Fish finder questions

[Douglasdzaster]

While rewiring everything I suddenly have some new stuff to add. I am finishing up the install of a new Garmin striker 4. I ran all the new wiring on the other side of the boat just for this. No interference. While I still had to get from where the Garmin is mounted on the gun wall back to the transom with the transducer and it’s electrical wires. I ran them parallel but about a foot or so apart. The battery is located in the last bench in a box same side along with new switch panel and fuse block. The transducer cable is up just under the top of the gun wall which gives me a good space from everything. I just don’t know how far it should be not to create interference. If I go up high with it all the way to the transom it’s going to pass right under the anchor light and a led flood light. If I drop it down back there it puts it close to the bench again. Would the fact that everything is inside the bench help any? I haven’t finished installing everything yet so I could move the battery , switch panel and fuse block to the other side. Only problem with that is I’m left handed and drive the tiller from the starboard side and wouldn’t be able to reach the switches if I needed to. Can anyone educate me more about electrostatic interface? And when the anchor light and flood light is switched off will it still interfere? I mean the anchor light is led and draws very little current anyway. The led flood lights are mostly for loading the boat.
One other possible problem with the fish finder is where my stern saver pad is located. When I installed it I set it up for a Lowrance I had. The Garmin transducer mount is different which puts the mounting pad a little low. I mounted the transducer almost to the top of the pad and set it up as high as I could get it but the transducer is running 1/4” to 1/2” to low below the bottom of the boat. This is going by a 10mm measurement I used for where I wanted it to be. Am I going to have problems? As of now I figured I make a test run and try to adjust the tilt of the transducer to see if I can dial it in.
I don’t know how to begin to get the old Stern saver off other than dynamite Or I would consider replacing it. I was sitting out there earlier with a cutting board measuring so I could paint it and use it over the pad except give it a little more heigh. I stopped myself because I didn’t do all the work I’ve done on this boat to start making it look cheesy. I’m big on DIY but I like to make things look as neat as possible. I’m building my own rod holder rack for the stern and it’s going to be removable but it’ll look as good as a lot of the ones I see for sale. Maybe not the high end ones but neat and tidy.
If I could get some help with this sonar I would greatly appreciate it so I can tidy it up and start on the next thing. I stopped pulling wire until I figure out if the extra lighting I want is legal on the water in Texas.
Man I’m tired. If I disappear from the site it’s because my wife found out how much I’m spending. And I’m living in my boat without internet.

 

[LDUBS]

Oops

 

[LDUBS]

I zip tied my transducer cable right along the cable/conductor bundle running under the gunnel from my outboard & battery to the steering console. I did try to zip tie it alongside the steering/shift cables as opposed to the electrical wires. But in reality they are not really separated. I took that route because I really didn't have another acceptable choice. If there is any interference happening, I sure don't notice. BTW, I ran a separate dedicated circuit from the battery to the FF.

Garmin has a support page on what causes interference. If I did it correctly, this link will take you there:

What Causes Sonar Interference? - Garmin Customer Supporthttps://support.garmin.com › en-US

You could take the boat out and do a dry run with the transducer cable running loose & away from possible interference sources. Then run it along the gunnel with the other conductors. Compare the before and after views. If you don't notice any difference, then bob's your uncle.

Regarding the transducer mounting position, I think 1/2" too low is, well, too low. They say the best way to remove the stern saver is to saw it off with a thin kerf handsaw. Personally, I would use my electric multi-tool. Use duct tape or something to protect the aluminum.

 

[user 26281]

Can anyone educate me more about electrostatic interface?

A simple explanation is when current flows throug a wire, EM fields are gernerated in all directions. These fields can be picked up by nearby wires through induction. All kinds of variables will determine the impact of the field induction on the other wires.

Also these fields can be picked up through conduction, like when all the positives and grounds are tied to the same battery.

For the most part on a boat, switching power supplies and electrical motors will generate the largest amount of interference.

