Tuesday, May 12, 2020

RFI mystery


RFI issue spread across the band
Over the last let's say a month or so I have been seeing some RFI on the waterfall of my Icom 7610 that is new. For about 7 months I have been RFI free at my new QTH and was very happy regarding this fact. At my old QTH in downtown Toronto RFI was the norm. 20m seems to be the worst for the issue and it's not all the time and as for what are the times I am not exactly sure. I have been very lazy with trying to narrow down a time frame for the RFI events. Way back about 10 years I did have a plasma TV that gave me a huge headache but I was able to solve that issue with the MFJ 1026 noise cancelling unit. In my wisdom, I ended up selling the MFJ unit for whatever reason. To try to narrow down the issue I have done the following:
- Switched to my active antenna and I still had the issue.
- I change to battery power only and I still had the issue.
- I turned off the main AC circuit breaker to the house and I still had the issue while using battery power obviously. Oh and an added note.....my dear wife was not happy about that.
Sometimes the RFI stops but then soon starts 

-Switched to my dummy load and the issue was gone but so were all signals.
So from the above, it seems it is being picked up by the antenna and not something within my home. At this point, I have not tried to pinpoint times as to when or if the RFI is present. I will be within the next few weeks paying very close attention to times when I am on and if the RFI is present or not. Until then I wanted to see if I was able to solve the issue with the Icom 7610's filtering. The choices I have are the noise reduction option or the noise blanker option. As a side note, my previous rig was the Elecraft K3 and it had amazing filtering for RFI issues. It was time to put the Icom 7610 to the test and see how it performed. I tried both the NR and NB and found it was the NB (noise blanker) that did the trick. I was able to totally remove the RFI and still hear the CW signal that was getting buried in the noise. Within the noise blanker settings, you can adjust the level, depth and width. I did find certain settings worked better than others at removing the offending RFI. I did change over to my Elecraft KX3 just to see how it dealt with the RFI and I was shocked how it really was not able to remove the RFI and the Icom 7610 won hands down!
I have included some screenshots of the RFI in the post here and if anyone has any ideas of what it may be or other tests I can do please post a comment. One theory I have is our very close neighbour has what is called down it this way a "split mini". Until I moved to the East coast I had never heard of one or even seen one but they are a heat pump so you have heat in the winter and cool in the summer. It's about 30 feet away from my Endfed antenna but this is just my humble opinion. The trick for me will be to check out the radio when his split mini-cycles off.
The split-mini 

9 comments:

  1. I know that split mini from our vacation in Denmark. The house had something just like that. If the RFI is coming from that I think it will be simple to solve it by adding some ferrite to the mains line. I'm glad you can filter it with the Icom. I got very good results with the Icom filters as well. 73, Bas

    ReplyDelete
    Replies
    1. Good evening Bas very nice to hear from you, unfortunately if the split mini is the issue and it's the home next to ours it's not going to be all that easy to put ferrite on their mains. The good news is that the Icom 7610 can remove the RFI.
      Have a good week.
      73,
      Mike
      VE9KK

      Delete
  2. Try using a portable medium wave radio tuned to a quiet frequency in the middle of the day. Walk around and see if you can hear similar sounding interference. If you can then you should be able to DF it with the internal ferrite rod antenna.

    ReplyDelete
    Replies
    1. Good evening John thanks for taking the time to leave a comment, I do have an AM radio that is hand cranked powered and I can give that a go on the weekend to see what results I get from it.
      Thanks for the info and have a great week John.
      73,
      Mike
      VE9KK

      Delete
  3. No rfi is better than the with the help of filter eliminated rfi so, John's solution is the best I think good luck 73

    ReplyDelete
    Replies
    1. Panagiotis thanks for taking the time to read the blog and leave a comment, I am going to get out and about and find the RFI BUT once I find it unfortunately here in Canada enforcement is next to none. I will know where it's coming from and if it happens to be me I can look after it. If it is a neighbour I am out of luck and thank goodness the 7610 filter look after it. If on the other hand it's the local utility I can contact them and see if they can do something about it.
      Have a great week and stay safe
      73,
      Mike
      VE9KK

      Delete
  4. Hi Mike, you seem very sure that you'll be out of luck if it's your neighbour causing the issue - is that because you don't get along with him/her??

    73, Tom, M7MCQ.

    ReplyDelete
    Replies
    1. Good morning Tom, well we are very new to the area here, and I am not sure (I could be wrong) he would be too thrilled with someone coming to his front door asking for his permission to add filters to his split mini. I am able to remove the RFI using the great filtering on the Icom and that's suits me just fine. In the past I have approached very friendly neighbours regarding very minor issues BUT after that point in time because they know I am a ham and am I transmitting.......I am then informed in a polite way that I could be causing an issue with any appliance that does not seem to do what and when they want it too. So I have found it better to just remove the RFI at my end with filtering if at all possible.
      Have a great week Tom and thanks for stopping by.
      73,
      Mike
      VE9KK

      Delete
  5. Yes I understand the point about not "declaring" that you are a HAM to your neighbours :-) My next door neighbour asked about my EFHW for the very first time yesterday and I just told him it's an aerial for listening to overseas radio stations :-D

    Ah well, at least you've managed to filter the noise out.

    73, Tom, M7MCQ

    ReplyDelete