First radar installation issues

[WillieC]

Having been caught out and limited by fog once too many times last season we have decided to install radar on the WillieC

I have landed on a Garmin 18xHD radome that will display on our fairly new Garmin GPSMap 741 plotter. (I can upsize later so not asking about this.)

I will also be installing a heading sensor as recommended (required?). This will necessitate installing a brand new N2K backbone/harness so the sensor properly communicates with the other components.

All this is being incorporated into fixing the BC hardtop issues I have bemoaned elsewhere, perhaps including new canvas. This is why I am not waiting until May to start this project.

A couple questions:

The cables for the radome come long enough for a Washington State Ferry so I may be shortening them. Any issues here, besides the supposed voiding of the warranty? I will be using the waterproof official Garmin cable end for the RJ45 and having my IT BIL do the crimp. I will also leave inline the original fuse in the power cable even though it will get a dedicated fuse slot in the panel.

Do I need a separate dash mounted switch to control the radome? Or does the software in the GPSMap plotter control whether or not radar is "on"?

Same question for the N2K backbone. Does it need a power switch somewhere in its power feed? I have no parasitic loads onboard, other than the vhf. Only the vhf and the bilge pump are wired directly to the batts before The Master Switch. Even the plotter is after the switch so I suppose I could wire the backbone power supply to the same bus feeding the plotter. It would basically be energized whenever TMS is closed. Suggestions/comments?

I suppose I will have more questions later but thanks for looking.

[WillieC]

Maybe I need to at least heat up the N2K and maybe the heading sensor with the key in the run position? Via another relay and fuse block.

[Jkraft]

Do you have an electronics switch now that powers on your devices? I have a switch on my dash labeled electronics and when I turn that on it throws power to my VHF, GPS, Network Hub, NMEA network, and radar. You dont want your GPS or your Radar tied into a source that is constantly hot.

I personally would not cut the radar cable but would neatly tie it up in a roll and tuck it away. I would be afraid of messing it up and if you ever want to sell the unit down the road for some reason everyone always asks if the cable is still all together.

I have the 741 plotter and Garmin radome on my shamrock and I did not need a heading sensor. It gets its heading from the GPS. On the Albin we also did not have a heading sensor in the original network but when we added the Garmin autopilot we had to add a heading sensor to the network.

You can control whether the radar is on or off via the chart plotter. That being said, when you throw power to the radar you can hear it spin up and go through a start up sequence and then it will go into stand by. That bothered me on the Shamrock so I tied the radar into its own switch.

[WillieC]

Jkraft,

This is very helpful. I have a separate switch already installed which will work perfectly for this purpose. I may just leave the vhf as is since we often use it at anchor or dock to check weather forecasts. Wouldn't need the other devices energized for that.

Also interesting about the heading sensor. The info I am reading says you need the HS in order for MARPA to work. Which means the ability to track other vessels specifically.

A side note. I have read somewhere that with the Garmin system, if you install radar you lose AIS tracking. That is too short of a description and likely needs much qualification. The 741 as installed doesn't have AIS built into it so I have figured out how to get the VHF to send AIS info to the plotter via NMEA 0183, which was tricky enough to configure. But it works and I would like to keep that operation. (Does MARPA supplant AIS tracking? We do not broadcast AIS.) We are currently using the internal GPS antenna in the 741, though we have a roof mounted GPS antenna used on the previous plotter. In this upgrade project I am planning on removing the external GPS antenna. The internal antenna works just fine. (OK...I should think about redundancy...but, hey, this is an A25 with ONE engine...)

Thanks, Jkraft. I appreciate you sharing your experience.

[GSSeattle]

I will be installing radar as well, going with the Garmin Fantom 24. If you already have an autopilot, you can network it in via NMEA 0183 or N2K and get the heading data for MAPRA. If not, Garmin released a new N2K GPS antenna (24xd) that has a magnetic heading sensor built in(not robust enough for Autopilot, but says it supports radar chart overlay and MAPRA). Price isn't bad

https://www.garmin.com/en-US/p/684270

I have moved all of my electronics + N2K network power to a circuit breaker bus, after the battery switch:
https://www.bluesea.com/products/5054/S ... gative_Bus

[GSSeattle]

Also, careful putting all the electronics on one dash switch - most switches are rated for 10 amps, some 15. Most electronics don't draw much, but can add up.

