Neets Master Glossary

1-54 PICO—A prefix adopted by the National Bureau of Standards meaning 10 -12 [1]. PICTORIAL DIAGRAM—A diagram showing actual pictorial sketches of the various parts of an equipment and the electrical connections between the parts [4]. PIEZOELECTRIC EFFECT—The effect of producing a voltage by placing a stress, either by compression, expansion, or twisting, on a crystal and, conversely, producing a stress in a crystal by applying a voltage to it [1]. PIP (BLIP)—On a CRT display, a spot of light or a baseline irregularity representing the radar echo [18]. PITCH—A term used to describe the frequency of a sound heard by the human ear [10]. PLANAR TUBE—An electron tube, constructed with parallel electrodes and a ceramic envelope, that is used at uhf frequencies. It is commonly referred to as a lighthouse tube [6]. PLANE OF POLARIZATION—The plane (vertical or horizontal), with respect to the earth, in which the E field propagates [10]. PLANE WAVEFRONTS—Waves of energy that are flat, parallel planes and are perpendicular to the direction of propagation [18]. PLANNED-POSITION INDICATOR—A radar display in which range is indicated by the distance of a bright spot or pip from the center of the screen and the bearing is indicated by the radial angle of the spot [18]. PLATE—(1) One of the electrodes in a storage battery [1]. (2) One of the electrodes in a capacitor [2]. (3) The principal electrode to which the electron stream is attracted in an electron tube [6]. PLATE DISSIPATION—The amount of power lost as heat in the plate of a vacuum tube [6]. PLATE KEYING—A keying system in which the plate supply is interrupted [12]. PLATE MODULATOR—An electron-tube modulator in which the modulating voltage is applied to the plate circuit of the tube [12]. PLATE RESISTANCE—The plate voltage change divided by the resultant plate current change in a vacuum tube, all other conditions being fixed [6]. POINT BENDER—A tool used to adjust the contact spacing on a relay [3]. POINT-CONTACT DIODE—A diode in which the end of a fine wire is pressed against a semiconductor. Used as a detector or mixer over the microwave region [7]. POINT OF ZERO DISPLACEMENT—See REFERENCE LINE [10]. POINT-TO-POINT WIRING—Individual wires run from terminal to terminal to complete a circuit [14]. POLAR—The teletypewriter operation in which current flow of one polarity represents a mark, and current of the opposite polarity represents a space [17]. POLAR-COORDINATE GRAPH—A graph with a pair of axes. One consists of a series of circles with a common center, and the other consists of a rotating radius extending from the center of the concentric circles [10].