Possible interference to compass by pilotAware

[SWP22C]

We are running a Classic PilotAware installed on a group owned PA-22. It is situated on the far right of the coaming and powered by the recommended Anker power pack.
All works fine - and has, without doubt, forewarned us of a potential conflict several times since installation in February - but we have begun to notice our standard compass wandering (situated directly in front of the P1 position, on the left, on top of the coaming.
The aircraft had its annual, which included a compass swing, in March 18.
Has anyone suspected that PilotAware has influenced their compass. PAW maybe completely innocent and it is an old aeroplane, but I would be interested to hear of any issue and, maybe, solutions.
We could install it on the back shelf, which will be very effective on a fabric covered aeroplane, on catching someone sneaking up behind us, but that would be much less useful, I would think for head on conflicts.
Many thanks, in advance, for any comments.

[Ancien]

Have you taken the magnet out of the 1090 antenna?
My PAW is hidden just below the compass and has had no issues at all.

[SWP22C]

Aagh! We have a plastic top to our coaming and both the box and the aerial are held in place by Velcro. I didn't look to see if there was a magnet in the base.

Very probably the culprit. Pretty basic stuff!

Many thanks, Ancien.

[SWP22C]

Some feedback for anyone's interest.

Yesterday, I removed the small magnet from inside the base of the aerial.
It is very small indeed but, moving it around above the coaming, gave me anything up to a 45 degree variation in compass heading.
Following that, one of my other group members did a navigation detail with a student, i.e. no reliance on Skydemon etc, and they found no compass issues.
So, that seems to be that.

[Admin]

Hi All,

Yes this was reported a few times, of course with Rosetta, both antenna are screw mounted, so no magnets involved !
The one other thing to be aware of, if using a remote GPS mouse, I think they also have a small magnet in the base

Thx
Lee

[JCurtis]

This has come up a few times, so I'll repeat what I said on a previous post here too...
With Rosetta being very portable, anyone moving one between aircraft should check for compass issues every time.

Same goes for power supplies, battery pack supplies, phones, and tablets - they all can impact the compass.  I've seen a battery pack power supply on top of the coaming impact a compass at 20cm.

People also need to be wary where an electronic compass unit is mounted behind a panel for those with digital instruments, then they also put some other electronics nearby and don't check.

Always fun to pick up paperclips with a phone or tablet to see where they hide them, for either case detection or where the gizmo that makes it vibrate is inside.