My internet provider is telling me that an antenna on my neighbor's house, which he called a ham radio antenna, is interfering with my DSL internet signal. I'm not tech savvy at all, beyond what's necessary to function in today's world, so I'm clueless as to what this is, what its used for, or if this even a legit accusation.

I am, however, skeptical of this claim due to an ongoing history with my provider. I experience a problem about once a month, I call, they say they'll send someone, then after the call the problem clears up a few minutes later and their "tech" guy never even shows.

But this time its gone on for a week. We've replaced the modem and this is the explanation they're giving me. I feel its more likely that my provider is taking advantage of me, but I can't be sure.

Is it possible that this antenna could be interfering with my internet signal? And if it is the likely factor, is there some way for my neighbor and I to both have what we need? Or is someone going to have to compromise? I don't know this guy, I don't know what he used the antenna for, but it hardly seems fair for me to ask him to take it down or stop using it. He has rights just as I do. But at the same time, this problem is interfering with my livelihood. My job requires that I have internet access at home. If this problem persists, I'm super screwed.

Can anyone here offer up some advice? And please, I'm an idiot when it comes to techie stuff. Please dumb down your language enough for me to grasp what you're talking about. Ya know.. Use laymen's terms for me.

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    It would be helpful if you edited your question to include a couple pieces of information: • What type of internet service you have (cable, DSL, microwave, …) • A photo of the neighbor's antenna so we can identify the type and frequency range. – Kevin Reid AG6YO Nov 27 '16 at 20:57
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    Test by wiring a compute directly to the modem. That will make sure the problem isn't the WiFi between your router and your computer. – David Schwartz Nov 27 '16 at 23:15
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    A photo of the antenna would be really helpful in this case. Failing that, a good description of its physical size and what it looks like. (Does it look like a TV antenna, a simple straight length of wire, a vertical stick with some metal sticks protruding from it, or what?) Most likely if it's big enough to stand out, it's a directional short wave (tens of megahertz) antenna, or possibly one for slightly higher frequencies (up to a few hundred megahertz). – a CVn Nov 28 '16 at 5:54
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    DSL is wired so should be largely immune, and WiFi works in the thousands of megahertz range so direct interference is unlikely. There are requirements on amateur radio equipment about emissions on unintended frequencies, and those are rather stringent. That said, some cheap electronic equipment does deal poorly with powerful RF (radio frequency) fields. The good part is, that kind of RF interference tends to be somewhat easy to remedy without making any invasive changes to the equipment. (Ever seen those "bulges" on e.g. USB or power cables? That's their purpose.) – a CVn Nov 28 '16 at 5:58
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    As a general rule of thumb, it's always the ISP's fault until proven otherwise. In this particular case, it's definitely the ISP's fault even if it's your neighbor's fault, because FCC regulations require their devices to be able to tolerate RF interference, so if the ham radio is interfering with it, the ISP isn't keeping up their end of things. – Mason Wheeler Nov 29 '16 at 15:34

13 Answers 13

Could be, but likely not. In particular, almost no amateur radio station would be operating continuously, so if you have a problem that is not intermittent, that's unlikely to be the source of it.

(If you edit your question to specify what type of internet access ('cable', DSL, microwave link…) you have, and include a picture of the antenna, we can make a more informed guess about whether they might interfere. If they're on completely different frequency bands, well then.)

Talk to your neighbor. Don't lead with a complaint — just tell them that this is what your ISP is claiming and you want to get more facts. Have them tell you when they're operating (transmitting), or you tell them when you're experiencing connectivity problems. If the timing doesn't match, then this can't be the cause. (Also ask them what “bands” they are operating on and write down the answer.)

