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Alternator whine

Discussion in 'Mobile Radio Systems' started by KI7NNK, Jan 11, 2022.

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  1. KI7NNK

    KI7NNK Ham Member QRZ Page

    I did that and the wine was still present. The Yaesu black wire goes back to my negative buss bar on my auxilary panel (eventually to body ground near the battery ground.)
  2. KI7NNK

    KI7NNK Ham Member QRZ Page

    This is the kind of thing I was hoping to find at the outset of this post. Thanks. Hoping it will be sorted by re-routing the ground back to the bus, but we'll see. It just may be happenstance that the impedance through the negative busbar is just closely matched to the impedance of the body. Who knows, lets hope.
  3. KB0MNM

    KB0MNM Ham Member QRZ Page

    Post #10 talks about ground loops. Post #9 reveals a painted antenna mount.
    Courtesy KF5LJW's list, a bit of reading:
    ( Put that one in your browser- should produce a lengthy PDF )
    ARRL Grounding and Bonding for Amateur Radio ( Second edition seems to be out )
    ( Methods, might not buy much for your situation ). 73
  4. WA7ARK

    WA7ARK Ham Member QRZ Page

    Ok, this is confusing because there is a lot going on.

    During the last test when you still had the whine (coax from diplexor to Yaesu disconnected), was the GMRS black wire disconnected or connected?

    You are absolutely sure that the diplexor itself is isolated from the car body? You would have to disconnect all three coaxes to find out.
  5. K6CPO

    K6CPO Ham Member QRZ Page

    It seems like everyone is going through a lot of work to resolve this problem..

    When I first installed a mobile radio in my truck ten years ago, I had some audible alternator whine ( although not enough to affect operations.) All I did was throw one of these into the power leads and the problem went away. Four different radios later and I still don't have any issues.
    AK5B and WD5GWY like this.
  6. K0UO

    K0UO Platinum Subscriber Platinum Subscriber QRZ Page

  7. N1IPU

    N1IPU Ham Member QRZ Page

    Is the whine at idle or through the who range of rpm? I haven't had that problem in a long time because I upsize the alternator and harness as part of the install. When I do encounter whine first thing I do is go through the charging system and look for weak links. One bad connection can cause that. When troubleshooting power issues you start at the beginning, not the end. Most tend to look at the last link of the chain which more often than not is a waste of time.
    KB0MNM and AK5B like this.
  8. KB0MNM

    KB0MNM Ham Member QRZ Page

    I like certain parts of each of the last three posts-
    in order- I might go with a different maker, eg. Kenwood ( JVC ) (MFR./TM/R/C.)
    I might look twice at the K0BG website, because he considers them 'band-aids' for other problems. They do work.
    "Who range of rpm"? Whole range of RPM- revolutions per minute. Dr.Geissel(sp?)/Dr.Seuss or Dr.Who ( it's a british sci-fi thing ). Some vehicles already have oversized alternators, others- not so much. Batteries wear down, too!
    K0UO likes this.
  9. N1IPU

    N1IPU Ham Member QRZ Page

    What creates whine is ripple usually caused by poor connections or corrosion in the leads or connections. Losing a diode or poor regulation is another. Sometimes a bad cell on a battery. RPM and noise increase under load are good indicators.
    It's the first place I start when I have such issues. Going with a larger output alternator and upsizing the harness is good insurance at keeping issue at bay but regular maintenance is another. I have gotten whine from corrosion in the positive lead and or ground most often though. Some regulators are just noisy too but I thought most manufactures had that under control by now.
    KB0MNM likes this.
  10. WA7ARK

    WA7ARK Ham Member QRZ Page

    There does not have to be anything abnormal with the basic wiring or alternator charging system in a car to have Alternator Whine in ham radios. With a new install, if you get alternator whine, the problem is a "ground loop", period.

    Some ham rigs are more prone to the effect of a ground loop than others, the installation being the same. It has to do with the design of the radio itself.

    If you have an installation that suddenly develops alternator whine after not having any for years, that is the time to look at the car's charging system. Sudden onset of alternator whine could mean a partial failure in the rectifier stack inside the alternator, or a problem in the under-hood wiring related to the charging system.
    WD5GWY likes this.

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