ST60 Wind Transducer - What does this Test Show?

[senormechanico]

sIf you have the transducer unplugged and the masthead socket is "empty", and there's a deck connector that's accessable, I have one more suggestion to try.

Disconnect the wires going up the mast from the wires going back to the instruments, or disconnect the instruments from the wiring harness which goes up the mast.
The point is, you need to connect an ohmmeter to each wire and come up with an infinite resistance to each other wire AND mast ground. Anything other than an open circuit would be salt and moisture with a 99.9% chance of it being at the masthead or the deck junction. The deck junction should be easy to check for salt and /or moisture. If you can disconnect the masthead wiring at the deck, you can easily narrow down any leakage to (almost surely) the masthead socket connections.

If you get any resistance less than ten megohms, suspect salt.
When you said you cleaned it and it worked off and on for a bit, I suspect you diluted salt. WD40 often works for this if you are really liberal with it.

One more thing. If you can remove the circuit board from the transducer and you see any salt residue, clean it with warm water and a tooth brush. You won't hurt anything on the board. Let it dry thoroughly.

As a retired electronics tech, I've repaired lots of VCR's with hot water and even put individual circuit boards through a dishwasher to get rid of spilled soda pop residue (tons of salt in soft drinks).

[RJV]

Not sure if you saw my post #11 and #12 above as I feel the test detailed there proved the integrity of the mast head socket and in-mast wiring. In any event, I have just repeated and extended the test to be doubly sure.

There is a junction box at the mast base accessed by removing a ceiling panel in the cabin. See photos. This junction box links the 5 wire cable coming down the mast to a 5 wire cable that connects to the master ST60+ Wind display. The junction box is in pristine shape - there is no sign of any water or corrosion and I am absolutely confident that the junction box connections are all perfect.

At this junction box I disconnected the 5 wires coming down from the mast and used a multi meter set to the max (2 Mega ohms) and then tested all possible pair combinations and then each of the wires with respect to the mast and in all cases got a result of infinite resistance. This proves to me that there are no shorts between any of the 5 wires, between any wire and the mast, or between any of the 5 pin sockets in the mast head socket.

After this, and with the 5 wires coming down from the mast still disconnected, I then turned my nav instruments on to conduct some voltage checks at the junction box connector. So what I am testing for is any power being supplied from the master ST60+ Wind display towards the junction box.

Red to shield was 8.01 volts (= what I expected)
Blue to shield was 0 volts (= expected)
Green to shield was 0 volts (= expected)
Yellow to shield was 7.94 volts (a bit surprised by this, I kind of expected 0 volts as I thought the transducer would be generating the voltage on this wire. Maybe this is OK .... the display put a fixed voltage on the yellow and the anemometer also puts a variable voltage on this same wire and the display displays a wind speed calculated from the aggregate voltage).

And with the 5 wires coming down from the mast still disconnected, I then checked each wire's voltage against the mast (instead of the shield) and got the following results :

Red to mast was 7.1 volts
Shield to mast was -0.9 volts (note the negative)

Not sure why there is a difference between shield and mast .... is this just my galvanic protection or anodes at work?

So I'm still thinking that the transducer circuit board is faulty, and that the two ST60+ wind displays, the wiring between transducer socket/junction box/displays are all good.

What do you think?

[senormechanico]

The +8 volts on the yellow wire comes from the display. It's a high impedance source and the anemometer has an optical isolator which "chops" that voltage with a photo transistor to make the signal on the yellow wire. That's normal.

It really does seem that you've eliminated every possibility but the transducer board. (probably IC4)

[Dos Gatos]

You can send your unit in for an out of warranty repair (replacement)

cost is as follows from their website:

R28170

Short Arm Masthead Wind Transducer

$185.00

R28171

Long Arm Masthead Wind Transducer

$350.00

Z195

Rotavecta Wind Transducer

$185.00

[RJV]

Originally Posted by Dos Gatos

You can send your unit in for an out of warranty repair (replacement)

cost is as follows from their website:

R28170

Short Arm Masthead Wind Transducer

$185.00

R28171


Long Arm Masthead Wind Transducer

$350.00

Z195


Rotavecta Wind Transducer

$185.00

Thanks for that, but with freight cost from Australia to the USA and return, and the time it will take (this is our sailing season now) a DIY is the better option even with some small chance that the new circuit board doesn't fix the problem.

