Terrova/Humminbird interferrence

Just wondering if anyone is or has had this same experience. I have a new Minn Kota Terrova 80 (which I deeply love) and a new Humminbird 788ci HD DI on my "new to me" boat. The boat is a 2008 SeaArk X176. When useing the humminbird up front with the built in transducer on the troller, I get interferrence on the 788 screen whenever the troller is turned on. The weird part is that when I turn the speed of the troller all the way up to full power (10) it clears up. I like to long line troll for crappie in the spring and would like to be able to see what is going on down there at speeds other than full. All of the rest of the info seems to be OK, just the 2-D pic is distorted. Any help is GREATLY appreciated.:confused:

I had the same problems and adj. the sensitivity helped some, tried to get the nois cancelling kit from humminbird but never got it, I hear it will help a great deal, funny thing the terrova was the only trolling motor that interfered with the unit, so I guess the unit is ok, it just doesn't like the terrova, good luck

Yep, had the same problem with my 788 and terrova. I unhooked the US2 transducer and installed the factory one...problem solved.

hb sent me a pc11powercord and i set the noise filter on the unit on 3 that corrected mine.

feelay: how did you install a factory transducer on the terrova, I mean, what did you do with the wire? pic maybe?

travish10,
You need to call the Humminbird Customer Resource folks about this. 1-800-633-1468
They will have some suggested fixes for you to try. Be forewarned though: what works on one boat does not work on all boats.

What you are seeing is RF (Radio Frequency) interference from the Pulse Width Modulation (PWM) circuitry in the trolling motor. This circuitry is used for all but full speed so that is why you don’t see it than.

I did call Humminbird and after a 40 minute phone call, most of which was waiting for someone to pick up, I may have it fixed. They first told me to take the cover off of the Terrova and pull the 3 amp fuse and put an ohm meter on it to seen what it read. Mine was reading anywhere from .3-.6 ohms. They said that it was good. They also said that a visual check was not good enough, hence the ohm check. Anyway after that was done, they said that they were going to ship me a new power cable that had a "filter" in line. The cable is only six foot (same as the one that came with it) and I asked if they had a longer one because I had to extend the original one with my own wire to reach the power feed. They said that it should be OK because the "filter" would clean it up at the head unit. I don't have it yet but should be getting it next week or so.

Humminbird Greg:

If this doesn't help (new filterred cable)do you have any suggestions to deal with the PWM in the troller? Would Minn Kota be able to do anything?

To tell you the truth travish I don’t know what Minn Kota is doing from their end of things. I would give them a call anyways and see what they have to say.

The only suggestions I have is to call Humminbird back if the filtered power cables does not fix it. There are different steps of things that they should be taking you through to try and get our unit to work with the interference from the trolling motor. Unfortunately what works for one boat does not work for another.

I have different units than you, but had a similar problem with my bow-mounted 898 and my Terrova 80. I got the interference kit from HB but it didn't solve my problem. Called Minnkota and they sent me a wire with an inline fuse to connect between the negative of my trolling motor battery that goes to the Trolling motor and the negative of my starting battery.

Problem solved. The little fuse blew one day and the problem came back, changed the fuse, problem went away.

As someone mentioned, every situation is diff't, so what solves one may not solve another.

Quote:

---

Originally Posted by travish10

feelay: how did you install a factory transducer on the terrova, I mean, what did you do with the wire? pic maybe?

---

Just like this....

http://www.crappie.com/crappie/fishi...cer-mount.html

Hey gang,
Sadly, I'm dealing with issues with my 596c HD DI mounted to Terrova also. Mostly dealing with the depth jumping all over the place in shallow water. I have tried all setting adjustments suggested by HB and Greg to no avail. The depth issue I find occurs even when trolling motor is not running, however when motor is deployed it is powered up.
I have a pull start, so have a stand-alone battery for trolling motor, and a little 12v rechargeable mounted to the outside of the battery box for the HB, Cabela's: Cabela's Rechargeable 12-Volt Battery

Would it be a good idea to run a fused wire between the two negative terminals in this setup, or is that a bad idea as the little rechargeable is only an 8-amp?