Video balun for CCTV (how it works)

You can use a video balun for CCTV to convert from one type of cable to another. 

Balun for CCTV connected to a DVR

This type of device is very common on video surveillance projects that use analog cameras and DVRs (Digital Video Recorders).

What is a balun ?

A video balun is a device used to adapt the type of connection to allow the use of UTP (Unshielded Twisted Pair) cable to transmit the signals from an analog camera.

By using a video balun it's possible to replace the traditional coaxial cable such as RG59 or RG11 and use cat5 cables to transmit the video over long distances.

The picture shows the types of cables used with a balun for CCTV.

A pair of wires are used to connect the UTP cable to the balun and a BNC connector is used on the coaxial cable to connect to the other end of the balun.

The balun word originated from the terms balanced/unbalanced because it can convert an unbalanced signal to balanced. 

Balanced/Unbalanced Balun

With balanced signals, it's possible to transmit the signal further away because it's less susceptible to external interference.

Baluns are popular because most of the regular ones are cheap and can use Cat5e and Cat6 UTP cables to increase the camera's installation distance. 

Of course, there are different types of baluns for CCTV that vary in quality and price, so it's important to be aware that low-quality baluns can compromise the entire surveillance project with images that aren't good enough.

What are the types of baluns for CCTV ?

Passive Baluns

The baluns that don't require power to work and don't boost the signals are called passive and are used just to convert the signals to run on the cat5e or cat6 cables.

The following picture shows some passive baluns used on a CCTV installation.

As you can see, there's one pair of passive balun per camera.

The baluns always work in pairs, one is connected to the analog camera and the other one is connected to the DVR do convert the signal back to unbalanced.

With passive balun, it's possible to run cables for around 200 to 300m depending on the type of analog signal and the quality of the cable and balun that's used. 

Active Baluns

Active baluns use power to boost the signal and improve the distance the Cat5 cable runs by helping to minimize the external interference.

Depending on the type of active baluns and cable that are used on the installation it's possible to install the cameras around 1,200m away from the recorder.

As you can see, the active baluns (as known as transceivers) are installed on each side of the cable and are powered to boost the analog signals from the cameras.

Before choosing a balun for CCTV make sure it meets the requirements for the distance you need to install the cameras.

Video Power Balun

It's possible to send video and power to the camera using the same Cat5e cable by using a video power balun thus reducing the costs of running extra cables.

Such type of a balun requires that an RJ-45 connector is crimped to each end of the cat5e cable as shown in the following picture.

Video Power, and Data Balun

When an analog PTZ (Pan Tilt Zoom) camera is used in the surveillance project, it's necessary to run video, power and data over cat5e cables and that's the reason a video power and data balun is helpful. 

By using such a device the camera can be powered, transmit the video signals and also receive a command from a DVR (Digital Video Recorder) or an analog joystick.

Video: How to Install Video Balun for CCTV Camera

Here's a video to help you understand how to install video balun for CCTV cameras

FAQ (Frequently Asked Questions)

What is the difference between active and passive video balun?

The passive balun is non-powered and just converts the unbalanced to balanced signals so it's possible to transmit the camera analog signals over the Cat5e cable.

An active balun is powered and can convert and boost the unbalanced signal to balanced signals and transmit it to long distances over the Cat5e cable.

How far can you run a cat5 cable for CCTV?

The average distance is 300 meters when using passive baluns and 1,200 meters when using an active balun but those distances may vary depending on the quality of the cables, local interference, and baluns that are used on the installation. 

Can more than one BNC balun be used on a single CAT5 cable?

Yes, you can use different pairs of UTP cat5e cables to install more than one balun and transmit video for multiple cameras.

Want to learn more ? 

If you want to become a professional CCTV installer or designer, take a look at the material available in the blog. Just click the links below:

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