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How to Tell Which Coax Cable is for the Internet

After going through this article, you can identify the internet coax cable from all the cables at your home.

Coax cables are used in many areas, such as voice communication, video conveying, and internet data. Consequently, identifying the coax cable used for the internet is a little tricky. So, which coax cable should I connect to my router? Here’s how to tell which coax cable is for the internet.

Generally, you can use the RG ratings on the wires to identify the internet coax cable. RG-8, RG-6 and RG-58 cables are commonly used for internet data transfer. You can locate these markings on the connector end of the coaxial cables or the middle.

Read the below article for a detailed breakdown.

The Best Way to Identify the Internet Coax Cables

hand holding a white coaxial cable
Video | Techbotic

Currently, coax cables are used in radio, TV, and internet connections.

You might be looking into a bunch of coax cables, and you don’t know which one is which. You won’t know which cable you should connect to the router in an emergency. That is why identifying the internet coax cable is so important.

With that in mind, here’s a simple and quick way to find internet coax cables from the rest.

Identifying the Coax Cable by RG Ratings

rolled coaxial cable
Video | Techbotic

RG ratings are the best way to identify internet coax cables. But what are RG ratings?

RG stands for Radio Guide. When categorizing coax cables, manufacturers use this RG marking with numbers such as RG-6, RG-59, RG-11, etc. This RG designation represents different types of coaxial cables.

The coax cables used for internet connections are RG-6, RG-8, and RG-58. These three types are the most common ones.

So, all you need to do is search for this RG marking on the cable, and the marking should be located at the connector end of the cable or the middle.

However, if you use old cables, you might not be able to see the marking properly. Sometimes, the marking might be covered with dust. Clean the wire and look for the RG rating if that is the case.

You need to know some things about the above RG-rated coax cables.

RG-58 and RG-6 coaxial cable in zoom
Video | HBT

Check the above image. It is a comparison of RG-58 and RG-6 cables. The cable on the left is the RG-58 and the one on the right is the RG-6. As you can see, the RG-6 cable is thicker than the RG-58 cable. With that comparison, you can easily comprehend the size of the RG-8 cable.


The RG-58 cable is mainly used for 50-ohm applications. It measures 20 AWG.


RG-8 is a thicker 50-ohm cable. It measures 12 AWG.


RG-6 cable is capable of handling 75-ohm applications. It measures 18 AWG.

Which Cable is Best for the Internet?

I think all the above three cables are good options for the internet. But if I had to pick one, I’d choose RG-6.

The RG-6 cable comes with a heavier gauge and thick insulation. Similarly, its high bandwidth is excellent for applications like the Internet, Satellite, and Cable TV.

You now know how to find the coax cable best for the internet. But do you know how to find which coax outlet has the best signals?

For that, you’ll need a coax cable tester. And here’s how you can use that to find the best coax outlet.

  • Turn On the coax cable tester.
  • Bring the tester close to the particular outlet.
  • If the LED light indicator lights up red, the signal is weak.
  • If the LED light indicator lights up green, the signal is strong.

Quick Tip: A coax cable tester is a better option than contacting customer support whenever you lose signals.

Must Know Things About Internet Coax Cables

The Design

These internet coax cables come with a round, thick design and have a center conductor made from copper. However, the insulation takes much of the cable’s thickness (not the copper conductor). Because of this large insulation, the copper conductor can transmit data without external damage or interference.

The plastic dielectric insulator protects the copper conductor. You can find a metallic shield on the top of the plastic dielectric insulator. Lastly, the outer plastic jacket protects the inner insulation and the conductor.


Transmitting data through the copper conductor is the functionality of the internet coax cables. Because of the additional layers, you won’t experience any signal loss. In other words, it reduces electromagnetic interference.


These internet cables can transmit data from 10 to 100 Mbps (megabits per second).


How Far Can an Internet Coaxial Cable Run?

Coax cables are famous for running longer than most other cables. They can run up to 500m. This value is equal to 1640.4 feet. However, this value might vary depending on the cable type and signal strength.

Does the Length of the Coax Cable Affect the Internet Signal?

Yes, the length of the cable will affect the internet signal. For instance, you’ll experience more signal loss with more cable length. This signal loss occurs due to resistance.

When a conductor’s length increases, the resistance of the conductor increases automatically. So, long distance means a higher resistance, which means internet signal loss.

Typically, the following signal loss can be expected from a coax internet cable with increasing distance.

– 20% signal loss over 50 feet run
– 33% signal loss over 100 feet run

Can I Use Any Coax Cable for the Internet

No, you cannot use any coax cable for the internet. Some are for radio or TV connections, and others for internet data transmission. So, you’ll have to buy a coax cable that supports internet data transfer. RG-6, RG-8, and RG-58 are the market’s most common internet coax cables.

What is the Ohm Value of Internet Coax Cables?

When categorizing the internet coax cable by their ohm value, there are two types of cables: 50 ohms and 75 ohms. The 50-ohm cables are mostly used for wireless and data communications. And the 75-ohm cables are used for video signals.


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About Sam Orlovsky

AvatarCertifications: B.E.E.
Education: University Of Denver - Electric Engineering
Lives In: Denver Colorado

Electrical engineering is my passion, and I’ve been in the industry for over 20 years. This gives me a unique ability to give you expert home improvement and DIY recommendations. I’m not only an electrician, but I also like machinery and anything to do with carpentry. One of my career paths started as a general handyman, so I also have a lot of experience with home improvement I love to share.

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