TVs and EMFs


This page last updated January 24, 2017.


TVs are difficult these days for people who want to avoid radio frequency (RF) EMFs. That is because they now often transmit RF even when turned off and are just on standby, let alone when we are watching them. The same is true for all the set-top boxes that people now use to stream Internet-based TV, such as Apple TV and Roku.

A Bit of History: Television Delivered Over-the-Air, by Cable and Now from Telephone Companies

It all has to do with the move towards Internet-based delivery of television programming. We had over-the-air analog broadcast of TV signals, which is now digital. That has no EMF implications for you, unless you live right next to the TV transmitting tower.

We then had the addition of cable-delivered TV programming, which is also safe in terms of how the signal gets to your house, because it comes in over a coaxial cable. That does not emit significant EMFs.

After some years, telephone companies (telcos) also started to offer TV, like Verizon's FIOS (now Frontier) or AT&T's U-Verse. The television signal comes into your home on a pair of copper wires, but what was required to provide all that television content above and beyond simple telephone conversations and Internet was for the telcos to lay fiber-optic cables under the street in your neighborhood to a local box that serves several houses.

However, the "last mile" of delivery of the signal from that box to each house is still the good old pair of copper wires that the telephone company has always used to get voice telephone signals into your house. Again, there are no significant EMFs from that copper wire.

Low Voltage Hardwired Cables Don't Radiate EMFs on their Own

Any time telephone, television or Internet data is carried over hardwires, such as a coaxial cable, a copper telephone wire or Ethernet cable, that electrical signal is low voltage and does not transmit off the wires. There is no radio frequency signal that comes off hardwired cables, regardless of what type they are.

It is the case, however, that any metal path or wire can pick up radio signals traveling through the air onto your property and into your house from outside radio sources, such as broadcast towers and cell antennas. Those signals are then re-radiated at very low levels into the air around the cable or wire in your yard or in the house.

Some people who are very sensitive to electric fields, with Electrical Hypersensitivity (EHS), can indeed feel those fields and are bothered by them. However, the fields do not themselves come from the wire or cable because wires and cables do not transmit radio frequency signals directly. That comes from specific antennas in wireless devices inside your home or from outside broadcast or cell towers. The wires in these cables only re-radiate what is already in the air.

Most people, including some EHS individuals, are not bothered by signals being re-radiated off these wires. However, everyone should protect themselves from radio frequency signals coming from wireless antennas themselves, whether indoors or outside, by switching to hardwired alternatives when possible in your house and by reducing use and increasing distance from transmitters in hand-held devices. That is covered in my article on Radio Frequency EMFs, accessed from the Articles on EMFs page on my website, as well as the  Safer Use of Computers article.

Television Delivered by Satellite

A third way in which TV content is delivered into your home is by a satellite dish mounted on your roof or on a free-standing pole in your yard. People think the satellite signal is strong and therefore harmful coming from space, and for those who are EHS, it can be. However, the signal from satellites is so weak by the time it reaches earth from hundreds or thousands of miles up in space, it has to be collected by a reflecting dish that is shaped as a parabola to focus the signal to a point a few feet above the dish. That signal is then boosted and carried on a coaxial cable from the dish to a box that converts the signal and sends it to your television set or to a modem for satellite-delivered Internet.

Satellite TV and Internet, like TV and Internet provided by the cable or telephone company, is two-way, meaning, the satellite dish needs to send signals back up to space. That signal goes out the coaxial cable from your satellite TV box or Internet modem and is broadcast down onto the parabolic satellite dish, which then reflects the signal in straight lines back up to the satellite in orbit above the earth.

As long as that signal remains within the confines of the dish, it is not sent beyond the edges to the house below. Also, the metal backing of the dish blocks almost all of the RF signal from penetrating through. However, some EHS people are still bothered by being around these dishes, so if you are EHS, don’t spend time near such a dish and don't have an active satellite TV system on your house. (The dish of an old system that is not operational should not pose a problem. This is because whatever signals are reflected up to the receiver on the arm won't go anywhere, because the electronics are non-operational.)