If the timing does match then things are more complex, because there could be several different situations:

  • Your in-home networking equipment (modem, router, WiFi AP) can't tolerate the nearby signal which it should be able to.
  • The ISP's equipment not in your house can't, ditto.
  • The electronics are fine but the cable is damaged somewhere (for cable-type internet access), letting the interfering signal in.
  • Your neighbor's equipment is transmitting excess power on frequencies which it shouldn't.
  • Your stuff is legal and functioning correctly, their stuff is legal and functioning correctly, but they're just too close together. In this case you'll just have to see if your neighbor can agree to avoid operating when you're working.
  • Oh I'm sorry... See? No idea what I'm doing when it comes to this stuff. My internet is through the phone company so I assume that means DSL...? Im not at home today so I can't get a photo just yet. But I can see if I can find a pic of it online. – Vanessa Nov 27 '16 at 22:03
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    @Vanessa Please edit your question to include the additional information instead of putting it in comments. – Kevin Reid AG6YO Nov 28 '16 at 2:41
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    @TheGreatDuck Both places is fine; comments only is not. Comments are ephemeral and for the purpose of improving the post they are commenting on, not for containing the information that post should have. – Kevin Reid AG6YO Nov 28 '16 at 17:32
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    My internet is through the phone company (Verizon) but it's fiber-optic (FIOS), not DSL. Like others here, I think it's possible, but unlikely. I'm a former ham and the power-levels and frequencies hams typically use are very unlikely to cause interference to internet service, but it cannot be perfectly ruled out without knowing more information. I would talk to the ham-radio neighbor - most hams are geeky and curious and community oriented so would probably not take offense, and might even enjoy helping track down the problem. – user316117 Nov 28 '16 at 21:36
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    @Vanessa The idea is to edit all additional facts into the question so that anyone coming to the page later does not need to read any of the comments — the “conversation in the comments” should be for working to create the question and answer in their best form, not for containing them. You added "DSL" and that's the right idea; you also wrote comments like "The devices use at any given time are wireless. …" and those should be put into the question. No apologies necessary, it can be a tricky idea. Thanks for coming back! – Kevin Reid AG6YO Dec 1 '16 at 20:19

A "ham radio" is typically a transmit/receive system that uses certain frequencies set aside for radio amateurs to communicate with other enthusiasts. If there is a big antenna on your neighbor's roof, he/she is likely enthusiastic and quite knowledgeable in the area of radio interference; I am going to guess he/she would be happy to help you troubleshoot.

Interference between your neighbor's activities and your internet signal can happen if the frequencies of the transmitter and the frequencies used by the internet provider are close enough together; and if there is some way for those signals to "mix". This can be a result of poor shielding, damaged cables, or just plain bad luck in the layout. It can also happen if your internet signals are traveling "over the air": this can be because you have a satellite link, or because you use WiFi inside your house to go from the modem (the device that connects your house to the internet) to your computer.

In my experience, WiFi interference is much more likely between WiFi routers in adjacent homes, than between a WiFi router and a ham radio.

Talk to your neighbor. Bring cookies.

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    I like your advice. I'm not "neighborly"... Have no idea how to be neighborly. I will take treats. Maybe even if its not his antenna, which I suspect is the case, he can help me figure out how to deal with my internet provider when they try to tell me again that its outside interference. Hard to argue something when you have no idea what you're arguing! Thanks! – Vanessa Nov 28 '16 at 0:25
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    "Hi. My name is Vanessa. I see you have a big antenna. I bet you are good with electronics. I have this weird problem with my internet, and the ISP says it might be something in the neighborhood. Do you have problems with your internet? Oh - and do you like cookies?"... – Floris Nov 28 '16 at 0:34
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    Or even "Hey, nice to meet you! I'm having trouble with my internet, and my provider is trying to pass it off on your antenna. Could you help me prove them wrong? I have cookies!" – Alan Shutko Nov 28 '16 at 18:08
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    +1 for the first paragraph, -1 for the second. "Uses radio waves" does not equal "is wireless." Nearly all forms of Internet connections use radio-frequency signals ("radio waves") and a wireless transmitter certainly can cause interference to a wired system. I agree that that's mostly likely not the case here, but it's certainly very possible, especially with a DSL system. DSL is just an RF signal transmitted over a phone line instead of over free space. Since phone cables aren't shielded all that well, an RF signal with enough power will leak onto the line and could interfere with the DSL. – reirab Nov 29 '16 at 5:02
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    Similarly, cable ISPs (as well as cable TV transmissions) are also just RF signals broadcast over a wire. Just, in the case of cable, the carrier frequencies used are in the hundreds of MHz or GHz and they use decently-shielded coax cable instead of dinky 2-wire or 4-wire phone cable. DSL uses much lower frequency carriers, even down to the hundreds of kHz or less, making it much more susceptible to interference from a ham operator than cable would be. With DSL, all of your home phone cabling can be acting as a big antenna for picking up RF interference. – reirab Nov 29 '16 at 5:13

