Coax Cable Sizes & Uses

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Coaxial cables are used for transmitting signals for cable television, Internet, radio and telephone applications. You will recognise these cables as the thick black wires with a copper wire sticking out the end of it.

Coaxial cables consist of an outer PVC sheath that protects the cable, a dialectric insulating layer and a copper wire conductor in the middle. There are several different sizes and uses for coaxial, or coax, cables. Here are some of the most commonly used cables.


RG-11 is one of the common types of coax cable. This type of cable is used to extend long distances, particularly for underground conduits and long drops. The diameter of the insulation is 7.24mm and the outside diameter is 10.3mm. This is a thick cable that is not easily bend or destroyed. The copper wire inside acts as the conductor. RG-11 has a 75-ohm capability and a maximum operating voltage of 5,000.


RG-6 wire is often used for cable television and satellite applications. The outer diameter is 6.9mm and the dielectric layer is 4.6mm. There is a copper wire in this coax wire, as well as an aluminium polyester foil that encases a tin and copper braid. The maximum operating voltage for RG-6 is 2,700 with a 75-ohm impedance.


RG-59 is a thinner coax cable with a 3.7mm dialectic layer and an outside diameter of 6.15mm. These are not as readily used as much anymore but years ago they were used for often for cable systems and closed circuit televisions, specifically when there was an A and B switch between television channels. RG-59 has a 75-ohm impedance and a maximum 2,300 voltage.


RG-60 is often used with high definition cable television and for high speed Internet connections. The outside diameter is 10.8mm and a 1.024 core diameter. RG-60 has an impedance of 50 ohms.


RG-58 is used for radio communication, thin ethernet and NIM electronics. This is considered a general purpose coax cable. This cable has an inner diameter of 2.95 and an outside diameter of 4.95.