1. Observe the roundness of the insulating medium. The cross section of the standard coaxial cable is very round. The outer conductor of the cable and the aluminum foil are 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 surface. , The less round the gap, the larger the gap. Practice has proved that the smaller the gap, the better the performance of the cable. In addition, the large gap air easily penetrates into the shielding layer and affects the service life of the cable.
2. Detect the consistency of the insulation medium of the coaxial cable. The diameter fluctuation 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. Carefully check the outer diameter of each point with a micrometer to see its Are they consistent?
3. Testing the coaxial cable braided network. The coaxial cable's shielding performance plays an important role in the braided network cable of the coaxial cable, and there is also a power supply return line in the power cable TV line. Therefore, the coaxial cable quality inspection It is necessary to check whether the braided mesh is tight and flat. The method is to cut the outer sheath of the coaxial cable, cut a short section of the braided mesh of the coaxial cable, and evaluate the quantity of the braided mesh. If the index value is small, it is unqualified. In addition, a single micro braided network cable is measured with a spiral micrometer. At the same price, the thicker the wire diameter, the better the quality.
4. Check the quality of aluminum foil. Aluminum foil plays an important role in shielding coaxial cables. It plays an important role in preventing external open-circuit interference and cable TV signal leakage. Therefore, the quality of aluminum foil should be checked for new coaxial cables. Cut the sheath layer and observe whether the surface of the braided network cable and the aluminum foil layer maintains good gloss. Then take a section of cable and wind it tightly on the small metal shaft, straighten it and twist it in the opposite direction, repeat it several times, and then cut the cable sheath. Check the aluminum foil for cracks, and cut out a small section of aluminum foil repeatedly rubbed and stretched in your hands. After repeated rubbing and stretching, the aluminum foil is not broken. If it has a certain toughness, it is qualified, otherwise it is defective.
5. Check the tightness of the outer sheath. The outer sheath of high-quality coaxial cables is tightly packed. This can reduce the gap in the shield layer, prevent air from entering and causing oxidation, and prevent the relative sliding of the shield layer from causing electrical performance. Drifting, but squeezing the package too tightly will cause the protective layer to peel off, and it is appropriate that the core cannot be pulled out by force.
6. Observe the shape of the loop of the cable. The loop of the cable is not only an aesthetic issue, but also a quality issue. The cables are flat and looped, and each cable is kept on the same concentric plane. The cables and the cables form a circular arc in parallel and overall contact, which can reduce the mutual stress of the cables, and it is not easy to be deformed and damaged during stacking.