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

[artemidorus]

Hi Tom,

Thanks for your assistance.

I think that all of my observations pertain to apparent wind direction. In addition, I don't tend to insert the speed/ depth hull instrument into its tube for day trips, as the tube has lost its valve and lets an undue amount of water into the bilge when the instrument is inserted or removed. I rarely choose to use a true wind display. 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?

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, it did not stop the intermittent flipping of the needle. The original deviation calibration was not carried out with the EV (as far as I can tell so far, it is impossible to calibrate deviation with the EV input).

I am intrigued by your suggestion regarding the MRS fluxgate, but I note that the needle, when it flips to the wrong direction, always appears to flip exactly 180 degrees, and can still be used by the helmsperson in inverted mode. The mast rotation calculations still seem to work, just with a 180 degree error in the output. When it flips back to the correct orientation, it also flips exactly 180 degrees. Correct me if I'm wrong, but if the MRS fluxgate had an intermittent open circuit, wouldn't the rotation calculations completely fail at that point?

I will follow your advice and trial a disconnection of the STNG from the Micronet to see if the Micronet-only system functions as it should.

Regards,
Nick.