1-2
AIR-CORE TRANSFORMER—A transformer composed of two or more coils that are wound around a
nonmetallic core [2].
ALLOWANCE PARTS LIST (APL)—Repair parts required for units having the equipment/ component
listed [14].
ALLOYED JUNCTION—A junction formed by recrystallization of a molten region of P-type material on
an N-type substrate, or vice versa [7].
ALPHA—The emitter-to-collector current gain in a common-base circuit [7].
ALTERNATING CURRENT—An electrical current that constantly changes amplitude and changes
polarity at regular intervals [2].
ALTITUDE—The vertical distance of an aircraft or object above a given reference, such as ground or sea
level [18].
ALUMINUM CREEP—(1) The movement of aluminum wire from a point where pressure is applied. (2)
The "retreat" of heated aluminum wire as it cools [4].
AMBIENT TEMPERATURE—The surrounding temperature such as the temperature of air surrounding a
conductor in a compartment or within a piece of equipment [4].
AMBIGUOUS RETURNS—Echoes that exceed the prt of a radar and appear at incorrect ranges [18].
AMERICAN WIRE GAUGE (AWG)—The standards adopted in the United States for the measurement of
wire sizes [4].
AMMETER—An instrument for measuring the amount of electron flow (in amperes) [1] [3] [6].
AMPERE—The basic unit of electrical current [1].
AMPERE-TURN—The magnetomotive force developed by 1 ampere of current flowing through a coil of
one turn [8].
AMPERITE (BALLAST) TUBE—A current-controlling resistance device designed to maintain
substantially constant current over a specified range of variation in applied voltage or resistance of a
series circuit [6].
AMPLIDYNE—A special dc generator in which a small dc voltage applied to field windings controls a
large output voltage from the generator. In effect, an amplidyne is a rotary amplifier that often times
produces gain of approximately 10,000 [5].
AMPLIFICATION—(1) The process of enlarging a signal in amplitude (as of voltage or current) [8]. (2)
The ratio of output magnitude to input magnitude in a device that is intended to produce an output that
is an enlarged reproduction of its input [6] [7].
AMPLIFICATION FACTOR—The voltage gain of an amplifier with no load on the output [6] [7].
AMPLIFIER—The device that provides amplification (the increase in current, voltage, or power of a
signal) without appreciably altering the original signal [7] [8].
AMPLITRON—See CROSS-FIELD AMPLIFIER [18].
