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C

CABLE

Either a stranded conductor (single-conductor cable) or a combination of conductors insulated from one another (multiple conductor cable). Small sizes are commonly referred to as stranded wire or as cords [4].


CABLE HARNESS

A group of wires or ribbons of wiring used to interconnect electronic systems and subsystems [14].


CAPACITANCE

The property of an electrical circuit that opposes changes in voltage [2].

CAPACITIVE REACTANCE

The opposition, expressed in ohms, offered to the flow of an alternating
current by capacitance. The symbol for capacitive reactance is X C [2] [9].


CAPACITOR

An electrical device capable of storing electrical energy in an electrostatic field [2].

CAPACITOR FILTER

This filter is used on extremely high-voltage, low-current power supplies and
also where the ripple frequency is not critical [7].


CAPACITOR-START MOTOR

A type of single-phase, ac induction motor in which a starting winding
and a capacitor are placed in series to start the motor. The values of XC and R are such that the main-winding and starting-winding currents are nearly 90 degrees apart and the starting torque is produced as in a two-phase motor [5].


CARBON MICROPHONE

A microphone in which sound waves vary the resistance of a pile of carbon
granules. May be single-button or double-button [12].


CARDIOPULMONARY RESUSCITATION

Procedure designed to restore breathing after cardiac arrest. Includes clearing air passages to lungs and heart massage [1].


CARRIER FREQUENCY

The frequency of an unmodulated transmitter output [12] [18].

CARRIER-CONTROLLED APPROACH

A shipboard radar system used to guide aircraft to safe landings in poor visibility conditions [18].


CARRY

(1) One or more digits, produced in connection with an arithmetic operation, that is/are forwarded to another digit place for processing there. (2) The number represented by the digit or digits in (1) above [13].


CATCHER GRID

In a velocity-modulated tube, a grid on which the spaced electron groups induce a signal. The output of the tube is taken from the catcher grid [11].


CATHODE

(1) In an electron tube the electrode that is the source of current flow [6]. (2) The general name for any negative electrode [1]. (3) The negative terminal of a forward-biased semiconductor diode, which is the source of the electrons [7].


CATHODE BIAS

The method of biasing a vacuum tube in which the biasing resistor is placed in the common-cathode return circuit, thereby making the cathode more positive with respect to ground [6].


CATHODE KEYING

A system in which the cathode circuit is interrupted so that neither grid current nor plate current can flow [12].


CATHODE MODULATOR

Voltage on the cathode is varied to produce the modulation envelope [12].

CATHODE SPUTTERING

A process of producing thin film components [14].

CATHODE-RAY TUBE (CRT)

An electron tube that has an electron gun, a deflection system, and a
screen. This tube is used to display visual electronic signals [6].


CAVITY RESONATOR

A space totally enclosed by a metallic conductor and supplied with energy in
such a way that it becomes a source of electromagnetic oscillations. The size and shape of the enclosure determine the resonant frequency [11].


CAVITY WAVEMETER

An instrument used to measure microwave frequencies [16].

CELL

A single unit that transforms chemical energy into electrical energy. Batteries are made up of cells [1].


CENTER-FEED METHOD

Connecting the center of an antenna to a transmission line which is then
connected to the final (output) stage of the transmitter [10].


CENTIMETER CUBE

A unit of volume of large rectangular or square conductors. The cross-sectional
area equals 1 square centimeter with a length of 1 centimeter [4].


CHANNEL

A carrier frequency assignment, usually with a fixed bandwidth [12].

CHARACTER

A letter, digit, or other symbol that is used as part of the organization, control, or representation of information [13].


CHARACTERISTIC IMPEDANCE

The ratio of voltage to current at any given point on a transmission line represented by a value of impedance [10].


CHARGE

Represents electrical energy. A material having an excess of electrons is said to have a negative charge. A material having a shortage of electrons is said to have a positive charge [1].


CHARGE CYCLE

The period of time that a capacitor in an electrical circuit is storing a charge [2].

CHOKE

An inductor used to impede the flow of pulsating dc or ac by means of self-inductance [6] [7].

CHOKE JOINT

A joint between two sections of waveguide that provides a good electrical connection without power losses or reflections [11].


CIRCUIT

The complete path of an electric current [1].

CIRCULAR MIL

An area equal to that of a circle with a diameter of 0.001 inch. It is used for measuring the cross-sectional area of wires [1].


