A

A - a symbol designation for ampere.

ABR - Available Bit Rate.

Abrasion Resistance - Ability of a wire, cable or material to resist surface wear.

Abrasion Stripper - More accurately described as "buffing stripper", which is a motorized device for removing flat cable insulation by means of one or two buffing wheels that melt the insulation and brush it away from the conductors.

AC - Alternating current.

Accelerated Aging - A test that simulates long time environmental conditions in a relatively short time.

ACR - The difference between attenuation and crosstalk, measured in dB, at a given frequency (acronym for Attenuation Crosstalk Ratio). Important characteristic in networking transmission to assure that signal sent down a twisted pair is stronger at the receiving end of the cable than are any interference signals imposed on that same pair by crosstalk from other pairs.

Ace Wire and Cable Co., Inc. - Master stocking distributor of wire, cable and connectivity products for: voice, data, video, power, building wire, security, and fire alarm.

ADSL - Asymmetric Digital Subscriber Line

AF - Audio frequency.

Air Core -Cables that are not gel filled.

Air-Gap Dielectric - A coaxial design in which a monofilament of plastic holds the center conductor in place allowing the remainder of the dielectric to be air. Typical velocities of up to 84% can be achieved in this design.

Alloy - A combination of two or more different polymers/metals. Usually combined to make use of different properties of each polymer metal.

Alpeth - Coated Aluminum Polyethylene. Basic sheath.

Alternating Current (AC) - Electric Current that alternates or reverses polarity continuously. The number of alternations per second are described as cycles, (hertz or Hz).

AM - Amplitude modulation.

Ambient - Conditions existing at a test or operating location prior to energizing equipment (e.g.: ambient temperature).

American Wire Gauge (AWG) - A standard for expressing wire diameter. As the AWG number gets smaller, the wire diameter gets larger.

Ampacity - Current handling capability. The maximum current a conductor can carry without being heated beyond a safe limit.

Ampere - A standard unit of current. Defined as the amount of current that flows 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.

Amplitude - The Maximum value of a varying wave form.

Analog - Representation of data by continuously variable quantities.

Analog Signal - An electrical signal which varies continuously, not having discrete values. Analog signals are copies or representations of other waves in nature. An analog audio signal, for instance, is a representation of the pressure waves which make up audible sound.

Anneal - To soften and relieve strains in any solid material, such as metal or glass, by heating to just below its melting point and then slowly cooling it. Annealing generally lowers the tensile strength of the material, while improving its flex life and flexibility.

ANSI - American National Standards Institute.

ASP - Aluminum Steel Polyethylene. Provides mechanical and electrical protection.

ASTM - The American Society for Testing and Materials, a standards organization which suggests test methods, definitions and practices.

Asynchronous Transfer Mode - The SONET standard for a packet switching technique which uses packets of a fixed length.

ATM - The SONET standard for a packet switching technique which uses packets of a fixed length. Asynchronous Transfer Mode.

Attenuation - The decrease in magnitude of a signal as it travels through any transmitting medium, such as a cable or circuitry. Attenuation is measured as the logarithm of a ratio. It is expressed in decibels or dB.

Audio - A term used to describe sounds within the range of human hearing. Also used to describe devices which are designed to operate within this range (20 Hz to 20 kHz).

Audio Frequency - Frequencies within the range of human hearing: approximately 20 to 20,000 Hz.

AWG - American Wire Gage. A wire diameter specification. The smaller the AWG number, the larger the wire diameter.

AWM - Appliance Wiring Material.

B

Backbone - The cable used to connect all systems of a multi-level distributed system to an intermediate system.

Backshell - Metal housing providing continuity of shield through IDC connectors.

Balanced Line - A cable having two identical conductors which carry voltages opposite in polarity and equal in magnitude with respect to ground, suitable for differential signal transmission.

Balun - A device for matching an unbalanced coaxial transmission line to a balanced two-wire system. Can also
provide impedance transformation, as 300 ohm balanced to 75 ohm unbalanced.

