[Amel Yacht Owners] GPS Antenna below deck?


Ryan Meador
 

Fiberglass is mostly transparent to radio waves, so it should have only a tiny impact on signal strength.  But GPS (and any satellite) signals are already very weak, so it might be enough to cause you to "see" fewer satellites than you would with a clear view of the sky.  It shouldn't cause any position error.  Take care that your sensor isn't behind any metal or wood, or even some kinds of paint, which can block signals.

Ryan
SM 233 Iteration
Boston, MA, USA


On Fri, Mar 16, 2018 at 3:04 PM, sailor63109@... [amelyachtowners] <amelyachtowners@...> wrote:
 

In tracing down the wiring on the boat I've found another GPS antenna!


It provides position data to the ACR Nauticast B AIS.  It was installed in the ceiling space above the midship cabin (just fwd of the aft cabin), attached with silicone to the overhead, and it had fallen over and must have been rolling around up there in a heavy sea.


We've always had good results from the Nauticast so I'm likely to leave it there, unless there's a good reason not to?   Of course I'll improve the mounting situation.


I'd appreciate your thoughts.



Alexandre Uster von Baar
 

Good afternoon Duane,

sorry to read about your washing machine problem…

Regarding the extra GPS antenna, I had one at the same location.
More precisely as you remove the top access of the roof, it next to the big starboard winch, like a disc looking.
I was explained mine was in case of emergency (should I press an alarm in case of attack) this is how the ship would be tracked.
I did not continue the service as it was required to send the old antenna to be upgraded or reconfigured.
Then another was GPS antenna was installed next to that one, it was for the radio

Sincerely, Alexandre




--------------------------------------------

On Fri, 3/16/18, sailor63109@yahoo.com [amelyachtowners] <amelyachtowners@yahoogroups.com> wrote:

Subject: [Amel Yacht Owners] GPS Antenna below deck?
To: amelyachtowners@yahoogroups.com
Date: Friday, March 16, 2018, 2:04 PM


 









In tracing down the wiring on the boat
I've found another GPS antenna!
It provides position data
to the ACR Nauticast B AIS.  It was installed in the
ceiling space above the midship cabin (just fwd of the aft
cabin), attached with silicone to the overhead, and it had
fallen over and must have been rolling around up there in a
heavy sea.
We've always had good results
from the Nauticast so I'm likely to leave it there,
unless there's a good reason not to?   Of course
I'll improve the mounting situation.
I'd appreciate your thoughts.


Danny and Yvonne SIMMS
 

Hi.

Interestingly we had a near miss lightning event some years ago. An electrical surge came into the boat, a lot through the radar and the aerials. We had two identical backup Furuno digital GPS mounted at the nav station. The aerial for one was mounted outside on the rail, the other under the deck near the nav station. The one fed by the external was cooked, the internal aerial unit was fine. 

Another thought: On a previous yacht with much lower freeboard than the Amel we had a GPS aerial mounted internally near the nav station. Offshore in big swells it at times lost satellites as there were hidden behind the swells. (the South Pacific between New Zealand and the Pacific islands can haves BIG swells) By putting the aerial a little higher we overcame the problem. Obviously these satellites must have been near the horizon.

Regards

Danny

SM 299 Ocean Pearl  


On 17 March 2018 at 09:23 "Ryan Meador ryan.d.meador@... [amelyachtowners]" <amelyachtowners@...> wrote:

 

 

Fiberglass is mostly transparent to radio waves, so it should have only a tiny impact on signal strength.  But GPS (and any satellite) signals are already very weak, so it might be enough to cause you to "see" fewer satellites than you would with a clear view of the sky.  It shouldn't cause any position error.  Take care that your sensor isn't behind any metal or wood, or even some kinds of paint, which can block signals.

Ryan
SM 233 Iteration
Boston, MA, USA


On Fri, Mar 16, 2018 at 3:04 PM, sailor63109@... [amelyachtowners] <amelyachtowners@...> wrote:
 

 

In tracing down the wiring on the boat I've found another GPS antenna!


It provides position data to the ACR Nauticast B AIS.  It was installed in the ceiling space above the midship cabin (just fwd of the aft cabin), attached with silicone to the overhead, and it had fallen over and must have been rolling around up there in a heavy sea.


We've always had good results from the Nauticast so I'm likely to leave it there, unless there's a good reason not to?   Of course I'll improve the mounting situation.


I'd appreciate your thoughts.