HF interference on my ring main?

Discussion in 'Interference Problems' started by M6VWM, Apr 1, 2018.

  1. Ken G3SDW

    Ken G3SDW Moderator

    Matt i have copied your post here today to the EMCC as it is a sad state of affairs which someone should be able to help.

    I assumed that as i had not heard from you that G0NZI had sorted out your problem as you have said in the past that he knows all about problems such as yours and can sort it out, lets hope he comes back and locates it for you and your neighbour is a bit more cooperative as i still think from all you comments in the past that it is coming from them.
  2. M6VWM

    M6VWM Member

    Thanks Ken. Sorry probably sounding a bit despondent but it’s certainly been ups and downs.

    G0NZI has been amazing, the support and hardware he has loaned me to try and get me on air is humbling. I hope I can repay the kindness some day. His noise finding antenna is brilliant I’ve told him he should probably considering producing them. Be a handy device in today’s world.

    As you say ultimately the challenge is a social one. I need to get braver and ask if we can spend some time literally switching everything off and on again one by one.
  3. Ken G3SDW

    Ken G3SDW Moderator

    No Matt the other way round mate, mains off at consumer unit and if the noise goes then you can once the mains is back on turn things off individually.

    As for this antenna that G0NZI has made to locate noise then, and dont take this the wrong way, why have you still got the noise, surely using it will give you the exact location of were it is coming from.

    I will update you when i have some replies from other members of the EMCC.
    Last edited: Nov 22, 2018
  4. M6VWM

    M6VWM Member

    You may recall the copper pipes were radiating well they have now been earth bonded and hopefully aren’t radiating anymore.

    Should make it a lot easier now to trace a source we hope.
  5. M6VWM

    M6VWM Member

    He visited previously before the electrical work and earth bonding of the pipes
  6. M6VWM

    M6VWM Member

    Much to my surprise it looks like I’ve found the culprit and it’s not the tv.

    A Virgin media modem seems to be the cause , when plugged in s8 from 160m through 40m (20m seems clear at present) unplugged and all gone away.

    Do I simply call Virgin media and report it?

    I’m a bit in shock that we found it.

    Thanks,

    Matt.
  7. Ken G3SDW

    Ken G3SDW Moderator

    Yes and tell them you have been advised to get in touch with them.
    Well done.
  8. M6VWM

    M6VWM Member

    That was an experience, indian call centre so they've said they want to charge for a new modem. I stated its causing interference but as you can imagine as its not on script.

    I explained it as EMC and effecting my house also more simply as radio interference but she didn't seem to grasp it. She checked with a manager who also said I can pay for a new modem if they want one. Kind of disappointing.

    Should I say anything in particular? Or is there a particular department I should talk to? I'm a virgin customer and their support is a bit painful at the best of times haha.
  9. M6VWM

    M6VWM Member

    Interesting the adapter for the modem is creating S4 noise when connected and then when plugged into the modem itself it goes upto s8.
  10. M6VWM

    M6VWM Member

    I've just raised it via a complaint form as I couldn't get through the customer team, I'll let you know what they say.
  11. M6VWM

    M6VWM Member

    Fantastic they've upgraded the package, dropped the price and are sending a new modem. Can't say fairer than that. :)
  12. Ken G3SDW

    Ken G3SDW Moderator

    That make sense as then it will be connected to other cables which will re-radiate noise.

    Try and get to talk to a technical support department.
  13. Ken G3SDW

    Ken G3SDW Moderator

    Well done Matt.

    On reflection i think that you have had multiple issues and this one is the last one, which is good.

    How did Carl not find it with his antenna, it was under his nose and this is why i always tell guys to look close to home as it often is and by turning off the mains supply will prove it without any shadow of doubt.

    We got there in the end.
    M6VWM likes this.
  14. M6VWM

    M6VWM Member

    Morning Ken,

    So little progress report, all positive, still more to do. G0NZI is visiting today to help me have a tweak of antenna configurations and feed points to see if we can tie down the source of this noise. As I can only use 10w Im often below other folks noise too which after experimenting with other locals may be why I dont often get a response. We've tested the radio and tried a second one so we know the radio is good which is great.