[WillieC]

Thank you, Greg.
There won’t be much on the electronics bus.
Good point about AP.

[WillieC]

On a related note...btw, the hardtop reno and radar install is slightly stalled, recovering from minor surgery and ten feet of snow, seems like...

With the freezing cold, we are considering installing a SIG 100 or eq. Dickinson, drip carburetor type heater. The issue, since we will now have radar, is the flue!

The only semi-logical place to put the heater, unless there are better options which I will discuss later, maybe start a new thread, is at the hanging closet. I would move the door to the forward facing wall of the closet, leaving me a flat, central wall to hang the heater on, just to the left of the head door. Thus, the four foot minimum three inch diameter flue pipe and radar friendly (NOT) end cap, would poke out right in from of the radome. Brilliant planning!

Plan B, is to sacrifice galley counter space and figure out how to hang the heater to the port side of the passageway door. This puts the flue off to port of the radome, which shadow seems less critical. Launch is still a ways out. Just pondering.

I like the fancy cooktop surface diesel heaters, but, yeah, no.

So, staying on topic, how dumb is it to put a flue in front of the radome?

[dkirsop]

At least two members of the BC Albineers have the type of heater you are considering. One is Var Bat and I think the other is Skol if you want to post a query to their site.

[DesertAlbin736]

About fog: At anchor in fog off Sidney Spit, BC. July 7, 2019. Having radar would have been nice!

DSCN4839.JPG

About heater chimney: Eileen's "Selkie", Wallace Island, BC July 11, 2019. Heater in the cockpit, apparently where cooler/fridge usually goes, chimney up through the BC hardtop. Radar dome istallation looks similar to what you're thinking of. Seen here on a chance meeting at the Wallace Island dock a day before the 2019 Albineer rendezvous at Ladysmith.

20190711_155725.jpg

We were all there at the rendezvous. That was very impressive that you made the effort to drive all the way up from Seattle & took the ferry over just to attend the rendezvous. That's dedication! We're hoping to return this summer, fingers crossed the US-Canada border stays open.

20190713_191659.jpg

[WillieC]

I have posted to our BCAlbineer friends and hope to hear back.
Selkie's set up looks interesting. Looks like the heater is mounted on the bulkhead where most of our groceries hang in a cabinet. More to follow, I'm sure.

Hmm. Upon closer inspection I see that you are correct, Steve. If you blow up the picture, you can see the angled stove pipe vent coming from the location you describe. I am thinking we want the heater in the vee-berth/galley area, thinking that if we install it in the cockpit area, it would not heat the galley very well. These things throw a lot of heat, so I could be wrong. Since I have completely re-worked the original icebox location to house our Pelican cooler, I am reluctant to re-do all that...but I still have the tablesaw. Now if I could just find another spot for it... Good suggestion, Steve. More to ponder.

[dkirsop]

Here are photos of the chimneys on Var Bat and Pagurus. Looks to me like they may have similar installations.

VÄR BÄT.jpeg

Pagurus @ Ladysmith.jpeg

[WillieC]

I was expecting the flues to rise much higher. Now I wonder how they draw or whether they are using the power draft. I have posted to the Albineers. It's been too long since we've been up there.

Thanks for the pics. I need to go back and review my pics of Ladysmith.

[WillieC]

Uhh...As noted earlier, this is our first experience with radar.

Yesterday, the Starfleet Commander asked if stowing the dinghy on the hardtop would obscure the radar view aft. I am mounting the dome on a 6 inch riser and there is a high probability that our cheap PVC dink could obstruct it, certainly in the human visible spectrum.

Will the radar shoot right through it, think four layers and an odd metal d-ring or two?

No shaming here. I do that well enough by myself.

[WillieC]

Shiny new paint on hardtop re- installed on boat.
I was able to fish the power cable to the radome in the original Albin raceway embedded in the ceiling frame. Plus horn wiring and a spare pull wire if I forgot anything. The cat 5 cable shares the hole in the ceiling with the power circuits then ducks out and above the new wood ceiling. I jammed a big coil of extra length in the void up there.

F9236BAD-746D-4397-97A8-88CDEC9B81CC.jpeg

You can just make out the cat 5 radar cable where it ducks in and back out the new ceiling.