18WuD2x

asic frequency • battery 65
basic frequency 1. The FUNDAMENTAL FRE-
QUENCY of a signal, as opposed to one of its harmonics.
2. See BASE FREQUENCY, 1.
basic protection Devices and procedures essential
to minimize the risk of damage to electronic
equipment, and/or injury or death to its operators,
as a result of lightning. Hardware provisions
include a substantial earth ground, heavy-gauge
grounding wire, lightning arrestors for antennas,
and transient suppressors for power connections.
The safest procedure is to disconnect and ground
all antennas, and unplug all equipment from utility
outlets, during electrical storms and/or when
the apparatus is not in use. Radio communications
equipment with outdoor antennas, in
particular, should not be operated during
thunderstorms.
basket The structure that supports the cone in an
acoustic loudspeaker.
basket-weave coil A type of single-layer inductor
in which adjacent turns do not parallel each
other around the circumference, but zigzag oppositely
as a strand does in the woven pattern of a
basket. This reduces distributed capacitance.
bass Low audio frequencies (AF) corresponding to
low-frequency musical notes or sounds.
bass boost 1. The special emphasis given to low
audio frequencies (the bass notes) by selective
circuits in audio systems. 2. The technique of increasing
the loudness of the bass, relative to the
higher audio frequencies, to render a more faithful
reproduction of sound at low volume levels.
bass compensation See BASS BOOST, 2.
bass control 1. A manually variable potentiometer
for adjusting bass boost of an amplifier or sound
system. 2. The arrangement of components that
are required to achieve amplitude variation of
bass in an audio signal.
bass port In a loudspeaker, a hole in the cabinet
that enhances the low-frequency (bass) sound
output. Used in high-fidelity audio systems.
bass-reflex enclosure A loudspeaker cabinet with
a critically dimensioned duct or port that allows
back waves to be radiated in phase with front
waves, thus averting unwanted acoustic phase
cancellation.
bass-reflex loudspeaker A loudspeaker mounted
in a bass reflex enclosure. Also see ACOUSTICAL
PHASE INVERTER.
bass-resonant frequency The low frequency at
which a loudspeaker or its enclosure displays
resonant vibration.
bass roll-off 1. The attenuation of the low-frequency
(bass) component in a high-fidelity audio
signal. 2. A control that allows adjustable attenuation
of the low-frequency component in a highfidelity
audio signal.
bass suppression In speech transmission, the removal
of all frequencies below about 300 Hz, on
the assumption that those frequencies contribute
little to intelligibility. This suppression permits
the speech level to be increased without overmodulating
a transmitter. It also allows smaller audio
transformers to be used because transformer
core size must increase as the frequency it passes
decreases.
bassy In audio and high-fidelity applications, a
sound in which the low-frequency components,
below about 500 Hz, are overly predominant.
BAT Abbreviation of BATTERY.
batch fabrication process The manufacture of devices
in a single batch from materials of uniform
grade. Particularly, the manufacture of a large
number of semiconductor devices from one batch
of semiconductor material by means of carefully
controlled, identical processes.
batch processing In digital-computer operations,
the processing of quantities of similar information
during a single run.
bat-handle switch A toggle switch, the lever of
which is relatively long and thick, and is shaped
like a baseball bat.
bat-handle switch
bathtub capacitor A (usually oil-filled) capacitor
housed in a metal can that looks like a miniature
bathtub.
bathyconductorgraph An instrument that is used
to measure the electrical conductivity of seawater.
bathythermograph An instrument that plots a
graph of temperature versus depth in a body of
water, such as a lake or an ocean.
batten Supporting bars or braces that hold a loudspeaker
in place within its cabinet, and/or that
hold the cabinet panels in place.
battery Abbreviations, B, BA. BAT. A device consisting
of two or more interconnected electrochemical
or photovoltaic cells that generate dc
electricity. The cells can be connected in series to
supply a desired voltage, in parallel to supply a
desired current-delivering capability, or in seriesparallel
to obtain a desired voltage and currentdelivering
capability. Also see CELL, EDISON
BATTERY, LEAD-ACID BATTERY, PHOTO-