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Chapter 7 Help & Assistance
Chapter 7 Help & Assistance
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Glossary of Technical Terms
4:3 (also written 4 x 3): This is just an easier way of writing the aspect ratio so it appears in whole numbers instead
of saying 1 x 1.33 (4 divided by 3 = 1.33).
To continue, 4 x 3 is the aspect ratio (width to the height) of standard definition televisions and NTSC pictures.
4:3 is the ratio of the width of the picture screen to the height — a 4:3 television with a width of 20 inches will
have height of 15 inches.
16:9 (also written 16 x 9): This is just an easier way of writing the aspect ratio of High Definition Televisions so it
appears in whole numbers instead of writing 1 x 1.77 (16 divided by 9 = 1.77) — the aspect ratio for HDTV. The
aspect ratio is the ratio of the width to the height — a 16:9 television with a width of 48 inches will have a height
of 27 inches.
AC-3 (also called Dolby Digital): Digital surround sound technology that delivers five full channels of audio, with a
sixth subwoofer channel (that’s the .1). HDTV signals include Dolby Digital 5.1 audio information.
Access card: The card provided by DIRECTV that enables you to subscribe to DIRECTV programming. This card
has already been inserted into the slot that’s on the back of your television.
Amplifier: A component used to increase the voltage of any power signal fed to it.
Analog (also called terrestrial): A type of signal that is broadcast over the airwaves. Technically, a signal that has
many varying levels instead of being discrete or digital.
Aspect ratio: Ratio of the width of a picture screen to its height. See 4:3 and 16:9.
ATSC (Advanced Television Standards Committee): Industry group formed to define digital television (DTV)
standards, such as HDTV and SDTV. See also ATSC Formats.
ATSC formats: A series of 18 digital television formats, approved by the FCC (Federal Communications
Commission) for use by the television broadcast industry.
The 18 DTV formats defined by the ATSC include both HDTV and SDTV formats to be used by off-air
broadcasters. Other formats have been defined by manufacturers and by satellite and cable broadcasters.
Thomson digital television products are designed to accept and display a picture of appropriate quality from any
of the 18 FCC-approved formats, and from all digital formats defined by DIRECTV.
A/V cable (audio/video cable): These cables are sometimes called RCA cables. Usually, they are color-coded (yellow
is video, white is left/mono audio, and red is right audio). See composite video.