radio and depth finder

Discussion in 'OnBoard Electronics & Controls' started by FreedomWon, Jan 24, 2015.

  1. FreedomWon
    Joined: Jan 2015
    Posts: 1
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    Location: Florida

    FreedomWon New Member

    I notice that when I key up my radio my sonar will show bold solid vertical lines on it. When I let go of the mic it stops. What is causing this?
  2. whitepointer23

    whitepointer23 Previous Member

    Your radio wiring and antenna lead might be to close to the transducer lead.
  3. gonzo
    Joined: Aug 2002
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    Location: Milwaukee, WI

    gonzo Senior Member

    It is caused by radio interference. There may be a bad shield somewhere. For example, a damaged coax wire or a faulty ground.

  4. CDK
    Joined: Aug 2007
    Posts: 3,324
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    Location: Adriatic sea

    CDK retired engineer

    Your radio shouts with 25 Watts RF power while your depth finder listens to milliwatts reflected from the seabed. Both signals are conveyed by coaxial cables that shield the signals from the outside world.
    They can only do that when the coax shield is properly grounded. My guess is that the antenna cable makes no contact with the plug or the radio itself has a poor ground lead.
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