Can You Have Cable Internet and an Antenna on the Same Cable?

By Greg Martinez / December 16, 2019
OTA antenna and cable internet signals on same coaxial cable

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These days, the idea of being without internet service seems almost comical. (See “Miracle Teenager Survives on His Own for Almost 6 Hours With No Wi-Fi.”) It’s not just teenagers.

Most of us are “internet enabled” in our personal and professional lives. At the same time, we’re also busy trying to cut the cord with our cable providers to save money.

Cord cutters, or people who drop their television service in favor of streaming video and over-the-air television (OTA) antennas, are usually unable to sever all links with telecom providers, largely because they still need internet.

Cable companies provide internet directly, whereas satellite television providers usually partner with other carriers to provide the service.

So while it’s possible to save money by installing an antenna in your home to receive signals from nearby transmission towers, it’s not going to bring you internet service.

Which means, you’ll need to retain at least some relationship with the cable company, unless you’re willing to go without internet, or you have unlimited data and excellent connectivity from your mobile service provider.

Cord Cutting as a DIY Activity

Cutting the cord often means swapping convenience for a lower telecom bill. Sure, a bundled service means a technician has come to your home to set up cable TV and internet to your devices with no mess of wires and cabling.

After this, the most onerous task left to you is figuring out how to work the remote control.

When you choose to look for lower-cost options, there’s far more do-it-yourself work involved.

By cutting the cord, many homeowners accept that their new setup will no longer involve the neat arrangement of a single cable modem with nearly-hidden coaxial cables leading to the different TV sets in the home.

Instead, a slightly more complicated and messier arrangement of added streaming boxes, sticks with dongles protruding from TVs, and extra cables and antenna amplifiers may come into being.

Messy cables

Reducing the Mess: Can You Combine a Cable and Antenna Signal on the Same Coaxial?

In an effort to save yourself time and the necessity of installing additional coax cable, you may wonder if you can merge the cable signal coming into your house with that of your OTA antenna. Cable TV and internet use the same line anyway, right?

On the face of it, it seems like a good idea. After all, the coax cable for internet is probably similar to that of your antenna’s. Combining both signals (in theory) would allow you to take advantage of the company’s existing infrastructure for your own OTA television.

So you’d want to combine your cable and OTA signals in a way that reduces the sheer number of cables needed and makes your home setup more efficient and easier to maintain. Intuitively, it seems like the kind of thing you should be able to do.

In the industry, a home MoCA network can be used for this. It’s a way to achieve a sort of local, digital highway by running multiple types of data traffic over your home’s existing coax cable.

For those not using a MoCA network, installing a diplexer to combine signals at different frequencies on the same cable may look like a good way to use existing cable wiring and splitters for cable service and your antenna signal.

Using diplexers to run OTA antenna signal and cable Internet on the same cable

The potential benefits are obvious: it would reduce the amount of coaxial cable needed for both feeds, running to all televisions in the home.

It promises to reduce your maintenance drudgery, since it would be less equipment to install, monitor, and care for.

It’s also aesthetically pleasing, as no one wants their living room to look like a network operations center with multiple wires hanging out of the walls, trailing over the floor, and collecting dust bunnies and pet hair.

The cable box is already grounded as well, effectively distributing signal throughout the home, so why not make use of it in your cord cutting adventures? As it turns out, there are very good reasons not to share signals on the same coax.

7 Reasons Why Combining Internet and an Antenna on the Same Cable is Risky

The pitfalls and risks relating to combining cable internet and antenna on the same cable have to do with how cable providers propagate signals.

1. The Signals May Overlap

Keep in mind that broadcast TV signals travel down a wire at the same frequencies over which they propagate through the air.

So the frequencies used by a cable signal and those used for OTA television might be the same ones…then again, they might not.

TV uses VHF and UHF frequencies of 47 to 608 MHz. Your cable internet service will generally use a frequency range of 54 to 1000 MHz, which means there’s considerable potential for (coincidental) overlap.

2. Cable Providers Have Some Leeway in Deciding How to Propagate Signals

Unlike with radio waves traveling through the air (where spectrum must be carefully allocated by the FCC to avoid conflict), internet signals can be transmitted across different mediums, and your cable provider is free to choose which frequencies they use for running data over their lines.

They’re not worried about whether it will inconvenience you.

3. Even If Signals Don’t Overlap Today, They May Next Month

Even if you’ve discovered that your antenna signal doesn’t overlap with cable internet, your provider can and does change the frequencies they use for internet, which can lead to conflicts down the road.

4. You May Draw the Ire of Your Cable Provider

While cheesing off the cable provider might seem satisfying, it’s important to understand that when you introduce radio frequency signals onto a coaxial cable, those signals potentially travel both up- and downstream.

This means that your OTA radio frequency signals could wind up essentially polluting the upstream with interference, which could cause problems in your neighborhood.

5. Your Neighbors Might Declare War on You

They may seem like nice people. You may barbecue with them in the summertime or arrange playdates with their kids and yours. But if your antenna causes their cable television reception to go wonky on Superbowl Sunday, you might find yourself the outcast of the neighborhood.

If your neighbors begin experiencing a bad picture and/or an outage, they’ll question what’s going on and might complain to their provider. A little investigation on the company’s part, and you’ll quickly be exposed as the culprit.

Cable technicians, cellular service providers, and even ham radio operators will come running – and won’t be pleased with your well-intentioned efforts.

6. You Might Be Breaking the Law

Here’s where things might get really sticky. Aside from complaints from your neighbors about interference, cable providers – along with other licensed broadcasters – are required by federal law to monitor their broadcasting each quarter to make sure their signals aren’t leaking into spectrum they’re not supposed to.

