Help With Interference after Upgrading

[BassCatKWG]

Hello All, the purpose of this post is to gather some ideas and advice about what may be happening in my situation. For the last year I have had the following:

Helix 7 DI G2N (console) (DI transducer on transom) (AS GPS on stern)
Helix 9 Mega SI G2N (console) (Mega SI transducer on transom)
Helix 10 Mega SI G2n (bow) (Mega SI transducer on Ultrex) (AS GPS on bow)
Ultrex version of the 360
Ultrex 112lb 36 volt link
All hooked to ethernet switch

***With this set up I never noticed any interference no matter what transducer I had allocated to whatever unit.



Here is the problem:

I purchased a new Helix 12 G3N Mega+ SI and installed it yesterday. All I did was change the transducer to the new one from the Helix 9 on the transom, and placed the 12 head unit where the 9 was (had to change the mount obviously). Basically just swapped the new 12 in place of the 9.

Was out at the lake today and with all (3) graphs on the 360 was so "wagon wheeled" with interference that is was virtually unusable. If I shut off both graphs (the 12 and 7 at the console) it would get much better but still a little interference. After that I tried it with just the 7 on (bad interference) and was the same with just the 12 on (bad interference). I also had some bad interference on the 12 when using side imaging and the Pro XS250 running, kind of a random strafing effect that was a different color and would come and go. All the electronics are fed from my cranking battery and the Ultrex is on a dedicated 3 bank.

Seems really weird that by just swapping the one graph out all these problems arise. Is it possible that:

1. The ferrite ring on the power cord for the gen3 is different (currently using the one from the 9)?

2. Something is internally wrong with the new 12 or new mega+ transcducer?

3. Something in a setting (noise filter)?

4. The (3) transducers I am using don't wanna play nice together (lol)?


Anyway, sorry for the long post but I really need some ideas on what to try. I will check the ground fuse in the ultrex tomorrow but I doubt its blown.

Any and all ideas, comments, tricks, solutions, etc. will be much appreciated!

[squib]

Where are you getting your power for the units? Direct to the battery or catching power under the dash or at the bow?

[BassCatKWG]

Thanks Squib. I have dedicated #8 marine cable running straight from the battery, fused, and then to the graphs. One set to the bow, another to the console. I don't think its a voltage drop, I have monitored with a multi-meter and never seen it under 12 volts.