"A"
"B"
"C",
"D",
"E",
"F",
"G",
"H",
"I",
"J",
"K",
"L",
"M",
"N",
"O",
"P",
"Q",
"R",
"S",
"T",
"U",
"V",
"W",
"X",
"Y",
"Z"
Previous set of "R" Terms and definitions
RANGE. The length of a straight line between a radar transmitter and a target. [Radar Terms]
RANGE-GATE. A movable gate used to select radar echoes from a very short range interval.
RANGE-HEIGHT INDICATOR. A radar display on which slant range is shown along the X axis and
height along the Y axis.
RANGE MARKER. A movable vertical pulse on an A-scope or a ring on a PPI scope used to measure the
range of an echo or to calibrate the range scale.
RANGE RESOLUTION. Ability of a radar to distinguish between targets that are close together.
RANGES. The several upper limits a meter will measure as selectable by a switch or by jacks; for
example, a voltmeter may have ranges of 1 volt, 2.5 volts, 10 volts, 25 volts, and 100 volts.
RANGE STEP. On an A-scope sweep, a vertical displacement used to measure the range of an echo.
RAREFIED WAVE. A longitudinal wave that has been expanded or rarefied (made less dense) as it
moves away from the source.
RATE GYRO. A gyro used to detect and measure angular rates of change.
RATIO. The value obtained when one number is divided by another. This value indicates the relative
proportions of the two numbers.
RATIO DETECTOR. A detector that uses a double-tuned transformer to convert the instantaneous
frequency variations of the FM input signal to instantaneous amplitude variations.
RATIO OF TRANSMITTED POWERS. The power ratio (FSK versus AM) that expresses the overall
improvement of FSK transmission when compared to AM under rapid-fading and high-noise conditions.
RC CONSTANT. Time constant of a resistor-capacitor circuit; equal in seconds to the resistance value in
ohms multiplied by the capacitance value in farads. [RC Voltage Graph]
RC DIFFERENTIATOR. An RC circuit in which the output is taken from the resistor.
RC FILTER. A filter used in applications where load current is low and constant, and voltage regulation is
not necessary. An RC filter is comprised of some number of Resistors and Capacitors
RC INTEGRATOR. An RC circuit in which the output is taken from the capacitor.
RC NETWORK. A circuit containing resistance and capacitance arranged in a particular manner to
perform a specific function.
RC OSCILLATOR. An oscillator in which the frequency is determined by resistive and capacitive
elements. [Oscillator Manufacturers]
REACTANCE. The opposition offered to the flow of an alternating current by the inductance,
capacitance, or both, in any circuit.
REACTANCE AMPLIFIER. A low-noise amplifier that uses a nonlinear variable reactance as the active
element instead of a variable resistance. Also called a parametric amplifier.
REACTANCE TUBE. A tube connected in parallel with the tank circuit of an oscillator. Provides a signal
that will either lag or lead the signal produced by the tank.
REACTANCE-TUBE MODULATOR. An FM modulator that uses a reactance tube in parallel with the
oscillator tank circuit.
Next set of "R" Terms
