Radome Pole Installation

When we bought our boat, it had a dead Furuno radar. When we took delivery, we got a good deal on a Raymarine C70 display plus radome thanks to a kind soul letting us use their Port Supply account. The C70 replaces the radar, and augments the existing, older GPS units with chartplotter capability, plus lots of other cool features. Our plan was to securely, but temporarily, mount it for the delivery - then permanently mount it all later.

As these things seem to go, the temporary mounting plan didn't work so well - the new radome is quite a bit larger than the old one, and wouldn't fit in the same place up the mast (later Privilege 39's appear to have a large area between jumper stays for bigger radomes). So anyway, the whole thing, radome and display, went back home in the car, to be mounted later. Scott still thinks we should have mounted the radome on the top of the car - that would have been pretty funny on I-5.

In early 2008 we mounted the display, and integrated it with all the existing nav equipment (GPS, Autopilot, Wind sensors, etc) - but we still didn't mount the radome, since we still hadn't figured out quite how we were going to do so. The C70 is useful without radar - as a chartplotter and nav data display. And around the bay there's no real need for radar anyway.

For over a year we've debated whether the radome should go up the mast, or on a pole at the stern. Up the mast is a nice clean install, and gives the best radar range - but involves disassembling bulkheads and walls to route the cable, plus we'd have to buy an extension, or cut the current one and resolder it - tricky, as the cable includes a coaxial connection. Then we'd have to engineer a mounting solution where it could fit, or buy a mounting bracket and put it in a different location - then hang out on a bosun's chair 20' above the deck installing it. A pole is a relatively expensive option, and not quite as secure a mount - but is a much easier install. In fact, you can do it in about a day!

After looking around at different systems, and contemplating designing our own, we went with the SeaView 3" aluminum pole system from PYI. There were some tricky bits, but overall installation went pretty smooth. PYI is great to work with (Fred, thanks for helping us out!). We had a bit of a snafu with the trucking company (the poles are too big to ship via a regular parcel delivery), when they sent our pole off to Salinas on the wrong truck. It took them a couple of days to finally get it delivered. None of that is PYI's fault, and it really didn't matter except for staying home from work twice for deliveries that never showed up. Yep, typical boat project, something will not go according to plan, and - well, you just have to plan for such things!

Inside the radome. Ever wonder what's inside one of these things? Well we didn't have a choice, since installation requires some disassembly of the unit to get to where the wiring connects. This model is the Raymarine 2kw (RD218) - this is a basic analog scanner, not one of the new digital/HD types.

This is the swiveling base mount for the pole, and backing place - a piece of .190 aluminum from the metal scrap place around the corner. Yes, the holes are not square to the plate on purpose - anyone who's done this sort of a project on a boat already knows why - nothing is square and you have work around everything else. We put nylon washers between the aluminum plate and the stainless mounting hardware to help retard electrolysis of the plate.

This is the top plate for the pole which the radome mounts to. You can get all sorts of additional options that mount to it, light poles, antennas, etc.

Here we've got the base mounted to the hole, and the cable run though, ready to put the pole up. All hardware was bedded with 3M 4000UV. Remembering to run the wire through all the right places is a bit tricky. For example if we'd forgotten the white ring you can see in this picture, we'd have had to disassemble the whole thing again (we didn't fortunately!).

After running the cable through the pole, now it's time to mount the radome to the top. Note how we disassembled the top plate (shown assembled in a previous picture), to make it easier to fish the cable through. Once ready, the pole was drilled - you can see the holes the mounting hardware goes through. Per the instructions, we put a film of 3M 4000UV between the pole and the top plate.

Next, the radome is bolted on, wired, and the cover put back. We had a bit of an issue between the hardware (from Raymarine) and the plate (from PYI). The washers were not quite big enough and as we tightened the bolts, the washers started to cut through the plastic plate. Some bigger washers rectified the problem. The bolts are installed with some grease to prevent corrosion. Raymarine says to remove and reinstall the bolts yearly and regrease them. Does anyone actually do that? Didn't think so!

Nearing completion. Pole is up and temporarily in place, prior to getting it leveled (you can see it leans to starboard). The rail mounts have turnbuckles, making it relatively easy to level - as easy as it is to level anything on a boat! After getting it aligned, we had to drill some more holes and attach hardware. Note how the pole is very much outboard. With our long boom, we don't have a choice but to mount it so far to the side, even though Raymarine recommends against doing so. However, since the display is at the helm, right below the pole, this should give a bit more accuracy in relative bearings anyway.

Completed assembly! Pole is aligned and leveled, and the strut has been attached. We still have some 3M 4000UV to clean up where the base for the strut was bedded to the hull. That stuff is sticky and gets all over everything - Scott always manages to get it everywhere - all over his hands, clothes, everything he touches, and even sometimes on what ever it is that's supposed to be bedded. You can't wash it off with water, either - water just spreads it around.

Finished base, with final caulking (3M 4000UV again) and the cable gland installed. One of the most difficult parts of the project was installing the bolts between the pole and the base (which you can see near the bottom of the white part of the pole). While the pole is 3" in diameter, there's a lip on the base reducing that by about 1", plus the thick cable running through. Reaching up to install the nuts, without dropping them where they'd fall right off into the water was a pain. Fortunately Chris has small fingers and was able to reach up and get the nuts on. There was no angle to get a wrench on the nuts either, so Scott finally figured out the best way is to just shove the whole wrench up inside the pole, getting the box end around the nut and letting the wrench stand up inside the pole. Getting the wrench out again was fun too, but we got it all done and secure! It would have been possible to do this step earlier, before bedding the base to the hull, but we wanted to be sure to get the radome bearing correct, which we couldn't guarantee otherwise that it would be pointing straight ahead.

A nice view of the 4 bolts that we're supposed to remove, grease, and reinstall yearly (yeah, right). Man, that thing is way up there... Our pole is 12' high, roughly 15' off the water, and will give us a range of roughly 9-12nm for boats. PYI measures the pole based on assembled height, so the pole itself was 11'3" - with the base and top plate making up the difference (and then some).

Radar display (sorry, display looks purple from glare, bad angle). Too much noise from boats, trailers, buildings, etc in the marina to do final calibration - that will have to wait until the next time we go sailing. It's always nice to complete a project, and this one was relatively complex, and a long time coming!

We have nothing but good things to say about PYI - call Fred Hutchison at 425-355-3669 or 800-523-7558 and let him know we sent you his way. Fred's great to work with and makes everything happen fast with no hassle. We have a couple of other PYI products aboard as well, and they make some shiny, well engineered stuff.

Perhaps the most amazing thing about this whole project is we only had to go to West Marine ONCE for parts! Usually we end up going either there or the hardware store at least 2 or 3 times. All we needed was some fasteners for the base and strut plates, and a tube of 3M 4000UV. Speaking of that, why don't they make smaller tubes of this stuff, as well as 4200 and 5200? Once you open the tube it will all set up, and most of the time the small tube is way too much (even with Scott's penchant to only get about 1/2 of it on whatever he's trying to seal and adhere), not to mention $13.

Our navigational electronics are now nearly complete - with everything integrated and working with onboard systems as well as with OpenCPN. The only other planned upgrade will be an AIS receiver, which everything is already wired for, all we need to do is hook one up, as the NMEA MUX already has a port for it, and the C70 as well as OpenCPN already supports AIS. We probably will not buy an AIS transponder in the near future - maybe in a few years, once there's better adoption and commercial ships start actually paying attention to Class B collision alarms.

1 comment:

  1. Dang what a project - at least you have another lightning rod


Click here to buy Jane'O merchandise