Glossary

A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | R | S | T | U | V | W | Y

A

Abrasion – Damage caused by scraping or rubbing against a rough, hard surface.

Abrasion Resistance –A measure of the ability of a wire, wire covering or material to resist surface wear or damage by mechanical means.

A.C.– Abbreviation for alternating current.

Admittance – The measure of ease with which an alternating current flows in a circuit. The reciprocal of impedance.

Alloy – A metal formed by combining two or more other metals.

Alternating Current – Electrical current that periodically and regularly reverses its direction. The frequency of the Change in flow is expressed in cycles per second (Hertz or Hz)

Ambient Temperature – The temperature of a medium, such as a gas or liquid, surrounding an object.

American Wire Gauge (AWG) – The standard system used for designating wire diameter.

Ampere – A standard unit of current. Designated as the amount of current that occurs when one volt of emf is applied across one ohm of resistance. An ampere of current is produced by one coulomb of charge passing a point in one second.

Ampere’s Rule – Current in a certain direction is equivalent to the motion of positive charges in that direction. The magnetic flux generated by a current in the counter-clockwise direction when it is approaching the observer.

Analog – Representation of data by continuously variable quantities.

Anneal – To heat and then gradually cool in order to relieve mechanical stresses. Annealing copper makes it softer and less brittle.

Annealed Wire – Wire which has been softend by heating. Sometimes referred to as soft drawn wire.

Arc Resistance – Time required for an arc to establish a conductive path in a material. Breakdown between two electrodes usually occurs as a conducting path is burned on the surface of the dielectric material.

ASTM – Abbreviation for American Society for Testing and Materials.

Attenuation – Power loss in an electrical system. Applied to coaxial cables, the power drop or signal loss in a circuit, expressed in decibels, db. It is also the decrease in amplitude of a wave with distance in the direction of wave propagation when the time or the decrease in amplitude with time at a given place. Attenuation is generally expressed in db per unit, usually 1000 ft., and is indicative of the power loss.

AWG – Abbreviation for American Wire Gauge.

B

Bandwidth – The difference between the upper and lower limits of a given band of frequencies. Expressed in Hertz.

Bare Conductor – A conductor not covered in an insulating material.

Bare Copper (B.C.) – A copper conductor that is not plated.

Baud – Unit of data transmission speed meaning bits per second. 500 baud = 500 bits per second.

Braid – Woven material, usually metallic, used as shielding for wires and cables and as a ground.

Breakdown Voltage – The voltage at which the insulation between two conductors will break down.

Bunch Strand – Conductors twisted together with the same lay and direction without regard to geometric pattern.

C

Cable Filler – The material used in multi-conductor cables to occupy the interstices formed by the assembly of the insulated conductors, thus forming a cable of the desired shape.

Capacitance – The ability of a dielectric material between conductors to store electricity, when a difference of potential exists between the conductors. The unit of measurement is the farad which is the capacitance value which will permit one ampere of current, when the voltage across the capacitor changes at a rate of one volt per second.

Capacitive Coupling – Electrical interaction between two conductors caused by the capacitance between them.

Carrier – The basic woven element of a braid consisting of one or more ends (strands) which creates the interlaced effect.

Circuit – A complete path over which electrons flow from the negative terminals of a voltage source through parts and wires to the positive terminals of the same voltage.

Circular Mil – A unit of area equal to the area of a circle whose diameter is 1 mil (0.001 inch); equal to square mil X 0.78540. Used chiefly in specifying cross-sectional areas of round conductors.

Coaxial Cable – A cable consisting of two cylindrical conductors with a common axis. The two conductors are separated by a dielectric. The outer conductor, normally at ground potential, acts as a return path for current flowing through the center conductor and prevents energy radiation from the cable. The outer conductor, or shield is also commonly used to prevent external radiation from affecting the current flowing in the inner conductor. The outer shield or conductor consists of woven, or spiraled strands, or a metal foil sheath.

Concentric Stranding – A group of un-insulated wires twisted together and containing a center core with subsequent layers spirally wrapped around the core to form a single conductor.

Conductance – The reciprocal of resistance. It is the ratio of current passing through a material to the potential difference at its ends.

Conductivity – The ability of a material to allow electrons to flow, measured by the current per unit of voltage applied.

Conductor – A material suitable for carrying an electric current.

Contrahelical – The direction of a layer with respect to the previous layer spiraling in an opposite direction than the preceding layer within a wire or cable.

