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Anyone replace their compass with a SIRS compass?


Geoff

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+1 for the Sirs. My whiskey compass would not stop vibrating and I had the prop dynamically balanced to less than 0.02. Clarence's guys told me the verical card just would not swing properly during an annual so I asked him to put in a Sirs compass. Same installation as Big Tex.

Works great.

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I have a vertical card compass on my M20J and I am very happy with it. Specially when in turbulence, much easier to read than a wet compass. I think the magnetization issue is more related to pre M20J models. If you use electric arc welding on the compass structure the structure will be magnetized. However if you use torch welding you do not have the magnetization problem. 

 

The vertical card compass is probably more sensitive to structure magnetization because it uses stronger magnets than wet compass. A big magnet will pull to the closest magnetic structure (force interaction) while a tiny wrist magnet will pull to the North (field orientation).

 

José

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The PAI-700 vertical card compasses generally work well for a short time. Then they stick. Not worth installing one if you don't want a whiskey compass.

 

The SIRS is the best compass on the market at this time. Tens of thousands of fleet hours on them with no problems.

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The PAI-700 vertical card compasses generally work well for a short time. Then they stick. Not worth installing one if you don't want a whiskey compass.

 

The SIRS is the best compass on the market at this time. Tens of thousands of fleet hours on them with no problems.

 

Maybe the SIRS is not good enough for helicopters. Since all the Robinson helicopters are equipped with vertical card compass from the factory. And there is more shaking in a Robinson than in a Mooney.

 

José

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Geoff, I did not experience any issues with high compass deviations.  Also, If I remember correctly, the fluid in the compass is a silicone fluid and "thicker" than a regular alcohol wet compass, therefore any swings in direcrion are damped much better.  When I installed it, I swung the compass on the compass rose whcih fortunately was on the field to complete the deviation card.  I mounted the compass in its original location.  Like I said, an excellent product, but others seem to have good success with a vertical card as well. 

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