The shield of Coaxial cable
There is also a lot of variety in the shield. Conventional coaxial cable has braided copper wire forming the shield. This allows the cable to be flexible, but it also means there are gaps in the shield layer. It also means the inner dimension of the shield varies slightly because the braid cannot be flat. Sometimes the braid is silver plated. For better shield performance, some cables have a double-layer shield. The shield might be just two braids, but it is more common now to have a thin foil shield covered by a wire braid. Some cables may invest in more than two shield layers. Other shield designs sacrifice flexibility for better performance; some shields are a solid metal tube. Those cables cannot take sharp bends, as the shield will kink, causing losses in the cable. Many Cable television (CATV) distribution systems use such cables, as they provide a lower signal loss.
The insulating jacket can be made from many materials. A common choice is PVC, but some applications may require fire-resistant materials. Outdoor applications may require the jacket to resist ultraviolet light and oxidation. For internal chassis connections the insulating jacket may be omitted.
Connections to the ends of coaxial cables are usually made with RF connectors.

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