Core – In cables, a term used to express a component or assembly of components over which other materials are applied, such as additional components, shield or jacket.

Corona – A luminous discharge due to ionization of the gas surrounding a conductor around which exists a voltage gradient exceeding a certain critical value.

Coulomb – Unit quantity of electricity; i.e., the quantity transferred by one (1) ampere in one second.

Cross-Sectional Area of a Conductor – The sum of cross-sectional areas of its component wires, that of each wire being measured perpendicular to its individual axis.

Crosstalk – A type of interference caused by audio frequencies from one line being coupled into adjacent lines. The term is loosely used also to include coupling at higher frequencies.

Current – The rate of transfer of electricity. Practical unit is the ampere which represents the transfer of one coulomb per second.

Current Carrying Capacity – The maximum current a conductor can carry without heating beyond a safe limit.

Cycle – The complete sequence including reversal of the flow of an alternating current.

D

Db. – Abbreviation for decibel

Db. Loss – The loss of a signal in a conductor expressed in decibels.

D.C. – Abbreviation for direct current

Decibel – Unit expressing differences of power level. Used to express power gain in amplifiers or power loss in passive circuits or cables.

Denier – A term that describes the weight of a yarn (not cotton or spun rayon) which in turn determines its physical size.

Dielectric – 1) Any insulating medium which intervenes between two conductors and permits electrostatic attraction and repulsion to take place across it. 2) A material having the property that energy required to establish an electric field is recoverable in whole or in part, as electric energy.

Dielectric Absorption – The property of an imperfect dielectric whereby there is an accumulation of electric charges within the body of the material when it is placed in an electric field.

Dielectric Constant – Also called permittivity. That property of a dielectric which determines the amount of electrostatic energy that can be stored by the material when a given voltage is applied to it. Actually, the ratio of the capacitance of a capacitor using the dielectric to the capacitance of an identical capacitor using a vacuum as a dielectric.

Dielectric Loss – The time rate at which electric energy is transformed into heat in a dielectric when it is subjected to a changing electric field.

Dielectric Strength – The voltage which an insulating material can withstand before breakdown occurs, usually expressed as a voltage gradient (such as volts per mil).

Direct Current – An electric current which flows in only one direction.

Dissipation Factor – The tangent of the loss angle of the insulating material. The ration of the power loss to the circulating KVA.

Drain Wire – In a cable an un-insulated wire laid over the component or components and used as a ground connection.

Drawing – In the manufacture of wire, pulling the metal through a die or series of dies for reduction of diameter to a specified size.

Durometer – A measurement used to denote the hardness of a substance.

E

Eccentricity – A measure of the center of a conductor’s location with respect to the circular cross section of the insulation. Expressed as a percentage of center displacement of one circle within the other.

Electrostatic – Pertaining to static electricity, or electricity at rest. An electric charge, for example.

ETFE – A fluoropolymer insulating compound (Tefzel®)

Elongation – The fractional increase in length of a material stressed in tension.

ETP Copper – Electrolytic tough pitch copper 99.95% pure.

Extrusion – Method of forcing plastic, rubber, or elastomer material through an orifice in more-or-less continuous fashion to apply insulation or jacketing to a conductor or cable.

F

Farad – Unit of capacitance. The capacitance of a capacitor which, when charged with one coulomb, gives a difference of potential one volt.

Fatigue Resistance – Resistance to metal crystallization which leads to conductors or wires breaking from flexing.

F.E.P. – Abbreviation for fluorinated ethylene propylene.

Filler – Materials used in multi-conductor cables to occupy the interstices formed by the assembled conductors. Also, a substance, often inert, added to a plastic to improve properties and/or decrease cost.

Flat Braid – A woven braid which is rolled flat at the time of manufacture to a specific width depending upon construction.

Flex Life – The ability of a cable to bend many times before breaking.

Frequency – The number of times an alternating current repeats its cycle in one second.

G

Gauge – A term used to denote the physical size of a wire. Sometimes spelled gage.

Ground – An electrical term meaning to connect to the earth or other large conducting body to serve as an earth thus making a complete electrical circuit.

Ground Wire – A conductor leading from radio equipment to an electrical connection with the ground.

H

Hard Drawn Wire – Wire that has not been annealed after drawing.

Helical – Spiral

Helix – Spiral winding.

Henry – Unit of inductance when the induced electromotive force of one volt is produced by the inducing current changing at the rate of one ampere per second.

Hertz (Hz) – the unit of frequency, one cycle per second.

