How to Test RF Coaxial Cable?


The quality of RF cable and coaxial cable directly affects signal transmission and unnecessary loss. The section of a standard RF coaxial cable is very round. The outer surface of the cable is shielded and aluminum foil is attached to the outer surface of the insulating medium. The rounder it is, the better its performance will be.

一、First observe the roundness of the insulating medium: the section of the standard RF coaxial cable is very round, and the outer shielding of the cable and the aluminum foil are attached to the outer surface of the insulating medium. The rounder the outer surface of the medium, the smaller the gap between the aluminum foil and its appearance , the less rounded the larger the gap. Practice has proved that the smaller the gap, the better the performance of the cable. In addition, the air in the large gap is easy to invade the shielding layer and affect the service life of the cable.

二、Check the consistency of the insulation medium of the coaxial cable: the fluctuation of the diameter of the insulation medium of the coaxial cable mainly affects the echo coefficient of the cable. This inspection can cut out a section of the insulation medium of the cable, and carefully check the outer diameter of each point with a micrometer to see if they are consistent. .

三、Check the quality of aluminum foil: Aluminum foil plays an important shielding role in coaxial cables. It plays an important role in avoiding external open circuit signal interference and preventing cable TV signal leakage. Therefore, the quality of aluminum foil should be tested for new coaxial cables. First, cut open the sheath layer, and observe whether the surface of the braided network cable and the aluminum foil layer maintains a good luster; secondly, take a section of cable, wrap it tightly on a small metal shaft, straighten it and turn it in the opposite direction, and repeat it several times. Then cut the cable sheath layer to see if the aluminum foil is cracked or not. You can also cut out a small piece of aluminum foil and rub and stretch it repeatedly in your hands. For defective products.

四、Check the braided mesh of the coaxial cable: The braided mesh of the coaxial cable plays an important role in the shielding of the coaxial cable, and whether it is in the centralized power supply cable TV line or the return line of the power supply, the quality inspection of the coaxial cable must be based on the textile Check carefully whether the net is tight and flat. The method is to cut the outer sheath of the coaxial cable, cut a small section of coaxial cable braided net, and identify the number of braided nets. If it matches the given index value, it is qualified. The first textile mesh wire is measured with a spiral micrometer. Under the comparison at the same price, the thicker the wire diameter, the better.

五、Detect the extrusion tightness of the outer sheath: the outer sheath of high-quality coaxial cables is wrapped tightly, which can reduce the inner gap of the shielding layer, prevent air from entering to cause oxidation, and prevent the relative sliding of the shielding layer from causing the drift of electrical properties , but if the package is too tight, it will cause inconvenience in stripping and increase the difficulty of construction. The inspection method is to take a 1m long cable and strip off the sheath at the end, so that the core cannot be pulled out with force.

六、Observe the shape of the cable loop: the cable loop is not only reflected in the appearance of the cable, but more importantly, the quality of the cable. The cables are formed flat and flat, each cable is kept on the same concentric plane, and the cables are in parallel contact with each other in a circular arc, which can reduce the mutual force between the cables, and the stacking is not easy to deform and damage, so it is not necessary when checking the quality of the cables. If you are careless, just take a look, and observe carefully.

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