[204Angler]

I know that I've seen posts on this before; people asking whether you can do it and if so is it tough, how etc...
I had a lowrance with a transducer/power line that got smashed by the trolling motor while I still had my bass boat.

I just cut it, pulled back insulation and shielding, stripped wires back some, butt-spliced and did heat shrink all 5 connections with electrical tape over the whole mess. Functional tested good. Took me 20 minutes and I've got a finger with 10 stitches.
Just take note they are around 20-22 gauge wires so have the correct size splices. Cut back enough insulation and shielding you give yourself plenty of room to work, strip the wires, make your connections etc... Don't forget this is sensitive electronic equipment; try to leave your splice out of any areas it might be submerged or exposed a lot. If possible tie it up out of the bilge, sheltered from spray, rain etc...

By the way this will just go on my little plastic duck boat

Good luck!!

 

[trigger22]

Don't forget to repair your shielding. I'll splice just about anything and have the utmost confidence in it but that comes from a lot of on the job training

 

[204Angler]

Don't forget to repair your shielding. I'll splice just about anything and have the utmost confidence in it but that comes from a lot of on the job training

I didn't repair the shielding is that bad? It worked but will I see interference?

 

[trigger22]

Chances are you will see some interference. It's not hard to do the repair on it. If you aren't sure how I will do a demo tomorrow evening at work and send it to you. I'll actually be teaching it tomorrow anyways so it won't be any extra trouble

 

[OptiMystic]

The shielding on coax is important at my house because I am in the shadow of a large radio antenna. It keeps the inner wire from getting interference, but there has to be a nearby RFI source to interfere much. If you have a VHF radio, you might see weird stuff on the FF when you transmit if the cable isn't fully shielded. I am assuming we are talking about a small open patch and that you at least
connected the shielding back together.

 

[trigger22]

You'll also pick up noise from a motor without proper shielding for EMI protection.

 

[OptiMystic]

You'll also pick up noise from a motor without proper shielding for EMI protection.

DOH! Forgot about that. Spark plugs are the worst; they transmit on every frequency. Not very far, but serious bad noise nearby.

 

[trigger22]

Yeah I have fixed some crazy discrepancies caused by lack of or improper shielding. Another common mistake is someone will do a repair and not pay attention to their shielding and will have it shorted to the center conductor.

 

[204Angler]

Oh ok. So, the tin foil I ripped off and threw away will need to go back on? It was about a 3" length and it is on my 9' twin hull plastic boat with a bill dance 40# motor. No vhf, no gas burner... So, when you say have the shielding short to the center conductor do you mean that the paper isn't between the shielding and the bare strand wire? I know Ill have zero shorts but I also know I didn't put the shielding back

Trigger, If you don't mind that would be great posting that video.

 

[trigger22]

Yes I mean not to let the shield touch the actual wire itself. I will make a video tomorrow evening when I get to work demonstrating the basics of how to repair.

ETA that an electric motor will also cause interference with the signal. There's a very good chance that you won't notice any effects, but it very well could give you false readings or maybe it will have just enough insertion loss not to pick up a weak mark.

 

[204Angler]

Yes I mean not to let the shield touch the actual wire itself. I will make a video tomorrow evening when I get to work demonstrating the basics of how to repair.

ETA that an electric motor will also cause interference with the signal. There's a very good chance that you won't notice any effects, but it very well could give you false readings or maybe it will have just enough insertion loss not to pick up a weak mark.

Ok cool. Well...for myself and everyone else that needs it, thank you in advance for the video. I haven't place the transducer and FF yet so maybe I can put the spliced section as far to stern as possible, get it as far away from the trolling motor as possible.
My brother is coming to town and wants to bass fish and all I've got is my 25' Wellcraft and ski boat so I am quickly turning my duck boat into something we can fish out of. That means trolling motor moved up front, FF installed, 12v outlet, lights, live well...jeez! Duck hunting is so much easier

 

[204Angler]

The shielding on coax is important at my house because I am in the shadow of a large radio antenna. It keeps the inner wire from getting interference, but there has to be a nearby RFI source to interfere much. If you have a VHF radio, you might see weird stuff on the FF when you transmit if the cable isn't fully shielded. I am assuming we are talking about a small open patch and that you at least
connected the shielding back together.

