RG-6

RG was originally a unit indicator [1] for bulk radio frequency (RF) cable in the U.S. military's Joint Electronics Type Designation System.

The RG unit indicator is no longer part of the JETDS system (MIL-STD-196E) and cable sold today under the RG-6 label is unlikely to meet military specifications.

In practice, the term RG-6 is generally used to refer to coaxial cables with an 18 AWG (1.024 mm) center conductor and 75 ohm characteristic impedance.

75 ohm cables are also used in professional video applications, carrying either base band analog video signals or serial digital interface (SDI) signals; in these applications, the center conductor is ordinarily solid copper, the shielding is much heavier (typically aluminum foil, and 95% copper braid), and tolerances are more tightly controlled, to improve impedance stability.

"Flooded" cable is infused with water blocking gel for use in underground conduit or direct burial.