Removing the radar tower

After literally YEARS of deliberation, we finally decided to remove the radar tower from the cockpit of Gimme Shelter. The aged JRC Radar 1000 still worked but was hard to read, and the tower support poles caused a major complication when it came to designing a new bimini.

wpid-20150301_151926.jpg

The entire process was relatively painless. I had to clip the plugs off the ends of the cables to slide them down through the helm, but once they were clear, I was able to just unbolt and lift out the pole.

RadarRemoval01

Then I had to mix up some thickened epoxy to fill the holes.

RadarRemoval02

I was extra careful to mask around the holes after I got in trouble for dripping epoxy on the gel coat while replacing the winches.

RadarRemoval03

The only tricky part was bending my arm down through a hole and back up into the transom to tape up the bottom of the big hole, but even that worked out.

RadarRemoval04

Next weekend I’ll have to add just a little more epoxy to the big hole to build it up even with the rest of the stern. Then we can sand everything smooth and gel coat back over the repairs.

When the budget allows we may eventually add a Garmin radar, but if we do we’ll use a self-leveling backstay mount that won’t take up a bunch of space. In the meantime, the cockpit is now clear for our new bimini project!

Installing a NMEA 2000 backbone

One of the things we liked about our new Garmin chartplotter that we installed in December was its connectivity.

DSC07547

The chartplotter was our first electronic device with a NMEA 2000 plug.

NMEA stands for National Marine Electronics Association, and 2000 is the standard set for communication between devices. Garmin sticks with a NMEA 2000 nomenclature, but Raymarine SeaTalk, Simrad Simnet, and Furuno CAN are all rebranded NMEA 2000 systems that only need a plug adapter to be compatible.

Theoretically, any two NMEA 2000 devices will connect and communicate with each other no matter the brand. However, since we’re starting from scratch when it comes to the electronics on Gimme Shelter, we decided to stick with Garmin as much as possible.

The first step to setting up any NMEA 2000 system is to install the backbone. We went with this Garmin NMEA 2000 Starter Kit that cost about $60 through eBay.

NMEAstarterkit

The only directions that came with this kit was the diagram on the label. That’s it. It’s THAT simple. However, I chose to hook the yellow cable, which is the 12 volt power cable, to the chartplotter circuit on the back of my breaker panel instead of directly to the battery.

DSC08069

Once it was tied into the power system, I started adding T connectors. (Note that there was terminator plugged into the open end of the backbone when I finally took the photo.)

Tconnectors

The starter kit came with two T connectors and two terminators. I ran a cable from one T to my chartplotter. I ran the other cable to my GWS 10 Wind Instrument.

GWS10

I switched the chartplotter to the “gauges” setting, chose wind, and … nothing.

Nothing happened at all. It didn’t work.

I stared at the diagram. I retraced my wiring. I pulled the breaker panel off again and re-checked my power connection. It just wasn’t doing anything.

I finally resorted to Google and almost immediately I found out the most important detail of this system.

NMEA 2000 doesn’t work unless there is a terminator on every open T plug!

The starter kit had come with two terminators, and I hadn’t bothered to put them on. I figured they were just to keep the dust out or something. Wrong. It turns out there’s a resistor in those terminators, and unless they’re on the open plugs, no signal gets sent anywhere.

So after plugging a terminator onto the end of the backbone, I turned on the chartplotter again. This time I had success!

windinstrument

Now all it takes to add new devices to my system is another T and a NMEA 2000 cable.

Of course, setting up the backbone was the easy part. The real fun starts this weekend when I climb the mast to drop a new cable and mount the wind instrument.