Dual transducer to one fish finder help

[Jonesy84404]

To answer your first question, no.  Are you powering your graph from the TM batteries?  Your Ulterra transducer is powered from a graph, not the motor, it can't be operating if it's unplugged.  Sounds more like electrical noise to me.  If your Ulterra has the US2 transducer, the 2D only round puck, it will plug into a Helix unit, HumminBird makes an adapter for it. They also make adapters for Lowrance and Garmin. Unless you're partial to Birds, you don't have to go that route. It will work on another Hook, or most others from the "big 3". The Hook units are designed as stand alone units and can't be networked. If your Ulterra has a different transducer than the US2, you will have to be more selective of your second graph to to utilize the SI and DI.

You may be right on the electrical noise. Is there a way of eliminating the electrical noise?

It sounds like you are picking up interference from your trolling motor, does the electrical noise go away when the trolling motor is up?

If the trolling motor is down and in use, but not plugged into the back of the
fish finder I loose my depth numbers and other items off the screen. But if I unplug the back transducer and plug the minnkota in it reads just fine.