[DG] [DG11] ST60+ wind system: inaccurate / unstable wind readings

[NorthernLight]

Dear all,

I have a problem with a ST60+ Wind system, which is installed in following configuration:
- ST60+ Wind head display; Raymarine Wind transducer at mast top, junction at mast bottom
- ST60+ Tridata (with speed, depth, temperature transducers)
- Seatalk to STNG adaptor
- ES75 MFD
- Raymarine Evolution Autopilot EV-200 / p70S
- Lowrance radio (NMEA2000 – STNG via spur cable)

The readings of the wind angle are altering very quickly and are not stable, even in moderate wind situations. The reading of the speed often gives too high values; I already tried with calibration, but without success. The problem occurred last year after installation of the autopilot, no idea if there are interferences between the different devices).

I performed the tests of voltage metering, as describes in the forum (http://forum.raymarine.com/showthread.php?tid=97 ):

A) Voltages (DC) of ST60+ display head: (against shield, wind transduce not connected)
Red: 7,9V (normal value: 8V)
Blue / green: 0V
Yellow: 7,7V (is this OK?)

B) Voltages of wind transducer (only powered by 7,9V; ST60+ display not connected)
Red: 7,9V
Blue: 1,5 V … 5V (quickly altering) (desired value: 2V … 5.8V DC)
Green: 1,3 V … 2,6V (quickly altering) (desired value: 2V … 5.8V DC)
Yellow: 0,11 … 0,17V (not stable) (desired value: 0V … 5V DC)

C) Voltages of wind transducer; ST60+ display connected:
Red: 7,9V
Blue: 1,4 V … 1,8V (quickly altering)
Green: 2,0 V … 5,0V (quickly altering)
Yellow: 1,0 … 6,6V (not stable)

The wind transducer has been sent to and tested by Raymarine: no errors have been found.

It seems to be interesting, that the measured voltages significantly depend on the fact, if the transducer is connected (case C) or not connected (case B) to the ST60+ display. The wind had not changed very much during the time of the tests.

At the end: My question: Does the a.m. voltage measuring indicate a failure at the ST60+ head display? Or the cable in the mast? What is your proposal for further checks to find out the reason for the malfunction?

Thanks in advance, kind regards,
Hans

[Derek - Raymarine - Moderator]

Hi Hans,

Thank you for your enquiry,

The quickly changing voltages suggest that something is still amiss, it is quite possible that the mastcable of mounting socket at the top of the mast has some form of a short causing this behaviour.

We would suggest removing the transducer from the top of the mast, carefully inspect the socket at the top of the mast - any traces of green verdigris (corrosion) will point to a problem there.

You can make up a small lead with 1/8" spade connectors one end and a 5 pin DIN plug socket the other, this link here will identify the pinouts of the cable. Having made the cable, connect this direct to the rear of the ST60+ display and test again, if the unit tests out well, then this confirms a masthead cable/ cable through the boat fault. It could be interference being picked up by the cable for example.

If the fault persists, then it is likely there is still some issue with the masthead unit. It is unlikely to be the display because the transducer voltages are fluctuating and this is not related to the display itself.

Regardes
Derek