analog depth sounder

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ErikKiekens

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I am so fed up with digital stuff not working and nobody can explain why, and fmea and rtfm and sea talk etc. Even the engineer who claims he can fix my depth sounder: all he can do is replace the display; if it works then it was the display. That will cost 500 euros without manhours. Mind you, if that was certain to solve the problem then I would have ordered that 2 years ago!
What was wrong with analog depth sounders??? I have never experienced any problem with them, and they gave additional information about the seabed. If I said I wanted an analog depth sounder today, am I crazy? No, don't answer that one. But is it a good idea?
Erik. Desperate.
 
Well, I wouldn't want a spinny one, but NASA do sell them if that's what you want:



Why would you pay someone just to change out an instrument head? It's two screws and a plug!

Pete
 
ErikKiekens said:
I am so fed up with digital stuff not working and nobody can explain why, and fmea and rtfm and sea talk etc. Even the engineer who claims he can fix my depth sounder: all he can do is replace the display; if it works then it was the display. That will cost 500 euros without manhours. Mind you, if that was certain to solve the problem then I would have ordered that 2 years ago!
What was wrong with analog depth sounders??? I have never experienced any problem with them, and they gave additional information about the seabed. If I said I wanted an analog depth sounder today, am I crazy? No, don't answer that one. But is it a good idea?
Erik. Desperate.
Click to expand...

What is it you have? And what's the problem with it?
 
prv said:
Well, I wouldn't want a spinny one, but NASA do sell them if that's what you want:



Why would you pay someone just to change out an instrument head? It's two screws and a plug!

Pete
Click to expand...

Taringa has one of these. I was initially sceptical, but it's never failed me. Even when there's been a lot of fouling building up, it might give stupid readings for a while, but it soon clears. I suspect it's emitting gamma rays and cooking the slime. And it looks fantastic!
 
elton said:
Taringa has one of these. I was initially sceptical, but it's never failed me.
Click to expand...

Well, the VDO digital sounder on Kindred Spirit never failed me either, nor the Raymarine one on Ariam :p

They're pretty reliable beasts really, especially compared to paddle-wheel logs and wind-sensors.

Pete
 
ErikKiekens said:
Raymarine ST50 tridata. Works fine except in shallow waters when it becomes interesting. Then reading disappears or becomes overly optimistic. I noticed sound is irregular.
Click to expand...

When you say the sounds is irregular, do you mean the signal it produces at the ultrasound frequency it works at?

I've just had a quick glance at the manual and it gives a minimum depth measurement of 0.8m and it doesn't work at shallower depths. I'm guessing that is down to the pulse length. Speed of sound in water is roughly 1,500m/s and varies a bit with salinity and temperature, so for a 1ms pulse there'd be an echo received before the pulse had finished transmission in shallower water than 0.8m below the transducer.

How erratic is the overly optimistic depth? I guess you've considered the obvious of using a leadline to calibrate it and set the offset. Forgive me if I'm teaching you to suck eggs.

Has the engineer said why he thinks changing the display will make a difference. From the symptoms you've described it wouldn't be the first place I'd look for the fault.
 
The shallow water is less than 5 meters. My keel is 2.35 meters. The overly optimistic depth would be like 30 meters (when in harbour, knowing it can't be any more than 3 or so)
The ping is irregular, I can hear it when listening to Radio 4. I listen to R4 for the weather forecast, and have always, over the last 30 years, on all different boats, heard the depth sounder. I imagine the stuff can't work properly with irregular ping. Is the ping generated by the transducer or the display? The engineer will change the display because he has no clue. I think.
 
ErikKiekens said:
The shallow water is less than 5 meters. My keel is 2.35 meters. The overly optimistic depth would be like 30 meters (when in harbour, knowing it can't be any more than 3 or so)
The ping is irregular, I can hear it when listening to Radio 4. I listen to R4 for the weather forecast, and have always, over the last 30 years, on all different boats, heard the depth sounder. I imagine the stuff can't work properly with irregular ping. Is the ping generated by the transducer or the display? The engineer will change the display because he has no clue. I think.
Click to expand...

I think this is your problem! If the 'ping' is audible the radio then there's some sort of interference/leakage taking place. I had ST50 on my old boat and never heard a ping on any radio or elsewhere. I'm no expert but would suspect a ground or whiled fault in the wiring?
 
Hello.

This is my first post on this excellent site, and although my contribution to this old thread is very late (I've only just found it) I'd like to respond to an earlier comment left by another contributor.

On 07-02-16 Skyflier suggested that being able to hear an echo sounder's "ping" on a radio might indicate a fault with the echo sounder. In fact this is not so and I'll explain why. Most echo sounders transmit their "pings" in the Long Wave band: B&G equipment, for instance, transmits at 170 kHz, whilst the most common transducer frequency these days is 200 kHz.

This is very handy because a commonly used "quick and dirty" test to check if a sounder's transducer transmitter circuit is running, is to select the Long Wave band on a radio receiver and tune it to roughly the frequency of the echo sounder. It doesn't need to be exact, and for a 200 kHz transducer it will be somewhere near the centre of the L.W. frequency range on the radio's tuning dial. With the echo sounder running, and with the transducer within a metre or so of the radio, you should be able to hear a rapid "click - click - click" coming from the radio.

So... the clicking that Erikkiekens heard coming from his radio is perfectly normal. It is, moreover, a positive indication that his sounder is transmitting. Those audible clicks should, however, be regularly spaced and (as long as the echo sounder's settings are not altered) the clicks should not be intermittent / interrupted or vary in volume.

I hope the foregoing might be of some use!
 
Our club support boat (mobo) has had a Huminbird sounder chart plotter GPS etc fitted. It does give a pictorial presentation of what is on the bottom. However it does wipe out any real VHF reception when it is turned on. really annoying/dangerous.
Apparently the Huminbird is quite a high powered sounder. I have tried all the usual tricks of isolating supplies etc. The radiation seems to come from the display unit. Moving the VHF antenna away by a few meters seems to reduce the interference. Inquiries to Huminbird gtot no response at all. olewill
 
My digital depth sounder causes interference on Ch. 74. Only a problem when I was using the Crinan canal, but took an age to identify the cause. I can hear the ticks from the transducer if I put my ear near it.

Eons ago, my analogue depth sounder ( ye olde ring of fire] gave two echoes in shallow water (actual depth + times 2 as it bounced off the hull and the seabed again).

Didn't the thread just die because it was a rant?
 
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