RESISTORThe electrical component that offers resistance to the flow of current. It may be a coil of fine
wire or a composition rod .
RESOLVERA rotary, electromechanical device used to perform trigonometric computations by varying
the magnetic couplings between its primary and secondary windings. It is generally used in circuits that
solve vector problems, such as analog computers and conversion equipment. The resolver solves three
different type problems: (1) Resolution - separating a vector into two mutually perpendicular
components; (2) Composition - combining two components of a vector to produce a vector sum; and (3)
Combination - the process of resolution and composition taking place simultaneously .
RESONANCEThe condition in a circuit containing inductance and capacitance in which the inductive
reactance is equal and opposite to the capacitive reactance. This condition occurs at only one frequency
and the circuit in that condition is said to be in resonance   .
RESONANCE CHAMBERSee ECHO BOX .
RESONANT CIRCUITA circuit that contains both inductance and capacitance and is resonant at one
frequency (XL = XC) .
RESONANT FREQUENCYThat frequency in a given resonant circuit at which the inductive and
capacitive reactance values are equal and cancel each other .
RESONANT LINEA transmission line that has standing waves of current and voltage .
REST FREQUENCYThe carrier frequency during the constant-amplitude portions of a phase
modulation signal .
REST POSITIONSee REFERENCE LINE .
REST TIME (RT)The time when there is no pulse; nonpulse time .
RESULTANT MAGNETIC FIELDThe magnetic field produced in a synchro by the combined effects
of the three stator magnetic fields .
RETENTIVITYThe ability of a material to retain its magnetism .
RETURNThe RF signal reflected back from a radar target; echo .
REVERBERATIONThe multiple reflections of sound waves .
REVERSE AGCThe type of AGC that causes an amplifier to be driven toward cut-off .
REVERSE BIASAn external voltage applied to a diode or semiconductor junction to reduce the flow of
electrons across the junction. Also called BACK BIAS  .
RF RADIATION HAZARDA health hazard caused by exposure to electromagnetic radiation or high-
energy particles (ions). Abbreviated RADHAZ .
RF (RADIO FREQUENCY) AMPLIFIERAn amplifier designed to amplify signals with frequencies
between 10 kilohertz (10 kHz) and 100,000 megahertz (100,000 MHz) .
RF (RADIO FREQUENCY) TRANSFORMERA transformer specially designed for use with RF (radio
frequencies). An RF transformer is wound onto a tube of nonmagnetic material and has a core of either
powdered iron or air .