APPENDIX I GLOSSARY

AI-2 FREQUENCY DEVIATION—Refers to the difference between the carrier frequency of an fm signal and the instantaneous frequency of its modulated wave. FREQUENCY DOMAIN—A plot of frequency versus amplitude as shown by a spectrum analyzer display. FREQUENCY RESPONSE—(I) The ability of a component or device to operate over a portion of the frequency spectrum. (2) In reference to test equipment, that portion of the frequency spectrum that the test equipment is capable of sensing and measuring accurately. GALVANOMETER—A meter used to measure small values of current by electromagnetic or electrodynamic means. IMPEDANCE ANGLE METER—A device that measures circuit impedance by comparing the phase angle between voltage and current. INSERTION LOSS—The difference between the amount of power applied to a load before and after the insertion of a device in the line. INTEGRATED CIRCUIT (IC)—(1) A circuit in which many elements are fabricated and interconnected by a single process (into a single chip), as opposed to a nonintegrated circuit in which the transistors, diodes, resistors, and other components are fabricated separately and then assembled. (2) Elements inseparably associated and formed on or within a single substrate. INTERMODULATION DISTORTION—Nonlinear distortion characterized by the appearance (at the system output) of frequencies equal to the sums and differences of two or more frequencies present at the input. LOAD—(I) A device through which an electric current flows that changes electrical energy into another form. (2) Power consumed by a device or circuit in performing its function. LOGIC CLIPS—A device that can be clipped onto an in-circuit, dual-in-line package (DIP) logic IC to determine the logic state of each pin of the IC. LOGIC PROBE—A hand-held probe used to determine the logic state (high or low) of test points in a logic circuit. A logic high is represented by a lit indicator light on the probe. LOGIC PULSER—A hand-held probe used to pulse, or change the logic state, of in-circuit logic ICs. METROLOGY CALIBRATION (METCAL) PROGRAM—A Navy calibration program designed to ensure the accuracy of test equipment through comparisons with calibration laboratory standards of known accuracy. MICROPHONICS—Electrical noise caused by the mechanical motion of the internal parts of a device. The term is usually associated with vacuum tubes. MODULATION INDEX—When a sine wave is used to modulate an fm signal, the ratio of the frequency deviation to the frequency of the modulating wave.