HF interference on my ring main?

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

  1. Ken G3SDW

    Ken G3SDW Moderator

    Matt i posted my last post just before i turned in last night and one thing kept going throng my mind and that is what you said, ie This suggests its either the mains itself, or the PSU (Diamond switching).

    When you turn off your mains supply then surly you use battery power to supply your rig?

    SMPS`s do sometimes cause RFI but if the mains is totally off how can they.

    Can you explain why you mentioned this.

    If the RFI is coming up the mains supply then taking out the antenna then it will still be there, if when the antenna is back in nad the RFI returns then it is being picked up by the antenna.

    You mentioned early this year that you were having your mains supply checked out by a family member, is he a qualified electrician,
    NICEIC Approved or someone who is doing you a favour.

    He should be able to check to see if there is something still connected to your mains supply when everything else seems to be disconnected.

    I will say again a ring main with nothing connected to it cannot to cause RFI, other than if any new electronic meter has been supplied in recent times, which is a very long shot.
    M6VWM likes this.
  2. Ken G3SDW

    Ken G3SDW Moderator

    Matt been doing some investigation and i need to know what sort of electricity meter you have, as you say the house was built in 86 so assume that after 30 years plus that it has been replaced, no doubt before you moved there, this is a very long shot.
    M6VWM likes this.
  3. Ken G3SDW

    Ken G3SDW Moderator

    Matt tell me more about your Hive system??
  4. M6VWM

    M6VWM New Member

    Hi Ken,

    Yes my brother is a fully qualified electrician I am waiting for him to come back to change my fuse board for a RCD and do a full diagnostic. He found a bad earth in a couple of sockets which were replaced and resolved that, I had a few surge protectors blow but that is now sorted. I also had a decorator in and I checked the light switches he had removed whilst decorating and found those incorrectly wired up and corrected that too. My brother feels there is still something not quite right with the earth and he has said he will do a thorough test when he visits. Still waiting sadly.

    I did wonder about the hive system, I have tried isolating the boiler power at supply and unplugging all the powered devices, noise is there. This would leave the door sensors (battery powered) and thermostat (also battery), removing batteries didnt seem to make a difference. Girlfriend also recently turned on a water pump in the garden, turned that off too.

    The electricity meter is the original one it has never been changed and I must admit I hadn't even considered that. Let me go check what model it is.

    I have also put up new antenna at the end of the garden and I know the neighbour behind my house on another street tends to have compressors, extractors and all sorts of things in his garage for his classic cars and spray booth. I don't suspect him however as the weird background noise on the 2m band is for an antenna thats close to my house not his.
  5. M6VWM

    M6VWM New Member

    I also did a thorough search of the attic for a tv amplifier or similar but couldnt find anything. Also isolated shower power supply and disconnected my bathroom shaver point. TUrned off fridge and all appliances too again no difference. It's very odd.
  6. Ken G3SDW

    Ken G3SDW Moderator

    Hi Matt, the simple fact is that with your mains off then the problem is not there, that can only mean it is being generated by something in your own home, there is no other way.
    Bad connections will not give you noise problem, well steady ones as arching will be more like a crackle.

    Let us know what your brother finds when he changes your electrical system, and if you could take a picture of your meter, with details, as we at the EMCC are discussing all possibilities of what it could and what can be done.
  7. M6VWM

    M6VWM New Member

    Here is the meter, the white box seems to suggest 2003, I lived here from 2001 but I don't recall them changing it.

    Attached Files:

  8. Ken G3SDW

    Ken G3SDW Moderator

    Thanks mate i will pass it on the the EMCC
  9. M6VWM

    M6VWM New Member

    Well some more info today and sadly can now confirm the noise is not just from inside my house. Running on battery today with no power to entire house still seeing s7 so it seems interference is external. Turning off the fuse box makes no difference it used to drop it to 3 or 4 but now stays at s7. Perhaps it was a fluke before or this is just hiding any change in local RF

    I am now suspecting the garage near to my pole which is a chap who lives on the road behind. He uses his garage as a spray booth so you sometimes hear compressors and fans going could it be that?. He has always been a bit rude sadly when I tried to say hello in the past, so I’m not hopeful of him being willing to test with me.

    Such is life never mind. Thanks for all your help and time. I think I’ll wait until my fuse box is changed and have another look after. I may just have to accept my house isn’t in an area conduscive to radio.
  10. Ken G3SDW

    Ken G3SDW Moderator

    The situation you have now is becoming most common, multiple sources of RFI

    The guy in his shed at the rear is not the main one but just another one, your main concern is what ever is causing the big problem in your house.

    Hopefully that will be rectified once your house wiring and new consumer unit is fitted.

    The assuming that it is still there then you can concentrate on the other one, in the mean time i will close the case and open a new one assuming that you still have problems in the future.

    Good luck mate.

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