My unit is a Humminbird 899, and I have a weird problem. I'm getting noise feedback, I have the correct transducer XTM 9 HDSI 180 T, I think that's in the correct order. Here is the strange part, I only get feedback in SI mode and only at certain speeds. I have a motorguide 36 volt, 108lbs thrust. Speeds 1-3 its so bad the whole screen is wiped out. 3.1-5 fine no feedback, 5.1-7 some feedback, on high none. It only affects the SI mode DI and 2d are crystal clear. Inn going to update the software, after that I guess run a dedicated ground from battery to trolling motor casing. Already have noise filter set at max, and the unit is on a dedicated circuit ran off of cranking battery. Any ideas?

http://www.humminbird.com/Category/Support/FAQ/Trolling-Motor-Interference/

START by contacting Humminbird Customer Service for help with your RFI issue. They have the experience with that issue since using a Side Imaging transducer on a trolling motor is very common.

 

You have four frequencies that the trolling motor can affect. Yours is broadcasting on one or more of them.

BTW, there is no "one size fits all". Each installation is unique even if the trolling motor is the same model made the same day.

 

On high speed, the digital speed control is not used, That digital control is commonly the source of the RFI. So is a bent prop shaft, out of balance prop, or misaligned motor case.

 

It took me a couple of months to resolve it when I had it.

Thanks fellas, I had tried contacting humminbird first, live chat was closed for the day. Will be talking with them tomorrow, loving the hd display btw. I think the upgraded transducer was money well spent.

I had that problem. I did every thing HB told me to do. Installed the choke wire they had sent me. rerouted wires. Nothing worked. Water over about 10' it worked fine. Must be bouncing waves off the bottom in shallow water.

I had that problem. I did every thing HB told me to do. Installed the choke wire they had sent me. rerouted wires. Nothing worked. Water over about 10' it worked fine. Must be bouncing waves off the bottom in shallow water.

RFI has nothing to do with sonar pulse echos.

RFI has nothing to do with sonar pulse echos.

It would only do it in less than 10' of water depth. Anything over that it worked perfect.

Post a unit screen snapshot of what the unit is doing when you get "noise feedback".

Will do Wayne, my back its out right now may be a few days.