As a follow-up to this, the above tests are as written by Raymarine, but in my opinion are misleading.
See my topic ST60 Wind Instrument Information
As a final note on this thread,: although working, I was getting the needle reading 120deg off the actual wind direction, e.g. wind directly ahead, needle points 120 stbd; wind behind, needle 60deg port. To me, that bears out Nigel's comment about signal rather than voltage in his topic above (although definitely 120 deg rather than 90deg!). It's easy to fix - go into DLR mode/analogue calibration, and move the pointer as required. It's damped so should be done slowly to catch up. It doesn't even require the boat to be moving into wind as stated, you can adjust the needle to the hawk (in my case, 120deg). Everything is working like new so perhaps there had been a minor problem that was exacerbated by the fiddling about during mast removal ops. Now all I have to fix is the speedo...