NAND A logic function of A and B that is true if either A or B is false [13].

NAND CIRCUIT A combination of a NOT function and an AND function in a binary circuit that has two or more inputs and one output. The output is logic 0 only if ALL inputs are logic 1; it is logic 1 if ANY input is logic 0 [13].

NATURAL FREQUENCY See RESONANT FREQUENCY [9].

NATURAL HORIZON The line-of-sight horizon [10].

NAUTICAL MILE The length of a minute of arc of a great circle of the earth (6,076 ft) [18].

NAUTICAL RADAR MILE See RADAR MILE [18].

NEAR SYNCHRONOUS ORBIT An orbit in which the satellite rotates close to but not exactly at the same speed as the earth [17].

NEGATION The process of inverting the value of a function or variable [13].

NEGATIVE ALTERNATION That part of a sine wave that is below the reference level [2] [10] [12].

NEGATIVE CLAMPER A circuit that clamps the upper extremity of the output waveshape to a dc potential of 0 volts [9].

NEGATIVE ELECTRODE A terminal or electrode having more electrons than normal. Electrons flow out of the negative terminal of a voltage source [1].

NEGATIVE FEEDBACK Feedback in which the feedback signal is out of phase with the input signal. Also called DEGENERATIVE FEEDBACK [8].

NEGATIVE LOGIC The form of logic in which the more positive voltage level represents a logic 0, FALSE, or LOW and the more negative voltage represents a logic 1, TRUE, or HIGH [13].

NEGATIVE TEMPERATURE COEFFICIENT A characteristic of a semiconductor material, such as silver sulfide, in which resistance to electrical current flow decreases as temperature increases [1] [4] [7].

NEGATIVE-RESISTANCE ELEMENT A component having an operating region in which an increase in the applied voltage increases the resistance and produces a proportional decrease in current. Examples include tunnel diodes and silicon unijunction transistors [11].

NETWORK A combination of electrical components. In a parallel circuit it is composed of two or more branches [1].

NEUTRAL (1) In a normal condition, hence neither positive nor negative. A neutral object has a normal number of electrons (the same number as protons) [1]. (2) The teletypewriter operation where current flow represents a mark and no flow represents a space [17].

NEUTRALIZATION The process of counteracting or "neutralizing" the effects of interelectrode capacitance [8].

NEWTON'S SECOND LAW OF MOTION If an unbalanced outside force acts on a body, the resulting acceleration is directly proportional to the magnitude of the force, is in the direction of the force, and is inversely proportional to the mass of the body [15].

NO-LOAD CONDITION The condition that exists when an electrical source or secondary of a transformer is operated without an electrical load [2].

NODE The fixed minimum points of voltage or current on a standing wave or antenna [10].

NOISE (1) In reference to sound, an unwanted disturbance caused by spurious waves that originate from man-made or natural sources [10]. (2) In radar, erratic or random deflection or intensity of the indicator sweep that tends to mask small echo signals [18].

NOISE FIGURE The ratio of output noise to input noise in a receiver [18].

NOISE LIMITER Circuit that clips the peaks of the noise spikes in a receiver [17].

NOISE SILENCER See NOISE LIMITER [17].

NOISE SUPPRESSOR See NOISE LIMITER [17].

NONDEGENERATIVE PARAMETRIC AMPLIFIER A parametric amplifier that uses a pump signal frequency that is higher than twice the frequency of the input signal [11].

NONDIRECTIONAL See OMNIDIRECTIONAL [10].

NONLINEAR DEVICE A device in which the output does not rise and fall in direct proportion to the input [6] [7] [12].

NONLINEAR IMPEDANCE An impedance in which the resulting current through the device is not proportional to the applied voltage [12].

NONLUMINOUS BODIES Objects that either reflect or diffuse light that falls upon them [10].

NONRESONANT LINE A transmission fine that has no standing waves of current or voltage [10].

NONTRIP-FREE CIRCUIT BREAKER A circuit breaker that can be held in the ON position during an overcurrent condition [3].

NOR A logic function of A and B that is true if both A and B are false [13].

NOR GATE An OR gate that is followed by an inverter to form a binary circuit in which the output is a logic 0 if ANY of the inputs is a logic 1 and the output is a logic 1 only if ALL the inputs are a logic 0 [13].

NORMAL The imaginary line perpendicular to the point at which the incident wave strikes the reflecting surface. Also called the perpendicular [10].

NOT CIRCUIT A binary circuit with a single output that is always the opposite of the input. Also called an INVERTER CIRCUIT [13].

NPN An NPN transistor is formed by introducing a thin region of P-type material between two regions of N-type material [7].

NULL On a polar-coordinate graph, the area that represents minimum or 0 radiation [10].

NUMBER (1) A mathematical entity that may indicate quantity or amount of units. (2) Loosely, a numeral. An abstract mathematical symbol for expressing a quantity. In this sense, the manner of representing the number is immaterial. Take 26, for example; this is its decimal form - but it could be expressed as a binary (base 2), octal (base 8), or hexadecimal (base 16) number [13].

NUMBER REPRESENTATION The representation of numbers by agreed sets of symbols according to agreed rules [13].

NUMBER SYSTEM Loosely, a number representation system. Any system for the representation of numbers (see POSITIONAL NOTATION) [13].

NUMERAL (1) A discrete representation of a number. For example, twelve, 12, XII, 11002 are four different numerals that represent the same number. (2) A numeric word that represents a number [13].

NUTATING Moving an antenna feed point in a conical pattern so that the polarization of the beam does not change [18].