CIRCULAR MILAn 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 .
CIRCULAR MIL-FOOTA unit of volume of a conductor having a cross-sectional area of 1 circular mil
and a length of 1 foot .
CLAMPERA circuit in which either the upper or lower extremity of a waveform is fixed at a desired
CLASS A AMPLIFIER OPERATIONThe type of operation in which the amplifier is biased so that
variations in input signal polarities occur within the limits of cutoff and saturation .
CLASS AB AMPLIFIER OPERATIONThe 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 .
CLASS B AMPLIFIER OPERATIONThe type of operation in which the amplifier is biased so that
collector current is cut off for one-half of the input signal .
CLASS C AMPLIFIER OPERATIONThe 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  .
CLUTTERConfusing, unwanted echoes that interfere with the observation of desired signals on a radar
COAXIAL CABLECable in which the center conductor is separated from an outer conductor by a
dielectric material; used in RF transmission .
COAXIAL LINEA type of transmission line that contains two concentric conductors .
CODEIn teletypewriter operation, code is a combination of mark and space conditions representing
symbols, figures, or letters .
COEFFICIENT OF COUPLINGAn 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 .
COHERENCEA definite phase relationship between two energy waves, such as transmitted frequency
and reference frequency .
COHERENTRadiation on one frequency .
COHERENT OSCILLATORIn cw radar an oscillator that supplies phase references to provide coherent
video from target returns .
COILAn inductive device made by looping turns of wire around a core .
COLD-CATHODE TUBEA gas-filled electron tube that conducts without the use of filaments. Cold-
cathode tubes are used as voltage regulators .
COLLECTORThe element in a transistor that collects the current carriers .
COLLECTOR-INJECTION MODULATORThe transistor equivalent of a plate modulator.
Modulating voltage is applied to a collector circuit .