How to detect the quality of RF coaxial cables

The quality of RF coaxial cables is a direct factor affecting the stability and loss of signal transmission. A high-quality RF coaxial cable has a very round cross-section, and the outer shielding layer and aluminum foil of the cable are attached to the outer surface of the insulating medium. Usually, the surface of the medium is round and the performance is better. Today, the editor will take you to understand how to detect the quality of RF coaxial cables.

1、 Observe the roundness of the insulating medium

The standard RF coaxial cable has a very round cross-section, with the outer shield of the cable and aluminum foil attached to the outer surface of the insulating medium. The more round the outer surface of the medium, the smaller the gap between the aluminum foil and its outer surface, and the larger the gap if it is not round. And it has been proven through practice that the smaller the gap, the better the performance of the cable. In addition, air with large gaps is prone to invade the shielding layer, leading to a decrease in the service life of the cable.

2、 Check the consistency of the insulation medium of coaxial cables

The diameter fluctuation of coaxial cable insulation medium mainly affects the echo coefficient of the cable. This inspection can cut out the insulation medium of a section of the cable, and carefully check the outer diameter of each point with a micrometer to see if it is consistent.

3、 Check the quality of aluminum foil

Aluminum foil plays an important shielding role in coaxial cables, which can avoid external open circuit signal interference and prevent cable TV signal leakage. Therefore, the quality of aluminum foil should be tested for new coaxial cables. Firstly, cut open the protective layer and observe whether the surface of the braided wire and aluminum foil layer maintains good gloss; Next, take a section of cable and wrap it tightly around a metal shaft. Straighten and twist it in the opposite direction, repeat several times, and then cut open the cable sheath layer to observe if there is any cracking in the aluminum foil. Alternatively, you can cut a small section of aluminum foil and rub and stretch it repeatedly in your hand. If it still does not break after multiple rubs and stretches, it is better to have a certain degree of toughness. Otherwise, the quality is considered defective.

4、 Check the coaxial cable braided mesh

The braided mesh of coaxial cable plays an important role in the shielding performance of coaxial cable, and whether it is in centralized power supply cable TV lines or power supply circuit lines, the quality inspection of coaxial cable must carefully observe whether the woven mesh is tight and flat. The method is to cut open the outer sheath of coaxial cable, cut a small section of coaxial cable braided mesh, and identify the quantity of braided mesh. If it matches the given index value, it is qualified. In addition, a single woven mesh is measured with a spiral micrometer. Compared at the same price, the thicker the wire diameter, the better the quality.

5、Check the compression tightness of the outer protective layer

The outer protective layer of high-quality coaxial cables is tightly wrapped, which can reduce the gap inside the shielding layer, prevent air from entering and causing oxidation, and prevent the relative sliding of the shielding layer from causing electrical performance drift. However, if the packaging is too tight, it will cause inconvenience in stripping the head and increase the difficulty of construction. The inspection method is to take a 1m long cable and strip off the protective layer at the end, so that the core cannot be pulled out with force.

6、 Observe the cable forming a circular shape

The formation of cable loops is not only reflected in their aesthetic appearance, but more importantly, in the quality of the cables. The cables are formed in a flat circle, and each cable is kept on the same concentric plane. The cables are in contact with each other in a circular arc parallel to each other, which can reduce the mutual force between cables and prevent deformation and damage when stacked. Therefore, when inspecting the quality of cables, do not be careless and take a rough look, but observe carefully.

Tag # RF Coaxial Cable Quality Inspection # RF Coaxial Cable Function#