Aborted launch - new depth sounder not working

[James_Calvert]

Just been looking at an installation video.
The transducer is huge compared to the old seafarer unit isn't it!

Was there really no alternative (apart from a NASA unit using the old technology)?

Only trouble shooting thought I picked up from the video is that you might have got an air bubble in the bath, ie you didn't put enough antifreeze in it before popping in the transducer. But I expect you'd have avoided that one.

 

[ghostlymoron]

It's never going to work if directly above keel. Too much thickness.
I fitted my NASA one in a piece of plastic pipe with the bottom cut at an angle to make the pipe vertical.
Yours is probably an electrical problem (aren't they always?). Can you rig a temporary supply direct from battery?

 

[Stemar]

ISTM that the first thing to do is find out if the transponder works at all. Dangle it over the side and, if it doesn't give a sensible reading, either the transponder or the instrument - or both - is dead.

 

[eddystone]

Just been looking at an installation video.
The transducer is huge compared to the old seafarer unit isn't it!

Was there really no alternative (apart from a NASA unit using the old technology)?

Only trouble shooting thought I picked up from the video is that you might have got an air bubble in the bath, ie you didn't put enough antifreeze in it before popping in the transducer. But I expect you'd have avoided that one.

Seems to be only in-hull transducer compatible with i50. Reason I chose the Raymarine was a) matched existing log b) able to daisy chain off latter with spur cable - I'm total numpty when it comes to boat electrics so being able to avoid finding a new 12v connection was attractive.

 

[Refueler]

How is the transducer fitted? Mastic or in an oil bath? What do Raymarine recommend?
Why add to the thickness of hull by extra fairing? most through hull transducers come out the hull at an angle to the vertical & operate with the hull heeled . So, surely, it stands to reason it is not necessary to fair it in internally.
Are you happy that the transducer is receiving sufficient voltage to operate correctly? Just ticking may not mean that a signal is being properly transmitted- or does it?
Is the receiving monitor properly installed?

Exactly .. no need to create deadrise and increase thickness of hull to sound through.

Normal is to cut the in hull tube to face at an angle to compensate ... fill with fluid ... mount transducer so it sits with face at angle to the hull and is vertical to waterline ... its often wise to set the nut so transducer face doesn't quite touch hull ... just a fag paper off ...

 

[eddystone]

Exactly .. no need to create deadrise and increase thickness of hull to sound through.

Normal is to cut the in hull tube to face at an angle to compensate ... fill with fluid ... mount transducer so it sits with face at angle to the hull and is vertical to waterline ... its often wise to set the nut so transducer face doesn't quite touch hull ... just a fag paper off ...

This is not how Airmar transducer works. It can't be cut and has minimum deadrise angle (22 degrees) it can be placed at so have to build up inside of hull to bring angle within limits. Once fixed the transducer and locking ring can be adjusted so that top is level. Not easy getting this right because the ground where the boat is propped is not exactly level.

 

[eddystone]

And as far as I can seen it's the only transducer compatible with Raymarine i50

 

[Refueler]

This is not how Airmar transducer works. It can't be cut and has minimum deadrise angle (22 degrees) it can be placed at so have to build up inside of hull to bring angle within limits. Once fixed the transducer and locking ring can be adjusted so that top is level. Not easy getting this right because the ground where the boat is propped is not exactly level.

Just had a look at the 79 data ...... WOW !! My apologies.

 

[Jodel]

i50 manual section 10.2 p77 Tells you what the dashes mean. Check the transducer wiring to the back of the i50 as listed on p27.

 

[peekayDUDE]

Sadler 32 has a generous hull thickness I believe? The P79 can transmit healthily through 12-16mm thickness fibreglass. Anything thicker than this will struggle as signal from the P79 weakens off.

 

[eddystone]

i50 manual section 10.2 p77 Tells you what the dashes mean. Check the transducer wiring to the back of the i50 as listed on p27.

I hadn't seen that - I'm trying to get a marine electrics person to visit the boat to see if there is a wiring/connection issue as I don't have expertise or equipment to diagnose problem. If this ends up pointing to the transducer I can't make hull thinner; maybe I should remove the Raymarine and Airmar and fit a NASA Clipper unit with a less fussy transducer?

 

[peekayDUDE]

I hadn't seen that - I'm trying to get a marine electrics person to visit the boat to see if there is a wiring/connection issue as I don't have expertise or equipment to diagnose problem. If this ends up pointing to the transducer I can't make hull thinner; maybe I should remove the Raymarine and Airmar and fit a NASA Clipper unit with a less fussy transducer?

I have just read the entire thread. In the first post you mention you are back on dry land, therefore my question is did you have the P79 fitted on the water and the i50 had dashes or has this only been on dry land?

If you can hear the transducer pinging and it worked in the bucket of water - it sounds like it is functioning.

I doubt very much an inhull transducer would get any reflections on dry land through the hull, sometimes thru-hull transducers pick up the odd reflection when they are on a dry dock.

AIRMAR state the P79 is for 12 - 16mm thickness, not familiar with Sadler 32 hull. What filler did you use to thicken the hull and how much has the thickness increased by? Any chance of pockets of air or bubbles in the filler? If the transducer is not picking up any sort of reflection the instrument will just flash.

Also worth checking the voltage into the instrument head, if the voltage is low it will not supply the transducer sufficiently. Either measure with a voltmeter or put it on a direct 12v supply, see if that boosts it.

 

[eddystone]

I have just read the entire thread. In the first post you mention you are back on dry land, therefore my question is did you have the P79 fitted on the water and the i50 had dashes or has this only been on dry land?

If you can hear the transducer pinging and it worked in the bucket of water - it sounds like it is functioning.

I doubt very much an inhull transducer would get any reflections on dry land through the hull, sometimes thru-hull transducers pick up the odd reflection when they are on a dry dock.

AIRMAR state the P79 is for 12 - 16mm thickness, not familiar with Sadler 32 hull. What filler did you use to thicken the hull and how much has the thickness increased by? Any chance of pockets of air or bubbles in the filler? If the transducer is not picking up any sort of reflection the instrument will just flash.

Also worth checking the voltage into the instrument head, if the voltage is low it will not supply the transducer sufficiently. Either measure with a voltmeter or put it on a direct 12v supply, see if that boosts it.

First of all all this has been on dry land as the boat has been out of the water since the end of October last year. I've had this i50 and the Airmar transducer for quite a long time and just got round to fitting it. I didn't see the reference to 12-16mm thickness anywhere in the literature - there is obviously no way of finding out the thickness of the hull. The Sadler 32 is a bit of a pain to fit transducers in as there is only one suitable location, underneath the bunks in the fore cabin. The aft of this space is built up to provide a level mounting for the through hull Airmar ST800 log transducer and the previous depth transducer was located dead on the centreline, over the keel but with the V of the hull its just too narrow for the "fat" Airmar P79; their recommendation is to fit to one side of keel anyway so I'm using the only space available. However as previously noted, the deadrise here is nearer 30 degrees so there is no alternative to add some material to reduce that. I may have added 2-4mm most at the bottom, nothing at the top so we have sandwich of original layup and "flowcoat"/some marine epoxy/body filler but with a lot of sanding between layers. I have been quite careful not to get any voids but I suppose the boundary between materials may have an effect.

What I need to do is to get marine electrics specialist to eliminate wiring/contacts as a cause before assuming the transducer itself is the problem.

This is all so frustrating - I really need to get this boat launched so at least I can do some autumn/winter sailing. Also my anti-foul, applied at the end of July will be time expired soon.