A twisted pair can be used as a balanced line, which as part of a balanced circuit can greatly reduce the effect of noise currents induced on the line by coupling of electric or magneti… See more

The earliest telephones used telegraph lines which were single-wire earth return circuits. In … See more

Unshielded twisted pair (UTP) cables are found in many Ethernet networks and telephone systems. For indoor telephone applications, UTP is often grouped into sets of 25 pairs … See more

Twisted pair cables may incorporate shieldingin an attempt to prevent electromagnetic interference. Shielding provides an electrically conductive barrier to attenuat… See more

Analog telephone
Before digital communication and Ethernet became widespread there was no international standard for telephone cable. Standards … See more