Understanding Coaxial Cables: A Comprehensive Guide

By: Jeremy Neisser

What is Coaxial Cable?

Coaxial cable is an electrical transmission line that is used to transmit high-frequency signals with low signal loss. It has a wide range of applications, including phone lines, cable TV, internet, and cell boosters. Coaxial cables come in different sizes and lengths, each designed for specific uses.

What Does A Coaxial Cable Look Like?

A coaxial cable consists of four main parts: the center conductor/core, dielectric insulator, shield(s), and jacket. The core is a single copper or copper-coated steel wire that carries RF signals. The dielectric insulator surrounds the wire and maintains a constant distance between the center conductor and the next layer.

The metal shield, made of woven copper, aluminum, or other metals, wraps around the insulator to cancel out outside electromagnetic interference. Some coaxial cables have multiple shields for extra protection. The final layer is a jacket that protects the entire configuration. The jacket's rating indicates where the cable can be installed.

Coaxial cables used outdoors require extra insulation and special jackets to protect the wires from sun and moisture. The image above provides a visual representation of the four main parts of a coaxial cable.

How Do Coaxial Cables Work?

Coaxial cables are designed to transmit signals through the center wire. The signal travels through the wire and is protected by a metal shield that surrounds it. The metal shield generates a magnetic field that helps to keep the signal intact and prevent it from bleeding out.

The metal shield also protects the signal from electromagnetic interference, allowing the cable to be placed near other electronic equipment without any issues. The distance between the core and shield must be consistent throughout the cable, which is achieved by the dielectric insulator. The insulator also prevents the two signals from coming into contact and canceling each other out.

To further protect the components, the cable is covered by an outer jacket. This jacket insulates and protects the cable from damage.

Coaxial cables are capable of carrying RF signals over long distances with little interference or loss. Once the signal reaches its destination, it can be converted into various forms such as images, audio, WiFi, or amplified cell reception depending on the application.

In summary, coaxial cables work by transmitting signals through a center wire that is protected by a metal shield and a dielectric insulator. The outer jacket provides further protection, allowing the cable to carry RF signals over long distances with little interference or loss.

What are the Uses and Applications of Coaxial Cables

Cable TV

Coaxial cables play an essential role in transmitting video and data from cable companies to your television. They also connect your television or digital converter box to a personal antenna. This is made possible by the cable's ability to carry high-frequency signals with low loss, making it ideal for transmitting video and data.

Signal Boosters

Cell phone signal boosters are devices that amplify weak outside cell signals to provide stronger signals inside your home, office, or vehicle. Coaxial cables are used to connect the three components of the device, which include an outdoor antenna, an amplifier, and an indoor antenna. The coaxial cable bypasses signal-blocking material, allowing for stronger signals.

Cable Internet (Copper-Based)

Coaxial cables are used in cable internet to provide speedy internet access to homes. Copper-based cables are piped into homes from cable service providers, and routers or cable modems connect to coax or Ethernet outlets to receive the signal. This allows for multiple devices to be wired to the router or connected via WiFi for fast internet access.

Ham Radio

Ham radio is a means of communication over airwaves that does not require internet or cell phone technology. Coaxial cables are used to connect the antenna to the radio, providing a stronger signal. This allows for communication over long distances, even in remote locations.

Basic RF Systems

Coaxial cables are used with any RF system to carry radio frequency signals. RF waves are generated when an alternating current goes through a conductive material. Coaxial cables are ideal for this application due to their ability to carry high-frequency signals with low loss.

Coaxial cables are essential for applications requiring radio frequency transmissions, and their uses and applications are diverse. From transmitting video and data for cable TV to providing speedy internet access, coaxial cables are a critical component of modern communication systems.

Are All Coax Cables the Same?

No, coaxial cables are not all the same. They come in different sizes, materials, and shielding, each suited for specific applications. It's important to choose the right coax cable for optimal signal transmission.

Coaxial Cable Types

RG Coax Cables

RG Coax Cables, or Radio Guide Coaxial Cables, were the original military specification for coaxial cables. The RG number refers to the cable's diameter, with higher RG numbers indicating a thinner central conductor and vice versa. Here are some of the most common types of RG Coax Cables:

RG-6/U

RG-6/U is a widely used coaxial cable that has an impedance of 75 Ohm. It is commonly used in residential and commercial applications, such as cable television and home internet. The core size is 1.024 mm, and the dielectric type is PF. The nominal attenuation per MHz is 850/8.5dB and 1900/13.6dB.

