Security Camera King sells SC500 RG59 Siamese cable to make your cabling runs fast and easy. For less than $100 you can purchase 500 feet of Siamese RG59/18-2 cable in either black or white. Professional security companies have used this cable for years, so this article is designed more for the novice do-it-your-selfer. In the following article well discuss cabling and why this type of cable is used.
First, let’s review what makes up a digital video security system and how it works. A typical digital video security system consists of one or more digital video cameras, a Digital Video Recorder or DVR, and one or more monitors (although many systems only require a monitor for set up, and after it is up and running, the system can do without the monitor at all.)
The digital video camera is responsible for capturing light images and converting them into digital video data. This data can be stored on the DVR or some other device and even used in real-time (live) to view the camera’s field of vision on a monitor. To do all of this, items are required in addition to the already mentioned components: 1) Video transmission cable to carry the video data from the camera to the DVR; and, 2) Power in the form of electricity. Since shooting the electricity through the air is just a bit too futuristic at this point, a power cable that transfers the power from a power distribution box or plug-in supply is also required.
SCK’s SC500 RG59 cable is the perfect solution. This cable consists of a sheathed and shielded RG59 coaxial cable wrapped with two 18-guage power supply wires. Why RG59 and 18-2? These are two of the best options for getting the job done.
Back before we used analog (and, therefore digital) security cameras, there were only television studio cameras. These cameras and video security cameras are basically the same machine, accept the security camera was smaller, used a smaller lens, and initially didn’t have the fine tuning adjustments that could be made on a studio camera.
The television studio cameras had to send their data along video transmission cables, just like security cameras. However, their power requirements were huge and usually a much bigger video transmission cable was used. In addition, once the cameras signal reached the studio control center, it was fine tuned and amplified many times so it could be beamed out a fairly large antenna either at the studio or somewhere near the studio.
To receive the television signal required a receiver, the television, had an antenna. Any one within range of the signal could receive it if they had a good enough location and antenna. (This “Open” broadcasting is why they often call security systems “CCTV or Closed Circuit TeleVision. There were no antennas and the signal was sent directly from the camera to the user’s monitor and video recorder in a “closed circuit” where no one else could see it.)
The impedance of a typical radio frequency (television channel) antenna is 75 ohms. Without going into great technical depth, let’s just say that at an impedance of 75 ohms the signal is not “stepping on itself or reflecting” distorting or degrading too rapidly. So if you are going to create a “CCTV circuit” the impedance of the device carrying the signal ideally should be the same as that of the antenna (in this case 75 ohms). Guess what cable happens to have an impedance of 75 ohms? That’s right, RG-59 coaxial cable.
Now you know why most professional installations are done with RG59. However, there are many other cables with different impedances that will work too, but we won’t go into that kind of depth. So, SC500 RG59 is the ideal cable for the job. Incidentally, RG59 cable should be able to carry the radio frequency signal about 1,000 feet before there is any great distortion or degradation.
The power side of our cable is 18 gauge single pair wire. Ideal for use with either Direct Current (DC) or Alternating Current (AC), this cable pair is bundled inside the jacket that also carries the RG59. That means one cable run per camera. That means it saves you time, and helps to create a neat, clean, and professional cable installation.