G'day all - I have a Furuno GP-1850DF sounder plotter fitted to my boat, and recently purchased a Furuno FCV-587 fishfinder sounder as the screen on the dated GP-1850DF unit is quite small, my intention was to just use the GP-1850 in plotter mode and use the FCV-587 with superior screen size and resolution to find fish. I have just plugged the transducer cable from the 1850 in to the 587, but notice that occasionally there are some strange readings on the sounder screen, and speed seems to cause interference. My question is regarding the compatibility of the transducer between these two units, the transducer is a bronze thru-hull unit, not sure of any model identification but perhaps there's some knowledge out there re the transducers that would have commonly been fitted to Grady White boats (190 Escape) back then. The GP-1850DF is around 2000-2001 vintage, the FCV-587 is about 4 years old. I would prefer not to have to fit an additional transducer if possible. Over to you and thanks. :respect