Furuno Fan
The NN3D MFDs are designed to connect directly to the UHD DRS scanners for simple installations, with the power provided to one half of the "Siamese" cable through a waterproof connection to the back of the MFD, and the ethernet connection provided through the other half. Unfortunately this other half of the cable does not have a waterproof plug on the end, so just connecting directly to the MFD is an invitation to corrosion. The not-very-good solution is to use the ethernet cable provided with the MFD, which has a waterproof connection on one end for attachment to the MFD. The other end must be connected to the radar cable with a non-waterproof ethernet coupler, and a couple of meters of ethernet cable must be stored. Needless to say, this just moves the corrosion problem from the back of the MFD to somewhere further up the cable, and adds a mess of cable.

It is clear that the current radar cable is intended for use with the (non-waterproof) hub. For the many customers that don't use a hub this is a bad design. The DRS radar cable should be available with a waterproof ethernet connector either as part of an alternate part number for the radar, or on exchange at time of purchase.

For my current situation, I would dearly like to get a new waterproof ethernet plug so that I could crimp it on the end of the existing radar cable (I am perfectly capable of doing this properly). Unfortunately, this plug is not available from Furuno, at least as far as I have been able to determine. At a minimum I would like to be able to order this part, but gifts are welcomed. :D As a last resort I might just cut the waterproof plug off the existing cable and try to fit it with a new shielded plug. But I would prefer not to do this.

Hi Greg,
Most installations do require the use of a HUB. Normally you would have an MFD display, a DRS radar, and a Digital BB sounder. With three or more networked products you could not use point to point connectivity, but would have to use a HUB. Most of these installations would not use the 8 port HUB101, but would use the BBWX2 Sirius weather receiver with a built in 5 port hub, and a IPX4 protection rating. In your case, only two network products, you are correct, you do not need a hub, you can use an RJ45 coupler. Personally, I would not cut the cables to install a waterproof connector and receptacle. I would simply use adhesive lined heat shrink to seal the coupler connection. One piece about 5 inches long will cover the coupler and the RJ45 connectors plugged into it. Unless you are planning on taking apart this connection fairly often, that is what I recommend. If you cut the cables to install aftermarket connectors you run the risk of improper crimps and the problems associated with that. Using an adhesive lined heat shrink is a simple solution and it works.

Best regards,
Yes, I could waterproof the ethernet coupler with coax seal and tape. That would be a bit messy, and I would still have a lot of excess cable to deal with.

Admittedly Furuno's market is mostly the fishing scene, commercial and recreational, that wants both radar and fish-finding. Still there are a lot of us cruising sailors buying Furuno radars; it might be wise to make a small effort to polish the offerings for us. I consider offering such a cable a pretty small thing, and the lack of it a nuisance. Ultimately it is a business decision - I'll leave it to the product manager to decide to appeal to us, assuming he gets this.

I agree that many customers would do an inadequate job of crimping, thus causing themselves problems. I will gladly take the responsibility upon myself.