Wire your boat the safest way, not the easiest way and you should not have any issues with EMI.

 

[Douglasdzaster]

I zip tied my transducer cable right along the cable/conductor bundle running under the gunnel from my outboard & battery to the steering console. I did try to zip tie it alongside the steering/shift cables as opposed to the electrical wires. But in reality they are not really separated. I took that route because I really didn't have another acceptable choice. If there is any interference happening, I sure don't notice. BTW, I ran a separate dedicated circuit from the battery to the FF.

Garmin has a support page on what causes interference. If I did it correctly, this link will take you there:

What Causes Sonar Interference? - Garmin Customer Supporthttps://support.garmin.com › en-US

You could take the boat out and do a dry run with the transducer cable running loose & away from possible interference sources. Then run it along the gunnel with the other conductors. Compare the before and after views. If you don't notice any difference, then bob's your uncle.

Regarding the transducer mounting position, I think 1/2" too low is, well, too low. They say the best way to remove the stern saver is to saw it off with a thin kerf handsaw. Personally, I would use my electric multi-tool. Use duct tape or something to protect the aluminum.

Hey thanks for the reply. I’ll do just that make some test runs before buttoning everything down. I’ve read and been in contact with Garmin. They’re the ones that told me to keep the transducer cable away from everything.
If I’m understanding you said not to use the fuse block for the power but straight to the battery? I was skipping the switch panel with it but that makes since too just go to the battery and use an inline fuse.
Ill remove the transducer and if I can’t figure anything else out I’ll get out the Dremel and remove the pad a piece at the time if I have to.
I appreciate you pointing me in the right direction and I’ll try the link and see if I can find more there.

 

[LDUBS]

If I’m understanding you said not to use the fuse block for the power but straight to the battery? I was skipping the switch panel with it but that makes since too just go to the battery and use an inline fuse

Well, I did say that. I read somewhere that it was a preferred method but I couldn't tell you where. I just took a look at my Hummingbird install manual. It says it is OK to use the fuse panel or a direct battery connection. Depends on your set up. My boat doesn't have a fuse block up under the console. Instead of splicing into a power supply under the console, I ran a wire direct from the battery fuse block to the FF. Here is a pic of the fuse block mounted on the battery terminal. Not saying this is the only or even best way. Just how I did it.

Ill remove the transducer and if I can’t figure anything else out I’ll get out the Dremel and remove the pad a piece at the time if I have to.

It really is too bad the stern saver is too small for your new transducer mount. How about screwing a correctly sized rectangular 1/8" thick alum plate to your existing stern saver. Then screw the transducer mount to the aluminum plate. I appreciate you wanting everything to look shipshape. Maybe this would work, IDK. Here is a side view of what I'm thinking:

 

[LDUBS]

A simple explanation is when current flows throug a wire, EM fields are gernerated in all directions. These fields can be picked up by nearby wires through induction. All kinds of variables will determine the impact of the field induction on the other wires.

Also these fields can be picked up through conduction, like when all the positives and grounds are tied to the same battery.

For the most part on a boat, switching power supplies and electrical motors will generate the largest amount of interference.

Wire your boat the safest way, not the easiest way and you should not have any issues with EMI.

I see "shielded wire looms". I wonder if something like that would address this issue of running a transducer cable alongside elect wires? It would seem to be such a common issue for just about every FF install that there ought to be a simple fix.

 

[user 26281]

I see "shielded wire looms". I wonder if something like that would address this issue of running a transducer cable alongside elect wires? It would seem to be such a common issue for just about every FF install that there ought to be a simple fix.

Pretty sure transducer cables are shielded, but not 100%. Some FF come with ferrite beads for the transducer, it's important that they are installed

Wire shieldes, wire seperaton, and ferrite beads are a few ways to help prevent intreference. One issue with wire shields, is they need to be bonded to ground somewhere around 2.5 milli-ohms. But if you install them and it works your done.

