problems with 587 and tm260



Having a few dramas with my sounder in deep water and wondering if anyone has experienced the same thing.

This will be a bit long winded but I'll explain everything.

I have a furuno 587 with a 1kw airmar tm260 transducer
And a lowrance hds7 with the standard transducer.

In shallow water, and when underway my 587 holds bottom fine,
But as soon as we stop in deep water, the 587 looses bottom, becomes very patchy and won't mark any fish or bait,

So it won't hold bottom or mark Bait when drifting,

Originally the tm260 was on the wrong angle, ( fitted by dealer!! ) so we removed it, and replaced it within the airmar specs, tested it again, same problem,

A few calls to furuno, a few settings changed, re tested and the same problem.

Furuno then sent me out a p66 to test, we fitted the p66 and headed back out the shelf, same problem

So a call to Barcrusher and where my tm260 is positioned is where they mount there's, but I'm using different trim tabs. They said they have mounted hundreds and never had this problem.

Also my lowrance transducer is in the same spot on the opposite side and does not have this problem!! The lowrance hammers as you will see in the pics it works great!!
Both sounders are run on full manual and all transducers are linked to the sounders correctly

I now have both transducers removed and they have asked me to drive back out the shelf, and hold the transducer over the side of the boat - taking away any possible interference from the engine/ trim tabs ect.

I've tried turning the motor off, turning the other sounder off ect ect

Has anyone ever seen anything like this before?? Or have any idea what could be causing this to happen?

The furuno techie said it's very uncommon to loose picture when drifiting, but I can travel in 1.5m sea at 20 knots and not loose bottom.

Cheers Matt.
Do you have any screen shots you can post? Also what is "deep water".

Thanks for the reply.

Well I've had a huge breakthrough yesterday.

Went out and tested both transducers yesterday and were pretty sure we have worked it out. Held them over the side and there was a huge difference with the p66 out performing the 1kw in a huge way!! - so the 1kw doesn't appear to be working like it should.

The second problem we think, is my trim tabs, ( Bennett m120 ) they are comin out of the water when there is even a little swell, were pretty sure they are what's causing it to drop out as the p66 held over the side had a great picture,

So great news pretty sure were getting on top of it.

For some reason the lowrance transducer on the port side doesn't drop out, so from here were going to fit the p66 where the lowrance transducer is and see what happenes.

Than when the 1kw is repaired Ill look into some kind of bracket to sit the transducer lower in the water.

It's hard to pinpoint the exact depth it would drop out as I don't stop anywhere on the way out and have never stopped to test, but where we fish in 80 fathoms it drops out.

Ill put some pics of the 587 up later, Very Happy were getting there.

Thanks Matt
Hi I am running the 587 with tm260 and ive played with the setting many times to try get better depth my sounder cuts out and you can't read the bottom after 250 mtrs which is no good as I fish 5 to 600 mtrs on the shelf I have ajusted the transducer and gone through everything I can think of any one had this problem and found a solution? Cheers Jamie :sorry
no haven't taken any shots and I fish between 300 and 600 mtrs
If you are able to post some screen shots I might be able to offer some suggestions.