RG-8

RG-8 is similar to RG-6, but it has an impedance of 50 Ohm and is unable to carry pure video signals. It is commonly used in audio control rooms, radio stations, and external radio antennas. The core size is 2.17 mm, and the dielectric type is PF. The nominal attenuation per MHz is 850/6.4dB and 1900/10.4dB.

RG-11

RG-11 is a higher gauge cable used for CATV, HDTV, TV antennas, and video distribution. It has an impedance of 75 Ohm and covers up to 3 GHz. The core size is 1.67 mm, and the dielectric type is PF. The nominal attenuation per MHz is 850/6.25dB.

RG-59

RG-59 is a 75 Ohm coax cable that is best used for CCTV, audio video, and other low-frequency applications. It is flexible and easy to install, but it is not meant for long runs. The core size is 0.64 mm, and the dielectric type is PF. The nominal attenuation per MHz is N/A.

LMR® Coax Cable

LMR® Coax Cable is the newer generation of RF coaxial cables. It provides greater flexibility, ease of installation, and lower cost. LMR® number is a rough estimate of the cable's thickness. Here are some of the most common types of LMR® Coax Cable:

LMR®200

LMR®200 is an outdoor-rated flexible low loss communications coax that has a 50 Ohm impedance. It is great for short antenna feeder runs and features low-PIM. The core size is 1.12 mm, and the dielectric type is PF. The nominal attenuation per MHz is 850/9.6dB and 1900/14.6dB.

LMR®240

LMR®240 is also an outdoor-rated flexible low loss communications coax with a 50 Ohm impedance. It is designed for short feeder runs for applications like GPS, WLAN, and mobile antennas. The core size is 1.42 mm, and the dielectric type is PF. The nominal attenuation per MHz is 850/7.2dB and 1900/11.2dB.

LMR®400

LMR®400 is a flexible communications coax with a 50 Ohm impedance. It is used for jumper assemblies in wireless communications systems and antenna feeder runs. If you need a cable that requires periodic or repeated flexing, choose this one. LMR®400 was designed to replace the RG-8 cables. The core size is 2.74 mm, and the dielectric type is PF. The nominal attenuation per MHz is 850/3.8dB and 1900/5.8dB.

LMR®600

LMR®600, also known as "Half-Inch," is designed for outdoor use. It is more flexible than air-dielectric and hardline cables in terms of bending and handling. It also has a 50 Ohm impedance. The core size is 4.47 mm, and the dielectric type is PF. The nominal attenuation per MHz is 850/2.4dB and 1900/3.8dB.

LMR®900/1200/1700

LMR®900/1200/1700 are larger cables that are designed for medium antenna feeder runs with any application needing an easily routed, flexible low loss cable. The core size for LMR®900 is 6.65 mm, and the dielectric type is PF. The nominal attenuation per MHz is 850/1.6dB and 1900/2.6dB. The core size for LMR®1200 is 8.66 mm, and the nominal attenuation per MHz is 850/1.2dB and 1900/1.9dB. The core size for LMR®1700 is 13.39 mm, and

How to Identify Coaxial Cable Types?

To identify the type of coaxial cable, check the numbers and letters printed on the cable jacket. This will tell you the manufacturer, rating, and more information about the cable.

Coaxial Cable Signal Loss (Per 10 Feet)

As signal travels through coaxial cable, it loses energy, resulting in signal loss. This loss is measured in decibels (dB), which are measured exponentially. A loss of 3 dB means a weakened signal by 2x!

According to the image provided, the Wilson400 and RG-11 are the most effective cables with the least signal loss per 10ft. The RG-6, commonly used in home installations, is almost twice as ineffective compared to the Wilson400 and RG-11. The LG600 and Half-Inch cables are even more powerful, but they come with a higher price tag.

It's important to note that the RG-174 should not be used in any unit that needs more than 6 feet of cable. It does not carry signal well at 10 feet.

