RF/TM noise interference improvment (597ci HD DI)

Last week I was informed of RF/TM noise on screen shots of my new 597ci. Here's waht I was seeing at trolling speed .8-1.0....
.Attachment 86509.Attachment 86508

After doing some research I rerouted the transducer wire away from the coiled power wire and installed a pair chokes on the TM power cord. Here was the result...(setting were 9 sensitivity, 9 contrast with surface clutter set to 1, noise filter set to high1)Attachment 86510Attachment 86511.
Not quite what I wanted but I could live with it if neccessary. But I continued to reasearch the subject.
RF Chokes installed...Attachment 86512.

Today I twisted a 18 gauge wire around the transducer wire and spliced it into the negative wire on the sonar unit (tried the neg. wire on the TM power with no results) and anchored it to the clamp on the TM motor. Here is the result...(sensitivity set to 12 (14 was clear as well), contrast 10, surface clutter 5, and noise filter off)...Attachment 86514Attachment 86515.

Still needs some tweaking on sharpness and whatnot, but as can be seen there is very little RF/TM noise showing on the unit while the TM is running at trolling speeds. Need less to say I am very happy now.

The fix....Attachment 86517Attachment 86516Attachment 86518

Did you pick those chokes up from radio shack?

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Originally Posted by Superx10

Did you pick those chokes up from radio shack?

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Yes...Snap-Together Toroid Choke Core-2-Pack

| Catalog #: 273-104

Snap-Together Toroid Choke Core-2-Pack - RadioShack.com

Was the 18 ga a suggestion from Humminbird? Haven't seen that one before, unless I missed it. How far back with the 18 ga did you go before splicing into the power cord?

thanks

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Originally Posted by vic n

Was the 18 ga a suggestion from Humminbird? Haven't seen that one before, unless I missed it. How far back with the 18 ga did you go before splicing into the power cord?

thanks

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I used 18 gauge since I had some on hand from installing the unit....Humminbird said to run a wire (18 gauge being acceptable) from the skeg to the negative side of the of the battery. I tied it in where I had splice the power wire to lengthing it during installation, about 5 ft back. Decided to try anchoring it to the clamp before drilling holes in my Powerdrive.

You don't have to drill hole's in your PD and would not suggest it.I took mine to a authorized minnkota repair center and had them install a ground internally.Problem solved.

I would like more info on grounding the trolling motor...

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Originally Posted by Dutch

I used 18 gauge since I had some on hand from installing the unit....Humminbird said to run a wire (18 gauge being acceptable) from the skeg to the negative side of the of the battery. I tied it in where I had splice the power wire to lengthing it during installation, about 5 ft back. Decided to try anchoring it to the clamp before drilling holes in my Powerdrive.

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And what about the "wrapping" of the 18 ga? Was that just for convenience to not have another wire flopping around, or is it supposed to help with the noise?

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Originally Posted by vic n

And what about the "wrapping" of the 18 ga? Was that just for convenience to not have another wire flopping around, or is it supposed to help with the noise?

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Wrapping the wire helps with the shielding...the tighter the wrap the better it will shield.

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Originally Posted by Superx10

I would like more info on grounding the trolling motor...

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Here you go... The #1 FIX

AAARGH! Sonar Noise! - The #1 Fix

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Originally Posted by striperking

You don't have to drill hole's in your PD and would not suggest it.I took mine to a authorized minnkota repair center and had them install a ground internally.Problem solved.

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I did not drill any holes I wrapped the wire through the clamp and cover the bare wire with liquid tape to seal it.

I'm not wanting to put a hole in the skeg to run a ground wire

They took mine apart and ran a wire down the shaft to the motor housing and connected it to something in the motor housing.A good minnkota repair man should know what to do.I then took the wire and connected it to the negative side on my trolling motor plug.I let them do it so the motor would be sealed back correctly.Mine totally blocked out my screen and it would only show up when the TM was in the water and turned on.Totally fixed all my interference.If you need anymore info PM me your cell# and I will call you.

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Originally Posted by Superx10

I'm not wanting to put a hole in the skeg to run a ground wire

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ONCE AGAIN: I did not drill any holes I wrapped the wire through the clamp and cover the bare wire with liquid tape to seal it

How did they route the wire? In the coiled wire?

..that hole in skeg comment was towards the #1 Fix

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Originally Posted by Superx10

How did they route the wire? In the coiled wire?

..that hole in skeg comment was towards the #1 Fix

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I also did not want any holes in my Powerdrive, so thats why I experimented with a different way to connect the wire.

That's what it looked like. clamped and sealed to the motor.

That's why I went inside with my wire to have a neat installation and no hole's.

striperking, do you have pics of where your wire comes out? or any visual of what they did?

Great info on this, thanks for sharing. Did you have to scrape the paint off the housing to get good contact with the hose clamp?

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Originally Posted by brobrash

Great info on this, thanks for sharing. Did you have to scrape the paint off the housing to get good contact with the hose clamp?

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No...I was going to scrape it off, but decided to try it first with the way its done. It worked, so I called it good and went fishing.

That is amazing and mysterious. Must be working like a lightning rod or possible shield open end. Must have some resistive ground. Otherwise you have a 20 foot antenna or whatever the wire length is. Wish you were closer. I would like to put my scope and meters on it.

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Originally Posted by Cane Pole

That is amazing and mysterious. Must be working like a lightning rod or possible shield open end. Must have some resistive ground. Otherwise you have a 20 foot antenna or whatever the wire length is. Wish you were closer. I would like to put my scope and meters on it.

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Yes it is...thats why I posted screenshots. And it worked for me. but with the way RF/TM interference operates it might not work for someone else.

Very likely one of the best treads on the subject and makes lots of sense. Might consider to add to the sticky. thanks again Dutch.

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Originally Posted by brobrash

Very likely one of the best treads on the subject and makes lots of sense. Might consider to add to the sticky. thanks again Dutch.

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Thanks...and I posted it under the sticky as well.

Do you think wrapping the wire helped or was it just the grounding?

Everyone should learn the right hand rule as applied to electronics and wiring and learn what causes noise in the first place. Look up right hand rule. Might learn something!

Awesome info! Thanks.

Sent from my BlackBerry 8530 using Tapatalk

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Originally Posted by brobrash

Do you think wrapping the wire helped or was it just the grounding?

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Probably the grounding as well as wrapping it...I tried it with running it straight as I had read about and there was a little improvement. Then tried wrapping it and it cleared up alot better. Just experiment...what worked for me might not on yours...but I shared this so that at least others with this problem (and it seems from my research to be widespread) will have some different ideas and a starting point to remedy this issue on thier units.

Thanks for all the info my 788di and fortrex tm had simular problem i added rf chokes by trolling motor pedal,grounded tm housing then twisted 14ga wire around transducer cable then ground it to cranking batt and twisted 788 wires pos/neg wires to crank batt my problem is gone thanks again

There was an update to software that fixed mine