Radio interference when using other 12v devices

Discussion in 'Tech/Mech General' started by Mattyjwr, Mar 29, 2014.

  1. Mattyjwr

    Mattyjwr Funster Life Member

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    Greetings.

    I seem to be having interference problems with our FM radios whenever I plug in my 12v charger for my dash cam. I have the same issue when I use my wireless reversing camera - I had thought that it was the wireless signal but I think that the interference only occurs when I have the monitor plugged into the ciggy socket.

    The interference reduces the signal strength of the radio and causes it to do frequent scans to look for a stronger signal.

    Any suggestions on how we can deal with it?

    I've thought of running a power supply from the LB to the front of the van so I can power the SAT NAV & reversing camera monitor in case the interference is linked to being on the same power supply as the radio but 1) I would rather not have an extra wire running through the van unless it is essential & 2) I fear that the problem is based on interference with the radio waves so that the circuit is irrelevant.
     
  2. pete4x4

    pete4x4 Read Only Funster

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    Nothing you can do apart from buy a better quality 12v adaptor.
    Try getting a known brand of 12v usb charger which is CE marked. It's a bit of a minefield but the more you pay the better the screening of the radio frequencies that these power supplies generate. Belkin seemed to work for me
     
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  3. Mattyjwr

    Mattyjwr Funster Life Member

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    If I wrap the chargers & cables in tin foil, will that help until I can get better chargers?
     
  4. pete4x4

    pete4x4 Read Only Funster

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    Might do, depends upon whether it's conducted or radiated, Ive never actually tested my bad ones yet, the tin foil needs to be earthed though.
     
  5. Yorick

    Yorick Funster

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    I have same problem in my Audi.

    If I use rear demister, radio goes shit.
     
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  6. ivorantony

    ivorantony Funster

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    A twisted pair running from the leisure battery through a choke will reduce a lot of interference, but your protagonist the camera/ 12 volt to 5 volt charger should be looked at first, try and keep the wiring apart and also try to run your aerial lead separately from all existing wiring,
    I have just changed my rear camera to a twin wired one, it gives me a better picture without getting a bleed in picture from other sources, at the time I had presumed it was the main culprit for my poor radio reception,
    But the main problems will be quality of radio and aerial, good quality doesn't come cheap, :thumb:
     
  7. karl c

    karl c Funster

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    some chargers have pore EMC on them. They give of RF witch will mess your radio up.
    CE mark dose not mean any thing as they get the CE on the first paten then cut back on the parts.
    you could try a ferrite ring around the cables.

    http://www.cfe.com.tw/menu-ferrite-cores.htm
     
  8. pappajohn

    pappajohn Funster Life Member

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    could be a poor earth on the radio aerial or the radio itself.
    Will still work ok but wont be fully shielded against spurious RF interferance
     
  9. aba

    aba

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    Thats probably where the aerial is.......2 vertical lines built into the rear window element
    Again could be a bad earth on the heater elements causing it to earth through the radio.
     
    Last edited: Mar 29, 2014
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