hello a friend of mine up graded to a bigger unit andi bought his hummingbird 597 hd di unit and mounted the trancducer on my i pilot when i turn on the trolling motor the depth goes crazy and the screen looks bad. i have a 1197 on my boat as my mane unit. thought this would be a good unit for my troller. i have not went to the water yet but just playing with it on the trailor i dont believie its going to work. and it has the latest up grades done. it worked fine on his boat but trancducer was mounted on boat. ive read some stuff on rf interference. just dont know what to try first. thanks for all your help