You must understand that if we take a walk outdoors, we are exposed to several satellite signals beaming down from space, as we have been for decades. However, those broadcast signals are very weak and don't bother most people. We do have the advent on the horizon of Internet being delivered from balloons, drones and satellites much closer to earth in the next few years, which will be a problem for some EHS people. That is a separate topic, which I will address in another article.

Also, the weak satellite signals from space are easily blocked by trees, rain, roofs and a neighboring building. You can't have a satellite dish in an attic. It must be on a roof or pole in direct line-of-sight of the part of the sky where the satellite is located. The installer must align the dish perfectly with the position of the satellite high above the earth to the south, in geo-stationary orbit over the equator. So, it is easy to be shielded from signals from a satellite in space. Simple building materials block that signal.

How are EMFs Generated in a Home from TV Systems?

Since the delivery method of TV content into your home from all of these companies is free of radio frequency EMFs, whether from cable, telephone or a satellite dish company, where do EMFs come from? The answer is, from the way in which you convey the signal from one room to another within your house. There will be a central point to which the low voltage signal comes from outside the house, and from there, it can be distributed to TVs around the house in two ways, just like the Internet. That is, in a hardwired or wireless way, or both. We recommend that this be done in a hardwired way to avoid wireless RF EMF frequencies in our living space. However, the TV and the TV-content delivery device can itself still transmit RF even when on standby. Let's talk about the different companies that deliver TV into your home one by one.

TV Signals Sent Around the House by Telephone Companies

Telco-delivered TV will come by FIOS or U-Verse, or some variation on that technology. The telco brings the TV signal to a modem through an Ethernet cable that is directly connected to their copper pair of wires at the telephone network Interface device, or NID. This is the demarcation box on the side of your house between the telco's neighborhood lines and the telephone wiring inside your walls. This can come into your house either overhead or underground, whichever way your electrical wires are also brought in. There are no EMFs from this path.

Once that signal gets to the modem, which is inside your house, the telco delivers its signal to televisions throughout your house one of three ways. The first is through Ethernet cables. The second is through the existing coaxial cable network in your walls, and the third is wirelessly through Wi-Fi. We, of course, recommend either of the first two methods.

That signal is carried on an Ethernet or coax cable from the modem to a set-top box next to each TV. An HDMI cable would then send the video and audio signal up to the TV. That takes care of channels you normally watch today on cable (which, the telephone company now also offers). Again, no EMFs there.

TV Signals Sent Around the House by Cable Companies

Let’s turn to the cable company. They provide television service directly through the coaxial cable network in your walls. They bring their television, Internet and telephone signal to the house over their overhead or underground coaxial cable to their network interface box on the side of your house. This spreads the TV signal to television sets throughout the house through a simple splitter to the network of coaxial cables in your walls. You simply screw in a coaxial cable to the jack in the wall of the room where you want your TV and run a coax cable to a set-top box. From there, you run an HDMI cable up to your TV for audio and video. If you need television in a room that does not have a coaxial cable jack, the cable installer can run a cable to that room either outside, or in the attic or basement/crawl space, or along the baseboards.

The only EMF implication from cable TV is that the coaxial cable coming from the street or utility pole to your house can sometimes carry current on the outer metal sheathing inside the cable. This causes magnetic fields inside the house along the path of this incoming TV cable and its grounding cable.

This happens because the incoming TV cable, whether overhead or underground, is grounded both at the house and at the street to the electric utility ground. This provides what we call a parallel path for return neutral electric current to flow back to the neighborhood electric utility. Since this TV cable is a singular metal path without another wire running next to it with the same amount of current flowing in the opposite direction, the magnetic field around the cable is not cancelled by another wire near it with the same amount of current, as is the case with properly wired electric circuits in walls.

This current on the TV cable, when present, is easily rectified by the insertion of a cable ground loop isolator for $15. I discuss this in more detail in my Magnetic Field EMF article, accessed from the Articles on EMFs page.

TV Signals Sent Around the House by Satellite TV Companies

Satellite television is likewise delivered from a rooftop or pole-mounted dish to a decoder box. That box then sends the television signal to set-top boxes throughout the house using the existing coaxial cable network in the walls. The installer can run a coaxial cable to a room that does not have a cable jack, similar to the cable installer. You then run an HDMI cable from the satellite TV set-top box up to the TV.

