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How To Easily Extend BNC Cables For Security Cameras

You know the ideal position for your security camera, but you’ve run into a problem: the cable from the DVR to the camera isn’t long enough. More importantly, if you move the camera’s position you won’t have complete coverage. Wouldn’t it be helpful if you could extend the BNC cable as much as you needed?

How to easily extend BNC cables for security cameras or splice them. You can easily extend a BNC cable using a coupler. In most instances, you won’t even need to splice the wires, but it is a possibility. Luckily splicing BNC cables is an easy and routine task.

Using a coupler will extend your BNC cable but you may wonder what they are, and what are the steps to follow if the wires need to be spliced? In the case that you need to splice some of the wires to get everything running correctly, follow the guide and information laid out in this article after familiarizing yourself with some of the components and how they work.

BNC Cable Components

A Bayonet Neill-Concelman (BNC) cable, which contains two 18-gauge wires along with a coaxial cable, is designed to send video from a security camera to the monitor or DVR. It is also the camera’s power source. When the cable is too short, a BNC connector, which is fairly inexpensive on Amazon, will easily extend it by attaching two cables.

This coupler features quick-connects on both ends, so all you need to do is attach the original BNC cable to the new one. You’ll want to pay attention to the cable ends because they’re used for different purposes. Case-in-point, one is coaxial and the other is for power, so be careful not to mismatch them.

If you do mix the ends up, there’s a good chance you won’t be able to get your security camera to turn on or be able to transmit images to the DVR properly. Most BNC cables also connect to the devices via the male ends, so you’ll also want to take note of this when you’re attaching the two BNC cables to opposite sides of the connector.

Extending BNC Cables

When you’ve run out of cable before connecting it to the camera, it’s not a big problem. You don’t have to move the camera from its prime position, you just need to extend the BNC cables with a BNC connector (on Amazon). However, before you attach the BNC connector, you do want to consider the distance. If the original cable was over 300 feet, you will need to move the camera closer. When longer cables are used signal interference and other problems can develop.

Extending the BNC cable isn’t only easy, it’s also inexpensive. The extra cable comes with the connector so you don’t have to purchase anything else. To connect the cables, remember that there are two different ends. Do not mix up power and coaxial. The connector should have come with instructions that include diagrams.

You can also find packages that come with several cables and BNC connectors so you can handle multiple cameras. Having extra cables and connectors also allows you to string longer runs, so you might not have to move a security camera that is over 300 feet away.

Splicing BNC Cables

Sometimes, a BNC connector doesn’t work and this can have a few causes. The most common one is that your security camera run is extremely long. You may have one on a garage roof away from the house or you’re monitoring a large perimeter. Whatever the reason the connector isn’t working, your next option is to splice the BNC cables.

It is a little more complicated than using a connector, but only because you’ll also have to get an adapter. You’ll have to get more of them if you have several security cameras you want to connect. With an adaptor, you’ll have to add male ends to the cables but to do this, you’ll need to know how to slice cables.

Here’s a great video showing how splicing BNC cables works, and you can also reference our written instructions below. With a little time and effort, you’ll be able to splice these cables to create your own customized security system.

How to Splice BNC Cables

An easy method to use when you want to splice two BNC cables together is to start by stripping off the covering over the wire. A small, sharp knife works best, but be careful you don’t accidentally cut the wires. After the covering is removed, you want to start carefully removing the shielding so as not to sever the wires.

The shielding is comprised of multiple layers of insulation and wire wrapped together. The inner wire is the one responsible for transmitting the signal, while the outer one is a shield that helps to prevent interference which is a common problem when functioning at long distances. To remove the shielding, you want to carefully pull the interwoven wires out of the cable using a twisting motion.

After the wires are out of the cable, cut the insulation away from the center wire, and repeat these steps on the new cable. Next, you need to connect the center wires from each cable which you can do by crimping the wires together and using a butt connector. If you want to avoid buying any additional components, you can also solder them.

Finishing Steps

If you’re not using a butt connector, you want to tape the wires together, followed by twisting the pieces into a braid. Once the wires are twisted into one, solder them together. For additional security, seal the splice with heat-shrink tubing.

Now, you’re ready to connect the two cables. You want red wires connected to red ones and the same for black wires because if you mismatch the colored cables, you could cause shortages. You can solder the wires in place or use a connector, preferably a BNC one. Once the two cable wires are connected seal it with another piece of heat-shrink tubing.


The cables aren’t always long enough to connect your security camera to the DVR and in this case, you’ll want to use a BNC connector and also make sure your camera is compatible with DVR in the first place using our article. It’s surprisingly simple to use the connector, and if it doesn’t work there are other options including splicing the cables together. It does take a little more time but you won’t have to move your security cameras, even if it’s more than 300-feet from your house.