Coaxial Cable Expert Guide: Structure, Types, and How to Install

What is Coaxial Cables?

A coaxial cable is an electrical cable used in the transmission of signals, including high-frequency radio waves and data. The coaxial cables are quite common in applications such as cable television, satellite TV, networking, commercial radio transmission, and audio/video systems. These cables are commonly used for such applications because of their signal stability.

The Structure of Coaxial Cables and How They Work

The construction of coaxial cables determines their performance. Their structure includes the inner conductor, insulating layer, outer shield, and outer jacket.

The inner conductor is a solid or stranded wire, mostly made of copper material. Its job is to carry the electrical signal from one device to another.

The insulating layer follows the inner conductor. It is often made of materials such as PVC or PTFE. The insulator separates the inner conductor from the outer shield and prevents signal leakage.

The outer shield is made of braided or foil wrapping around the insulator. This material is vital to prevent electromagnetic interference (EMI) and ensure better signal stability.

The outer jacket forms a protective layer around the other components of the coaxial cable. It is usually made of PVC or a durable material that can withstand all the elements.

Types of Coaxial Cables

Coaxial cables can be categorized based on impedance, flexibility, and the type of application. Let us look at each category.

By Impedance

You will come across the 75-ohm and 50-ohm coaxial cables. The 75-ohm coaxial cable is primarily used for video signals. Examples include those used for cable TV and satellite systems.

As for the 50-ohm cables, they are used for wireless communication and data transfer.

By Flexibility

You will encounter flexible, semi-rigid, rigid, and formable coaxial cables. Flexible coaxial cables have a robust outer shield but are still flexible. They are commonly used for common applications, including cable TV.

The semi-rigid cable offers a good balance between rigidity and flexibility. It is expected to be used in applications that need more structural support than flexible coaxial cable offers.

Rigid coaxial cables have a rigid outer conductor. This is vital for providing stability for applications with high-frequency performance.

Formable coaxial cables are built to be bent and formed into different shapes depending on the installation space. This allows for the ease of installing the cables in tight spaces.

By Application

If you come across a coaxial cable with the label RG-6, then know it is meant for satellite and cable TV installations. The RG-6 coaxial cable is a common cable type for commercial and residential settings.

The RG-11 coaxial cable is thicker than the RG-6 cable. Being thicker also means it offers better signal retention, which will be useful for long-distance cable runs and high-frequency transmissions.

Twinaxial and triaxial coaxial cables have two and three inner conductors, respectively. These conductors are separated by dielectrics and shielding. These are mostly special-purpose cables for unique applications.

Types of Coaxial Cable Connectors

The coaxial cable connectors are vital for ensuring a reliable and secure connection. Expect to come across many options when looking for coaxial cable connectors, but we will mention a few commonly used in many applications.

BNC Connector or Bayonet Neill-Concelman Connector

This connector has a quick connect and disconnect feature. Its use of the bayonet locking mechanism ensures a secure connection. These connectors are common in test equipment, instrumentation, and video applications.

TNC or Threaded Neill-Concelman Connector

These are small, weatherproof connectors designed to operate up to 12GHz. They are commonly used for mobile phones and antenna connections. The distinctive feature is the threaded coupling mechanism, which assures the user of a robust and secure connection.

N-Type Connectors

N-type connectors are designed for applications that require high-frequency signals. They can handle signals up to 18GHz quite well without an issue, which is why they will be good for commercial applications.

SMA Connectors

The SMA connectors are miniature threaded coaxial connectors vital for applications with limited space. They handle high-frequency applications quite well.

SMB Connectors

These are similar to SMB connectors, but they have a lower profile. They offer a smaller footprint while maintaining impressive performance of up to 5GHz.

F-Type Connectors

F-type connectors are commonly used for satellite television, cable television, and cable modem applications. They offer impressive signal stability, which is essential for their success.

Advantages of Coaxial Cables

When you get to start using coaxial cables, you will understand why they are still popular today. Here are the expected advantages of using coaxial cables.

High Bandwidth

Coaxial cables are known for their capability to support high bandwidth, which means they can transmit large amounts of signals and data. That is why companies still use these cables for cable TV and high-speed internet connections.

Resistance to Interference

The construction of the coaxial cable makes it easy to protect the signal from interference. The cable comes with a metal shield that protects the signal from electromagnetic interference, ensuring a reliable signal transmission.

Long Cable Lengths

Compared to other types of cables, coaxial cables can support applications that require long cable lengths. Even when the cable is long, it does not affect the overall signal strength.

Easy Installation

These cables are easy to install and handle. Their construction allows for flexibility, so even in places with tight spaces, the cable can be bent to fit the application.

