View source for CCIR System B

{{Short description|625-line analog television transmission format}}

[[File:Analog-TV-Systems.jpg|thumb|500px|right|Analog TV systems global map, with System B in blue.]]

'''[[ITU-R#CCIR|CCIR]] System B''' (originally known as the "Gerber Standard"<ref>{{cite web |url=https://www.vintage-radio.net/forum/showthread.php?t=36027 |title=625-Line Television Broadcast Standards - UK Vintage Radio Repair and Restoration Discussion Forum}}</ref><ref>{{cite web |url=https://www.bvws.org.uk/405alive/faq/405_hist.html |title=405 Alive - FAQ - 405-Line Television in History |website=www.bvws.org.uk}}</ref><ref name=":0">{{cite web |url=https://ebha.org/ebha2007/pdf/Gaillard.pdf |title=The CCIR, the standards and the TV sets' market in France (1948-1985)}}</ref><ref>{{cite book |url=https://books.google.com/books?id=PdruCAAAQBAJ&dq=Gerber+Standard+625lines&pg=PA500 |title=Magnetic Recording Handbook |date=December 6, 2012 |publisher=Springer Science & Business Media |isbn=9789401094689 |via=Google Books}}</ref>) was the [[625 lines|625-line]] VHF analog [[Broadcast television systems|broadcast television system]] which at its peak was adopted by more than one hundred countries, either with [[PAL]] or [[SECAM]] colour.<ref>{{cite web |date=2005 |title=Weltweite Fernsehsysteme (NTSC, PAL und SECAM) |url=http://www.paradiso-design.net/weltweite_fernsehsysteme.html |archive-url=https://archive.today/20121209040135/http://www.paradiso-design.net/weltweite_fernsehsysteme.html |url-status=dead |archive-date=December 9, 2012 |access-date=2023-03-06 |website=www.paradiso-design.net}}</ref> It is usually associated with [[CCIR System G]] for UHF broadcasts.

'''System''' '''B''' was the first internationally accepted [[625-line]] broadcasting standard in the world. A first 625-line system with a 8&nbsp;MHz channel bandwidth was proposed at the CCIR Conference in Stockholm in July 1948 (based on 1946-48 studies in the Soviet Union<ref name="auto">{{cite web |title=Piet's Home-built Television |url=https://www.maximus-randd.com/piets-home-built-television-pt2.html |website=Maximus R&D}}</ref> by [[Mark Krivosheev]]<ref>{{cite web |title="M.I. Krivosheev: Participation in the development of mass TV broadcasting" - an exhibition at Ostankino TV Center |url=https://eng.rscc.ru/press/mi-krivosheev-participation-development-mass-tv-br/}}</ref><ref>{{cite web |title=Mark Iosifovich Krivosheev (1922-2018) |url=https://www.itu.int/en/Pages/Krivocheev.aspx}}</ref><ref name="60TH_ANNIVERSARY_OF_625">[http://625.625-net.ru/files/587/511/h_665921be9883776271895912fb8bb262 On the beginning of broadcast in 625-lines 60 year s ago, ''625'' magazine (in Russian).] {{webarchive |url=https://web.archive.org/web/20160304131236/http://625.625-net.ru/files/587/511/h_665921be9883776271895912fb8bb262|date=2016-03-04}}</ref><ref>[https://web.archive.org/web/20041230091501/http://www.ebu.ch/en/technical/trev/trev_255-portrait.pdf M.I. Krivocheev – an engineer's engineer, EBU's technical review.]</ref><ref>[https://web.archive.org/web/20070221210300/http://cra.ir/FTD/Static/RRC/RRCFile10.pdf In the vanguard of television broadcasting]</ref><ref>{{cite web |last=Observer |first=Reflective |date=2021-12-23 |title=Where did 625-line TV come from? |url=https://reflectiveobserver.medium.com/from-russia-with-television-a3d02007e22a |access-date=2021-12-31 |website=Medium |language=en}}</ref><ref>{{cite web |title=625-Line Television System Origins - UK Vintage Radio Repair and Restoration Discussion Forum |url=https://www.vintage-radio.net/forum/showthread.php?t=83653 |access-date=2021-12-31 |website=www.vintage-radio.net}}</ref>).<ref name=":0" /> At a  CCIR Geneva meeting in July 1950 Dr. Gerber (a Swiss engineer), proposed a modified 625-lines system with a 7&nbsp;MHz channel bandwidth (based on work by Telefunken and [[Walter Bruch]]), with the support of Belgium, Denmark, Italy, Netherlands, Sweden, Switzerland.<ref name="auto" /> 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.<ref name="auto" /><ref>{{cite web |title=World map showing the different line standards for black and white television after the CCIR Plenary Conference in Stockholm in 1952. Source: Rindfleisch, Hans, 'Der gegenwärtige Ausbau des Fernsehrundfunks im In-und Ausland', Rundfunktechnische Mitteilungen, 3, 1959, p.220. |url=https://www.researchgate.net/figure/World-map-showing-the-different-line-standards-for-black-and-white-television-after-the_fig6_346722680}}</ref>

In the 1960s, the capital of [[Mexico]], [[Mexico City]] decided to replace System B with 525-line [[CCIR System M]], despite the recommendations of [[Guillermo González Camarena|Guillermo González]] regarding the technical advantages of System B.