 

[thill]

You have gotten some good information so far. I wouldn't be surprised if your system isn't already problem free from your description. The transom-saver pad might be an issue though. I've learned to always make those bigger than you think. Some of the new transducers are huge.

I've installed a lot of sonar units, and I have found only a few things that interfere with them badly:
1. A high power VHF unit tied to the same circuit (run separate circuit to fix)
2. Certain trolling motors tied to the same circuit (run separate circuit to fix)
3. Certain older point-type inboard engines if the transducer cable is run very close to them. (Changing to supressor type spark plugs may help if this happens)

Hope it works out fine for you.

 

[Douglasdzaster]

I zip tied my transducer cable right along the cable/conductor bundle running under the gunnel from my outboard & battery to the steering console. I did try to zip tie it alongside the steering/shift cables as opposed to the electrical wires. But in reality they are not really separated. I took that route because I really didn't have another acceptable choice. If there is any interference happening, I sure don't notice. BTW, I ran a separate dedicated circuit from the battery to the FF.

Garmin has a support page on what causes interference. If I did it correctly, this link will take you there:

What Causes Sonar Interference? - Garmin Customer Supporthttps://support.garmin.com › en-US

You could take the boat out and do a dry run with the transducer cable running loose & away from possible interference sources. Then run it along the gunnel with the other conductors. Compare the before and after views. If you don't notice any difference, then bob's your uncle.

Regarding the transducer mounting position, I think 1/2" too low is, well, too low. They say the best way to remove the stern saver is to saw it off with a thin kerf handsaw. Personally, I would use my electric multi-tool. Use duct tape or something to protect the aluminum.

Got a lot more information from that link than what I’ve been finding.

 

[Douglasdzaster]

Well, I did say that. I read somewhere that it was a preferred method but I couldn't tell you where. I just took a look at my Hummingbird install manual. It says it is OK to use the fuse panel or a direct battery connection. Depends on your set up. My boat doesn't have a fuse block up under the console. Instead of splicing into a power supply under the console, I ran a wire direct from the battery fuse block to the FF. Here is a pic of the fuse block mounted on the battery terminal. Not saying this is the only or even best way. Just how I did it.

View attachment 113547





It really is too bad the stern saver is too small for your new transducer mount. How about screwing a correctly sized rectangular 1/8" thick alum plate to your existing stern saver. Then screw the transducer mount to the aluminum plate. I appreciate you wanting everything to look shipshape. Maybe this would work, IDK. Here is a side view of what I'm thinking:


View attachment 113548

I’ve got aluminum I’ve been collecting. I was fabricating bases for the new bilge pump and float switch today. I was using 1/16”. I’ll grab my caliper and see if I don’t have some 1/8” if not I can guy a piece of flat stock.
I removed the transducer today and was able to drill holes above those right at the bevel of the stern save with plenty of meat to screw into. I wasn’t able to see if it helped because I had just put 5200 in all the other holes. I’m thinking the aluminum will be way mo sturdy than having most of the transducer bracket sticking above the stern saver with no support.
And since I haven’t installed all the new stuff yet I think I’ll go ahead and move all the electrical to the other side. I still maybe able to reach the switches when underway. Nothing I can’t live with so I can have everything working and performing it’s best safety.

 

[Douglasdzaster]

You have gotten some good information so far. I wouldn't be surprised if your system isn't already problem free from your description. The transom-saver pad might be an issue though. I've learned to always make those bigger than you think. Some of the new transducers are huge.

I've installed a lot of sonar units, and I have found only a few things that interfere with them badly:
1. A high power VHF unit tied to the same circuit (run separate circuit to fix)
2. Certain trolling motors tied to the same circuit (run separate circuit to fix)
3. Certain older point-type inboard engines if the transducer cable is run very close to them. (Changing to supressor type spark plugs may help if this happens)

Hope it works out fine for you.

