A coaxial cable is a round cable that carries signals between devices. It has a metal wire in the center, wrapped in layers that protect the signal. You use one when you connect a cable box, a cable modem, or a TV antenna. You also find coax in satellite TV setups, security cameras, and radio equipment.
The word coaxial means the parts share one center line. In this cable, the center wire and the metal shield around it sit on the same axis. This design helps the cable carry a signal and block outside interference. Not every coax cable is the same, though. The right one depends on your equipment and where you install it.
What Does Coaxial Mean?
Coaxial means “sharing the same axis.” Picture a target with rings. Every ring has the same center point. A coaxial cable is built the same way, with layers stacked around one center wire.
People often shorten the name to “coax.” On its own, the word usually points to the cable. Other products, like some speakers, also use it because their parts share one axis.
What Does a Coaxial Cable Look Like?
Most coax cables are round, with a smooth outer jacket. Many have a metal connector at each end. On home TV and internet gear, that connector is usually threaded. You screw it onto a round port so the cable stays tight.
Ethernet cables look different. They usually end in a small plastic plug called an RJ45 connector, and they hold twisted wire pairs inside. Many coax cables also have text printed on the jacket. It may show the cable type, such as RG-6, along with other details from the maker.
What Are the Parts of a Coaxial Cable?
Most coaxial cables have four layers. Each one has a clear job.
Center Conductor
The center conductor is the wire in the middle. It carries the signal. It can be solid copper, stranded copper, or copper-clad steel, depending on the cable’s design.
Dielectric Insulator
The dielectric is the insulating layer around the center wire. It keeps the wire and the shield apart. It also helps set the cable’s characteristic impedance, which describes how the cable handles a signal. Common materials include polyethylene and foam.
Metallic Shield
The shield wraps around the dielectric. It can be foil, braided wire, or both. It helps keep outside interference out and keeps the signal in. How well it works depends on the design and coverage, not on how thick the cable looks.
Outer Jacket
The jacket is the cable’s outer protective covering. It helps protect the inner layers from physical damage. Some jackets are also made for sunlight, moisture, or outdoor exposure. Always check the marking before you install a cable.
How Does a Coaxial Cable Work?
A coax cable sends a signal along the center wire. The shield acts as the return path. Together with the dielectric, the wire and shield form a transmission line. The signal’s electric and magnetic fields stay mostly in the space between the center wire and the shield.
That is why the shield matters. It helps block outside noise, and it helps keep the signal from leaking out. No cable is perfect, though. Signal loss grows as the cable gets longer, and it gets worse at higher frequencies. Engineers call this loss attenuation. Poor connectors, sharp bends, and damaged shielding can hurt the signal too.
What Is a Coaxial Cable Used For?
Coax carries radio-frequency (RF) and video signals between compatible devices. Here are the most common uses.
Cable TV
Cable TV providers send channels to homes over coax. The cable runs from a wall outlet to your TV or cable box. RG-6 is a common choice for home TV hookups.
Cable Internet
Many cable internet plans use coax. The cable links your modem to the provider’s network. Many providers run a hybrid fiber-coaxial (HFC) network. Fiber carries data over long distances, and coax covers the last stretch to homes.
These networks use a standard called DOCSIS to send data over the cable. Your speed depends on your plan, the provider’s network, your modem, and your signal quality. Your modem also needs to support the DOCSIS version your provider uses. Coax has no single speed limit that fits every setup.
Satellite TV
Satellite TV systems use coax to link the dish to the receiver inside your home. RG-6 is common for home dishes. The cable still has to meet the system’s needs for frequency, shielding, and installation.
Security Cameras
Older analog security cameras often use coax to send video to a recorder. RG-59 is a common choice in these systems. Newer systems often use Ethernet or Wi-Fi instead. Some modern camera systems can also send HD video over coax.
Radio and Antennas
Coax connects antennas to radios and other RF equipment. Many of these systems use 50-ohm cable, such as RG-58. TV and video systems usually use 75-ohm cable. Match the cable to your equipment.
