Wandering 144 MHz RFI

Discussion in 'EMC Matters' started by Mike German, Feb 20, 2019.

  1. Mike German

    Mike German New Member

    Hallo,
    My name is Mike German and I have just joined this group (although Ken may remember my Plasam TV!) I am not a licenced amateur. I am currently studying meteor reflections on 143.050 MHz and have found a source of RFI that wanders around from 142MHz to well above the 144MHz start of the amateur 2 metre band. It has a bandwidth of about 200kHz - see file) I first found this interference over a year ago and with portable gear and make-shift Yagi tracked it down to at or near a sewerage pumping station. The pumping station is some 400 metres from me and I have detected the signal from at least 1.3km.

    I contacted the pumping station operators last year and it was difficult to find technical staff who would talk to me (although they do appear to be concerned) but unfortunately by the time they made a site visit the RFI had gone (it lasted from January to May) At the time I was mainly monitoring noise in my narrow passband down at 143MHz. However, sinsce its return in January this year, I am monitoring more closely and have found it encroaches on the amateur 2 metre band. I am surprised by the complexity, bandwidth and agility of the signal.

    As a non-licenced radio amateur (non-transmitting of course:) I have no recourse to OFCOM. I do not know of any amateurs operating in near location of SK22 2HB who would be affected by it. I am therefore hoping for some advice or possible recognition of the offending signal.

    Regards
    Mike 144 MHz  2019-02-20_122127.jpg
    Hayfield Derbyshire
  2. Ken G3SDW

    Ken G3SDW Moderator

    Hi Mike hope you are well, yes i remember you well.

    Well as you say you cannot get any help from Ofcom so your only choice sadly is to go back to whoever you contacted the last time, if you conclusively proved it then they still would have to get involved so that the only route you can take.
  3. Mike German

    Mike German New Member

    Hallo Ken,
    I am glad to see that you are keeping busy on this forum and hope you are keep well too. I guess I realise I am on my own on this one but hoping there may be an local licenced amateur who could be affected or someone might recognise the source. Re: the pump station operators, I am back in contact again but all the staff previously involved have moved.
  4. Ken G3SDW

    Ken G3SDW Moderator

    Just keep at it and as long as you are completely sure it is coming from them then i am sure they will get it sorted..

    As for busy then yes i also look after the RSGB EMC Help Desk as well so between the two of them i can keep out of mischief lol

    Keeping fairly well myself but the other half is not so good but we are getting there all be it slowly.
    Last edited: Feb 20, 2019

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