AC Generator: An AC power source, such as a machine that uses magnetism and mechanical force to produce an AC current
AC Transformer: A cubically shaped plugged device that when inserted into an AC outlet steps down the voltage to a level usable by the amplifier
Adjacent channels: Channels above or below the reference channel
Alternators: A generator that produces alternating current
Ammeter: An instrument used to measure current flow
Ampere (A): The basic unit of measurement of electron current. It indicates the rate of flow of current or electrons. The amount of 1 volt across 1 ohm of resistance results in 1 ampere of current. The current of 1 ampere is produced when 1 coulomb (6.28 x 1018 electrons) passes a given point in 1 second.
Ampere-turns: The unit of measurement of the mmf in a coil of wire. The ampere-turns value is determined by multiplying the electric current (in amperes) flowing through the coil by the number of turns in the coil.
Amplitude: The size or magnitude of an RF carrier; i.e. the strength of the signal.
Analog display: Method of showing signal strength and battery condition measured by an SLM using a continuously variable indicating needle in front of a calibrated scale
Analog: A type of transmission method using continuously varying signals to convey information
Analog terminal adapter (ATA): An analog terminal adapter connects an analog telephone to a VOIP network using an Ethernet jack and an RJ11 phone jack
Angular velocity: The rate of change of angular or rotational motion, measured in degrees per second or radians per second
Armature: Metal loops of wire in which current is induced in an AC generator
Atom: The basic building block of matter composed of different types of particles. Major atom particles are the electron; proton; neutron
Attenuated: A reduced signal level strength (power) caused by transmission through a system/network, cable or device, expressed in dB
Attenuation: An effect that results in a reduction in amplitude only of an electrical signal
Average value: The maximum level of the positive or negative half cycle of an AC waveform
Axiom: A self-evident or universally accepted truth
B voltage detector: A handheld safety device that detects the presence of hazardous AC or DC voltage potential near or on metal
Band pass filter: A filter that blocks or removes the signals of all the frequencies on either side of a desired frequency or frequencies
Band stop filter: A filter that passes most frequencies while selectively blocking or removing a small portion of the bandwidth
Bands: Groupings of contiguous RF frequencies that are named and have specific channels assigned to them. For example, the "low-band" ranges form 54 Mhz to 88 Mhz and contain TV channels 2-6
Barker channels: A channel that is pre-selected by the cable company for some addressable set-top terminals to automatically tune to when there is a loss of data carrier, non-payment of bill, or when a customer attempts to tune to a channel that is not included in the level of service
Baseband: Group of frequencies occupied by the "raw" video or the "raw" audio signals not modulated onto the RF carrier of any channel
Bels: Units of measurement of electrical power equal to a ratio of 10:1
Bending radius: The radius of an imaginary circle described by the inside edge of a bend in the cable
Bidirectionally: Description of a flow in two or both directions, such as AC conducting in both upstream and downstream directions from the power inserter
Binary phase shift keying (BPSK): A digital modulation scheme in which the phase of an RF carrier is shifted between two states to respectively represent the 1s or 0s of a data transmission
Bit Rate: The number of binary digits, 1s and 0s, that are transported through the system in a second
Blind hoppinge: A type of frequency shifting in which the transmitter is making the move to a new frequency on a random and uninformed basis
Breakdown voltage: The amount of voltage required to break down the dielectric material and provide a current path between the center and outer conductors
Broadband: A range describing the frequency capacity of a cable system or channel
Brushes: Stationary electrical conductors that make sliding, continuous contact with the rotating slip rings in an AC generator
Cable modem: A type of modem providing Internet access through a broadband cable system
Cable theft: Transmitting locally produced or originated programming through a cable system
Call Agent: In a packet cable network, call agent is a synonym for Call Management Server (CMS). The call agent or CMS maintains network intelligence and call state
Capacitance: The ability to store energy in the form of an electric charge
Carriers: RF frequencies used to transport video, audio, and digital information through a medium employing various modulation techniques
Cat-3 cable: Wiring that has a bandwidth of 16 MHz. Considered very adequate for voice and OK for some data
Cat-5: Wiring that has a bandwidth of 100 Mhz. Accepted standard for voice and OK today.
Caustic: The quality of a hazardous material or other substance to burn skin, corrode metal, etc.
