Can ham radio interfere with LTE wireless internet signal?

I know that there is another thread that asks a similar question however the questioner there had DSL internet, so I think my question is sufficiently different to warrant a new thread.

I have wireless internet service using LTE signal. I have had constant problems for several years. The tech from the ISP was here AGAIN last week and is throwing up his hands not knowing what to do. His report to his boss is that ‘the signal sucks and there’s nothing he can do about it’. He says that other customers several miles away have ‘great signal’ and that our stretch of road and the adjoining road was a ‘black hole’.

I am not a techie…just trying to figure out this mess so my kids can do their online school!

A neighbour who lives about 500m away at the corner of the adjoining road is a ham radio operator. He has been there for years. It just dawned on me tonight that maybe his equipment was causing interference with my LTE signal. So searched and came across this site. Nice to meet you all :)

I believe that this is the info on my LTE system.

Frequency 3615.0 MHz

Bandwidth 20 MHz


The SINR number for my signal is inexplicably VERY low (0-2 and even sometimes -1) indicating high level of signal interference. I'm led to understand that this should be up higher than 12 or 13, preferably 20.

QUESTIONS

1. So is it possible that interference from the ham radio is the source?
2. Is it possible that the signal from the ham radio is aimed in a certain 'direction', or is it 360deg?

I understand from the discussion on 6887 that it's not the ham radio operator’s ’fault’ and that the wireless internet equipment should filter interference out, and it may not be doing what it is supposed to be doing.

If you need more info to help answer, please let me know and I will edit the question to make it more complete.

Any assistance is appreciated!

Phil

• Nothing personal - Philip is asking very politely, but I find this thinking very unfortunate! Radio amateurs make up nearly 0.2% of the US population, so I guess >20% of people live within 500 m of a ham. Most people use LTE in some form, and many of them are unhappy with their signal. This means there are potentially 10 million people in this situation - poor LTE signal, within 500 m of a ham with all those antennas poking out. There must 10,000 RF transmitting devices within 500 m of you. Of those, the HF radio is the least likely to be the problem. Dec 8 '20 at 15:04
• Also, not that it helps you much, in cities and dense suburbs, cell phone base stations will be 1 or 2 km apart, so coverage will vary quite a lot over a few miles. Where I live we have terrible signal precisely because people are scared of cell phone towers and refuse to have one put up nearby. Well-connected people can get the proposals squashed, I heard first-hand about the drama of the much-needed mast being cancelled by the neighbourhood. Now of course our phones are transmitting on maximum power all day, so more RF if that worries you, shorter battery life and slow data. * sigh * Dec 8 '20 at 15:12
• In my ham radio club, we have a member who used to be a technician for the FAA, who made a living solving problems similar to yours. This ham has the necessary technical equipment (a spectrum analyzer), and he voluntarily helps people who ask nicely. You might consider contacting your local ham radio club and asking for help, since you have such a worthy cause; maybe the local club in your area has an expert like my club does. Dec 8 '20 at 17:29

the short answer to #1 is that it is possible but not at all likely for the same reasons Kevin outlines in his answer to the question you linked to, especially the fact that almost no ham radio operators transmit continuously... only when actually having a conversation, and only when it's our turn to speak in the conversation.

Answering #2, the directivity of the ham's signal: it depends on the antenna. If the antenna he has is just a wire or pole sticking straight up in the air, it's pretty close to 360° even. If it's any other configuration, it's stronger in some directions and weaker in others.

A note regarding interpreting your measured signal to noise ratio (SINR), it may indicate a higher noise floor where you are OR a lower signal from your carrier. Without measuring the noise floor and signal strength separately at a location that "works," it's difficult to understand what's "really" happening.

It may be (likely is) that the antenna configuration & power from your service provider in your direction is just not strong enough for the service level expected. Or perhaps your antenna is either misconfigured or not the most appropriate for service operation... this seems especially likely given your comment below re immediate neighbors' service level seems good with their antennas.

Finally: go introduce yourself to the ham! Many of us LOVE figuring out stuff like this. It may be that he even has the equipment to measure your signal issues and help diagnose and get to a solution.

BEWARE: you may become interested enough to get a license and pick up a fascinating new hobby... if that happens, we'll be here to welcome you in :-)

• hey guys...thanks for the welcome and appreciate that you see that I was trying to be as polite as possible. Not trying to imply blame to the ham. To be honest, after reviewing this with the ISP tech late last night, we feel it is highly unlikely that the ham interference is the problem. We did note though that my 2 neighbors (within 50m of me with same ISP but different antenna syle on a different frequency - 3565MHz) have very good signals with SINR values of 17 & 21 respectively. So it appears that 'something' is interfering with the frequency that my particular antenna is using. Phil Dec 8 '20 at 18:26
• First it's the road that's a "black hole", but then the neighbors are fine. It sounds like the problem is just at Philip's house. That makes me wonder how competent the ISP's technician is. Did he or she try another antenna, or test the cable, or swap out the LTE device? (I'm speaking rhetorically, I don't expect Philip to take notes on what the technician does.) Dec 8 '20 at 23:43
• rclocher3 you make a good point. 1) I have asked the ISP to come install the same antenna my neighbors have. Mine was supposed to be an upgrade compared to what they have but I call B/S on that now. 2) I will be challenging the tech to explain the signal interference on the one freq vs the other. Dec 9 '20 at 0:16
• It's also possible the house is in a hole, at a lower elevation, etc, or just enough further than the neighbours to not have enough signal from the tower. Dec 10 '20 at 6:09