Splicing radar cable

[mlydon]

I recently purchased a raymarine digital dish to tie into my e7. I intend to mount it on my mizzen, and would like some sort of disconnect at the base of the mast rather than unpull 20ft of cable every time I drop the mast. Anyone have experience here?

How many conductors are there?
Are the conductors sensitive to,distance/patches?
Could I get away with basic mast connectors? (Aqua signal makes a nice 5-conductor one)

Thanks,

Matt

[sww914]

Ours is older, a monochrome display, but I doubt that the information carried by the cable is very different. Ours had 9-10 very small wires, a very small coax, 2 bigger wires and a bunch of shielding. The DAPO had cut it at the base of the mast and I tried to splice it with zero success. I am skilled and was quite careful. I bought a new cable and all was well. I can't say that I'd recommend splicing it.

[donradcliffe]

Use the search function and find several long threads on splicing radar cables.

[goboatingnow]

most of these are just ethernet cables now.

dave

[CaptTom]

The older radomes had a dozen or two various wires of different diameters. Some are twisted, some are shielded.

I've successfully spliced and re-soldered them on a couple of occasions and they've been pretty reliable.

[S/V Alchemy]

I would suggest experimenting with a properly sized terminal block.

[SailFastTri]

Originally Posted by S/V Alchemy

I would suggest experimenting with a properly sized terminal block.

I agree, and use a watertight pass-through at the deck. If your terminal block is situated beneath the ceiling liner it will stay dry -- very important for this sensitive connection. Leave a drip loop before the termination in case you get any leakage. The slightest bit of corrosion or oxidation will cause flakey operation. Keep your leads as short as possible. Keep twisted pairs twisted as far as possible (before separating for termination) and locate them on adjacent screws in the terminal block to allow for this.

The newer digital radars are high frequency signals at 5v. Bundled in the cable will likely be some twisted pairs of small-gauge wires to carry Ethernet, and heavier wires to control/power the spinning antenna and power and ground. If RF is an issue you can put the terminal block inside a metal box and attach the shield to the box, but I haven't found this to be needed in my Lowrance Broadband Radar system.

[Roy M]

It's not a problem, I've done it on ALL my radar installations on sailboats because, well, they're sailboats. You occasionally have to remove the mast, don't you? I first did it when I couldn't get an expensive Raymarine cross-over fitting. You just connect the cable to the corresponding wire of the cross-over fitting (confirm it with an ohm meter). On the other brands, just think of it as a mere extension of the color code. If you still have issues, after retwisting the wires, wrap the bundle with aluminum foil, in contact with the cable braid, and seal it. I've never actually had to go that far, though. In fact, I prefer either male-female spade connectors or a terminal strip near the mast. With NMEA 2000, it's even easier.

[Cheechako]

The olds ones were easy, just add a terminal strip under the floor in the bilge. I had no problem with theis several times. The new radars are entirely different though right? little dinky computer type wires?

[SailFastTri]

Originally Posted by Roy M

It's not a problem, I've done it on ALL my radar installations on sailboats because, well, they're sailboats. You occasionally have to remove the mast, don't you? I first did it when I couldn't get an expensive Raymarine cross-over fitting. You just connect the cable to the corresponding wire of the cross-over fitting (confirm it with an ohm meter). On the other brands, just think of it as a mere extension of the color code. If you still have issues, after retwisting the wires, wrap the bundle with aluminum foil, in contact with the cable braid, and seal it. I've never actually had to go that far, though. In fact, I prefer either male-female spade connectors or a terminal strip near the mast. With NMEA 2000, it's even easier.

Agree with what you wrote except to be specific, twisted pairs must be left as twisted pairs as much as possible. It does no good to twist the entire bundle if the individual wires run parallel to each other.