CIRCULAR MIL-FOOT

A unit of volume of a conductor having a cross-sectional area of 1 circular mil
and a length of 1 foot [4].


CLAMPER

A circuit in which either the upper or lower extremity of a waveform is fixed at a desired value [9].


CLASS A AMPLIFIER OPERATION

The type of operation in which the amplifier is biased so that variations in input signal polarities occur within the limits of cutoff and saturation [7].


CLASS AB AMPLIFIER OPERATION

The type of operation in which the amplifier is biased so that collector current is cut off for a portion of the alternation of the input signal [7].


CLASS B AMPLIFIER OPERATION

The type of operation in which the amplifier is biased so that collector current is cut off for one-half of the input signal [7].


CLASS C AMPLIFIER OPERATION

The type of operation in which the amplifier is biased so that collector current is cut off for more than one-half of the input signal [7] [13].


CLUTTER

Confusing, unwanted echoes that interfere with the observation of desired signals on a radar indicator [18].


COAXIAL CABLE

Cable in which the center conductor is separated from an outer conductor by a
dielectric material; used in RF transmission [4].


COAXIAL LINE

A type of transmission line that contains two concentric conductors [10].

CODE

In teletypewriter operation, code is a combination of mark and space conditions representing symbols, figures, or letters [17].


COEFFICIENT OF COUPLING

An expression of the extent to which two inductors are coupled by
magnetic lines of force. This is expressed as a decimal or percentage of maximum possible coupling and represented by the letter K [2].


COHERENCE

A definite phase relationship between two energy waves, such as transmitted frequency and reference frequency [18].


COHERENT

Radiation on one frequency [17].

COHERENT OSCILLATOR

In cw radar an oscillator that supplies phase references to provide coherent
video from target returns [18].


COIL

An inductive device made by looping turns of wire around a core [2].

COLD-CATHODE TUBE

A gas-filled electron tube that conducts without the use of filaments. Cold-
cathode tubes are used as voltage regulators [6].


COLLECTOR

The element in a transistor that collects the current carriers [7].

COLLECTOR-INJECTION MODULATOR

The transistor equivalent of a plate modulator. Modulating voltage is applied to a collector circuit [12].


COLLINEAR ARRAY

An array with all the elements in a straight line. Maximum radiation is
perpendicular to the axis of the elements [10].


COMBINATION ARRAY

An array system that uses the characteristics of more than one array [10].

COMBINATION CIRCUIT

A series-parallel circuit [1].

COMBINATION PEAKING

A technique in which a combination of peaking coils in series and parallel
(shunt) with the output signal path is used to improve high-frequency response [8].


COMMON BASE

A transistor circuit in which the base electrode is the common element to both input and output circuits [7].


COMMON COLLECTOR

A transistor circuit configuration in which the collector is the element
common to both the input and the output circuits [7].


COMMON EMITTER

A circuit configuration in which the emitter is the element common to both the
input and the output circuits [7].


COMMON IDENTITIES LAW

In Boolean algebra this law states that anytime the expression A(A + B)= AB or A + AB = A + B appears, it can immediately be simplified to AB without going through the process of using the distributive law, complementary law, or the law of union to simplify [13].


COMMON-BASE DETECTOR

An amplifying detector in which detection occurs in the emitter-base
junction and amplification occurs at the output of the collector junction [12].


COMMON-EMITTER DETECTOR

Often used in receivers to supply detected and amplified output. The emitter-base junction acts as the detector [12].


COMMUTATION

The act of a commutator in converting generator output from an ac voltage to a dc voltage [5].


COMMUTATIVE LAW

In Boolean algebra this law states that changing the order of the terms in an
equation will not affect the value of the equation. Example: A + B = B + A; A • B = B • A [13].


COMMUTATOR

A mechanical device that reverses armature connections in motors and generators at the proper instant so that current continues to flow in only one direction. In effect, the commutator changes ac to dc [5].


COMPARATOR

An equipment that compares incoming signals and selects the strongest to be fed to a teletypewriter through a patch panel. This is used in diversity operation [17].


COMPENSATING WINDINGS

Windings embedded in slots in pole pieces, connected in series with the
armature, whose magnetic field opposes the armature field and cancels armature reaction [5].


COMPENSATION

The process of overcoming the problems associated with high frequencies in an
amplifier [8].


COMPLEMENT

A number or state that is the opposite of a specified number or state. The negative of a number is often represented by its complement [13].


