Radar inoperative

[furhelp]

Having worked perfectly for last four years suddenly my radar is not working. All I get is an echo as attached pic. Any suggestions?

 

[Johnny Electron]

Reduce the complexities and take a photo of a straight radar screen without overlay and other items on. That might help us put you into the right direction.

 

[furhelp]

Pics attached show range at six miles on radar screen and auto gain....nothing. At time less than three miles form very high cliffs.

Zoomed out to 48 or 72 miles and 100% gain I get a sweep, black lines but no shore which is about three miles away, cliffs.

 

[Johnny Electron]

I would have turned it to AUTO gain, AUTO clutter, Manual zero rain with all databoxes, AIS, and other overlay items off. No special things like echo stretch or echo trails should be turned On. All that stuff off and then see what it looks like. It almost acts like you have water in your antenna or you have something mounted near the radar causing serious reflections. Do you have photos of the radar installation both up close and of the overall boat?

 

[furhelp]

Hi. Tried that. Blank screen, not even the scan lines if before.

 

[Johnny Electron]

That big metal mast and rigging is a big problem for radar energy. You can't just bounce a ton of RF off that and then not get it screaming right back into the radar receiver. Whomever installed that should have put in sector blanking to prevent the radar from transmitting into all that metal. Radar will not see through metal anyway so why do that. Doing so only has negative effects. The radar has most likely tuned itself way down and plugging it's ears because of it getting screaming returns from metal inches away. I would recommend factory resetting the radar scanner while the radar is in standby, then inserting the proper sector blanking area to prevent transmitting into all that metal. Then try it with Auto Gain,, Auto Clutter, and Manual zero rain.

 

[colemj]

Johnny, I think you are off on that response. His is a very common setup for sailboats, and I've never heard of having to blank out the rear sector for a mast. The mast is well within the main bang area where the receiver should be turned off during transmit, so should not be an issue with a mast behind it. His mast is only 25% of the scanner length, so the transmission energy shouldn't be an issue. Granted, there will still be a small blind spot in the rear, but this is always the tradeoff with a sailboat mast mount. The OP stated that his radar was working perfectly for 4 years until recently. Furuno shows mast mounting just like his in all of their manuals.

I'm by no means a radar expert, and you certainly are more than me, but I found your answer didn't take into account the OP's entire issue. Particularly that it has worked fine for 4 years.

Mark

 

[Johnny Electron]

RF reflections on digital radar reacts different than analog processed radars. I would agree if this was a VX2 but its not. Setting the sectors takes a few seconds to try as does the reset. If it doesn't work, then it is time for a dealer to look at it or send it in for evaluation.

 

[furhelp]

Thanks but it ignores fact that radar has worked fine for last four years.

 

[Johnny Electron]

Sector blanking is a feature for a reason. Radar can't see through a metal mast and all that rigging so why the desire to blast strong RF back into the radar? It is very possible the mic got damaged due to all that time of being blasted. It is time to have someone put it on a work bench and check it out. I am sure they will get you fixed up.