Depth sounder problem

[mbird]

Recently, my depth sounder has been somewhat erratic with it's readings, and sometimes decides to flash, which the manuals tell me is a lost signal.

The sounder is an Autohelm SeaTalk, and is probably about 15 years old installed on the boat from new. I have had the display unit rigged up to a transducer in a workshop, which was suspended in a tube of water about 4 ft long, and the reading was correct and steady.

Next, the test transducer from the workshop was taken to the boat and suspended in the water over the side. The display ranged from 6 feet to 33 feet deep (in 6 feet of water) without the transducer being moved.

The problem seems to be no signal from the transducer installed in the boat, but I am also not sure if the display unit is giving the right reading even when there is a signal provided.

Anyone had similar problems?

 

[hlb]

It's quite common for depth sounders to give poor or bad readings. It's usually to do with the bottom.

Best solution I found was to have both depth sounder and fish finder. One or the other would mostly work at different depths.

 

[mbird]

Thanks Haydn, that's a good idea!

I have consigned myself to having a lift out now, so I think I'll change the transducer while she's out, as that's the cheapest part to check first!

 

[omega2]

Thanks Haydn, that's a good idea!

I have consigned myself to having a lift out now, so I think I'll change the transducer while she's out, as that's the cheapest part to check first!

probably marine growth on the transducer?? or if shooting through the hull just general growth. Or if it's an airmar sitting in a well inboard check there is fluid in it. most units read spasmodic in shallow water, ours reads through the depth of mud.

 

[mbird]

probably marine growth on the transducer?? or if shooting through the hull just general growth. Or if it's an airmar sitting in a well inboard check there is fluid in it. most units read spasmodic in shallow water, ours reads through the depth of mud.

Yes, it is an airmar, fixed through the hull about 18" from the centre line of a planing hull. I suppose it could just be down to growth, so a trip out is proabble needed to see if that's all it is.

 

[DAKA]

Anyone had similar problems?

About 7 years ago MBM featured a report on Echo Pilot experimenting with different substances to enhance their depth sounder transducers, KY Jelly came out favorite.
At the time we were experiencing reliability problems with our echo sounder in the murky waters of the River Humber and reliable soundings were unobtainable above 17 knots.

After reading the MBM article you can imagine my excitement regarding the reported qualities of KY Jelly. (If you don’t know what that is you best ask your SWMBO).
I immediately dispatched SWMBO to the chemist and that week end I withdrew the transducer and removed all the oil from the sounder tube using an old hand soap pump.
Then I took the tube of KY Jelly squeezed out the contents and went for it.

I can indeed confirm I went deeper and faster than I had ever managed before.

The problem was it is a water based substance and with winter freezing temperatures on the way I had no way of knowing when it would go hard.

If anyone cares to try it I confirm it will enhance your tackle and with the aid of a hand pump the whole messy job can be completed in a couple of minutes.

 

[AdeOlly]

Then I took the tube of KY Jelly squeezed out the contents and went for it.

I can indeed confirm I went deeper and faster than I had ever managed before.

The problem was it is a water based substance and with winter freezing temperatures on the way I had no way of knowing when it would go hard.

If anyone cares to try it I confirm it will enhance your tackle and with the aid of a hand pump the whole messy job can be completed in a couple of minutes.

Sounds like you're writing the script for 'Carry on down the Hamble'

 

[Searush]

Before you go to all that cost & palaver, try wiggling the cable at the back of the unit & at the transducer & see what happens. ANY moisture around the cable (copper) and its connector (often Alloy) creates a wonderful electrolytic battery. Green & white powder is a clear sign of problems.

Cut back to clean cable & remake the joints & coat with vaseline or similar. If it don't make it better, it won't make it worse & it costs nowt (well, maybe a new connector & a few pence worth of silicone grease or similar).

 

[mbird]

With all this talk of KY and vaseline, this thread has definitely turned a bit Finbar Saunders, phnarr phnarr

I have already checked the wiring at the display end which seems okay. Unfortunatley the transducer is a fixed one so I can't withdraw it, so it looks like I'll probably be replacing it with a retractable ST60 version when I can get the boat out.

 

[ian38_39]

A friend has one of these suspended types and often complains that his oil has gone. this may sound a bit strange but he was contemplating setting it in Jelly, think he was going to get gelatine crystals rather than a Robinson's Strawberry one but has anyone tried this?

 

[mbird]

By trial and error, the problem has now been traced back to a dodgy display unit, and not the transducer after all. It would be the dearest bit!

 

[stelican]

About 7 years ago MBM featured a report on Echo Pilot experimenting with different substances to enhance their depth sounder transducers, KY Jelly came out favorite.
At the time we were experiencing reliability problems with our echo sounder in the murky waters of the River Humber and reliable soundings were unobtainable above 17 knots.

After reading the MBM article you can imagine my excitement regarding the reported qualities of KY Jelly. (If you don’t know what that is you best ask your SWMBO).
I immediately dispatched SWMBO to the chemist and that week end I withdrew the transducer and removed all the oil from the sounder tube using an old hand soap pump.
Then I took the tube of KY Jelly squeezed out the contents and went for it.

I can indeed confirm I went deeper and faster than I had ever managed before.

The problem was it is a water based substance and with winter freezing temperatures on the way I had no way of knowing when it would go hard.

If anyone cares to try it I confirm it will enhance your tackle and with the aid of a hand pump the whole messy job can be completed in a couple of minutes.

KY jelly no good for through the bottom fixings!