Hi-Pot Test – A test designed to determine the highest potential that can be applied to a conductor without breaking through the insulation.

High Voltage – Generally considered to be a wire or cable with an operating voltage of over 600 volts.

Hytrel® – Polyester insulating compound.

I

Impedance – The total opposition a circuit, cable, or component offers to alternating current. It includes both resistance and reactance and is generally expressed in ohms.

Impedance, Characteristic – In a transmission cable of infinite length, the ratio of the applied voltage to the resultant current at the point the voltage is applied. Or, the impedance which makes a transmission cable seem infinitely long, when connected across the cable’s output terminals. For a wavelength, it is the ratio of rms voltage to total rms longitudinal current at certain points in a diameter, when the wavelength is match-terminated.

Impedance Match – A condition whereby the impedance of a particular circuit cable or component is the same as the impedance of the circuit, cable, or device to which it is connected.

Inductance – A property of a conductor or circuit which resists a change in current. It causes current changes to lag behind voltage changes and is measured in henrys.

Insulation – Material having a high resistance to the flow of electrical current, to prevent leakage of current from a conductor.

Interstices – A minute space between one thing and another, especially between things closely set or between the parts of a body.

J

Jacket – Pertaining to wire and cable, the outer sheath which protects against environment and may also provide additional insulation.

K

Kilowatt – A unit of power equal to one thousand watts.

Kilovolt Ampere – 1000 volts X amperes.

Kilovolt – 1000 volts

L

Lay – Pertaining to wire and cable, the axial distance required for one cabled conductor or conductor strand to complete one revolution about the axis around which it is cabled.

Lay Direction – The twist in the cable as indicated by the top strands while looking along the axis of the cable away from the observer. Described as left hand or right hand.

Lead (pronounced “leed”) – A connecting wire, such as a test lead, or battery lead, or conductor brought out form a coil or winding.

Leakage – The undesirable passage of current over the surface of or through an insulator.

Litz Wire – Wire made from a number of fine individually insulated strands specifically cables or braided together to reduce skin effect and hence, lower resistance to high frequency currents for lower RF losses. Derived from the German word “litzendraht”

Loss – The portion of energy applied to a system that is dissipated and performs no useful work.

Low Noise Cable – Cable configuration specially constructed to eliminate spurious electrical disturbances caused by capacitance changes or self-generated noise induced by either physical abuse or adjacent circuitry.

M

Magnet Wire – Film insulated wire, commonly found in motors, transformers, and other coils for electromagnetic devices.

Megahertz – one million hertz.

MCM – Abbreviation for a thousand circular mils.

Melt Point – The point at which a material melts.

Mfd – Abbreviation for microfarad, one millionth of a farad.

Mhz – Abbreviation for Megahertz.

Micro – Prefix denoting one-millionth.

Mil – A unit of length equal to one thousandth of an inch.

Milli – Prefix meaning one-thousandth.

Multi-Conductor Cable – A combination of two or more conductors cabled together and insulated from one another.

N

Nanosecond – one thousandth of one millionth of a second.

NEC – Abbreviation for National Electrical Code.

NEMA – Abbreviation for National Electrical Manufactures Association.

O

OD – Abbreviation for outside diameter.

Ohm – the electrical unit of resistance. The value of resistance through which a potential difference of one volt will maintain a current of one ampere.

P

Periodicity – The uniformly spaced variations in the insulation diameter of a transmission cable that result in reflections of a signal, when its wavelength or multiple thereof equal to the distance between two diameter variations.

PFA – Abbrevation for Perflouroalkoxy.

Pf – Abbreviation for picofarad.

Picks Per Inch – The number of times the carriers in a braid cross over each other in the same direction along the longitudinal axis for each inch of length.

Pico – Prefix meaning one-millionth of one-millionth.

Picofarad – One-millionth of one-millionth of a farad. A micro-microfarad.

Plasticizer – A chemical added to plastics to make them softer and more flexible.

Plating – One method of applying a coating of metal over another metal.

Polymer – A substance made of many repeating chemical units or molecules. The term polymer is often used in place of plastic, rubber, or elastomer.

Propagation Delay – Time required for a signal to pass from the input to the output of a device.

PU – Abbreviation for polyurethane.

Pulse – A current or voltage which changes abruptly from one value to another and back to the original value in a finite length of time. Used to describe one particular variation in a series of wave motions.

PTFE – Abbreviation for polytetraflouroethylene.

PVC – Abbreviation for polyvinyl chloride.

