Noise on sonar

[leeb]

Any tips on how to stop noise on sonar. I have my trolling motor on a separate circuit/on different batteries completely. When I engage y trolling motor I am getting a little noise in my sonar. The noise is most noticeable on side and down imaginig.i get a 45 degree angle marks like "/" on the regular sonar and a fog or milky look on the side imaging.

I believe I will try to to twist my trolling motor wires and power supply wires to the sonar unit first. If that does not help I think I will try to wrap my transducer wire around my trolling motor wire a few times.

Has anyone ever ran into this before and know what I need to do to remedy this.

[mwardncsu]

I've got a good link tucked away somewhere that gives a variety of steps to work through. I'll try and find it - could not put my hands on it in a quick look.

A few things:
- seperate the Transducer wire from the power wires as much as possible
- try a ground wire between the ground on the TM batter(ies) (only one terminal - the ground potential if a 24 or 36 V system) and the ground of the battery your electronics are connected to. FUSE THIS WIRE - there is potential for this wire to have a voltage differential and thus carry current
- what TM do you have? Some have a ground wire inside housing from motor to case - some don't (but can be added). This often is the thing that ultimately fixes it - Ben McCall at SML Marine Electronics can add one.
- check out some ferrite clip ons that you wrap the TM power wires in. Or - Humminbird has a product for sale that does this and has solved the issue for many

It is kind if a hunt and peck thing till you find what kills the noise in your setup.

[striperjohn]

Hey Leeb,
If you have your main usually rear mounted puck, on the same time as your trolling motor unit it will cause the interference you're talking about. It you have the ability to switch one unit to a different frequency that will resume your problem. If this is the cause of course.
I've noticed that I have the problem when I'm near what appears to be a rock wall underwater and a hard rock bottom. Double and triple echos can occur as well.

[mwardncsu]

Finally found the link (well, actually had to get someone that I had sent it to before find it and send it back to me - thanks Mark!

mysite.verizon.net/restmvit/tmintf.html

[leeb]

I installed a ground wire this weekend from the trolling batteries ground to the cranking batteries ground. That cut the noise by 50%. I will need to run new power and ground wires next. I plan to try and find some 18awg microphone cable. If I can find that with two strands for positive and negative it will be shielded. Then I will ground the shielding for the faraday effect.

If that does not clear it all up I will need to buy an extension cable to be able to reroute the transducer cable. The factory cable only has about 4 inches of slack now to make a run straight as possible. The problem is that run is parrallel and close to the trolling motor cables.

[mytoyzfishing]

If you are still in the hunt for microphone wire check with Lee Hartman in Roanoke. They should be able to find what you are looking for.

[leeb]

The final fix was running a ground wire to the trolling motor housing.

The 2013 motors from Minnkota will come with the ground wire already installed internally.

[mwardncsu]

Lee - Where / how did you install it - on a Terrova or Riptide?

[leeb]

Riptide st 101 ipilot

I ran a ground wire all the way through the shaft to the bolt that holds the brush assembly in place to the housing.

I should have simply taken the prop off and taken the two bolts out that hold the motor together out. Then install a ground wire from the factory ground(black) wire to the bolt that holds the brush assembly to the housing.

I was fed up and wanted to make sure I fixed it. This was cutting into my fishing pleasure time. There is enough frustration in tangled fishin line to deal with instead of be pissed off about $4000 in electronics.

[mwardncsu]

thanks - I need to give that a try on mine...... I believe SML Marine Electronics can also do this if you don't want to tackle it on your own.....

[leeb]

He wanted $80. I just did not feel like taking the time to drive to the lake just to take him my trolling motor and another trip to pick it up.

So I took it home and had it ready for my next trip.