[TG] [TG11] Analogue Wind Display instability with rotation sensor

[Tom - Raymarine - Moderator]

Hi Nick,

Quote:The mast rotation calculations can use the data from the EV unit - just yesterday, I disconnected the CHT to see if this had an impact on the problem, and, while the calculations were clearly still working using the EV data via the T122[/quote
The information that I had been given was that Mast Rotation would only work with compass data from a Hull Transmitter, not EV heading through a Microtalk, but the colleague who gave me that information has left the company and I don't have the time to test if for myself. If it's working for you, very good. The EV's heading data will be much better than any fluxgate.

[quote]There is a possibility that I have switched my wind display into true wind mode and not noticed - in the absence of a STW input, would this make the wind direction reverse?

STW missing completely would prevent the calculation of True Wind, but incorrect STW will give incorrect TW. In certain circumstances (e.g. motoring downwind) STW reading zero will give inverted TWA, but not in all circumstances. It's just something we need to eliminate.

Quote:if the MRS fluxgate had an intermittent open circuit, wouldn't the rotation calculations completely fail at that point?

I've never tested an MRS with failed flxugate, but failed pilot fluxgates can give a heading which toggles between a correct and incorrect value depending on whether you're within or outside the 'dead sector' that's a typical symptom of this kind of failure. It wouldn't give exactly the symptoms you describe but I am always careful of interpreting symptoms over-literally, we see a lot of apophenia in the problems reported to us.

Unless there is a good reason otherwise, I would always advise only having a single source of heading in your system and the EV will give far better heading data than the fluxgate. If you were going to disconnect something, the one I would disconnect would be the fluxgate from the hull transmitter rather than the EV.

Regards,
Tom