Interference...

I am running hummingbirds a gen 1 on bow gen 2 on console..i have them hooked directly to battery and not the trolling motor battery either. I also have added ground wire to skeg along with a round thing from hb...lol can't think of what it's called. I have a motorguide x5 trolling motor which I like. I still get interference on both units while using trolling motor. Question I have is if I switched to a minnkota would that solve the problem or is it just the nature of humminbirds?....thanks for any input as I'm at my wits end...

The round thing is a donut. If it in the power to the TM, it is a toroidal power inductor which is used to reduce common mode noise.

Have u tried tying the ground (most negative) of the tm battery to the ground of the accessory battery? Sometimes this helps.

You have a tin or plastic boat?

https://www.humminbird.com/faqDetail.aspx?id=3660

No I haven't tried that but I will...i have a plastic boat..

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Originally Posted by shortdraw

No I haven't tried that but I will...i have a plastic boat..

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Which frequencies is the noise showing up on?

One thing you might consider. I have all my HB stuff on one battery solely for their use. Nothing FF wise is on my cranking or TM batteries.
The guys above will help you get it figured out.
I'm just throwing this out, hoping it might be helpful.

Sometimes a common on-board charger can create a path for the interference to encroach into the Sonar unit ...

Rickie

Disconnect one unit from power and try individual. See if one works without noise on it. Could be a wire routing issue. Also, what everyone else said.

My Ulterra creates noise with foot pedal and not with remote. Donut didn't fix mine either. Totally rewired power distribution and routing. This problem is still unanswered. My fix is remote only.

The front in it is on 455 kHz console is mega at 1175 I think..power wires for f2f are on opposite side of boat from trolling motor...will try to run wire between negative on batteries. Do have a on board charger never thought of that being a issue...

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Originally Posted by shortdraw

The front in it is on 455 kHz console is mega at 1175 I think..power wires for f2f are on opposite side of boat from trolling motor...will try to run wire between negative on batteries. Do have a on board charger never thought of that being a issue...

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Yes. Chargers can have issues. They are silicon babies.

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Originally Posted by shortdraw

The front in it is on 455 kHz console is mega at 1175 I think..power wires for f2f are on opposite side of boat from trolling motor...will try to run wire between negative on batteries. Do have a on board charger never thought of that being a issue...

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On my boat.I can't run my 360 until I pull the fuses from my on board charger.Also,I use twisted power cables,that go to sonar units.I put one end in a vise.the other end,in drill motor and twisted them.

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Originally Posted by shortdraw

The front in it is on 455 kHz console is mega at 1175 I think..power wires for f2f are on opposite side of boat from trolling motor...will try to run wire between negative on batteries. Do have a on board charger never thought of that being a issue...

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Separating wires is a good practice. Are there any other wiring in the side of TM wiring? DC motor commutation creates RF, which creates the undesirable common mode interference. Air is a dielectric. RF can be coupled into adjacent wiring. If you have some spare wiring, you can wire to the TM bypassing your existing run ( lay it in the boat) and see if this reduces the noise. Try this if nothing simple works. Leave the wire to the TM housing in place.

Twisted wires is also a good practice for longitudinal balance. AG Bell discovered twisted wire applications in late 1800's. If it weren't for twisted wires, we could not talk (hear) via phone line, nor could we send/receive hi speed data. History lesson or a refresh on recall? Your call.

Another question??? Is the noise present when you steer or when you power the motor? Or both? That little steering motor is a big big source of RF.

I had similar issues with my trolling motor and sonar. I tried everything mentioned here and then added ferrite core filters on both positive and ground on both units and that solved all issues. The wires don't just pass thru the filters but pass thru and then thru the filter again causing a loop in the wire thru the filter. This was a last effort after everything else failed but it worked. Even made my am radio work properly. I suppose having a well grounded boat is comforting :). My problem was specific to only the upper frequencies associated with the down view functions of sonar.

Your AM radio was telling you that there was RF in the air. An am radio, tuned to lower band frequencies and turned to an "off or between active broadcast frequencies" can be use like a Geiger counter to find rf sources.

Thanks for all the info..I'll try them and see if I can't fix the issue. It's not horrible but still would like it to be clear all the time.

I realize that an AM radio was designed to pick up spark plugs firing in German airplanes during WW1 but the one in my boat still picked up the motor noise from my trolling motor, live well pump, and sonar. The live well pump and trolling motor caused drastic interference on the sonar. While I did not put the filters on so that I could listen to the radio still yet a side effect of the filters was that it cleaned up the radio. The initial design of the superheterodyne receiver in 1918 by US Army Major Edwin Armstrong is the father of all AM radios which is why an AM radio will pick up all RF in the area and transmit them thru the radio speakers. A test question I still remember from one of my earlier electronics courses. While I had my boat electronics grounded 7 ways from Sunday I still had interference in the 800 Hz range on my sonar as a last ditch effort I decided to place a few ferrite core filters in line with power and grounding on the offending components and my interference problems were solved.

Where can a guy get these ferrite core filters at?

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Originally Posted by shortdraw

Where can a guy get these ferrite core filters at?

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HB should send you ferrite cores ... They deal with customer issues with rfi every day ...

1-800-633-1468

Rickie

Ok thanks appreciate it...ill give them a call

The ferrites will suppress the rf in some cases. Sometimes it won't do enough. There is one that's good up to 20 MgHz bandwidth range. Get this one if you can. I dunno what HB sends in their survivor pack. Probably something in this range though.

I found it. It is Mix 75 from Palamor. It covers 260k to 20Mhz range. Of course, it boils down to trial and error.

Attachment 269587

I bought a set from eBay and put them on everything while I was replacing the fuse block. I had all the wires in my hand and figured it couldn't hurt. I am very pleased with the outcome. I had previously made sure there was a good ground on everything including the clamp that held the transducer to the trolling motor. I also insured that the trolling motor sonar unit got its power from the cranking battery and the helm sonar got its power from the trolling batteries

Ground metal things is a good thing. If it ain't grounded, it's an antenna.

Inside Diameter:	35.55 mm
Outside Diameter:	61 mm

These are BIG.

http://www.mouser.com/search/Product...623-2631803802

I stacked 2 of them & would my XDCR cable 9 times and it helped my RFI greatly.

These are 31 mix, the 75 mix Tom mentioned may or may not work better due to trial and error.