• CAI Approved System Installer - An associate that has a number of engineers who're accredited with the design, installation and upkeep of systems.
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• Capacitance - A energy hard drive that's created wherever an insulator separates two conductors between that your current difference is available. Capacitance is measured in "Farads".
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• Cassegrain - A satellite dish that has a paraboloid primary focus main reflector and also a convex sub-reflector.
  


• Cat5 - Cat5 is a generic term mainly used for Category 3, 5, 6, 7, 8 ‘twisted pair’ cable that is used in structured networks.
  


• Cat5E - Enhanced’ Cat5 cable in which the individual twisted pairs are generally twisted in varying levels of ‘tightness’ together per pair. When utilized in audio /video systems it will help in conquering problems such RGB ‘skew’ and audio unbalances etc.
  


• CATV - Community Antenna Television. An expert antenna and distribution system able to receiving, increasing and disbursing a tv signal using a coaxial or fibre cable to television devices inside a large community. Also called 'Cable Television'.
  


• CDMA - Code Division Multiple Access. A statistical standard for data transmission.
  


• CE Mark - Consultants Europe. Certification Scheme for equipment compliance.
  


• Ceefax – The teletext service from the BBC
  


• Chrominance - The hue and saturation within the colour. A chrominance signal carries the colour information.
  


• Cinemascope - Widescreen Television picture size, usually 16:9.
  


• Clarke belt – The circular orbital belt 35 786Km above the equator, where the satellites appear to be stationary.
  


• COAX - Coaxial cable, a middle performing wire separated from an outer braid conductor with a dielectric (insulator). The braid surrounds the dielectric so when linked to ground, prevents (shields) the center conductor from radiating energy. The spacing between conductors, composition from the dielectric and dimensions from the conductors determine the impedance from the cable. Coax can be used to transfer rf energy in the transmitter towards the antenna.
  


• COFDM - Coded Orthogonal Frequency Division Multiplex. The way of modulation used for digital terrestrial broadcasts in the UK.