    1. The new Virgin modem arrived and replacing it instantly dropped the noise I was seeing through the house.
    2. The heating pipes were not earth bonded as I mentioned, although things improved temporarily with an earth, they are still radiating noise at certain times. Switching off all the breakers bar the main one doesn't stop the noise however turning off the master switch does stop this sometimes, other times, not. I haven't spotted a pattern yet, very intriguing. An AM radio next to any copper pipe is extremely noise even from a short distance, with hot spots in corners for some reason. An electrician is checking the boiler wiring at the weekend and confirming the house earth is sufficient.
    3. Lampposts seem noise free but we will try again with a portable HF rig. We will also get a read from the garage on the back of my property.
    4. Sadly a second intermittent source has presented itself but I am feeling much more positive about solving it after the modem success. It is more on and off than the modem with a very specific set of characteristics but does seem to appear during leisure time. I think previously it was a combination of two, without the old modem the noise is more distinct.
      • Distinct frying bacon sound on 160,80, 40. 20m always tends to be clear through the day but noisy after 6pm. Noise on the other 3 tends to either be completely absent or S8/9, occasionally drops to about 5, this is day and night.
      • Used an Icom 7300 with waterfall to see if I can see a distinct pattern after watching the excellent RSGB video on EMC. Couldn't see a specific shape to the noise but I did notice a kind of rolling wave from left to right, very uniform. The Icom is much better at filtering the noise than my yaesu and does make hearing QSOs a lot easier, and response is already up due to better sound quality. I've had a few good rag chews on this rig on top band.
      • It occurred to me yesterday that it sounded worse when it started raining, may be a coincidence?
      • I wonder now if next door have a second TV, or a computer with a dodgy PSU in a bedroom or their conservatory perhaps they to have a dodgy virgin media modem like I did. Hoping to catch them tonight to discuss and test whilst G0NZI is around. Feels awkward asking to access devices in their house but if I can find the source Ill have beautiful operating conditions.

    Thanks for your continued efforts and patience, I was at rock bottom so sorry about the despondent response. Main points for me feel like the boiler although turning it off doesn't stop the noise, and the neighbours having a SPS somewhere we haven't considered. We are making progress, slowly but surely.
  15. M6VWM

    M6VWM Member

    I tried to think back and I suspect when he visited I just unplugged them all so that's why it wasnt picked up. With hindsight now some noise is back I should have realised it may come back. I think I could use a week off to just methodically work through this so I don't keep making these basic errors. :)
  16. Ken G3SDW

    Ken G3SDW Moderator

    Keep up the good work Matt but just remember one thing, in a built up area like you are in at the moment then sadly you will not create a noise free zone.

    You can reduce it as much as possible and this will vary from location to location.

    In most cases that i deal with then they always turn out to be of multiple sources.

    I still feel that you need to convince your neighbour to turn off his mains supply just, if nothing else, to eliminate him from the eqasion, just turning off each item one by one will not prove anything at all only confuse the situation.

    Carl is trying to help all he can but he or anyone else cannot produce the miracle we all hope for.

    Keep in touch.
    M6VWM likes this.
  17. M6VWM

    M6VWM Member

    Agreed Ken thanks.

    When it’s in the s5 region it’s very useable so if I can get it around more often there I’ll be over the moon.
  18. Ken G3SDW

    Ken G3SDW Moderator

    Talk to your neighbour as all too often it is close to home, as i said at least eliminate him or you will be just chasing your tail.
    M6VWM likes this.
  19. Ken G3SDW

    Ken G3SDW Moderator

    By the way Matt as you may well have noticed i had to delete 3 of your posts earlier as they were all the same.
  20. M6VWM

    M6VWM Member

    Apologies, I think it’s the internet at work I’ll try not to use it here again.

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