[U]

UHF - abbreviation for ultra high frequency, 300 to 3,000 Mhz.

UL - Underwriters Laboratories. A nonprofit organization which tests and verifies construction and performance of electronic parts and equipment, including wire and cable.

Unbalanced Circuit - a transmission line in which voltages on the two conductors are unequal with respect to ground; e.g., a coaxial cable

Unidirectional Concentric Stranding - a stranding where each successive layer has a different lay length, thereby retaining a circular from without migration of strands from one layer to another

Unilay - more than one layer of helically laid wires with the direction of lay and length of lay the same for all layers.