Furuno 587 and Airmar TM260 configuration problems

[mazzuca]

Hi Gents,
I really need some expert help to set or rearrange my Furuno FCV 587 and Airmar TM260 kit. I have a 20ft ship, Yamaha 115HP, always fish in saltwater, between Rio de Janeiro islands and from 2 to 60 meters depth. I will list the problems bellow, the most important first and will include some pictures to illustrate some of them:

1) Mostly always lose the signal in shallow water (2 meters or so), near the rocks where I fish;
2) Many times lose the signal when the ship is note moving (stopped);
3) There is always an image noise in the upper side of the screen (see picture);
4) It usually lose the signal at more than 12 nautical miles/h;
5) Also TM260 produces a continuous sound noise, like “click, click, click, click”, at regular intervals, that I suppose it is normal (sonar sending signals?), but would like to be sure of that;

I usually use bottom discrimination and accurate fish set to on, but even putting them off, it happens the same problems.






Please, any help to improve my kit?

Thank you, Daniel

 

[mazzuca]

 

[mazzuca]

 

[mazzuca]

 

[Snips]

Mazzuca,
Thank you for your pictures. It is not uncommon to hear a transducer clicking while the sounder is transmitting. In looking at your pictures you are experiencing the classic signs of turbulence, note the many gaps in the bottom on the 50Khz side while the 200Khz has one or two. Also I can imagine that as the vessel speed increases, the sounders performance decreases. It may be the angle of your pictures but the inboard part of the transducer looks to be higher than the bottom of the transom. If it is, I would first suggest lowering the transducer like the mounting instructions to see how much performance you can gain. If it were my boat, as long as it didn't interfere with the performance of the outboard I would look at getting the transducer as close to that centerline drain plug as possible.

Snips

 

[mazzuca]

Snip,

Thank you for sharing your expertise (with all of us).

Lowering the transducer will result in new holes in the boat, because it is already lowered at the maximum possible. Locating the transducer close to the centerline will also result in new holes. No problem, I can do new holes in the boat. What I want is your expertise so you can help me place in in the best location.

As far as the centerline, I placed the transducer following the 15cm recommendations that says, "keep in mind that itshould be a minimum of 15 cm (6") beyond the swing radius of the propeller, so the water passing over the transducer does not cause a flow disturbance to the propeller". I can locate it near the drain plug without problems, but I think I would not be respecting this 15cm rule. No problems with that?

What I would do is take today more pictures of the actual installation, showing the propeler so you can help me and suggest where you think would be the proper place for the new location.

Thank you again, Daniel

 

[mazzuca]

 

[mazzuca]

 

[mazzuca]

 

[Snips]

Mazzuca,
Thanks for the additional pictures. The goal for attaining good sounder performance is getting the face of the transducer below the turbulence layer that the hull creates. Shallow draft and shallow dead rise hulls present the greatest challenge specially with transom mounted transducers. Your strake just to the starboard outboard also isn't helping. If going closer to the centerline drain plug is going to cause problems for the engine then that is not an option. In the past I seen a few vessels that have benefitted from using this adjustable transducer mount that Airmar made. Most don't use it the way it was designed which was totally getting the transducer up out of harms way when running. The way I have seen that it works very nicely is when the deployed (lowered) position the transducer is 4-6" below the bottom of the transom. In the up position it is the same depth as a normal transducer would be, about an 1/8" below the hull. As you can see from the photo it has quite a few adjust holes for the position pins. One note, this mount was designed for the B-258 not your B-260, however I don't think it would take much to make it work with the B-260. Just a thought for you to consider.

Snips

 

[mazzuca]

Snips,

can you tell me where I can buy one of this via internet in US?

Is it appropriate for saltwater?

Daniel

 

[mazzuca]

Snips,

please note the following, look at the image taken today. The vesel was not moving at all, the Yamaha was completely turned off, and the sea was extremedly calm. Even though the Foruno still shows a litle noise at the top, but there was not turbulence at all

 

[mazzuca]

Snips,

follows another image of today. The Vessel was tied to the deck and all turned off, except foruno (of course vessel was not moving). Note the noise at the top of the screen. There was 1.61 meters depth

 

[Snips]

Mazzuca,
If you are trying to get the top section of the display perfectly clean you may not be able to. It is pretty normal to have some of shallow water targets. But maybe you are asking about the line at 1.61m and then the gap to the surface. The 587 has a function calling Zero Line Rejection which is in the calibration menu. You can turn it on or off and set the depth to how deep it work to. The sounder is preset to have it on and the depth is set to 4.5ft or about 1.6m.

Snips

 

[mazzuca]

Hi Snip,

Thank you again for your answer.

Yes, I was talking about the noise at the top of the screen, but if it is normal, it is OK.

The line at the 1.61 meters is the space where bottom disc will show the bottom images

I didnt understand the meaning of Zero Line Rejection, I will test changing this value to see what happens.

Still have the problem of losing the signal when the vessel is not moving, in shallow water or at more than 12 nautical miles. For that, I was trying to buy the adjustable transducer mount, but couldnt find it. Can you tell me where I can buy one of this via internet in US? Is it appropriate for saltwater?

Thank you again, Daniel

 

[Snips]

Mazzuca,
It doesn't take much turbulence to affect the sounders performance. Try this test when you have a chance. While at the dock take a paddle or oar and swipe it by the transducer to see what happens.

Snips

 

[mazzuca]

Hi Snips

I made this temporary transducer adjustable bracket (made of marine wood) to test the set and find a good position of the transducer without having to make new holes.





I already tested it yesterday in almost the same position where it was fixed in the transom, of course, with same comparable results.

Do you think I should test it all the way down (almost 20cm) to get some improvements?

Thank you Daniel

 

[Snips]

Mazzuca,
It's a battle and very frustrating trying to find "the right spot" for transom transducers. Normally lower is better. Below are a couple of ideas how others ended up dealing with the turbulence issue.

Snips

 

[mazzuca]

Good pictures Snips

Thank you. Are they all using the same or comparable transducer? Do you have more pictures or Links of those solutions?
Daniel

 

[Snips]

Mazzuca,
Both of those were 1kw transducers, one a B-260 (same as the TM-260) and the other was a CA50/200-1T. I have also seen some very nice adjustable mounts as pictured below. This gentlemen had a buddy that had a machine shop who crafted this bracket for him. It helped but in the end he ended up removing it and replacing it using a thru hull transducer with a high speed fairing.

Snips