autohelm log

[miket]

Dash mounted unit with matching depth sounder. ST something around 12 years old.
Sometimes reads perfectly agreeing with the Raymarine chart plotter SOG (no current). Other times steadfastly shows 0.0. Also, sometimes reads correctly and then starts to fall at 0.1 knots at a time until it reaches 0.0. Can also drop ay 0.1 knots at a time and then climbs back up to an accurate reading.

I ensured the paddle wheel was free, no anti-fouling on it and well sprayed with WD40 when out of the water in March. I have not yet removed the paddle wheel (plucking up courage), which is next on the list.

Boat is in fresh water in Holland with no visible fouling on the hull.

Any suggestions appreciated.

 

[Pye_End]

Sounds like a dodgy connector. The unit smooths the data so if the wheel stops talking to the display it takes a while to get to 0. Is there an in line connector, or it just the one at the display head?

Removing the log is no hastle, assuming you have the blank to go in the hole. You should be able to swap them over and only gain a cup full of water. Worth checking, but hard to see that this would be the cause of the problem.

 

[tillergirl]

I am sorry to say that that was the symptom of the failure of my transducer (Raymarine). But I would have a look at the paddle wheel first.