Re: Interference on HDS8
Since the HDS unit doesn't have any problems by itself you need to look at the trolling motor as the cause. It's usually a ground problem inside the trolling motor. The ground wire that goes from the direction indicator light down to the brush plate is either loose at one end or the other or something like that. There have been instances like a flat spot on the brushes causing an arc that the ducer picks up or a bent armature that causes a slight vibration that the ducer is picking up. The trolling motor works fine but the HDS unit picks up the issue.
The HDS units have the broadband sonar built in and this is a more sensitive receiver in the transducer than what you were used to with the LMS 520 so that is why you are seeing the interference now.