[CA] [CA11] RD418HD Antenna Not Rotating

[boilerfan1999]

I've got a 7 year old RD418HD radome (it says "HD Digital" on it) paired with a C120W of the same vintage on my sailboat.

About a week ago, after no recent electrical or electronic modifications, I started getting a "SCANNER STANDBY Antenna Not Rotating" message. A restart of the scanner... by selecting "Scanner off," waiting for the cool down, then selecting "Scanner on" on my MFD, reset the problem on multiple occasions.

Now the issue won't go away with a reset. The issue seems to be regardless of voltage level of my boat's batteries (ie. the issue is duplicated both during battery discharge and when the shore power charger is in absorption). The radar had worked fine several times since the most recent winter storage season.

Are there any user serviceable parts or actions I can take inside the radome, such as a drive belt replacement or cleaning, that I can do from a bosun's chair, or at least without shipping it somewhere?

Thanks!

[Chuck - Raymarine - Moderator]

Welcome to the Raymarine Forum boilerfan1999,

Outside of a failure within the radome's internal components, the reported symptom would most commonly have resulted from insufficient power. However, should the vessel have been connected to shore power, its batteries have been permitted to achieve full charge, and while still connected to shore power should the problem be duplicated, then power maybe ruled out. Before sending the radome to Raymarine’s Product Repair Center to be bench checked / serviced, it would be recommended that the radome's cover be removed, that the belt lifted from the motor's pulley, that the motor pulley be wiped clean, that the belt be wiped clean, and that the array's pulley be cleaned. After reassembly, the radome should be tested. Should the problem persist, then the radome should be serviced.

[boilerfan1999]

Thanks for the advice.

I finally had time and good weather to go up the mast. It appears a wire had been obstructing the antenna's rotation. I would call the wire a "shield" wire or "bonding" wire, located just inside the radome from where the external cable plugs in on the exterior. This shield wire had slight damage from the scratching, and scratch marks were visible on the bottom of the antenna as well in the corresponding location. The shield wire had a little black discoloration, almost like there had been arcing in that location, too.

Otherwise, the radome interior seemed to be in a very clean condition. The belt and pulleys were clean with no apparent flat spots.

After securing the shield wire out of the way with a cable tie while keeping it connected, the radar tests fine. I'm hoping the issue is resolved!

[Chuck - Raymarine - Moderator]

boilerfan1999,

While I can't be certain, the condition of the cable which you have reported is similar to that which may be encountered with a nearby lightning strike. It is recommended that the radome be sent to Raymarine’s Product Repair Center to be bench checked / serviced.

[boilerfan1999]

Yeah, I was afraid you were going to say that!

So far, there's no evidence anywhere else of a static discharge or lightning strike on the boat. The radome is super clean inside, with no pinholes or anything visible on the dome in or out. The only arcing evidence was where the shield wire contacted the antenna. The shield wire does have a few broken strands, too, at the contact point.

Thanks for your help.

[Chuck - Raymarine - Moderator]

You're welcome.