1-81
UNIVERSAL TIME CONSTANT CHART—A chart used to find the time constant of a circuit if the
impressed voltage and the values of R and C or R and L are known [2].
UNTUNED LINE—Another name for the flat or nonresonant line [10].
UP LINK—The frequency used to transmit a signal from earth to a satellite [17].
UPPER-FREQUENCY CUTOFF—The highest frequency a circuit can pass [9].
UPPER SIDEBAND—All of the sum frequencies above the carrier [12].
VACUUM EVAPORATION—Process of producing thin film components [14].
VALENCE—The measure of the extent to which an atom is able to combine directly with other atoms. It
generally depends on the number and arrangement of the electrons in the outermost shell of the atom
[1].
VALENCE SHELL—The electrons that form the outermost shell of an atom [1].
V ANTENNA—A bidirectional antenna, shaped like a V, which is widely used for communications [10].
VAR—Abbreviation for volt-amperes reactive [2].
VARACTOR—A PN junction semiconductor, designed for microwave frequencies, in which the
capacitance varies with the applied voltage [7] [11] [12].
VARACTOR FM MODULATOR—An FM modulator that uses a voltage-variable capacitor (varactor)
[12].
VARIABLE—A representative symbol that can assume any of a given set of values [13].
VARIABLE ATTENUATOR—An attenuator for reducing the strength of an ac signal either continuously
or in steps, without causing signal distortion [11].
VARIABLE-MU-TUBE—Same as REMOTE-CUTOFF TUBE [6].
VARIABLE RESISTOR—A wire-wound or composition resistor, the value of which may be changed over
a designed range [1].
VARNISHED CAMBRIC—Cotton cloth coated with insulation varnish. An insulation used on high-
voltage conductors [4].
VECTOR—A line used to represent both direction and magnitude [2] [12].
VEITCH DIAGRAM—A diagram consisting of joined squares, which is used to give a graphic
representation of basic logic relations [13].
VELOCITY—The rate at which a disturbance travels through a medium [10].
VELOCITY MODULATION—Modification of the velocity of an electron beam by the alternate
acceleration and deceleration of electrons [11].
VELOCITY SERVOSYSTEM—A servosystem which controls the speed of the load it is driving [15].
VERTICAL AXIS—On a graph, the straight line axis that is plotted from bottom to top [10].
