CCIR System B (originally known as the "Gerber Standard" [1] [2] [3] [4] ) was the 625-line VHF analog broadcast television system which at its peak was adopted by more than one hundred countries, either with PAL or SECAM colour. [5] It is usually associated with CCIR System G for UHF broadcasts.
SystemB was the first internationally accepted 625-line broadcasting standard in the world. A first 625-line system with a 8 MHz channel bandwidth was proposed at the CCIR Conference in Stockholm in July 1948 (based on 1946-48 studies in the Soviet Union [6] by Mark Krivosheev [7] [8] [9] [10] [11] [12] [13] ). [3] At a CCIR Geneva meeting in July 1950 Dr. Gerber (a Swiss engineer), proposed a modified 625-lines system with a 7 MHz channel bandwidth (based on work by Telefunken and Walter Bruch), with the support of Belgium, Denmark, Italy, Netherlands, Sweden, Switzerland. [6] Known as the "Gerber-norm", it was eventually approved along with four other broadcast standards on the next formal CCIR meeting in May 1951 in Geneva. [6] [14]
It is mostly replaced across Western Europe, former Yugoslavia, parts of Asia and Africa by digital broadcasting.
The system was developed for VHF (also known as VHF-3) band (part of RF band lower than 300 MHz.) Some of the most important specs are listed below. [15]
A frame is the total picture. The frame rate is the number of pictures displayed in one second. But each frame is actually scanned twice interleaving odd and even lines. Each scan is known as a field (odd and even fields.) So field rate is twice the frame rate. In each frame there are 625 lines (or 312.5 lines in a field.) So line rate (line frequency) is 625 times the frame frequency or 625•25=15625 Hz.
The video bandwidth is 5.0 MHz. The video signal modulates the carrier by amplitude modulation. But a portion of the lower side band is suppressed. This technique is known as vestigial side band modulation (AC3). The polarity of modulation is negative, meaning that an increase in the instantaneous brightness of the video signal results in a decrease in RF power and vice versa. Specifically, the sync pulses (being "blacker than black") result in maximum power from the transmitter.
The primary audio signal is modulated by frequency modulation with a preemphasis time constant of = 50 μs. The deviation for a 1.0 kHz. AF signal is 50 kHz.
The separation between the primary audio FM subcarrier and the video carrier is 5.5 MHz.
The total RF bandwidth of System B (as originally designed with its single FM audio subcarrier) was 6.5 MHz, allowing System B to be transmitted in the 7.0 MHz wide channels specified for television in the VHF bands with an ample 500 kHz guard zone between channels. [18]
In specs, sometimes, other parameters such as vestigial sideband characteristics and gamma correction of the display device are also given.
System B has variously been used with both the PAL or SECAM colour systems. It could have been used with a 625-line variant of the NTSC color system, but apart from possible technical tests in the 1950s, this has never been done officially.
When used with PAL, the colour subcarrier is 4.43361875 MHz and the sidebands of the PAL signal have to be truncated on the high-frequency side at +570 kHz (matching the rolloff of the luminance signal at +5.0 MHz). On the low-frequency side, the full 1.3 MHz sideband is radiated. (This behaviour would cause massive U/V crosstalk in the NTSC system, but delay-line PAL hides such artefacts.)
When used with SECAM, the 'R' lines' carrier is at 4.40625 MHz deviating from +350±18 kHz to -506±25 kHz. The 'B' lines' carrier is at 4.250 MHz deviating +506±25 kHz to -350±18 kHz.
Neither colour encoding system has any effect on the bandwidth of system B as a whole.
Enhancements have been made to the specification of System B's audio capabilities over the years. The introduction of Zweikanalton in 1981 allowed for stereo sound or twin monophonic audio tracks (possibly in different languages for instance). This was implemented by adding a second FM audio subcarrier at +5.74 MHz. Alternatively, starting in the late 1980s and early 1990s it became possible to replace the second audio FM subcarrier with a digital signal carrying NICAM sound. Either of these extensions to audio capability have eaten into the guard band between channels. Zweiton uses an extra 150 kHz. The alternative NICAM system uses an extra 500 kHz, and needs to be spaced further from the primary audio subcarrier, thus System B with NICAM has only 150 kHz guard zones between channels.
The European 41-68 MHz Band I television allocation was agreed at the 1947 ITU (International Telecommunication Union) conference in 1947, and the first European channel plan (i.e. the use of channels E2 - E4) was agreed in 1952 at the ITU conference in Stockholm. The extension to VHF Band III (i.e. Channels E5 - E12) was also agreed in the 1950s.
