Jumpy Bottom Zoom

[Quitsa]

When I use the bottom zoom display on my TZT 3 16 using the internal HF sounder, the zoomed side of the display will jump up and down every few seconds. This only happens if the DFF-3D is also transmitting. When the DFF-3D is in standby, the zoom display is completely steady (I have an SCX-20 and heaving control is enabled). In regular single frequency mode, the display is steady with the DFF-3D transmitting. The jumpiness only happens in bottom zoom mode.

Is there something I can do in the settings of either the TZT 3 sounder or the DFF-3D that would make this stop? I tried using the preset custom frequency function to operate the TZT 3 sounder at 210Hz CW to avoid the 165Hz transmission of the DFF-3D but it didn't help.

 

[Deep Blue]

Quitsa,

Thanks again for the your post. Would it be possible to provide more information on what are the transducers that you are currently using..? Are you using any "Combo Transducer", or are you using separate individual transducers for both the DFF3D and the TZT3..?

You certainly have the set-up that I recommend (TZT3,DFF3D, SCX20). However, I've not seen this particular issue that you have described before.

- Deep Blue :think

 

[Quitsa]

I have a B175H driven by one of my TZT 3 16s and a 165T-B54 used with the DFF-3D. I also have a B175L connected to a second TZT3 (installation was done before you sorted out the Y cable).

It only seems to happen if the boat is moving. I was out yesterday and tried at the dock and the bottom zoom was stable. Once I was out fishing, it started bouncing again. It doesn’t seem related to speed as it happened both drifting and running at both slow 6 kts and high 30 kt speeds. The bouncing stops when I turn off transmission on the DFF-3D. I forgot to try one more thing which was to turn off heaving compensation to see if that was somehow a factor.

This is actually a pretty serious issue for me when bottom fishing. I like to use the multibeam sounder to show structure and the bottom zoom on the HF to see detail under the boat. Species such as cod hold very tight to small areas and the bottom zoom really helps to see them. Thanks