A video balun in CCTV (Closed-Circuit Television) is a device used to transmit video signals over twisted pair cables (such as Cat5e or Cat6) instead of traditional coaxial cables (like RG59). It converts the unbalanced video signal from a coaxial cable to a balanced signal suitable for twisted pair transmission, and then back again at the receiving end.
Types of Video Baluns:
- Passive Video Balun – Works without power, suitable for short distances (up to 300m for analog CCTV).
- Active Video Balun – Requires power, can extend video transmission up to 1-2km.
- HD Video Balun – Supports high-definition analog formats like AHD, HD-TVI, and HD-CVI.
Advantages of Using a Video Balun:
- Cost-Effective – Cat5e/Cat6 cables are cheaper than coaxial cables.
- Longer Transmission Distance – Reduces signal loss compared to coaxial.
- Interference Reduction – Twisted pair cables help minimize electrical interference.
- Easier Installation – Cat5 cables are thinner and more flexible than coaxial.
How to connect camera balun
Connecting a video balun to a CCTV camera is straightforward. Follow these steps:
Materials Needed:
- CCTV Camera (Analog, AHD, HD-TVI, or HD-CVI)
- Video Baluns (one for the camera, one for the DVR)
- Cat5e or Cat6 Cable
- DVR (Digital Video Recorder)
- Power Adapter (for camera)
Step-by-Step Guide:
1. Prepare the Cat5e/Cat6 Cable
- If the cable is not pre-terminated, strip about 1 inch of the outer sheath.
- Inside, you’ll see four twisted pairs of wires. You only need one pair for video transmission.
- Typically, the blue pair or orange pair is used.
2. Connect the Video Balun to the Camera
- Plug the BNC connector of the balun into the BNC video output of the camera.
- Take the Cat5e/Cat6 cable and connect one twisted pair to the screw terminals or RJ45 input on the balun.
- If using a screw terminal balun: Connect one wire to the + (positive) and the other to the – (negative).
- If using an RJ45 balun: Plug the RJ45 connector into the balun.
3. Connect the Other Video Balun at the DVR End
- Plug the second video balun into the DVR’s BNC video input.
- Connect the same twisted pair of the Cat5e/Cat6 cable to the balun’s screw terminals or RJ45 input (matching the polarity used at the camera end).
4. Power the Camera
- Use a separate power adapter or Power Over Ethernet (PoE) balun if applicable.
- If using a passive balun, power is provided via the adapter near the camera.
- If using an active balun, ensure it is powered at both ends.
5. Test the Connection
- Turn on the DVR and camera.
- Check the video feed on the DVR to ensure the image is clear.
Optional: Using a Power-Video Balun (PVB)
Some baluns allow both video and power transmission over a single Cat5e/Cat6 cable:
- These baluns have two connectors: BNC (for video) and DC jack (for power).
- They let you power the camera from the DVR side, eliminating the need for a separate power source near the camera.
Troubleshooting Tips
- If the image is fuzzy or missing, check wire polarity and ensure tight connections.
- If using an active balun, confirm it is receiving power.
- Avoid running Cat5e/Cat6 near high-voltage electrical cables to prevent interference.