[CA] [CA11] ST60 wind, tested voltage

[506sailingjim]

I have a ST60 wind instrument that is not working, I'm not sure if it is the wind vane or the instrument (gauge). It will not show direction of wind and will not linearize.
I jumped out the instrument and but left the R wire which has 8 volts going to mast top, from Blue to shield I have 7.62 volts and on Green I have 7.40 volts. I understand the voltage should be between 2 and 6 volts.
I'm assuming this test indicates that mast head unit is the problem, since I have correct voltage going up but, out of spec. readings coming down to instrument, is that a correct assumption?
Thank for any help
Jim

[Chuck - Raymarine - Moderator]

Jim,

Please click here to view a FAQ addressing this subject. This FAQ calls for performing three voltage measurements. As you have suggested, should any of the measured voltages deviate from those specified within FAQ (they do in the case of your wind transducer), then it would indicate a fault within the transducer, necessitating that the wind instrument be sent to Raymarine’s Product Repair Center to be bench checked / serviced.

[mauruuru]

Using this information to test my ST60+ wind instrument and xducer I had strange readings so went a bit further. From this info can you tell if it is only the display unit or both display an xducer requiring replacement:
Display and cducer connected
R-Shield. 7.96 V DC
G-Shield. 5.6 V DC
B-Shield -0.03 V DC
Y-Shield. 3.6 V. AC

Windvane Cable only
R-S. 21.6 k ohms
G-S. 38.6 k ohms
B-S. 6.1 ohms
Y-S. 65.4 k ohms

Display Only powered on
R-S. 7.96 V DC
G-S. 0.001 V DC
B-S. 0.001 V DC
Y-S. 8.0 V DC

[Chuck - Raymarine - Moderator]

mauruuru,

Based upon the first set of voltage measurements performed, the masthead transducer is in need of service or replacement. The ST60 Wind Instrument Display may not be tested in the manner suggested. Instead, it would be tested by interfacing it to an operational wind transducer.

[saucur]

I am getting wind direction but not wind speed getting 0.0 wind

these are the readings I get
Display w/ ducer connected
all good except Y to shield are 7.56volts

Windvane cable
R-S 19.8 K ohms
G-S 27.5
B-S 26.7
Y-S 29.0

Is this telling me my wind instrument needs replacement?

Curt

[Chuck - Raymarine - Moderator]

Welcome to the Raymarine Forum Curt,

As indicated within the FAQ found here, the masthead transducer's yellow and shield leads are used to test the speed sensing circuity of the transducer. Should the voltage not fluctuate as the cups are rotated in the manner specified within the referenced FAQ, then the wind transducer would be deemed to have suffered a failure.

[MThackray]

I have a ST60+ Wind Instrument (both master & slave). They indicate wind direction correctly but always indicate apparent wind speed as 0.0.

As per the debug instructions, I checked the voltages as the mast step junction box. Using an oscilloscope, the voltage between Yellow and Shield is a square wave, as expected, but oscillates between 3V and 7V, i.e. it appears to be offset by about 3V.

What could cause this?

I am looking to gather the best data before climbing the mast to remove the transducer, should that be the issue.

Regards,
Mark

[Chuck - Raymarine - Moderator]

Welcome to the Raymarine Forum Mark,

Testing for speed voltage would typically require that the transducer's cups be rotated slowly by hand. However, should the oscilloscope have been able to freeze the squar wave and should you have observed the voltages reported, then it would indicate a failure within the masthead transducer's speed sensing circuitry necessitating that the transducer be unplugged from its masthead base and sent to Raymarine’s Product Repair Center to be bench checked / serviced.

[tthackray]

If anyone is interested here are the voltages I measured on the bench for a new Raymarine windvane connected to an ITC-5:

Raymarine Windvane
Input 8V
Angle Blue Green
0 3.92 5.69
30 4.86 5.45
60 5.49 4.86
90 5.76 3.9
120 5.5 3.04
150 4.84 2.42
180 3.95 2.18
210 3.07 2.43
240 2.42 3.05
270 2.17 3.93
300 2.42 4.81
330 3.1 5.46
360 3.92 5.69

The attached image is a plot of the above values.

[Chuck - Raymarine - Moderator]

Noted.