Radar Blues

[DERF]

Spent the weekend trying and unable to make head or tail of my radar images.. Have Furuno 1833 Navnet with a 2' radome.. Cannot get a decent image and when I do the trace is very confused!.. or perhaps that's just me..

mjf has the same kit and was a great help, and his picture definition was far superior to mine with all the same settings. albeit he has a 4' open array scanner.

Does anyone have any insight into the improvement in picture betwenn a open array and raydome? could mine just be a poor installation/setup problem or is the open array vastly superior.

I am close to reverting to Raymarine e series and junking the Furuno as although the Furuno is a more sophisticated piece of kit, I'm struggling to get comfortable with it all... IMO the Raymarine is much more user firendly and easier to interpret.

Thanx again mjf for you help..

 

[pvb]

Radome vs Open Array...

This is another of those cases where size really is important! The 2' Furuno radome has a horizontal beam width of 3.9 degrees, but their 4' open scanner has a beam width of only 1.85 degrees. Narrower beam width gives greatly enhanced target definition.

 

[Deleted User YDKXO]

The difference between a 2' closed dome and a 4' open one should not be enough to make you want to junk your radar. Perhaps you might clearer definition of smaller targets but the 2' dome radar should be perfectly usable. Furuno are one of the best names in the radar business so either the installation is faulty or, with all dues respect, your skills need brushing up. Worthwile doing a RYA Radar course held by someone like Robert Avis Ramar and much cheaper than changing your radar

 

[hlb]

Nah. Radars easy. Just turn all the clutter and tune things down to zerro and turn the gain up till it just starts to get a little bit speckly and that should be the best picture yer goin to get. Mind radar is a bit rubbish if sat in marina. Go out to sea about 3 miles and see what you can pick up then.

 

[mjf]

We did that, started fron scratch and then adjusted everything to mirror my set up.

IMO the difference between dome and open will not be that great the way we were using it. Certainly definition between two close objests will be clearer on the open scanner due beam width as stated above.

I think the scanner/ connections to the display are suspect.

DERF told me that with a big metal channel buoy a mile away he could not get an echo. In the marina I get a clear picture of pontoons - can track craft moving about etc . DERF's set shows a smudge of colour with little outline and misses half the echoes expected to show. This is when it set to best set-up I could achieve. So leads me to think the tuning is getting corrupted somehow...... If you turn the gain right up there is so much grass you need a Flymo!

 

[ShipsWoofy]

Can you take your set to his boat and run it with his scanner.

I have read your message a few times and am struggling to work out if you may have a video fault or you just think your picture should be as clean as his with a different array?

If it is a video fault, have a good look at the video element of the cable, that is the coax part, usually looks like a wire with a thick insulator and wrapped in tin foil. (Sorry if this is teaching you to suck eggs).

It is important that this cable is not bent but rather curved. Check any through hull connections, make sure the screen is unbroken.

If I am off the mark as to your complaint, obviously ignore this message....

 

[DERF]

Initial report

I have now had Furuno on board who from their first diagnosis indicate that the scanner/software/installation is at fault.

They have confirmed that the radar picture changes and inverts when the gyro picks up movement. (as I said mjf) The ARPA, even when not on automatic acquisition, locks on to non existant targets on the horizon and scrambles parts of the image. The arpa is also creating an exclusion zone of 1-4 points off the port bow.

In asnwer to my question about the scanner resolution they have indicaed that a 4' open array will increase picture definition and separation by over 2x.

They will do a full diagnosis and report findings and recommendation.

Lets wait and see.