A HF transmitter can interfere with a DSL service if the conditions are right simply by inducing more RF on the drop wire then the DSL modem (Which always cheap out on front end electronics) can cope with.

Been there with my own DSL service when running a few hundred watts on 20M, suitable ferrite rings on the power and data wiring can sometimes help, but I would expect such problems to be intermittent (Most Hams do not transmit 24/7).

Go and talk to the neighbour, most hams are well aware of the potential for this kind of thing, and while (at least in the USA) it is not really their responsibility to fix your inadequate networking gear, they will often try to help in order to keep the peace.

Testing to find out if his rig is the problem is easy with your cooperation, and you may well find that his station has nothing to do with it (Convincing the phone company 'technician' of this is left as an exercise in frustration).

This really is the ISPs problem, not the radio operators, but having dealt with ISP support departments, you are more likely to get a fix from the ham (Who, apart from anything else, can sometimes point out to the ISP where their problem is)!

From a legal perspective, the modem is almost certainly a "class B computing device under FCC part 15", which means that it must accept any interference from a licensed radio station. This is to say that a licensed station is allowed to cause it interference. Good networking kit will have better protection, but the stuff most ISPs supply as freebies is 'designed to a price'.

Actually, depending on the power of the station, it could very well cause problems with any electronic equipment. I ran into a situation once where a band I supplied the sound system for had constant interference when playing one particular club. One night I was so bad we were actually getting the Ham's entire conversation through the PA. We powered down to avoid any possible damage while we figured out what to do, and we could still hear noise. His rig was so powerful, it was actually able to move the speaker coils with the stray RF the cables were picking up. Luckily, when we found the (huge - looked like the Eiffel Tower) antenna a half block away, we talked to him and he was shocked. He shut down (he had been talking to someone in Kowloon) and the band was able to play. I never found out what he did to modify his gear, but we never had a problem there again.

I'm a tier 3 network support tech at a major Canadian ISP. Ham radio interference is a disturber our systems actually specifically check for, in relation to ADSL2+ and VDSL signals, and I've seen cases where line errors appear to have been caused by the client's own antenna. It's possible that whoever you're talking to for tech support has access to similar software listing the line disturbers.

Just about anything that produces a strong enough RF field can induce current in the phone lines, causing errors. For example - we used to have an issue with treadmills next to phone jacks causing similar problems.

Short answer: Based on your description of the scenario, it's possible, but seemingly unlikely, that interference received from the ham radio is causing your problems.

Longer answer:

Kevin's answer is good (especially his recommendation to talk to your neighbor and get his input,) but I just wanted to add a few things regarding the technical aspects involved in answering your question:

General Background on RF Communications and Hams

Most forms of home Internet connections use RF (radio-frequency) signals to transmit the data, regardless of whether that's over a wire or over the air. This is true for DSL, cable, and any currently-popular form of wireless ISP. The only major exception to this is fiber-optic ISPs, which use light signals instead of RF signals (but even those could potentially have RF equipment in the transceivers, that is, in the modem.)

Additionally, home networks use RF signals to transmit information (i.e. Wi-Fi, Bluetooth, and even wired Ethernet.)

All forms of RF communication, whether wired or wireless, operate in some frequency band. In most cases, only signals (whether intentional signals or unintentional ones like harmonics and spurs) in or near the operating band will cause interference with a given communication system. The frequencies of these bands are measured in Hertz (Hz.) 1 kHz = 1,000 Hz, 1 MHz = 1,000,000 Hz, and 1 GHz = 1,000,000,000 Hz.

