texasfishingforum.com logo
Main Menu
Advertisement
Affiliates
Advertisement
Newest Members
ItekTackle, Sabre, crazylop, Sun up till Sun down, John Gray
111009 Registered Users
Top Posters(All Time)
TexDawg 91,409
hopalong 81,121
Pilothawk 78,481
John175☮ 72,362
JDavis7873® 67,395
Derek 🐝 62,651
Tritonman 58,722
Bigbob_FTW 57,768
Mark Perry 56,221
facebook
Forum Statistics
Forums60
Topics756,920
Posts9,504,435
Members111,009
Most Online36,273
Jan 23rd, 2013
Print Thread
Electrical noise on a fish finder #13244816 08/12/19 03:07 PM
Joined: Apr 2006
Posts: 45
L
lschmidt Offline OP
Outdoorsman
OP Offline
Outdoorsman
L
Joined: Apr 2006
Posts: 45
I have had some issues with a fish finder getting feedback and interference. Only the one in the front gets noise. There are two times it happens. When i hit the trolling motor and sometimes a more random occurrence.

I expect that the trolling motor is older and just not shielded well (has the transducer clamped to it). The random issue shows a repeating pattern of a short bar of noise every couple of seconds, but doesnt happen all of the time.

The only thing that seems to stand out is the power switch to the live-well pumps goes through resistors (NTE5800) and one of them appears to have overheated in the past (before it gets to the time delay device).

Any suggestions for things to check would be appreciated.

Bass Fishing Ad
Re: Electrical noise on a fish finder [Re: lschmidt] #13245012 08/12/19 05:34 PM
Joined: Jan 2017
Posts: 893
S
Shallow Waters Online Content
Pro Angler
Online Content
Pro Angler
S
Joined: Jan 2017
Posts: 893
Next time you go out disconnect the electronics battery from your on board charger and see if you are still having issues. More often than not there is a diode in the charger that goes out and allows talk between terminals.

Next option is to wrap your trans cable through a terroid and see if that helps. this would help determine if it is the actual trolling motor proximity.

Either way, you are in for potentially a long goose chase here. Took me 3 months to clear up mine, and it still shows up on occasion, especially in shallow water.

Re: Electrical noise on a fish finder [Re: lschmidt] #13245118 08/12/19 07:12 PM
Joined: Aug 2015
Posts: 2,954
P
Pintail711 Online Content
Extreme Angler
Online Content
Extreme Angler
P
Joined: Aug 2015
Posts: 2,954
NTE5800 is a diode.. diodes allow current to flow in one direction, basically a switch. So it could be possible that diode is allowing current to back feed. Cathode side, with the band, is negative polarity and anode side is positive. You said it’s burned so that’s where I’d start.

Re: Electrical noise on a fish finder [Re: lschmidt] #13246037 08/13/19 02:34 PM
Joined: Nov 2012
Posts: 552
B
Bill Durham Offline
Pro Angler
Offline
Pro Angler
B
Joined: Nov 2012
Posts: 552
This is one of those things that you can almost write a book about. You may already have things setup like this but first thing is you need to run the graph off of your cranking battery and not a trolling battery. Motorguide says you need to connect the negative battery posts of the crank battery and the first trolling battery (if you have a 24v system, the battery that the trolling motor negative connection is made to) to create a common ground for all of the accessories. I found some copper braid shield that I put over my bow finder power cable and connected that to the negative contact for the finder power. Keep the power cable for the finder as far away from the power for the TM that you can. The toroid core that was mentioned before is also a good option. I saw on one video a guy had drilled a hole in the skeg of his TM and attached a cable to that and run it up to the negative connection for the TM, grounding the case of the TM in the water. I haven't done the grounding the motor case and the toroid yet, but those are next for me.. good luck. its complicated!
BD

Re: Electrical noise on a fish finder [Re: lschmidt] #13246074 08/13/19 03:02 PM
Joined: Jan 2015
Posts: 49
V
vicstric Offline
Outdoorsman
Offline
Outdoorsman
V
Joined: Jan 2015
Posts: 49
Tell us about your fish finder? Brand? New? Older? Noise something new or been going on a while?

Re: Electrical noise on a fish finder [Re: lschmidt] #13246232 08/13/19 05:27 PM
Joined: Jul 2014
Posts: 3,819
B
Bobby Milam Online Content
TFF Team Angler
Online Content
TFF Team Angler
B
Joined: Jul 2014
Posts: 3,819
There are several options to try to eliminate it.
Does the TM have a fuse in the head? If so check it.
If you move the FF away from the TM does it stop? I moved mine to the right side of the deck and now have none.
Is your FF wired directly to the battery with it's own wire or wired into the boats wiring harness?

A youtube search will show you some other ways to fix it depending on which unit it is. If it is HB then contact them and they have a couple of things you can get to fix it.

Previous Thread
Index
Next Thread


© 1998-2019 OUTDOOR SITES NETWORK all rights reserved USA and Worldwide
Powered by UBB.threads™ PHP Forum Software 7.7.3