Originally Posted by xort
We kept loosing windexes so we rely on the instrument.
I like going up the mast, as long as there are no big rolling wakes trying to throw me off!
Yesterday we had a whopper of a wake come rolling in from a big yacht...luckily it was 5 minutes after I came down!
We've had our best luck calibrating the indicator by taking the yacht out on a relatively light air day and motoring directly into what wind there is at our top speed. We do this on the river where we're moored, rather than in the near-by bay, to minimize the effect of wave action on apparent wind and with that, can get pretty accurate. An alternative is to go to the masthead, manually hold the pointer in place first forward and then aft, and have a helper set the calibration on the instrument itself. One can then also check the linearization of the unit itself as a 180º change at the masthead should be reflected, exactly, on the instrument. If it is off somewhat, one can go through the linearization process a second time; or, one can do alternating calibration corrections, from forward to aft and back, by removing 1/2 of the error each rotation, in each direction.
N'any case, good luck. You've got the device working again and hopefully that will last for awhile.