NASA erratic depth sounder

[niallw]

I've got a NASA depth, wind, speed log setup. Ive learned to live with the broken windcups and fouled speed/log if only I could get the depth sounder to work reliably.

It sometimes reads OK up to about 8M, otherwise display E, or go blank and flash ---, other times in deeper waters it will jump around with random readings.

How to fault-find, any ideas. Do i replace the transducer itself or the viscous oil. Could the wiring be at fault.
Ive read on some other threads about hull thickness being an issue for these in-hull transducers. The GRP in my Nic 26 is around 3/4 to 1" thick. Im reluctant to put another hole in her for a through hull model, any other suggestions.

 

[ssjpiv]

Depth Sounder

Hi, I had a simiar problem with a sounder I wasnt conviced of, seemed to loose connection and give strnge readings.

You can contact NASA marine who will talk you throught lots of was of adjusting sensitivity etc (really nice people)

I found the topping up the level of fluid did the job!! Unscrew the top and top up with olive oil, woorke fine ever since.

Hope that helps.

 

[Seajet]

Yes, i was going to say the first move would be to check / top up the oil; it escapes surprisingly easily, some adhesives seem to go porous in contact with it.

I'd certainly not even consider a hole in the hull; my internally mounted Clipper Depth has always worked well, it's the only bit of NASA kit I've ever found worthwhile !