Not all coaxial cable should be used for CCTV camera installations. RG59 coax cable is the industry standard and best choice for CCTV systems and HD over coax systems, however, not all RG59 is created equal. Be sure to read the spec before you buy.
This is what you need to know. Be sure to select RG59 cable with a solid copper core / inner conductor and 95% copper braiding. Look at the specification in the above image. These two elements are highlighted and the arrows point to the parts of the cable they refer to. The impedance of CCTV cameras is 75 ohms. In order to have minimum video loss, you should use coax cable that also has an impedance of 75 ohms. Coax cable is also available in 50 ohm and 93 ohm. Do not use these for CCTV installation. Use ONLY 75 ohm cable.
RG6 can also be used for CCTV. It is also available with a solid copper core / inner conductor and 95% copper braiding. RG6 can be run farther distances than RG59 without video loss, however, RG6 is a thicker, more rigid cable which is not as convenient to work with (especially around corners). RG59 is rated at 700 feet and RG6 is rated at 1000 feet for analog CCTV. RG59 is more typically used.
Can I use CATV Coax Cable for CCTV?
Like CCTV, cable television (CATV) is also typically wired using RG59 or RG6 coax cable, however it is not the same type of RG59 or RG6 that is used for CCTV installations. The difference is that the center conductor / inner conductor of CATV grade cable is made of steel or copper plated steel instead of copper. Steel has a much higher resistance than pure copper which leads to video loss at low frequency. Steel costs less than copper, which makes CATV cable cheaper than CCTV.
CATV systems are able to use cable with a steel center because cable TV video uses much higher video frequencies than CCTV. The copper plating of clad cable is thick enough so that none of the radio frequency energy penetrates into the steel core to induce loss. CCTV video uses much lower frequencies which are lost or dropped when using steel or steel clad cable.
To identify RG59 or RG6 for CATV, check the product specification and be on the lookup for terms such as “copper clad steel”, “aluminum foil inner shield”, “aluminum braid shield”. These are all characteristics coax cable that is used for CATV cable and should not be used for CCTV.
What about Cable for HD CCTV (AHD, TVI, CVI)?
HD CCTV technologies such as AHD cameras and TVI cameras also operate at low frequency – similar to analog CCTV. You should use RG59 or RG6 with a solid copper core and 95% braided shielding for HD security camera installations. These systems, knows as “HD over coax” us the same cable as traditional analog CCTV, however high quality cable for these systems is even more important because of the higher bandwidth requirements of the video.
What about Cable for 3 Megapixel, 5 Megapixel, and 4K Resolution?
The technology for “HD over coax” security camera systems continues to improve. 3 megapixel, 4 megapixel, 5 megapixel, and even 4K HD CCTV cameras are available. HD over coax DVRs that support these resolutions are also now available. If you wire your system with high quality RG59 coax cable now, it will be ready to upgrade to any of these camera types in the future.