How to convert your home’s old TV cabling into powerful Ethernet lines
Take a deep breath. It’s not as scary as it looks… I promise. Michael Gariffo/ZDNET
If you don’t already know it from self-installing set-top boxes or broadband modems, coaxial cable (see above) is the round, usually white, somewhat stiff cable that carries all forms of pay-TV services, including cable and satellite-based subscriptions. For decades, wiring ran through almost every home that ever had a pay TV or Internet connection.
But as technology progressed, many users turned away from these TV services to stream our TV shows and movies over the Internet. While many homes still use a single coaxial cable line to carry their broadband signal to a modem, even these have often been replaced by Ethernet as many ISPs require its use for any level of service above 100Mbps.
Review: Slow Internet at Home? This adapter can convert your unused coaxial cable to Ethernet
Because of these transitions, millions of homes are left with seemingly useless coax cables and coax outlets sticking out of walls and floors. But don’t rip out all the wiring just yet. With a few relatively inexpensive adapters, you can use the wires that already run a spider’s web through your home to transmit the same data that would otherwise require hundreds of feet of expensive Ethernet cable. In fact, it can connect any two devices that use Ethernet connections – modems, routers, switches, PCs, streaming devices, and more – even if they’re on opposite sides of the house. Read on to find out how you can turn that unused coaxial cable into a ready-to-use whole-home network.
Here’s how to convert your house’s old coaxial cable into useful Ethernet lines
- Materials needed: Built-in coax cables, a coax to ethernet adapter kit, any networking hardware you want to connect
The first, and often the most difficult, step in this process is to locate the coaxial cable line that you want to adapt to Ethernet. Since most cable runs run inside walls, it helps tremendously if the cable is tagged at both endpoints. Unfortunately, that’s not always the case.
This is a great time to have a friend or family member on the phone with you to support this process. If you have a bare coax line sticking out of the wall, it can be as simple as wiggling one end while you watch the other for movement. Or, if you have a built-in outlet, it may take a little more detective work to visually verify which wire is which.
If the worst comes to the worst, the rest of the process is so easy that you can just guess, and if you’re wrong you can start with your next best candidate for the line running to your desired endpoint. Or, if you’re short on time, there’s an extremely helpful tool we cover in the Frequently Asked Questions section below that can speed things up.
The termination will either look like this (if it’s a wall mounted connector) or one of the many cables pictured in the instructions above. Getty Images
Once you have verified (or best guess) the line of your choice, the next step is to start connecting the adapter kit you purchased. We’ve listed several adapter candidates below and encourage you to choose the model that best meets your speed and security goals.
To install the adapter you need to make a total of three connections:
- coaxial cable: depending on the model, is screwed into the connection marked G. Hn., In or MoCa (Multimedia over Coax Alliance).
- Ethernet: clicks into the Ethernet port
- Perfomance: should normally be connected last
The type of power supply varies from manufacturer to manufacturer, but is almost always needed to provide the power used to convert and transmit your Ethernet signal over coaxial cable.
Some adapters may also have a TV or line-out connector for a second coaxial cable. This is used when you want the same cable to continue carrying a TV signal. While it’s possible to have an active cable or other pay-TV connection running on the same line, we recommend avoiding it. The two competing signals can interfere with each other, resulting in poor performance for both.
These are (from left to right) the ethernet cable, the coaxial cable, and the power cable that we will connect to our adapter. Michael Gariffo/ZDNET
This is the same as the previous step, only done one more time at the other end of the coax run you chose.
The placement of each adapter depends entirely on your goals for this new coax-to-ethernet run. For example, if you’re trying to connect your incoming broadband connection to a modem or router located elsewhere in your home, you’ll want one adapter wherever the broadband connection enters your home and the other where you want it on the router , between which there is a coaxial line.
If you want a wired connection from an existing router to a home theater setup in the basement for reliable 4K (or even 8K) streaming, place one adapter near the router and the other near your home theater.
It is important to think of these adapters only as endpoints for an Ethernet run. With their help, any old coaxial cable can become just that.
