Dual transducer to one fish finder help

[Coho975]

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.