i60 wind reads 2x too slow

[chyrne]

I just replaced my old ST60 wind, speed and depth instruments with i50/60. The new i60 display is attached to the original windvane transducer, commissioned 2004 (not rotavecta). The i60 now reads < 1/2 the actual true or apparent wind speed and calibration does not seem to help. It appears the anemometer is turning a bit more slowly than comps in the harbor but it is quite odd that the transducer would decide to fail at the exact time I replaces the display pack ( all displays working correctly including wind direction on the i60 wind instrument)
Any trouble shooting advice before I head up the mast?