Toobuilder

Toobuilder

Well Known Member
Finally have my EDC-10A remote compass installed and wired. After calibration on the compass rose last night, the display warned that the calibration was extremely unreliable (or something to that effect). Did it one more time with the same result. The cal was done with the engine running, lights on, etc. The unit itself is mounted on the top of the HS, under the fairing using aluminum pop rivets. Aside from the stab trim wiring and the LED tail light bulb on the rudder, there is no electrical power running back near the unit. It should be a "clean" magnetic location so I'm baffled at the poor calibration.

So this leads to my question- the cable I used to connect this unit to the D10A was left over from my rudder trim (now removed) It is NOT shielded nor twisted. I've heard that Dynon is backing away from the requirement for shielded data bus cables - is this an issue for me, or not? I can order and install the Dynon supplied EDC-10A cable, but I'd rather not if it's not a real issue.

Any ideas?

Thanks.
 
Shielding the wire is for external interference to the digital signal, it's not to keep magnetic interference away from the magnetometer. So this is not your issue.

The first thing to try is always to take a standard magnetic compass and put it on top of the remote compass. Compare the reading in that location to one taken standing outside the plane. If they are much different, you have an issue in that location.
 
You don't mention any mounting hardware to align the remote compass with the display... The install manual was clear that the horizontal plane the EDC-10A is mounted on needs to be aligned very precisely relative to the head unit. On the -6, the instrument panel is tilted significantly relative to the longerons, something like 10 degrees if I recall. I don't know what the effect of *not* aligning these is, but maybe this is a factor?
 
Try using a portable compass and survey the area around the magnetometer. I found that the rudder cables were somewhat magnetized and the compass needle would swing quite strongly when near them, though it did not seem to affect the magnetometer.

My magnetometer is installed in the same location as yours, but I do not have any problems with calibration. I used an aluminum tray attached with nylon bolts for adjusting the angles of the magnetometer. Check your attachments for magnetism by running your portable compass around them.
 
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Yes, the magnetic survey sounds like the thing to do. I get pretty wild swings of the compass in flight and that results in a wild ride when the heading bug is driving the autopilot.
 
F1R,

1) Pin #12 is not 12V. There is no 12V out from any D10A pin. The voltage here is 16.8V, and is internally fused at 50ma.

2) Nope.
 
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