It has been requested that we have a sticky just for RF type interference with electronics. So this is the place to post your problems and cures for such type problems.
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It has been requested that we have a sticky just for RF type interference with electronics. So this is the place to post your problems and cures for such type problems.
Good idea Bill...
Let me get the links to these in here right at the first..
Trolling Motor Induced Sonar Interference
http://notjustfishing.com/MotoGuide.pdf
This was Canepole's and DonG's idea. I think It could turn into something good.Quote:
Originally Posted by rnvinc
Here are a couple more references from Humminbird.
Humminbird: America
Humminbird: America
Call these folks about your ferrite core needs for RFI. They are the toroidal donut experts.
Toroid cores for amateur radio
RF interference after initial set-up. This noise was on SI & DI(455 & 800) with no noise on 2D.TD is mounted on TM
Attachment 75909
After re-routing my TD cable the noise still remained on 800kHZ but was clear on 455kHZ.
After installing the TMC-1 this is what I now have. Clear on 455 and very little on 800..I will live with this until I visit Tom..:)
I have no idea what the white horizontal line is on the DI..It shows up when I select 800kHz even with the TM unplugged.:confused:
Attachment 75910
I have been working on my TM, so I thought I would make this short video so someone might relate to what is going on with pwm as related to noise and speed of the TM.
You will see the noise spikes near the end of the video. I did some rough calculations of the noise frequencies present. The noise ranged between 1 megahertz down to 100 kilohertz. These noise frequencies fall in the band of the sonar transducer frequencies. (RF). That is why you see it on the screen. This is just a show and tell and does not cover all the noise sources of RF.
Hope it make sense to someone.
http://i188.photobucket.com/albums/z...h_PWMNoise.jpg
Wanted to add that the fundamental frequency of this PWM is 20Hz. So, what you see is a 20Hz modified square wave. When you run wide open, the bottom line goes straight, meaning a solid ground is supplied through the FET to the negative side brush of the motor so there would be no pulses, therefore no noise at WOT (kinda). The reason the pulse fundamental frequency is so low (20 Hz) is because at higher pulsed frequencies, you can actually hear the motor squeal like a pig. When you hear that "click" everytime you hit the foot switch, well, that is a 50 amp relay operating which places 12/24v to the positive motor brush. This is a coasting relay which prevents regenerative braking. In other words, the motor coasts to a stop instead of stopping suddenly. Electric choo choo trains use regenerative braking to slow down. Disc brakes don't work too good on choo choos.
Where would you be able to find an RF Choke describe in the article by Motorguide?Quote:
Originally Posted by rnvinc
Thanks
That is just a ferrite core. You can get them at Radio Shack.Quote:
Originally Posted by crappiemax
Okay that should be easy, thanks.Quote:
Originally Posted by Barnacle Bill
One more question, do they come in sizes or is it a size fits all kind of thing. This is all foreign to me.
I do steel work, here we fix everything with heat and hammers.
For the tough stuff we use more heat and bigger hammers.
Again thanks for your help.
This is a great thread. I noticed some interference in my HDS I just hooked up a few weeks ago and it's hooked to a Motorguide tour. The timing is perfect.
RadioShack® Snap-Together Ferrite Choke Core - RadioShack.com
Wrap the positive wire around it a few times then close it. Install it as close to the unit as possible.
Thank you so much, I'm headed there tomorrow night after dinner.
Twisted pair wires
http://www.crappie.com/crappie/fishi...erference.html
Sorry if this is a redundant question, but I want to make sure I do this right tomorrow. For the twisted pair I only need one black and one red cable from my battery to my 788. I just twist them around the hook them up as normal. Thanks
You got it.Quote:
Originally Posted by jsplinter
Tried the twisted pair and even rerouted my wires so they are on the opposite side of the boat that my trolling motor wires are, but still the same results
ok, has anybody figured this rf interference out? I have a humminbird 858 di with a ton of interference..... banghead
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 86840Attachment 86841
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 86842Attachment 86843
Not quite what I wanted but I could live with it if neccessary. But I continued to reasearch the subject.
RF Chokes installed...http://www.crappie.com/crappie/attac...i-img_0006.jpg.
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 and covered the exposed wire with liquid tape. Here is the result...(sensitivity set to 12 (14 was clear as well), contrast 10, surface clutter 5, and noise filter off)...http://www.crappie.com/crappie/attac...-di-s00021.jpghttp://www.crappie.com/crappie/attac...-di-s00023.jpg.
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....http://www.crappie.com/crappie/attac...i-img_0002.jpghttp://www.crappie.com/crappie/attac...i-img_0007.jpghttp://www.crappie.com/crappie/attac...i-img_0005.jpg
Cane Pole, so would using the rectangle snap-in chokes wrapping both power and ground wires work better or worse than just using the single wire long rectangle snap-in choke to wrap the red power wire?
Both wires. I talked to Palomar engineer and he recommended 5 turns on a ferrite toroidal.Quote:
Originally Posted by Superx10
Call them. Tell them your issues, and they will recommend a possible solution. They know a lot more than I do about noise.
