NASA Clipper Echo - faults

[Gwylan]

Suddenly the echo sounder has started giving all manner of faulty depth readings.

Have checked all the wires and terminations that I can get at and struggled through the instruction books.
The 'head' clicks, but not sure if that tells us too much.
All to no avail it continues to read about 1,5m with the ocassional moment of lucidity.

Anybody got any expereince, ideas?
Want to avoid a haul out to replacr the head if there is something that I have missed.

 

[ostell]

Weed or something over the transducer?

If if not a through hull bubbles in the liquid (or no liquid)?

 

[Gwylan]

Through hull - hull is too thick to work. Hence mounted on the oursied, thorugh the hull. Lots of resin! A real pain to replace - so need to be sure that is the fault before we haul out and replace the transducer.

Another NASA triumph - it costs me £150 for a haul out ot replace a £30 component. And the cups are dropping of the wind unit - that another £75 for a lift to the top of the mast or free beer to a couple of strong lads ot life me up in the bosun's chair. For £15 of cups.

 

[MM5AHO]

I have a continuing problem with my new NASA depth. Also installed through a thick hull.
I get all manner of readings and some of them make sense. The rougher the sea the rougher the readings, so I've assumed its was the transducer. Like you resetting that through the hull wasn't an attractive thought, so I procured another transducer and plugged it in, hanging the transducer over the side into the sea. This was in port, still waters. Still getting duff readings.
The display indicator shows "Depth" when it gets a good reading, and that disappears when its nonsense. Even with the new transducer its not good, with this word flashing on and off.
Back to sea again on another trip and to original installation, and I note that it sometimes reads about 1-1.5m, sometimes even zero, and stays there for perhaps 5 mins. Other times it acts almost sensibly and reads a believable depth. I've tried many combinations of settings (can adjust the sampling frequency and suchlike from menus). No improvements seen so far.
A call to NASA was friendly and willing, though not quite helpful. Interference was suggested. I'd thought of that too, so did experiments with switching on and off everything else. Wind charger, engine (alternator), other electronics etc etc. None of this makes any change.
So current thought is that the only common denominator is the display / controller. My next attempt will be to change that, and see what I get. Could it be faulty when new? Must be possible, so I'll try that.

 

[VicMallows]

Have you both made absolutely sure that the (cheap-and-nasty Belling-Lee TV style) connector is not the problem? Mine certainly plays up. Should replace it with something better, but just too lazy.

 

[Alpha22]

Had similar problems with mine on my old boat. Once almost ended up on a beach!! Was going in close to anchor for a few hours on a rising tide. Echo sounder said 10M. My friend in his boat close by radioed and told me he was only in 3M of water.... he was a bit further out than me!!! It also said "out" quite a bit..... I ended up replacing the LCD head with an old wherly gig unit. It was way easier to read!!!! Sold it with the boat and will never buy NASA again.....