phase of part of the colour information on the video signal is reversed with each line, which automatically corrects phase errors in
4991-441: Is 4.43361875 MHz (±5 Hz) for PAL-B/D/G/H/I/N. The PAL colour system is usually used with a video format that has 625 lines per frame (576 visible lines, the rest being used for other information such as sync data and captioning) and a refresh rate of 50 interlaced fields per second (compatible with 25 full frames per second), such systems being B , G , H , I , and N (see broadcast television systems for
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5152-411: Is a constitutional monarchy and parliamentary democracy . The UK has three distinct jurisdictions: England and Wales , Scotland , and Northern Ireland . Since 1999, Scotland, Wales and Northern Ireland have their own governments and parliaments which control various devolved matters. A developed country , the UK has the world's sixth-largest economy by nominal gross domestic product (GDP). It
5313-600: Is a nuclear state , and is ranked fifth globally in military expenditure . The UK has been a permanent member of the UN Security Council since its first session in 1946. It is a member of the Commonwealth of Nations , Council of Europe , G7 , OECD , NATO , Five Eyes , AUKUS and CPTPP . British influence can be observed in the legal and political systems of many of its former colonies , and British culture remains globally influential, particularly in language , literature , music and sport . English
5474-411: Is a brief (about 1.5 microsecond ) period inserted between the end of each transmitted line of picture and the leading edge of the next line's sync pulse . Its purpose was to allow voltage levels to stabilise in older televisions, preventing interference between picture lines. The front porch is the first component of the horizontal blanking interval which also contains the horizontal sync pulse and
5635-420: Is also referred to as a "province". With regard to Northern Ireland, the descriptive name used "can be controversial, with the choice often revealing one's political preferences". The term "Great Britain" conventionally refers to the island of Great Britain, or politically to England, Scotland and Wales in combination. It is sometimes used as a loose synonym for the United Kingdom as a whole. The word England
5796-949: Is defined as 2.8. The PAL-M system uses color primary and gamma values similar to NTSC. Color is encoded using the YUV color space. Luma ( E ′ Y {\displaystyle E'{\scriptstyle {\text{Y}}}} ) is derived from red, green, and blue ( E ′ R , E ′ G , E ′ B {\displaystyle E'{\scriptstyle {\text{R}}},E'{\scriptstyle {\text{G}}},E'{\scriptstyle {\text{B}}}} ) gamma pre-corrected ( E ′ {\displaystyle E'} ) primary signals: E ′ U {\displaystyle E'{\scriptstyle {\text{U}}}} and E ′ V {\displaystyle E'{\scriptstyle {\text{V}}}} are used to transmit chrominance . Each has
5957-506: Is easier to tune the picture without losing the sound. So the FM sound carrier is then demodulated, amplified, and used to drive a loudspeaker. Until the advent of the NICAM and MTS systems, television sound transmissions were monophonic. The video carrier is demodulated to give a composite video signal containing luminance, chrominance and synchronization signals. The result is identical to
6118-473: Is not supported). Many sets also support NTSC with a 4.43 MHz color subcarrier (see PAL 60 on the next section). VHS tapes recorded from a PAL-N or a PAL-B/G, D/K, H, or I broadcast are indistinguishable because the downconverted subcarrier on the tape is the same. A VHS recorded off TV (or released) in Europe will play in colour on any PAL-N VCR and PAL-N TV in Argentina, Paraguay and Uruguay. Likewise, any tape recorded in Argentina, Paraguay or Uruguay off
6279-507: Is occasionally used incorrectly to refer to the United Kingdom as a whole, a mistake principally made by people from outside the UK. The term "Britain" is used as a synonym for Great Britain , but also sometimes for the United Kingdom. Usage is mixed: the UK Government prefers to use the term "UK" rather than "Britain" or "British" on its website (except when referring to embassies), while acknowledging that both terms refer to
6440-470: Is often known as "PAL 60" (sometimes "PAL 60/525", "Quasi-PAL" or "Pseudo PAL"). PAL-M (a broadcast standard) however should not be confused with "PAL 60" (a video playback system—see below). PAL television receivers manufactured since the 1990s can typically decode all of the PAL variants except, in some cases PAL-M and PAL-N. Many such receivers can also receive Eastern European and Middle Eastern SECAM, though rarely French-broadcast SECAM (because France used
6601-481: Is only the one specific nominal term 'Great Britain' which invariably excludes Northern Ireland". The BBC historically preferred to use "Britain" as shorthand only for Great Britain, though the present style guide does not take a position except that "Great Britain" excludes Northern Ireland. The adjective "British" is commonly used to refer to matters relating to the United Kingdom and is used in law to refer to United Kingdom citizenship and nationality . People of
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6762-449: Is only used on UHF. Although System I is used on both bands, it has only been used on UHF in the United Kingdom. The PAL-L (Phase Alternating Line with CCIR System L broadcast system) standard uses the same video system as PAL-B/G/H (625 lines, 50 Hz field rate, 15.625 kHz line rate), but with a larger 6 MHz video bandwidth rather than 5.5 MHz and moving the audio subcarrier to 6.5 MHz. An 8 MHz channel spacing
6923-538: Is ranked 2nd out of 180 countries in the Environmental Performance Index . A law has been passed that UK greenhouse gas emissions will be net zero by 2050. England accounts for 53 per cent of the UK, covering 50,350 square miles (130,395 km ). Most of the country consists of lowland terrain, with upland and mountainous terrain northwest of the Tees–Exe line which roughly divides
7084-468: Is that the U and V signals are zero when the picture has no color content. Since the human eye is more sensitive to detail in luminance than in color, the U and V signals can be transmitted with reduced bandwidth with acceptable results. In the receiver, a single demodulator can extract an additive combination of U plus V. An example is the X demodulator used in the X/Z demodulation system. In that same system,
7245-579: Is the Isle of Wight . Scotland accounts for 32 per cent of the UK, covering 30,410 square miles (78,772 km ). This includes nearly 800 islands , notably the Hebrides , Orkney Islands and Shetland Islands. Scotland is the most mountainous constituent country of the UK, the Highlands to the north and west are the more rugged region containing the majority of Scotland's mountainous land, including
7406-625: Is the German word for "breakage"). The first broadcasts began in the United Kingdom in July 1967, followed by West Germany at the Berlin IFA on August 25. The BBC channel initially using the broadcast standard was BBC2 , which had been the first UK TV service to introduce "625-lines" during 1964. The Netherlands and Switzerland started PAL broadcasts by 1968, with Austria following
