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Glossary

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lowest frequencies carried by a channel. Also the speed (bit-rate velocity at

which data can be transferred and presented.

C/N; also CNR Carrier-to-Noise ratio, normally expressed in dB: the ratio of

peak carrier power to root mean square (RMS) noise power (noise floor at

video bandwidth) adjacent to the carrier.

½ See Noise Offset.

CATV Community Antenna Television, commonly used to refer to Cable

Television.

Channel In the US a 6 MHz-wide band of frequencies allocated for use in

television broadcasting, designated by number. For example, Channel 7

occupies the band from 174 to 180 MHz.

In Europe the standard is 8 MHz

Channel Plan Analysis and enumeration/identification of television channels

present on a CATV system.

CPD Common Path Distortion: a form of inter-modulation distortion caused

by mixing when an RF spectrum passes through a non-linear junction. Also

caused by material deterioration and irregularities in the transmission line.

CSO Composite Second Order: clustering of second-order beats at any

frequency of the spectrum. CSO in the video bandwidth can cause distortion

of video in cable systems. Measured as the ratio, in dB, of the peak level of

the visual carrier to the peak of the average level of CSO.

CTB Composite Triple Beat: spurious frequencies generated by the sum and

difference products of any three carriers passing through s non-linear circuit

or device. Detected as a voltage.

CW Continuous Wave. Under steady-state conditions, successive CW

oscillations are identical.

D/U Desired/Undesired, also called Carrier to Garbage

DVA Ratio of video level to audio level, expressed in dB.

Depth of Modulation Ratio of peak downward change in modulation to

carrier amplitude, expressed as a percentage. (Roddy/Coolen)

DSP Digital Signal Processor: converts digital input into analogue or pulse-

rate outputs.

DTV Digital TV

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