These days, however, satellite TV companies use set-top boxes throughout the house that get their TV signal wirelessly using units made by the Ruckus company and other manufacturers. I have seen these boxes, and they send out a Wi-Fi signal even when on standby and the TV set is not on. I have not found a way to disable the Wi-Fi on these boxes, and this is for regular TV, not Internet-delivered TV content.

So, for that reason, I recommend that people not sign up with satellite companies that use set-top boxes that communicate wirelessly. If the satellite TV installer says he can use boxes that can get their signal through the coaxial cables in the wall and he can disable any Wi-Fi, then you can use satellite TV. However, even when installers say they have disabled Wi-Fi, you must always measure for Wi-Fi yourself with a radio frequency meter. See EMF Meters and Instruments on my website.

The Age of Internet-based TV

After having considered the EMF implications of getting regular TV to your television sets throughout the house, now you want to stream your favorite TV shows or movies through Netflix, Hulu, HBO Go or a hundred other new ways to get TV content. That comes from the Internet, not from the TV cable or over-the-air. It requires a connection to the Internet through your modem, which you must establish with your provider. You would have already done that for your computer. The question is, how will you get that Internet signal from your modem and router in your home office to the box that decodes the Internet signal and provides content to your television set in the family room?

That can be done through the set-top box of your cable or telephone company (whichever provides TV service to your house). Also, many newer TV sets come Internet-ready. You simply plug in an Ethernet cable and find the selection of Internet channels by changing the Source button.

You can also buy an Apple TV, Roku or Blu-ray box to provide Internet-delivered TV content to your television set. Each choice has slightly different offerings, pixel sizes and other features that set them apart from each other.

Each of these devices can get its signal either through an Ethernet cable or wirelessly through Wi-Fi. When we want to avoid radio frequency EMFs, we must disable Wi-Fi transmitters at both ends, since these devices talk to each other through two-way communication. Plugging in an Ethernet cable does not in and of itself disable the Wi-Fi, except in a few important cases.

The question for us with Internet-delivered TV always is, can we plug in an Ethernet cable and disable the Wi-Fi signal? If so, how? If not, how far does the signal extend in the room and how do we protect occupants from radio frequency EMFs?

Disabling Wi-Fi on Earlier Models of Apple TV, Roku and TV Sets

It turns out that earlier models of Apple TV (1 and 2) had the handy feature of having the Wi-Fi signal completely shut off when we plugged in an Ethernet cable and synched up the unit with the router. The same thing happened when we plugged an Ethernet cable directly into earlier models of Samsung's TV sets. All models of Roku also do this (however, there are important steps you must now take to render newer Roku models safe--see below).

I would always verify this by having my RF meter turned on as I do this re-configuration. When the Ethernet cable was plugged in and the device or TV set synched up with the router, the Wi-Fi signal went away and stayed off.

Newer Models Don't Easily Allow This

However, these companies have changed their technologies on newer models so we can no longer disable Wi-Fi as easily. Apple TV 3's have Airplay that we can disable on-screen, which shuts off the continuous Wi-Fi signal, but I still pick up an occasional RF signal every minute or so. You have to verify this for yourself. Apple TV 4 doesn't even shut off the WI-Fi when you disable Airplay on-screen. There is also no setting to disable Wi-Fi on-screen for newer models of Samsung's TV sets.

Regarding later models of Roku, the Wi-Fi is still disabled when you plug in an Ethernet cable. You must wait long enough for the Roku to recognize the Ethernet cable once you plug it in. It can take a minute or two before the Wi-Fi stops broadcasting and the device is getting its Internet signal over the Ethernet cable.

On the Roku 3, it will continue to broadcast a second Wi-Fi signal when you plug in an Ethernet cable even though it is now getting its Internet stream over the Ethernet cable. This Wi-Fi is from what is known as Wi-Fi Connect (also known as "screen mirroring"). You can disable this in the General Settings of the on-screen Roku prompts. Wi-Fi Connect allows you to stream directly to the Roku unit from your smart phone. You would be giving that up to not have any Wi-Fi emitting from the Roku device.