Since then, the System B specification has been used with slightly different broadcast frequencies in many other countries.
Channel | Channel limits (MHz) | Vision carrier frequency (MHz) | Main audio carrier frequency (MHz) |
---|---|---|---|
E1 † | 40.00 - 47.00 | 41.25 | 46.75 |
E1A † | 41.00 - 48.00 | 42.25 | 47.75 |
E2 § | 47.00 - 54.00 | 48.25 | 53.75 |
E2A § | 48.25 - 55.50 | 49.75 | 55.25 |
E3 | 54.00 - 61.00 | 55.25 | 60.75 |
E4 | 61.00 - 68.00 | 62.25 | 67.75 |
E4A | 81.00 - 88.00 | 82.25 | 87.75 |
† Channel 1 was allocated, but never used.
§ Not used in the former East Germany
Channel | Channel limits (MHz) | Vision carrier frequency (MHz) | Main audio carrier frequency (MHz) |
---|---|---|---|
E5 | 174.00 - 181.00 | 175.25 | 180.75 |
E6 | 181.00 - 188.00 | 182.25 | 187.75 |
E7 | 188.00 - 195.00 | 189.25 | 194.75 |
E8 | 195.00 - 202.00 | 196.25 | 201.75 |
E9 | 202.00 - 209.00 | 203.25 | 208.75 |
E10 | 209.00 - 216.00 | 210.25 | 215.75 |
E11 | 216.00 - 223.00 | 217.25 | 222.75 |
E12 | 223.00 - 230.00 | 224.25 | 229.75 |
Channel | Channel limits (MHz) | Vision carrier frequency (MHz) | Main audio carrier frequency (MHz) |
---|---|---|---|
1 | 58.00 - 65.00 | 59.25 | 64.75 |
Channel | Channel limits (MHz) | Vision carrier frequency (MHz) | Main audio carrier frequency (MHz) |
---|---|---|---|
2 | 144.00 - 151.00 | 145.25 | 150.75 |
3 | 154.00 - 161.00 | 155.25 | 160.75 |
E5 | 174.00 - 181.00 | 175.25 | 180.75 |
E6 | 181.00 - 188.00 | 182.25 | 187.75 |
E8 | 195.00 - 202.00 | 196.25 | 201.75 |
E11 | 216.00 - 223.00 | 217.25 | 222.75 |
Transmitters were operational on the above channels in 1959. During the 1960s, channels 1 to 3 were deleted and channels E3 to E12 adopted, bringing East Germany into line with the channel allocations used in the West.
Italian channel-spacings were erratic. System B is no longer in use in Italy, the switchover to DVB-T having been completed 4 July 2012.
Channel | Channel limits (MHz) | Vision carrier frequency (MHz) | Audio carrier frequency (MHz) |
---|---|---|---|
IA | 52.50 - 59.50 | 53.75 | 59.25 |
IB | 61.00 - 68.00 | 62.25 | 67.75 |
IC [lower-alpha 1] | 81.00 - 88.00 | 82.25 | 87.75 |
Note: Band I is no longer used for television in Italy.
Channel | Channel limits (MHz) | Vision carrier frequency (MHz) | Audio carrier frequency (MHz) |
---|---|---|---|
ID [lower-alpha 1] | 174.00 - 181.00 | 175.25 | 180.75 |
IE | 182.50 - 189.50 | 183.75 | 189.25 |
IF | 191.00 - 198.00 | 192.25 | 197.75 |
IG | 200.00 - 207.00 | 201.25 | 206.75 |
IH [lower-alpha 2] | 209.00 - 216.00 | 210.25 | 215.75 |
IH1 [lower-alpha 3] | 216.00 - 223.00 | 217.25 | 222.75 |
Note: Unusually for Europe, Band III is used for DVB-T in Italy. At digital switchover time, Italy took the opportunity to discontinue their erratic System B frequencies, and the digital channels (known as Ch5 through Ch12) are regularly-spaced every 7.0 MHz from 177.5 MHz (and identical to Germany's Band III DVB-T bandplan).
Australia were unique in the world by their use of Band II for television broadcasting.
