Depth finder interference

[lefty]

I have 2 depth finders. One up front and one in the rear. I'm getting a little feedback from the rear one on the front screen. I've adjusted the noise setting as high as it goes still no help. Does anyone know what causes this? When I cut the rear one off it goes away. Its mostly on the sonar screen but shows a little on the side/down imaging too.

Both graphs are hooked to the same power source. Separately fused, inline.

 

[spagatti]

I don't know the cause, but I believe the pros put the rear in Stand by mode when the go to the bow.
Probably very similar to trolling motors causing interference when hooked to the same battery as the fish finder.

 

[lefty]

I run a 1448 MV. The rear graph is for my partner.

 

[tomme boy]

Separate batteries works sometimes. Otherwise you might need to mix the brands if they are the same. Or run one in a different freq.