Compass checks after installation

[GrahamB]

Having ordered my "Classic" I thought I should give some consideration to where to place the antenna.

Has anyone done any compass checks after installation of the earlier versions to see if there is any deviation while the unit is transmitting? 

Any advice or suggestions as to best (internal) antenna locations on a PA28 would be most welcome.

[JCurtis]

Having ordered my "Classic" I thought I should give some consideration to where to place the antenna.

Has anyone done any compass checks after installation of the earlier versions to see if there is any deviation while the unit is transmitting? 

Any advice or suggestions as to best (internal) antenna locations on a PA28 would be most welcome.

This came up on another thread too, relating to the dongle GPS units.

There is a small magnet in the base of the ADSB (TV Dongle) antenna, while this isn't that strong in terms of holding it to anything it is easily strong enough to disrupt a compass.

As most aircraft are generally either composite or aluminium then these magnets won't stick anyway, but try them on a bit of steel or waft them near the compass to check.

[exfirepro]

Hi Graham,

Can't help with your PA28 I'm afraid as I fly a flexwing, but checking the compass very carefully when and after fitting anything containing magnets, or made from metal (particularly ferrous metal) or which might generate a magnetic field due to electrical or electronic effects when powered up is a definite necessity.

When I fitted my first GPS several years ago (a small Memory Map Road Angel unit) on top of my pod near the compass, all was OK until I connected external power to the unit, when I noticed a significant compass swing of about 20 degrees. Fortunately, I was able to move my compass from the top of the pod to further up the front strut away from all my electronics and have had no problems whatsoever with it since (including several months flying with various versions of PAW).

I appreciate that moving your compass may not be possible, so please all take careful note of compass bearing before and after positioning ANY electronic equipment in your aircraft and remember, the effect may only be visible when the unit is powered up.

You may of course not find a problem, but if you do and can't move your compass there are always other solutions, e.g. different types of antenna without magnetic fittings are available and I suspect will probably appear for sale in due course. Alternatively, the small magnets in the base of aerials (or as mentioned in another thread GPS mouse units) can often be carefully removed and replaced by for example sticky pads or Velcro.

Best regards

Peter

[Paul_Sengupta]

The antenna that comes with the DVB-T dongle also has a magnet in the base.

I have some steel clips on my dashboard and handily it adheres to them! 

I find the main PAW unit doesn't affect the compass much, but the battery pack I have does. I keep it away from the compass.

[Paul_Sengupta]

If you want to remove the magnet from the DVB-T antenna, you can peel back the sticky base and magnet should be a silvery coloured thing in the middle.

[gvpsj]

On a similar theme anybody any data or information about aerial location and strobe lights, either LED or the old type? My ideal aerial position is about 18 inches from a pair (top & bottom) old type strobes.

thanks

John

[exfirepro]

Hi John,

I have Aveo Powerburst strobes on my flexwing. Well away from PAW out on the winglets and have seen no effect on PAW. Worth a test though, certainly if you intended to fit a permanent aerial.

Regards

Peter