C-band

Used loosely for satellite downlinks within the 3.4 to 4.2 GHz frequency range.

C/T

Carrier-to-noise-Temperature ratio.

C/I

Carrier-to-interference ratio.

C/No or C/kT

Carrier/Noise Density, i.e., CNR per unit bandwidth.

C.S.A.

Abbreviation for Canadian Standards Association, a non-profit, independent organization which operates a listing service for electrical and electronic materials and equipment. The Canadian counterpart of the Underwriters laboratories.

Cable

An insulated conductor, or group of individually insulated conductors in twisted or parallel configuration.

Cable Assembly

A completed cable and its associated hardware ready to install.

Cable Drop

Cable Drop or drop cable is that portion of a cable system that connects individual customers to the cable system. The drop begins at a connection point on the cable tap and ends at the customer's television.

Cable television (CATV)

A system that transmits original programming, and programming of broadcast television stations, to consumers over a wired network, whether strung across poles overhead or laid underground.

Cablewallah

Indian lingo for cable operator.

Cabling Factor

Used in the formula for calculating the diameter of an unshielded, unjacketed cable. D = Kd. where D is the diameter, K is the factor and is the diameter of one insulated conductor.

Cabling

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

Capacitance

The ratio of the electrostatic charge on a conductor to the potential difference between the conductors required to maintain that charge.

Carrier

A pure-frequency signal that is modulated to carry information. In the process of modulation it is spread out over a wider band. The carrier frequency is the center frequency on any television channel.

Carrier-to-Noise Ratio (CNR)

The ratio of the received carrier power to the noise power in a given bandwidth expressed in decibels. The CNR is an indicator of how well an earth receiving station will perform in a particular location, and is calculated from satellite power levels, antenna gain and the combined antenna and LNA noise temperature.

Cassegrain Feed System

An antenna feed design that includes a primary reflector, the dish, and a secondary reflector which redirects microwaves via a waveguide to a low noise amplifier.

Cassegrain

Dual-refiector antenna geometry using a convex hyperboloidal subreflector and paraboloid main reflector.

CATV

An abbreviation for Community Antenna Television - another name for Cable TV.

CBD

"C-band Direct" (broadcast). Proposed name for a formalized home TVRO system in the US.

CCD

Charge coupled device. In this device charge is stored on a capacitor which are etched onto a chip. A number of samples can be simultaneously stored. Used in MAC transmissions for temporarily storing video signals.

CCI

Co-Channel Interference.

CCIR

International Radio Consultative Committee.

CDMA

Code Division Multiple Access.

Channel

A segment of band width used for one complete communication link.

Characteristic Impedance

The impedance that, when connected to the output terminals of a transmission line of any length, makes the line appear infinitely long. The ratio of voltage to current at every point along a transmission line on which there are no standing waves.

Chrominance

The hue and saturation of a color. The chrominance signal is modulated onto a 4.43 MHz carrier in the PAL television system and a 3.58 MHz carrier in the NTSC television system.

Chrominance Signal

The color component of the composite baseband video signal assembled from the I and Q portions. Phase angle of the signal represents hue and amplitude represents colour saturation.

Circuit

A two-way communications link, most commonly used for sending and receiving voice and data information. Satellite capacity is most often stated in the number of circuits that a satellite can carry.

Circular Mil

The area of a circle one mil (.001") in diameter, 7.854 x 10^-7 sq.in. Used in expressing wire cross sectional area.

Circular Polarity

Electromagnetic waves whose electric field uniformly rotates along the signal path. Broadcasts used by intelsat and other international satellites use circular, not horizontally or vertically polarized waves as are common in North American and European transmissions. Circularly polarized waves are used for satellite telephony because Faraday rotation does not alter their behavior.

Cladding

A method of applying a layer of metal over another metal whereby the junction of the two metals is continuously welded.

Clamp (also Line Clamp, Black Level Clamp)

A video procession circuit that removes low-frequency disturbances (e.g. energy dispersal) from the waveform

Clarke Belt

The circular orbital belt at 22,247 miles above the equator, named after the writer Arthur C. Clarke, in which satellites travel at the same speed as the earth's rotation. Also called the geostationary orbit.