COMPLEMENT NUMBER

A number that when added to another number gives a sum equal to the base
of the number system of operation. For example, in the decimal number system, the complement of 1 is 9 [13].


COMPLEMENTARY (SECONDARY) COLORS OF LIGHT

The colors of light produced when two of the primaries are mixed in verlapping beams of light. The complementary colors of light are magenta, yellow, and cyan [10].


COMPLEMENTARY LAW

In Boolean algebra this law states that the logical addition of a quantity and
its complement will result in 1 and the logical multiplication of a quantity and its complement will result in a product of 0 [13].


COMPLEX WAVE

(1) A waveform other than a sine wave [9]. (2) A wave that is produced by
combining two or more pure tones at the same time [10] [12].


COMPOUND-WOUND MOTORS AND GENERATORS

Machines that have a series field in addition to a shunt field. Such machines have characteristics of both series- and shunt-wound machines [5].


COMPRESSION WAVES

Longitudinal waves that have been compressed (made more dense) as they
move away from the source [10].


COMPUTER

A data processor that can perform substantial computation, including numerous arithmetic or logic operations, without intervention by a human operator during the run [13].


CONCURRENT

Pertaining to the occurrence of two or more events or activities within the same specified interval of time [13].


CONDUCTANCE

The ability of a material to conduct or carry an electric current. It is the reciprocal of the resistance of the material and is expressed in mhos or siemens [1] [4] [10].


CONDUCTION BAND

A partially filled energy band in which electrons can move freely [7].

CONDUCTIVITY

The ease with which a substance transmits electricity [1].

CONDUCTOR

(1) A material with a large number of free electrons. (2) A material that easily permits electric current to flow [1].


CONDUIT

A tubular raceway, usually metal or plastic, for holding wires or cables [4].

CONICAL SCANNING

Scanning in which the movement of the beam describes a cone, the axis of
which coincides with that of the reflector [18].


CONNECTED ARRAY

Another term for DRIVEN ARRAY [10].

CONTACT

In radar, an object that reflects RF energy; target [18].

CONTINUITY

An uninterrupted, complete path for current flow [3] [16].

CONTINUOUS-WAVE KEYING

The on-off keying of a carrier [12].

CONTROL DIFFERENTIAL TRANSMITTER (CDX)

A type of synchro that transmits angular information equal to the algebraic sum or difference of the electrical input supplied to its stator, the mechanical input supplied to its stator, and the mechanical input supplied to its rotor. The output is an electrical voltage taken from the rotor windings [15].


CONTROL GRID

The electrode of a vacuum tube, other than a diode, upon which a signal voltage is impressed to regulate the plate current [6].


CONTROL SYNCHRO SYSTEMS

Synchro systems that contain control synchros and are used to control large amounts of power with a high degree of accuracy. The electrical outputs of these systems control servosystems, which in turn generate the required power to move heavy loads [15].


CONTROL SYSTEM

A group of components systematically organized to perform a specific control
purpose. These systems are categorized as either closed- or open-loop systems. The main difference between the two is that the closed-loop system contains some form of feedback [15].


CONTROL TRANSFORMER (CT)

A type of synchro that compares two signals: the electrical signal
applied to its stator and the mechanical signal applied to its rotor. The output is an electrical voltage, which is taken from the rotor winding and is used to control a power-amplifying device. The phase and amplitude of the output voltage depends on the angular position of the rotor with respect to the
magnetic field of the stator [15].


CONTROL TRANSMITTER (CX)

A type of synchro that converts a mechanical input, which is the
angular position of its rotor, into an electrical output signal. The output is taken from the stator windings and is used to drive either a CDX or CT [15].


CONTROL-GRID MODULATOR

Uses a variation of grid bias to vary the instantaneous plate voltage
and current. The modulating signal is applied to the control grid [12].


CONVERTER

In communications, equipment that changes the audio output of a receiver to dc pulses. These pulses are fed to a tty to indicate marks and spaces [17].


COOKIE-CUTTER TUNER

A mechanical magnetron tuning device that changes the frequency by
changing the capacitance of the anode cavities [11].


COPPER LOSS (I2R LOSS)

The power lost because of the resistance of the conductors. In transformers
the power lost because of current flow (I) through the resistance (R) of the windings [2] [10] [11].


CORDWOOD MODULE

A method of increasing the number of discrete components in a given space.
Resembles wood stacked for a fireplace [14].


