Coaxial Cable and Wire Key Terms

Bone up on electrical terminology with these coaxial cable and wire key terms

By Mark Jenkins

Coaxial cables have become a staple of the telecommunications and entertainment industries. From cable television to digital surround sound, all sorts of electronic media rely on coaxial cables for smooth, clear transmission of video, audio and radio broadcasts. Although they've been around since the 1920s and are undoubtedly popular, coaxial cables remain a viable option in the telecommunications industry. Coaxial cables use a number of different components. To understand how they work, you may want to learn coaxial cable and wire key terms.

Sweep testing

Sweep testing is the process of checking high-quality coaxial cables for efficiency and clarity. This advanced procedure allows manufacturers to make sure their cables produce clear signals across a wide range of frequencies.
Try: Earthcom explains the basics of sweep testing. To see examples of sweep-tested cables, visit TigerDirect.

Dielectric

In simple terms, a dielectric is an insulator. In coaxial cables, dielectrics surround the conductive center wiring to keep the electrical signal from bleeding out to other surfaces.
Try: The Physics Hypertextbook has a great explanation of dielectrics in its online database.

RF

Short for radio frequency, RF describes a range of signal frequencies from 3Hz to 300GHz. Coaxial cables often prove to be among the best cables for carrying RF transmissions, such as television broadcasts.
Try: To learn why coaxial cables work so well for RF transmissions, read the article from Electronic Design.

Connector

Coaxial cables come with different types of connectors. Depending on what kinds of signals manufacturers designed them to carry, the connectors may have different electrical resistances, frequency ranges and shapes.
Try: Get more information about coaxial connectors from ePanorama.net, which has developed an in-depth guide to the technology.

Impedance

As a signal flows through a cable, impedance slows it down. Impedance is a kind of electrical resistance, measured in ohms. Coaxial cables typically have impedances of either 50 or 75 ohms, but other ratings are possible.
Try: There's an explanation of impedance in layman's terms at eCoustics.com.

Shielding

The shielding is the second conductive element of a coaxial cable, along with the core. Manufactures use either foil or braided metal to make the shielding. The shield's main role is to act as a ground for the main signal, but it also protects against electromagnetic interference (EMI), which can degrade video and audio quality.
Try: Get a basic understanding of shielding by reading Pelco's guide to coaxial cable structure.