.....Wish I could say yes

 

[trigger22]

I unfortunately was not able to get a video made of this as I forgot and had already sent my guys home by the time I remembered. I did however do a step by step and took pictures. I will do my best to describe what I am doing in each picture. The parts I was using are parts that we utilize to fix the aircraft at work. You can however find the similar materials at a radio shack.

First thing you need to do is trim back your wires. You want to remove about 3 inches of the outer jacket and leave about half an inch of the shielding. You will do this on both sections of wire. Once you have done that you can splice your wires. My example is with a wire that has 2 conductors and 1 shield. The same method will work with however many conductors you have. Once everything is stripped back you will need to splice your wires back together. It is a good idea to stagger your wires as best as possible to prevent having a giant bulging area in the middle.

. Now that your wires are spliced you need to shrink your heat shrink over the splices and prepare your shield to be installed. Notice I have left about half an inch on both ends to install the new shield over. The most preferred shielding is a "hollow" style shield that will slide over the wire. You could however also use a wire mesh shielding that will wrap tightly around the wires but it won't be as clean.

. I have my shielding prepared and am now going to install it. The two pieces that I am going to slide over the top of it are called solder sleeves. They have a small band of solder in the middle of them and when heated with a heat gun the solder melts as the sleeve shrinks and it bonds the new shielding with the old. You want these pieces to sit directly over the top of that half inch of original shield.

. Once in place you can go ahead and shrink them with the heat gun.

. After the solder sleeves are shrunk over the new shielding and mated with the original shielding you can now shrink down a piece of heat shrink over the entire job and you are finished.

. It is important to note that my demonstration is of a piece of wire that is not attached to anything. You will have to have everything installed over the wire before you ever do the first splice. If you do not, there won't be a way of getting your shrinks or solder sleeves installed and you will have to cut everything apart and start over. If anything at all is confusing or if you aren't sure about a step please don't hesitate to ask and I will clarify it for you.

 

[Drum Runner]

Good job!.........

 

[RouseD]

trigger, I don't think a book written on this could have explained it better. I used to do some of this work also. I learned a lot from this myself.

 

[trigger22]

Thank you, and in all honesty the manual that we have for doing this repair doesn't break it down in near as many words. It has a few words and some pictures with stripping dimensions. Then again, when it's your profession you should be able to look at a picture and replicate it.

 

[OptiMystic]

Outstanding! My attempts at splicing coax often end up involving connectors and a short extension if I can't give up any length plus a coat of thickened epoxy on the connectors if it is getting buried (TV cable in the yard).

 

[204Angler]

Wow thanks Trigger. Between that clear explanation and pictures I might even be able to do it now. I will make some time this weekend to redo what I did and I'll try to add pictures of mine since it is an actual transducer cable. When I do, I ask that you constructively criticize my work so others reading this thread can benefit.

 

[trigger22]

Outstanding! My attempts at splicing coax often end up involving connectors and a short extension if I can't give up any length plus a coat of thickened epoxy on the connectors if it is getting buried (TV cable in the yard).

Coax is a little different but not a whole lot. I can do one on that as well but have to say just in case big brother sees this that at work we are not allowed to splice coax. We can repair shielding or replace a connector but no splice. In combat well that's a different story and rules are a little more flexible. Either way, splicing coax is very easy. Again it is extremely important to take extra precautions not to short the center conductor to the shield and to be sure you have a good shield at the completion of the job. Sunday night I will coincidentally be teaching my students coax cable repair...

 

[trigger22]

Wow thanks Trigger. Between that clear explanation and pictures I might even be able to do it now. I will make some time this weekend to redo what I did and I'll try to add pictures of mine since it is an actual transducer cable. When I do, I ask that you constructively criticize my work so others reading this thread can benefit.

I have the utmost of confidence that you'll be able to pull it off. Good luck and if you need any help fire away.