RG58

RG-58 is a 50-ohm coaxial cable widely used for RF transmission. It is part of the RG-series designation used in the mid-20th century to categorize coaxial cables for radio equipment. The most common variant is RG-58/U. A typical RG-58 assembly consists of a central copper conductor, a dielectric insulating layer (commonly polyethylene or PTFE), an outer shield of braided copper (and sometimes foil), and a color-coated outer jacket—usually PVC. Its nominal impedance is 50 ohms, chosen to match many transmitters, receivers, and test instruments.

It is used for short- to medium-length RF links, including VHF and UHF applications, antenna feeds, and laboratory bench setups. The cable is inexpensive, flexible, and widely available, which has contributed to its enduring popularity in hobbyist and professional settings alike. Variants differ mainly in dielectric material and jacket construction, which in turn influence attenuation, losses, and flexibility; some RG-58 cables use foam dielectric for lower capacitance, while others use solid media for ruggedness.

Performance notes: while suitable for many standard RF tasks, RG-58 exhibits higher loss than many modern low-loss coax when run over long distances or at higher frequencies. It is generally not recommended for long-run high-frequency links or high-power applications where efficiency is critical. As with other coaxial cables, impedance matching, connectors, and weathering can affect performance.

Common related terms: 50-ohm systems, coaxial cable, amateur radio.