7567-405: Is the difference between the B signal and the Y signal, also known as B minus Y (B-Y), and the V signal is the difference between the R signal and the Y signal, also known as R minus Y (R-Y). The U signal then represents how purplish-blue or its complementary color, yellowish-green, the color is, and the V signal how purplish-red or its complementary, greenish-cyan, it is. The advantage of this scheme
7728-500: Is the original television technology that uses analog signals to transmit video and audio. In an analog television broadcast, the brightness, colors and sound are represented by amplitude , phase and frequency of an analog signal. Analog signals vary over a continuous range of possible values which means that electronic noise and interference may be introduced. Thus with analog, a moderately weak signal becomes snowy and subject to interference. In contrast, picture quality from
7889-566: Is the same as the original U signal at the corresponding time. In effect, these pulses are discrete-time analog samples of the U signal. The pulses are then low-pass filtered so that the original analog continuous-time U signal is recovered. For V, a 90-degree shifted subcarrier briefly gates the chroma signal every 280 nanoseconds, and the rest of the process is identical to that used for the U signal. Gating at any other time than those times mentioned above will yield an additive mixture of any two of U, V, -U, or -V. One of these off-axis (that is, of
8050-511: Is the world's most widely spoken language and the third-most spoken native language . The Acts of Union 1707 declared that the Kingdom of England and Kingdom of Scotland were "United into One Kingdom by the Name of Great Britain". The term "United Kingdom" has occasionally been used as a description for the former Kingdom of Great Britain , although its official name from 1707 to 1800
8211-542: Is transmitted. Therefore, the receiver must reconstitute the subcarrier. For this purpose, a short burst of the subcarrier, known as the colorburst, is transmitted during the back porch (re-trace blanking period) of each scan line. A subcarrier oscillator in the receiver locks onto this signal (see phase-locked loop ) to achieve a phase reference, resulting in the oscillator producing the reconstituted subcarrier. NTSC uses this process unmodified. Unfortunately, this often results in poor color reproduction due to phase errors in
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#17327657539468372-490: Is used for PAL-L, to maintain compatibility with System L channel spacings. The PAL-N standard was created in Argentina , through Resolution No. 100 ME/76, which determined the creation of a study commission for a national color standard. The commission recommended using PAL under CCIR System N that Paraguay and Uruguay also used. It employs the 625 line/50 field per second waveform of PAL-B/G, D/K, H, and I, but on
8533-490: Is used in conjunction with the 525 line, 60 field/s CCIR System M , using (very nearly) the NTSC colour subcarrier frequency. Exact colour subcarrier frequency of PAL-M is 3.575611 MHz, or 227.25 times System M's horizontal scan frequency. Almost all other countries using system M use NTSC. The PAL colour system (either baseband or with any RF system, with the normal 4.43 MHz subcarrier unlike PAL-M) can also be applied to an NTSC-like 525-line picture to form what
8694-475: Is used to build the image. This process doubles the apparent number of video frames per second and further reduces flicker and other defects in transmission. The television system for each country will specify a number of television channels within the UHF or VHF frequency ranges. A channel actually consists of two signals: the picture information is transmitted using amplitude modulation on one carrier frequency, and
8855-413: Is used to reduce the channel spacing, which would be nearly twice the video bandwidth if pure AM was used. Signal reception is invariably done via a superheterodyne receiver : the first stage is a tuner which selects a television channel and frequency-shifts it to a fixed intermediate frequency (IF). The signal amplifier performs amplification to the IF stages from the microvolt range to fractions of
9016-635: Is usually mentioned as "PAL" (eg: "PAL DVD"). Likewise, video game consoles outputting a 50 Hz signal might be labeled as "PAL", as opposed to 60 Hz on NTSC machines. These designations should not be confused with the analog colour system itself. In the 1950s, the Western European countries began plans to introduce colour television, and were faced with the problem that the NTSC standard demonstrated several weaknesses, including colour tone shifting under poor transmission conditions, which became
9177-509: Is usually output in the European variant (colour subcarrier frequency 4.433618 MHz), so people who own a TV set which only works in PAL-N (plus NTSC-M in most cases) will have to watch those PAL DVD imports in black and white (unless the TV supports RGB SCART ) as the colour subcarrier frequency in the TV set is the PAL-N variation, 3.582056 MHz. Analog television Analog television
9338-588: The 1884 Reform Act championed by William Gladstone granting suffrage to a majority of males for the first time. The British population increased at a dramatic rate, accompanied by rapid urbanisation , causing significant social and economic stresses. By the late 19th century, the Conservatives under Benjamin Disraeli and Lord Salisbury initiated a period of imperial expansion in Africa , maintained
9499-401: The 625-line /50 Hz television system in general, to differentiate from the 525-line /60 Hz system generally used with NTSC. For example, DVDs were labelled as PAL or NTSC (referring to the line count and frame rate) even though technically the discs carry neither PAL nor NTSC encoded signal. These devices would still have analog outputs (ex; composite video output), and would convert
9660-534: The Atlantic slave trade , mainly between 1662 and 1807 when British or British-colonial slave ships transported nearly 3.3 million slaves from Africa. The slaves were taken to work on plantations , principally in the Caribbean but also North America . However, with pressure from the abolitionism movement , Parliament banned the trade in 1807, banned slavery in the British Empire in 1833, and Britain took
9821-650: The Battle of Culloden in 1746, after which the Scottish Highlanders were forcibly assimilated into Scotland by revoking the feudal independence of clan chiefs . The British colonies in North America that broke away in the American War of Independence became the United States . British imperial ambition turned towards Asia, particularly to India . British merchants played a leading part in
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#17327657539469982-715: The Cairngorms , Loch Lomond and The Trossachs and Ben Nevis which at 1,345 metres (4,413 ft) is the highest point in the British Isles. Wales accounts for less than 9 per cent of the UK, covering 8,020 square miles (20,779 km ). Wales is mostly mountainous, though South Wales is less mountainous than North and mid Wales . The highest mountains in Wales are in Snowdonia and include Snowdon ( Welsh : Yr Wyddfa ) which, at 1,085 metres (3,560 ft),
