"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"
RACE CONDITION. defines a condition when a device's output depends on two or more nearly simultaneous events to occur at the input. Logic Race Conditions.
RACEWAY. A channel designed expressly for holding wires, cables, or busbars, with additional
functions as permitted in this subpart. Raceways may be of metal or insulating material, and the term
includes rigid metal conduit, rigid nonmetallic conduit, intermediate metal conduit, liquidtight
flexible metal conduit, flexible metallic tubing, flexible metal conduit, electrical metallic tubing,
underfloor raceways, cellular concrete floor raceways, cellular metal floor raceways, surface
raceways, wireways, and busways.
RADAR. An acronym for RAdio Detecting And Ranging. Refer to the Dictionary of Radar Terms
RADAR ALTIMETER. Airborne radar that measures the distance of the aircraft above the ground.
RADAR BEAM.The space in front of a radar antenna where a target can be effectively detected or
tracked. Defined by areas that contain half or more of the maximum power transmitted.
RADAR DETECTOR. A detector that, in its simplest form, only needs to be capable of producing an
output when RF energy (reflected from a target) is present at its input.
RADAR DISTRIBUTION SWITCHBOARD. An electrical switching panel used to connect inputs from
any of several radars to repeaters (indicators).
RADAR MILE. Time interval (12.36 microseconds) for RF energy to travel out from a radar to a target
and back to the radar; radar nautical mile.
RADAR TEST SET. A combination of several test circuits and equipment used to test various
characteristics of a radar.
RADIATION FIELD. The electromagnetic field that radiates from an antenna and travels through space.
RADIATION LOSSES. The losses that occur when magnetic lines of force about a conductor are
projected into space as radiation and are not returned to the conductor as the cycle alternates.
RADIATION PATTERN. A plot of the radiated energy from an antenna.
RADIATION RESISTANCE. The resistance that if inserted in place of the antenna would consume the
same amount of power as that radiated by the antenna.
RADIATION, Space. Radiation from space. Refer to the Space Radiation Dictionary.
RADIO COMMUNICATIONS. The term describing teletypewriter, voice, telegraphic, and facsimile
communications.
RADIO FREQUENCY (RF). Any frequency of electromagnetic energy capable of propagation into
space. The frequencies that fall between 3 kilohertz and 300 gigahertz used for radio
communications.
RADIO FREQUENCY CARRIER SHIFT. The system that uses a keyer to shift a radio frequency signal
above or below an assigned frequency. These shifts correspond to marks and spaces.
RADIO HORIZON. The boundary beyond the natural horizon in which radio waves cannot be propagated
over the earth’s surface.
RADIO SET CONTROL UNIT. Equipment used to remotely control certain transmitter and receiver
functions.
RADIO WAVES. A form of radiant energy that can neither be seen nor felt. An electromagnetic
wave that is generated by a transmitter.
RADIX. Also called the base. The number of distinct symbols used in a number system. For example,
since the decimal number system uses ten symbols (0, 1, 2, 3, 4, 5, 6, 7, 8, 9), the radix is 10. In the
binary number system, the radix is 2 because it uses only two symbols (0, 1).
RADIX POINT. Also called BINARY POINT, OCTAL POINT, DECIMAL POINT, and so forth,
depending on the number system.
Next set of "R" Terms
