Analogue CCTV explained

Analogue CCTV Explained

Analogue and Digital are different ways of interpreting real world signals. From a technology stand point you can think of it as comparing vinyl records to CDs. On vinyl (Analogue) records you get the clicks and whistles created by dust and static on the record, these are natural additions add by the environment. On a CD (Digital), the information is store in 0’s and 1’s which are translated to something you can see or hear without any other “interface”.

For an analogue system you will need:

  • A Digital Video Recorder (DVR)
  • Analogue camera(s)
  • Hard drive – Only one needed
  • Cables- one per camera
  • Cable clips
  • Power supply – only one needed for all cameras
  • Power splitter – only one needed
  • CCTV monitor screen or your own TV to view it on
  • HDMI cable to connect your screen

Analogue CCTV uses coaxial cable to carry an image, the same as your satellite cable. You will also need a power cable for each camera which is typically 12 Volt DC. A PoC system will not require power cables.

If you want sound as well, then a separate pair of cable will be needed.

What’s the downside of analogue?

Analogue can suffer from interference. If there’s a poor connection the image will display wavy lines or spots. On industrial sites you will often see rolling lines due to three phase electricity causing interference.

Coaxial cable can be a problem to hide under carpet in comparison to Cat5.

Separate cables are needed for advanced functions such as physical motion detection (PIR) and audio recording. At least one cable must be directly connected from DVR to a single camera. All these cables make analogue a poor choice for large areas/distances such as a shopping malls or between buildings.

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