Bandwidth - The difference between the upper and lower limits of a given band of frequencies. Expressed in Hertz. The range of frequencies that a transmitted communications signal occupies or that a receiving system can accept. For example, it takes more bandwidth to download a photograph in a second than to download a page of text. Virtual reality and three-dimensional audio/visual presentations require even more.

Baud - Unit of data transmission speed meaning bits per second (500 baud=500 bits per second).

Bel - A unit that represents the logarithm of the ratio of two levels. The number of bels is equal to the logarithm sub 10 of P sub 1/P sub 2):2 logarithm sub 10 (E sub 1/E sub 2); and 2 logarithm sub 10 (I sub 1/I sub 2). See dB.

Bend Loss - A form of increased attenuation caused by (a) having an optical fiber curved around a restrictive radius of curvature or (b) microbends caused by minute distortions in the fiber imposed by externally induced perturbations.

Bend Radius - Radius of curvature that a flat, round, fiber optic or metallic cable can bend without any adverse effects.

Binder - A tape or thread used for holding assembled cable components in place.

Bit - One binary digit.

Bit Error Rate - The number of errors occurring in a system per second. Typically less than 10e-12.

Bits Per Second - The number of binary bits that can be transmitted per second - I.e. Mbps (Mega - millions), Gbps (Giga - billions).

BNC - Abbreviation for "Bayonet Neil Concelman". A coaxial cable connector used extensively in video and R. F. applications and named for its inventor.

Bonded Steel is bonded to polyethylene with a copolymer adhesive All STALPETH and some ASP cables are bonded. Provides extra strength to jacket, primarily used in underground applications.

Bonded ASP - Aluminum Steel Polyethylene where the steel is bonded to polyethylene for strength. Filled cables for use in ducts.

Bonding - The method used to produce good electrical contact between metallic parts of any device. Used extensively in automobiles and aircraft to prevent static buildup. Also refers to the connectors and straps used to bond equipment.

Booster - A device or amplifier inserted into a line or cable to increase the voltage. Transformers may be employed to boost ac voltages. The term booster is also applied to antenna preamplifiers.

BPS - The number of binary bits that can be transmitted per second - I.e. Mbps (Mega - millions), Gbps (Giga - billions).

BPSK Bi - Phase Shift Keying.

Braid - A group of textile or metallic filaments interwoven to form a tubular flexible structure which may be applied over one or more wires, or flattened to form a strap.

Braid Angle - The angle between a strand of wire in a braid shield and the axis of the cable it is wound around.

Breakdown Voltage - The voltage at which the insulation between two conductors will fail and allow electricity to conduct or 'arc'.

Breakout - The point at which a conductor or conductors are separated from a multi-conductor cable to complete circuits at various points along the main cable.

BRI - Basic Rate Interface ISDN.

Broadband - The technique used to multiplex multiple networks on a single cable without interfering with each other. Technologies that allow you to transmit or receive higher volumes of data at higher speeds.

Buffer - A protective coating over an optical fiber.

Buffing Stripper - A motorized device for removing flat cable insulation by means of one or two buffing wheels that melt the insulation and brush it away from the conductors. Also called Abrasion Stripper.

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

Buried Cables that are required to go underground.

Bus-bar Wire - Uninsulated tinned copper wire used as a common lead.

Butyl Rubber - A synthetic rubber with good electrical insulating properties.

Byte - A group of adjacent binary digits (8 bits).

C

Cable - A group of individually insulated conductors twisted helically.

Cable Modem - A device that enables you to hook up your PC to a local cable TV line and receive data at much faster rates than telephone modems and ISDN lines. A strong competitor to DSL telephone service.

Cabling - The grouping or twisting together of two or more insulated conductors to form a cable.

CACSP - Coated Aluminum, Coated Steel, Polyethylene. Provides additional strength and protection.

