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Master Mariner
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Discussion Starter #1
A few months ago I replaced the paddle wheel on the ST-60 speed transducer with one (seems to be new) from an old transducer I found in a box aboard. As it never worked before I did this, I had hopes that it might be an aid in current calculations, but it seems to consistently run 1.5 to 2,25 knots slower than the Gps.
Obviously, the current can not be as consistent as the error on the unit, so there must be a problem. It turns easily, just by blowing it, so it's not binding up or fouled.
Are all the paddle wheels the same; they appear to be identical? Does the ST-60 speed unit have a way to calibrate it?
 

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The ST60 'bi-data' speedo/depth meter has an apparent specific upper limit when in 'calibration mode' that often times is unable to correctly match actual boat speed (paddle wheel speed). Ive asked Raymarine support a few times about a physical correction (resistor, capacitor etc.) and no one there seems to have a 'work around', especially for a boat that has a deep forefoot and with the ST60 mounted away from the boats centerline.

So, if your boat has a BIG thick keel and the ST60 sits anywhere in the 'stagnation zone' in front of the keel ... the only thing Ive been able to remedy this is - a damn 'correction card' of ST60 output speed vs. REAL speed.
 

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A few months ago I replaced the paddle wheel on the ST-60 speed transducer with one (seems to be new) from an old transducer I found in a box aboard. As it never worked before I did this, I had hopes that it might be an aid in current calculations, but it seems to consistently run 1.5 to 2,25 knots slower than the Gps.
Obviously, the current can not be as consistent as the error on the unit, so there must be a problem. It turns easily, just by blowing it, so it's not binding up or fouled.
Are all the paddle wheels the same; they appear to be identical? Does the ST-60 speed unit have a way to calibrate it?
The speed calibration procedure is on pages 26 and 27 of the ST60 manual.
 

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Master Mariner
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Discussion Starter #4
The ST60 'bi-data' speedo/depth meter has an apparent specific upper limit when in 'calibration mode' that often times is unable to correctly match actual boat speed (paddle wheel speed). Ive asked Rayamarine support a few times about a physical correction (resistor, capacitor etc.) and no one there seems to have a 'work around', especially for a boat that has a deep forefoot and with the ST60 mounted away from the boats centerline.

So, if your boat has a BIG thick keel and the ST60 sits anywhere in the 'stagnation zone' in front of the keel ... the only thing Ive been able to remedy this is - a damn 'correction card' of ST60 output speed vs. REAL speed.
Sounds like you've probably hit on the problem; "So, if your boat has a BIG thick keel and the ST60 sits anywhere in the 'stagnation zone' in front of the keel", because that sounds about right. Since I have a transducer and room in my network to install the Garmin log, I doubt I'll put in the time and effort to make up a "damn 'correction card'". What a shame to have that unit right there at the helm, but unusable.
Don't we all love the Rayamarine support staff? Let's give them all a big cheer.
 

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"As it never worked before I did this,"
If the PO improperly installed the transducer in an area where it can't get clear waterflow...that's not Raymarine's fault. They're not entirely angels, but since they didn't install the paddlewheel, you can't really blame them if it has to be moved in order to work properly.
 

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The op seemed to ask whether you could calibrate the transducer at all, he didn't say he was maxed out on the correction factor.
 

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Discussion Starter #7
"As it never worked before I did this,"
If the PO improperly installed the transducer in an area where it can't get clear waterflow...that's not Raymarine's fault. They're not entirely angels, but since they didn't install the paddlewheel, you can't really blame them if it has to be moved in order to work properly.
I have tried to work with RM support many, many times, though not on this. Even on a $150,000.00+ commercial system, at many $ per hour from far away on the phone, they were less than helpful.
My comment was in relation to RichH's "Ive asked Rayamarine support a few times about a physical correction (resistor, capacitor etc.) and no one there seems to have a 'work around'," NOT the placement of the transducer.
My last effort was when I tried to purchase an autopilot motor from them, but they would not give me the hp of their motor; not could not, WOULD NOT.
In my experience, they are a lousy company with little interest in their customers and in fixing faults in their products. You can defend them all you please, but I would not install one of their products on any vessel I was operating, if they gave me their product and paid ME!
 

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These days, no major corporation puts the engineers on the telephone, sadly. Or helps customers to modify circuits beyond "adjust that trimpot", if that much. I agree that it would be nice if they DID go that extra mile, but unless you find a really small company where the guys who answer the phone aren't firewalled by lawyers and accountants...that's not unique to ray-ma-whoever they are calling themselves this year.

I've found their phone support to be reasonably courteous and prompt and on-point in the past, but then again, I haven't asked them to do anything beyond what a customer normally would need assistance with. Modify the circuit? Who knows, who designed it, where it came from, how old it is, whether anyone is intimate with it beyond the usual r&r by the book these days?

The only time I asked them to do anything unusual, was when they were changing names and we had half the displays with Raymarine stenciled on them, and the other half with Raytheon still on them. I called up and asked nicely if they didn't think we'd both look better if they all said the same name, whatever name that was, and they just shipped out a whole new set at no charge. Most corps would have offered to sell us new ones.

Modify a circuit? Track down an engineer and have him invest an hour or two in seeing IF the mod is even possible, when the problem is incorrect installation? Just doesn't same so unreasonable to me, that such a big corporation can't be that flexible, or spend that much money on it.

If it is in the wrong location, there's no guarantee that a modification in the circuit would help, since the error might not even be linear. Most reliable solution would be to place the transducer properly, rather than start hacking up the circuit with no assurance that it would work properly over a whole range afterwards.
 
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