I think I got it figured out. I just want to do everything so it all works to it’s best safely. LDUBS gave my an idea he had . I can attach a thick enough piece of aluminum to the stern pad and make the extra area I need. I think I can make it look neatly done with a little paint. When this is all done I will still need to paint the boat.:Lol. Gotta budget one thing at a time. I would have painted it first but I found corrosion from the wrong hardware on it then the more I looked at the wiring and studied what it’s supposed to be like. I was asking for trouble if I didn’t prioritize that now.

 

[Douglasdzaster]

I only found 2” flat bar in 1/8”. I cut and dressed up a piece that’s going to work for the transducer. The paint is curing now it should look pretty decent. I took the rest of the 1/8” and redid the mounts for the bilge pump and float switch. Primed and will finish painting tomorrow. Everything turned out great. Can’t wait to get the transducer lined up with that 10mm mark I have on a piece of angle.
I wanted to thank everyone for the information and the help. I still gotta ways to go. Hopefully it’ll all go as planned out. I’m going to go update my rebuild thread now.

 

[Douglasdzaster]

I’ve been reading about ferrite beads for the transducer cable. Supposed to just clip it on close to the connector by the chart plotter. They’re cheap as heck on Amazon. Only problem is there’s to many different types and knowing the correct one. I think I’m ok the way I’m running everything but hey why not?
Just checking to see if any of you more experienced than I fishermen ever heard of such a thing.

 

[Still Afloat]

The best way to deal with EMI/RFI issues is to eliminate it at the source. The better trolling motors controller use a speed control system that basically chops the DC power into a square wave. The frequency of the square wave determines the speed of the trolling motor. This is more efficient than than varying voltage to the motor and it provides better torque.

The nasty side effect of speed controllers is EMI and/or RFI. You can use Ferrite chokes to suppress these nasties but, it’s really a complex topic and I won’t pretend to be an expert. In general the snap on chokes are the easiest to use. The larger toroidal (doughnut) ferrites allow multiple turns of the wire and provide the best suppression.

I would tackle noise problems in this order:

1. Eliminate potential ground loops. Basically connect all negative wires to a common point, the fuse block. If your negatives are connected to multiple fuse blocks there should be a ground wire between the fuse blocks. Grounding to both the negative terminal and the boat frame or hull will increase the chance of ground loops.

2. Don’t route signal carrying wires close-to and parallel-to power wires. If you need to cross a power wire try to keep the wires perpendicular to each other.

3. Running the trolling motor on it own dedicated battery will eliminate many EMI problems. A smaller separate battery for the fish finder and accessories is a great plan. Plus you will still have accessories if the trolling batteries run low.

4. If using chokes, start at the noise source. For example, the power cable as close as possible to the trolling motor. Choking the motor wires inside the control head right after the speed control is ideal but, it may not be practical. All wires carrying current to and from the motor must pass through the same choke. Choking all control wires exiting the trolling motor head may be required. Use the same choke for all control wires, don’t run some through one choke and some through another. To work effectively the choke must see equal currents traveling in both directions.

5. Chokes can be be used on the fish finder power wires and transducer cables.

Buy chokes from reputable electronics suppliers. Mouser, Digikey, etc., not Amazon and fleabay.

Good luck.

 

[Douglasdzaster]

The best way to deal with EMI/RFI issues is to eliminate it at the source. The better trolling motors controller use a speed control system that basically chops the DC power into a square wave. The frequency of the square wave determines the speed of the trolling motor. This is more efficient than than varying voltage to the motor and it provides better torque.

The nasty side effect of speed controllers is EMI and/or RFI. You can use Ferrite chokes to suppress these nasties but, it’s really a complex topic and I won’t pretend to be an expert. In general the snap on chokes are the easiest to use. The larger toroidal (doughnut) ferrites allow multiple turns of the wire and provide the best suppression.