Ham radio operators broadcast signals on frequencies ranging from around 135 kHz up to around 30 MHz. This is relatively low compared to most modern RF communication.

Potential Effects on Different Types of Internet Connections

Here's a rough guide to how different networking and Internet connection technologies work, including which frequency bands they use and how they could be affected by a ham operator:


DSL ISPs typically use quite low frequencies, in the kHz to the tens of MHz. Notice that this is the same general region of the spectrum used by ham operators. Furthermore, DSL operates on normal home phone cables, which are not very well shielded because they were originally only designed to carry baseband voice signals which only go up to a bit over 3 kHz. Because of this poor shielding, all of the phone cables in your home can act as a big antenna and receive any radio signals that are being transmitted over the air nearby at high enough power levels.

As such, it's actually quite possible for a ham operator who is currently transmitting enough power in the direction of your home to interfere with a DSL signal enough to cause high packet drop rates or even total connection loss, especially if your phone lines and/or DSL modem aren't shielded well (which they probably aren't.)


Cable ISPs typically use much higher frequencies in the hundreds of MHz up into the GHz. These signals are then transmitted down a coaxial ('coax') cable that is usually shielded pretty well. Since the cables are shielded reasonably and the frequency bands are quite far from those used by hams, it's very unlikely that a ham's operations could interfere with a cable Internet connection unless the ham radio was sitting right beside the cable and/or modem and transmitting a high amount of power.

Wi-Fi, Cellular Data Networks, et al.

Wi-Fi, Bluetooth, and other relatively short-range data networks generally use either the 900 MHz band, the 2.4 GHz band, or the 5.8 GHz band (and some newer equipment uses 60 GHz.) Cellular data networks generally operate from around 800 MHz to around 2.2 GHz. As such, these networking technologies all operate in frequency bands quite far from where hams broadcast. That said, unlike wired technologies, these technologies are intentionally designed to receive signals that are broadcast over the air. Due to the short length of their antennas and their receiver designs, they will not pick up signals in the ham bands well, but they will pick them up somewhat if there's enough power being broadcast.

As a result of these factors, these technologies will be significantly more susceptible to interference from a ham transmission than a cable connection would be, but probably not as susceptible as a DSL connection. A ham radio transmitting close to a Wi-Fi station could take it down, but probably not one at your neighbor's house unless he's really aiming a lot of power at you.


As other answers have suggested, it's quite possible for ham radio transmissions to interfere with a DSL signal. If your Internet connection is cable, though, then the tech who suggested the ham might be the problem was probably smoking something. That said, the patterns you've described for the behavior of your Internet connection suggest that, even if you are using DSL, it's more likely a problem with your modem or ISP, as it's unlikely that your neighbor is transmitting all day long.

If you do use DSL, there are a couple of ways to go about confirming or denying whether your neighbor's ham radio is the source of your problems:

Talk to Your Neighbor

As others have suggested, talk to him. He'll probably tell you when he's been transmitting and the patterns of his transmit times either will or won't line up with when you've been having problems.

Use a Spectrum Analyzer

Another possibility is to use a spectrum analyzer to check out the signal integrity and look for possible interfering signals. Honestly, the tech who visited your house really should have already done this in attempt to diagnose the problem. The cable techs who have been to my house in the past have indeed hooked the line up to a handheld SpecAn to check out the signal. If you have a friend who happens to be an electrical engineer (especially an RF engineer) or an RF or ISP tech, they might be willing to bring one over and hook it up to your phone lines to see what the relevant portion of the spectrum looks like. This should pretty definitively tell you whether the problem is due to an interfering signal or not. If it is due to an interfering signal, you could hook the SpecAn up to an antenna designed for the appropriate band and see if the problem signal gets stronger as you go toward your neighbor's antenna.