Palomar Engineers | Amateur Radio
Having some interference issues tried a RF choke with no help then grounded the 24 volt TM batteries Neg post only (per instruction on the sticky) to the starting battery with no help. Should I leave it grounded for any reason?
I did adjust the RF setting from the menu of the 597 and 798 I can’t remember what it was called but that did take care of most of my interference issues. I'm not sue what else to try. It mainly happens on the 597 when I engage the TM but only on start up.
Also I’ve seen some people put the choke on the TM power cord/plug……mine is on the power to the graph, which is correct or is there a correct answer? It’s just a magnet right?
Hi, I have a question with regards to this. I have a Motorguide Wireless 55 and my side imaging goes to crap if the trolling motor is on anything other than full blast. Can't see crap. Totally hazy. I am trying to figure this out. I am also getting some white residue on parts of the motor housing like the skeg where it has been scratched. Seems like an electrical charge attracting something. What I did was to run a wire from the steel transducer clamp and tie it into the ground for my horn (easiest to try). This did not work at all.Quote:
Originally Posted by rnvinc
After reading the first link, for #4 and #5, is he saying that I should run a ground from the TM ground to the motor AND one from the graph ground to the motor? Or is he saying that is a second option? Also, any other thoughts on how to cure this ridiculous problem are appreciated.
Don't know much about the white stuff but I cured most of my RF inteference buy wrapping my TM wires around 2 RF chokes right at the TM plug. I used 2 chokes and wrapped the wire 2 times on each of them. I didn't have much luck adding the grounds but these issues for each unit are unique to different boats. You just have to keep trying to different things until you find something(s) that work for you.
Do the Lowrance Elite 5 DSI FF/Chartplotters have thesame problem with interference as the Humminbird DI units? I use a Minn Kota VariableSpeed TM.
Thanks,
FlyBye
RF interference is often confused as a "DF problem"....Quote:
Originally Posted by FlyBye
We always have to remember that interference is created somewhere else in the boat...the DF's today are just sensitive enough to pick this stray interference up...
There is no accurate way to predict if any certain DF unit will have interference issues...
Your boat setup...(the interference culprit)...may or may not create interference...
Rickie
Any thoughts as to why this interference happens on all speed settings except full?
When a trolling motor is at the full speed or WOT setting it is not using the Pulse Width Modulation (PWM) circuitry that it has to maximize the battery life. Therefore it is not generating the RF signal that is causing the interference.
Thanks Greg. Do you think I should start with the TMC-1 then? I am just hesitant to cut wires if it isn't necessary.
I would do whatever the Customer Resource folks say to try first as the TMC-1 does not always help.
OK, I haven't contacted them. The unit is a used 798c si. The one I purchased new is a 798ci si. The internal is at the console and the external is at the bow near the TM. My internal is out of warranty at this point so I wasn't sure they would help? I'll send an email and see what they say.
Yes they will help anyways AZ.
Calling them will produce better results than an e-mail.
Thanks again Greg. I didn't even realize that I could call. I talked to a nice gentleman by the name of Nagee. He is sending me a ferrite ring and instructions. He said if it doesn't work then to call back. I tell you what. Not enough companies have customer service like Humminbird does! Thanks again. I'll post back after I get it and try it.
Well, I finally got the boat out yesterday. The ferrite ring seems to have done the trick! There was no interference like what I was seeing before. There were some minor things but I am not sure what they were so a little more time with it and I should know for sure but I am amazed at the difference in clarity! Such a simple fix :D
I was experiencing terrible RF interference between my Terrova with US2 and two different greyscale HB units-a 718 and a 570. I ran #6 wire to the TM and had it mounted as far away from my sonar cables as possible. I added the HB choke on the recommendation of the HB customer care center-no go. I also purchased 4 additional ferrite cores and placed them in series on the HB power cord as close to the unit as possible-no go. I still had interference issues that made the unit useless most of the time on the water, as all but the top 5-10 feet of water were completely blacked out. I was about to sell the Terrova on Craislist and deciced to try one more thing. I installed a Lowrance x135 unit up front and connected it to the US2 and no interference. I have fished it for the last 2 months from water depths of 3'-88' with no RF interference whatsoever.
I'm not making this out to be a HB vs Lowrance thread as I have always been a dedicated HB customer and have an 898 on the console. I just wanted to give others hope and explain the way that I ultimately got rid of the interference and still get to use the awesome features of the Terrova.
597 di goes crazy when I touch TM workers great on 100 percent . I have it mounted on my maxxum 80 variable speed. What good place to start to fix this. It is hook to start batt
I would start by making sure that the software in your unit is up-to-date (version 6.090) and if it is, call the Humminbird Customer Resource folks at 1-800-633-1468.
Same problem but what worked for me was a couple of RF chokes on the Power Cord for the finder and re routing the transducer cable pictured below. Good Luck.Quote:
Originally Posted by Hunterjt
im having the same trouble , terrova us -2 humminbird 858 c hd , what is a tmc-1 i looked on humminbirds sight and could not find it ?Quote:
Originally Posted by Don G