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 of 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.