CORE

Any material that affords a path for magnetic flux lines in a coil [2].

CORNER-REFLECTOR ANTENNA

A half-wave antenna with a reflector consisting of two flat metal surfaces meeting at an angle behind the radiator [10] [18].


CORONA

The discharge of electricity from a conductor with a high potential [4].

CORRECTIVE MAINTENANCE

Includes location and repair of equipment failures [16].

CORRESPONDENCE

The term given to the positions of the rotors of a synchro transmitter and a
synchro receiver when both rotors are on 0 degree or displaced from 0 degree by the same angle [15].


COULOMB

A measure of the quantity of electricity. One coulomb is equal to 6.28 x 1018 electrons [1].

COULOMB'S LAW

Also called the LAW OF ELECTRIC CHARGES or the LAW OF ELECTROSTATIC ATTRACTION. Coulomb's Law states that charged bodies attract or repel each
other with a force that is directly proportional to the product of their individual charges and inversely proportional to the square of the distance between them [1].


COUNTER

A circuit that counts input pulses [9].

COUNTER EMF

The voltage generated within a coil by a moving magnetic field cutting across the coil itself. This voltage is in opposition (counter) to the moving field that created it. Counter emf is present in every motor, generator, transformer, or other inductance winding whenever an alternating current flows [2] [5].


COUNTERPOISE

A network of wire connected to a quarter-wave antenna at one end. The network provides the equivalent of an additional one-fourth wavelength [10].


COUPLING

The process of transferring energy from one point in a circuit to another point, or from one circuit to another [8].


COUPLING CAPACITOR

A capacitor used to couple signals [8].

COUPLING DEVICE

A coupling coil that connects the transmitter to the feeder [10].

COVALENT BOND

A type of linkage between atoms in which the atoms share valence electrons [7].

CPR

Cardiopulmonary Resuscitation [1].

CREST (TOP)

The peak of the positive alternation (maximum value above the line) of a wave [10].

CRITICAL ANGLE

The maximum angle at which radio waves can be transmitted and still be refracted back to earth [10].


CRITICAL FREQUENCY

The maximum frequency at which a radio wave can be transmitted vertically
and still be refracted back to earth [10].


CROSS-SECTIONAL AREA

The area of a "slice" of an object. When applied to electrical conductors it
is usually expressed in circular mils [1].


CROSSED-FIELD AMPLIFIER

A high-power electron tube that converts dc to microwave power by a
combination of crossed electric and magnetic fields [18].


CROWN-OF-THORNS TUNER

See SPROCKET TUNER [11].

CRYSTAL

A natural substance, such as quartz or tourmaline, that is capable of producing a voltage when under physical stress or of producing physical movement when a voltage is applied [9].


CRYSTAL FURNACE

A device for artificially growing cylindrical crystals to be used in the production
of semiconductor substrates [14].


CRYSTAL MICROPHONE

A microphone that uses the piezoelectric effect of crystalline matter to
generate a voltage from sound waves [12].


CRYSTAL OVEN

A closed oven maintained at a constant temperature in which a crystal and its holder are enclosed to reduce frequency drift [9].


CURRENT

The movement of electrons past a reference point. The passage of electrons through a conductor. Measured in amperes [1].


CURRENT RATING

The safe current-carrying capacity of a wire or cable on a continuous basis [4].

CURRENT REGULATOR

A circuit that provides a constant current output [7].

CURRENT STANDING-WAVE RATIO (ISWR)

The ratio of maximum to minimum current along a transmission line [10].


CURRENT-FEED METHOD

Same as CENTER-FEED METHOD [10].

CUSPS

Sharp phase reversals [12].

CUTOFF

The condition in a tube or transistor whereby the reverse bias prevents current flow [13].

CUTOFF FREQUENCY

The frequency at which the attenuation of a waveguide increases sharply and
below which a traveling wave in a given mode cannot be maintained. A frequency with a half-wavelength that is greater than the wide dimension of a waveguide [11].


CW DEMODULATOR

A circuit that detects the presence of RF oscillations and converts them into a
useful form [12].


CYCLE

(1) One complete positive and one complete negative alternation of a current or voltage [2] [10]. (2) A 360-degree rotation of a vector generating a sine wave [12].


CYLINDRICAL PARABOLIC REFLECTOR

A parabolically shaped reflector that resembles part of a cylinder [18].



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