When you are about to design an analog CCTV project it is crucial to know which CCTV coaxial cables can be used and how they affect the overall quality of the system that will be installed.
Let's talk about the best coaxial cables for CCTV.
In this article, we will talk about coaxial cables widely used in analog CCTV systems to send the images from the camera to the recorders.
The construction of a coaxial cable
A coaxial cable is constructed to allow the transmission of the signals and, at the same time, protect against external electromagnetic interference.
In the image above we can see the parts of a coaxial cable:
When a camera is connected using a coaxial cable to a monitor or recorder, the braid is used to protect the center conductor from external interference.
The dielectric is used to insulate the center conductor from the braid and the outer jacket is designed to protect the cable.
Due to this need for protection of the coaxial cables for CCTV we must use quality material such as conductors with a higher percentage of braid (95% is a good example).
The distance from the installation of a camera is directly affected by the quality and thickness (gauge) of the coaxial cable used.
Types of coaxial cables for CCTV
When we are working on a project or visiting a store to buy the installation material we are faced with the question of which coaxial cables for CCTV we should use, cables such as RG59, RG6 and RG11 are available at the market and we must decide what is ideal for the project.
In the image above we note the gauge difference between coaxial cables.
The higher the cable gauge, the better the transmission for long distances, and we must also consider the fact that higher resolution cameras can transmit more quality images over shorter distances when compared to low resolution cameras.
I think you remember cameras with different analog resolutions like 380, 420, 540 and 600 TVLs, right?
So when you want to stream videos with 600TVL cameras for example, you need to be careful about using the correct cabling because there are differences in the maximum distance for transmission relative to resolution and also an issue with color or black and white image. You will soon notice problems with transmitting color images when not using proper cables.
Coaxial cable distances for CCTV
Based on the fact that today we hardly buy low resolution cameras, after all we want to keep a minimum quality for our projects, here is a table for a quick consultation of the color transmission distances for 600 TVL cameras.
Cable | Distance | Resolution | Impedance |
|---|---|---|---|
RG-59 | 150m (492 feet) | 600 TVL | 75 Ohms |
RG-6 | 200m (656 feet) | 600 TVL | 75 Ohms |
RG11 | 390m (1280 feet) | 600 TVL | 75 Ohms |
In summary, use coax cables with more quality in terms of percentage of braid, cable gauge, If the cameras have interference problems or color issues that can be the case where the cables are not appropriate for the installation.