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Condenser Mic Picking Up neighbors CB/Ham Radio

  1. I have a rude and vulgar neighbor one house over (Within 50ish feet) that has a large CB(I'm assuming CB) radio antenna and my new Condenser mic keeps picking up his transmissions. It's makes my podcast and twitch content creation extremely annoying. I've bought ferrite cores ( https://www.amazon.com/gp/product/B009ENG6TI/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1 ) and an extension cord for the 3.5 plug in. It's not a high end mic ( https://www.amazon.com/gp/product/B00K68MT9Q/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1 ) so there's no large cables or phantom power. I put the cores on 5 different points of the cable and the extension but nothing I do gets rid of his signal or even lessens it's strength. Do I need a better mic? I just need to know what to do to fix this. I've researched for hours and found nothing that could help and I'm at my wits end.
     
  2. mike1959

    mike1959 TS Evangelist Posts: 1,026   +51

    Hi, Issues like this can always be sorted out, once you find out where the RF is getting into your pc.
    Ttransmitted RF gets into another system through long wiring, so the worst case for this would be where some areas have the telephone wires 10 metres up in the air on poles, in the street, which then go to each house, that would be where the signals would get into the phone system. Some ferrite chokes just before the wireless router should help there if using an ethernet cable to the pc.
    Otherwise it's the mains wiring around the house that will pick up the 27MHz siganls, and then ferrite chokes on the pc's mains lead should help.
    Are you using a wireless router? Is the pc powered by mains, or is it a laptop where it could run off the battery, if yes does the problem still happen when run only on battery?
    Also at risk are speaker wires plugged into the pc, monitors not usually a problem as the leads do have chokes on them.
     
  3. ffawesomesauce

    ffawesomesauce TS Rookie Topic Starter

    PC(Gaming rig) connected via wifi, and it's effecting my microphone plugged into the mic in on my onboard soundcard.
     
  4. mike1959

    mike1959 TS Evangelist Posts: 1,026   +51

    Hi, It's most likely the RF interference is getting in to your PC's electronics through the mains supply.
    (Of course the real 'fix' is for your CB/Ham neighbour to turn down the TX power, I know that 1KW is not unusual.)
    But there is a lot you can do fix this problem, mostly heavy filtering of you mains supply to your PC, plus even some sheilding using foil if needed.
    There are also mains smoothing adapters, ( not the surge blockers) which would add an extra level of protection.
    If you can use several 'clip-on' ferrite chokes on your PC's mains lead. that would block common mode currents.
    I know my PC mains leads don't have any filtering, the mains transformer in the PC will have some filtering.
    I would suggest a clip-on ferrite choke near the wall plug, and another near to the back of the PC, as a start.
    I have this 3 way mains filter for my PC, (photo.) mains_filter.JPG
     
  5. jobeard

    jobeard TS Ambassador Posts: 9,322   +622

    Mic in is acting as rf detector. Look up 'low pass' filters. The choke goes inline with the mike & the cap goes from mike to ground
     
  6. mike1959

    mike1959 TS Evangelist Posts: 1,026   +51

    Yes 'jobeard ' has a good point, it's totally possibe to be that. It will mean taking the mic apart and soldering in 2 components, one inductor and one capacitor to form a low pass filter, I'm surprised it's not fitted as part of the design, as it's not expensive to do. In fact just one 0.1 uF from the mic signal inner, to ground might be enough.
     

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