Feedback/Noise emitted on 10M in shack…

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  • #1012
    KO6KO
    Participant

    All,

    I recently installed an EF-Quad in my yard in Northern CA. I have the matchbox end attached to the top of my chimney (19ft up) and the other end attached to a fiberglass pole about the same distance up in the air. My shack is in my garage. I have about 50ft of coax (RG-8X) that goes from my rig to the antenna. My question is, when I tune down to 10M and when I transmit, my PC speakers make a LOT of noise. Obviously this is RF coming back down the coax braid. How do I resolve this? Can I attach a wire to the ground side on the matchbox that will dangle down vertical (say a 1/4 wave of some freq?) so the RF is emitted from that and not the coax? Can I loop the coax? Not sure if anyone else has had this problem.

    Please help!

    73
    Mike
    KO6KO

    #1017
    QRPME
    Participant

    It may not be common mode current Mike. (current coming back down the coax)
    Is is an internal speaker or external speakers on your PC?
    If it is external it may be the speaker wire receiving the radiated signal from the antenna. Some clip on chokes (toroids) may cure the problem.
    If not then try about 6-8 six inch coils of coax 3 or four feet from the rig.

    73 for now,
    QRPME

    #1020
    KO6KO
    Participant

    Thanks for the feedback. I was using the same external speakers with another antenna config (buddipole) at the same distance away from my shack with no problems. I would like to keep the emission on the coax limited and keep as much RF outside of my house as I can. I wasn’t sure if I could add a wire to the “ground” terminal on the matchbox that would go down vertically from my roof and that would act as the counterpoise. Thoughts?

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