What are RG111 Coaxial Cables?

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- everything RF

Jan 17, 2023

RG111 Coaxial Cables are a type of cable that forms an essential component in many electronic and networking systems applications. They provide an excellent signal integrity and low signal loss, making them suitable for long-haul communication links. A high degree of durability and flexible design makes them ideal for both indoor and outdoor scenarios.


The RG-111/A/U is a 95-ohm coaxial cable with an overall diameter of 0.478 inches and a voltage rating of up to 1000 Vrms. It has two inner bare copper wires (carrying the electrical signal) with 7-stranding construction. The inner conductors are enclosed by an insulation layer made of Polyethylene (PE). The insulation layer is then completely enclosed by 2 tinned copper braid shields that form the outer conductor and also provide shielding against electromagnetic interference (EMI). The shield layer is then covered by a layer- called a jacket - made of Polyvinyl Chloride (PVC). The jacket protects the cable core from mechanical, moisture, and chemical issues. Finally, the structure is covered with an outermost layer-called armor. The armor is made of an aluminum braid and offers extra mechanical protection to the cable. 

The RG111/A/U cable exhibits capacitance of approximately 16 pF/ft (52.63 pF/m), and signal attenuation of around 10.5 dB/100 ft at 400 MHz (signal attenuation of the cable depending on the frequency). It has a center conductor measuring 0.0456 inches (1.158 mm) in diameter and an insulation layer measuring 0.285 inches (7.2 mm) in diameter.

Key Specifications of RG-111/A/U Coaxial Cables


Typical Value

Overall Diameter (inch)


Characteristic Impedance (Zo)

95 ohms

Maximum Voltage Rating (RMS)

1000 V

Cable Capacitance (pF/ft)


Attenuation (dB/100 ft, @ 400 MHz)



Polyethylene (PE)

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