Gt54 interference under TM

[mram10us]

I have an ultrex with a gt54 i mounted on the bottom. Picture is fine with TM not running. When I step on the pedal, aka, the TM prop is moving, there is noticeable interference on the screen. Ferrite bead on transducer cable near back of graph. Ideas?

1. has nothing to do with ultrex puck since it is only when power is applied to motor

[Coastal Mountaineer]

I've got the same issue and it's getting worse. When first mounted, interference was just some vertical lines. Now the entire screen is messed up.

[mram10us]

So far, if the fuse is good in the tm head, then it might just be vibration and not em interference. I'll try taking the ducer off and holding it while running the tm prop to see

[Triton420]

So far, if the fuse is good in the tm head, then it might just be vibration and not em interference. I'll try taking the ducer off and holding it while running the tm prop to see

Same thing with mine on the Fortrex. No fuse in head, clears up some when at 100%.

[mram10us]

1. wrapped the section of the wire from ducer that goes around the motor housing with faraday tape.
2. put two layers of faraday tape between the ducer and plastic tm mount
Still had interference when testing in garage. Could be vibration?? More testing

[fishin couillon]

Also do testing on the water.....

[Bill Reynolds]

A quick way to determine if the interference is RFI from the trolling motor speed control is to set the dial at 100% and engage the motor. When set at 100% the signal is essentially analog and should not generate any RF waves, therefore you should not show any disturbance on the screen.

The reason I mention this is that there is also electro magnetic interference generated at the brushes but Minn Kota has done a pretty good job of taking this to ground. There is a fused wire connected to the commutation plate and routed through the head of the TM to a ground wire of the boat circuit. If this fuse is blown you get severe interference.

The only advice I can offer for RFI is to not route the transducer wire down the steering cable sleeve. The TM power wires are routed inside the sleeve and it acts as an antenna. This picture does not show the GT54 mounted on the TM but I added it later and routed the wires along with the others.

I have a slight amount of interference on 2D sonar but not enough to concern me.

EDIT - I forgot to mention that my 10 inch Ultra and LiveScope is powered from a separate lithium battery in the starboard locker.

[mram10us]

Also do testing on the water.....

Not an option right now, unfortunately. I agree though

[mram10us]

Bill, I'll try running the wires away from the tm sleeve. Thanks. Might even re run my LS cable while I'm at it

[aj306]

I’m new to Garmin but on my last units changing to a different megahertz helped more than anything

[mram10us]

I’m new to Garmin but on my last units changing to a different megahertz helped more than anything

I'll re run the wires like Bill shows, then try changing freqs. On 2d, what freqs did you try? Chirp gives a small band of freqs

[mram10us]

Alright, re ran the wires on the side per Bill and it works great! Thank you gents!