Minimizing Interference Risk On Installing Transducer Wire

[iceintheveins]

Anyone have any pointers on how to reduce the risk of interference when routing the transducer cable through to boat? The Transducer (a side imaging one) will be mounted on the starboard side of the stern. Should I keep the wires from touching any other wires or does it really matter? Could running the wire along the hull be a better option to avoid interference? I'm think I have the an unobstructed spot for the ducer, but I just want it free of interference.

[Roughwater]

I worked in Electronics/communications for many years.  As to avoiding interference it's best try to run lines  you want to protect so they are not running parallel to any electrical or transmission lines.  It doesn't hurt that much if the transducer cable crosses another line but if they are ran beside other lines or in the same wire bundle or conduit it can easily pick up interference.  It might be overkill for a transducer wire but running a wire through a grounded metal conduit can eliminate any chance of interference.  

 

Terry

[moguy1973]

I haven't had issues with my stern mounted transducer that is connected to my console finder but I have had interference with my front finder with my trolling motor mounted transducer when the trolling motor is on.  I've tried rerouting the wire being ziptied to the motor control harness to just on the motor mount but that really didn't fix the problem.  I've been told I need to get a ferrite noise filter to run the wire around a couple times to help negate the interference.  So if you do have interference that might be something you try.

[Roughwater]

1 hour ago, moguy1973 said:

I haven't had issues with my stern mounted transducer that is connected to my console finder but I have had interference with my front finder with my trolling motor mounted transducer when the trolling motor is on.  I've tried rerouting the wire being ziptied to the motor control harness to just on the motor mount but that really didn't fix the problem.  I've been told I need to get a ferrite noise filter to run the wire around a couple times to help negate the interference.  So if you do have interference that might be something you try.

Jim,

 

To eliminate the noise from your motor you could try using some kind of EMI shielding wrap around your transducer wire where it passes along the motor and the motor wireing.  Idealy it would work best if you solder or clip a wire to the wrap and ground the wire but you could try it ungrounded as it may also help.  This type of tape is not a sticky tape so would need wrapped with tape or something to hold it in place once it's wrapped around your transducer wire.  There are also shielded sheaths that kinda zip up around a wire but are generally more expensive.  Here is the product I'm talking about and can be found on flea bay etc: SCOTCH BRAND 24 ELECTRICAL SHIELDING TAPE TINNED COPPER WIRE BRAID 1".

[WRB]

Transducer cables are shielded coaxial and shouldn’t emit or couple frequencies used for sonar. The problem is usually the head units from different mfr’s operating on different frequencies that interfere.

Your TD that is mounted onto a trolling motor would be the susceptible component.

Tom

[Russ E]

8 minutes ago, WRB said:

Transducer cables are shielded coaxial and shouldn’t emit or couple frequencies used for sonar. The problem is usually the head units from different mfr’s operating on different frequencies that interfere.

Your TD that is mounted onto a trolling motor would be the susceptible component.

Tom

I agree. I have owned a couple with this issue.

 

Minnkota is notorious for this. 

They now run a separate ground for built in transducers,  because of this

The best way I found to fix this is run a seperate wire from the negative side of your graph battery, to a bare spot on the trolling motor head. If your transducer is mounted to the motor with a clamp, just make sure the clamp is touching bare metal and connect the ground wire to that.

[moguy1973]

On 3/9/2018 at 1:01 PM, Weedwhacker said:

I agree. I have owned a couple with this issue.

 

Minnkota is notorious for this. 

They now run a separate ground for built in transducers,  because of this

The best way I found to fix this is run a seperate wire from the negative side of your graph battery, to a bare spot on the trolling motor head. If your transducer is mounted to the motor with a clamp, just make sure the clamp is touching bare metal and connect the ground wire to that.

My transducer is mounted to the TM with a plastic bracket that came with the transducer then the bracket is secured to the motor using metal hose clamps.  I don’t believe the transducer touches the motor at all. 

[WRB]

EMI is interference from electro motive or magnetic pulses created by the electric motor.  Plastic is non conductive and aluminum is transparent to magnetism forces unless metalized by plating and transparent to EMI therefore couples to un shielded or non ground wires. About a decade ago most trolling motors were not grounded or incorporate a ground wire circuit and tended to interfere with some sonar units when running. Today most are shielded and use coaxial cables to eliminate EMI.

Tom

[Russ E]

9 hours ago, moguy1973 said:

My transducer is mounted to the TM with a plastic bracket that came with the transducer then the bracket is secured to the motor using metal hose clamps.  I don’t believe the transducer touches the motor at all. 

the transducer does not have to touch the motor housing to get harmonics or interference. the ground wire acts like a shield, that takes motor harmonics away from your transducer to the negative side of your graph battery.

when cables are shielded, one side of the shield has to be connected to a ground to work properly.

 

[PECo]

A buddy and I each have a Humminbird Helix 10 G2 and 24 volt Minn Kota Ultrex on the bow, and a second Helix 10 G2 on the console of our boat. We both had interference problems from Day 1.

 

After weeks of back and forth with Humminbird Customer Support, including installing a humongous ferrite core provided by Humminbird, he solved his by installing a second ground on the head of his trolling motor, just like Weedwhacker said.

 

I’m lazy and still living with it.