Neets Master Glossary

1-16 CURRENT STANDING-WAVE RATIO (ISWR)—The ratio of maximum to minimum current along a transmission line [10]. CUSPS—Sharp phase reversals [12]. CUTOFF—The condition in a tube or transistor whereby the reverse bias prevents current flow [13]. CUTOFF FREQUENCY—The frequency at which the attenuation of a waveguide increases sharply and below which a traveling wave in a given mode cannot be maintained. A frequency with a half- wavelength that is greater than the wide dimension of a waveguide [11]. CW DEMODULATOR—A circuit that detects the presence of RF oscillations and converts them into a useful form [12]. CYCLE—(1) One complete positive and one complete negative alternation of a current or voltage [2] [10]. (2) A 360-degree rotation of a vector generating a sine wave [12]. CYLINDRICAL PARABOLIC REFLECTOR—A parabolically shaped reflector that resembles part of a cylinder [18]. DAMPED WAVE—A sinusoidal wave in which the amplitude steadily decreases with time. Often associated with energy loss [9]. DAMPING—(1) The process of smoothing out oscillations. (2) In a meter, this process is used to keep the pointer of the meter from overshooting the correct reading [3]. (3) A mechanical or electrical technique used in synchro receivers to prevent the rotor from oscillating or spinning. Damping is also used in servosystems to minimize overshoot of the load [15] [16]. D'ARSONVAL METER MOVEMENT—The permanent-magnet moving-coil movement used in most meters [3] [16]. DATA PROCESSING—The execution of a systematic sequence of operations performed upon data. Synonymous with information processing [13]. DATA TRANSMISSION—The transfer of information from one place to another or from one part of a system to another [15]. dBm—An abbreviation used to represent power levels above or below a 1-milliwatt reference [16]. DEAD SHORT—A short circuit having minimum resistance [1]. DECIMAL—Pertaining to the number representation system with a radix of ten [13]. DECIMAL DIGIT—In decimal notation, one of the characters 0 through 9 [13]. DECIMAL NOTATION—A fixed radix notation where the radix is ten [13]. DECIMAL NUMERAL—A decimal representation of a number [13]. DECIMAL POINT—The radix point in decimal representation [13]. DECOUPLING CAPACITOR—A capacitor used to transfer unwanted signals out of a circuit; for example, coupling an unwanted signal to ground. Also called a BYPASS CAPACITOR [8]. DEFLECTION COILS—In a cathode-ray tube, coils used to bend an electron beam a desired amount [18].