You can also swap out the Roku remote control with an infra-red (IR) model, because the Roku remote provided with Roku 3 communicates with the Roku device using radio frequencies (RF) only. That signal from the device in your hand is strong. Contact Roku to purchase an IR remote control for a Roku 3. Take the batteries out of the RF model remote, so it does not continue to transmit when you put it in a drawer.

Another option to stream Netflix, Hulu and other Internet-based TV content is the use of a Samsung Blue-ray player. You can plug in an Ethernet cable and run an HDMI cable up to your television set. The Wi-Fi on the Blue-ray can be disabled using the remote control through on-screen prompts on your TV set. Go to Network and choose Hardwired. That will initiate a process where the Blue-ray player will synch up with your router over the Ethernet cable. Use a Network Adapter to get an Ethernet cable into the room with the TV set if the router is not in the same room or you don’t already have an Ethernet jack in the wall.

Order a certified refurbished Samsung Blue-ray player at Amazon for $42 by clicking here.

New flat screen TVs, which have virtually no magnetic field EMFs (as the much older cathode ray tube TV sets did), are Internet-ready and come pre-loaded with Netflix, Hulu and YouTube. Up until recently we have had the ability to disable the Wi-Fi on Internet-ready flat-screen TVs when we plugged in an Ethernet cable and used on-screen prompts to set the TV to connect directly to the router via a hardwired connection. (You can use a network adapter to bring hardwired Internet into the room where the TV is located—see the Radio Frequency EMF section of the Safer Use of Computers page for details).

However, the most recent Samsung TVs have the annoying drawback that the Wi-Fi does not turn off when you connect an Ethernet cable and set the TV to Hardwired Connection rather than Wireless on the Network option under Settings. The Wi-Fi signal continues to emit from the TV even when it is turned off (which is only standby mode for the electronic components within the TV).

Fortunately, the signal strength of the Wi-Fi transmitter does diminish in intensity with distance across a standard living room but if children play on the floor in front of the TV or you are electrically-sensitive, you can either plug the TV into a power strip and flip that off when you don’t watch TV (which kills the Wi-Fi transmitter) or you can look for an older model Internet-ready flat screen TV through Ebay and purchase a radio frequency detector to verify that the Wi-Fi has been turned off when you connect an Ethernet cable and select the hardwired network on the TV’s on-screen prompts. Another option is to disable the Wi-Fi transmitter inside the TV, if you are handy with a screwdriver, as discussed in the next item.

Disabling Wi-Fi on a TV Set

There is a YouTube video of an individual who opened up the back of his Samsung TV and found the Wi-Fi module. He unplugged the wire to it, which disabled the radio frequency signal. That, unfortunately, voids the warranty of the TV set. However, if you follow his directions carefully and don't damage the TV in the process, you should be fine (but don't take my word for it. If you undertake that process, you must understand that you are doing so at your own risk and that I am not responsible for any damage or lack of operation that occurs). The YouTube link is here.

Monitoring Wi-Fi from Apple TV, Roku and TV Sets

I have measured the RF signal at normal viewing distances across the room, and it was below 100 microWatts/meter squared. That is tolerable for most people, but EHS people need the Wi-Fi to be off completely. That Wi-Fi signal continues to emit into the room even when the TV is turned off (which is really, standby mode). You should plug the TV into a surge protector and then flip that off when you don't watch the TV, so you don't have any RF EMFs in the room when the TV is on standby mode.

With any TV model you buy, you should plug in an Ethernet cable and go into the settings under Network and choose Wired Connection. The TV will synch up with the router and you will have access to YouTube, Netflix, etc. You then need to check that the Wi-Fi signal is off with your RF meter. If so, congratulations. If not, either find another TV set and keep checking with your RF meter or use the strategies I mention above.

If you use Apple TV, you can try older models 1 and 2, available on eBay. I cannot guarantee that every model shuts off Wi-Fi when you plug in an Ethernet cable. That is what I found with the models I tested at certain clients' houses, and I have successfully disabled the Apple Play on an Apple TV model 3.

With Roku, as mentioned above, the Wi-Fi will shut off when an Ethernet cable is plugged in, particularly if you wait long enough, however, there are steps you must take, as outlined above, to make sure it is completely disabled.

