NASA Clipper depth - Part 2

[Rowana]

Well, I was up at the boat this afternoon and had a fiddle about.

Stuck transponder next to my ear, and it's definately clicking - and no, it didn't find the depth of my brains! When I hold my little tranny radio up to the display head, it picks up the clicks. All the other functions appear to work.

Still showing "out", so it looks like the display unit is u/s.

Are they worth repairing, or is it a case of buying a replacement?

Who repairs them anyway? Do they have to go back to NASA?

 

[Mudplugger]

Give them a bell, normally pretty helpful.

 

[alisdair4]

My last NASA expedition cost me £50. The head (panel) and transducer came bag, working 100% -cost £50. Difficult to beat, IMHO.

 

[Danny]

When mine gave the same symptoms I took it in to Nasa at Stevenage (obviously not an option for you) and found them most helpful. They re-tuned the instrument head and sold me a new transducer at a reasonable price. I also picked up loads of useful information about echo sounders, theoretical and practical, including a neat idea for a test rig.

I found them very helpful, friendly and informative.

 

[captainslarty]

Hi
Please let me know the neat idea for a test rig.
Many thanks
Joe

 

[Danny]

[ QUOTE ]
Hi
Please let me know the neat idea for a test rig.
Many thanks
Joe

[/ QUOTE ]Hi Joe. The test rig consists of about a yard of plastic drain pipe of suitable diameter (not too large but greater than the diameter of the transducer head) cut neatly at each end. Cover one end with pretty much anything flat - a piece of plastic, perhaps - stretched over the end. Poke the transducer in the other end and wedge it with a bit of foam or something for convenience. The e/s should show a depth (with no offsets) about 4x greater than the length of the pipe.

It works because, although the transducers are inefficient in air, the sides of the pipe make up for this. The depth shown is in relationship to the speeds of sound in water and air. (About 4x faster in water than air).