400: Transducer placement?

[tuskie]

Have added a sonar module to the Raymarine network on our L400 so we can find fish as well as get a better guide to the bottom type when time to anchor.

All goes well until we try to find a suitable place for the Airmar P79 "in hull" transducer. Not wishing to cut any more holes in the hull and being impatient to fish rather than haul out to fit a " through hull" bronze transducer, I thought the in hull 'ducer would do the trick. Especially as the hull bottom is solid fibreglass rather than the cored laminate that these transducer can't tolerate.

No luck! Just a gobbledygook read out. Tried the suggested trial using a plastic bag containing transducer and water in several hull places. I even tried to mount the wet box in a likely spot 2 feet forward of the keel, but no useful readout. Hang the transducer out the back and the read out is perfect. Not sure why. Perhaps the laminate is not composed of uniform materials. Maybe it has air in the layup ( god forbid!) or some other technical issue that I'm ignorant of.

Anyone been here and done that? Otherwise it's a new through hull transducer, a haul out and a hole saw. Cheers!

[arsenelupiga]

1. i would put more thought to elegant on demand installation. As you say works fine just submerged.


2. Alternative, I would recycle speedo thruhull.



new thru hull brings bad dreams.

[gspeak]

We added the same transducer to our L380 for the same reasons. I'm assuming that you are plugging the transducer directly into a MFD that is on the Raymarine network.

I "stuck" the transducer in the same port forward location in front of the keel, as the existing tri data transducers (depth/temp & speed). It is forward & a bit outboard of the old depth transducer (which is still working), only max 300mm away but both work fine.

The picture on our a77 MFD is brilliant & certainly eases my mind a bit when anchoring around reefs etc.

Dave


Sent from my iPhone using Cruisers Sailing Forum

[tuskie]

Originally Posted by gspeak

We added the same transducer to our L380 for the same reasons. I'm assuming that you are plugging the transducer directly into a MFD that is on the Raymarine network.

I "stuck" the transducer in the same port forward location in front of the keel, as the existing tri data transducers (depth/temp & speed). It is forward & a bit outboard of the old depth transducer (which is still working), only max 300mm away but both work fine.

The picture on our a77 MFD is brilliant & certainly eases my mind a bit when anchoring around reefs etc.

Dave

Thanks Dave. I sealed in the wet box in the opposite hull to the tri data transducer to avoid interference at 200 MHz but this location did not work. I've since realised that the frequency is slightly adjustable so interference close to the other transducer, as you suggest, should not be a problem. I tried the location you used, next to the existing tri data using a plastic bag "wet box" but it did not give a good reading. I may retry using the proper sealed wet box in this location.

I like Arsenalupiga's suggestion of recycling the existing hole of the tri data. I only really use the depth readout this provides, and wonder whether the Raymarine ST60 data gauges could access depth information from the sonar module? Might ask Ray himself about that one.
Cheers

[Cheechako]

I have used clear epoxy inside the hull, as well as silicone for fish finder transpnders. You need to ensure no bubbles though.
I gave up on oil filled things long back... seem to always leak or be a problem...

[Emmalina]

Originally Posted by Cheechako

I have used clear epoxy inside the hull, as well as silicone for fish finder transpnders. You need to ensure no bubbles though.
I gave up on oil filled things long back... seem to always leak or be a problem...

+1 on the leaky oil replacements..
Don't you mean 200Khz for your transducer !

[tuskie]

Originally Posted by Emmalina

+1 on the leaky oil replacements..
Don't you mean 200Khz for your transducer !

Yes, sorry, it's killer hurts! The mega hurts is in the radio. You can tell that electronics makes my brain hertz. ( Bhz)

The Raymarine in hull transducer sits in a silicone sealed wet box filled with water or ethylene glycol. It's less drama than oil. In any case, a leaky wet box wasn't the problem.

Thanks Cheechako. I'm glad I didn't epoxy it in position before I found it didn't transmit a good echo.