New magnetic compass

Discussion in 'Avionics and Upgrades' started by Jdm, Feb 24, 2020.

  1. Jdm

    Jdm Pre-takeoff checklist

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    Any recommendations for a new C172 magnetic compass? We’ve had this ratty one forever. I’ve rebuilt and serviced it a couple of times over the past 20 years. Figured we’d have a new one installed while it’s in for avionics upgrade. The shop is planning to go with a vertical card type but I’ve not read great reviews with those. Thanks.
     
  2. schmookeeg

    schmookeeg Administrator Management Council Member

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  3. Jdm

    Jdm Pre-takeoff checklist

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    Thanks! I have read about that one. It seems to be well liked.
    It’s not that I dislike like a vertical card. I just want a solid functioning magnetic compass and have read a number of negative reviews about vertical card types mounted on the glareshield
     
  4. James331

    James331 Ejection Handle Pulled

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    I have a vertical, work planes have vertical, not that I ever use the thing.
     
  5. schmookeeg

    schmookeeg Administrator Management Council Member

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    Yeah, I've heard weird stories about vertical cards "chattering" and not moving smoothly, making them mostly unusable. I think they need to be mounted loosely to the glareshield to work properly, and people torque em down. Been awhile since I thought about it, I may be misremembering that detail.

    I think anything is 10x better than a whiskey compass, so you can't really lose either way. :D
     
  6. Jdm

    Jdm Pre-takeoff checklist

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    Yes, anything is better, but figured I should check since we only get a new one about every 30 years or so!
     
  7. NordicDave

    NordicDave Pattern Altitude PoA Supporter

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    I installed a vertical card compass with A&P supervision and log entry. My local avionics shop calibrated the new compass and used a professional magnetometer to print a nice compass deviation card. Cost was a $120 for 2 guys performing the work.

    No way anyone can DIY every 30 degrees on a compass rose by precisely lining up spinner to tail on a painted line. Though we will see the next 3 posts of guys who say they can differentiate 1 or 2 degrees of precise deviation without a magnetometer.
     
  8. Jdm

    Jdm Pre-takeoff checklist

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    I think you got yourself a bargain! How well does it work for you? Glare shield mounted? I actually used to put them in back when I was a kid. Got my A&P right out of high school. We had a handheld device to check them. One guy would stand on the ramp holding this master compass contraption while the other would taxi around in circles stopping every 30 degrees at the command of the ground guy. The good ole days:)