I just put a Lowrance 520c on the bow and on the console.  I have them networked.  I had them on the water together for the first time today.  The console unit loses the bottom at 30-35 mph.  It is connected to the same transducer that I had on an LMS 480.  Nothing about the transducer has been changed.

Do you think this new unit is more powerful and causing the transducer problems?  Do you think lowering the sensitivity would help?

Actually the Lms-480 has higher power than the Lms-520 and both units use the same transducer.  The sensitivity shouldn't make any difference, but you can try it.  Make sure the ping speed is turned up.

I am running the ping at 100% when I am under power.  I have only had it on the water once and next time out I plan to try a bunch of stuff even changing the heads to see if I can correct this problem.  I am grabbing at straws to come up with a cure.