10143-523: The Commonwealth of Nations . The UK was the third country to develop a nuclear weapons arsenal (with its first atomic bomb test, Operation Hurricane , in 1952), but the post-war limits of Britain's international role were illustrated by the Suez Crisis of 1956. The international spread of the English language ensured the continuing international influence of its literature and culture . As
10304-704: The European Convention on Human Rights . The UK remained a great power with global diplomatic and military influence and a leading role in the United Nations and NATO . The UK broadly supported the United States' approach to the " war on terror " in the early 21st century. British troops fought in the War in Afghanistan , but controversy surrounded Britain's military deployment in Iraq , which saw
10465-583: The European Union (EU) in 1992, the UK was one of the 12 founding member states. From the late 1960s, Northern Ireland suffered communal and paramilitary violence (sometimes affecting other parts of the UK) conventionally known as the Troubles . It is usually considered to have ended with the 1998 Belfast "Good Friday" Agreement . Following a period of widespread economic slowdown and industrial strife in
10626-494: The Falkland Islands , leading to the 10-week Falklands War in which Argentine forces were defeated. The inhabitants of the islands are predominantly descendants of British settlers, and strongly favour British sovereignty, expressed in a 2013 referendum . From 1984, the UK economy was helped by the inflow of substantial North Sea oil revenues. Another British overseas territory, Gibraltar , ceded to Great Britain in
10787-545: The French Revolutionary Wars and Napoleonic Wars (1792–1815), the United Kingdom emerged as the principal naval and imperial power (with London the largest city in the world from about 1830). Unchallenged at sea , British dominance was later described as Pax Britannica ("British Peace"), a period of relative peace among the great powers (1815–1914) during which the British Empire became
10948-492: The ITU in 1961 as: 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, and so on. A color encoding scheme ( NTSC , PAL , or SECAM ) could be added to the base monochrome signal. Using RF modulation the signal is then modulated onto a very high frequency (VHF) or ultra high frequency (UHF) carrier wave . Each frame of
11109-532: The Kingdom of Ireland to create the United Kingdom of Great Britain and Ireland in 1801. Most of Ireland seceded from the UK in 1922 as the Irish Free State , and the Royal and Parliamentary Titles Act 1927 created the present United Kingdom. The UK became the first industrialised country and was the world's foremost power for the majority of the 19th and early 20th centuries, particularly during
11270-650: The Labour Party emerged from an alliance of trade unions and small socialist groups in 1900, and suffragettes campaigned for women's right to vote. Britain was one of the principal Allies that defeated the Central Powers in the First World War (1914–1918). Alongside their French, Russian and (after 1917) American counterparts, British armed forces were engaged across much of the British Empire and in several regions of Europe, particularly on
11431-480: The Philippines , and Taiwan . With the introduction of home video releases and later digital sources (e.g. DVD-Video ), the name "PAL" might be used to refer to digital formats, even though they use completely different colour encoding systems. For instance, 576i (576 interlaced lines) digital video with colour encoded as YCbCr , intended to be backward compatible and easily displayed on legacy PAL devices,
11592-544: The RCA brand and licences it to other companies; Radio Corporation of America , the originator of that brand, created the NTSC colour TV standard before Thomson became involved. The Soviets developed two further systems, mixing concepts from PAL and SECAM, known as TRIPAL and NIIR, that never went beyond tests. In 1993, an evolution of PAL aimed to improve and enhance format by allowing 16:9 aspect ratio broadcasts, while remaining compatible with existing television receivers,
11753-647: The Representation of the People Act 1918 . After the war, Britain became a permanent member of the Executive Council of the League of Nations and received a mandate over a number of former German and Ottoman colonies. Under the leadership of David Lloyd George , the British Empire reached its greatest extent, covering a fifth of the world's land surface and a quarter of its population. By
11914-973: The Soviet Union formed in 1941, leading the Allies against the Axis powers . There were eventual hard-fought victories in the Battle of the Atlantic , the North Africa campaign and the Italian campaign . British forces played important roles in the Normandy landings of 1944 and the liberation of Europe . The British Army led the Burma campaign against Japan, and the British Pacific Fleet fought Japan at sea. British scientists contributed to
12075-511: The Western Front . The high fatalities of trench warfare caused the loss of much of a generation of men, with lasting social effects in the nation and a great disruption in the social order. Britain had suffered 2.5 million casualties and finished the war with a huge national debt. The consequences of the war persuaded the government to expand the right to vote in national and local elections to all adult men and most adult women with
12236-430: The back porch . The back porch is the portion of each scan line between the end (rising edge) of the horizontal sync pulse and the start of active video. It is used to restore the black level (300 mV) reference in analog video. In signal processing terms, it compensates for the fall time and settling time following the sync pulse. In color television systems such as PAL and NTSC, this period also includes
12397-471: The coastline paradox . It is connected to continental Europe by the Channel Tunnel , which at 31 miles (50 km) (24 miles (38 km) underwater) is the longest underwater tunnel in the world. The UK contains four terrestrial ecoregions: Celtic broadleaf forests , English Lowlands beech forests , North Atlantic moist mixed forests , and Caledonian conifer forests . The area of woodland in
12558-465: The colorburst signal. In the SECAM system, it contains the reference subcarrier for each consecutive color difference signal in order to set the zero-color reference. In some professional systems, particularly satellite links between locations, the digital audio is embedded within the line sync pulses of the video signal, to save the cost of renting a second channel. The name for this proprietary system
12719-534: The control grid in the electron gun of the CRT. This changes the intensity of the electron beam and therefore the brightness of the spot being scanned. Brightness and contrast controls determine the DC shift and amplification, respectively. A color signal conveys picture information for each of the red, green, and blue components of an image. However, these are not simply transmitted as three separate signals, because: such