It is mostly replaced across Western Europe, former Yugoslavia, parts of Asia and Africa by [[DVB-T|digital broadcasting]].

== Specifications ==
The system was developed for [[Very high frequency|VHF]] (also known as VHF-3) band (part of RF band lower than 300&nbsp;MHz.) Some of the most important specs are listed below.<ref>Reference Data for Radio Engineers, ITT Howard W.Sams Co., New York, 1977, section 30</ref>

[[File:Channel spacing for CCIR television System B (VHF Bands).jpg|frame|Channel spacing for CCIR television System B (VHF Bands)<br>The separation between the aural and visual carriers is 5.5 MHz.]]

* [[Frame rate]]: 25&nbsp;Hz
* [[Interlaced video|Interlace]]: 2/1
* [[Refresh rate|Field rate]]: 50&nbsp;Hz<ref>Not an independent value: 25&nbsp;Hz•2=50&nbsp;Hz</ref>
* [[Film frame#Video frames|Lines/frame]]: 625
* [[Scan line|Line rate]]: 15.625&nbsp;kHz<ref>Not an independent value: 25&nbsp;Hz•625=15.625&nbsp;kHz</ref>
* [[Bandwidth (signal processing)|Visual bandwidth]]: 5&nbsp;MHz
* [[Modulation|Vision modulation]]: AC3 negative
* Preemphasis: 50 μs
* Sound modulation: F3
* Sound offset: 5.5&nbsp;MHz
* [[Broadcasting|Channel bandwidth]]: 7&nbsp;MHz

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&nbsp;Hz.

The '''video bandwidth''' is 5.0&nbsp;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|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 [[Emphasis (telecommunications)|preemphasis]] '''time constant''' of <math>\tau</math> = 50 μs. The '''deviation''' for a 1.0&nbsp;kHz. AF signal is 50&nbsp;kHz.

The separation between the primary audio FM subcarrier and the video carrier is 5.5&nbsp;MHz.

The total '''RF bandwidth''' of System B (as originally designed with its single FM audio subcarrier) was 6.5&nbsp;MHz, allowing System B to be transmitted in the 7.0&nbsp;MHz wide channels specified for television in the VHF bands with an ample 500&nbsp;kHz guard zone between channels.<ref>Nedim Ardoğa:TV Verici tekniğine giriş p.34</ref>

In specs, sometimes, other parameters such as vestigial sideband characteristics and [[gamma correction]] of the display device are also given.

=== Colour TV ===
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&nbsp;MHz and the sidebands of the PAL signal have to be truncated on the high-frequency side at +570&nbsp;kHz (matching the rolloff of the luminance signal at +5.0&nbsp;MHz). On the low-frequency side, the full 1.3&nbsp;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&nbsp;MHz deviating from +350±18&nbsp;kHz to -506±25&nbsp;kHz. The 'B' lines' carrier is at 4.250&nbsp;MHz deviating +506±25&nbsp;kHz to -350±18&nbsp;kHz.

Neither colour encoding system has any effect on the bandwidth of system '''B''' as a whole.

=== Improved audio ===
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&nbsp;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&nbsp;kHz. The alternative NICAM system uses an extra 500&nbsp;kHz, and needs to be spaced further from the primary audio subcarrier, thus System B with NICAM has only 150&nbsp;kHz guard zones between channels.

== Transmission channels ==
[[File:VHF Usage.svg|thumb|400px|right|Plan showing VHF frequency ranges for ITU Systems]]{{Unreferenced section|date=October 2024}}
The European 41-68&nbsp;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&nbsp;-&nbsp;E4) was agreed in 1952 at the ITU conference in Stockholm. The extension to VHF [[Band III]] (i.e. Channels E5&nbsp;-&nbsp;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.

=== Western Europe; Greenland; and most countries in Asia, Africa, and Oceania ===
{| class="wikitable"
! 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
|}

<p>† Channel 1 was allocated, but never used.</p><p>§ Not used in the former East Germany</p>

{| class="wikitable"
! 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
|}

==== East Germany before the 1960s ====
{| class="wikitable"
! {{No2}}Channel
! {{No2}}Channel limits (MHz)
! {{No2}}Vision carrier frequency (MHz)
! {{No2}}Main audio carrier frequency (MHz)
|-
| 1
| 58.00 - 65.00
| 59.25
| 64.75
|}

{| class="wikitable"
! {{No2}}Channel
! {{No2}}Channel limits (MHz)
! {{No2}}Vision carrier frequency (MHz)
! {{No2}}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.