Versatile Applications

Coaxial cables are generally suitable for a wide range of applications. Whether it’s analog or digital data transmission, they will handle it. They are also suitable for internet connections, cable TV, and more.

Durable and Rugged

Coaxial cables are known for their durability and ruggedness. Therefore, they should be able to be used for both indoor and outdoor installations.

Impressive Resistance to EMI

The metallic shield of the coaxial cable effectively prevents electromagnetic interference. This is crucial for ensuring reliable signal transmission at all times, especially in an area with a lot of interference.

Common Applications of Coaxial Cables

• Cable TV and satellite TV
• Wireless communications
• Broadband internet
• Medical equipment such as MRI machines
• Computer and instrumentation data transmission
• Automobiles, military, and aircraft

Limitations of Coaxial Cables

As much as coaxial cables have many advantages, they also have some limitations worth checking out. Such include:

Radio Frequency Interference (RFI)

As much as coaxial cables are stable against EMI, they can still be vulnerable to RFI. This disrupts signal transmission and may lead to signal leakage. Such vulnerability makes it a security concern as the cables are prone to eavesdropping.

Limited Bandwidth

Compared to fiber optic cables, coaxial cables have limited bandwidth. This means you may be limited in the amount of data you can transfer over the coaxial cable.

Signal Loss

As much as the coaxial cable can maintain good signal strength, distance can affect this. In this case, you need to use amplifiers to boost the signal until it gets to its destination.

Bulky

Coaxial cables are generally bulky because of their size. When compared to fiber optic cable, you can see how it might be better to opt for alternatives if you need to save on space and get something more flexible.

How to Choose Coaxial Cables

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Understand Your Needs

Having a good understanding of where you will be using the cable determines whether you would choose it or not. Common applications include using the cable for TV, internet, satellite, and CCTV. Once you understand this, you can choose the right coaxial cable.

Choose Based on Cable Type

The right cable type will help you determine the proper use of the cable. For example, if you want to use the cable for high bandwidth applications, then choose the RG-6 coaxial cable. How about for applications where you need to pass the cable through tight spaces? In such a case, consider the flexible coaxial cable.

Cost and Quality

Look at the overall quality of the coaxial cable. This determines its durability. Quality is vital, especially if you use it in harsh outdoor conditions.

How about the cost? Look for a product that gives you a balance between the price and features of the coaxial cable. Different brands offer varying prices for their products. So, choose accordingly to find the best coaxial cable for the money.

Other Key Factors

The impedance of the cable will be indicated on it. There are applications that work well with 75-ohm cables, while others need 50-ohm cables.

Consider shielding as well. Make sure you use a cable with impressive shielding, which should provide better signal strength and durability.

Weatherproofing is another good feature a manufacturer should include. Look to see if the cable comes with weatherproofing features so that it can be used outdoors.

How to Install A Coaxial Cable

Installing a coaxial cable requires you to have the right connector for the job. Here is how you would proceed to install the cable.

• Prepare the cable by stripping the outer jacket. You can use a coax cable stripper or a utility knife. Be careful not to damage the inner conductor.
• Let us say you are using the F-type connector. Simply insert the inner core into the connector. Make sure it is well aligned and that a good portion of the inner core is inside the connector.
• Use a compression crimper to crimp the F-type connector onto the cable. This is crucial for a secure connection.
• Route the cable in tubes or use cable clips to get the cable to its destination.
• For termination, use the same method we used above to attach a connector and secure the cable in position.
• Go ahead to test it and see if the cable is working correctly.

Coaxial Cable Alternatives

After reading about the limitations of coaxial cables, you may feel that alternatives will do a better job. So, what are the alternatives? The most common options are twisted-pair Ethernet cables and optical fiber cables.

Twisted pair Ethernet cables offer higher speeds and better performance than coaxial cables. The common types include Cat5e, Cat6, and Cat8 cables. The Cat8 cable offers the highest speed and bandwidth.

Twisted-pair Ethernet cables can transmit both data and video signals. They are most often used for data transmissions in internet connectivity.

Optical fiber cables are also better in terms of speed and bandwidth. Instead of having a conductor, these cables use light to transmit the data, enabling amazing speeds.

Optical fiber cables are suitable for long-distance communications and applications with high bandwidth needs. That is why they are replacing coaxial cables in applications such as internet access by providers.

You can still consider wireless technologies such as Wi-Fi for data transmission using radio waves. This eliminates the need for physical cables.

Conclusion

Coaxial cables remain good options for those who need to connect to satellite TV, cable TV, and other applications. Undoubtedly, you will always come across applications where coaxial cables are necessary and still deliver good performance. It is advisable to use the right coaxial cable connector as well. It helps in giving a good connection that ensures the best performance, too. With good installation practices, the coaxial cable should last quite a long time.