More magnetometer

Rob,
I've around 10 hours on my kit now and am still working through the bugs.
One of these bugs is a crosswind error, that is I'm getting an indication of crosswinds that is greater than I believe it to be.
I put it down to magnetometer alignment issues and decided to run the mag align check again and in doing this I notice in your video that when you say you have aligned the aircraft with North your display is actually showing 356°. I find this a little confusing, especially when I paid more attention during my latest attempts to align the magnetometer than I did when I first installed it.
The first couple of times I attempted the re-calibration today were unsuccessful and so I went and watched the video again.
Now, in the video you decribe pointing the aircraft at north according to your display (I'd been using my landing compass to determine north)and so I followed suit and the calibration was successful. However, when compared to my landing compass and indeed my panel mounted compass the AFS readings are some 10° off.
What's the deal here do you think?
I have searched here and found your link to the magnetometer alignment issues but the content there doesn't provide the answers I need.
Thanks in advance (pun intended).
Colin

The point to north step is only used as a verification check, if you are 10 degrees off you are getting interference from something.
Here are some things we have found in the past:

1. Magnetometer mounted near steel bolts, landing gear, seat belt cables…..
2. Magnetometer mounted in the tail near the steel bolts that hold the tail on.
3. Sliding (steel magnetic frame) canopy open during calibration and closed while flying.
4. Steel or stainless hardware used on the magnetometer, should be brass.

Thanks Rob, I'll look into it.
Can you confirm then that if all is well then the heading display of "000" will correspond with North on my mechanical compass (assuming that the compass is accurately swung)?

The Magnetometers are only accurate to around +/- 4 degrees; you should check it on N, E, S, W

I discovered rather an embarrassing blunder......

In the belly of my falco is a redundant mounting for an extra fuel tank. When I installed the magnetometer I mistook this redundant carrier for a rib which would of course have been perpendicular to the longerons. Not being a rib and being a fuel tank carrier meant that it was aligned with the skin which is about 10° from the perpendicular......:eek: