What are the ways to use coaxial cable？

What are the ways to use coaxial cable assemblies? The most common coaxial cable consists of a copper conductor isolated by an insulating material. Outside of the inner insulating material is another layer of ring conductor and its insulator, and then the entire cable is covered by a polyvinyl chloride or Teflon material sheath. . It is characterized by good anti-interference ability, stable data transmission, and low price. It is also widely used, such as closed-circuit television lines. Coaxial thin cables are generally sold at a few yuan per meter in the market, which is not too expensive. Coaxial cables are used to connect with BNC connector adaptor . The coaxial cables sold on the market are generally finished products that have been connected to BNC connector  ---BNC cable assemblies. You can directly choose them.

However, according to the analysis of the characteristics of the coaxial cable assembly, the attenuation of the signal when it is transmitted in the coaxial cable is related to the transmission distance and the frequency of the signal itself. Generally speaking, the higher the signal frequency, the greater the attenuation. The bandwidth of the video signal is very large, reaching 6MHz, and the color part of the image is modulated at the high end of the frequency. In this way, when the video signal is transmitted in the BNC coaxial cable assembly, not only the overall amplitude of the signal is attenuated, but also the attenuation of each frequency component The difference is very large, especially the attenuation of the color part is the largest. Therefore, the coaxial cable assembly is only suitable for short-distance transmission of image signals. When the transmission distance reaches about 200 meters, the image quality will be significantly reduced, especially the color becomes dim and there is a sense of distortion.

In engineering practice, in order to extend the transmission distance, a coaxial amplifier is used. The coaxial amplifier can amplify the video signal to a certain extent, and can also compensate different frequency components in different sizes through equalization adjustment, so that the distortion of the video signal output by the receiving end is as small as possible. However, coaxial amplifiers cannot be cascaded indefinitely. Generally, only 2 to 3 coaxial amplifiers can be cascaded in a point-to-point system. Otherwise, the video transmission quality cannot be guaranteed and adjustment is difficult. Therefore, when using BNC coaxial cable assemblies in a monitoring system, in order to ensure a better image quality, the transmission distance range is generally limited to about four or five hundred meters.

In addition, BNC coaxial cable components still have some shortcomings in the transmission of image signals in the monitoring system:

1) The coaxial cable itself is greatly affected by climate change, and the image quality is affected to a certain extent;

2) The coaxial cable is relatively thick, which is not convenient for wiring in intensive monitoring applications;

3) Coaxial cables generally can only transmit video signals. If the system needs to transmit control data, audio and other signals at the same time, additional wiring is required;

4) Coaxial cable has limited anti-interference ability and cannot be used in strong interference environment;

5) The coaxial amplifier also has the disadvantage of difficulty in adjustment.