Channel | Channel limits (MHz) | Vision carrier frequency (MHz) | Main audio carrier frequency (MHz) |
---|---|---|---|
D0 | 45.00 - 52.00 | 46.25 | 51.75 |
D1 | 56.00 - 63.00 | 57.25 | 62.75 |
D2 | 63.00 - 70.00 | 64.25 | 69.75 |
Channel | Channel limits (MHz) | Vision carrier frequency (MHz) | Main audio carrier frequency (MHz) |
---|---|---|---|
D3 | 85.00 - 92.00 | 86.25 | 91.75 |
D4 | 94.00 - 101.00 | 95.25 | 100.75 |
D5 | 101.00 - 108.00 | 102.25 | 107.75 |
D5A | 137.00 - 144.00 | 138.25 | 143.75 |
Channel | Channel limits (MHz) | Vision carrier frequency (MHz) | Main audio carrier frequency (MHz) |
---|---|---|---|
D6 | 174.00 - 181.00 | 175.25 | 180.75 |
D7 | 181.00 - 188.00 | 182.25 | 194.75 |
D8 | 188.00 - 195.00 | 189.25 | 194.75 |
D9 | 195.00 - 202.00 | 196.25 | 201.75 |
D10 | 208.00 - 215.00 | 209.25 | 214.75 |
D11 | 215.00 - 222.00 | 216.25 | 221.75 |
Channel | Channel limits (MHz) | Vision carrier frequency (MHz) | Main audio carrier frequency (MHz) |
---|---|---|---|
D0 | 45.00 - 52.00 | 46.25 | 51.75 |
D1 | 56.00 - 63.00 | 57.25 | 62.75 |
D2 | 63.00 - 70.00 | 64.25 | 69.75 |
Channel | Channel limits (MHz) | Vision carrier frequency (MHz) | Main audio carrier frequency (MHz) |
---|---|---|---|
D3 ‡ | 85.00 - 92.00 | 86.25 | 91.75 |
D4 ‡ | 94.00 - 101.00 | 95.25 | 100.75 |
D5 ‡ | 101.00 - 108.00 | 102.25 | 107.75 |
D5A | 137.00 - 144.00 | 138.25 | 143.75 |
‡ Channels 3, 4 and 5 were scheduled to be cleared during 1993–96 to make way for FM radio stations in Band II. This clearance action took much longer than was anticipated, and as a result, many stations on channel 3 still remain, along with a few on 4 and 5.
Channel | Channel limits (MHz) | Vision carrier frequency (MHz) | Main audio carrier frequency (MHz) |
---|---|---|---|
D6 | 174.00 - 181.00 | 175.25 | 180.75 |
D7 | 181.00 - 188.00 | 182.25 | 194.75 |
D8 | 188.00 - 195.00 | 189.25 | 194.75 |
D9 | 195.00 - 202.00 | 196.25 | 201.75 |
D9A ♦ | 202.00 - 209.00 | 203.25 | 208.75 |
D10 ‡ | 209.00 - 216.00 | 210.25 | 215.75 |
D11 ‡ | 216.00 - 223.00 | 217.25 | 222.75 |
D12 ♦ | 223.00 - 230.00 | 224.25 | 229.75 |
♦ New channel allocations from 1993.
‡ Channels 10 and 11 were shifted up in frequency by 1 MHz to make room for channel 9A. The frequencies of existing stations did not change; only new ones used the new allocations. Digital multiplexes on channels 10 and 11 are using the new channel boundaries.
Australia is nearly unique in the world for their use of 7 MHz channel-spacing (and therefore System B) on UHF.
Channel | Channel limits (MHz) | Vision carrier frequency (MHz) | Main audio carrier frequency (MHz) |
---|---|---|---|
D28 | 526.00 - 533.00 | 527.25 | 532.75 |
D29 | 533.00 - 540.00 | 534.25 | 539.75 |
D30 | 540.00 - 547.00 | 541.25 | 546.75 |
D31 | 547.00 - 554.00 | 548.25 | 553.75 |
D32 | 554.00 - 561.00 | 555.25 | 560.75 |
D33 | 561.00 - 568.00 | 562.25 | 567.75 |
D34 | 568.00 - 575.00 | 569.25 | 574.75 |
D35 | 575.00 - 582.00 | 576.25 | 581.75 |
D36 | 582.00 - 589.00 | 583.25 | 588.75 |
D37 | 589.00 - 596.00 | 590.25 | 595.75 |
D38 | 596.00 - 603.00 | 597.25 | 602.75 |
D39 | 603.00 - 610.00 | 604.25 | 609.75 |
D40 | 610.00 - 617.00 | 611.25 | 616.75 |
D41 | 617.00 - 624.00 | 618.25 | 623.75 |
D42 | 624.00 - 631.00 | 625.25 | 630.75 |
D43 | 631.00 - 638.00 | 632.25 | 637.75 |
D44 | 638.00 - 645.00 | 639.25 | 644.75 |
D45 | 645.00 - 652.00 | 646.25 | 651.75 |
