DFF3D always showing a lot of fish in the middle of the screen

[kjohn911]

Has anybody experienced and issue where the DFF3D in history mode and Cross section shows a lot of fish ( I think it's interference) down the middle of screen? Is it a setting I'm missing or faulty equipment.

 

[Ackbar]

Typically when you see a lot of interference down the center it is a grounding issue, make sure that the transducer cable is grounded correctly, the conductive tape needs to be under the clamp

 

[kjohn911]

I will redo the grounding and post my results this weekend. Thanks!

 

[Quitsa]

Has anybody experienced and issue where the DFF3D in history mode and Cross section shows a lot of fish ( I think it's interference) down the middle of screen? Is it a setting I'm missing or faulty equipment.

It may be interference as noted. However, I have seen this routinely when there is seaweed or a big school of small baitfish under the boat. There is a "Fish Detection Level" setting in the multibeam sounder menu. Do you have it set to high? Try a lower setting if so and you should not see as many red dots for fish schools.

 

[kjohn911]

It may be interference as noted. However, I have seen this routinely when there is seaweed or a big school of small baitfish under the boat. There is a "Fish Detection Level" setting in the multibeam sounder menu. Do you have it set to high? Try a lower setting if so and you should not see as many red dots for fish schools.

Thanks, I've adjusted the fish detection levels. It does remove some dots, there are always way more dots in the middle, even when there's nothing under the boat.

 

[Quitsa]

Thanks, I've adjusted the fish detection levels. It does remove some dots, there are always way more dots in the middle, even when there's nothing under the boat.

Have you tried setting the gain manually and reducing it? Is it possible there is something on your hull in front of the DFF-3D transducer that is creating turbulence?

 

[kjohn911]

I redid the transducer grounding. Now it looks really good. Thanks!

 

[Cabo92]

I have the same problem I posted on here before except mine is a dark red cone down the middle I need to open the box up myself and look and the wiring. Was it fairly simple to correct ?

 

[kjohn911]

I had a very similar picture as you're getting. When looking at history mode, it would show a lot of dots down the middle constantly.

The process was really easy, make sure you have the manual to ensure the transducer is reconnected correctly. I had the conductive copper on it, but I had electric tape over it. I had also trimmed the conductive foil off the individual wires. The conductive copper needs to be in contact with the metal ground plate. I'm thinking that was my mistakes.

 

[Cabo92]

I had a very similar picture as you're getting. When looking at history mode, it would show a lot of dots down the middle constantly.

The process was really easy, make sure you have the manual to ensure the transducer is reconnected correctly. I had the conductive copper on it, but I had electric tape over it. I had also trimmed the conductive foil off the individual wires. The conductive copper needs to be in contact with the metal ground plate. I'm thinking that was my mistakes.

Ok good deal I'm sure that's my problem. My installer is a Garmin guy so really didn't know what was going on. I'll get to the boat this week and try to fix using those instructions

 

[Cabo92]

I just opened the dff box and there is no conductive copper tape around the shielding wires. I think this is my problem. What size conductive tape is best? Does it have to be double sided ? I took the clamp off to show only the shielding wires are around the main wire.

 

[kjohn911]

LOVIMAG Copper Tape (1/4inchX82.5FT), Copper Foil Tape for Stained Glass, Copper Tape Conductive Adhesive for Guitar and EMI Shielding, Soldering, Crafts, Electrical Repairs, Grounding, DIY(1Rolls): Amazon.com: Industrial & Scientific

LOVIMAG Copper Tape (1/4inchX82.5FT), Copper Foil Tape for Stained Glass, Copper Tape Conductive Adhesive for Guitar and EMI Shielding, Soldering, Crafts, Electrical Repairs, Grounding, DIY(1Rolls): Amazon.com: Industrial & Scientific

www.amazon.com

This is what I used.

 

[kjohn911]

I used 1" tape I found on Amazon. Seems to work pretty good.

LOVIMAG Copper Foil Tape (1inch X 66 FT) with Conductive Adhesive for Guitar and EMI Shielding, Crafts, Electrical Repairs, Grounding,Masking Tape.​