18WuD2x

128 color spectrum • coma lobes
To
ultraviolet,
Xrays,
Gamma rays
Violet
Indigo
Blue
Green
Yellow
Orange
Red
0.4
0.5
0.6
0.7
To
infared,
radio waves
Wavelength, µm
as violet, blue, green, yellow, orange, and red, in
order of increasing intensity.
Colpitts oscillator A radio-frequency (RF) oscillator
that uses a single, untapped inductor. A combination
of two fixed capacitors in series is
connected in parallel with the inductor. The feedback
is controlled by the ratio of capacitances. A
permeability-tuned coil or a roller inductor can be
used to obtain variable-frequency operation. Stability
is enhanced when the output of the oscillator
is taken from the emitter or source portion of
the circuit. To prevent the output signal from being
short-circuited to ground, an RF choke is connected
in series with the emitter or source.
Compare HARTLEY OSCILLATOR.
color spectrum
Angstroms), orange, yellow, green, blue, indigo,
and violet at 410 to 390 nm (4100 to 3900
Angstroms).
color subcarrier A modulated monochrome signal
whose sidebands convey color information.
color-sync signal See COLOR BURST.
color system Also called RGB color model. A means
of representing a color in terms of mathematical
coordinates. This can be done in three dimensions
because there are three COLOR PRI-
MARIES. Each color primary is represented by an
axis. Any COMPOSITE COLOR can be represented
by a unique vector. The relative amount of
each color primary is given by the length of the
composite-color vector components along each
axis.
color television Television in which the picture
approximates natural color. It operates on the basis
of mixing three primary colors (red, blue, and
green) of phosphors on the picture tube screen.
color television receiver A television receiver designed
to reproduce color pictures.
color television signal The signal transmitted by
a color television transmitter, containing all of the
information needed to reproduce a complete, fullcolor,
moving image.
color transmission The television transmission of
a picture in color.
color triad On the screen of a color picture tube,
one of the color cells, each of which contains one
of the three phosphor dots: red, green, and blue.
color triangle A triangle that can be inscribed on a
chromaticity diagram to reveal the chromaticity
range resulting from adding the three color primaries.
color TV signal The complete signal (video, color,
and sync components) required for transmitting a
picture in color.
color weather radar A computer-enhanced radar
rendition of weather patterns, usually showing
various intensities of precipitation as different
colors. Commonly, areas of precipitation show up
Colpitts oscillator
columbium Symbol, Cb. The former name of the
metallic element niobium. Atomic number, 41.
Atomic weight, 92.9064.
column See CARD COLUMN.
columnar graph A graphical presentation of data,
in which the ordinates are represented by vertical
columns whose height depends on the value.
Commonly used in presentation graphics, but less
common in analytical graphics.
column binary Binary number representation on
punched cards, wherein consecutive digits correspond
to consecutive column punching positions.
column speaker An acoustic speaker with a long
cabinet, so that a large column of air is used for
resonating or reinforcing purposes. This type of
speaker radiates over a wide azimuth angle, while
providing a narrow beam in the elevation plane.
column split On a punched card machine, the device
for reading, as two separate characters or
codes, two parts of a single column.
COM 1. Abbreviation for communications port.
2. Abbreviation for computer output on microfilm.
coma An aberration that causes the beam spot on
the screen of a cathode-ray tube to resemble a
comet.
coma lobes An aberration in the radiation or response
pattern of a dish antenna that occurs
when the radiating element is not exactly at the
focal point of the reflector. When the directional