Sounder not working picking up bottom.

[Redrocks]

Members,

I recently acquired a Raytheon L1250RC combo and installed it in my Signature. I purchased a transducer from a Raymarine dealer (Airmar P66) and a Raystar 125, installed them. The GPS works fine.

Trouble is, I have problems with getting a bottom picture. It is powered up and gives a signal like all is sweet, then cuts out when putting along (less than 3 or 4 knots) or you are hit with a big wave at anchor. After these hissy fits, it says I am in 1-2m of water, when I am actually in 50m. It doesn't correct itself when you stop moving like all my other ones have. I have to kill the power and start again.

The transducer is mounted very low in the water, probably too low, and angled down a bit as I couldn't get the correct angle with the wedge in and the weather was good on the weekend.

With the position of it in mind, I am wondering if it is getting interference from the deckwash pickup tube mounted beside it, pics attached.

Any help appreciated as I live 200km from the water and testing is difficult.

Cheers,

Redrocks

[GBC]

Is it just me or is the transducer not mounted vertical?

Could be part of the issue.

[peterbo3]

I had the P66 transducer on a Ray 760 which is the same unit with a smaller screen.
As GBC noted, the unit does not appear vertical. It has to be getting disturbed water from the pickup as well so that will cause a poor bottom read. The 2M depth readout seems to be common. Mine would also do that but I did not have to restart. The units seem to have sort of "memory" after use in rough water & take some time to settle down.
I removed the paddle wheel as well because it is not needed with the GPS providing SOG.
Rather than mount the transducer directly onto the hull, could I suggest fitting a poly or timber mounting block to the transom. That way, if you have to make adjustments to the transducer, you are not drilling holes into the hull FG.

[Redrocks]

Thanks Peter, handy info. I appreciate the fact that the pickup creates turbulence, but doesn't explain why it won't give me bottom at rest after restarting the system, or even "bobbing" around in the waves.The transducer is slightly out of vertical, it just looks worse because the pickup is inclined a bit also.

I will try the mount plate and see how it goes.

[GBC]

I've got a Raytheon too and it will happen intermittently depending on how its tuned. I just back the gain right of til it finds the bottom (abaout 2 secs) then crank it again.

[bigjimg]

Redrock look under the hull from inline with your transducer and up towards the front of the boat.Does the transducer line up with strake that stops half way approx.This could be having some affect on performance while at speed?As for performance while off the plane maybe try insulatung the transducer cable from other electrical interference or rerouting it away from all other cabling.My two bobs worth.In any case hope you get to the bottom of it.Jim

[Snapp]

Redrocks I have a P66 aswell & have had issues, but not as bad as you.
I put a slide on mine to stop drilling more f$#@$n holes.