Recently replaced old Furuno LS series with FCV628 connected to original P319. Was hoping for easy fix as this is a secondary stand alone backup unit. FCV628 fit the existing dash space. Perf is better but readings drops out when up on step at normal cruising speed 22 knots. Always drops out at 30+. I know aluminum and bronze don’t mix. What about with a block? Can I upgrade to a bronze or SS 1kw thru hull transducer with a high speed block with this set up to hold the depth readings at higher speed? Boat is a Titan 249XL Cabin model aluminum hull with twin Yamaha 200s. Any recommendation would be appreciated. Tks.