Digital Audio
Some home theater gear has a coaxial digital audio port. It carries digital audio between devices, such as a TV and a soundbar. This port usually uses an RCA-style connector, not the threaded F-type connector found on cable TV gear. Ports for digital audio are designed for 75-ohm cable.
What Are the Different Types of Coaxial Cable?
Coax comes in many designs. The “RG” name labels a cable family, but it does not tell you everything about the cable’s build or performance. Two RG-6 cables from different brands can differ in shielding, conductor, and jacket.
RG-6
RG-6 is the most common type for home TV, satellite, and cable internet. Many RG-6 cables are 75 ohms. Designs vary by product, so check the label or datasheet before you buy.
For example, one CommScope RG-6 product (Model 2276V) lists a 75-ohm impedance, a copper-clad steel center conductor, and foil-plus-braid shielding. That is one product, not a rule for every RG-6 cable.
RG-59
RG-59 is usually a 75-ohm cable too. It has long been used for analog video and security cameras, and you often see it in older setups. Do not swap it in for RG-6 on a TV or internet run without checking the specs first. Signal loss matters most on longer runs.
RG-11
RG-11 is a thicker 75-ohm cable. Some designs lose less signal over a given distance, so they can suit longer runs. But thicker is not always better. RG-11 is stiffer, often needs larger connectors, and can be harder to route. Compare signal loss at the same frequency and length before you choose it.
RG-58
RG-58 is usually a 50-ohm cable. It is common in radio, antenna, and test setups. It is not a drop-in swap for the 75-ohm cable used in TV and video systems.
RG-6 vs. RG-59 vs. RG-11 vs. RG-58
| Cable | Common impedance | Common uses |
|---|---|---|
| RG-6 | 75 ohms | Cable TV, satellite, cable internet |
| RG-59 | 75 ohms | Analog video, security cameras, older systems |
| RG-11 | 75 ohms | Some longer video and broadband runs |
| RG-58 | 50 ohms | Radio, antennas, test equipment |
These are common uses, not rules for every product with the same RG name. Always check the maker’s datasheet.
For most new home cable TV, satellite, and cable modem connections, RG-6 is a common starting point. RG-59 may still make sense for some existing video or security camera systems. Check your equipment’s requirements and the signal loss before you use it for a new run.
What Do Coaxial Cable Specs Mean?
The RG name is only one clue. These specs tell you more about how a cable will perform.
Impedance
Impedance is measured in ohms. It describes how a cable handles a signal. TV, satellite, video, and cable internet gear usually uses 75 ohms. Radio equipment and many test systems usually use 50 ohms. Use the impedance your equipment calls for, because a mismatch can weaken the signal.
Attenuation
Attenuation is signal loss. Makers usually list it in decibels (dB) per 100 feet at set frequencies. Loss rises with length and frequency. To compare two cables fairly, look at the numbers for the same frequency and the same length.
Shielding
Shielding is listed by type, such as foil, braid, or both. Many datasheets also list braid coverage as a percentage. Read the spec instead of judging by how thick the cable looks.
Frequency Range
A frequency rating shows the range a cable was designed and tested to handle. Pick a cable rated for the frequencies your equipment uses.
Bend Radius
The bend radius is the tightest curve a cable can make safely. Sharp bends, kinks, and crushing can damage the layers inside and weaken the signal. Datasheets also list the temperature range, which matters for outdoor runs.
What Do Coaxial Cable Jacket Ratings Mean?
An RG name tells you the cable family. A jacket rating tells you where the cable can be installed. In the U.S., the National Electrical Code (NEC) sets rules for cables inside buildings. Coax often carries CATV markings, while many other communications cables carry CM markings. NEC rules can vary by code edition and local area, so confirm the rules that apply to your installation.
| Marking | General meaning |
|---|---|
| CATV | Coaxial cable for community antenna TV systems; permitted uses depend on its listing and local code |
| CATVR | Riser-rated CATV cable |
| CATVP | Plenum-rated CATV cable |
| CATVX | Limited-use CATV cable |
| CM | General-purpose communications cable |
| CMR | Riser-rated communications cable |
| CMP | Plenum-rated communications cable |
| CMX | Limited-use communications cable |
These markings are not interchangeable. Do not assume a CM, CMR, or CMP marking can stand in for a CATV marking. Check the full text on the jacket and the product listing.