Mixing and matching 50 Ohm and 75 Ohm cables and systems can lead to further signal loss. It's best to stay consistent with the same type of cable and system throughout your installation.

To calculate the amount of signal loss you should expect, you can use online calculators such as the QSL Loss Calculator. While there are many online calculators available, it's important to note that manual calculation formulas are also available.

Remember, signal loss is inevitable, but choosing the right cable and system can minimize the amount of loss you experience.

Important Coaxial Cable Features to Consider Before You Buy

Coaxial Cable Length and Thickness

When purchasing a coaxial cable, it's important to consider the cable's length and thickness. The length of the cable will determine the strength of the signal transmitted. The longer the cable, the more loss occurs when transmitting signals across long distances. Thick cable features lower loss than thin cable, making it ideal for long cable runs. For optimal transmission, you'll want the shortest and thickest cable appropriate for your application.

In radio systems, cable length is comparable to the wavelength of the signals transmitted. The characteristics of the cable, such as the outside diameter of the inner conductor, inside diameter of the shield, dielectric contact of the insulator, and magnetic permeability of the insulator, all affect the quality of the wavelength going through your cable.

Coaxial Cable and dBm

When choosing a coaxial cable, it's important to consider dBm, which represents signal strength. The type of coaxial cable used will determine how strong a signal your cable can handle.

Coaxial Cable Impedance (Ohms)

Impedance is the amount of resistance waves moving through the coaxial cable encounters. The lower the impedance, the easier the waves flow through the cable. Each type of cable has an impedance rating. Factors affecting this are the size and materials of the cable.

Standard coax impedances are 50 and 75 Ohms. When tested, these impedance ratings were deemed a great balance between power handling and low loss. While 50 Ohm cables transmit signal better, it doesn't mean you need 50 Ohm cable.

50 Ohm cables tend to be better for high power handling applications. These could be commercial boosters, broadcasting TV transmitters, and ham radios. 75 Ohm cables are the popular choice for home and office applications. They're used for residential signal booster installations, cable TV boxes, internet routers, and the like. These are general rules and do not apply to all types of cable.

When choosing cable, avoid mixing and matching 50 Ohm and 75 Ohm cables and systems. You should aim to use the same impedance throughout to prevent additional signal loss.

Coaxial Cable and PIM

When connecting two metals, the result is nonlinear elements, and distortion in the signal may occur. As signal amplitude goes up, the effects will be more significant. This often happens when connecting antennas, cables, and connectors. PIM problems occur most often in cellular networks. To mitigate PIM issues, consider low-PIM cables, connectors, and adapters.

Coaxial Cable Rating

All coaxial cables are rated for different applications. The rating tells you everything you need to know about where the cable can be SAFELY installed. The most common are:

• Communications Multipurpose Plenum (CMP) Cable: Plenum cable is designed to be used in plenum air spaces. The jacket is fire-retardant and low smoke. In the event of a fire, plenum cables release the lowest level of toxic fumes. They are the safest to use in spaces designed for air circulation.

• Communications Multipurpose Riser (CMR) Cable: Riser cable is mainly used to run cable between floors through risers or vertical shafts. The jacket is also fire retardant to prevent fires from spreading between floors. Though, they are not as heavy-duty as plenum cables.

• Communications Multipurpose (CM) Cable: CM cable, sometimes referred to as PVC cable, is the most commonly used cable rating. It's rated for general-purpose applications, such as connecting a computer to the wall. It's not as fire-retardant and will release toxic fumes. They are not to be used in riser or plenum spaces.

Coaxial Cable Connectors

Connectors are on each end of the cable. They are designed to maintain the integrity of the cable as it transmits signal. They are usually plated with high-connectivity metals, such as tarnish-resistant gold or silver. The type of connector you need depends on what you are connecting to.

There are various types of coaxial cable connectors, including SMA, SMB, F-Type, N-Type, FME, TNC, and UHF connectors. Standard polarized male connectors have threads on the inside of the shell and a pin. On the other hand, standard polarized female connectors have threads on the inside of the shell and no pin. The hole and pin are switched in reverse polarized connectors. In other words, the female connector has the pin, and the male connector has the hole.

The only way to connect a male to male or female to female is with a coax cable adapter, which also causes signal loss. Signal attenuation from an adapter will depend on the quality.