Canadian Electrical Code (CEC) - Canadian version of the US National Electrical Code (NEC).

CAP - Carrierless Amplitude Phase Modulation.

Capacitance - The ability of a dielectric material between conductors to store energy when a difference of potential exists between the conductors. The unit of measurement is the farad. Cable capacitance is usually measured in picofarads (pF).

Capacitive Crosstalk - Cable crosstalk or interference resulting from the coupling of the electrostatic field of one conductor upon one or more others.

Capacitive Reactance - The opposition to alternating current due to the capacitance of a capacitor, cable, or circuit. It is measured in ohms and is equal to 1/6.28fC where f is the frequency in Hz and C is the capacitance in farads.

Capacitor - Two conducting surfaces separated by a dielectric material. The capacitance is determined by the area of the surfaces, type of dielectric, and spacing between the conducting surfaces.

Carrier Strip - Also referred to as substrate. A film that is on one side of a laminated flat cable.

CASPIC - Coated Aluminum, Coated Steel.

Category - Rating of a cable established by TIA/EIA to indicate the level of electrical performance.

Category Cables Belden manufactures Category 3 to 7 cables, all high performance twisted pair data cables. The higher the category number, the greater the bandwidth. Category 7 is currently the highest performance telecommunication wire available. Ours is certified to applicable UL standards.

CATV - Abbreviation for Community Antenna Television. Cable TV.

CB - Citizens band.

CBR - Constant Bit Rate.

CCTV - Closed-circuit television.

Center-to-Center Distance - Pitch. Nominal distance from center-to-center of adjacent conductors within a cable. When conductors are flat, pitch is usually measured from the reference edge of a conductor to the reference edge of the adjacent conductor.

Channel - The horizontal cable including the workstation outlet and patch panel in the telecommunications closet plus a maximum combined length of up to ten meters of patch cable at each end (maximum length of 100 meters).

Characteristic Impedance - 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.

Chrominance Signal - The portion of a composite video signal that contains the color information.

Circuit - A system of conducting media designed to pass an electric current.

Circular Mil - The area of a circle one one-thousandth of an inch (.001") in diameter. By knowing the circular mil area of various conductors, they can be used to determine what conductivity and gage size various combinations will produce.

Cladding - A low refractive index material that surrounds the core of an optical fiber causing the transmitted light to travel down the core and protects against surface contaminant scattering. A layer of metal applied over another. Cladding is often chosen to improve conductivity or to resist corrosion.

CO - Central Office.

Coaxial Cable - A cylindrical transmission line comprised of a conductor centered inside a metallic tube or shield, separated by a dielectric material, and usually covered by an insulating jacket. The kind of cable that links your cable TV provider to your home or office. Also sometimes used by telephone companies from their telephone poles to their customers, and by businesses for local area networks. Because of its high bandwidth, you can simultaneously receive hundreds of channels from coaxial cable.

Coil Effect - The inductive effect exhibited by a spiral-wrapped shield, especially above audio frequencies.

Color Code - A system of different colors or stripes used to identify components of cables such as individual conductors or groups of conductors.

Component Video - The unencoded output of a camera, video tape recorder, etc., whereby each red, green, and blue signal is transmitted down a separate cable. Component video systems most commonly use bundled coax as a transmission medium.

Composite Cable - Cable having conductors with two or more AWG sizes or more than one cable type.

Composite Video - The encoded output of a camera, video tape recorder, etc., whereby the red, green, blue, horizontal and vertical sync are transmitted simultaneously down one cable.

Concentric Stranding - A group of uninsulated wires twisted together and containing a center core with subsequent layers spirally wrapped around the core with alternating lay directions to form a single conductor.

Conductivity - The ability of a material to allow electrons to flow, measured by the current per unit of voltage applied. It is the reciprocal of resistivity.

Conductor - A substance, usually metal, used to transfer electrical energy from point to point.

