Friday, January 11, 2013

Cables for CCTV Systems

<Coaxial Cable>

  Coaxial CCTV cable is used to transmit signals from the surveillance camera to monitor. Among various coaxial cables, RG59/U with a 75-ohm impedance is most popular and can be installed up to 450ft distance without any quality lose. BNC connectors are used to connect both ends of this cable

<Fiber-Optic Cable>

 Fiber-Optic Cable has good electrical features, it is not affected by electrical interference and has good performance even under high-voltage power. It transmits video signals with extremely high efficiency and can run up to miles. It is a pity that Fiber-Optic Cable is expensive and hard to control

<RCA Cable>

  RCA cable is not standard but it is widely used in the market, specially for short distances up to 250ft. Although its transmission quality is worse than Coaxial Cable or Fiber-Optic, RCA cable is still widely used because of its easy use and no video signal lose up to 250ft distance.

<DIN Cable>

  Most observation systems pre-assembled at the factory have DIN cables with DIN connectors at both ends. DIN cables have 5 or 6 wires inside, for example, wire 1 is for video, wire 2 is for audio, wire 3 is for power(12VDC, positive), wire 4 and 5 are for speaker(positive and negative), wire 6 is for ground. Mini DIN cable, which is used for mini camera package, has 4 wires inside. DIN cable, large or mini, can run up to 250ft distance without any video quality loses.

<Cable Tie>

  Because the transmission of video signals has tight relationship with the spacing between the inner wires or conductor and shield, any changes in the distance between the wires or conductor and shield can result in decreasing picture quality. This is the reason why you need to use suitable cable tie which are sold at any hardware or electrical parts shops when working with Coaxial Cable or DIN cable.

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