  • A bit of international perspective related to the cable comments. In my country, we have an analog cable tv channel whose audio carrier is right on the output frequency of a 2 m repeater channel. Leaky coax cables from bad cable tv installations can be heard from a distance of several hundreds of meters. Sometimes even people living close to the repeaters using the affected channel can even hear ham traffic from their TV sets. – AndrejaKo Nov 29 '16 at 13:16
  • I would take exception to the statement that "the ham operator is causing" the problems. It might be accurate to say that the symptoms are being caused by the radio transmissions, but usually in such cases the 'problem' is that the internet equipment (or phone line, or general wiring) is functioning incorrectly in the presence of a strong RF field that it should be capable of filtering out. – Scott Earle Nov 24 '17 at 2:35
  • Well said, Scott! As I have stated elsewhere: Almost without exception, every ham with neighbors has had the problem described in this old cartoon. It may be funny, but that's just the way it is. – Mike Waters Nov 24 '17 at 3:48
  • @ScottEarle Yeah, sorry, that was worded poorly. Fixed. – reirab Nov 24 '17 at 19:09

This may already have been suggested to you, but if you log the dates, times & duration when the problems occur & politely ask your neighbour to do the same when he/she is transmitting (this will normally be required by a ham anyway if such issues are observed), I feel certain that he/she will be happy to do so & compare both your & his/her data after suitable period. It highly unlikely that if the ham is not transmitting, then no interference should be found and only at those times when he/she is transmitting would issues happen. Best of luck with your attempts to stop this and as a ham operator myself, I (in line line with my conditions of license) would be happy to help out & resolve any potential problem that I may (or may not) have with my neighbours.

Barring what the other answers already advised, which things are giving you trouble? Wireless devices such as tablets and laptops or wired devices such as a desktop computer? If it is only the former then the ISP is blowing smoke. The modem controls the signal coming into the home and into fully wired devices. The router projects that signal into the air for wireless devices to pick up on. If the latter has trouble but not the former then it is either your router, wireless device, or the antenna causing trouble. If the former is true, then the ISP is being an idiot altogether like usual business.

A common thing with ISP's imo is that they will never say "it was our fault, sorry.", because it makes them liable for you losing connection. Note: you cannot sue for damages afaik, but you can technically sue them for failing to provide service if they do it enough. So, they will do whatever it takes and jump through whatever hoops they can to deny failing to provide service. Also, ask your neighbors if their internet is down. One time we had no internet for almost two weeks because the station went out at the corner and "it's working fine. It's your fault and your 20+ neighbors. I won't say names of companies, but let's just say they have a loooong history of bad customer service, bad internet service, and generally being a bad company. Next time you call them, ask for a manager. Trust me, if it's even remotely like the place we had... you'll get hung up on or put on hold indefinitely. Or they'll say all the managers are out of the office at a "funeral". (Yes, the rep claimed this then 10 minutes later the manager took the phone cause he saw the rep cursing at someone). Needless to say, this is how most customer service centers can be at times. It's not one particular place really. It's just how all places get after a while or can be when you get certain people on the phone.

I have this same problem at my house. Whenever I am using the HF bands, my DSL modem loses link, especially in the lower HF bands, and especially when I'm transmitting with more than about 300W. This is because the phone lines to my house are not well-shielded, and the energy from my transmitter couples into the DSL lines and overloads the modem.

I solved this with ferrite beads. Lots of them. I put ferrites on the phone lines to the house and the cable between the wall and my modem, and in a few other places along the phone line to the house. It eliminated almost all of my problems.

If someone with a CB or HAM using 500 watts to over 2000 watts..

(Also referred to as kW for Kilowatts) the pure power being transmitted can actually interfere with nearby DSL AND CABLE lines!
Particularly if the connections are not very solid. If the shielding on the particular cable line form the pole to the customer is not properly grounded or there is just very high power nearby, the RF signal can introduce quite a lot of "Noise" into the line and interfere with the internet signal. It does NOT have to be in the same frequency range as the power of the transmitted RF is high enough to simply interfere with the signal. Further evidence I had that this was the case was that my computers' wired Speaker system would pick up the neighbor's voice and he could be heard through the speakers as he keyed up high power. It would ALSO be picked up by my WIRED headphones that use a standard Micro USB cable! (10ft cord) It would cause havok with my computer as well. My WiFi network would drop and I would have to at times reset the routers and modem to get it back! So yes, a nearby high power HAM radio transmission can disrupt MANY different electronic systems. I will have to do research to find out if there are legal issues with it since the neighbor will not acknowledge he even uses the radio, but I recognize his voice coming over my speakers! Kinda hard to say you are not causing the problem when your voice is heard in the interference. Safe to say he's using very high power. As a tech for over 40 years and an ECM tech in the USAF, I have a background in radio and in interfering with signals! ;-) (However, such interference is NOT common. I seem to be dealing with an extreme case)

