NASA sounder (Duet) gone mental

[Amulet]

The sounder on my Clipper Duet is flittering randomly around the 30 metre mark in two metres of water. First test since relaunch. Not unheard of before, and mucking around with the "threshold" setting usually sorted it. Have tried every possible threshold with no improvement. Any ideas?

It does say in the manual that antifoul on the transducer could cause problems. Surprises me. Given that you can glass a transducer inside a GRP hull, it seems unlikely that a coat of paint could be such a problem. However, it is possible that the yard could have slapped antifoul on it.

Anyone seen this?

 

[blackbeard]

How is the transducer mounted? A common method is to glass-in the holder and use a fluid of some description to fill the space between transducer and hull. If some of the fluid leaks away, leaving an air bubble, you will get some very odd depth readings.

 

[Fascadale]

The depth sounder on my clipper duet was also erratic.(to say the least)

I tried it with a new transducer. Still erratic.

I sent it back to Nasa, they tweaked its electronics, or something, now it works.

£35.

Lets just hope it keeps working

 

[Amulet]

How is the transducer mounted? A common method is to glass-in the holder and use a fluid of some description to fill the space between transducer and hull. If some of the fluid leaks away, leaving an air bubble, you will get some very odd depth readings.

Nope - wooden boat and sounder through hull. The most that can be between it and the water is antifoul.

 

[lw395]

Nope - wooden boat and sounder through hull. The most that can be between it and the water is antifoul.

In that case, all you can really do is check the condition of the cable and the plug into the instrument.
Maybe you can borrow a spare sensor to test the instrument head, but it sounds like packing it off to Nasa is where you are heading...

 

[Amulet]

In that case, all you can really do is check the condition of the cable and the plug into the instrument.
Maybe you can borrow a spare sensor to test the instrument head, but it sounds like packing it off to Nasa is where you are heading...

I have another transducer so that is what I'll do. Spoke to Mr Nasa today - he seemed puzzled by the symptoms.

 

[j24jam]

I also had this problem - turned out that you have to be careful with what you have between the transducer and the hull....sikaflex does not work! which i why mine didnt. I was recommended using chewing gum! or buying the mounting kit which comes with a suitable fluid...needless to say i went for the 60p option

 

[Amulet]

I also had this problem - turned out that you have to be careful with what you have between the transducer and the hull....sikaflex does not work! which i why mine didnt. I was recommended using chewing gum! or buying the mounting kit which comes with a suitable fluid...needless to say i went for the 60p option

As I said, this doesn't apply. The transducer goes through the (wooden) hull. There is nothing but some antifouling between it and the water. The Nasa guy didn't seem to think that this was the problem.