I would tackle noise problems in this order:

1. Eliminate potential ground loops. Basically connect all negative wires to a common point, the fuse block. If your negatives are connected to multiple fuse blocks there should be a ground wire between the fuse blocks. Grounding to both the negative terminal and the boat frame or hull will increase the chance of ground loops.

2. Don’t route signal carrying wires close-to and parallel-to power wires. If you need to cross a power wire try to keep the wires perpendicular to each other.

3. Running the trolling motor on it own dedicated battery will eliminate many EMI problems. A smaller separate battery for the fish finder and accessories is a great plan. Plus you will still have accessories if the trolling batteries run low.

4. If using chokes, start at the noise source. For example, the power cable as close as possible to the trolling motor. Choking the motor wires inside the control head right after the speed control is ideal but, it may not be practical. All wires carrying current to and from the motor must pass through the same choke. Choking all control wires exiting the trolling motor head may be required. Use the same choke for all control wires, don’t run some through one choke and some through another. To work effectively the choke must see equal currents traveling in both directions.

5. Chokes can be be used on the fish finder power wires and transducer cables.

Buy chokes from reputable electronics suppliers. Mouser, Digikey, etc., not Amazon and fleabay.

Good luck.

I really appreciate the reply and information. I currently have the trolling motor on its own battery on the bow. The Garmin is mounted half way down the boat on the port side. The power and transducer cable run toward the transom parallel but a foot a part .All other electrical wiring will be on the starboard side including battery,fuse block with ground terminals and switch panel in the bench. When the transducer cable gets to the transom there’s the stern light an led flood (only used at the ramp) and bilge pump. These wires are crossed at 90 degrees a few inches apart then transducer mounted on the transom. The Garmin power runs in a loom by the way into the bench front side up high straight to the battery with inline fuse just before battery. The other wires I mentioned run parallel but in the back of the bench to a switch panel and fuse block. The battery is small and everything is in the bench. That being said the units power on this route will either have to pass over the switch panel pretty close or cross three wires at a 90 degrees. Everything is marine grade 14 awg including spliced into to GARMIN so I could make this run. Everything is in wire looms and all connectors are marine grade heat shrink with extra heat shrink tubing over that. I’m making a pig tail w 14 awg and bullet connectors for the Garmin so I can remove the battery every time the boats not in use. Also a 8 awg maxi fuse from the battery to an 8 awg pig tail made from a new trolling motor plug then 8 awg to the fuse block. Everything, wire connectors and all are tinned copper.
This is the minimal exposure I can come up with for the Garmin. Do you have any ideas for rerouting? I’m trying to keep as much wire tucked away un exposed but I could do different for instance rune down the outside of the bench then put a hole with grommet where I need to.

 

[LDUBS]

Gosh, from the routing you describe, it sounds like you won't have an interference problem. But I'm on thin ice when it comes to this particular technical stuff.

 

[Still Afloat]

Sounds good to me too. Your initial post was one long paragraph and I didn’t read it all.

Are you actually experiencing interference? If not, you are probably good to go. If so, turn off everything except the fish finder. Then turn on each item until the noise reappears. At that point you can begin isolating the problem.

 

[thill]

I agree completely with the two posts above. Make sure you are actually having a problem before worrying too much.

You don't have to be in the water to test it out. Turn everything on while sitting on the trailer. Turn your trolling motor and radio on while watching the chartplotter/sonar. If no interference, your routing was successful. Then go fishing!

 

[Douglasdzaster]

Sounds good to me too. Your initial post was one long paragraph and I didn’t read it all.

Are you actually experiencing interference? If not, you are probably good to go. If so, turn off everything except the fish finder. Then turn on each item until the noise reappears. At that point you can begin isolating the problem.

Yea my apologies I tend to get long winded. Especially if I’m on a rant.
This is a rebuild but I’m close to hitting the water. I appreciate your process of elimination idea.