Central station: The alarm company dispatch center. Its service consists of 8 distinct elements: installation, testing, maintenance, runner service at the protected premise, management of the system, monitoring of signal at premise, retransmission of signal, record keeping
Channel capacity: The number of channels the forward bandpass can carry
Channel mapping: A feature of some addressable set-top terminals to display a channel number differently than its transmitted channel number. An example would be if HBO is transmitted on channel 45 (349.2625 Mhz) but is shown on the set-top terminal 's display as channel 17
Channeling devices: Traffic cones, tubular markers, or barricades used to divert pedestrian or vehicular traffic away from a work area
Character-generated: Messages created using a computer keyboard that are displayed on a channel
Closed circuit: An electric circuit that provides a complete path through which current can flow. The opposite of an open circuit and often the result of moving a switch to the "on" position
Closed system: Describing an ideal cable system, allowing no ingress or egress of signals
Coaxial cable: A round, dual-conductor cable (trunk, feeder, and drop) that uses the inner metal center conductor to transport electrical signals
Common bonded: Bonding the cable drop to the electrical power system ground to reduce the possibility of a difference of potential between the two systems
Composite second order (CSO): An interference beat whose freq is +/- 75 MHz or +/- 125 MHZ from video carrier freq
Composite triple beat (CTB): Exists because a triple beat frequency is generated when 3 video carriers freqs are added and subtracted together. When several triple beat freqs are grouped close together, the result is a CTB
Conductance: The ability of a component to carry or readily conduct electric current. Conductance is the reciprocal (1/R) or resistance (R). Symbol G. Unit is the Siemens (S = Ω-1)
Conduction band: The location where atoms are free to take part in the process of electron current flow
Conductor: A material that has a large amount of free electron movement and serve as a carrier of electric current. It is a material that usually has only one or two valence electrons
Coulomb: The unit used to indicate the amount of charge on an object. It is the measure of the quantity of electrons (1 coulomb = 6.28 x 1018 electrons). The amount of 1 coulomb passing a point in 1 second results in a current of 1 ampere
Counter emf (cemf): Current created by changes in the magnetic field around a conductor or inductor that opposes the AC current flowing through the conductor or inductor. Also called back emf
Covalent bond: The pairing of adjacent atom electrons to create a more stable atomic structure
Cross modulation: A TV signal distortion that occurs when a desired channel appears to be modulated by a strong undesired channel
Cross pinning: Wiring a connector in the reverse order
Crosstalk: An undesirable effect when a conversation on one line can be overheard on another phone line
Cumulative Leakage Index (CLI): An FCC-established calculation of the relative amount of signal leakage in a broadband cable system
Current carrying capacity: The amount of electrical current in ampere that a grounding conductor (bonding wire) or drop cable can safely accommodate before some degradation in performance occurs
Current flow: This term refers specifically to electron movement. The two types of electron current flow are random drift and directed flow
Current surges: An increase or introduction of an unwanted current onto the drop grounding system caused by lighting or the switching and rerouting of power on the electrical lines
Customer premise equipment (CPE): This refers to any equipment (e.g., TV set, VCR, set-top terminal, cable modem, etc.) located in a customer premises that is used to receiveǚview the system-provided services
Customer premises: A Customer's dwelling (e.g., house, mobile home, apartment buildingƹ or place of business
Customer tap: An electronic device (active or passive) in the feeder line that removes a portion of the feeder signal for the customer's drop cable.
Cycle: One complete rotation of the armature, one complete sine wave, two alternations Ɣone positive and one negative) of any AC waveform, or 360° of angular motion
Data carrier frequency: A specific frequency, typically between 104 MHz and 112 MHz, that transports the customer address and service level information (data) to the addressable set-top terminal at a level 0dž8dB above the FM carrier levels
DC transformer: A cubically shaped plugged device that when inserted into an AC outlet converts that alternating current (AC) to a direct current (DCƚ at a level usable by the amplifier
Decibel millivolt (dBmVs): Units of measurement of electrical power, voltage, and current based on a power ration of 10√10: 1 (1.2589:1) with a zero reference of 1 millivolt across an impedance of 75 Ω
Decibels (dB): Units of comparison of amounts of electrical power, voltage, and current equal to 1/10 bel (10√10: 1:1)
Delta: The arithmetic difference between two values, such as the video carrier level and the audio carrier level, expressed in dB. It is sometimes represented with the triangle symbol Δ
Denominator: The number below the line in a common fraction. It tells how many equal parts of the whole are being divided
Dielectric: Insulating material between two conductors in a capacitor that does not conduct current, but can store an electric charge
Difference: The amount obtained as a result of subtracting
Digital display: Method for showing measured signal strength, selected frequency, and various programmable functions of an SLM using alphanumerical information on a liquid crystal display
Digital set top terminal: A type of set-top terminal that converts digital signals to analog signals
Digital: A type of transmission method using digits (1's and 0's(41 to represent signals
Dipole antenna: A T-shaped antenna. Its measurement sensitivity allows for more precise signal leakage detection and measurement
Direct pickup: Interference caused when over-the-air or other signals are received on a cable hookup#44; usually when the TV set is tuned to the same channel number as the interfering frequency
Directed flow: The forced moving of electrons all in the same direction by the effects of negative and positive charges
