Coax or Cat6 for CCTV? Choosing the Right Cable

The question is usually framed as a choice between two cables. It is really a choice between two camera systems, and the cable follows from that. An analog camera cannot use twisted pair, and an IP camera cannot use coax without a converter.

Deciding the camera first settles the cable in one step.

Quick answer

	Coax (analog HD)	Cat6 (IP)
Camera type	HD-TVI, AHD, CVI, legacy analog	IP / network
Signal	Modulated video, plus often a separate power pair	Ethernet data, usually with power over the same cable
Power	Separate run (siamese cable) or a local supply	Normally PoE over the same cable
Distance	Set by the format’s published limit for the resolution in use	100 m channel, then an extender or fiber
Existing cable reuse	The reason analog HD survives in retrofits	Needs a twisted pair or a converter
Direction of travel	Keeping legacy systems running	Where new systems go

The camera decides, not the cable

Analog HD formats — HD-TVI, AHD and CVI — are designed to carry high-definition video over coaxial cable, and that is their entire commercial argument. They let an existing coax installation support better cameras without re-cabling.

IP cameras do the opposite. They put video on the network, which means Ethernet, which means twisted pair for the horizontal run. Once the camera is a network device, one cable carries data and power together over PoE, and the recorder becomes a network appliance.

So the first question is not about cable at all: what is already in the walls, and what kind of recorder is at the other end?

The power difference is the practical one

This is the difference that decides most installations, and it is easy to overlook when comparing cable specifications.

Analog cameras traditionally need a separate power run. The cable that solves this is siamese: a coax core and a two-conductor power pair under one jacket, run together from the recorder or a distribution point to the camera. One pull, two connections, and a power supply or distribution box at the head end.

IP cameras normally take power over the same twisted pair that carries the data. A PoE switch or a PoE injector supplies the camera, and no separate power run exists. That removes a whole set of failure points — but it also means the cable and the switch both have to support the power level the camera needs, and a long run has a power budget as well as a data limit. PoE cabling has its own constraints, particularly in bundles.

If a site has power at the camera positions, coax is easier. If it does not, PoE is usually the cheaper answer.

Distance

For IP over Cat6, the familiar figure applies: the channel is specified to 100 meters, and PoE has its own practical limit that depends on the power drawn. Beyond that, an extender or a fiber run is required.

For analog HD over coax, the limit depends on the format and the resolution. Each of the analog HD formats publishes a maximum distance at each resolution, and the figure drops as resolution rises. The number to use is the one published by the camera or recorder manufacturer for the specific combination, not a general rule of thumb, and the CCTV coax guide covers how to work with it.

The point that matters for planning: coax is not automatically longer or shorter than Cat6. Both have limits that depend on what is being sent.

Where each one wins

Coax wins when there is existing coax in the walls, when the cameras are already analog, when power is available at the camera position, or when a recorder cannot be replaced. This is the retrofit case, and it is why analog HD exists at all.

Cat6 wins on new installations, on systems that need to grow, on anything that benefits from the camera being a network device — analytics, remote access, integration with access control — and wherever PoE removes the need for local power.

Both are reasonable in a hybrid site: keep the analog cameras on their coax, and put new cameras on Cat6 with a separate network recorder. The two systems coexist; they simply do not share a cable.

The cable spec, if you are choosing cable

If you are installing new coax, the RG6 versus RG59 comparison applies, and RG6 is the usual answer for anything beyond a short run. For a new IP installation, the choice is between categories: Cat5e and Cat6 both work, and Cat6 is the better default because it keeps 2.5G and 5G open. The jacket rating matters in both cases, because most cameras are installed in a void.

One more consideration applies to both: the camera is an outdoor device on the end of the run, and surge protection at the camera is cheaper than replacing a camera, a cable and a recorder.

Scenarios

A retail site with 12 analog cameras and existing coax. Analog HD cameras at the existing positions, using the existing coax, with a new recorder. No re-cable, and that is the entire point.

A new-build office with 30 cameras. Cat6 to each position, a PoE switch per floor, and an NVR. One cable per camera, no local power.

A warehouse with cameras 150 m from the recorder. Neither cable reaches on its own. The answer is an intermediate switch or extender — or fiber for the trunk.

A school adding cameras to an existing analog system. Hybrid: new positions get Cat6 and a PoE switch, existing coax positions stay as they are, and both recorders sit on the same network.

FAQ

Is Cat6 better than coax for CCTV? For IP cameras, Cat6 is the required cable. For analog HD cameras, coax is, and Cat6 cannot substitute without a converter.

Can I run an IP camera over coax? Not directly. A converter pair is needed, and it is usually cheaper to run the right cable.

Can I use Cat6 for an analog camera? Not without a balun on each end. This is done in some retrofits, but it adds a conversion point to every camera.

What is siamese cable? A single jacket containing a coax core and a two-conductor power pair, used for analog cameras so that one pull carries both.

How far can CCTV cable run? For IP over Cat6, the channel is specified to 100 meters. For analog HD over coax, the limit depends on the format and resolution, so use the manufacturer’s published figure.

Do IP cameras need a separate power cable? Usually not. PoE supplies them over the data cable, provided the switch and the run support the power requirement.