Conduit - A tube of metal or plastic through which wire or cable can be run. Used to protect the wire or cable and, in the case of metal conduit, make it fireproof.

Connector - A device designed to allow electrical flow from one wire or cable to a device on another cable. A connector will allow interruption of the circuit or the transfer to another circuit without any cutting of wire or cable or other preparation.

Copperweld - Trademark of Copperweld Steel Co. for copper-clad steel conductor.

Cord - A very flexible insulated cable.

Core - The light conducting central portion of an optical fiber with a refractive index higher than that of the cladding. The center of a cable construction. Most often applies to a coaxial cable, where the core is the center conductor and the dielectric material applied to it.

Coupling - The transfer of energy (without direct electrical contact) between two or more cables or components of a circuit.

Coverage - How well a metal shield covers the underlying surface. Measured in percent.

CPE - Chlorinated polyethylene can be used as either a thermoplastic or thermoset. It is a tough chemical and oil-resistant material and makes an excellent jacket for industrial control cable. As a thermoset, it can be used as an oil resistant cord jacket. Other outstanding properties include low water absorption and superior crush resistance, which are important attributes in industrial control applications.

CPS - Abbreviation for cycles per second or Hertz.

CPU - Central Processing Unit.

Crosstalk - A type of interference caused by audio frequencies from one pair being coupled into adjacent pairs.
The term is also used to describe coupling at higher frequencies.

CRT - Cathode Ray Tube.

CSA - Abbreviation for Canadian Standards Association, the Canadian version of the Underwriters Laboratories.

CSMA/D - Carrier Sense Multiple Access/Collision Detection.

Current Carrying Capacity - The maximum current a conductor can carry without being heated beyond a safe limit (ampacity).

Current Loop - A two wire transmit/receive interface.

Current, Alternating (ac) - An electric current that periodically reverses direction of electron flow. The rate at which a full cycle occurs in a given unit of time (generally a second) is called the frequency of the current.

Current, Direct (dc) - Electrical current whose electrons flow in one direction only. It maybe constant or pulsating as long as its movement is in the same direction.

Cut-through Resistance - A test to determine the ability of a material to withstand the application of blades or sharp edges without being cut.

D

D1 - A component digital video recording format that conforms to the CCIR-601 standard. Records on 19 mm magnetic tape. (Often used incorrectly to indicate component digital video).

D2 - A composite digital video recording format. Records on 19 mm magnetic tape.

D3 - A composite digital video recording format. Records on 1/2" magnetic tape.

Daisy Chain - A cable assembly with three or more termination areas.

DB - See Decibel.

DBS - Direct Broadcast Satellite.

DC - Direct current.

Decibel (dB) - A decibel is one-tenth of a bel and is equal to 10 times the logarithm of the power ratio, 20 times the log of the voltage ratio, or 20 times the log of the current ratio. Decibels are also used to express acoustic power, such as the apparent level of a sound. The decibel can express an actual level only when comparing with some definite reference level that is assumed to be zero dB.

Delay Line - A transmission line or equivalent device designed to delay a wave or signal for a specific length of time.

DEPIC - Dual Expanded Plastic Insulated Conductor (Foam Skin). Decreases outside diameter of cable.

Derating Factor - A multiplier used to reduce the current carrying capacity of conductors in more adverse environments.

DES - Data Encryption Standard.

DHCP - Dynamic Host Configuration Protocol.

Dielectric - An insulating (non-conducting) medium when used in a signal-carrying design.

Dielectric Breakdown - Any change in the properties of a dielectric that causes it to become conductive. Normally a catastrophic failure of an insulation because of excessive voltage.

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 (which has a Dielectric Constant of 1) as a dielectric. A number which indicates the quality of a material to resist holding an electrical charge when placed between two conductors.

Dielectric Heating - The heating of an insulating material when placed in a radio-frequency field, caused by internal losses during the rapid polarization reversal of molecules in the material.

