NASA Clipper Depth Sounder - testing out of water

[Poignard]

I have an unused NASA Clipper Depth Sounder that I intend to sell.

I have no boat to test it in and no deep water nearby.

When I connect it up to a 12v battery it all appears to work, and I can hear the transducer making a rapid ticking noise.

With the transducer in air it indicates a depth of '1.0 metres'.

With the transducer disconnected it indicates 'OUT'

Is this what you would expect a healthy unit to display?

 

[ChromeDome]

Seems ok but I think you'd have to test it in the right environment to get a reliable result.

Pond, swimming pool, lake, marina. Bring a battery and you'll know right away.

 

[Alex_Blackwood]

Seems ok but I think you'd have to test it in the right environment to get a reliable result.

Pond, swimming pool, lake, marina. Bring a battery and you'll know right away.

+1 looks OK. Have you got a wheelie bin you could fill with water or garden water bin?

 

[Poignard]

+1 looks OK. Have you got a wheelie bin you could fill with water or garden water bin?

I suppose I could fill a wheelie bin although that seems an awful waste of water.

 

[andsarkit]

Speed of sound in air is about 340m/s and in water 1500m/s.
If you point the transducer at a smooth hard wall or metal plate exactly at right angles you will get a reflection. It will read about 5 times higher than the actual distance.

 

[Poignard]

Thanks, I'll give it a try.

 

[Refueler]

The +1m may be offset programmed in by user .... ???

 

[B27]

I would hope that it read 'out' when the transducer was out of the water.
I have a bilge keel boat on a drying mooring, that's what my Nasa sounder says at low tide.
I think the transducer is poorly matched to air, so you get a very strong signal returned at zero time when the thing is out of the water.

If you set a keel offset, then you can get it to read various things in shallow water.

RTFM and buyer beware.

 

[Poignard]

[...]

... buyer beware.

If by that you mean anyone needs to beware of buying anything from me, I'd suggest you ask the dozens of people on this forum to whom I have sold things whether they have any reason to regret it.

If they haven't, I'll suggest an acronym for you - STFU.

 

[andsarkit]

I would hope that it read 'out' when the transducer was out of the water.
I have a bilge keel boat on a drying mooring, that's what my Nasa sounder says at low tide.
I think the transducer is poorly matched to air, so you get a very strong signal returned at zero time when the thing is out of the water.

If you set a keel offset, then you can get it to read various things in shallow water.

RTFM and buyer beware.

Indeed RTFM
'However, if the transducer has not been connected, or no echoes are received for any other reason, the word
DEPTH is not displayed and the unit waits for another five seconds before showing “out”'

You will not get a good reflection from mud in air which is why I said use a hard flat wall or metal plate. I have done this test numerous times with different echo sounders and it always works. There is no zero time reflection but you will not get much range - probably only a few metres.

 

[justanothersailboat]

For what it's worth, this 1m/OUT behaviour matches the way mine worked when I had to take it out and reinstall it. So I would think it has a good chance of being ok.

 

[madabouttheboat]

I suppose I could fill a wheelie bin although that seems an awful waste of water.

Do you have a water butt in he garden?

 

[Poignard]

Do you have a water butt in he garden?

No, but maybe one of my neighbours has.

Thanks for the suggestion.

 

[madabouttheboat]

No, but maybe one of my neighbours has.

Thanks for the suggestion.

If your'e going after the neighbours, maybe a fish pond could be found. It needs to be about 1m deep in my experience to get a decent reliable reading. ie a bucket doesn't work.

 

[Davy_S]

The only echo sounder i have owned that worked indoors was a Lowrance Eagle paper sounder, that would show the walls indoors! if you put a transducer in a bowl of water and put your hand underneath it and can feel it ticking and pulsing, you can safely assume it is working.