New Autopilot Compass

[JLR]

Well, after calibrated the AP compass on my Simrad AP 20 successfully, I still have too large a deviation that is non linear. So, it can't really be corrected with the manual offset. And, to make matters worse, I have been unable to locate where the original owner placed the compass to check for random ferrous items. The result, the lollipop on my Furuno is off by quite a bit despite objects showing up where they should on the radar. So, I am adding a new flux gate for the pilot. The problem is that all directions I have read, as well as all prior installations I have done say NOT to put the compass on the bridge. The problem is that is about the only location within reason for me to put the new compass without tearing the boat apart. Assuming it is located along the centerline of the boat, how critical is it NOT to place it on the bridge? Also, does anyone know the damping recommendations for the AP 20 (4.5 secs, 6 secs or 14 secs)? The new fluxgate will be a KVH Autocomplete 1000. Thanks.

 

[racclarkson@gmail.com]

May be more critical to find original compass. I had the same problem. Finally figured out compass was fine until I started port motor. Then I got a 15 degree error or more depending on rpm. I moved the compass 3’ forward under the stairs and rock solid. I store my water and soft drinks under there for no interference. Earlier I had intermittent compass readings (and even a running compass) and traced to a hall of shame cable splice. You need to find your fluxgate first.

 

[Boatsb]

Newer systems are ok with the compass higher up like o the bridge but they use very different technology.

 

[JLR]

Thanks Scott. Would that include a KVH Autocomp 1000?

 

[Briankinley2004]

I found mine under the master suite bed. Had to remove a drawer to get to it. Way I found it was physically tracing wire from junction box. Everyone told me it should be under stairs but it wasnt

 

[lake of the woods]

My compass is under the forward stairs.

Mark
lake of the Woods
1989 40 DC

 

[Boatsb]

Thanks Scott. Would that include a KVH Autocomp 1000?

Maybe. I've not retro fitted one into a simrad system.

 

[Scarlett]

Hey Scott wasn’t the reason to mount it as low as possible due the exaggerated e,ffect of rolling the higher it was mounted, do the newer units have circuitry to negate this effect? John

 

[Boatsb]

Yes but sometimes theory is different from reality.

 

[JLR]

Found the compass in a hatch in the floor of a closet in the master. I'd say it was at least five feet off from the centerline of the boat. I moved it to a centerline location and will see if that solves my problem before installing the KVH I bought.

 

[racclarkson@gmail.com]

Found the compass in a hatch in the floor of a closet in the master. I'd say it was at least five feet off from the centerline of the boat. I moved it to a centerline location and will see if that solves my problem before installing the KVH I bought.

It's possible that threre's a splice(s) somewhere along the line. I had the a "non-linear" issue when I bought Aslan. Non-linear to me was a sometimes spinning fluxgate. Fixing the bad splices solved that problem.

To fix my linear issue (finite +/- a few degrees deviation), I had to move compass farther from the interference. In my case, port motor alternator moved me 15 degrees.

 

[JLR]

Thanks. I will recalibrate this week and see if the move made a difference.

 

[JLR]

Re calibrated this am and all is good. Now, what do Indo with the KVH Autocomplete 1000 I bought Any takers?