Why Are Telephone Cables Pressurized?
The biggest threat to telephone wires (conductor pairs) is moisture. Many of the copper cables use paper or pulp as insulation between the individual conductor pairs. This type of cable offers excellent insulation characteristics as long as it is maintained dry. Pulp insulation has been around for a long time, and for many years it had essentially no competition. Eventually plastic insulated conductor (PIC) cable encroached upon its popularity and took over the number-one spot. <<More>>