12880-491: The largest protest in British history in opposition to the government led by Tony Blair . The Great Recession severely affected the UK economy. The Cameron–Clegg coalition government of 2010 introduced austerity measures intended to tackle the substantial public deficits. Studies have suggested that policy led to significant social disruption and suffering. A referendum on Scottish independence in 2014 resulted in
13041-640: The process of conversion , or have already converted transmission standards to DVB , ISDB or DTMB . The PAL designation continues to be used in some non-broadcast contexts, especially regarding console video games . PAL was adopted by most European countries, by several African countries, by Argentina , Brazil , Paraguay , Uruguay , and by most of Asia Pacific (including the Middle East and South Asia) . Countries in those regions that did not adopt PAL were France , Francophone Africa, several ex- Soviet states, Japan , South Korea , Liberia , Myanmar ,
13202-560: The " Pax Britannica " between 1815 and 1914. At its height in the 1920s, the British Empire encompassed almost a quarter of the world's landmass and population, and was the largest empire in history . However, its involvement in the First World War and the Second World War damaged Britain's economic power and a global wave of decolonisation led to the independence of most British colonies. The United Kingdom
13363-619: The 16th century and established the Church of England . Moreover, it defined a national identity for England and slowly, but profoundly, changed people's religious beliefs. Wales was fully incorporated into the Kingdom of England , and Ireland was constituted as a kingdom in personal union with the English crown. In what was to become Northern Ireland, the lands of the independent Catholic Gaelic nobility were confiscated and given to Protestant settlers from England and Scotland. In 1603,
13524-491: The 16th century in the annexation of Wales , the domination of Scotland , and the establishment of the British Empire . Over the course of the 17th century, the role of the British monarchy was reduced, particularly as a result of the English Civil War . In 1707, the Kingdom of England and the Kingdom of Scotland united under the Treaty of Union to create the Kingdom of Great Britain . The Acts of Union 1800 incorporated
13685-401: The 1713 Treaty of Utrecht, is a key military base . A referendum in 2002 on shared sovereignty with Spain was rejected by 98.97% of voters in the territory. Around the end of the 20th century, there were major changes to the governance of the UK with the establishment of devolved administrations for Scotland, Wales and Northern Ireland. The statutory incorporation followed acceptance of
13846-521: The 1970s, the Conservative government of the 1980s led by Margaret Thatcher initiated a radical policy of monetarism , deregulation, particularly of the financial sector (for example, the Big Bang in 1986) and labour markets, the sale of state-owned companies (privatisation), and the withdrawal of subsidies to others. In 1982, Argentina invaded the British territories of South Georgia and
14007-646: The 5th century) united with the Picts to create the Kingdom of Scotland in the 9th century. In 1066, the Normans invaded England from northern France. After conquering England , they seized large parts of Wales , conquered much of Ireland and were invited to settle in Scotland, bringing to each country feudalism on the Northern French model and Norman-French culture. The Anglo-Norman ruling class greatly influenced, but eventually assimilated with,
14168-700: The Brittonic area mainly to what was to become Wales , Cornwall and, until the latter stages of the Anglo-Saxon settlement, the Hen Ogledd (northern England and parts of southern Scotland). Most of the region settled by the Anglo-Saxons became unified as the Kingdom of England in the 10th century. Meanwhile, Gaelic speakers in north-west Britain (with connections to the north-east of Ireland and traditionally supposed to have migrated from there in
14329-830: The Manhattan Project whose task was to build an atomic weapon. Once built, it was decided, with British consent, to use the weapon against Japan. The UK was one of the Big Three powers (along with the US and the Soviet Union) who met to plan the post-war world ; it drafted the Declaration by United Nations with the United States and became one of the five permanent members of the United Nations Security Council . It worked closely with
14490-408: The NTSC and PAL color systems, U and V are transmitted by using quadrature amplitude modulation of a subcarrier. This kind of modulation applies two independent signals to one subcarrier, with the idea that both signals will be recovered independently at the receiving end. For NTSC, the subcarrier is at 3.58 MHz. For the PAL system it is at 4.43 MHz. The subcarrier itself is not included in
14651-411: The NTSC system. PAL's color encoding is similar to the NTSC systems. SECAM, though, uses a different modulation approach than PAL or NTSC. PAL had a late evolution called PALplus , allowing widescreen broadcasts while remaining fully compatible with existing PAL equipment. In principle, all three color encoding systems can be used with any scan line/frame rate combination. Therefore, in order to describe
14812-716: The Scottish electorate voting by 55.3 to 44.7% to remain part of the United Kingdom. In 2016, 51.9 per cent of voters in the United Kingdom voted to leave the European Union . The UK left the EU in 2020. On 1 May 2021, the EU–UK Trade and Cooperation Agreement came into force. The COVID-19 pandemic had a severe impact on the UK's economy , caused major disruptions to education and had far-reaching impacts on society and politics in 2020 and 2021. The United Kingdom
14973-405: The U and V axis) gating methods is called I/Q demodulation. Another much more popular off-axis scheme was the X/Z demodulation system. Further matrixing recovered the original U and V signals. This scheme was actually the most popular demodulator scheme throughout the 1960s. The above process uses the subcarrier. But as previously mentioned, it was deleted before transmission, and only the chroma
15134-484: The UK in 2023 is estimated to be 3.25 million hectares, which represents 13% of the total land area in the UK. Most of the United Kingdom has a temperate climate, with generally cool temperatures and plentiful rainfall all year round. The temperature varies with the seasons seldom dropping below 0 °C (32 °F ) or rising above 30 °C (86 °F). Some parts, away from the coast, of upland England, Wales, Northern Ireland and most of Scotland, experience
15295-961: The UK into lowland and upland areas. Lowland areas include Cornwall , the New Forest , the South Downs and the Norfolk Broads . Upland areas include the Lake District , the Pennines , the Yorkshire Dales , Exmoor , and Dartmoor . The main rivers and estuaries are the Thames , Severn , and the Humber . England's highest mountain is Scafell Pike , at 978 metres (3,209 ft) in the Lake District; its largest island