=== Italy ===
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.

{| class="wikitable"
! {{No2}}Channel
! {{No2}}Channel limits (MHz)
! {{No2}}Vision carrier frequency (MHz)
! {{No2}}Audio carrier frequency (MHz)
|-
| IA
| 52.50 - 59.50
| 53.75
| 59.25
|-
| IB
| 61.00 - 68.00
| 62.25
| 67.75
|-
| IC{{Efn|group="Italy1"|Same as E4A}}
| 81.00 - 88.00
| 82.25
| 87.75
|}

{{notelist|group="Italy1"}}

Note: Band I is no longer used for television in Italy.

{| class="wikitable"
! {{No2}}Channel
! {{No2}}Channel limits (MHz)
! {{No2}}Vision carrier frequency (MHz)
! {{No2}}Audio carrier frequency (MHz)
|-
| ID{{Efn|group="Italy2"|Same as E5}}
| 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{{Efn|group="Italy2"|Same as E10}}
| 209.00 - 216.00
| 210.25
| 215.75
|-
| IH1{{Efn|group="Italy2"|Same as E11}}
| 216.00 - 223.00
| 217.25
| 222.75
|-
| IH2{{Efn|group="Italy2"|Same as E12}}
| 223.00 - 230.00
| 224.25
| 229.75
|}

{{notelist|group="Italy2"}}

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&nbsp;MHz from 177.5&nbsp;MHz (and identical to Germany's Band III DVB-T bandplan).

=== Australia VHF (until 1993) ===
Australia (along with Japan, System J and Eastern Europe, System D) were unique in the world by their use of [[Band II]] for television broadcasting.

{| class="wikitable"
! {{No2}}Channel
! {{No2}}Channel limits (MHz)
! {{No2}}Vision carrier frequency (MHz)
! {{No2}}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
|}

{| class="wikitable"
! {{No2}}Channel
! {{No2}}Channel limits (MHz)
! {{No2}}Vision carrier frequency (MHz)
! {{No2}}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
|}

{| class="wikitable"
! {{No2}}Channel
! {{No2}}Channel limits (MHz)
! {{No2}}Vision carrier frequency (MHz)
! {{No2}}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
|}

=== Australia VHF (after 1993) ===
{| class="wikitable"
! 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
|}

{| class="wikitable"
! 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.

{| class="wikitable"
! 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
|}

<p>♦ New channel allocations from 1993.</p><p>‡ Channels 10 and 11 were shifted up in frequency by 1&nbsp;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.</p>

=== Australia UHF ===
Australia is nearly unique in the world for their use of 7&nbsp;MHz channel-spacing (and therefore System B) on UHF.

{| class="wikitable"
! 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
|}

=== New Zealand and Indonesia ===
{| class="wikitable"
! 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
|}

{| class="wikitable"
|-
! 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
|}

<p>† Channels 10 and 11 weren't added until the late 1980s.</p><p>Note: The Band III frequencies are the same as Australia. Channel G1A is only used in Indonesia.</p>

=== Morocco ===
{| class="wikitable"
! 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
|}

== System G and H ==
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&nbsp;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&nbsp;MHz wider than for System B. That system for the UHF bands is known as [[CCIR System G|'''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&nbsp;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 [[CCIR System H|'''System H''']]. System '''H''' is similar to system '''G''' but the lower (vestigial) side band is 500&nbsp;kHz wider. This makes much better use of the 8.0&nbsp;MHz channels of the UHF bands (though whether any system B/H televisions actually made use of the extra bandwidth is not known).

== See also ==
* [[Broadcast television systems]]
* [[Television transmitter]]
* [[Transposer]]
* [[CCIR System G]]

== Notes and references ==
<references/>

== External links ==
* [https://web.archive.org/web/20120830232230/http://www.pembers.freeserve.co.uk/World-TV-Standards/Transmission-Systems.html World Analogue Television Standards and Waveforms]
* [https://archive.today/20121209040135/http://www.paradiso-design.net/weltweite_fernsehsysteme.html Fernsehnormen aller Staaten und Gebiete der Welt]
* [http://www.stjarnhimlen.se/tv/tv.html Analog TV Broadcast Systems]

{{Video formats}}
{{Analogue TV transmitter topics}}

[[Category:ITU-R recommendations]]
[[Category:Television technology]]
[[Category:Video formats]]
[[Category:Broadcast engineering]]
[[Category:CCIR System]]