noise on D/Finder screen from TM

[pantherdev]

I have a transom transducer mounted on my new MK power drive v2.  I got the mount off the internet and it worked well to mount the ducer.  However I cannot get rid of noise on screen when the motor is being used, even with a 3rd seperate battery on the sonar unit.  Is there a fix or do I have to purchase a puck transducer?  Does a puck transducer have additional RF stuff in it?  This unit is a Humminbird 727.

[NBR]

Thie ia a what I have heard reply not one of personal experience. I have heard that if you run the TM and sounder off the same battery you can get noise on the sounder. Sounds like you don't run both off the same battery.

I have run the puck off the TM with out a problem. I'd check with with MK.

[Wayne P.]

PM sent

[fishfordollars]

IM sent, Welcome to the forum.

[Glenn]

This should help you:

http://www.bassresource.com/fishing/electronic_interference.html

Enjoy!

[Fishing Rhino]

Back in the day, when I was lobstering, I had just acquired a Loran C unit. 

Hooked it up, turned it on and it functioned perfectly.  Quickly acquired the signals and displayed the time delays that in conjunction with a chart allowed you to accurately fix your position.

But, when I headed out to sea, the numbers began dancing around and SNR appeared in the display.  The signal to noise ratio prevented the loran from acquiring a fix.

Figured it was from the alternator, so I fashioned a shield from hd aluminum foil and set it above the alternator so it was between the antenna and the alternator.

Problem solved,....... temporarily.  Temporarily because I had no way of keeping the makeshift shield in place.

The problem was permanently solved when I got the proper noise suppressor from the electronics shop.  It was a simple matter of removing the charging lead from the alternator, connecting the suppressor to the alternator, and then connecting the charging lead to the suppressor.

I am inclined to think that there must be some type of suppressor to squelch the "noise" be it transmitted by the wiring or whatever.

I'd check with someone who makes their living dealing with marine electronics, sales and service.

There has to be a fix that will allow you to run your sensitivity setting at any level.

[pantherdev]

OK, I have been in touch with Johnson Outdoors and in less than 5 minutes yesterday the CS rep was taking my name and address to send me a kit with the RF limiting devices in it.  It came today and I will install next week.  I hope it will not limit the amount of signal I get from the bottom so as to make my Humminbird dumber.  I commend Johnson Outdoors for their excellent CS and will buy another product from them when the opportunity arises.

[Wayne P.]

RF chokes do not affect the sonar processing signal from the transducer. What parts were sent to you?

I have delt with that issue also.

[pantherdev]

Some item to put in the actual power cord (with and oblong donut) for the motor and a new power cord for the DF with a similiar looking round donut in the cord.  There were several ferrite rings too whick I will not need due to not having universal sonar in the motor head.

[Wayne P.]

Thanks, I got the chokes but not any of the ferrite rings. Here is the TM choke installed on mine

[pantherdev]

Thanks, I got the chokes but not any of the ferrite rings. Here is the TM choke installed on mine

Did you install both chokes before you tested for noise again or did you install just one and test to see if both were needed?  Thanks Wayne for the pic. It is exactly what they sent me.

[Wayne P.]

I already had the power cord (came with the unit) with the built-in choke and a couple more of them without the choke ( for the Matrix 97 I have ) so I already knew that did not solve the RF issure. After I added the TM choke, and that didn't work, I used the power cord that was sent, just in case the original one was different--didn't fix it either.

Those ferrite rings are for the cables with an Interlink set-up also.

The unit I had RF interfenence with is the 798ci SI and only got the interference when using Side Imaging 455 khz.

The RF interference is a random occurrence with any model and make of trolling motor and the remedy is varied. Some remedies cause even more interfence such as the one suggesting adding a wire between the trolling motor negative and the unit power supply battery negative--that made mine worse

After you install your chokes and it doesn't take care of it, send me a PM and I have a bunch of other things to try.

[pantherdev]

I had my hopes up for this fix kit.  Will take a pic too when installed.  I find it hard to believe that two Johnson Outdoor products would not work together.