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Thread: Radio issues when low RPM

  1. #1
    sbmackie's Avatar
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    Default Radio issues when low RPM

    Have a generator. Is there any kind of gizmo that I can add to the line somewhere to keep the voltage up for better radio transmissions when RPM is below 1000 RPM? Below 1000 RPM, it's garbled, fuzzy, sometimes unreadable (transmissions; reception of course is fine); above 1000 RPM, all is well.

    Thanks

  2. #2
    Gilbert Pierce's Avatar
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    Default Re: Radio issues when low RPM

    I had the same problem. Taxiing at MEM I had to ride the brakes, keep the RPM up so I could hear ground.
    I solved the problem, installed an alternator.
    What is your voltage at idle?
    Make sure everything is turned off except the radio.
    You could set the voltage regulator higher maybe, they are adjustable.

  3. #3
    Old3pacer's Avatar
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    Default Re: Radio issues when low RPM

    Until you replace your generator with an alternator
    you can use a handheld prior to takeoff

  4. #4
    sbmackie's Avatar
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    Default Re: Radio issues when low RPM

    Hey, a new use for the 31 year old KX-99!

  5. #5
    sbmackie's Avatar
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    Default Re: Radio issues when low RPM

    Pray, how does one set the voltage on said regulator? Need…more…volts.

  6. #6
    sbmackie's Avatar
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    Default Re: Radio issues when low RPM

    Quote Originally Posted by Gilbert Pierce View Post
    I had the same problem. Taxiing at MEM I had to ride the brakes, keep the RPM up so I could hear ground.
    I solved the problem, installed an alternator.
    What is your voltage at idle?
    Make sure everything is turned off except the radio.
    You could set the voltage regulator higher maybe, they are adjustable.
    Which alternator did you get?

  7. #7
    Gilbert Pierce's Avatar
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    Default Re: Radio issues when low RPM

    Quote Originally Posted by sbmackie View Post
    Pray, how does one set the voltage on said regulator? Need…more…volts.
    See page 7 or take it to a generator repair shop. There are some still around.

    I installed a Interav alternator 20 some years ago. NO longer available. Search alternator on this site. There is a lot info about installing them. B&C is one that is STC'd https://bandc.com/
    Attached Files Attached Files

  8. #8
    Old3pacer's Avatar
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    Default Re: Radio issues when low RPM

    B&C makes a good product and offers good support

  9. #9

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    Default Re: Radio issues when low RPM

    I have an original 20A generator and it works well. Not great, but adequate. If this is a daytime problem, I would first question your battery. Use a load tester. If your battery is good, you may need to rebuild your generator. If your battery and generator are both good you shouldn't have a problem. If it's only a night time problem, I changed every light bulb to LED's, particularly the landing and taxi lights to decrease my total load. It really made a difference at night. My problem was never my radio transmission power, but my lights would dim near idle. I've fixed that with LED's.

  10. #10
    sbmackie's Avatar
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    Default Re: Radio issues when low RPM

    Quote Originally Posted by Subsonic View Post
    I have an original 20A generator and it works well. Not great, but adequate. If this is a daytime problem, I would first question your battery. Use a load tester. If your battery is good, you may need to rebuild your generator. If your battery and generator are both good you shouldn't have a problem. If it's only a night time problem, I changed every light bulb to LED's, particularly the landing and taxi lights to decrease my total load. It really made a difference at night. My problem was never my radio transmission power, but my lights would dim near idle. I've fixed that with LED's.
    Test battery load like a car? Attach load meter, make sure it's above 12.6 or so, crank, see if it drops below during crank, run at idle, check voltage again for north of 14 to confirm generator is doing it's thing? What kind of voltage should a good generator be producing at idle?

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