Ultimately with any of these models you must always check for this yourself with your own RF meter.

If the telco or cable set-top box provides Internet TV, make sure the installer disables the Wi-Fi on the set-top box and verify that with your RF meter. If it cannot be disabled, have him replace it with a box that does not have Wi-Fi to begin with. If you are successful at disabling the Wi-Fi, you will still need to go into the TV set's Settings under Network and select Hardwired Network. Then verify that the TV itself is not sending out a Wi-Fi signal with your RF meter.

Additional Ways to Reduce or Eliminate Radio Frequency EMFs

If you must use a Wi-Fi transmitting Apple TV or Roku unit, you can wrap it in a couple of layers of radio frequency-shielding fabric, such as Argenmesh. Argenmesh always comes five feet wide and is sold by the foot. One foot of Argenmesh sells for $17 from LessEMF, available here. Two layers of Argenmesh will reduce the RF signal quite well, however, if you are EHS, you don’t want to use this option. Make sure the device you are wrapping does not run hot, as you don't want to trap heat in an electronic device that generates heat.

One other option is a Blu-ray player, which now also provides Internet TV. Connect an Ethernet cable to the Blu-ray player and then go on-screen on your TV set under the Blu-ray settings and choose Hardwired. I have verified that the Wi-Fi is fully disabled on a Samsung Blu-ray Disc Player/DVD Player, model BD-JM57C (Fully Refurbished). It is available from Amazon for $40 by clicking here.

How to Get Internet over Ethernet Cables to TV Sets

You can get Internet service through an Ethernet cable to a room that does not already have it through various hardwired ways. These options are covered in the article, Safer Use of Computers on my website. That is how you can get an Ethernet cable to your TV set for Internet TV when the TV is in a room some distance from the router.

I have been told by a telco installer that his company's U-Verse equipment does not do well when MOCA (Multimedia Over Cable Alliance) units are used. U presume this is also true of FIOS. MOCA is one of the options you can use to get Internet to other rooms in the house.

To get Internet to your TVs, it is best to hire someone to run Ethernet cables outside, in your attic, basement/crawl space, or around baseboards. Next best, but more affordable, is network adapters. I use a Network Adapter, and even though the speed indicator is red (<50 Mbps), not yellow (50-80 Mbps) or green (>80 Mbps), I am still able to stream Netflix on a TV that is in a room some distance from the router. This is all covered in my Safer Use of Computers article.

Other Forms of EMFs from TV Sets and Remotes

Also, TVs in the old days used to emit horrendously high magnetic field EMFs many feet into the room. I have measured high magnetic field EMFs extending up to 4-6 feet into a room in all directions, including right through a wall, from old model cathode ray tube (CRT) television sets. This is also true of older computer monitors, which were also CRTs (also known as a video display terminal, or VDT).

Newer flat screen TVs and computer monitors have a very small magnetic field, particularly the liquid crystal display (LCD) and light emitting diode (LED) TV sets. The magnetic field from these models do not extend more than 6-8 inches from the TV set, in most cases.

Some plasma TV models can have magnetic fields that extend a bit farther, but still not as far as the older CFTs. I do understand, however, that plasma TVs consume a great deal of electricity and they also generate a fair amount of so-called "dirty electricity."

Finally, regarding TV remote controls, they can connect to the TV set in one of two ways, infra-red (IR) or radio frequency (RF). We recommend the former. You can actually program the remote to operate in one or the other mode.

To determine which mode your remote is operating in, turn the TV on. Then hold the remote in one hand face up with the top of the remote pointed at the TV, as if you were going to change the channel. Cup your other hand over the top of the remote (pointed at the TV) and see if you can still change the channel or volume. If you cannot, the remote is operating by infra-red, which is safe (for most people). The remote sends out a beam of invisible light in the infra-red range, which is picked up by an infra-red eye on the front of the TV set.

If, on the other hand, you can change the channel and volume with your hand cupped over the top of your remote, it is communicating by radio frequency (RF) signals. This means, whenever you press any button, you are exposed to a blast of RF signals from the remote. You can re-program the remote to communicate by IR instead of RF.

Then, re-check the operation of the remote to make sure you cannot change the channel and volume with your hand cupped over the top.

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