Neets Master Glossary

1-6 BANDPASS FILTER—A filter that allows a narrow band of frequencies to pass through the circuit. Rejects or attenuates frequencies that are either higher or lower than the desired band of frequencies [9] [16]. BAND-REJECT FILTER—A tuned circuit that does not pass a specified band of frequencies [9] [16]. BANDWIDTH—The difference between the highest usable frequency of a device (upper frequency limit) and the lowest usable frequency of the device (lower frequency limit) - measured at the half-power points [8] [9] [12] [15]. BARRETTER—A type of bolometer characterized by an increase in resistance as the dissipated power rises [16]. BASE—The element in a transistor that controls the flow of current carriers [7]. BASE—(1) A reference value. (2) A number that is multiplied by itself as many times as indicated by an exponent. (3) Same as radix. (4) The region between the emitter and collector of a transistor that receives minority carriers injected from the emitter. It is the element that corresponds to the control grid of an electron tube [13]. BASE-INJECTION MODULATOR—Similar to a control-grid modulator. The gain of a transistor is varied by changing the bias on its base [12]. BATTERY—A device for converting chemical energy into electrical energy [1]. BATTERY CAPACITY—The amount of energy available from a battery. Battery capacity is expressed in ampere-hours [1]. BAUD—A measurement of speed based on the number of code elements or units per second [17]. BAY—Part of an antenna array [10]. BEAM—See LOBE [18]. BEAM-LEAD CHIP—Semiconductor chip with electrodes (leads) extended beyond the wafer [14]. BEAM-POWER TUBE—An electron tube in which the grids are aligned with the control grid. Special beam-forming plates are used to concentrate the electron stream into a beam. Because of this action, the beam-power tube has high power-handling capabilities [6]. BEARING—An angular measurement of the direction of an object from a reference direction, such as true north [11]. BEARING RESOLUTION—Ability of a radar to distinguish between targets that are close together in bearing [18]. BEAT FREQUENCIES—Difference and sum frequencies, which result from the combination of two separate frequencies [18]. BEAT FREQUENCY—The difference between the oscillator frequency and the unknown audio frequency [16]. BEAT-FREQUENCY OSCILLATOR—An additional oscillator used in a receiver when it is receiving a cw signal. It provides an audible tone [17].