[RJV]

Originally Posted by senormechanico

The +8 volts on the yellow wire comes from the display. It's a high impedance source and the anemometer has an optical isolator which "chops" that voltage with a photo transistor to make the signal on the yellow wire. That's normal.

It really does seem that you've eliminated every possibility but the transducer board. (probably IC4)

Thanks for that - that's very reassuring as I began to doubt the ST60+ displays.

I too think its the transducer circuit board, and probably IC4. The ebay seller of the circuit board is away for a few days so there's a short wait before he can ship me one.

I will make a photo record when I replace the circuit board and post them here to assist other forum member. I think this thread, with the schematics, diagrams, measurements, analysis and photos may almost be the "go-to" thread for others with similar wind vane behaviour.

Thanks again for your assistance.

[RJV]

I just chanced upon this document. I'm not promoting the product, but as the document contains some additional information on testing a wind transducer it adds to the body of knowledge in this thread for others.

[goboatingnow]

The dual axis Hall effect sensor is a Sentron 2SA-10 chip , it could be easily replaced though the SO product is no longer produced

The buffer amps in my opinion are more likely to have failed in my opinion


the 2SA-10 is given as a 5V part , which explains. All the farting around using the op amps to create a virtual 5V supply ,


Dave

[RJV]

It's fixed at last ! I replaced the wind vane transducer circuit board and reinstalled it at the mast top (after a successful bench top test) and I now have wind sped and direction displaying on both my master and slave ST60+ wind instruments. Hooray !

The Raymarine part number is A28164 and it cost me AU$110 locally, or about US$100.

Thanks to all for your advice and support. As promised, below I have posted 11 photos to show how to replace the circuit board. It is easy - no special skills required.

In the order of the photos :

1. Wind vane removed from mast.
2. Remove this small Philips head screw from anemometer and then pull the anemometer off the spindle shaft.
3. Remove this small Philips screw from wind vane and then pull the wind vane off the spindle shaft.
4. Exploded view. left to right : screw; anemometer; transducer pod; wind vane; screw
5. The two halves of the transducer pod can be separated by unscrewing by hand (normal counter clockwise thread). But if its a bit too tough on the hands, you can insert the two tips of a pair of needle-nose pliers into any two of the four indentations in the top pod to give "extra grip" on this pod half (four indentations visible in next photo).
6. With the two pod halves separated the circuit board is revealed. You can't see it in the photo, but there is a rubber o-ring on the thread to assist with weather proofing. Its unlikely that you need to replace it, but give it a clean and apply a little petroleum jelly or similar lubricant.
7. The circuit board is only snapped into the bottom pod half. Insert a fine tipped screw driver or something pointy into one of the two large holes in the circuit board to "flip" it out gently. Gently pull off the white cable connector noting its orientation beforehand so that you don't try to force it on incorrectly onto the new board.
8. The removed (faulty) circuit board. Note the numbers - this seems to be revision "D" of the board.
9. The new replacement circuit board - top side.
10. The new replacement circuit board - underside. Note the numbers - this seems to be revision "G" of the board.
11. The new board shown in the bottom pod half after having reconnected the cable. Make sure that the circuit board is snapped firmly into position around its full perimeter - see the small locating lugs etc., around the edge to ensure that its orientation is correct and that it is held firmly in position.

After this, screw the pod halves back together firmly and reinstall the wind vane and anemometer with the two Philips head screws. Note that the upper and lower spindle shafts have a flat face on one side to locate the anemometer and wind vane. Look carefully at these - don't force the anemometer or wind vane on, and don't over tighten the two Philips head screws. Make sure both the wind vane and anemometer spin freely and silently (not scraping on anything).