15456-402: The United Kingdom and that elsewhere "British government" is used at least as frequently as "United Kingdom government". The UK Permanent Committee on Geographical Names recognises "United Kingdom", "UK" and "U.K." as shortened and abbreviated geopolitical terms for the United Kingdom of Great Britain and Northern Ireland in its toponymic guidelines; it does not list "Britain" but notes that "it
15617-411: The United Kingdom is 1339.7 hours, which is just under 30% of the maximum possible. The hours of sunshine vary from 1200 to about 1580 hours per year, and since 1996 the UK has been and still is receiving above the 1981 to 2010 average hours of sunshine. Climate change has a serious impact on the country. A third of food price rise in 2023 is attributed to climate change. As of 2022, the United Kingdom
15778-400: The United Kingdom is a sovereign country, England, Scotland, Wales and Northern Ireland are also widely referred to as countries . The UK Prime Minister's website has used the phrase "countries within a country" to describe the United Kingdom. Some statistical summaries, such as those for the twelve NUTS 1 regions , refer to Scotland, Wales and Northern Ireland as "regions". Northern Ireland
15939-832: The United Kingdom is surrounded by the Atlantic Ocean , the North Sea , the English Channel , the Celtic Sea , and the Irish Sea . The United Kingdom had an estimated population of over 68.2 million people in 2023. The capital and largest city of both England and the United Kingdom is London , whose wider metropolitan area is the largest in Western Europe , with a population of 14.9 million. The cities of Edinburgh , Cardiff , and Belfast are
16100-436: The United Kingdom use several different terms to describe their national identity and may identify themselves as being British , English , Scottish , Welsh , Northern Irish , or Irish ; or as having a combination of different national identities. Settlement by Cro-Magnons of what was to become the United Kingdom occurred in waves beginning by about 30,000 years ago. The island has been continuously inhabited only since
16261-620: The United Kingdom. The 1928 Equal Franchise Act gave women electoral equality with men in national elections. Strikes in the mid-1920s culminated in the General Strike of 1926 . Britain had still not recovered from the effects of the First World War when the Great Depression (1929–1932) led to considerable unemployment and hardship in the old industrial areas, as well as political and social unrest with rising membership in communist and socialist parties. A coalition government
16422-640: The United States to establish the IMF , World Bank and NATO . The war left the UK severely weakened and financially dependent on the Marshall Plan , but it was spared the total war that devastated eastern Europe. In the immediate post-war years, the Labour government under Clement Attlee initiated a radical programme of reforms, which significantly impacted British society in the following decades . Major industries and public utilities were nationalised ,
16583-407: The Y signal) represents the approximate saturation of a color, and the chrominance phase against the subcarrier reference approximately represents the hue of the color. For particular test colors found in the test color bar pattern, exact amplitudes and phases are sometimes defined for test and troubleshooting purposes only. Due to the nature of the quadrature amplitude modulation process that created
16744-521: The acquisition and settlement of overseas colonies , particularly in North America and the Caribbean. Though previous attempts at uniting the two kingdoms within Great Britain in 1606, 1667, and 1689 had proved unsuccessful, the attempt initiated in 1705 led to the Treaty of Union of 1706 being agreed and ratified by both parliaments. On 1 May 1707, the Kingdom of Great Britain was formed,
16905-479: The alternating subcarrier phase to reduce phase errors, described as " PAL-D " for "delay", and " PAL-N " for "new" or " Chrominance Lock ". This excluded very basic PAL decoders that relied on the human eye to average out the odd/even line phase errors, and in the early 1970s some Japanese set manufacturers developed basic decoding systems to avoid paying royalties to Telefunken . These variations are known as " PAL-S " (for "simple" or "Volks-PAL"), operating without
17066-399: The audio carrier frequency and channel bandwidths. The variants are: Systems B and G are similar. System B specifies 7 MHz channel bandwidth, while System G specifies 8 MHz channel bandwidth. Australia and China used Systems B and D respectively for VHF and UHF channels. Similarly, Systems D and K are similar except for the bands they use: System D is only used on VHF, while System K
17227-435: The basic sound signal. In newer sets, this new carrier at the offset frequency was allowed to remain as intercarrier sound , and it was sent to an FM demodulator to recover the basic sound signal. One particular advantage of intercarrier sound is that when the front panel fine tuning knob is adjusted, the sound carrier frequency does not change with the tuning, but stays at the above-mentioned offset frequency. Consequently, it
17388-423: The beginning of the first line at the top of the screen. As it passes each point, the intensity of the beam is varied, varying the luminance of that point. A color television system is similar except there are three beams that scan together and an additional signal known as chrominance controls the color of the spot. When analog television was developed, no affordable technology for storing video signals existed;
17549-419: The brightness control signal ( luminance ) is fed to the cathode connections of the electron guns, and the color difference signals ( chrominance signals) are fed to the control grids connections. This simple CRT matrix mixing technique was replaced in later solid state designs of signal processing with the original matrixing method used in the 1954 and 1955 color TV receivers. Synchronizing pulses added to
17710-525: The chrominance information was added to the monochrome signals in a way that black and white televisions ignore. In this way backward compatibility was achieved. There are three standards for the way the additional color information can be encoded and transmitted. The first was the American NTSC system. The European and Australian PAL and the French and former Soviet Union SECAM standards were developed later and attempt to cure certain defects of
17871-436: The chrominance signal, at certain times, the signal represents only the U signal, and 70 nanoseconds (NTSC) later, it represents only the V signal. About 70 nanoseconds later still, -U, and another 70 nanoseconds, -V. So to extract U, a synchronous demodulator is utilized, which uses the subcarrier to briefly gate the chroma every 280 nanoseconds, so that the output is only a train of discrete pulses, each having an amplitude that
18032-542: The coast of the continental mainland . It comprises England , Scotland , Wales , and Northern Ireland . The UK includes the island of Great Britain , the north-eastern part of the island of Ireland , and most of the smaller islands within the British Isles , making up a total area of 94,354 square miles (244,376 km ). Northern Ireland shares a land border with the Republic of Ireland ; otherwise,
