NASA Depth Sounder

[Joe_Cole]

Problems with my NASA sounder again. Last year it was sent back to the manufacturer who checkedit and said it was OK. It was OK (just) in the boat, but frequently gave wildly fluctuating readings, so I took it all with a pinch of salt.

This year the boat goes back in the water and I can't get any reading except "E". The handbook says that this means it's not receiving the return echo. I've checked all the obvious things, power supply, no obvious damage to the instrument or cable from the transducer. The transducer is mounted in board and there are no air bubbles in the mounting, and plenty of oil.

I'ld like to check the transducer. Can anyone tell me how to go about it? Or is there anything else to check?

Any help gratefully received.

Joe Cole

 

[marjepalma]

I had problems with my Nasa Clipper depth. It gave double the depth readings in the shallows!!!! Caught me out once when it showed 5ft and not 2.5. Thank goodness for bilge keels. Nasa took it back for "tweaking" but I never took it serious after that.

 

[rogerroger]

Put the transducer to your ear - you should be able to hear a faint clicking if it's working.



Roger Holden
www.first-magnitude.co.uk

 

[Guest]

You shouldn't need to put it to your ear, I can hear mine from a couple of feet away if it is pointed at me.

I thought "E" was engineering mode but I'd have to check my manual which is on the boat. I'm not impressed with my NASA Duet, the depth sounder is poor at best and the speed log under reads at all speed over 2.2k.

I presume you've checked the connection in the back of the instrument head?

Regards,

Peter
http://www.mistressofmourne.com

 

[muchy_]

You say that it is due to go back in the water? This could be why it is not getting an echo as the sound only travels through fluid and not air.

 

[Guest]

Love the Clipper hate the Target !

I bought a Target depth sounder some years ago on another boat........ and it never stopped hurting.

It was fine until you needed it, when depths are low, and it either doubled the real depth or defiantly stuck on around 2.5 metres.

The Clipper version has been great. Great big numbers and accurate to boot.

 

[milltech]

I cannot test the technology I sell, but I believe that where two component parts are involved it's quite a good idea to swap with a known working example and see which ends causing the problem.

You can do this either by borrowing a Nasa or Seafarer depth transducer, or you can buy one from me for £22.99 less 3% on line buyers discount = £22.30

Dangle it over the side and see if you get a better reading. If you don't it's the head unit, if you do it's the transducer or the installation. At this point you can decide, shall I return the new transducer or shall I keep it.

If you return it to me you will lose my postage, £2.95 and your return postage, but you might think a fiver is a cheap way to test or solve the problem. Finally, of course I would want it back in the condition I send it and not covered with gooey oil from the in-hull kit or the cable caked in the contents of your bilge. Just the usual respect for the new, that's all.

www.allgadgets.co.uk > marine instruments > nasa depth transducer


John

 

[quaelgeist2]

Have you set the sensitivity level coorectly ?
The Target allows to set a level below which it will check with increased sensitivity.
That means also below that level you get "double readings", meaning there are two layers reflecting differently (a bit like the seafarer did). It can be confusing and you can set this level lower to not have that in preferred shallow areas.
I personally found it easy to spot the -real- lower depths between the 'other' readings.
chris

 

[brian_neale]

Definitely will not work out of the water. You could always stick the transducer in a deep bucket!

My NASA Target used to get confused at regular intervals, usually by under-reading significantly. After a few seasons I was able to correlate these occasions with having crossed the track of something big, and the disturbed water was giving strong echoes. Apart from that, and getting rid of the bubbles in the oil, it worked well, reading to 50m or so out through Hurst Narrows even firing through a GRP hull. Might be worth checking the connector on the back of the sounder/end of transducer lead for corrosion - mine needed a clean and a smear of silicone grease from time to time.

 

[Aja]

Fitted a new Clipper depth for this season, with transducer mounted in hull. Have had no problems with it, and will read depth down to 1.4 metres which is the keel offset in my boat, measured I may add when puposely grounded. At the other extreme was out in Loch Fyne at the weekend and it measured to 100 metres then began reading about 5 metres. Not a problem as I wont hit anything in 100 metres depth.

I had to slow down the 'ping' rate on mine and increase the averaging rate to get a smooth reading as the transuder will send out 7 pulses every second which made looking at the readout tiring.

Very good and accurate piece of kit.

Donald

 

[tgalea]

Hi,

i'm still having problems with my seafarer mkII and understand the nasa transducers should work on my unit. Do you have any in-hull transducers for my model because my boat is now already in the water and would not like to have to wait until winter.

Thanks

Tyrone.

 

[Joe_Cole]

Thanks for all your feedback. I'll have another look this weekend.

Incidently, I phoned NASA and they suggested testing the Transducer with a multi meter. Apparently it should read 75ohms.

Regards

Joe Cole

 

[Avocet]

My Clipper depth sounder periodically gives wildly fluctuating readings. It doesn't double the depth or anything logical, just puts random (seemingly) numbers up for a few seconds and then sorts itself out. Sometimes the numbers are much more than the real depth and somtimes they're much less.

That said, I had an Autohelm St30 before that and it was also susceptible on occasions (and the display was forever misting up!) All in all I prefer the Clipper but would be curious to know how to solve the problem (if possible).

 

[yachtbits]

Probably not much help but...

If it keeps giving you loads of grief, maybe a change to a Silva Star depth system might be worth considering.

The transducers in these systems are the same as the ones used in their top of the range networked systems found on racing yachts. They are flush fitting, and extractable for cleaning. (can be "in-hull" mounted as well).

The Star range is actually a stripped down version of a much higher spec system. This is how they have achieved such a competetive pricing structure, but the basics of the systems are still the high quality of the high spec systems.

Oh, by the way, We've just been given Approved Dealer status by Silva and they are available on-line at...


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