Seven years ago I upgraded most of the electronics aboard Priorities, including installing a new Raymarine HD Digital Radar with a C120W multifunction display. Of course, eight years is quite a while for electronics, and my stuff looks so out of date compared to the fancy stuff I see now at the boat shows! Everything has worked well, though, until just this past season.
I was out sailing while the Tall Ships were sailing past Milwaukee (similar to what I wrote about three years ago). I was using the radar to find ships that had disappeared in the haze with hopes of getting some good photos of them underway. At one point, while motorsailing in some chop, I selected the radar to “Transmit” and got a “Scanner Not Rotating” message. No radar data displayed. By “rebooting” the radar, I was able to get data on one or two more occasions, but by the end of the day, the error message wouldn’t go away.
After consulting with a local professional installer and the postings on Raymarine’s online technical forum, I checked a few “easy” things that might contribute to the problem. Every electrical or data connection, especially those in the bilge and mast base area, were checked for corrosion… but all were excellent. I swapped in a new, generic ethernet crossover coupler, but still had the same error. I switched plugs on my display (there are two SeaTalk HS ports), but still nothing. I tried testing things when the shore power charger was in its absorption phase, when voltage was at its highest, but this also made no improvement.
Since none of the “easy” fixes made a difference, it was time for me to go up the mast and peek inside the radome. I was hoping there was a wire that had gotten loose that I could simply resecure, but I was prepared to remove the entire radome and send it in for service. I had hoped for a calm day in the fall since I didn’t want to be swinging around in a bosun’s chair while messing with expensive electronics, but ended up waiting until after haulout to do the work.
As my crew arrived at the boat, I turned on the display and radar one last time to demonstrate the problem to my crew. Of course, right away the radar started working again! D’oh!
I still figured it was likely a loose wire inside the radome had caused my earlier problems. In order for Priorities to fit in the slings of the crane during haulout, I have to remove the backstays. With a keel stepped mast, the mast won’t fall over, but it does shake a bunch. I hypothesized this mast shaking moved the loose wire out of the way of the antenna, allowing it to rotate once again. I assumed the wire could cause issues again in the future, so I went up the mast anyway to search for the loose wire and check it for damage.
Not wanting to get “nuked” by radiation, I turned off the power to the radar at the power panel before going up the mast.
The Raymarine RD418HD Digital Radome has Phillips head screws on the top of the radome that hold the top panel in place. Unscrewing them and removing the plastic top was easy, even while hanging in a bosun’s chair. There is a “leash” to tie the top in place if needed that I found neatly stowed inside the radome below the antenna, though I never felt the need to use it.
At first I didn’t see anything obviously wrong inside. Actually, I was amazed at how clean it was, considering it had been “outside” for seven years! There weren’t any obvious wires in the way, but since the radar had just operated a few minutes earlier, this wasn’t surprising. I carefully checked the drive belt for flat spots, dirt, or damage, and found none. I gently moved the antenna through its path of rotation, and heard a scraping sound as it passed near a wire. Hmm…
My radar is connected to the multifunction display via a proprietary radar cable that carries both power and data. This cable exits the mast just behind the radome, and plugs into the radome in the lower aft section. Viewing the plug fitting from inside the radome reveals two wires with white insulation, presumably one carrying 12v power and the other data/ethernet. Additionally, there’s an uninsulated “shield” type wire, which I assume has to do with bonding for electromagnetic interference reduction (note that I’m not an expert!).
This bonding or shield wire clearly was the culprit. Tiny scrape marks were visible on the bottom of the rotating antenna at the contact point, and a few strands of the shield wire were broken. Additionally, there were a few signs of arcing, with some black residue visible on the shield. I considered if this had been caused by a lightning strike or static discharge of some kind (the Raymarine technician suggested this, too), but there have been no other issues with my electronics. I also didn’t find any signs of arcing anywhere else inside or outside the radome, other than at the contact point.
While the damage to the wire seemed minor, I still had a decision to make… secure the wire out of the way and say it’s “good,” or send the radome in for service?
While getting the radome serviced might seem like the “best” way to guarantee proper operation, there were risks with this option. The radome could get damaged during removal, during shipping in either direction, and during reinstallation with the mast still up. Servicing wouldn’t be free, either. It would also be a pain to have to go up the mast again in the spring while carrying the radome!
I chose the easiest path. I secured the wire clear of the antenna with a cable tie, and plan on monitoring things next season. I plan to see if running the radar causes interference with the VHF radio and/or AIS, in particular.
Of course, I’ll have to sail a bunch to do these tests… but I’m okay with doing lots of sailing!
I have a 2002 SL 70+ radar data problem is spring is antenna interior interior is not rotating. Radar screen itself lights up display looks normal. But antenna not rotating. Suggestions?
Like I said in my post, check for the easy stuff first, like electrical connections. If there’s anything interfering with the array’s rotation like I had, that could trigger the message. Also check the drive belt, which is likely a wear item. Otherwise, contact Raymarine Technical Support or your local tech. Good luck!