RADAR DETECTORA 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 SWITCHBOARDAn electrical switching panel used to connect inputs from
any of several radars to repeaters (indicators) .
RADAR MILETime 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 SETA combination of several test circuits and equipment used to test various
characteristics of a radar .
RADIATION FIELDThe electromagnetic field that radiates from an antenna and travels through space
RADIATION LOSSESThe 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 PATTERNA plot of the radiated energy from an antenna .
RADIATION RESISTANCEThe resistance that if inserted in place of the antenna would consume the
same amount of power as that radiated by the antenna .
RADIO COMMUNICATIONSThe term describing teletypewriter, voice, telegraphic, and facsimile
RADIO FREQUENCY (RF)(1) Any frequency of electromagnetic energy capable of propagation into
space . (2) The frequencies that fall between 3 kilohertz and 300 gigahertz used for radio
RADIO FREQUENCY CARRIER SHIFTThe 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 HORIZONThe boundary beyond the natural horizon in which radio waves cannot be propagated
over the earth's surface .
RADIO SET CONTROL UNITEquipment used to remotely control certain transmitter and receiver
RADIO WAVES(1) A form of radiant energy that can neither be seen nor felt. (2) An electromagnetic
wave that is generated by a transmitter .
RADIXAlso 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 POINTAlso called BINARY POINT, OCTAL POINT, DECIMAL POINT, and so forth,
depending on the number system .
RANGEThe length of a straight line between a radar set and a target  .
RANGE-GATEA movable gate used to select radar echoes from a very short range interval .