18WuD2x

750 wideband • width mode
wideband 1. Having a bandwidth greater than the
minimum necessary to transmit a signal with acceptable
intelligibility. 2. For a voice signal, having
a bandwidth greater than 6 kHz. 3. Having
the capability to operate, without adjustment,
over a broad and continuous range of frequencies
or wavelengths. 4. In a digital network, a channel
having a bandwidth of more than 64 kbps but
less than 2 Mbps.
wideband amplifier An amplifier that exhibits reasonably
flat response to a broad band of frequencies.
The term is relative, depending on the
application.
wideband antenna An antenna that transmits or
receives signals over a broad frequency range,
usually without the need for tuning.
wideband axis In a color-television signal, the direction
of the fine chrominance primary phasor.
wideband communications 1. Communications
carried out over a band of frequencies wider than
the minimum necessary for effective transfer of
the information. 2. A method of transmitting and
receiving signals by deliberately varying the
channel frequency over a wide range. Also called
spread-spectrum communications.
wideband generator A signal generator covering a
wide frequency range. Typical coverage in a laboratory-type
instrument is 10 kHz to 1000 MHz.
wideband oscilloscope An oscilloscope whose horizontal,
vertical, and sweep channels operate over
a wide band of frequencies. Although the term
wideband is relative, a wideband oscilloscope is
usually assumed to be capable of displaying both
radio and audio frequencies.
wideband ratio The ratio B1/B2, where B1 is frequency
bandwidth and B2 is intelligence bandwidth.
wideband receiver A radio receiver that can tune
in signals over a broad range of frequencies. An
example is a communications receiver that can
cover 10 kHz to 30 MHz continuously.
wideband repeater A repeater capable of operating
over a wide range of input and output frequencies.
Such repeaters are used in active communications
satellites handling many different
channels at the same time.
wideband signal generator See WIDEBAND GEN-
ERATOR.
wideband sweep 1. In the operation of an oscilloscope,
a repetitive sweep of the electron beam,
the frequency of which is adjustable to any desired
point within a wide range. The basic sweep
rate in simple oscilloscopes is restricted to the
audio-frequency spectrum (up to about 20 kHz),
but a wideband sweep extends to much higher
frequencies, typically several tens of MHz. 2. A
sweep circuit that produces the wideband sweep
action described in 1.
wideband test meter An alternating-current (ac)
meter that can measure quantities over a wide
frequency range in its basic form (i.e., without
special external probes or converters). An example
is an electronic ac voltmeter with a range extending
from 10 Hz to 2.5 MHz.
wide-base diode A junction diode in which the p
region is considerably wider than the n region.
wide-open 1. Pertaining to wideband, untuned response.
2. Pertaining to maximum-gain operation
(e.g., a wide-open amplifier or receiver).
wide-range ammeter An ammeter that employs
one or more shunt resistances to increase the
full-scale deflection, usually by a power of 10 (10,
100, 1000, etc.). The resistor must be capable of
carrying the current without burning out.
Shunts are used when it is necessary to measure
very large currents, such as hundreds of amperes.
Shunts also allow a microammeter or milliammeter
to be used as a multimeter with many
current ranges.
wide-range reproduction High-fidelity audiofrequency
reproduction.
width 1. The horizontal dimension of a pulse, usually
corresponding to its effective duration; also
called PULSE DURATION. 2. The horizontal dimension
of an image, such as a television picture.
Voltage
+8
+6
+4
+2
0
Width
width, 1.
Time
width coding The modification of pulse duration
according to a code.
width coil See WIDTH CONTROL, 1.
width control 1. In a television receiver, the variable
component for adjusting the swing of the
horizontal deflection voltage and, therefore, the
width of the picture. It is often a slug-tuned coil
connected in parallel with a portion of the secondary
winding of the horizontal output transformer.
2. Sometimes, the horizontal gain control
in an oscilloscope.
width mode In electronic-counter operations, a
time-interval mode in which the signal is
measured.