The coaxial power connector is the most common in the practice of video transmission and the cheapest, most reliable, most convenient and easiest way to transmit electronic images in television surveillance systems.

What Is It?

Coaxial cable is manufactured by many manufacturers with a wide variety of sizes, shapes, colors, characteristics and parameters. Most often it is recommended to use cables of the RG59 / U type, but in fact this family includes cables with the most diverse electrical characteristics. In television surveillance systems and in other areas where cameras and video devices are used, the RG6 / U and RG11 / U cables similar to RG59 / U are also widely used.

Although all these groups of cables are very similar to each other, each cable has its own physical and electrical characteristics that need to be taken into account.

The Groups for You

All three mentioned groups of cables belong to the same common family of coaxial cables. The letters RG mean “radio guide”, and the numbers denote different types of cable. Although each cable has its own number, its characteristics and dimensions, in principle, all these cables are arranged and work the same way.

The Frequency

The frequency dependence of the attenuation characteristic on the length limits the distance of application by the requirements for the resolution in the system. For systems with a high resolution (more than 400 TV lines), the following restrictions must be observed: for cables RG-59 or RC-75-4, the maximum video transmission distance is up to 300 m; For RG-11 or RK-75-7 cables, the maximum video transmission distance is up to 500 m. With a large spatial separation of the source and receiver of signals, special measures are required for galvanic isolation.

The Increase

As the length of the coaxial cable increases, the degree of interference with external noise increases, and signal attenuation increases as it passes through the cable. If a certain length of the cable is exceeded, the loss in it leads first to a decrease in the brightness, and then to the blur of the pixels and the appearance of a characteristic dark loop from the dark elements of the image.

The amount of attenuation depends on the quality of the materials used to make the cable. The linear attenuation in a coaxial cable of the RC type can be judged by its design: the larger the diameter of the internal insulation of the cables (in the cable mark designation it is indicated in millimeters after the number 75), the smaller its linear attenuation.

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