D46 | 652.00 - 659.00 | 653.25 | 658.75 |
D47 | 659.00 - 666.00 | 660.25 | 665.75 |
D48 | 666.00 - 673.00 | 667.25 | 672.75 |
D49 | 673.00 - 680.00 | 674.25 | 679.75 |
D50 | 680.00 - 687.00 | 681.25 | 686.75 |
D51 | 687.00 - 694.00 | 688.25 | 693.75 |
D52 | 694.00 - 701.00 | 695.25 | 700.75 |
D53 | 701.00 - 708.00 | 702.25 | 707.75 |
D54 | 708.00 - 715.00 | 709.25 | 714.75 |
D55 | 715.00 - 722.00 | 716.25 | 721.75 |
D56 | 722.00 - 729.00 | 723.25 | 728.75 |
D57 | 729.00 - 736.00 | 730.25 | 735.75 |
D58 | 736.00 - 743.00 | 737.25 | 742.75 |
D59 | 743.00 - 750.00 | 744.25 | 749.75 |
D60 | 750.00 - 757.00 | 751.25 | 756.75 |
D61 | 757.00 - 764.00 | 758.25 | 763.75 |
D62 | 764.00 - 771.00 | 765.25 | 770.75 |
D63 | 771.00 - 778.00 | 772.25 | 777.75 |
D64 | 778.00 - 785.00 | 779.25 | 784.75 |
D65 | 785.00 - 792.00 | 786.25 | 791.75 |
D66 | 792.00 - 799.00 | 793.25 | 798.75 |
D67 | 799.00 - 806.00 | 800.25 | 805.75 |
D68 | 806.00 - 813.00 | 807.25 | 812.75 |
D69 | 813.00 - 820.00 | 814.25 | 819.75 |
Channel | Channel limits (MHz) | Vision carrier frequency (MHz) | Main audio carrier frequency (MHz) |
---|---|---|---|
G1A | 43.00 - 50.00 | 44.25 | 49.75 |
G1 | 44.00 - 51.00 | 45.25 | 50.75 |
G2 | 54.00 - 61.00 | 55.25 | 60.75 |
G3 | 61.00 - 68.00 | 62.25 | 67.75 |
Channel | Channel limits (MHz) | Vision carrier frequency (MHz) | Main audio carrier frequency (MHz) |
---|---|---|---|
G4 | 174.00 - 181.00 | 175.25 | 180.75 |
G5 | 181.00 - 188.00 | 182.25 | 187.75 |
G6 | 188.00 - 195.00 | 189.25 | 194.75 |
G7 | 195.00 - 202.00 | 196.25 | 201.75 |
G8 | 202.00 - 209.00 | 203.25 | 208.75 |
G9 | 209.00 - 216.00 | 210.25 | 215.75 |
G10 † | 216.00 - 223.00 | 217.25 | 222.75 |
G11 ‡ | 223.00 - 230.00 | 224.25 | 229.75 |
† Added for New Zealand in the 1980s.
‡ Added for New Zealand in the 1990s.
Note: The Band III frequencies are the same as Australia. Channel G1A is only used in Indonesia.
Channel | Channel limits (MHz) | Vision carrier frequency (MHz) | Main audio carrier frequency (MHz) |
---|---|---|---|
M4 | 162.00 - 169.00 | 163.25 | 168.75 |
M5 | 170.00 - 177.00 | 171.25 | 176.75 |
M6 | 178.00 - 185.00 | 179.25 | 184.75 |
M7 | 186.00 - 193.00 | 187.25 | 192.75 |
M8 | 194.00 - 201.00 | 195.25 | 200.75 |
M9 | 202.00 - 209.00 | 203.25 | 208.75 |
M10 | 210.00 - 217.00 | 211.25 | 216.75 |
When the UHF bands came into use in the early 1960s, two variants of System B began to be used on those frequencies.
In most countries, the channels on the UHF bands are 8 MHz wide, but in most system B countries transmissions on the UHF channels still use system B specifications, the only difference being that the guard band between the channels is 1.0 MHz wider than for System B. That system for the UHF bands is known as System G and all RF specifications given above (apart from the guard band width) also apply to system G. Exceptions to this would seem to be Australia, Brunei and Tanzania where the UHF channels are 7 MHz wide, and system B is used on UHF just as it is on VHF.
A few countries (Belgium, several of the Balkan states and Malta) use another variant of system B on UHF which is known as System H. System H is similar to system G but the lower (vestigial) side band is 500 kHz wider. This makes much better use of the 8.0 MHz channels of the UHF bands (though whether any system B/H televisions actually made use of the extra bandwidth is not known).
