ST40 Wind calibration

[SteveA]

I tried calibrating this on Sunday when there was only a very light breeze but every time I started the linearise part after only about half a turn the thing started beebing at me - could it have been there wasn't enough breeze for it?
Also can anyone explain what this linearising does? and am I right in thinking that when I then go to the alignment bit I need to have the boat exactly into the wind?

 

[doug748]

I hoped you would get a response to this Steve, cos I fitted one about 6 years ago and it's still a mystery to me. The handbook is full of instructions and no explanations. Let me know if you make any progress. Brian.

 

[SteveA]

Brian,

Since I've had no joy on here I'll contact Raymarine direct and see if they can point me in the right direction - if I learn anything I'll let you know.Steve

 

[Emjaytoo]

I put a new one on my previous boat last year. We spent hours going round and round in bloody circles and couldn't get it to work accurately - anything upto 120 degrees out, so just gave up.

However, over a period of 3 or 4 months it got progressively more and more accurate. In the end it was spot on!

But as you say, a complete mystery! /forums/images/graemlins/confused.gif

 

[wiggy]

Is this on a sailing boat? Only asking because I was looking into ST40 wind, is it the one with the rotavecta at the top? Can anyone tell me if they are any good for sailing boat and what is the main drawback compared to othe rtypes of can and cup jobies, are they accurate etc?

 

[pvb]

Linearisation...

The wind could have been too light - there's mention in the manual of there being a range of wind speed needed, but it doesn't say what it is. It does appear that you can skip the linearisation part of calibration and go straight to alignment. You don't need the boat exactly into the wind, you can set an approximate wind angle based on observation and fine-tune it some other time.

 

[Emjaytoo]

The one I fitted had a rotavecta. Perhaps why I had so much trouble with it!

 

[doug748]

Yes, mine has the rotavecta. It has proved to be robust and reliable. Seems reasonably accurate but then again I don't use it a lot, and directional accuracy is limited by the fairly basic display. I seem to recall when fitting it, that the vane unit and cable are bonded so if you had problems the whole lot would have to come out...

 

[SteveA]

Ours is on a sailing boat - given the choice I would not have got this type. The more normal type withe cups and a wind vane seem to be far better. We had ST60 instruments on the last boat and had no problems with them - and no need to carry out some strange calibration techniques!
I've raised queries withe Raymarine about the way to calibrate and will post their reply.

 

[SteveA]

I've just had the reply from Raymarine which says:

"Linerising the wind unit just lets the unit learn what is around it, it can do this automatically when you switch it on. When you align it just point your boat forwards and it should be fine."

 

[Emjaytoo]

Which is why ours probably sorted itself out over a period of time.