18193-411: The colour carrier is a result of 283.75 colour clock cycles per line plus a 25 Hz offset to avoid interferences. Since the line frequency (number of lines per second) is 15625 Hz (625 lines × 50 Hz ÷ 2), the colour carrier frequency calculates as follows: 4.43361875 MHz = 283.75 × 15625 Hz + 25 Hz. The frequency 50 Hz is the optional refresh frequency of
18354-415: The colour decoder circuitry to distinguish the phase of the R − Y ′ {\displaystyle R-Y'} vector which reverses every line. For PAL-B/G the signal has these characteristics. (Total horizontal sync time 12.05 μs) After 0.9 μs a 2.25 ± 0.23 μs colourburst of 10 ± 1 cycles is sent. Most rise/fall times are in 250 ± 50 ns range. Amplitude
18515-425: The combining process, the low-resolution portion of the Y signals cancel out, leaving R, G, and B signals able to render a low-resolution image in full color. However, the higher resolution portions of the Y signals do not cancel out, and so are equally present in R, G, and B, producing the higher-resolution image detail in monochrome, although it appears to the human eye as a full-color and full-resolution picture. In
18676-486: The composite video format used by analog video devices such as VCRs or CCTV cameras . To ensure good linearity and thus fidelity, consistent with affordable manufacturing costs of transmitters and receivers, the video carrier is never modulated to the extent that it is shut off altogether. When intercarrier sound was introduced later in 1948, not completely shutting off the carrier had the side effect of allowing intercarrier sound to be economically implemented. Each line of
18837-736: The decades-long process of European integration , the UK was a founding member of the Western European Union , established with the London and Paris Conferences in 1954. In 1960 the UK was one of the seven founding members of the European Free Trade Association (EFTA), but in 1973 it left to join the European Communities (EC). In a 1975 referendum 67% voted to stay in it. When the EC became
18998-634: The development of the cathode-ray tube (CRT), 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 closely spaced scan lines and much higher image resolution. Also, far less maintenance was required of an all-electronic system compared to a mechanical spinning disc system. All-electronic systems became popular with households after World War II . Broadcasters of analog television encode their signal using different systems. The official systems of transmission were defined by
19159-507: The digital signals ( 576i or 480i ) to the analog standards to assure compatibility. CCIR 625/50 and EIA 525/60 are the proper names for these (line count and field rate) standards; PAL and NTSC on the other hand are methods of encoding colour information in the signal. "PAL-D", "PAL-N", "PAL-H" and "PAL-K" designations on this section describe PAL decoding methods and are unrelated to broadcast systems with similar names. The Telefunken licence covered any decoding method that relied on
19320-503: 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. Camera systems used similar spinning discs and required intensely bright illumination of the subject for the light detector to work. The reproduced images from these mechanical systems were dim, very low resolution and flickered severely. Analog television did not begin in earnest as an industry until
19481-417: The displayed image is transmitted using a signal as shown above. The same basic format (with minor differences mainly related to timing and the encoding of color) is used for PAL, NTSC , and SECAM television systems. A monochrome signal is identical to a color one, with the exception that the elements shown in color in the diagram (the colorburst , and the chrominance signal) are not present. The front porch
19642-483: The eastern parts are the driest. Atlantic currents, warmed by the Gulf Stream , bring mild winters, especially in the west where winters are wet and even more so over high ground. Summers are warmest in the southeast of England and coolest in the north. Heavy snowfall can occur in winter and early spring on high ground, and occasionally settles to great depth away from the hills. The average total annual sunshine in
19803-433: The equivalent hue changes of NTSC. A minor drawback is that the vertical colour resolution is poorer than the NTSC system's, but since the human eye also has a colour resolution that is much lower than its brightness resolution, this effect is not visible. In any case, NTSC, PAL, and SECAM all have chrominance bandwidth (horizontal colour detail) reduced greatly compared to the luma signal. The 4.43361875 MHz frequency of
19964-594: The first year, Britain and its Empire continued the war against Germany. Churchill engaged industry, scientists and engineers to support the government and the military in the prosecution of the war effort. In 1940, the Royal Air Force defeated the German Luftwaffe in the Battle of Britain . Urban areas suffered heavy bombing during the Blitz . The Grand Alliance of Britain, the United States and
20125-587: The formal control it exerted over its own colonies, British dominance of much of world trade meant that it effectively controlled the economies of regions such as East Asia and Latin America . Throughout the Victorian era , political attitudes favoured free trade and laissez-faire policies. Beginning with the Great Reform Act in 1832, Parliament gradually widened the voting franchise , with
20286-762: The global hegemon and adopted the role of global policeman. From 1853 to 1856, Britain took part in the Crimean War , allied with the Ottoman Empire against Tsarist Russia , participating in the naval battles of the Baltic Sea known as the Åland War in the Gulf of Bothnia and the Gulf of Finland , among others. Following the Indian Rebellion in 1857 , the British government led by Lord Palmerston assumed direct rule over India . Alongside
20447-403: The kingdoms of England, Scotland and Ireland were united in a personal union when James VI, King of Scots , inherited the crowns of England and Ireland and moved his court from Edinburgh to London; each country nevertheless remained a separate political entity and retained its separate political, legal, and religious institutions. In the mid-17th century, all three kingdoms were involved in
20608-408: The last retreat of the ice around 11,500 years ago. By the end of the region's prehistoric period , the population is thought to have belonged largely to a culture termed Insular Celtic , comprising Brittonic Britain and Gaelic Ireland . The Roman conquest , beginning in 43 AD, and the 400-year rule of southern Britain , was followed by an invasion by Germanic Anglo-Saxon settlers, reducing
20769-530: The local cultures. Subsequent medieval English kings completed the conquest of Wales and tried unsuccessfully to annex Scotland . Asserting its independence in the 1320 Declaration of Arbroath , Scotland maintained its independence thereafter, albeit in near-constant conflict with England . In 1215 the Magna Carta was the first document to state that no government was above the law, that citizens have rights protecting them and that they were entitled to
