Dynon Compass serious problem

prkaye · #1 09-03-2010, 08:45 AM

I'm having a seious problem with the magnetic heading indication on my Dynon D-180. I did the magnetic calibration 3 times today, and every time the dynon heading indicator has serious and inconstent erros. Like -20 degrees error for north, +15 degrees error for east... so non-constant errors that cannot be compensated for by the offset value.
I tried it both with engine and equipment on, and then with everything except the Dynon turned off. No joy.
I have double-checked the magnetic intensity and total field values.
Any ideas? Does itsound like I hava a bad remote compass unit?

DFlyer · #2 09-03-2010, 10:54 AM

Phil,

It does sound like that magnetometer is defective. Please contact our Tech Support at 425-402-0433 or support@dynonavionics.com

Thanks,
Robert
Dynon Marketing

pierre smith · #3 09-03-2010, 11:19 AM

...at your airport? Is that what you're using to determine the 4 cardinal points?

Best,

Flybuddy2 · #4 09-03-2010, 11:23 AM

First check to see if on the setup-DSAB page the compass is showing. Either way, take a shot hooking your computer up to the DB9 cable and see if you can't load the new 5.4 firmware on there that just came out two days ago. To check for function run something metal or magnetic in front of your remote compass and see if it swings at all so at least you can tell if it's communicating with the D180.

647jc · #5 09-03-2010, 04:22 PM

Where did you mount the magnetometer? Did you mount it with the same incline or slope as your panel, 8 degrees? Are there any ferrous materials near by that might be interfering? As Pierre mentioned, did you use an airport compass rose or just another compass when you tried to calibrate the Dynon?

carguy614 · #6 09-03-2010, 07:26 PM

If you have a slider canopy, and you mounted the compass module suspended in the tail cone, the canopy frame in the open position will throw the compass off big time.
What you need to do is calibrate the compass cardinal points with the canopy closed, as it would be in flight.
I experienced the exact same issue, and then I noticed how much the heading changed when I slid the canopy back. 25 degrees or so IIRC. After a calibration with the canopy closed, all was well.

HTH, Chris

prkaye · #7 09-06-2010, 07:03 AM

I did use an airport compass rose. The compass module is on the floor in the aft fuselage, a good distance aft of the baggage compartment. This places it quite far from the canopy. I will check the area with a compass.
One possibility is this: the data cable was too long, so to clean up the slack I created a loop with the extra cable and zip tied it close to the compass. I suppose it's possible that the current through the data cable is causing a magnetic field through that loop which is interfering. I would be surprised if the very low current in such a data cable would create a measurable magnetic current in a wide loop of only a few turns, but it's worth a try. I'll straighten this out (pull the extra wire back away from the compass and see if it helps).
I don't think the canopy is the ussue... it's quite far from the compass, and the readings were all messed up with the canopy in the same position (open) that it was during hte calibration procedure).