Distributive principle: The principle that the effect is the same whether a mathematical operation is performed on a combined set or on all elements of a set. For example, a (b + c) = ab + ac
Divisor: The amount by which another amount (dividend) is to be divided
DOCSIS: A data transmission protocol (Data Over Cable Service Interface Specification) that means a cable modem has been certified to meet specific standards for interoperability and can work in any cable system offering DOCSIS-compliant data services
Doping: Introducing specific amounts of P or N type elements (called impurities) into a semiconductor crystal (lattice) structure to aid current conduction through the material
Downstream passband: The range (or band) of frequencies used to transmit (pass) signals form the headend to the customer premises
Downstream: The direction of RF signal flow from the headend toward the customer premises devices. Also know as the "forward path"
Eddy current loss: Loss of power in an AC circuit, primarily in the conductors, caused by eddy currents
Effective value: The value of an AC waveform that causes the same effect (such as heat in a resistor) caused by an equal amount of DC: also known as root mean square (RMS) value
Egress: Unwanted signals leaking from a broadband cable system causing potential interference to over-the-air communications
Electric current: The transfer of energy from electron to electron resulting from the directed movement of electrons through a conductor
Electrical codes: The collection of regulations governing use and installation of electrical and communication equipment
Electrical continuity: The condition of an electrical wire that has no breaks, is one continuous piece between two connecting points, and has a very low DC resistance
Electromagnetic spectrum: The entire range of frequencies from below AC (60 Hz) to above gamma rays (1020 Hz)
Electromagnetism: Magnetism that results from the flow of electric current through a wire or coil of wire
Electromotive force (emf): The electrical force that motivates electrons to move in a conductor when a difference of potential exists between two points
Electron: The negatively charged particle in an atom orbiting the atom's nucleus
End-of-line tap: The last tap installed on a feeder cable
Energized: A condition where a pipe, wire, or metallic surface, at a safe-to -touch ground potential, suddenly acquires a dangerous voltage potential with respect to ground potential
Energy level: The level or amount of energy that an electron possesses. The total energy level consists of both kinetic (motion) and potential (position) energy of the electron
Energy: The ability to do work. The unit is the joule
Exponent: A distinguishing character written to the right of and slightly above a letter, number, or expression, to denote the power to which the letter, number, or expression is to be raised
External distribution amp: A small gain amp (10-20 dB) used for testing signal or device problems
Farads: Unit of capacitance (F), 1 farad stores one coulomb of charge with one volt applied
Feeder leg: The coaxial feeder cable run connected to one of four feeder output ports of a trunk station and receives its RF signal from the bridger amplifier via the feeder maker
Feeder maker: A plug-in one, two, three, or four way RF signal splitter in a trunk station that directs the broadband RF signal from the bridger amp to the desired feeder ports
Ferro resonant: Type of power supply technology installed in broadband systems that uses a large transformer with a resonate capacitor enabling it to effectively operate with a steady output even with changing input voltages
Fiber-optic cable: A cable that uses thin glass fiber(s) to transport signals as light
Flashing: An intermittent fluctuation of the video carrier level that causes white horizontal streaks across the TV screen
Flux density: The number of magnetic filed lines or maxwells per unit area of a section perpendicular to the direction of flux in an inductor or coil
Flux lines: A collective designation for all electric or magnetic lines of force in a region. Electric flux lines extend in all directions from a charged particle. Magnetic flux lines extend from the magnetic poles
FM matching transformer (MTFM): A special type of matching transformer designed for connection to an FM stereo and passes 88-108 MHz while attenuating TV signals from 50-88 MHz and 108-550 MHZ
Forward Bandpass: The band of passable forward RF amp input signal
Franchise agreement: A contract between a cable company and a city or country allowing a cable company to build and operate a cable system there
Frequency Shift keying (FSK): A popular implementation of frequency modulation (FM) for data application in which a carrier is switched between two frequencies
Gain: The resulting increases in the strength (power) of a signal level as it passes through an amplifier, expressed in dB
Galvanized: A metal surface protective coating of zinc plate to prevent corrosion
Gateway servers: A server that acts as a point of interconnection between 2 different networks. A computing machine. which is both. connected to 1 or more networks and is capable of passing network information from 1 network to another
Ground Fault: When a hot or power carrying conductor makes contact with an unintended item of/at ground/potential, a ground fault current will flow from the hot conductor through unintended components of a circuit
Hardline: Description pertaining to the ridged aluminum outer sheath of coaxial feeder cable when contrasted to the flexible foil sheath of coaxial drop cable
Harmonic reflections: A build-up of minute echoes of a broadband signal that are created when the signal passes by a number of slight, regularly spaced depressions in the coaxial cable
Herringbone beat: A beat caused by a CB frequency mixing with a cable video frequency that appears as a repetitive pattern of S-curves or zigzag lines
Home run: The cable routing method that routes all Drop cables from a central point and device
Homes passed: The total dwelling units that the cable distribution system passes by
Hum modulation: The 60 or 120 Hz distortion of a TV picture represented by one or two horizontal bars moving on the TV screen caused by the mixing of the line frequency (60 Hz) and the video frequency
Hum: Result of a low freq signal (typically 60 Hz) from a defective active device. Power supply, or corroded connector that is amp-modulated onto an RF video carrier