20930-526: The lower bandwidth requirements of compressed digital signals , beginning just after the year 2000, a digital television transition is proceeding in most countries of the world, with different deadlines for the cessation of analog broadcasts. Several countries have made the switch already, with the remaining countries still in progress mostly in Africa, Asia, and South America. The earliest systems of analog television were mechanical television systems that used spinning disks with patterns of holes punched into
21091-401: The luminance signal had to be generated and transmitted at the same time at which it is displayed on the CRT. It was therefore essential to keep the raster scanning in the camera (or other device for producing the signal) in exact synchronization with the scanning in the television. The physics of the CRT require that a finite time interval be allowed for the spot to move back to the start of
21252-618: The major part of the British Isles archipelago and includes the island of Great Britain, the north-eastern one-sixth of the island of Ireland and some smaller surrounding islands. It lies between the North Atlantic Ocean and the North Sea with the southeast coast coming within 22 miles (35 km) of the coast of northern France, from which it is separated by the English Channel . The Royal Greenwich Observatory in London
21413-674: The mid-1920s, most of the British population could listen to BBC radio programmes. Experimental television broadcasts began in 1929 and the first scheduled BBC Television Service commenced in 1936. The rise of Irish nationalism , and disputes within Ireland over the terms of Irish Home Rule , led eventually to the partition of the island in 1921. A period of conflict in what is now Northern Ireland occurred from June 1920 until June 1922. The Irish Free State became independent, initially with Dominion status in 1922, and unambiguously independent in 1931 . Northern Ireland remained part of
21574-435: The modulated signal ( suppressed carrier ), it is the subcarrier sidebands that carry the U and V information. The usual reason for using suppressed carrier is that it saves on transmitter power. In this application a more important advantage is that the color signal disappears entirely in black and white scenes. The subcarrier is within the bandwidth of the main luminance signal and consequently can cause undesirable artifacts on
21735-432: The monitor to be able to create an illusion of motion, while 625 lines means the vertical lines or resolution that the PAL system supports. The original colour carrier is required by the colour decoder to recreate the colour difference signals. Since the carrier is not transmitted with the video information it has to be generated locally in the receiver. In order that the phase of this locally generated signal can match
21896-400: The monochrome luma signal, with the three RGB colour channels mixed down onto two, U {\displaystyle U} and V {\displaystyle V} . Like NTSC, PAL uses a quadrature amplitude modulated subcarrier carrying the chrominance information added to the luma video signal to form a composite video baseband signal. The frequency of this subcarrier
22057-688: The national capitals of Scotland, Wales, and Northern Ireland, respectively. The lands of the UK have been inhabited continuously since the Neolithic . In AD 43 the Roman conquest of Britain began; the Roman departure was followed by Anglo-Saxon settlement . In 1066, the Normans conquered England . With the end of the Wars of the Roses the English state stabilised and began to grow in power, resulting by
22218-410: The negative side-effect of causing image smearing and blurring when there is rapid on-screen motion occurring. The maximum frame rate depends on the bandwidth of the electronics and the transmission system, and the number of horizontal scan lines in the image. A frame rate of 25 or 30 hertz is a satisfactory compromise, while the process of interlacing two video fields of the picture per frame
22379-451: The next line ( horizontal retrace ) or the start of the screen ( vertical retrace ). The timing of the luminance signal must allow for this. The human eye has a characteristic called phi phenomenon . Quickly displaying successive scan images creates the illusion of smooth motion. Flickering of the image can be partially solved using a long persistence phosphor coating on the CRT so that successive images fade slowly. However, slow phosphor has
22540-491: The next year. Telefunken PALcolour 708T was the first PAL commercial TV set. It was followed by Loewe -Farbfernseher S 920 and F 900 . Telefunken was later bought by the French electronics manufacturer Thomson . Thomson also bought the Compagnie Générale de Télévision where Henri de France developed SECAM, the first European Standard for colour television. Thomson, now called Technicolour SA, also owns
22701-452: The phase of the signal on each successive line, and averaging the results over pairs of lines. This process is achieved by the use of a 1H (where H = horizontal scan frequency) duration delay line. Phase shift errors between successive lines are therefore canceled out and the wanted signal amplitude is increased when the two in-phase ( coincident ) signals are re-combined. NTSC is more spectrum efficient than PAL, giving more picture detail for
22862-488: The picture, all the more noticeable in black and white receivers. A small sample of the subcarrier, the colorburst , is included in the horizontal blanking portion, which is not visible on the screen. This is necessary to give the receiver a phase reference for the modulated signal. Under quadrature amplitude modulation the modulated chrominance signal changes phase as compared to its subcarrier and also changes amplitude. The chrominance amplitude (when considered together with
23023-739: The possible combinations exist. NTSC is only used with system M, even though there were experiments with NTSC-A ( 405 line ) in the UK and NTSC-N (625 line) in part of South America. PAL is used with a variety of 625-line standards (B, G, D, K, I, N) but also with the North American 525-line standard, accordingly named PAL-M . Likewise, SECAM is used with a variety of 625-line standards. For this reason, many people refer to any 625/25 type signal as PAL and to any 525/30 signal as NTSC , even when referring to digital signals; for example, on DVD-Video , which does not contain any analog color encoding, and thus no PAL or NTSC signals at all. Although
23184-468: The received signal, caused sometimes by multipath, but mostly by poor implementation at the studio end. With the advent of solid-state receivers, cable TV, and digital studio equipment for conversion to an over-the-air analog signal, these NTSC problems have been largely fixed, leaving operator error at the studio end as the sole color rendition weakness of the NTSC system. In any case, the PAL D (delay) system mostly corrects these kinds of errors by reversing
