Coaxial cables, often referred to as coax cables, are a common type of electrical cable that are widely used for transmitting various signals, such as television, internet, and radio. Coaxial cables have a unique construction that makes them well-suited for carrying high-frequency signals with minimal interference.
What is a Coaxial Cable?
A coaxial cable is a type of electrical cable consisting of a central conductor, an insulating layer, a metallic shield, and an outer insulating layer called a jacket. This construction provides protection against electromagnetic interference and allows for the efficient transmission of high-frequency signals. The name ‘coaxial’ refers to the inner conductor and outer shield sharing one geometric axis.
Components of a Coaxial Cable
Coaxial cables typically contain the following parts. Inside is a central conductor which carries the electrical signal. Central conductors in coaxial cables are usually made of copper, aluminium or copper covered steel. Around that is an insulating layer (called a dielectric). The coaxial cable dielectric separates the central conductor from the outer layers, preventing electrical contact. Coaxial cables also contain a metallic shield that protects the signal from external interference and electromagnetic radiation. Lastly, an outer insulating sheath or jacket provides additional insulation and protection.
Some coaxial cables may contain more than one metallic shield or braid, depending upon the application they are designed for.
Common Coaxial Cable Applications
Coaxial cables are the backbone of cable television systems, delivering a variety of signals to homes and businesses. Satellite TV providers use high-quality coaxial cables to transmit digital signals from satellites to subscribers' satellite dishes. Coaxial cables are used to connect antennas to radios and other communication equipment for transmitting and receiving radio signals.
Many internet service providers (ISPs) have also used coaxial cables to deliver high-speed internet access to homes. This is known as "cable internet."
Coaxial cables also have security applications too, usually for video transmission in CCTV surveillance systems.
Common Types of Coaxial Cables
WF100, WCF100, HD100, CT100, RG6
Suitable for high-frequency signals, and commonly used in residential installations, particularly for cable television (CATV), satellite TV, and broadband internet. WF100 and other 100 type coaxial cables provide good signal quality over long distances.
WF125, RG7
These cable types can also be used for CATV and satellite TV. They are thicker and provides less signal loss over extended distances, making them ideal for longer cable runs.
WF165, RG11
Used for longer cable runs in CATV and satellite TV, they are thicker than the WF100 and WF125 cable types, providing less signal loss over extended distances, making them suitable for much larger buildings and commercial installations.
RG59
RG59 coaxial cable is often found in CCTV applications and analogue cable television. RG59 has a thinner central conductor and is suitable for lower-frequency applications. It can also be a cost-effective cable for shorter cable runs.
RG8, RG213
Usually found in amateur radio and some data transmission applications, RG8 and RG213 are larger coaxial cables with thicker central conductors. They are used in more demanding applications, providing better signal transmission.
More Specialized Coaxial Cables
RG58
RG58 coaxial cable is commonly used in radio frequency connections and some ethernet applications. It is a smaller and more flexible cable, suitable for short-distance applications. It can also be more cost-effective for basic connectivity needs.
RG174
RG174 coaxial cables are used in radio frequency and small-scale applications. They are again thin and flexible, and ideal for use in tight spaces.
High Temperature/High Performance Coaxial Cables
Suitable for more demanding environments, including applications in industry and engineering, high performance and high temperature coaxial cables use PTFE and FEP materials in their construction. They have excellent temperature resistance from -65°C to 200°C, and the outer sheath offers exceptional oil, chemical, as well as UV protection. Examples include RG178, RG179, RG316, and RG400.
Land Mobile Radio Cables
Sometimes referred to as LMR or WEB cables, these cables are used in two-way communications systems, as well as in VSAT mobile phone and satellite communication applications, usually in maritime environments. They are flexible and durable, and designed to provide mobile communication systems in more challenging environments. Ultimately though, they can be used in any application that requires a flexible coaxial cable that’s easy to route.
URM Coaxial Cables
Uni Radio-Metric (URM) coaxial cables cover many different high frequency data and signal transmission applications. In some CCTV applications that require the cameras to move, URM70 can be a better choice than RG59, as its stranded conductor is less prone to breaking than the solid conductor in an RG59 cable.
Choosing the Right Coaxial Cable
Frequency and Bandwidth
Choose a cable that supports the frequency and bandwidth requirements of your specific application.
Signal Loss
Consider the length of the cable run and choose a cable with minimal signal loss for longer distances.
Cable Thickness
Thicker cables generally have lower signal loss over distance but may be less flexible. Consider the space and flexibility requirements of your installation.
Coaxial Cable Installation
Poorly installed coaxial cable is unlikely to meet the required performance levels, but there are a number of things that can be done to increase the chances of a successful installation.
Plan the Route
Determine the best path for cable runs, considering signal quality, distance, and potential sources of interference.
Cut and Prepare
Use cable cutters and strippers to prepare the cable ends. Strip the outer insulation, foil shield, and inner insulation, leaving a small, exposed section of the central conductor.
Connectors
Attach the appropriate connectors to the cable ends, ensuring a secure and proper fit.
Grounding
Ground the cable system as required to prevent electrical surges and static buildup.
Coaxial Cable Connectors
There are many different coaxial cable types, but many more connector types! Common coaxial cable connectors include F-type connectors and BNC connectors, with a few different installation methods too, including self-install, compression and crimp. Match the correct connector type to the correct equipment and ensure they are properly tightened for good signal transmission.
Troubleshooting Common Issues
Signal Loss
Check for damaged cables, loose connectors, and interference sources. Replace damaged components and secure connectors.
Poor Picture Quality
Ensure cables are correctly connected and in good condition. Consider upgrading to a higher-quality coaxial cable if needed.
Electromagnetic Interference (EMI)
Identify and eliminate sources of EMI, such as fluorescent lights, radios, or other electronic devices.
Coaxial cables are a versatile and reliable choice for transmitting various signals over long distances. Whether for AV applications, connecting to the internet, satellite communications, or establishing a security system, understanding the basics of coaxial cables and their applications is crucial for successful installation and maintenance. With proper planning and care, coaxial cables can provide excellent signal quality and performance in many different applications.
Unsure which cable you need from our coaxial cable range? Get in touch or call 0115 972 4483 for expert assistance.