Analog television 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.
NTSC is the first American standard for analog television, published in 1941. In 1961, it was assigned the designation System M. It is also known as EIA standard 170.
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 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.
SECAM, also written SÉCAM, is an analog color television system that was used in France, Russia and some other countries or territories of Europe and Africa. It was one of three major analog color television standards, the others being PAL and NTSC. Like PAL, a SECAM picture is also made up of 625 interlaced lines and is displayed at a rate of 25 frames per second. However, due to the way SECAM processes color information, it is not compatible with the PAL video format standard. SECAM video is composite video because the luminance and chrominance are transmitted together as one signal.
Broadcasttelevision systems are the encoding or formatting systems for the transmission and reception of terrestrial television signals.
The 405-line monochrome analogue television broadcasting system was the first fully electronic television system to be used in regular broadcasting. The number of television lines influences the image resolution, or quality of the picture.
Zweikanalton or A2 Stereo, is an analog television sound transmission system used in Germany, Austria, Australia, Switzerland, Netherlands and some other countries that use or used CCIR systems. South Korea utilized a modified version of Zweikanalton for the NTSC analog television standard. It relies on two separate FM carriers.
PAL-M is the analogue colour TV system used in Brazil since early 1972, making it the first South American country to broadcast in colour.
CCIR System M, sometimes called 525–line, monochrome NTSC, NTSC-M, or CCIR-M, is the analog broadcast television system approved by the FCC for use in the United States since July 1, 1941, replacing the 441-line TV system introduced in 1938. System M comprises a total of 525 interlaced lines of video, of which 486 contain the image information, at 30 frames per second. Video is amplitude modulated and audio is frequency modulated, with a total bandwidth of 6 MHz for each channel, including a guard band.
625-line is a late 1940s European analog standard-definition television resolution standard. It consists of a 625-line raster, with 576 lines carrying the visible image at 25 interlaced frames per second. It was eventually adopted by countries using 50 Hz utility frequency as regular TV broadcasts resumed after World War II. With the introduction of color television in the 1960s, it became associated with the PAL and SECAM analog color systems.
CCIR System G, also known as the "Gerber Standard", is an analog broadcast television system used in sixty countries around the world for UHF channels. System G is generally associated with System B for VHF.
CCIR System H is an analog broadcast television system used in Belgium, Bosnia and Herzegovina, Croatia, Malta, Slovenia and Liberia on UHF bands, paired with System B on VHF. It was associated with PAL colour.
CCIR System A was the 405-line analog broadcast television system adopted in the UK and Ireland. System A service started in 1936 and was discontinued in 1985.
CCIR System I is an analogue broadcast television system. It was first used in the Republic of Ireland starting in December 1961 as the 625-line broadcasting standard to be used on VHF Band I and Band III, sharing Band III with 405-line System A signals radiated in the north and east of the country. The Republic of Ireland has (slowly) extended its use of System I onto the UHF bands.
CCIR System E is an analog broadcast television system used in France and Monaco, associated with monochrome 819-line high resolution broadcasts. Transmissions started in 1949 and ended in 1985.
CCIR System N is an analog broadcast television system introduced in 1951 and adopted by Argentina, Paraguay and Uruguay, paired with the PAL color system (PAL-N) since 1980. It was also used briefly in Brazil and Venezuela.
CCIR System L is an analog broadcast television system used in France, Luxembourg, Monaco and Chausey. It was the last system to use positive video modulation and AM sound.
CCIR System K is an analog broadcast television system used in countries that adopted CCIR System D on VHF, and in Benin, Guinea, Republic of the Congo, Togo, Senegal, Burkina Faso, Burundi, Ivory Coast, Gabon, Comoros, Democratic Republic of the Congo, Madagascar, Mali, Nigeria, Réunion, Rwanda, Chad, Central African Republic, French Polynesia, New Caledonia, Wallis and Futuna, Guadeloupe, Martinique, Saint Pierre and Miquelon and French Guiana.
CCIR System D is an analog broadcast television system used in Bulgaria, Latvia, Lithuania, Poland, Romania, Slovakia, Czech Republic, Hungary, Albania and the People's Republic of China, Mongolia, Kyrgyzstan, North Korea, Tajikistan, Turkmenistan, Uzbekistan, Armenia, Azerbaijan, Georgia, Kazakhstan, Moldova, Russia, Ukraine and Belarus paired with the PAL/SECAM colour.
CCIR System C is an analog broadcast television system used between 1953 and 1978 in Belgium, Italy, Netherlands and Luxembourg as a compromise between Systems B and L. Used on VHF only.