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 outer surface. , the less rounded the gap will be. Practice has proved that the smaller the gap, the better the performance of the cable. In addition, the air in the large gap easily invades the shielding layer and affects the service life of the cable.
2. Detect the consistency of the insulating medium of the coaxial cable. The fluctuation of the diameter of the insulating medium of the coaxial cable mainly affects the echo coefficient of the cable. This inspection can cut out the insulating medium of a section of the cable, and carefully check the outer diameter of each point with a micrometer. Is it consistent.
3. Detect the braided mesh of the coaxial cable, and check whether the braided mesh is tight and flat. The method is to cut the outer sheath of the coaxial cable, cut a small section of the braided mesh of the coaxial cable, and identify the number of the braided mesh. Values that match are qualified. In addition, a single braided wire is measured with a spiral micrometer. Under the same price, the thicker the wire diameter, the better the quality.
4. Check the quality of the aluminum foil. The aluminum foil plays an important shielding role in the coaxial cable. It plays an important role in preventing external open-circuit signal interference and cable TV signal leakage. Therefore, the quality of the aluminum foil should be checked for new coaxial cables. Cut the sheath layer and observe whether the surface of the braided wire and the aluminum foil layer maintains a good luster; then take a piece of cable, wrap it tightly around the metal small shaft, straighten it and turn it in the opposite direction, repeat several times, and then cut the cable sheath Check whether the aluminum foil is cracked or not. You can also cut out a small section of aluminum foil and repeatedly rub and stretch it in your hand. After repeated rubbing and stretching, it still does not break, and the one with certain toughness is qualified.
5. Check the extrusion tightness of the outer sheath. The outer sheath of the high-quality coaxial cable is tightly wrapped, which can reduce the gap in the shielding layer, prevent the air from entering and cause oxidation, and prevent the relative sliding of the shielding layer from causing electrical performance. Drift, but extrusion too tight will cause the sheath to be peeled off, so it is appropriate that the core cannot be pulled out with force.
6. Observe the shape of the cable loop. The cable loop is not only an aesthetic problem, but also a quality problem. The cables are formed into a circle and flat, each cable is kept on the same concentric plane, and the cables are in arc-parallel contact with each other as a whole, which can reduce the mutual force of the cables, and is not easy to be deformed and damaged when stacked.
