Topic: SI interference

[fishmanmike]

I got my 998c si installed and it works well. I am having trouble though when I run my trolling motor at low rpms. I get severe interference on the side scan and down scan screens. If I increase the rpm's the interference goes away. I don't get any interference from my primary motor. Any ideas on how to resolve this?
 
 

[bobcoy]

More than likely it is RF interference. Most trolling motors use pulse width modulation and unless you put them on full power they put out radio waves that show up on your depth finder as lines or just a solid blob of interference. If you call support they will probably send you an interference kit. It helped me out with my Minn Kota interference. Bob

[fishmanmike]

Thanks for the reply, I will give that a try.

[fishmanmike]

I guess i need to clarify my statement. My trolling motor is a mercury 9.9 outboard. It has resistor plugs in it.
 I talked with Humminbird and verified tha I have nickle insulated transducer wires. They are tryin gto tell me it is turbulance but I know that is not correct. I should be recieving my sd card today or tomorrow so hopefully I can get back up to the lake to get some snapshots of the screen to send them.

[Jolly Roger]

Mike,
can you post some pictures of the transducer location (from side and rear/front) and where the TM is mounted. I guess you got the transducer on the transom and the TM on the bow, right?

Regards / Harry

[fishmanmike]

Here are some picts of the transducers. You can see the Black Mercuy outboard shaft is well aft of the left transducer

[RGecy]

Mike,

Some pictures/snapshots of what you are seeing on the screen will help a lot! 

Like the boat! 

Robert

[fishmanmike]

Thank You, I just recieved my sd card in the mail today and figured out how to work the snapshots on the simulator and save them in my computer. Now I just have to find time to get back up to a lake to get some samples of what is going on.

[Humminbird_Greg]

It could be motor noise interference instead of RF-trolling motor interference.  Try some of the suggestions shown here on the web site:
http://www.humminbird.com/support/FAQ.aspx?faqtopic=17

[fishmanmike]

Well, as far as my office is concerned, I had a very important meeting to go to this afternoon. Which really meant I got up to the lake to get some screen captures. I methodically turned things on or off and realized it is my TR-1 auto pilot causing the problem . It creates no interference in standby but when it is steering ,that is when I get the problem. What can I possibly do to correct this?


<a href="http://s110.photobucket.com/albums/n85/fishmanmike/?action=view&current=noisefilterhigh.png" target="_blank"><img src="http://i110.photobucket.com/albums/n85/fishmanmike/noisefilterhigh.png" border="0" alt="noise filter high">[/url]
<a href="http://s110.photobucket.com/albums/n85/fishmanmike/?action-view&current=noisefilterhigh.png" target="_blank"><img src="http://i110.photobucket.com/albums/n85/fishmanmike/noisefilterhigh.png" border="0" alt="noise filter high">[/url]

[fishmanmike]

Picture 2 shows the interference, Picture 3 shows turning the autopilot from active to standby.

[sonar2000]

Mike, is the jet drive running when this happens.  Chuck

[Humminbird_Greg]

Fishmanmike,
You can try isolating the Humminbird and the Autopilot from each other: route any cables as far away from each other as you can.  Power them off of separate batteries.  Although made for interference from trolling motors the trolling motor interference kit from Humminbird may help with this.  Give them a call at 1-800-633-1468 and see if they can get one shipped out to you.

[fishmanmike]

Thanks Greg, I e-mailed the same photos to Ms. Smith at Humminbird so hopefully she will respond soon. Mike