Unable to see some channel markers (TZT3 , DR4DNXT)

mattology

Furuno Super Fan
Very confused here.

Some channel markers are not being shown by my radar. Last night I was doing some night cruising and sure enough, There were some (maybe 4 out of 20 something) that didn't repeatedly ping on the radar.

I went as far as performing a reset on the radar to factory default settings, and then re-enabled the blanking I have directly aft of the radar, because my SCX20 is below and behind it, and I just want to be careful I am not within the 25 degree range of the radar pulse.

I'm just confused as to why this is happening. Are there certain angles that won't return at all?

I tried both standard, enhanced 1, and enhanced 2 rezboost. didn't seem to make a difference.

What settings should I be using if I am trying to be at a slow trolling or minimum wake zone speed, and have maximum visibility of things like channel markers and better yet, crab buoys?

I tried bird mode, target analyzer, and tried changing the sea state from coastal to advanced.

sorry for being such a newb.
 
I tried to attach a photo but it's saying the maximum file size is exceeded. there are photos of my boat in the sub forum on this site where people can show their builds
 
Qu3tkiC.jpg


DkTvWMf.jpg


EK0NI2Y.jpg


huYlh38.jpg


TZT12F
TZT9F
DFF3D
DRS4D-NXT
SCX-20
BBWX4
FM4800

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I don't see anything that would require sector blanking. From the photo it looks like the radar is clearing the SCX20. (although I would have suggested the SCX20 be in a little more forward) The only concern I see is that front rail of the boat. With the wedge mount, it looks like you might be catching the front rail with the radar. If so you might be creating a strong return that causes the auto tuning to drop down the gains and miss other targets. You might do a test with the sector blanking off and and run manual operations controlling the gain and clutter yourself and see if you pick up the missing targets. The doppler is fully automated so you can't run that mode as you test. If you are able to get the targets controlling the clutter and gain yourself; then odds are you are catching the front rail and might need to reposition the radar because it is throwing off the auto modes. If you can't pick up the targets at all in manual; then I would send the radar in for evaluation because something might be wrong with it. Knowing the product, I think you are catching that rail.
 
I took measurements plus and minus 12.5 degrees from the centerline of the radome to make sure it wouldn't interfere with the bow rail . it is close for the SCX-20, closer than the bow rail. I didnt want to risk it and damage the scx20
 
I will re-confirm measurements and try and provide photo information. from there, we will see and maybe i will send it in.
 
According to my measurements and markup, I am alright...

But it's close. I have about 7 inches of clearance.

I may try and reduce the angle when I am back in the water next summer.



I am trying to upload the entire photo but this website is optimized for mobile ( what kind of bs is this anyway) instead of a wide screen monitor, and thus it's cutting off the image without even giving the option for a resize!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! I have since attached it, so its shrunk down, but you can see it... :angry

link to the photo as well:

https://i.imgur.com/VpbDlU6.jpg
 

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Johnny Electron":2nv95g71 said:
The only concern I see is that front rail of the boat. ... Knowing the product, I think you are catching that rail.

Thanks for the installation pics, theoretically you're right that you miss it by that much. However interestingly, the manual mentions in addition to beam width -- side-lobe level. While you might not be hitting the rail directly, outside the 12.5 degrees are the side-lobes of the radar's RF emission. It's possible to create reflections based on side-lobe refractions.

EDIT: NMEA also states that you should have 2' separation between VHF and the radome.

I'd like to see a side-by-side view of the plotter with these beacons marked and what you see in the radar pic so we can tell what you're seeing.

Hope this helps, :sail

- Maggy
 

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Looking at the area where you are using the boat, it should be in COASTAL mode and not the default. If you haven't tried that, I would suggest you try that before sending it in for evaluation.
 
I may attempt to reduce the angle of the radar wedge from 4 degrees to 2 degrees, and i will try and see how that happens.

the issue where it happened was here:

But after looking at the photos some more and wondering why this is the only place where I have been having issues...

and then i thought some more about where I was, which is the only place i had these issues.


Right next to an airport.

I wonder, who knows, but could the radar from the airport be on a similar enough band to be causing interference with my NXT?

Am i an idiot? (yes)

Could I have damaged my NXT ?
 

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Radar interference typically shows up as a spiral or a wedge shaped spike, both coming from the center of the screen.

I would give the following setting an attempt if you haven't already:
Auto Sea Mode - Coastal
Rezboost - Standard
Gain - Auto
Sea Clutter - Auto
Rain - 0

If that does not work, try lowering your VHF antennas. Based on the first photo it appears they are far enough away but you never know about the inside construction possibly acting like a reflector.

You could also try manual settings. Leave the rain on 0. Set Gain to 40. The set Sea Clutter to 25 and start working the sea clutter down until you get a good return with minimal "clutter". I will say that I have seen day markers give poor returns at angles. They do very well head on. I have one near me that someone hit and the slight angle deflecting upward makes it near impossible for anyone to pick up on radar.
 
FishTech is right about what radar interference will normally look like. While I am sure the Airport radar coming in that close isn't great, I doubt it would damage yours. It can cause your auto tuning to respond badly like to any strong close in reflection or strong RF source by protecting it's ears. That could be causing you some problems with the auto modes but it shouldn't keep your manual operations from working well. I would recommend not using AUTO for a few days and try how the manual works for you as FishTech said. Whenever trying auto; set it to COASTAL unless out offshore. If it is still giving you problems, I would recommend having the unit evaluated at the service center just for a sanity check if nothing else.
 
well I am leaving the country and won't be back for a few months (project management on a job abroad) so I'll have to fight with it some more when i get home... thanks again everyone!
 
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