Plenum-Rated Cable
A plenum is a space used to move air in a building’s heating and cooling system. Plenum-rated cable (CATVP or CMP) must meet stricter fire and smoke requirements. Not every space above a drop ceiling is a plenum. The building’s design and local code decide that.
Riser-Rated Cable
A riser is a vertical path that carries cables between floors. Riser-rated cable (CATVR or CMR) is made to slow the spread of fire from floor to floor. A riser rating does not make a cable right for every plenum space.
Outdoor and Direct-Burial Cable
Outdoor cable has a jacket built to handle sunlight and weather. Direct-burial cable is made to go in the ground, where moisture is a concern. Not every outdoor cable is rated for burial. Look in the datasheet for terms like sunlight resistant, wet location, or direct burial.
How to Check a Cable’s Rating
- Read all the text printed on the jacket.
- Find the exact product number on the maker’s datasheet.
- Confirm the cable is listed for the place you plan to use it.
- Check the building and electrical code rules in your area.
- Use connectors and installation methods that fit the cable.
A cable that fits the connector is not always approved for that spot. If you are unsure, ask a licensed installer or your local building department.
What Is a Coaxial Connector or Port?
The cable and the connector are different things. The connector is the end piece that links the cable to a device. The port is the socket on the device. Ports can look alike but work with different connectors, so check the label on your device.
F-Type Connector
The F-type connector is common on home cable TV, satellite TV, and cable modem gear. It has a threaded collar that screws onto the port.
BNC Connector
BNC connectors use a twist-and-lock design. You will see them on security camera systems, video equipment, and test gear.
N-Type Connector
N-type connectors are larger and threaded. They are common in RF and antenna systems, including outdoor setups.
RCA-Style Connector
Some digital audio ports on TVs, soundbars, and receivers use RCA-style jacks labeled “coaxial” or “digital coax.” Do not confuse this port with the F-type port used for cable TV. The two carry different signals.
Coaxial vs. Ethernet vs. Fiber vs. HDMI
These cables often get compared, but each one has a different job.
Coaxial vs. Ethernet
Both can carry data, but they are built differently. Coax has a center wire, insulation, and a shield. Ethernet cable holds twisted pairs of wires.
| Feature | Coaxial cable | Ethernet cable |
|---|---|---|
| Build | Center wire, dielectric, and shield | Twisted wire pairs |
| Common uses | Cable TV, cable internet, RF, video | Home and office networks |
| Common connectors | F-type, BNC, N-type | RJ45 |
At home, coax often links the modem to the provider’s network. Ethernet often links the modem or router to your computer, TV, or game console. Neither one is better in every case.
Coaxial vs. Fiber Optic
Fiber optic cable sends data as light through thin strands of glass or plastic. Coax sends electrical signals through metal. Fiber can carry a lot of data over long distances. Coax is still widely used in existing cable TV and internet systems. The two need different equipment, so you cannot swap one for the other.
Coaxial vs. HDMI
Coax and HDMI do different jobs. HDMI connects devices like TVs, game consoles, streaming boxes, and computers. It carries digital video and audio. Coax carries signals like cable TV, internet, and RF.
A cable modem connects to the wall with coax. A streaming box connects to a TV with HDMI. So neither one replaces the other.
Advantages and Disadvantages of Coaxial Cable
Advantages
- Shielding: The metal shield helps protect the signal from outside interference.
- Range of uses: Different designs support TV, internet, RF, and video.
- Existing wiring: Many homes and buildings already have coax installed.
- Steady signal: A cable that is chosen and installed correctly can carry a signal reliably.
- Connector choices: Many connector types fit different equipment.
Disadvantages
- Signal loss: Loss grows with cable length and generally rises with frequency.
- Size: Some designs are thick and stiff, which makes them harder to route.
- Installation: Connectors, grounding, and cable ratings all matter.