Dielectric Loss - The power dissipated in a dielectric as the result of the friction produced by molecular motion when an alternating electric field is applied.

Dielectric Strength - The voltage an insulation can withstand before it breaks down. Usually expressed as 'volts per mil'.

Dielectric Withstand Voltage - The voltage that an insulating material can withstand before breakdown occurs.

Digital Signal - An electrical signal which possesses two distinct states (on/off, positive/negative).

Dispersion - The cause of bandwidth limitations in an optical fiber. Dispersion causes a broadening of input pulses along the length of the fiber. Two major types are (a) mode dispersion caused by differential optical path lengths in a multimode fiber, and (b) material dispersion caused by a differential delay of various wavelengths of light in a wave guide material.

Distortion - Any undesired change in a wave form or signal.

Distribution Cables - In a CATV system, the transmission cable between the distribution amplifier and the drop cable.

Disturbed Conductor - A conductor that receives energy generated by the field of another conductor or an external source. e.g. the quiet line.

DMT - Discrete Multitone.

DOCSIS - Data Over Cable Service Interface Specification.

Drain Wire - A non-insulated wire in contact with parts of a cable, usually the shield, and used in the termination to that shield and as a ground connection.

Drop Cable - In a CATV system, the transmission cable from the distribution cable to a dwelling.

DSL - Digital Subscriber Line. A technology for bringing high-bandwidth information to homes and small businesses over ordinary copper telephone lines. A DSL line can carry both data and voice signals, with the data part of the line remaining continuously connected. Currently competes with the cable modem in bringing broadband services to homes and small businesses.

DVB - Digital Video Broadcast.

 

E

E - Voltage (electromotive force).

EFP - Abbreviation for Electronic Field Production. Video production for commercials, television shows and other non-news purposes done outside the studio.

EIA - Electronic Industries Association (formerly RMA or RETMA).

Elastomer - Any material that will return to its original dimensions after being stretched or distorted.

Electromagnetic - Referring to the combined electric and magnetic fields caused by electron motion through conductors.

Electromagnetic Coupling - The transfer of energy by means of a varying magnetic field. Inductive coupling.

Electron Volt - A measure of the energy gained by an electron falling through an electric field produced by one volt.

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

Electrostatic Coupling - The transfer of energy by means of a varying electrostatic field. Capacitive coupling.

ELFEXT - Equal level Far End Crosstalk (dB) - A subtraction of attenuation from FEXT. By subtracting the attenuation, ELFEXT negates the effects of attenuation on the interference as it propagates down the cable, thus bringing it to an "equal level".

Elongation - The increase in length of a wire or cable cause by longitudinal tension.

EMF - Electromotive force (voltage).

EMI - Abbreviation for electromagnetic interference.

Energy - The capability of doing work.

Energy Dissipation - Loss of energy from a system due to the conversion of work energy into an undesirable form usually heat. Dissipation of electrical energy occurs when current flows through a resistance.

ENG - Abbreviation for Electronic News Gathering.

EPDM - Ethylene-propylene-diene monomer rubber. A chemically cross-linked elastomer with good electrical insulating properties and excellent flexibility at high and low temperatures. It has good insulation resistance and dielectric strength, as well as excellent abrasion resistance and mechanical properties. EPDM has better cut-through resistance than Silicone rubber, which it replaces in some applications.

EPR - Ethylene-propylene copolymer rubber. A material with good electrical insulating properties.

Equilay - More than one layer of helically laid wires with the length of the lay the same for each layer.

ETP - Abbreviation for a copper refining process called Electrolytic Tough Pitch. This process produces a conductor that is 99.95% pure copper resulting in high conductivity.

EV - Electron volt.

Expanded Polyethylene - Expanded or "foam" polyethylene, consists of individual closed cells of inert gas suspended in a polyethylene medium, resulting in a desirable reduction of the dielectric constant.

Extruded Cable - Conductors are simultaneously insulated and the cable is formed by a continuous extrusion process.