If you are confident in your handiwork then reinstall the transducer on your mast. Otherwise you can bench test your work with the aid of the schematics attached above, a 6 volt and 1.5 volt torch battery wired in series to give roughly 7.5 volts, some fine wire and a multi-meter. Make sure you apply the power to the correct pins else you will damage the new board.

Good luck.

[nigelmercier]

Originally Posted by RJV

6. With the two pod halves separated the circuit board is revealed. You can't see it in the photo, but there is a rubber o-ring on the thread to assist with weather proofing. Its unlikely that you need to replace it, but give it a clean and apply a little petroleum jelly or similar lubricant....

I suggest silicone lubricant rather than a petroleum based product.

Nice write up, did you clean and lubricate the bearings at the same time?

Regarding the test measurements, I think there is some confusion regarding the voltages. The (badly named) port and starboard signals are sine and cosine waves, in other words at 90 degrees to each other. They do not increase significantly in amplitude as the vane is rotated faster, it is their frequency that changes.

[RJV]

Originally Posted by nigelmercier

I suggest silicone lubricant rather than a petroleum based product.

Nice write up, did you clean and lubricate the bearings at the same time?

Regarding the test measurements, I think there is some confusion regarding the voltages. The (badly named) port and starboard signals are sine and cosine waves, in other words at 90 degrees to each other. They do not increase significantly in amplitude as the vane is rotated faster, it is their frequency that changes.

Thanks, yes, silicon lubricant would be the better choice. No, I did not clean/lubricate the bearings other than to spray the outside of both with WD40, air dry and then apply some silicon spray.

I'm aware that the weather vane voltage signals are sine and cosine waves and are 90 degrees out of phase with each other - this is detailed in the attachments I provided above. I referred to them only as port and starboard voltages to keep things simple as there is nothing to be gained (but potential to confuse) by referring to them as sine and cosine signals.

In fact the voltages (signals) do not increase in amplitude whatsoever with vane rotation speed - and I don't believe I stated this or implied this. The voltages (signals) change (increase or decrease) only when the direction of the vane is changed .... if the vane is steady, then so too is the voltage (signal). For any given direction, so long as the voltage is between 2 volts and 6 volts and varies with a change in vane direction then the wind vane direction part of the transducer is working properly.

With respect, I think it is unproductive/confusing to discuss voltage/amplitude/frequency when "rotating the vane". .... the vane indicates wind direction and in the field the vane will move about slightly as the wind direction changes but nobody really expects the wind vane to "rotate" at any real speed.

On the other hand the measured anemometer voltage (signal) does change when the anemometer cups are rotated. The transducer circuit board puts out two pulses per rotation (one at about 2 volts and one at about 8 volts) and a budget priced multimeter which checks voltages at set intervals will read some of these pulses and will miss others. For this reason the measured voltage could be anything between 0 volts at low RPM (multimeter misses all pulses) to about 5 volts at high RPM (multimeter sees most pulses and averages them). An expensive CRO would read and report all the pulses, but not many of us have access to such a CRO.

[nigelmercier]

Originally Posted by RJV

... I referred to them only as port and starboard voltages to keep things simple as there is nothing to be gained (but potential to confuse) by referring to them as sine and cosine signals.

In fact the voltages (signals) do not increase in amplitude whatsoever with vane rotation speed - and I don't believe I stated this or implied this...

I wasn't criticising you, or anyone else in the thread. Sorry if that was the impression.

My criticism is aimed at the original Raymarine documents, which does refer to port and starboard (which is meaningless) and does say that the vane voltage increases with speed.

[senormechanico]

Hooray for your success!
Where would we be without the internet?

[belizesailor]

Yes, thanks for the detailed thread. I have one to troubleshoot soon and will be refering back to this thread.

[RJV]

Originally Posted by nigelmercier

My criticism is aimed at the original Raymarine documents, which does refer to port and starboard (which is meaningless) and does say that the vane voltage increases with speed.

On a quick re-read I just don't see it written anywhere that the vane voltage (wind vane direction, not anemometer) increases with speed. Maybe I'm reading too quickly - but I just don't see it.