Your adapter should look something like this when fully connected. That empty coax connector is there if you still want to power a TV through the same cable path, which we don’t recommend. Michael Gariffo/ZDNET
Once you’ve got your adapters up and running, the final step is to plug in any networking hardware you want to connect to your newly created connection. This can include anything like the examples in Step 3, as well as other streaming devices, network switches, PCs, wireless network extenders, and similar technologies. Again, anything that could normally be connected via Ethernet is a candidate.
Once you’ve plugged in your other networking hardware and verified that the connection is working, you should be done with your new home network setup.
You can repeat this entire process to convert other coax cables to Ethernet, but you’ll need a different set of adapters for each one.
Once your adapter setup is complete, you can connect your streaming devices, additional network hardware, PCs, and other devices. Getty
frequently asked Questions
Which adapter should I buy?
It all depends on your goals for the run, the level of security you want, and other factors specific to your home and devices. However, we’ve rounded up some good candidates for the most common scenarios below.
This is the adapter we used in our demonstration. It includes built-in encryption for security and offers maximum speeds of up to 2Gbps. Read our full review of the Nexuslink G.hn Ethernet Over Coax Adapter here.
A starter kit that supports MoCa 2.5 to power entire home networks over a single coaxial cable. A great option for those upgrading to a faster tier of broadband that would otherwise require an Ethernet installation.
A cheaper alternative to the model above that offers very similar features but comes with a few fewer adapters that you may need to provide yourself depending on the situation.
Can I use this method to connect my entire home to my ISP?
Yes. One of the main reasons adapters like these are used the most is to help customers upgrade from slower (100 Mbps or so) broadband connections to faster (300 Mbps or more). Because many broadband connections over 100Mbps require Ethernet cabling from their point of origin to a modem or router, many customers faced a huge bill to upgrade their existing coax connections (which were fine up to 100Mbps) with the required length to replace Ethernet. Instead, these adapters provide a way to convert the existing coax cable to Ethernet at both ends, allowing you to connect broadband hardware, even hardware up to 1Gbps, to a modem or router using your existing coax cable.
If you intend to do this, we recommend you choose an adapter kit that uses the bonded MoCa 2.5 protocol. This is a standard developed by the Multimedia over Coax Alliance (MoCa). It’s rated for up to 2,500 Mbps (2.5 Gbps) and is designed to carry the type of traffic that an entire network is likely to generate. Other adapters may work, but you may experience some slowdown depending on the specific protocols and technologies they support. Of course, you don’t want to pay for gigabit broadband only to accidentally throttle yourself to less than 300Mbps by using the wrong hardware.
What if I’m having trouble figuring out which coaxial line is which?
In homes with many televisions, all hooked up to cable or satellite hardware at one point, you could be dealing with dozens of coaxial cables running through walls. Unless you’re lucky enough to have them helpfully labeled, following each run can seem too daunting. Luckily, there is a very helpful tool that can speed up the process.
With this inexpensive device, you can plug one end into a coaxial cable, go to the other end, and screw on a tiny speaker. If you hear a tone, you’ve found a complete run. If not, you’ll need to try a different endpoint. It’s a big help if you have coax sockets in the wall that prevent the “wiggle” method, or if you don’t have help on hand to sit at the other end. I’d recommend buying one if you’re serious about using your house’s defunct coax for more than one run.
What are some other uses for coax to ethernet conversion?
As mentioned above, essentially anything that could be handled by an Ethernet link could also be handled by a coaxial cable with the appropriate adapters at both ends. But just to get you started on how diverse these possibilities are, we’re including a handful of other example scenarios below. You could…
- Use a coaxial cable to hard-wired connection to a Wi-Fi extender to counteract a Wi-Fi dead zone in your home or office.
- Connect a gaming PC via matched coaxial cable to reduce the game-changing latency that Wi-Fi can sometimes cause.
- Create a fast, wired connection between a NAS (Network Accessible Storage) device and a remote computer or media streaming setup.
- Install an over-the-air broadcast antenna and receiver that you use with a matched coaxial cable to connect to your LAN for streaming or recording.
- Skip the hundreds or thousands of dollars a contractor might charge to install Ethernet cables in the wall for other purposes.