23345-432: The rendering of colors in this way is the goal of both monochrome film and television systems, the Y signal is ideal for transmission as the luminance signal. This ensures a monochrome receiver will display a correct picture in black and white, where a given color is reproduced by a shade of gray that correctly reflects how light or dark the original color is. The U and V signals are color difference signals. The U signal
23506-504: The rest of Europe, royal absolutism would not prevail, and a professed Catholic could never accede to the throne. The British constitution would develop on the basis of constitutional monarchy and the parliamentary system . With the founding of the Royal Society in 1660, science was greatly encouraged. During this period, particularly in England, the development of naval power and the interest in voyages of discovery led to
23667-406: The result of the Acts of Union 1707 between the Kingdom of England and Kingdom of Scotland . In the 18th century, cabinet government developed under Robert Walpole , in practice the first prime minister (1721–1742). A series of Jacobite uprisings sought to remove the Protestant House of Hanover from the throne and restore the Catholic House of Stuart . The Jacobites were finally defeated at
23828-513: The same, resulting in the different sound carrier. Instead, other European countries have changed completely from SECAM-D/K to PAL-B/G. The PAL-N system has a different sound carrier, and also a different colour subcarrier, and decoding on incompatible PAL systems results in a black-and-white image without sound. The PAL-M system has a different sound carrier and a different colour subcarrier, and does not use 625 lines or 50 frames/second. This would result in no video or audio at all when viewing
23989-415: The sound is transmitted with frequency modulation at a frequency at a fixed offset (typically 4.5 to 6 MHz) from the picture signal. The channel frequencies chosen represent a compromise between allowing enough bandwidth for video (and hence satisfactory picture resolution), and allowing enough channels to be packed into the available frequency band. In practice a technique called vestigial sideband
24150-486: The technical details of each format). This ensures video interoperability. However, as some of these standards ( B/G/H , I and D/K ) use different sound carriers (5.5 MHz, 6.0 MHz and 6.5 MHz respectively), it may result in a video image without audio when viewing a signal broadcast over the air or cable. Some countries in Eastern Europe which formerly used SECAM with systems D and K have switched to PAL while leaving other aspects of their video system
24311-434: The three color-difference signals, (R-Y), (B-Y), and (G-Y). The R, G, and B signals in the receiver needed for the display device (CRT, Plasma display, or LCD display) are electronically derived by matrixing as follows: R is the additive combination of (R-Y) with Y, G is the additive combination of (G-Y) with Y, and B is the additive combination of (B-Y) with Y. All of this is accomplished electronically. It can be seen that in
24472-405: The transmission of the signal by cancelling them out, at the expense of vertical frame colour resolution. Lines where the colour phase is reversed compared to NTSC are often called PAL or phase-alternation lines, which justifies one of the expansions of the acronym, while the other lines are called NTSC lines. Early PAL receivers relied on the human eye to do that cancelling; however, this resulted in
24633-412: The transmitted information, a 10 cycle burst of colour subcarrier is added to the video signal shortly after the line sync pulse, but before the picture information, during the so-called back porch . This colour burst is not actually in phase with the original colour subcarrier, but leads it by 45 degrees on the odd lines and lags it by 45 degrees on the even lines. This swinging burst enables
24794-420: The video signal at the end of every scan line and video frame ensure that the sweep oscillators in the receiver remain locked in step with the transmitted signal so that the image can be reconstructed on the receiver screen. United Kingdom The United Kingdom of Great Britain and Northern Ireland , commonly known as the United Kingdom ( UK ) or Britain , is a country in Northwestern Europe , off
24955-482: Was adopted by Sony on their 1970s Trinitron sets ( KV-1300UB to KV-1330UB ), and came in two versions: " PAL-H " and " PAL-K " (averaging over multiple lines). It effectively treated PAL as NTSC, suffering from hue errors and other problems inherent in NTSC and required the addition of a manual hue control. Most PAL systems encode the colour information using a variant of the Y'UV colour space. Y ′ {\displaystyle Y'} comprises
25116-416: Was chosen as the defining point of the Prime Meridian at the International Meridian Conference in 1884. The United Kingdom lies between latitudes 49° and 61° N , and longitudes 9° W and 2° E . Northern Ireland shares a 224-mile (360 km) land boundary with the Republic of Ireland. The coastline of Great Britain is 11,073 miles (17,820 km) long, though measurements can vary greatly due to
25277-461: Was developed by Walter Bruch at Telefunken in Hanover, West Germany , with important input from Gerhard Mahler [ de ] . The format was patented by Telefunken in December 1962, citing Bruch as inventor, and unveiled to members of the European Broadcasting Union (EBU) on 3 January 1963. When asked why the system was named "PAL" and not "Bruch" the inventor answered that a "Bruch system" would probably not have sold very well ("Bruch"
25438-404: Was formed in 1931. Nonetheless, "Britain was a very wealthy country, formidable in arms, ruthless in pursuit of its interests and sitting at the heart of a global production system." After Nazi Germany invaded Poland in 1939, Britain entered the Second World War . Winston Churchill became prime minister and head of a coalition government in 1940. Despite the defeat of its European allies in
25599-424: Was introduced. Named PALplus , it was defined by ITU recommendation BT.1197-1. It was developed at the University of Dortmund in Germany , in cooperation with German terrestrial broadcasters and European and Japanese manufacturers. Adoption was limited to European countries. With the introduction of digital broadcasts and signal sources (ex: DVDs , game consoles), the term PAL was used imprecisely to refer to
25760-407: Was simply "Great Britain". The Acts of Union 1800 formed the United Kingdom of Great Britain and Ireland . Following the partition of Ireland and the independence of the Irish Free State in 1922, which left Northern Ireland as the only part of the island of Ireland within the United Kingdom, the name was changed in 1927 to the "United Kingdom of Great Britain and Northern Ireland". Although
25921-432: Was the first country in the world to use an approved COVID-19 vaccine , developing its own vaccine through a collaboration between Oxford University and AstraZeneca , which allowed the UK's vaccine rollout to be among the fastest in the world. The total area of the United Kingdom is approximately 94,354 square miles (244,376 km ), with a land area of 93,723 square miles (242,741 km ). The country occupies
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