Which means they’ll possibly be looking for culprits using leakage detection technology.

If you’re cross-connecting and polluting the signal output in your neighborhood, you’ll register on the monitoring equipment when technicians check your neighborhood.

In extreme cases (such as leakage into public safety channels), the FCC could issue monetary fines.

7. You Could Lose Your Cable Entirely

According to the FCC, to pinpoint a leakage source for repair, a cable repair operator might request access to your home.

While you’re free to deny access to your home to their technicians when they come to question you, they’re also free to disconnect your cable service if they suspect you’re the source of the interference.

Yeah, But What If I Get Away with It?

In most cases, the cable company probably won’t notice what’s going on, but you might. Your coaxial cable internet might simply disappear on a line being shared by your cable signal and antenna. (And you know it’ll happen 10 minutes before the next season of “Walking Dead” starts.)

In the best-case scenario, you might determine that the frequencies used by the cable company for internet are not those used by your local stations for television broadcasting, and you’re willing to take the risk things will stay that way.

There still remains the problem that the antenna cable connection will cause leakage through the cable modem and interfere with just about any connected system.

In some cases, intrepid and determined antenna and internet users have tried to ask their cable providers to filter the cable TV channels out, which in theory would eliminate the possibility of interference.

Whether the cable company would be willing to do this – and whether it would be effective if they did – is still a big question.

But it’s general wisdom that telecom providers are seldom willing to do things that would lose them revenue.

But People Cutting the Cord with Satellite Can Do It!

There’s a good reason for this. Satellite internet subscribers have more leeway to use the same cabling.

It’s possible and even easy to put OTA TV and satellite signals on one cable because satellite TV has been allocated higher bandwidth frequencies.

Satellite dish receiving internet

Satellite internet subscribers can therefore use the existing coax cable for their OTA antenna, which eliminates the need for a new wire. It may not seem fair, but hey… you can’t argue with physics.

A Separate Coaxial Cable Is the Best Solution

Here at Long Range Signal, we recommend that you simply install a separate coaxial cable for your outdoor antenna signal.

Heck, you’ve spent money on a good television and you’ve gone through the expense of installing an antenna, so take the time to ensure that you’re getting the best out of your hardware.

Sure…the FCC is busy chasing illegal robocallers, but it would make time for you if your coaxial shortcut began causing noise on emergency channels.

The good news is that running a new line isn’t all that difficult or complicated; it just requires some elbow grease and a few tools. The hardest part will be getting the antenna output cable through your roof and into your home.

I advise seeing whether you can get the line through your attic, which would reduce the amount of drilling on your home’s facade.

Before you begin, ensure that you have a cable of the appropriate length to run through your bedroom or other rooms. Take the time to understand the route in order to avoid sharp turns and bends.

  • I recommend using RG6 cable such as this one from Mediabridge, which is tri shielded and 75 Ohm to minimize interference (not all RG6 types are tri or quad shielded, so I’d specifically look for this).
  • The coaxial cable should take as direct a route as possible to your television in order to minimize the effects of interference and signal leakage.

Once you’ve threaded the cable through, be sure to caulk around holes and waterproof other coax connections to prevent moisture from outside getting in and causing corrosion.

Set Top Boxes Make Life Easier

Thanks to newer technology, you won’t have to run the OTA antenna cabling to every television in the house. 

Boxes like those made by HDHomerun (which include ATSC tuners) connect via Ethernet to your WiFi router or networking hub, allowing you to wirelessly access the antenna signal from multiple devices courtesy of an app on your phone or tablet.

Setting up an HDHomerun device – which I recommend for distributing OTA television signals throughout your home WiFi network – is a convenient proposition for enjoying free ABC, NBC, CBS, FOX, etc.

Cable Providers Might Make Things Easier in the Future

The good news is that providers are increasingly realizing that cable television (in its current form) is on track to become a dud sometime in the future.

Customers increasingly don’t want bundled services, which used to represent a substantial source of revenue for providers.

Even so, many providers have resisted moving to an “a la carte” model in which subscribers choose and pay for only what they want, which is why these providers share a lot of the blame for the trend of cord cutting.

A few providers – such as Arizona-based Sparklight (formerly Cable One) – are actively poised to market internet-only services, since they recognize that’s where the future is.

As other providers increasingly follow suit, perhaps the idea of cable internet and an antenna signal located on the same cable will become more of a reality.

For now, however, if you’re going through the not-inconsiderable effort of cutting the cord and setting up an antenna to receive free television, make sure your efforts aren’t wasted and take the time to do it properly.

Rick Gyzen - December 23, 2019

I’m not aware that I can break the law by doing such a small thing like that, Thanks for this informative article. I also don’t want to ruin the great relationship with my neighbors lol

Aldebarano - December 28, 2019

Is there really an HD coaxial cable?

    Greg Martinez - December 29, 2019

    Hi, not sure where you heard that from but that’s, well, bull.

Kyree Vogl - January 20, 2020

Can I use my antenna cable as my internet cable? I have one from the cable company but it’s too short.

    Greg Martinez - January 22, 2020

    Well I would say no since it will cause the issues described in this article – if you’re trying to use them simultaneously. If however you’re using them separately, check if they’re the same type. Good luck!

Karl Kaufman - June 9, 2021

Rough article. Spends a lot of time making people think they might be able to fuse Internet connectivity and OTA, but ultimately bails on the subject.

Given the article recognizes MoCA as an option, the simple solution is to move the cable modem to a location where it can be directly connected to the provider feed, while also allowing a linked MoCA adapter to connect to the shared coax plant, and remote MoCA adapters extending wired LAN connectivity where needed.

With cable signals eliminated from the shared coax plant, the raw OTA signal could then be introduced without concern for overlap.

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