Neets Master Glossary

1-10 CATCHER GRID—In a velocity-modulated tube, a grid on which the spaced electron groups induce a signal. The output of the tube is taken from the catcher grid [11]. CATHODE—(1) In an electron tube the electrode that is the source of current flow [6]. (2) The general name for any negative electrode [1]. (3) The negative terminal of a forward-biased semiconductor diode, which is the source of the electrons [7]. CATHODE BIAS—The method of biasing a vacuum tube in which the biasing resistor is placed in the common-cathode return circuit, thereby making the cathode more positive with respect to ground [6]. CATHODE KEYING—A system in which the cathode circuit is interrupted so that neither grid current nor plate current can flow [12]. CATHODE MODULATOR—Voltage on the cathode is varied to produce the modulation envelope [12]. CATHODE-RAY TUBE (CRT)—An electron tube that has an electron gun, a deflection system, and a screen. This tube is used to display visual electronic signals [6]. CATHODE SPUTTERING—A process of producing thin film components [14]. CAVITY RESONATOR—A space totally enclosed by a metallic conductor and supplied with energy in such a way that it becomes a source of electromagnetic oscillations. The size and shape of the enclosure determine the resonant frequency [11]. CAVITY WAVEMETER—An instrument used to measure microwave frequencies [16]. CELL—A single unit that transforms chemical energy into electrical energy. Batteries are made up of cells [1]. CENTER-FEED METHOD—Connecting the center of an antenna to a transmission line which is then connected to the final (output) stage of the transmitter [10]. CENTIMETER CUBE—A unit of volume of large rectangular or square conductors. The cross-sectional area equals 1 square centimeter with a length of 1 centimeter [4]. CHANNEL—A carrier frequency assignment, usually with a fixed bandwidth [12]. CHARACTER—A letter, digit, or other symbol that is used as part of the organization, control, or representation of information [13]. CHARACTERISTIC IMPEDANCE—The ratio of voltage to current at any given point on a transmission line represented by a value of impedance [10]. CHARGE—Represents electrical energy. A material having an excess of electrons is said to have a negative charge. A material having a shortage of electrons is said to have a positive charge [1]. CHARGE CYCLE—The period of time that a capacitor in an electrical circuit is storing a charge [2]. CHOKE—An inductor used to impede the flow of pulsating dc or ac by means of self-inductance [6] [7]. CHOKE JOINT—A joint between two sections of waveguide that provides a good electrical connection without power losses or reflections [11]. CIRCUIT—The complete path of an electric current [1].