Noise on 40m (Video)

Discussion in 'Ham Radio Discussions' started by VA6ADB, May 11, 2019.

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  1. VA6ADB

    VA6ADB Ham Member QRZ Page

    i built an inverted V antenna yesterday with apex height at about 20ft from the ground. The swr is flat at 7.200. I have S7+ noise throughout the band and on 7.020 and 7.110 there is oscillating S9+ noise. This is with both NB & NR turned on. I have icom 7100 and 7300 and its same on both. Before this antenna I was using an inverted V for 20m with no issues. Can someone guide me how to locate or get rid of this noise.
     
  2. K6RUV

    K6RUV XML Subscriber QRZ Page

    Finding noise is one of the biggest aggravations a ham can have. It appears that the whole band is oscillating not just the noise. It seems very wide too. It could be that you have two separate issues maybe. Try turning everything off in your house at the breaker while running your rig on Battery and see what happens? If the noise goes away then you have narrowed it down some.
     
    KI4AX likes this.
  3. WE6C

    WE6C Ham Member QRZ Page

    I had some outdoor cameras that sounded exactly like that but on 20 meters for me. Re-routing and coiling up the camera coax helped. That did not get rid of it entirely but lowered the noise level.

    I also had some LED light bulbs that had a very similar noise on 40 meters.

    YMMV
     
  4. NK7Z

    NK7Z Premium Subscriber QRZ Page

    See:
    https://www.nk7z.net/sdr-rfi-survey-p1/

    Also my article in CQ this month covering how to help ID these sorts of issues.

    Do a home power off test first, put your radio on battery, then kill the power to your home... If the RFI goes away, you are lucky, just bring things up one circuit at a time, and destroy the offending item... If the RFI is not related to your home, start building a loop antenna for DF use.
     
  5. N1ART

    N1ART Ham Member QRZ Page

    I had a metal balloon stuck in an overhead power line outside my dwelling which caused this, you have an AC leak I think.PSEG removed the metal balloon and no more noise.Walk around with an HF receiver like a dj-11X Alinco or an old AM radio tuned to 530khz, until you find the buzzzzzzzzzzzzz.Call your power company.If you live near a power tower(Pylon) I don't think you will get rid of that easy....
    guy I know AC2oy lives by a power tower(Pylon) and gets lots of noise like that.
    Find the source, hold up a flourescent shop bulb in the air , it may even light up!
    Good luck with it sir.

    PS. Phillips LED bulbs dont make HF noise....only the junk ones do.
    I have all LED and no noise.
     

    Attached Files:

    Last edited: May 14, 2019
  6. KB9BVN

    KB9BVN Ham Member QRZ Page

    If you can, try getting it higher. 20 feet is very low.
     
  7. KF5RBR

    KF5RBR Ham Member QRZ Page

    Sounds just like the noise I hear on 40 meters everytime my dishwasher is running.
     
  8. W7UUU

    W7UUU QRZ Lifetime Member #133 Administrator Volunteer Moderator Platinum Subscriber Life Member QRZ Page

    So turn your dishwasher off and help the guy out :D:D

    Dave
    W7UUU
     
    KA9JLM, WS4JM, N5AL and 1 other person like this.
  9. N3AB

    N3AB Subscriber QRZ Page

    I once told my wife to shut off the dishwasher and do the dishes by hand as I was trying to operate 40 meters.

    The swelling above my eye went down about a week later. :eek:
     
  10. KA8NCR

    KA8NCR Ham Member QRZ Page

    If this were really a team effort, he'd go over and do the dishes before he wanted to get on the air.
     

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