N

NAB (organization) Abbreviation for National Association of Broadcasters. For several years, prior to January 1, 1958, it was known as National Association of Radio and Television Broadcasters (NARTB).

nail head bonding (process/IC) A synonym for ball bonding.

nano- (prefix) A prefix meaning 10 -9, which is 0.000000001 or one billionth.

nanosecond (measurement) One billionth of a second.

narrow-band EMI (electrical) EMI generated from a device operating at a specific and limited range of frequencies.

See also EMI.

Natural Rubber (NR-isoprene) (material) Rubber by itself is lacking in many properties required of wire and cable insulating and jacketing materials. However, by proper compounding and mixing with other products, it can be converted to a material with excellent physical properties, good electrical properties, and fair to moderate ozone resistance and chemical resistance.

NBR (abbreviation) See Nitrile-Butadiene Rubber.

NBR/PVC (abbreviation/material) A blend of nitrile rubber and polyvinyl chloride, is recommended for oil and ozone resistant jacketing of flexible cord and fixture wires, cables, and ignition wires. NBR/PVC is said to offer toughness, smoothness, flame resistance, flexibility, and resistance to abrasion and heat deformation, and to give outstanding service when exposed to weather, light, fuel, oil, or ozone.

NC normally closed contacts (device/circuit) See NO or NC contacts.

Near End Crosstalk (NEXT)--Signal distortion as a result of signal coupling from one pair to another at various frequencies.

NEC (abbreviation) Abbreviation for National Electric Code.

NEMA (organization) Abbreviation for National Electrical Manufacturers Association.

neon (general) An inert element from Group O of the periodic table of chemical elements. Exists as a gas at normal temperatures and pressures. When ionized by current passing through it, as in neon signs, bulbs, pilot lights, test probes, etc, it produces a bright orange-red glow.

neoprene rubber (material) A synthetic rubber used for a wide variety of wire and cable jacketing applications. The physical properties are similar to natural rubber but with better resistance to oil, ozone, heat, weather, and aging. It does not support combustion and resists abrasion and cutting.

network-leased line (communication) May refer to either a telephone or teletype network; usually has reference to telephone lines.

network-private wire (communication) May refer to either private telephone or private teletype network.

network-telephone (communication) A system of points interconnected by private voice-grade telephone whereby direct point-to-point telephone communications are provided. This traffic usually bypasses commercial switching facilities; the customer provides his own operating personnel for leased lines and facilities. Service is available from local common carriers.

network-teletype (communication) A system of points, interconnected by private telegraph channels - which provide hard copy and/or telegraphic coded (five-channel) punched paper tape - at both sending and receiving points. Typically, up to 20 way stations share send-receive time on a single circuit. If two or more circuits are provided, a switching center is required to permit cross circuit transmission.

Nitrile-Butadiene Rubber (NBR) (material) Specific properties depend on the actual composition but generally, this rubber offers excellent resistance to oils and solvents.

NMOS (abbreviation/component) N-channel metal-oxide semiconductor. A MOS IC using n-type material for the channels.

node

(electrical) - A zero point. Specifically, a current node is a point of zero current; a voltage node is a point of zero voltage.

(network) - An end point to any branch of a network or a junction common to two or more branches. Terminals and other equipment that communicate over the network are nodes in a network.

noise (circuit/system) An extraneous signal in an electrical circuit, capable of interfering with the desired signal. Loosely, any disturbance tending to interfere with the normal operation of a device or system. Classes of noise include burst or popcorn noise, intermediate frequency noise at low audio frequencies, white (thermal) noise, etc. Signals from power supply or ground line coupled into an amplifier output may be considered noise.

NO or NC contacts (device/circuit) Normally Open or Normally Closed, meaning the state of the contacts when the control circuit is not energized.

npn transistor (component/circuit) A bipolar transistor having a p-type base between an n-type emitter and an n-type collector. The emitter should be negative with respect to the base, and the collector should be positive with respect to the base.

N Series (connector) A large radio frequency connector covered by Military Specification. It has an impedance of 50ohms, and is designed to operate in the 0 to 11 GHz frequency range. It has a threaded coupling and is physically larger than a TNC connector.

ntc (abbreviation) Negative temperature coefficient.

numerical aperture (fiber optic) The light gathering ability of a fiber, defined as the sine of half the angle that contains 90% of the optical power that is captured by the fiber. Controlled by a specific code to cladding refractive indices.

nylon (material) The generic name for synthetic fiber- forming polyamides. Available in three forms for wires and cables: as a yarn for wire sleeving and braid; as an extrusion material (primarily for jackets); and as a coating.