New Mainsail and New Wind Instrument.

DJE

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We did a shakedown sail around the Solent on Sunday to check all the new gear was working properly. Either the new wind instrument is under-reading windspeed or the new mainsail has dramatically improved our light wind performance. I expect we'll find out which it is in the first club race on Saturday. /forums/images/graemlins/shocked.gif
 

Richard10002

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My new Raymarine wind vane needs linearizing, and calibrating - have you done this if it's necessary?

I havent yet and, whilst the speed looks about right, the direction is 180 degrees out /forums/images/graemlins/smile.gif
 

DJE

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It's a Raymarine ST60. A new display unit connected to the existing masthead transducer. We did the linearisation and then set the direction (which was about 45 degrees out) and everything seems to be working OK but it just feels like more wind than it shows on the display. Sadly Bramblemet was down on Sunday so I can't do any direct comparisons but anecdotal evidence from other boats suggests that there was more wind than we were recording.
The old display unit kept losing its direction calibration so it went in to be tested and Raymarine declared it dead on arrival.
 

misterg

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[ QUOTE ]
We did a shakedown sail around the Solent on Sunday to check all the new gear was working properly. Either the new wind instrument is under-reading windspeed or the new mainsail has dramatically improved our light wind performance. I expect we'll find out which it is in the first club race on Saturday. /forums/images/graemlins/shocked.gif

[/ QUOTE ]

Don't get the silver polish out just yet - there's apparently a 20/25% difference in speed calibration between ST50 and ST60 (depending on which way you're going). The ST60 display lets you calibrate this out, so can be made to read accurate speeds from an ST50 masthead transducer, but the ST50 display can't be calibrated for speed, so will always over read if fed from an ST60 masthead transducer.

It must be true, I read it on the internet - here

Andy
 

DJE

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Both masthead and display units are ST60 and the new display unit was a direct replacement for the old one. £150 from a friend in the trade but this was old stock that he found; otherwise it would have been an ST60+ display and (from memory) £290. Just checked the manual and I can re-calibrate the wind speed if I need to. I'll gather a bit more data first.


The mainsail on the other hand was marvelous. I just had to beef up the adjustable outhall as the new sail is loose footed whereas the old one had a bolt rope. It's just a completely different shape and responds to the slightest tweak on the outhall or kicking strap.
 

misterg

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Sorry, I don't know why, but I had it in my mind that you had an ST50 wind transducer -Doh! /forums/images/graemlins/blush.gif

It may still be relevant, as the change in calibration happened at the ST60 version 6 (see here )

quote:

<font class="small">Code:</font><hr /><pre>Instrument Classic MHU New MHU
ST50*/ST60 prior to v6.00 1.00 0.75
ST60/ST60+ v6.00 and later 0.93 0.70

*As the ST50 Wind Instrument does not have provision for speed calibration, it will read 25% fast if used with the new-style MHU.</pre><hr />

Andy
 

DJE

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That makes sense. If the new display is calibrated to 0.70 for the new MHU I need to reset it to 0.93 for my old MHU.
That explains why it was reading 11 knots when it felt more like 15 knots. I'll have to delve into the realms of "Dealer Calibration" to check the setting.
 
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