Coaxial (or “coax”) cable is a common type of cable used for transmitting data over long distances. It can carry either an analog or digital signal. While coax cables have many applications, they are most commonly used to transmit cable TV and Internet signals.
Coax cables that run underground are typically thicker and more heavily insulated than the cables that connect your cable box or cable modem to the wall outlet. However, they all transmit data via a thin copper line in the middle of the cable. This wire is surrounded by a layer of insulation comprised of non-conductive or “dielectric” material. The dielectric layer is covered with one or more metallic shields that provides additional protection from signal interference. Finally, a protective plastic outer layer surrounds the entire cable.
The heavy duty design of coaxial cables is what allows them to carry data over long distances with minimum signal degradation. In many cases, coax cables laid by cable companies several decades ago are sufficient to provide HDTV and high-speed Internet access simultaneously. However, certain coax cables (such as RG-59 cables) are designed for low bandwidth applications, like connecting a VCR to a TV, and may not provide enough bandwidth to carry a full HDTV signal. Coax cables labeled as “RG-6” are a better choice for HDTV and cable Internet service.