18WuD2x

AFIPS • aircraft bonding 17
AFIPS Acronym for American Federation of Information
Processing Societies.
afpc Abbreviation of automatic frequency/phase
control.
AFSK Abbreviation of AUDIO-FREQUENCY-SHIFT
KEYING.
afterglow The tendency of the phosphor of a cathode-ray-tube
screen to glow for a certain time after
the cathode-ray beam has passed. Also see
PERSISTENCE.
afterpulse An extraneous pulse in a multiplier
phototube (photomultiplier), induced by a preceding
pulse.
AF transformer See AUDIO-FREQUENCY TRANS-
FORMER.
a/g Abbreviation of AIR-TO-GROUND.
AGC Abbreviation of AUTOMATIC GAIN CONTROL.
AGE Abbreviation of AEROSPACE GROUND
EQUIPMENT.
agent An active force, condition, mechanism, or
substance that produces or sustains an effect.
Thus, a sudden voltage rise is a triggering agent
in certain bistable circuits; arsenic is a doping
agent in semiconductor processing; the slow cooling
of a heated metal to improve ductility is an
ANNEALING AGENT.
aging 1. An initial run of a component or circuit
over a certain period of time shortly after manufacture
to stabilize its characteristics and performance.
2. The changing of electrical
characteristics or of chemical properties over a
protracted period of time.
agonic line An imaginary line connecting points on
the earth’s surface at which a magnetic needle
shows zero declination (i.e., points to true geographic
north).
AGREE Acronym for Advisory Group on Reliability
of Electronics Equipment.
Ah Abbreviation of AMPERE-HOUR. Depending on
the standard used, the abbreviation can be amphr,
a-h, a-hr, or A-h.
aH Abbreviation of ATTOHENRY.
aided tracking In radar and fire control, a system
in which manual correction of target tracking error
automatically corrects the rate of movement
of the tracking mechanism.
AIEE Abbreviation for American Institute of Electrical
Engineers, now consolidated with the IRE,
forming the IEEE.
AIP Abbreviation for American Institute of Physics.
air The mixture of gases that constitutes the
earth’s atmosphere and figures prominently in
the manufacture and operation of numerous
electronic devices. By volume, air contains about
21 percent oxygen, 78 percent nitrogen, and
lesser amounts of argon, carbon dioxide, helium,
hydrogen, krypton, neon, and xenon. It also contains
varying amounts of water vapor, and in
smoggy areas, carbon monoxide and the oxides of
sulfur and nitrogen.
airborne intercept radar A type of short-range
radar used aboard fighter and interceptor aircraft
for tracking their targets.
airborne long-range input Equipment aboard aircraft,
for the purpose of facilitating the use of
long-range missiles.
airborne noise See ACOUSTIC NOISE.
airborne radar platform Surveillance and altitude-finding
radar used aboard aircraft.
air capacitor A capacitor in which air is the dielectric
between two sets of conductive plates. Also
called air-dielectric capacitor.
aircarrier aircraft station On an aircraft, a radio
station that is involved in carrying people for hire
or in transporting cargo.
air cell A primary electrochemical cell in which the
positive electrode is depolarized by reduced oxygen
in the air.
air cleaner See DUST PRECIPITATOR.
air column The open space inside an acoustic
chamber, pipe, or horn.
air-cooled component A component, such as a
power transistor, that is cooled by circulating air,
compared with one cooled by a circulating liquid,
such as water or oil.
air-cooled transistor A transistor (particularly a
power transistor) from which the heat of operation
is drawn away, through radiation and convection,
into the surrounding air. The transistor
is usually mounted on a heatsink or fitted with
fins.
air-cooled tube An electron tube from which heat
is drawn away, mainly via convection, into the
surrounding air. A device called a chimney can be
placed around the tube, through which air is
blown by a fan. Cool air enters through the bottom
of the assembly, and hot air escapes from the
top.
air-core inductor A coil of wire wound around a
hollow cylindrical form or in a loop, designed to
introduce inductive reactance into a circuit or
system. In practice, the maximum attainable inductance
is approximately 1 mH. This type of inductor
is used in some wireless transmitters,
receivers, and antenna networks. The component
can be designed for high current-carrying capacity
by using heavy-gauge wire and a large winding
radius. The magnetic lines of flux extend considerably
beyond the interior of the coil, especially
along the winding axis. This increases the likelihood
of mutual inductance between the coil and
surrounding electrical components, devices, or
circuits.
air-core transformer A transformer without a ferromagnetic
core, so called because air is the only
material at the center of (and immediately surrounding)
the transformer coils.
aircraft bonding The practice of solidly connecting,
for electrical purposes, the metal parts of an
aircraft, including the engine.