FA 50 AIS transmission

[Calpolygeno]

We have an FA50 AIS system that was newly installed. Initially we had issues with transmission. We replaced antennae and now are able to transmit. However, we have noticed a few things on local islands trips we will stop transmitting which can be fixed by turning power on and off. In slip we will sometimes transmit every few min but sometimes it’s over an hour. Looking at all the other boats they seem to transmit more regularly every 1-8 min or so.

Any ideas of where to start? We have our installers looking into it but it’s been a slow troubleshooting process so far with no solution. Maybe a connection issue somewhere?

 

[Johnny Electron]

Sounds like someone has placed the FA50 GPS antenna to close to another RF source or within the radar beam. Your GPS gets jammed and the FA50 quits transmitting. Most likely the same reason the previous antenna went bad. That is my best guess without seeing photos of the antenna mounting on the boat.

 

[Calpolygeno]

The AIS unit was replaced since the installers thought maybe that was issue. We have a new antennae. The same issue is still happening. I watch the other boats in the marina transmitting every few minutes and we sometimes are hours or not at all. We stop transmitting at times on trips.

We have a Cabo 40 express with a stainless steel tower. The unit is inside the tower dashboard. Could this all be interference from the stainless tower?

Anything we can do to solve this issue or is it just our boat? Any other units that may work better?

 

[Johnny Electron]

In the USA we rarely see any real problems with the FA50 other than antenna location problems. Sometimes you find people who use a VHF instead of a properly rated AIS antenna that have problems. I don't think I have ever seen the FA50 unit itself be bad. If you suspect the unit, your local distributor should be able to test it for you.

 

[Calpolygeno]

The unit was tested and reinstalled so I agree that isn’t issue. Is it possible it’s just our boat and stainless steel tower is issue or you think more than likely it’s a fixable issue and something isn’t right?

Who can we talk to next as our installer doesn’t have any more ideas.

 

[Johnny Electron]

If you put the antenna next to a mast, it would provide physical blockage no matter what it is made of. You can't change physics. If the whip antenna is close to the mast, I would relocate it. Without photos I really can't say.

 

[Calpolygeno]

Attached is a photo of the tower.

 

[Calpolygeno]

Another shot

 

[Johnny Electron]

Which one is the FA50 AIS whip and which one is the FA50 GPS antenna mushroom?