Noise on DFF3D

[Bayhouse]

See attached pic, any suggestions for setting tweak's to clean up the return?

 

[brinkis]

You should start with auto fishing mode and see if you have noise.
Then you can set manually the gain, clutter, TVG and interference rejection etc…
Does not look to be noisy though.

 

[mattology]

are any other sounders running ?

 

[Quitsa]

The small vertical lines look just like the interference I see on both my DFF-3D and the HF CHIRP displays. Try setting the interference filter in the DFF-3D settings to "High". It should disappear. No other setting will fix it, not low, medium, or auto.

The 165Hz frequency of the DFF-3D is within he high frequency CHIRP band.

 

[Bayhouse]

are any other sounders running ?

I'll have to answer your question with a question. There is another xducer (B275) using the TZT19F sounder that was powered on but not actively displayed on the other MFD - does the xducer ping away all the time or only when displayed?

I have toyed with this, but not very methodically, at the dock and turned turned the other sounder off - I don't recall much of a difference.

 

[Bayhouse]

Brinkis / Quitsa - thanks for the suggestions, will give them a try next time out.

 

[gtstang462002]

are any other sounders running ?

I'll have to answer your question with a question. There is another xducer (B275) using the TZT19F sounder that was powered on but not actively displayed on the other MFD - does the xducer ping away all the time or only when displayed?

I have toyed with this, but not very methodically, at the dock and turned turned the other sounder off - I don't recall much of a difference.

If the sounder is powered on, it is running all the time regardless of if it is displayed or not. That way when you pull it up, you have a true historical picture when you do display it. I agree with Quitsa, set the interference rejection to high and it should go away.

 

[jp498]

For 14' of water, that's not bad.. It looks like noise, but could also be bubbles or junk in the water. I'd shut off other electronics till it cleared up and then you know where it's from if it's from your boat at all. Could be someone else's DFF3D if it's a busy harbor.

Also be sure the ground lug is connected on the DFF3D blackbox chassis and that the shield on the transducer cable is grounded via the clamps inside the chassis. Lack of good grounding here will cause noise in deeper water when signals are weaker.

 

[Bayhouse]

The small vertical lines look just like the interference I see on both my DFF-3D and the HF CHIRP displays. Try setting the interference filter in the DFF-3D settings to "High". It should disappear. No other setting will fix it, not low, medium, or auto.

The 165Hz frequency of the DFF-3D is within he high frequency CHIRP band.

Setting the interference filter to High worked for me. I had it set on Auto hoping it would figure out on its own but that didn't work.

 

[Quitsa]

What I find puzzling is that if you set up a frequency preset on the internal TZT 3 sounder to use CW 200 or 210Hz, it still interferes with the DFF-3D and vice versa and requires use of the high setting for the filter on both sounders.

Maybe one of the Furuno guys can explain why that would happen since in concept there is no longer overlap of the TZT 3 is using 200Hz and the DFF-3D is using 165Hz.

 

[Deep Blue]

Bayhouse,

What you are seeing is indeed sounder interference into the TZT3 probably from the DFF3D. It's not a lot of it, but it's there.

You can try to set the Interference Rejection to HIGH, and maybe slow the TX Rate of the TZT3

You also may also need to add a 001-605-510-00 TZT3/DFF3D Key Pulsing Connection Kit to prevent any frequencies from both the TZT3 Internal Sounder and the DFF3D from stepping on one another.

- Deep Blue