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ORIGIN—The point on a graph where the vertical and horizontal axes cross each other [10].
OSCILLATOR—An oscillator is a nonrotating device that produces alternating current. The frequency is
determined by the characteristics of the device [9].
OUT-OF-CIRCUIT METER—A meter that is not permanently installed in a circuit. Usually portable and
self-contained, these meters are used to check the operation of a circuit or to isolate troubles within a
circuit [3].
OUTPUT END—The end of a transmission line that is opposite the source; receiving end [10].
OUTPUT IMPEDANCE—The impedance that is presented to the load by the transmission line and its
source [10].
OVERDRIVEN—When the input signal amplitude is increased to the point that the transistor goes into
saturation and cutoff [7].
OVERMODULATION—A condition that exists when the peaks of the modulating signal are limited [12].
PACKAGING LEVELS—A system developed to assist maintenance personnel in determining the
repairability of components, printed circuit boards, modules, and so forth [14].
PAGE PRINTER—A high-speed printer that prints teletypewriter characters one at a time in a full-page
format [17].
PARABOLIC REFLECTOR—An antenna reflector in the shape of a parabola. It converts spherical
wavefronts from the radiating element into plane wavefronts [18].
PARALLAX ERROR—The error in meter readings that results when you look at a meter from some
position other than directly in line with the pointer and meter face. A mirror mounted on the meter face
aids in eliminating parallax error [3].
PARALLEL CIRCUIT—Two or more electrical devices connected to the same pair of terminals so
separate currents flow through each; electrons have more than one path to travel from the negative to
the positive terminal [1].
PARALLEL-CONNECTED DUPLEXER—Configuration in which the tr spark gap is connected across
the two legs of the transmission line one-quarter wavelength from the T-junction [18].
PARALLEL LIMITER—A resistor and diode, connected in series with the input signal, in which the
output is taken across (parallel to) the diode [9].
PARALLEL-NEGATIVE LIMITER—A resistor and diode, connected in series with the input signal, in
which the output is taken across the diode and the negative alternation is eliminated [9]
PARALLEL-POSITIVE LIMITER—A resistor and diode connected in series with the input signal, in
which the output is taken across the diode and the positive alternation is eliminated [9].
PARALLEL-RESONANT CIRCUIT—A resonant circuit in which the source voltage is connected across
a parallel circuit (formed by a capacitor and an inductor) to furnish a high impedance to the frequency
at which the circuit is resonant. Often referred to as a tank circuit [9] [10].
PARALLEL-WIRE—A type of transmission line consisting of two parallel wires [10].
