Facsimile
The remote reproduction of graphic material; an exact copy

Farad
A unit of capacitance when a difference of potential of 1 volt produces a displacement of one coulomb in a capacitor. The farad is a very large unit and a much smaller unit, the microfarad (µf), is more commonly used

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

Fault, Ground
A fault to the ground

FCC
Federal Communications Commission

FDDI (Fiber Distributed Data Interface)
An ANSI defined token-passing ring using fiber optic media to attain a 100mbps transmission rate

FDX
Full Duplex. Transmission in two directions simultaneously, or, more technically, bidirectional simultaneous two-way communications

FEP
Fluorinated ethylene propylene. Teflon is DuPont's trademark for this material

FEPB
A UL cable type. Fluorinated ethylene propylene insulated wire with glass braid

FFH-2
A UL type of fixture wire with a 600V rating

Fiber Dispersion
Pulse spreading in an optical fiber caused by differing transit times of various modes

Fiber Optics
Transmission of energy by light through glass fibers. A technology that uses light as an information carrier. Fiber optic cables (light guides) are a direct replacement for conventional cable and wire pairs. The glass-based transmission cable occupies far less physical volume for an equivalent transmission capacity; the fibers are immune to electrical interference

Fiber Tubing
A loose, crush-resistant, cylinder applied over individual fibers to provide mechanical protection. Also called a buffer tube

Field Coil
A suitable insulated winding mounted on a field pole to magnetize it

Field Molded Splice
A joint in which the solid dielectric joint insulation is fused and cured thermally at the job site

Field Tests
Tests which may be made

Figue 8 Cable
An aerial cable configuration in which the caonductors and the steel strand which supports the cable are integrally jacketed. A cross section of the finished cable approximates the figure "eight"

Filled Cable
A cable construction in which the cable core is filled with a material that will prevent moisture from entering or passing through the cable

Filler
Fillers are used in multiconductor cables which occupy the interstices formed by the assembled conductors . This is done so that the finished cable will be round

Filling Compound
A dielectric material poured or injected into a splice housing or cable to prevent the entry of water. Filling compounds may rewuire heating or mixing prior to filling. Some filling compounds may also serve as the insulation

Film
A thin plastic sheet

Fine Stranded Wire
Stranded wire with component strands of 36 AWG or smaller

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

Flammability
The measure of a material's ability to support combustion

Flashover
A disruptive discharge around or over the surface of a solid or liquid insulator

Flat Braid
A woven braid of tinned copper strands rolled flat at the time of manufacture to a specified width

Flat Cable
A cable with two essentially flat surfaces

Flat Conductor
A wire having a rectangular cross section as opposed to a round or square conductor

Flex-Life
The measurement of the ability of a conductor or cable to withstand repeated bending

Flexibility
The ease with which a cable may be bent

Flexible
That quality of a cable or cable component which allows for bending under the influence of an outside force, as opposed to limpness which is bending due to the cable's own weight

Floating
Refers to a circuit which has no electrical connection to the ground

Fluoropolymer
A class of polymers used as insulating and jacketing materials. Common ones include Teflon, Tefzel, Kynar and Halar

Flux
(1) The lines of force which make up an electrostatic field
(2) The rate of flow of energy across or through a surface
(3) A substance used to promote or facilitate fusion

FM (Frequency Modulation)
A modulation technique in which the carrier frequency is shifted by an amount proportional to the value of the modulating signal. The deviation of the carrier frequency determines the signal content of the message

Foamed Insulation
Insulations having a cellular structure

Foil
A thin, continuous sheet of metal

Frequency
The number of cycles per second at which an analog signal occurs, expressed in Hertz (Hz). One Hertz is one cycle per second

Frequency Analyzer
An instrument to measure the intensity of various component frequencies from a transmitting source

Frequency Counter
An electronic measuring instrument that counts the number of cycles of a periodic electrical signal during a given time interval

Frequency Modulation (FM)
Method of encoding a carrier wave by varying the frequency of the transmitted signal

Frequency Plan
Specification of how the various frequencies of a broadband cable system are allocated for use

"F" Type Connector
A low cost connector used by the TV industry to connect coaxial cable to equipment

Full Duplex
Two-way communications in which each modem simultaneously sends and receives data at the same rate

Fuse Wire
Wire made from an alloy that melts at a relatively low temperature

Fused Coating
A metallic coating which has been melted and solidified, forming a metallurgical bond to the base material

Fused Conductors
Individual strands of heavily tinned copper wire stranded together and then bonded together by induction heating

Fused Spiral Tape
A PTFE insulation often used on hookup wire. The spiral wrapped tape is passed through a sintering oven where the overlaps are fused together