I am trying to install a Precision Vertical Card Compass in my LAK17at.

My first attempt was in the instrument panel. That didn't work due to too much magnetic interference from the various speakers "under the hood".

I then moved the installation to the top of the left side of the glare shield as far forward as possible. Again, there is too much interference - source unknown. Could be magnetic, could be metal.

My next attempt will be to move the compass again and add some shielding to try and mitigate the interference.

Any good ideas on how to achieve a successful installation?

Thanks in advance for your help!

Lou (I have also posted this to the LAK17 Yahoo Group.)

On Friday, August 14, 2015 at 8:52:17 PM UTC-4, MNLou wrote:
> I am trying to install a Precision Vertical Card Compass in my LAK17at.
>
> My first attempt was in the instrument panel. That didn't work due to too much magnetic interference from the various speakers "under the hood".
>
> I then moved the installation to the top of the left side of the glare shield as far forward as possible. Again, there is too much interference - source unknown. Could be magnetic, could be metal.
>
> My next attempt will be to move the compass again and add some shielding to try and mitigate the interference.
>
> Any good ideas on how to achieve a successful installation?
>
> Thanks in advance for your help!
>
> Lou (I have also posted this to the LAK17 Yahoo Group.)

Some puck GPSs (like early PowerFLARM and LX7007) had very powerful magnets presumably for connecting to metal; two screws per magnet once you bend the plastic backing back a bit and it's gone (two magnets per gps). My compass would only point at the GPSs. Now, it's magnetic north... plus or minus a bit. I'd check my GPSs were I you. Easy to fix (bit of velcro holds them well since they're light).

There's compass sensors in the Air Glide
sensor unit; so the Installation Manual
contains complete instructions on
required distances from magnetic
sources:

http://www.air-
avionics.com/air/index.php/en/customer
-support/air-glide/39-sensor-unit-
installation-manual/file

Here in Canada a magnetic direction
indicator can be used instead of a
compass in gliders. That may include a
flight computer moving map with a North
arrow.

So why install a compass?

On Friday, August 14, 2015 at 8:52:17 PM UTC-4, MNLou wrote:
> I am trying to install a Precision Vertical Card Compass in my LAK17at.
>
> My first attempt was in the instrument panel. That didn't work due to too much magnetic interference from the various speakers "under the hood".
>
> I then moved the installation to the top of the left side of the glare shield as far forward as possible. Again, there is too much interference - source unknown. Could be magnetic, could be metal.
>
> My next attempt will be to move the compass again and add some shielding to try and mitigate the interference.
>
> Any good ideas on how to achieve a successful installation?
>
> Thanks in advance for your help!
>
> Lou (I have also posted this to the LAK17 Yahoo Group.)

Why bother with a compass, you don't need one unless your cloud flying
Glen

On Saturday, August 15, 2015 at 8:04:43 AM UTC-4, wrote:
> On Friday, August 14, 2015 at 8:52:17 PM UTC-4, MNLou wrote:
> > I am trying to install a Precision Vertical Card Compass in my LAK17at.
> >
> > My first attempt was in the instrument panel. That didn't work due to too much magnetic interference from the various speakers "under the hood".
> >
> > I then moved the installation to the top of the left side of the glare shield as far forward as possible. Again, there is too much interference - source unknown. Could be magnetic, could be metal.
> >
> > My next attempt will be to move the compass again and add some shielding to try and mitigate the interference.
> >
> > Any good ideas on how to achieve a successful installation?
> >
> > Thanks in advance for your help!
> >
> > Lou (I have also posted this to the LAK17 Yahoo Group.)
>
> Why bother with a compass, you don't need one unless your cloud flying
> Glen

On some gliders Minimum Equipment List.

Lou,

There's a lot of steel around the sides of the glare shield in my
LAK-17a. My compass (assumed factory installation) is at the center and
as far forward as possible (goes away when the canopy is jettisoned).
My GPS antenna is located on the top of the panel quite a distance from
the compass (stays with the ship when the canopy is jettisoned).

Dan

On 8/14/2015 6:52 PM, MNLou wrote:
> I am trying to install a Precision Vertical Card Compass in my LAK17at.
>
> My first attempt was in the instrument panel. That didn't work due to too much magnetic interference from the various speakers "under the hood".
>
> I then moved the installation to the top of the left side of the glare shield as far forward as possible. Again, there is too much interference - source unknown. Could be magnetic, could be metal.
>
> My next attempt will be to move the compass again and add some shielding to try and mitigate the interference.
>
> Any good ideas on how to achieve a successful installation?
>
> Thanks in advance for your help!
>
> Lou (I have also posted this to the LAK17 Yahoo Group.)

--
Dan Marotta

On Friday, August 14, 2015 at 5:52:17 PM UTC-7, MNLou wrote:
> I am trying to install a Precision Vertical Card Compass in my LAK17at.
>
> My first attempt was in the instrument panel. That didn't work due to too much magnetic interference from the various speakers "under the hood".
>
> I then moved the installation to the top of the left side of the glare shield as far forward as possible. Again, there is too much interference - source unknown. Could be magnetic, could be metal.
>
> My next attempt will be to move the compass again and add some shielding to try and mitigate the interference.
>
> Any good ideas on how to achieve a successful installation?
>
> Thanks in advance for your help!
>
> Lou (I have also posted this to the LAK17 Yahoo Group.)

Lou,

You might try this, it has worked for me on an old Aeronca as well as on modern ships.

Center the compensating magnets that are built in to the compass. Temporarily install the compass in the most desired location using non-magnetic screws (hint, you can paint SS screws black etc. or use brass).

Turn glider to the heading that will maximize compass error. Using a suitable bar or rod magnet (not a horseshoe or circular type) orient and position the magnet (using double sided tape or other temporary means) to the side of the compass and far from the compass as possible while still having the magnet neutralize the compass error.

Check the other cardinal directions for error as well. If the error is great on any heading, compromise the original magnet position to minimize error in both headings if need be. Some error is okay, it's just preferable to even it out as the compass is swung.

Now proceed with the normal compass swinging procedure using the built in compensating screws.

Don't forget to more permanently mount that magnet with hot melt glue or epoxy putty etc. Not good to later find that magnet on the floorboard.

bumper

On Saturday, August 15, 2015 at 8:05:47 AM UTC-6, Dan Daly wrote:
> On Saturday, August 15, 2015 at 8:04:43 AM UTC-4, wrote:
> > On Friday, August 14, 2015 at 8:52:17 PM UTC-4, MNLou wrote:
> > > I am trying to install a Precision Vertical Card Compass in my LAK17at.

Any chance you can relocate the speakers? When I redid the panel in my ASW15 to install Flarm and an LX8080/V5 I put the vario speaker back in the baggage shelf where the radio speaker was already located (the old Peschges vario had the speaker mounted right on the computer unit behind the panel). The PAI compass was able to be swung to within limits with the old setup but with the vario speaker back in the baggage area it ended up with almost no deviation.