Downrigger cable hum affects fish finder

[whoswho]

I just installed a gas trolling motor, and downriggers on my boat and took 'em out for the first time yesterday. For some reason the cable hum screws with my fish finder. It won't update depth and is locked on 2.1 feet even though I am in 120 feet of water. The transducer frequency is 200KHz. In an attempt to isolate the problem I raised the downriggers up and after a bit of time the fish finder worked like normal. The trolling motor does not affect it after testing that too. How do I fix this or has anyone had this problem before?

 

[Thalasso]

Re: Downrigger cable hum affects fish finder

If your downrigger lines are humming you are trolling at the right speed. Maybe a through hull transducer, that way it will be away from the line. I had a transom transducer on my boat with down riggers fishing for waleye and never had that problem.