CCTV cables, also known as video transmission cables, are essential to any surveillance system, whether it is a commercial or residential installation. These cables are primarily used to transmit video signals from CCTV cameras to the monitoring equipment such as digital video recorders (DVRs) or network video recorders (NVRs).
When it comes to CCTV cables, it is crucial to choose the right type of cable for your needs. There are two primary types of CCTV cables: coaxial and twisted pair cables. Let’s take a closer look at each.
Coaxial Cables
Coaxial cables are the most common type of CCTV cable on the market. As the name suggests, they have a central conductor surrounded by a layer of insulation, which is then wrapped in a metallic shield and an outer jacket. The metallic shield is made up of a series of braided wires that work to prevent any interference from other electronic devices and electromagnetic fields. Coaxial cables are known to provide clearer images, are less expensive, and are more durable than twisted pair cables.
Twisted Pair Cables
The second type of CCTV cable is twisted pair cables. These cables consist of two wires twisted around each other, which helps decrease any electromagnetic interference. Twisted pair cables are typically more expensive and are used less frequently in CCTV installations, primarily because they are more sensitive to interference from other electronic devices. However, these cables are ideal when installing IP cameras, and their use is growing due to the increase in digital recorders, cybersecurity, and remote access.
RG-59 and RG-6 are the most popular Coaxial cables used in CCTV installations, with RG-6 being an upgraded version of RG-59. RG-6 cables are thicker and can transmit video signals at higher frequencies, giving more bandwidth than RG-59 cables. They are also more durable, can transfer signals over greater distances than RG-59, and tend to offer better shielding for electromagnetic interference.
There is a vast array of choices within each type of CCTV cable, the two most critical aspects to choosing the correct CCTV cable are distance and signal strength. If the distance is longer than 500ft between the camera and the monitoring equipment, it’s best to use RG-6 cables. For distances shorter than 500ft, RG-59 is suitable.
When it comes to signal strength, CCTV cables have a measured attenuation value as the signal strength decreases over longer distances. Attenuation shows how much signal is lost per foot to determine signal strength over distance. The general rule of thumb is to use the highest grade of cable based on the distance you need. Most CCTV cables come with a specified range, quality, shielding, and expected attenuation loss in dB per 100ft or 100m. This information helps installers determine the best CCTV cables required to match their specific installation needs.
Another factor that determines the type of CCTV cable to use is the environment in which it will be installed. For instance, if a CCTV cable runs underground, it requires more protection and shielding to withstand the harsh elements such as exposure to water and dirt. Suppose a cable runs through a dry location without any environmental factors. In that case, a single jacket cable would suffice. This is called a direct burial cable that’s waterproof and generally UV-resistant.
When installing a CCTV system, it’s also critical to ensure that the cable has the right connectors. A common connector for CCTV installation is BNC’s connector, which provides excellent shielding and is the most common connector type used in the industry. One important thing to note is that when changing distances, the connectors used can play a significant role in overall quality. F connectors are another option that is good for running through walls and used more in residential or CATV connections.
In conclusion, choosing the right CCTV cables may seem daunting. However, doing some research and understanding your needs based on distance, the environment, and the connectors required, will help ensure that you get the right CCTV cable for your surveillance system. Coaxial cables tend to offer a better image quality, are more durable, and are less expensive, while twisted pair cables are more sensitive to interference and are primarily used when installing IP cameras. Don’t forget to check your attenuation loss specifications to match your cable’s distance requirements. As always, it’s a good idea to work with a reputable installer or cable provider to ensure that your CCTV cables provide the best results.