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Major RFI on 40-20 Meter Bands

Discussion in 'Ham Radio Discussions' started by K5RWD, Aug 1, 2020 at 12:26 PM.

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  1. K5RWD

    K5RWD Ham Member QRZ Page

    I have been struggling with an RFI issue(s) (well more than one) lately, but particularly one that has forced me off of the 40-20 meter bands indefinitely. This start just a couple of months ago, and it's on there 24/7 now and has shut me down. My question, is there anything I can legally do about it if I can find the source?

    I'm attaching a link to a sample video of my problem noise below.


  2. N0TZU

    N0TZU Platinum Subscriber Platinum Subscriber QRZ Page

    That's pretty bad.

    The question of what to do about it is very dependent upon what the source is and where it is. No sense in worrying about that now until it's located.

    Is it present 24/7 or is there a pattern to it? Is it present on any other bands, or on the AM broadcast band? Did something change in your house or the neighborhood recently?

    First thing is to run your radio from battery and shut down AC power to your own house to verify it's not coming from something there. A portable shortwave radio is very useful for this, or a regular AM radio if the noise can be heard on the AM broadcast band. Don't forget to remove backup batteries from any devices in the home that have them during the test.

    Assuming it's from elsewhere, then walk around the neighborhood with the portable radio to see if the signal strength will tell you the direction it's coming from.
    K5RWD, W9RAC, W4IOA and 2 others like this.
  3. W9RAC

    W9RAC Platinum Subscriber Platinum Subscriber QRZ Page

    DO THIS FIRST. 73 Rich
  4. W9RAC

    W9RAC Platinum Subscriber Platinum Subscriber QRZ Page

    That is a tuff one for sure. Should be pretty EZ to locate if inside, and maybe if not. You may have to use a AM radio as a "sniffer" to find the source outside if ends up not being your QTH. I hope its inside your QTH for an EZ remedy for you. 73 Rich
  5. K5RWD

    K5RWD Ham Member QRZ Page

    Nothing has really changed in the house, I didn't have this problem a couple of months ago. I will try turning off all house power and see if it still persists. I have an HF in the mobile, I didn't think about it until now but I can go out there and see if it's in the mobile to. All my HF radios in the house pick it up, so it's not my rig.

  6. W6MK

    W6MK Ham Member QRZ Page

    Neighbors get new electronic gizmos or electric appliances all the time. The neighborhood QRN can
    really change drastically over time.

    Powerline-generated interference also can be seasonal. Summer began a couple of months ago, as I recall.
  7. NE3Z

    NE3Z Premium Subscriber QRZ Page

    Is there a hospital near you?
  8. N0TZU

    N0TZU Platinum Subscriber Platinum Subscriber QRZ Page

    Hams and their families get new gizmos too, and then forget about them.
  9. KO4LZ

    KO4LZ XML Subscriber QRZ Page

    The noise has a period of almost exactly 1 second, depending on how you measure it.

    Frequency-domain analysis doesn't show strong spectral content at 60 or 120 Hz, so probably not power line noise (which also normally wouldn't have the above-mentioned time-domain periodicity)
  10. NE3Z

    NE3Z Premium Subscriber QRZ Page

    I listened to powerline noise for five straight years, it’s not powerline noise. You guessed right.
    KO4LZ likes this.

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