Short in FF cable

Like it says above, I have a short in my Lowrance/Eagle ff cable. It seems to be within the first few inches of the end. I can get the thing to come on and stay on with some careful bending, but this is getting ridiculous.

 So can I just cut out the bad section and splice it back together and wrap it in heat shrink? Or does that wreck the impedance matching or some such foolishness? It'd be nice to shorten the cable and get rid of that bundle of wire that made for a bass boat, but I've read somewhere that's was not a good idea and that has me gun shy of cutting and splicing at all.  Anybody been there, done that?

i have never done it before...but if your cable is bad to start with you might as well try cutting it out and splicing it...

i have read plenty of posts of people claiming they have spliced ducer cable wires without having any problems...
i don't think i have ever read one that said it doesn't work...but everyone seems to be very freaked out about it

i've never really looked at a ducer cable though...is it twisted pair (i know i read about one somewhere that was 2 twisted pairs)
is it shielded wire? if so are the shields terminated at the ends?
Is it coax?
i've wondered if i could do this when i get mine cause i would like to put a single thru hull disconnect to make it easier to remove the unit from the topside...and not bother with wiring...of course on the other hand most of the ffs have disconnects that are fairly easy on the back

are u planning to crimp butt splices or raychems on...i would suggest raychem environmental splices if you are going to use crimps
or you could just solder them on which would probably be a better way

a quick google search and this is what i came up with on iboats.com

I've already replaced my transducer with a new one but, for your info and reading pleasure here's what they say.....Transducer Cable Splicing Instructions. Lowrance does not recommend cutting and slicing of transducer cables. The connector ends are injection molded onto the cables and the transducer body housings are potted with an epoxy material to make this accessory completely waterproof. Water infiltration in this cable can cause delaminating, internal corrosion, and cable damage, which can result in poor performance at the least - and sounder malfunction or damage at the worst. If a cable is cut or broken we do provide some accessory connectors which are preferable to splicing if the cable remains long enough to reach. However if the cable is too short or a connector kit does not exist then you should follow these instruction to splice the cable. This procedure is best performed by a reputable and skilled electronics repair facility or technician. Cut the cable in a location that will place the splice in a protected area in the vessel. It should not be exposed to rain or spray, nor be allowed to lay in the Bilge or other area which will allow it to be submerged in water. If using a “heat shrink” insulating material, for either the center conductor connection, shield connection, overall splice, or all of the above, place over the cut ends now.Carefully strip approximately 1” of the outer insulation or jacket from the ends to be spliced. Unwrap the shield and twist it as shown below.  Strip approximately 3/8” of the inner insulation (center conductor) from each end to be spliced. Twist the center conductors of the two ends together, then solder the connection. Use special care to allow full flow of solder without damaging or melting the insulator around the center conductors. This can result in a shorted connection and damage to the sounder. Wrap the solder joint in good quality electrical tape or heat shrink as appropriate.  Twist the shield wires together and solder this connection. Wrap a small piece of Aluminum Foil over the entire splice. Make certain the foil makes a good contact with the shield wires to prevent, reduce, or eliminate electrical noise or interference.  Finally wrap the entire splice with electrical tape or use the Heat shrink material previously installed to completely seal and insulate the splice connection. The transducer is now ready to use. If we can be of any further assistance please contact us. Lowrance Customer Service 12000 E. Skelly Dr. Tulsa, OK 74128 Customer Service: 1-800-324-1356

VERY COOL!!!!

Thanks yessnoo! That's not only permission, but blessing from on high no less! I was planning to solder it and from their description, it should be doable. Besides, it can't get much worse.
Poking around on the net I found a suggestion to run a separate power line and I may try some amalgam of that. It'd be nice not to have to cut the other wires that are not broken, but I'm a bit concerned about the opening in the shield. But before I cut them all I think I'll  kludge a wire from the battery. I'll post the results.

Wali

If that fails, I have a new spare you can have cheap.

My local RF guru tells me that most modern units don't rely on cable length to match impedence.  They used to do that when the signal was generated in the plotter and sent to the ducer but the modern units have the signal being generated, sent and recieved at the ducer itself.  The cable now just carries voltage from the plotter to the ducer and a digital signal from the ducer to the plotter.

Spend the extra time on waterproofing!  I've had to re-do mine and it sucks.  (Salt water will corrode the wires waaaay up inside the insullation) There's a product called "Liquid electrical tape" sold at ACE that you can put on over the heat shrink to ensure water proofedness....   

And if all else fails..... You can always buy a new cable  (~$40)

Good Luck!
-Mark-

If that fails, I have a new spare you can have cheap.

Done! Just tell me how much to send. I actually need another one for the other boat and one of them will get the bummy wire if it works.

My local RF guru tells me that most modern units don't rely on cable length to match impedence.  They used to do that when the signal was generated in the plotter and sent to the ducer but the modern units have the signal being generated, sent and recieved at the ducer itself.  The cable now just carries voltage from the plotter to the ducer and a digital signal from the ducer to the plotter.

Good Luck!
-Mark-

Mark, I was hoping that someone would chime in with something like that! Thanks!

How about putting a layer of black/gray automotive gasket maker over the entire surgery areas, allow to setup, then heat shrink tubing over that, and then seal that with the liquid tape?   Nothing should get through that!