  • If you can understand his voice, chances are he's a CBer running AM, and not a ham. There are very few hams that use AM, especially in Midwestern USA. Most hams using high power use SSB, which cannot be understood. While many hams are legally allowed to run up to 1500 watts, CB is by law limited to about 12 watts. Usually, when hams interfere with home appliances, etc. like that, it's design deficiencies in those. The same could be said for CB IF they were allowed to run high power, but they are not. I think that it is likely that you might live close to a CBer running illegal power. – Mike Waters Aug 6 at 20:58

My answer doesn't have to do with antennas but with personal experience with DSL providers.

Did the "tech guy" check connections leading from their box in the street to your house or did they just throw their hands up and not even try?

I had problems with my DSL a long time ago too. I connected directly to the DSL modem (didn't use my wireless at all) and still had problems but my provider was giving me the run around, just like they did with you. I kept asking for someone to come out but they resisted. Finally, they sent someone out but kept reminding/threatening me that I'd have to pay a fee if they had to fix something inside my condo.

Luckily, the tech looked outside first and found out that something was CORRODED so the problem was from their box to the condo complex. The internal connection from the telephone room in the condo to my unit was fine. I don't know how different it is for a house but I think this is worth a try too.

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    wow. Ive seen tech guys claim they came out to a house and replace the modem when they never showed up and apparently went around back and fixed something that was the ISP's tech. Fun times. Fun times indeed. Good thing those people were "recording wildlife" that day. I.E. Checking to see if a tech showed up in secret. – The Great Duck Nov 28 '16 at 19:40
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    No, he's been here 3 times now, and has mentioned possibility of a "problem outside", but hasn't checked. He was here this morning actually. This isn't a problem coming from my neighbor. I've confirmed that. Its their problem, and I believe they know what it is. Someone knows something. Because of my history of calling them, them telling me they're sending a guy, the problem "fixing", and the guy never shows up (until the past week and a half). This morning I woke up, and the internet was fine. Tech guy showed up but...."all the numbers look good, I don't see a problem". How convenient. – Vanessa Dec 1 '16 at 19:19

Like the previous answer: I'm also a ham, and when I send on frequencies around 7 Mhz (power level<50 Watt), my ADSL connection drops. So yes: it is possible.

  • Hello and welcome to The format and the rules here are different than a typical chat-style forum. Please take the tour to get the idea. In particular we're looking for high-quality answers to questions. Your post doesn't answer the question. – rclocher3 Apr 9 '17 at 15:38

I'm in IT and deal with ISPs regularly. If you plug a computer into the dsl modem and turn WiFi off, and still have the problem, then it has nothing to do with anything wireless. This includes anything using an antenna like your neighbor's equipment. Ham radio is only, though unlikely, possibly going to interfere with wireless and only when transmitting which would be occasionally not constantly.

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    It could still be related to stray RF. It's a stretch, but the whole premise of what the OP's ISP is saying is a stretch to begin with, so... – a CVn Nov 28 '16 at 5:46
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    This is not true at all. Wireless systems most certainly can interfere with wired ones. DSL is actually probably more susceptible to interference from a ham due to the carrier frequencies involved. Wi-Fi uses 2.4 GHz or 5.8 GHz carriers. DSL uses carriers down in the low MHz and even hundreds of kHz, which is much closer to the bands where hams operate. Phone lines aren't shielded all that well, so they'll pick up power from a strong enough signal, even though they're not designed to intentionally do that. By the way, I have 2 degrees in CompSci and design RF equipment for a living. – reirab Nov 29 '16 at 5:23

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