When choosing a connector, check the plug on your device to

Putting It Together

RG-6 Cables with F-Type Connectors

For residential wiring, RG-6 cables with F-Type connectors are the most commonly used coaxial cables. They are 75 Ohm cables that come pre-wired in many homes, making them easy to install. These cables are ideal for average home installations that cover 2,500 to 5,000 sq ft, with cable lengths ranging from 2 to 50 feet. They are available in white or black, depending on the length. RG-6 cables with F-Type connectors are compatible with weBoost Home MultiRoom and weBoost Home Room.

RG-11 Cables with F-Type Connectors

RG-11 cables with F-Type connectors are also 75 Ohm cables, but they have a longer range compared to RG-6 cables. RG-11 cables are recommended for installations that require more than 50 feet of cable. They come in cable lengths ranging from 2 feet to a 500-foot spool and have lower loss. RG-11 cables with F-Type connectors are compatible with weBoost Home Complete, weBoost Office 100 75 Ohm, and weBoost Office 200 75 Ohm.

LMR®400 Equivalent Cables with N-Type Connectors

Wilson400 cables are pro-grade coaxial cables that are designed for large installations ranging from 7,500 to 50,000 square feet. They are 50-ohm cables that come in cable lengths ranging from 2 to 1000 feet, spooled. Installers typically apportion the cable into shorter lengths to cover the installation range while maintaining quality signal strength. Wilson400 cables are fitted with N-Type connectors, which are large connectors designed to be used with thick, commercial cable.

For running cable through plenum airspaces, Wilson400 Plenum cable is available. It features ultra-low-loss and comes in a 500-foot spool with no connectors. Cable can be easily terminated to fit any application. Wilson400 cables are compatible with weBoost for Business and WilsonPro line of commercial signal boosters. However, they are compatible with any equipment that uses 50 Ohm cables fitted with N-Connectors.

LMR®600 Equivalent and LDF4/AI4 RPV-50 “Half Inch” with N-Type Connector

LMR®600 and LDF4/AI4 RPV-50 “Half Inch” coaxial cables are recommended for installations that require cable lengths in excess of 150 feet. These cables are much thicker and more industrial than any other variety, and they are expensive. Installers only recommend these cables in rare, specialized situations depending on individual needs. LMR®600 and LDF4/AI4 RPV-50 “Half Inch” coaxial cables are the best available cables to maintain quality signal strength on the market.

The difference between an LDF4 and an AI4 RPV-50 is the interior - the LDF4 has a foam covering, and the AI4 RPV-50 has nothing. However, the difference in function is minimal.

RG-58 and RG-174 Cables with SMA Connectors

RG58 and RG174 cables are used in vehicle boosters. The RG58 has better low-loss quality with cable lengths up to 20 feet compared to the RG174, which has a range of 6 feet. For large vehicles such as RVs or boats, the RG174 is preferred. Both cables are fitted with SMA connectors, which are small copper connectors used in modems and other devices. They are relatively inexpensive, which allows for the cable’s cheaper cost. RG-58 and RG-174 cables with SMA connectors are compatible with weBoost Drive Reach, weBoost Drive Sleek, and the weBoost Drive X.

Coaxial Cable Advantages and Disadvantages

Coaxial cable has both advantages and disadvantages. The advantages of coaxial cable include durability, good electromagnetic interference resistance, affordability, easy customization and expansion, and easy wiring and installation. However, it can be bulky and an eyesore if not hidden, expensive to professionally install for long runs, cable failure can cause your entire network to go down, and it is fragile.

How Do I Choose Coaxial Cable?

When choosing a coaxial cable, it is important to consider several factors to ensure optimal performance. The type of device being used and the location of the cable installation are key factors to consider.

Different devices may require different cable types based on their impedance, rating, and connectors. It is important to reference the specifications of your device to determine the appropriate cable type.

The distance between the transmitter and receiver is another important factor to consider. The cable should be as close to the calculated distance as possible to minimize signal loss. Thicker cables also have less loss than thinner cables.

Impedance matching is crucial to minimize signal loss. It is important to ensure that the impedance of the cable and the devices match.

When calculating loss, various online calculators are available to assist in determining acceptable loss based on your devices and application.

