Radar cable splicing

jrd22 · #1 (**permalink**) 03-22-2008

I had to cut the radar cable when we were unstepping the mast in preparation to ship the boat(ran out of time to pull it from the helm station, truck was waiting). We will (hopefully) be rigging the boat within a month and I'm going over all the details (usually at about 3am) that need to be done. This one is bothering me because I think I have heard somewhere that it's not possible/recommended, or at least not easily done. I'm not sure if I have to buy and run a new cable or if I can splice the wires. Anyone have experience with this, I haven't called the Furuno dealer, don't trust their advice(long story). If I have to buy a new cable I think I will relocate the radar from the mast to a pole on the stern to get the weight lower and make it easier to service in the future. Thanks in advance.

John

RichardElliott · #2 (**permalink**) 03-22-2008

I cut the Furuno cable to avoid a large hole in the coachroof to take the plug. I installed a small junction box in the head near the ceiling to make the connections. The coax needs to be spliced and is very fragile. The fine wire is encased in plastic and it is very difficult to trim the plastic without breaking the wire. That said, I was happy with the installation.

jrd22 · #3 (**permalink**) 03-22-2008

Richard- did you run the coax to a terminal in the j-box or connect it directly with a crimp or solder? Thanks for the reply.

John

erps · #4 (**permalink**) 03-22-2008

I'm in the process of replacing a real old radar unit with a not so old radar unit. I had planned on cutting the cable and changing the end connector so I wouldn't have to replace the whole cable. Dang, they had a different number of wires in each cable so I figured I would end up replacing the cable after all.

jrd22 · #5 (**permalink**) 03-22-2008

Bummer Ray, they are pretty proud of those cables too. Sounds like I can splice it, sounds like there might be some fussing around with the coax. We have Paul at Canvasman working on the dodger and the upholstery, thanks for the lead.

John

camaraderie · #6 (**permalink**) 03-22-2008

I cut and spliced my Raymarine radar cable on my last boat and simply wired all the wires to a large terminal block rather than trying to join the individual wires. Never had a problem.

RichardElliott · #7 (**permalink**) 03-23-2008

For the Furuno LCD radar cable I connected all of the wires to junction box terminals except the coax. The coax was soldered in order to splice both the conducter and the braided wire shield. Good luck!

Stillraining · #8 (**permalink**) 03-23-2008

Mine had to be spliced for the same reason as yours...seems to work OK so far...Longevity is my concern with any splice...mine is right at the mizzen deck step in the weather..

Ray: By the way ...One of your videos looks almost professional...nice job

billyruffn · #9 (**permalink**) 03-23-2008

Like Cam I've 'rewired' our Furuno radar cable using a terminal block, including he coax -- it's worked flawlessly for 7 years. The junction box is of the waterproof variety and it's located in a very dry place in the boat. I've 'tinned' the ends of some of the very thin wires to make it easier to get a good contact. A small amount of solder on the end of the wire seems to add just enough bulk to get it to hold well under the screw in the terminal block.

hellosailor · #10 (**permalink**) 03-24-2008

John, I think most of the industry will tell you tht you must run a new cable but others will tell you they've made do with splices. You can always TRY a splice, if it doesn't work you buy a new cable. If this is coax cable? Have two new "male" fittings crimped on the cable ends and use a dual-female connector to join them. Not knowing that cable you have or what fittings they use...I'd guess this is $25-30 in fittings alone, from a prime source. Plus the correct crimping tool, the one from the auto parts store won't do it correctly. And then if the splice works, seal it with butyl (self-vulcanizing) tape.

It *is* possible to splice a coax cable with just a soldering gun, but that creates an "impedance bump" in the cable which may affect the signals. I wouldn't recommend it except as a "get home" repair but again, some folks swear by it. Either by crossing over the center core to the hacket (and vice versa) and using teflon tape to warp and insulate then, rebuilding the core separation (and finishing with butyl tape) or by literally joining the center wire, rebuilding the gap with teflon tape, and resoldering the braid over that. And again, finishing with butyl.

I'll get flack for even having mentioned it--just remember I'm not recommending you do it that way! A proper splice, or a new cable, would be the way to go.