What are RG63 Coaxial Cables?

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- everything RF

Jan 16, 2023

RG63 Coaxial Cables are a type of cable that is ideal for high frequency signal transmission. It exhibits excellent signal integrity and features low signal loss, making it suitable for long-haul communication links and telecommunication applications.


The RG-63/A/B/U is a 125-ohm coaxial cable with an overall diameter of 0.405 inches and a voltage rating of up to 1000 Vrms. It has an inner copper weld wire (CW) or copper-clad steel (CCS) conductor (carrying the electrical signal), which is enclosed by an insulation layer typically made of air space Polyethylene (ASP). The insulation layer is then completely enclosed by 1 bare copper braid shield that forms the outer conductor and also provides shielding against electromagnetic interference (EMI). Finally, the structure is covered with an outermost layer - called a jacket - made of Polyvinyl Chloride (PVC). The jacket protects the cable core from mechanical, moisture, and chemical issues.

The RG-63/A/B/U cable exhibits capacitance of approximately 10.0 pF/ft (32.89 pF/m), signal attenuation of around 5.5 dB/100 ft at 400 MHz (signal attenuation of the cable depends on the frequency) and has a velocity of propagation of 84%. It has a center conductor measuring 0.0253 inches (0.643 mm) in diameter and an insulation layer measuring 0.283 inches (7.2 mm) in diameter.

Key Specifications of RG-63/A/B/U Coaxial Cables


Typical Value

Overall Diameter (inch)


Characteristic Impedance (Zo)

125 ohms

Maximum Voltage Rating (RMS)

1000 V

Cable Capacitance (pF/ft)


Attenuation (dB/100 ft, @ 400 MHz)



Air space Polyethylene (ASP)

Click here to view a list of coaxial cables on everything RF.