F

f - Frequency.

FAS - Fire Alarm and Signal Cable, CSA (Canadian Standards Association) Cable Designation.

FCFC - Abbreviation for flat conductor flat cable.

FDDI - Fiber Data Distribution Interface.

FEC - Forward Error Correction.

Feedback - Energy that is extracted from a high-level point in a circuit and applied to a lower level. Positive feedback reduces the stability of a device and is used to increase the sensitivity or produce oscillation in a system. Negative feedback, also called inverse feedback, increases the stability of a system as the feedback improves stability and fidelity.

Feeder Cable - In a CATV system, the transmission cable from the head end (signal pickup) to the trunk amplifier. Also called a trunk cable.

FEP - Fluorinated ethylene-propylene. A thermo-plastic material with good electrical insulating properties and chemical and heat resistance.

Ferrous - Composed of and/or containing iron. A ferrous metal exhibits magnetic characteristics.

FEXT - Far End Crosstalk (dB) - Crosstalk induced on the pairs, measured at the "far" end of the cable.

Fiber - A single, separate optical transmission element characterized by core and cladding.

Fiber Optics - Light transmission through optical fibers for communication and signaling. A technology that transmits information as light pulses along a glass or plastic fiber. Optical fiber carries much more information than conventional copper wire and is generally not subject to interference. Most telephone company long-distance lines are optical fiber.

Fiber to the home (FTTH) - A technology that provides voice, data and video services from the phone company's branch office to local customers over an all-fiber optic link. Still in its infancy, FTTH technology is substantially more expensive and labor-intensive to install and maintain than competing technologies.

Field - An area through which electric and/or magnetic lines of force pass.

Filled - Cables that are gel filled.

Fillers - Nonconducting components cabled with the insulated conductors or optical fibers to impart roundness, flexibility, tensile strength, or a combination of all three, to the cable.

Flame Resistance - The ability of a material not to fuel a flame once the source of heat is removed.

Flat Cable - Also referred to as planar and/or ribbon cable. Any cable with two or more parallel conductors in the same plane encapsulated by insulating material.

Flat Conductor - A conductor with a width-to-thickness ratio or arbitrarily 5 to 1 or greater.

Flat Conductor Cable - A flat cable with a plurality of flat conductors.

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

Flexibility - The ability of a cable to bend in a short radius. The ability of a cable to lay flat or conform to a surface as with microphone cables.
Floating - Referring to a circuit which has no connection to ground.

Fluorocopolymer - Generic term for PVDF.

FM - Frequency modulation.

Foam Polyethylene - Expanded or "foam" polyethylene, consists of individual closed cells of inert gas suspended in a polyethylene medium, resulting in a desirable reduction of the dielectric constant.

FR-TPE - FR-TPE, flame retarded thermoplastic elastomer, is a rubber-like plastic that has properties similar to rubber yet is processed as a thermoplastic. It is used as the insulation and jacket in an all TPE construction which meets UL 13 and 1277 industrial cable requirements. It has good electrical properties, abrasion resistance, colorability and flame retardancy. This compound is ideal for cold weather applications.

FREP - Flame retardant ethylene propylene is a special flame retardant version of EPDM rubber. It is designed for use as an industrial control insulation and has excellent electrical, deformation resistance, and also meets the flame retardant needs of industrial control cables.

Frequency - The number of times a periodic action occurs in one second. Measured in Hertz.

Frequency Response - The characteristic of a device denoting the range of frequencies over which it may be used effectively.

Frequency, Power - Normally, the 50 or 60 hertz power available in residential areas.

FSK - Frequency Shift Key.

FTTC - Fiber-to-the-Curb.

G

Gage - The physical diameter of a wire. A standard for expressing wire diameter. As the AWG number gets smaller, the wire diameter gets larger.

Gain - The increase of voltage, current, or power over a standard or previous reading. Usually expressed in decibels.

Giga - One billion.