R

Reactance – Opposition offered to the flow of alternating current by inductance or capacitance or a component or circuit.

Resistance – In D.C. circuits, the opposition a material offers to current, measured in ohms. In A.C. circuits, resistance is the real component of impedance, and may be higher than the value measured at D.C.

Rope Strand – A conductor composed of a center group of twisted strands surrounded by layers of twisted strands.

S

Separator – Pertaining to wire and cable, a layer of insulating material such as textile, paper or PTFE tape, which is placed between a conductor and its dielectric, between a cable jacket and the components it covers, or between various components of a multiple-conductor cable. It can be utilized to improve stripping qualities and/or flexibility, or can offer additional mechanical or electrical protection to the components it separates.

Shield – A sheet, screen, spiral or braid or metal, usually copper, aluminum, or other conducting material placed around or between electrical circuits or cables or components, to contain any unwanted radiation, or to keep out any unwanted interference.

Shield Effectiveness – the relative ability of a shield to screen out undesired radiation. Frequently confused with the term shield percentage.

Signal – A current used to convey information, either digital, analog, audio or video.

Skin Effect – The tendency of alternating current, as its frequency increases, to travel only on the surface of a conductor.

S.R. – Abbreviation for Silicone Rubber.

Standing Wave – The stationary pattern of waves produced by two waves of the same frequency travelling in opposite directions on the same transmission line. The existence of voltage and current maxima and minima along a transmission line is a result of reflected energy from an impedance mismatch.

Standing Wave Ratio (swr) – A ratio of the maximum amplitude to the minimum amplitude of a standing wave stated in current or voltage amplitudes.

Strand – one of the wires, or groups of wires, of any stranded conductor.

Surge – A temporary and relatively large increase in the voltage or current in an electric circuit or cable. Also called transient.

Sweep-test – A test given to check attenuation by oscilloscope, as in coaxial cable.

T

Tear Strength – Force required to initiate or continue a tear in a material under specified conditions.

Tensile Strength – The pulling stress required to break a given specimen.

Temperature Rating – the maximum temperature at which the insulating material may be used in continuous operation without loss of its basic properties.

Thermocouple – A device for measuring temperature where two electrical conductors of dissimilar metals are joined at the point of heat application and a resulting voltage difference, directly proportional to the temperature, is developed across the free ends and is measured potentio-metrically.

Thermoplastic – A material which will soften, flow, or distort appreciably when subjected to sufficient heat and pressure. Examples are polyvinyl chloride and polyethylene.

Thermosetting – A material which will soften, flow or distort appreciably when subjected to heat and pressure. Examples are rubber and neoprene.

Tinned Wire – Wire that is coated with a thin layer of tin to simplify soldering.

Tinsel Wire – A type of electrical conductor comprised of a number of tiny threads, each thread having a fine, flat, ribbon of copper or other metal closely spiraled about it. Used for small size cables requiring limpness and extra-long flex life.

Tolerance – A specified allowance for error from a standard or given dimension, weight, or property.

Triaxial – Refers to a three conductor cable with one conductor in the center, a second circular conductor shield concentric with the first, and third circular conductor shield insulated from and concentric with the first and second, usually with insulation, and a braid overall.

Transfer impedance

Twisted Pair – A cable composed of two small insulated conductors, twisted together without a common covering. (Note: The two conductors of a twisted pair are usually substantially insulated, so that the combination is a special case of a cord.)

U

U.L – Abbreviation for Underwriters Laboritories.

Unbalanced Line – A transmission line in which voltages on the two conductors are unequal with respect to ground, e.g. a coaxial cable.

Unilay – More than one layer of helically laid wires with the direction of lay and length of lay the same for all layers.

V

Velocity of Propagation – The transmission speed of an electrical signal down a length of cable compared to speed in free space. Usually expressed as a percentage.

Volt – A unit of electrical pressure. One volt is the amount of pressure that will cause one ampere of current in one ohm of resistance.

Voltage – Electrical potential or electromotive force expressed in volts.

Voltage Rating – The highest voltage that may be continuously applied to a wire in conformance with standards or specifications.

W

Watt – A unit of electrical power. One watt is equivalent to the power represented by one ampere of current under a pressure of one volt in a D.C. circuit.

Wave Length – The distance between the nodes of a wave. The ratio of the velocity of the wave to the frequency of the wave.

Wire gauge – A system of numerical designations of wire sizes.

Y

Yield Strength – The lowest stress at which a material undergoes plastic deformation. Below this stress, the material is elastic, above, viscous.