Extron electronic 6400s - Manual (Page 63)

A-7 Matrix 3200/6400 Series • Reference Information
Chroma – The characteristics of color information, independent of luminance
intensity. Hue and saturation are qualities of chroma. Black, gray, and white
objects do not have chroma characteristics.
Chrominance Signal – Part of a television signal containing the color
information. Abbreviated by “C”.
Coaxial Cable – A two-conductor wire in which one conductor completely wraps
the cable.
Component Video – Our color television system starts with three channels of
information; Red, Green, & Blue (RGB). In the process of translating these
channels to a single composite video signal they are often first converted to
Y, R-Y, and B-Y. Both 3-channel systems, RGB and Y, R -Y, B -Y are
component video signals. They are the components that eventually make up
the composite video signal. Much higher program production quality is
possible if the elements are assembled in the component domain.
Composite Sync – A signal consisting of horizontal sync pulses, vertical sync
pulses, and equalizing pulses only, with no signal reference level.
Composite Video – A mixed signal comprised of the luminance (black and
white), chrominance (color), blanking pulses, sync pulses and color burst.
Contrast – The range of light and dark values in a picture or the ratio between
the maximum and the minimum brightness values. Low contrast is shown
mainly as shades of gray, while high contrast is shown as blacks and whites
with very little gray. It is also a TV monitor adjustment which increases or
decreases the level of contrast of a televised picture.
Crosstalk – Interference from an adjacent channel which adds an undesirable
signal to the desired signal.
Crosstalk Isolation – Attenuation of an undesired signal introduced by crosstalk
from an adjacent channel.
CRT – Cathode Ray Tube – A vacuum tube that produces light when energized
by the electron beam generated inside the tube. A CRT has a heater
element, cathode, and grids in the neck of the tube, making up the “gun”. An
electron beam is produced by the gun and is accelerated toward the front
display, or screen surface of the tube. The display surface contains
phosphors that light up when hit by the electron beam. The CRT is more
commonly known as picture tube.
dB – Decibel – The standard unit used to express gain or loss of power. It
indicates the logarithmic ratio of output power divided by input power. A
power loss of 3 dB is an attenuation of half of the original value. The term
“3dB down” is used to describe the “half power point”.
DC – Direct Current – The flow of electrons in one direction.
D Connector – A connector with rounded corners and angled ends, taking on
the shape of the letter “D”. Commonly used in computers and video.
Decibel – See dB.
Decoder – A device used to separate the RGBS (Red, Green, Blue and Sync)
signals from a composite video signal.
Differential Audio – See Balanced Audio.
Distribution Amplifier (DA) – A device that allows connection of one input
source to multiple output sources such as monitors or projectors.
FCC – Federal Communications Commission – A unit of the U.S. Government
that monitors and regulates communications.
Field – In interlaced video, it takes two scans on a screen to make a complete
picture, or a “Frame”. Each scan is called a “Field”. Sometimes these are
referred to as “field 1 and field 2”.
Flicker – Flicker occurs when the electron gun paints the screen too slowly,
giving the phosphors on the screen time to fade.