Gigahertz (GHz) - A unit of frequency equal to one billion hertz.

Ground - An electrical connection between a circuit and the earth. Also refers to a conductor connected to earth. In some instances, can refer to a central metallic point designated as having "zero" potential.

Ground Conductor - A conductor in a transmission cable or line that is grounded.

Ground Loop - A completed circuit between shielded pairs of a multiple pair created by random contact between shields. An undesirable circuit condition in which interference is created by ground currents when grounds are connected at more than one point.

Ground Potential - The potential of the earth. A circuit, terminal, or chassis is said to be at ground potential when it is used as a reference point for other potentials in the system.

H

Harness - A flat cable or group of cables, usually with many breakouts with the wire ends prepared for termination or terminated to connectors and ready to install.

HDSL - High bit-rate Digital Subscriber Line.

Headroom - The amount by which a cable ACR exceeds 10 dB. The TIA/EIA 568B standard states a minimum of 10 dB of ACR is required for Category 5 certification.

Hertz (Hz) - The number of changes in polarity which a signal makes in one second. An indication of frequency. Replaces cycles-per-second.

Heterogeneous Insulation - A cable insulating system composed of two or more layers of different insulating materials.

HF - High frequency.

HFC - Hybrid Fiber/Coaxial.

High Frequency - The band from 3 to 30 MHz in the radio spectrum, as designated by the Federal Communications Commission.

Homogeneous Insulation - A complete cable insulation structure whose components cannot be identified as layers of different materials.

Hook-Up Wire - Single conductor wire with various types of insulation.

Horizontal Cable - Cable used to go between the workstation outlet and the telecommunications closet.

HSCDS - High-Speed Cable Data Service.

p>[^>]* - Hypertext Markup Language.

HTTP - Hypertext Transmission Protocol.


I

p>[^>]* -Symbol used to designate current.

I/O Interconnection - Input/Output interface to the "outside world."

IDSL - ISDN Digital Subscriber Line.

IEEE - Institute of Electrical and Electronic Engineers.

IF - Intermediate-frequency.

IFB - Abbreviation for Interrupted Feed Back, a monitoring scheme often used in television where the feed of program audio can be interrupted with directions, cues or other information.

Input - A signal (or power) which is applied to a piece of electric apparatus or the terminals on the apparatus to which a signal or power is applied.

Insertion Loss - A measure of the attenuation of a cable or component by determining the output of a system before and after the device is inserted into the system.

Insulation - A material having good dielectric properties which is used to separate close electrical components, such as cable conductors and circuit components.

Insulation Stress - The molecule separation pressure caused by a potential difference across an insulator. The practical stress on insulation is expressed in volts per mil.

Interface - The region where two systems or a major and a minor system meet and interact with each other.

Interference - Disturbances of an electrical or electromagnetic nature that introduce undesirable responses into other electronic equipment.

Intermediate Frequency - A frequency to which a signal is converted for ease of handling. Receives its name from the fact that it is an intermediate step between the initial and final conversion or detection stages.

IR - Insulation Resistance.

IR Drop - The designation of a voltage drop in terms of current and resistance.

ISDN - Integrated Services Digital Network. An alternative to telephone modems that allows digital transmission over ordinary telephone copper wire and other media. Home and business users can get highly graphic Web pages more quickly through ISDN adapters than through dial-up connections.

ISO - International Standards Organization.

Isolation - The ability of a circuit or component to reject interference, usually expressed in dB.

ISP - Internet Service Provider.


J

Jacket - Pertaining to wire and cable, the outer protective covering (may also provide additional insulation).

Jumper - A short length of conductor or flat cable used to make a connection between terminals or around a break in a circuit, or between circuit boards.

K

KB - Kilobyte.

KEV - 1000 electron volts.

Kilo - One thousand.

kV - Kilovolt (1000 volts).

kVA - Kilovolt ampere.

kW - Kilowatt.



 

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