- Impedance: The wrong impedance can weaken the signal.
- Damage: Crushing, sharp bends, and damaged connectors can cause problems.
How Can You Tell If a Cable Is Coaxial?
Look for these signs:
- A round outer jacket.
- A single wire in the center when the cable is stripped.
- An insulating layer around that wire.
- A foil or braided shield under the jacket.
- A connector such as an F-type or BNC, depending on the use.
Many coax cables also have text on the jacket. It may list the maker, cable type, impedance, product number, and installation rating. If you are not sure what you have, read the jacket text and check the connector instead of going by looks alone.
How to Choose the Right Coaxial Cable
- Match the impedance. Use 75 ohms for most TV, satellite, and cable internet gear, and 50 ohms for most radio setups.
- Check the connector. Look at the port on your device and pick a cable with the right end.
- Think about length. Longer runs lose more signal, so compare attenuation numbers.
- Pick the right rating. Choose a jacket rated for the place you will install it, such as indoors, in a riser, or outdoors.
- Read the datasheet. Confirm that the exact product fits your equipment.
Frequently Asked Questions
What is a coaxial cable used for?
Coax carries RF, TV, internet, and video signals. Common uses include cable TV, cable internet, satellite TV, security cameras, antennas, and radio equipment.
What does coaxial mean?
Coaxial means two or more parts share the same center line. In a coax cable, the center wire and the metal shield share one axis along the cable’s length.
Is a coaxial cable the same as an Ethernet cable?
No. Coax has a center wire, insulation, and a shield. Ethernet cable usually holds twisted wire pairs and ends in an RJ45 plug. Both can carry data, but they serve different kinds of connections.
Is RG-6 better than RG-59?
Not in every case. RG-6 is common for home TV, satellite, and cable internet. RG-59 is common in some video and security camera setups. The best choice depends on your system, cable length, and the maker’s specs.
Is RG-11 better than RG-6?
RG-11 can lose less signal over long runs in some designs. It is also thicker, stiffer, and often needs different connectors. Compare the real product specs and your installation needs before you decide.
Is coaxial cable 50 ohms or 75 ohms?
It can be either. Many TV, satellite, and video cables are 75 ohms. Many radio and RF cables are 50 ohms. Use the impedance your equipment calls for.
Can coaxial cable be used for internet?
Yes. Cable internet providers deliver service over coax-based networks. Your modem connects to that network and uses the DOCSIS standard to communicate. Your speed depends on your plan, your provider’s network, and your equipment.
Is coaxial better than HDMI?
They do different jobs, so neither one is better overall. HDMI links devices like TVs and streaming boxes. Coax carries signals like cable TV and internet.
Can coaxial cable be used outdoors?
Some coax cables are made for outdoor use, but not all of them are. Check the datasheet for sunlight resistance, moisture suitability, and direct-burial approval if the cable will go in the ground.
What is a coaxial port?
A coaxial port is a socket that accepts a coax cable connector. On cable TV and modem gear, it is usually a threaded F-type port. Other gear uses BNC, N-type, or RCA-style ports, so check your device’s label.
Can I use any coaxial cable for my TV?
No. The cable should match your system’s impedance, frequency range, connector, and installation needs. RG-6 is common for home TV, but the exact product still matters.
The Bottom Line
A coaxial cable carries signals through a center wire, an insulating layer, a metal shield, and an outer jacket. This build helps control interference and supports steady signals in the right setup. You will find coax in cable TV, cable internet, satellite systems, security cameras, antennas, and radio gear.
When you pick a cable, look past the RG name. Check the impedance, signal loss, shielding, connector, and installation rating. For work inside U.S. buildings, read the jacket markings closely, since CATV, CATVR, and CATVP differ from CM, CMR, and CMP. The right cable is the one that fits your equipment, your cable length, and the place you will install it.
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I’m Emma Rose, the founder of Punstation. I cover technology, digital trends, business, and online tools, creating practical guides and thoughtful reviews to help readers understand their options and make informed decisions. For more on how I approach my content, see our Editorial Standards.