Editing NTSC (section)

=== Transmission modulation method ===
[[File:Ntsc channel.svg|thumb|400px|Spectrum of a System M television channel with NTSC color]]

An NTSC [[television channel]] as transmitted occupies a total bandwidth of 6&nbsp;MHz. The actual video signal, which is [[amplitude modulation|amplitude-modulated]], is transmitted between 500&nbsp;[[Hertz|kHz]] and 5.45&nbsp;MHz above the lower bound of the channel. The video [[Carrier wave|carrier]] is 1.25&nbsp;MHz above the lower bound of the channel. Like most AM signals, the video carrier generates two [[sideband]]s, one above the carrier and one below. The sidebands are each 4.2&nbsp;MHz wide. The entire upper sideband is transmitted, but only 1.25&nbsp;MHz of the lower sideband, known as a [[Single-sideband modulation|vestigial sideband]], is transmitted. The color subcarrier, as noted above, is 3.579545&nbsp;MHz above the video carrier, and is [[quadrature amplitude modulation|quadrature-amplitude-modulated]] with a suppressed carrier. The audio signal is [[Frequency modulation|frequency modulated]], like the audio signals broadcast by [[FM broadcasting|FM radio]] [[Radio broadcasting|stations]] in the 88–108&nbsp;MHz band, but with a 25&nbsp;kHz maximum [[frequency deviation]], as opposed to 75&nbsp;kHz as is used on the [[FM broadcast band|FM band]], making analog television audio signals sound quieter than FM radio signals as received on a wideband receiver. The main audio carrier is 4.5&nbsp;MHz above the video carrier, making it 250&nbsp;kHz below the top of the channel. Sometimes a channel may contain an [[Multichannel Television Sound|MTS]] signal, which offers more than one audio signal by adding one or two subcarriers on the audio signal, each synchronized to a multiple of the line frequency. This is normally the case when [[Stereophonic sound|stereo audio]] and/or [[second audio program]] signals are used. The same extensions are used in [[ATSC standards|ATSC]], where the ATSC digital carrier is broadcast at 0.31&nbsp;MHz above the lower bound of the channel.

"Setup" is a 54&nbsp;mV (7.5&nbsp;[[IRE (unit)|IRE]]) voltage offset between the "black" and "blanking" levels. It is unique to NTSC. CVBS stands for Color, Video, Blanking, and Sync.

The following table shows the values for the basic RGB colors, encoded in NTSC<ref>{{cite web |title=Color Bar Levels, Amplitues, and Phases |url=https://www.edn.com/wp-content/uploads/media-1050361-c0195-table1.gif |access-date=February 22, 2022 |website=Edn.com |format=GIF}}</ref>

{| class="wikitable"
|+ Analog signal values for basic RGB colors, encoded in NTSC
! Color
! [[Luma (video)|Luminance]] level ([[IRE (unit)|IRE]])
! [[Chrominance]] level (IRE)
! Chrominance amplitude (IRE)
! Phase (º)
|-
! White
| 100.0
| 0.0
| 0.0
|–
|-
! Yellow
| 89.5
| 48.1 to 130.8
| 82.7
| 167.1
|-
! Cyan
| 72.3
| 13.9 to 130.8
| 116.9
| 283.5
|-
! Green
| 61.8
| 7.2 to 116.4
| 109.2
| 240.7
|-
! Magenta
| 45.7
| −8.9 to 100.3
| 109.2
| 60.7
|-
! Red
| 35.2
| −23.3 to 93.6
| 116.9
| 103.5
|-
! Blue
| 18.0
| −23.3 to 59.4
| 82.7
| 347.1
|-
! Black
| 7.5
| 0.0
| 0.0
|–
|}