NASA Clipper Duet Depth Log spurious readings

[VicMallows]

You first need to determine if the problem is noise being introduced by the wind instrument into the DC supply feeding both; or whether it is radiated interference from one instrument to the other. Another cause could be that the transducer cables to the two instruments run very close together .....try separated them.

Start by temporarily connecting the new instrument directly to a 12v battery. If everything is now OK you will either have to run a separate DC feed to the new instrument, or start playing with filters (capacitors; ferrite rings; etc). If that is not the issue you will have to start looking at radiated intererence from the wind instrument

 

[VicS]

It might be worth giving Nasa a call.
They have a reputation for being helpful if contacted and it will either be something they are familiar with .... or fascinated to hear about.

 

[rocky-]

Hello,

Thanks for the suggestion, I also had contacted Nasa, they told the same, that it can be some interference.
However when we arrived with my electric mechanicer friend to track down the issue, it was gone as it was never existed before.
So both instrument is working now well.
One new issue occured, the wind instrument has no backlight at all. I can see the ILLUM settings on the bottom left corner of the display, I can change it from 0-9 as well, however there is no backlight on the display at all (we tried during night...)
Anyone has any idea, what could be the cause of this? I also will contact NASA again, about this.

Regards,
Krisztian

 

[Stemar]

No backlight would have me checking the LED and looking for dry joints in the circuit, but I'm crap at electronics, so it'd probably end up going back to NASA

 

[Gwylan]

we found it was all in the setup. Had some terrifying moments when suddenly the depth would go off in an area we were nor certain about.

Sat at anchor, dropped the lead line over the side in about the same place as the transducer and checked the depth. *
Then reset the ping rate and some of the other settings in the NASA 'engineering mode' and everything has been fine ever since.
The 'engineering mode' is in the instruction booklet that NASA produce with their John Bull printing kit.

*hint - if you are doing your YM, or whatever they call it today, make sure the examiner sees you do the depth over both sides of the boat.