TM interference

[Jford2131]

I am looking to get some insight/advice on possible resolutions with interference on my fish finder. Equipment in a Garmin 73cv, transom mounted transducer, with a Riptide TM. I have taken the the steps below, but cannot get the screen clear while trolling or spot locked.

- ferrite rings on transducer cables and trolling wires
- ensured no linkage between TM batteries and house battery
-Ohmed negative terminals to ensure not continuity
- Adjusted gain and surface noise on unit
- ensured no other power wire is running along transducer cable
- puck is hard wired to battery with inline fuse, was first ran to accessory switch on helm panel

Any and all advice is greatly appreciated!

 

[Dumbassbass]

I am looking to get some insight/advice on possible resolutions with interference on my fish finder. Equipment in a Garmin 73cv, transom mounted transducer, with a Riptide TM. I have taken the the steps below, but cannot get the screen clear while trolling or spot locked.

- ferrite rings on transducer cables and trolling wires
- ensured no linkage between TM batteries and house battery
-Ohmed negative terminals to ensure not continuity
- Adjusted gain and surface noise on unit
- ensured no other power wire is running along transducer cable
- puck is hard wired to battery with inline fuse, was first ran to accessory switch on helm panel

Any and all advice is greatly appreciated!

Have you looked at the underside of the trolling motor mount? There are stereo and navigation wiring through the underside of the gunnel that may have a ground wire pinched (TM ground shorting to House system ground).

Is the image free of interference when the trolling motor is not powered up?

Powered up but TM motor not actually turning?

Do you have on-board chargers connected to the trolling motor batteries and if so have you tried to disconnect the leads to see if symptoms differ?

 

[Jford2131]

Have you looked at the underside of the trolling motor mount? There are stereo and navigation wiring through the underside of the gunnel that may have a ground wire pinched (TM ground shorting to House system ground).

Is the image free of interference when the trolling motor is not powered up?

Powered up but TM motor not actually turning?

Do you have on-board chargers connected to the trolling motor batteries and if so have you tried to disconnect the leads to see if symptoms differ?

I do have a 3 bank on board. After the rings were installed I removed the the leads that connected the TM batteries, still had the same results. The interference is only when the TM is spinning. Fish finder was clear prior to installation. When powered the screen is clear, when running wide open it is clear. However at low speed and spot lock, I have heavy distortion. I have inspected the wires underneath the mount plate and the gunnel. The TM does not have a factory internal ground, I was thinking that is probably my next step.

 

[HangOutdoors]

Do you have pic of what you are seeing on the screen?

 

[Dumbassbass]

I do have a 3 bank on board. After the rings were installed I removed the the leads that connected the TM batteries, still had the same results. The interference is only when the TM is spinning. Fish finder was clear prior to installation. When powered the screen is clear, when running wide open it is clear. However at low speed and spot lock, I have heavy distortion. I have inspected the wires underneath the mount plate and the gunnel. The TM does not have a factory internal ground, I was thinking that is probably my next step.

You could try bonding the grounds, mine are completely independent.

Can you trace the exact route of the transducer cable, making sure its not chaffed or pinched?

Have you tried removing the transducer completely during interference to see if it goes away? my thought here is that the motor itself may be producing EMF or RF leakage. And without the transducer but still having "interference" would be the electrical system. if only while the transducer is in the circuit may be acting like an antenna. Times like this are when you wish you had an extra transducer to swap out or a buddy with the same TM to see if it's a hardware issue.

I ran a 4 gauge ground bus from my console directly to the house battery so I knew I wasn't receiving any ground loop issues through other devices. Can cause humm and other undesirable issues on all electronics.