In summary, when choosing a coaxial cable, consider the device being used, the location of the cable installation, the distance between the transmitter and receiver, and impedance matching to ensure optimal performance.

Coaxial Cable FAQ

What is the Transmission Speed of Coaxial Cable?

Coaxial cables transmit data at varying speeds depending on the type of cable and technology used. The transmission speed of coaxial cables ranges from 10 Mbps to over 100 Mbps. The speed is determined by the internet service provider, cable company, or other technology that uses the cable.

Does Coax Cable Go Bad?

Coaxial cable can last for years, but it can go bad due to various reasons. Heat damage, physical damage, water damage, and connector damage are the main culprits. To increase the longevity of the cable, it's important to buy the right cable, install it correctly, weatherproof the connectors, and avoid bending it.

Can I Install Coaxial Cable Outdoors?

Yes, coaxial cable can be used for outdoor applications with additional insulation to protect the wires. Outdoor-rated cables may run along the outside of your home to an antenna or cable box on the corner. It's important to protect the cable from the elements to ensure seamless transmissions. However, our coaxial cables are outdoor rated but not direct burial rated.

Does It Matter What Coaxial Cable I Use?

Yes, it matters what coaxial cable you use. Different applications require different types of cables. For example, a signal booster might need a different cable than radio systems. To ensure the best results, it's important to use a cable that's appropriate for your application.

Manufactures of Coaxial Cable

As a leading provider of coaxial cables, Bolton Technical offers a wide range of cables, connectors, and antennas used in high-end electronics and equipment. Wilson Amplifiers, on the other hand, is a well-known provider of cellular boosters and coaxial cables. They offer high-quality coax cables that ensure a stable connection.

Both companies offer free consultation with their US-based customer support and free shipping. Wilson Amplifiers also guarantees better signal or a 90-day money-back guarantee with no questions asked. Additionally, they provide lifetime technical support and a 2-year warranty for all products.

It's important to note that LMR® is a registered trademark of Times Microsystems.

Coaxial Cable Sources

I have found several helpful resources for understanding coaxial cables, including a calculator for attenuation and power handling, explanations of how coax cables work, and information on RG numbers and transmission line impedance. Additionally, I have learned about the common reasons why coaxial cables may go bad. For more information, I recommend checking out the Signal Boosting Info Center.

Frequently Asked Questions

What are the different types of coaxial cable connectors?

Coaxial cable connectors are used to connect coaxial cables to devices such as TVs, antennas, and modems. There are several types of coaxial cable connectors, including F-type, BNC, and RCA connectors. F-type connectors are the most common type and are used for cable TV and satellite connections, while BNC connectors are commonly used for video surveillance systems. RCA connectors are used for audio and video connections.

What is the difference between RG6 and RG11 coaxial cable?

RG6 and RG11 are both types of coaxial cable that are commonly used for TV and internet connections. RG6 cable is thinner and more flexible than RG11 cable, making it easier to install. However, RG11 cable has a higher signal-carrying capacity and is better suited for longer cable runs and higher frequencies.

How do I choose the right coaxial cable for my TV antenna?

When choosing a coaxial cable for your TV antenna, it is important to consider the length of the cable run, the frequency range of your antenna, and the signal strength in your area. A thicker cable with a lower signal loss is ideal for longer cable runs, while a cable with a higher frequency range is better suited for antennas that receive a wider range of frequencies.

What is the best coaxial cable for internet?

The best coaxial cable for internet depends on the speed of your internet connection and the length of the cable run. RG6 and RG11 cables are both suitable for internet connections, but RG11 is better suited for longer cable runs and higher speeds.

How can I reduce signal loss in my coaxial cable?

Signal loss in coaxial cables can be reduced by using a thicker cable with a lower signal loss, minimizing the length of the cable run, and using high-quality connectors. Additionally, using a signal booster or amplifier can help to boost the signal and reduce signal loss.

What do the numbers on a coaxial cable mean?

The numbers on a coaxial cable refer to the cable's specifications, including the cable type, impedance, shielding, and jacket material. For example, RG6 cable has a characteristic impedance of 75 ohms, while RG11 cable has a characteristic impedance of 50 ohms. The higher the number, the thicker the cable and the better it is at carrying a signal over longer distances.