Co-Polar(ized)

Of the same polarization.

Coaxial cable

Cable with several common axis lines under protective sheath used for television signal transmissions.

Code Division Multiple Access (CDMA)

A transmission system that superimposes the audio or data information onto a specific coded address waveform.

Codec

Coder/Decoder system for digital transmission, e.g. of television.

Collocation

Ability of multiple satellites to share the same approximate geostation orbital assignment.

Color Subcarrier

A subcarrier which is added to the main video signal to convey the color information. In NTSC systems, the color subcarrier is centered on a frequency of 3.579545 MHz, referenced to the main video carrier.

Color Code

A system for circuit identification through use of solid colors and contrasting tracers.

Color Bars

A test pattern of specifically colored vertical bars used as a reference to test the performance of a color television

Colour Burst

A synchronizing signal contained within the composite video waveform which serves as a frequency and phase reference for the chrominance information.

Common Carrier

A company providing telecommunications services to users under rates and regulations set by the Federal Communications Commission.

Companding

A noise-reduction technique involving compression applied at the transmitter, with complementary expansion at the receiver. A form of noise reduction using compression at the transmitting end and expansion at the receiver. A compressor is an amplifier that increases its gain for lower power signals. The effect is to boost these components into a form having a smaller dynamic range. A compressed signal has a higher average level, and therefore, less apparent loudness than an uncompressed signal, even though the peaks are no higher in level. An expander reverse the effect of the compressor to restore the original signal.

Composite Signal

Ambiguous term, variously used to refer to composite baseband or composite video.

Composite Baseband

The raw demodulator output, prior to filtering and clamping and (usually) prior to de-emphasis. Contains all transmitted subcarriers. In some receivers this output is not intended for video use, and a roll-off may be applied to the lowest baseband frequencies.

Composite Video

Complete video signal including synchronizing, luminance and color information, with teletex where transmitted. Does not include audio or data subcarriers.

Concentric Stranding

A central wire surrounded by one or more layers of helical wound strands in a fixed geometric arrangement.

Concentricity

In a wire or cable, the measurement of the location of the center of the conductor with respect to the geometric center of he surrounding insulation.

Conductivity

The capability of a material to carry electrical current - usually expressed as a percentage of copper conductivity (copper being 100%).

Conductor

An uninsulated wire suitable for carrying electrical current.

Conduit

A tube or trough in which insulated wires and cables are run.

Conical-scan

A complex type of autotracking system.

Connector

A device used to physically and electrically connect two or more conductors.

Continuity Check

A test to determine whether electrical current flows continuously throughout the length of a single wire or individual wires in a cable.

Contrast

The ratio between the dark and light areas of a television picture.

Converter

Indian lingo for a device which when attached to a television increases its channel tuning capability. (See S-band tuner and box)

Copolymer

A compound resulting from the polymerization of two different monomers.

Copperweld

The trade name of Flexo Wire Division (Copperweld Steel Corp.) for their copper clad steel conductors.

Core

In cables, a component or assembly of components over which additional components (shield, sheath, etc.) are applied.

Coverage

The percent of completeness with which a metal braid covers the underlying surface.

Crazing

The minute cracks on the surface of plastic materials.

Cross Modulation

A form of interference caused by the modulation of one carrier affecting that of anothe@ signal. It can becaused by overloading an amplifier as well as by Signal imbalances at the headened.

Cross Polarization

Term to describe signals of the opposite polarity to another being transmitted and received. Cross-polarization discrimination refers to the ability of a feed to detect one polarity and reject the signals having the opposite sense of polarity.

Cross-Site

Link or cable connection between antenna and equipment building.

Crosstalk

Interference between adjacent channels often caused by cross modulation. Leakage can occur between two wires, PCB tracks or parallel cables.

Cut-Through Resistance

The ability of a material to withstand mechanical pressure, usually a sharp edge or small radius, without separation.