Yellow circle on radar screen

[cbd@gov-consult.com]

Can someone tell me how to get this yellow circle off my 48 mile Furuno radar screen.
See attached. Thank you,
Bruce Dickinson

 

[Taniwani]

You get a yellow circle when the main bang suppression is shorter than the pulse length. On most radars you don't have a way to adjust either.

Might be able to narrow it down further if you let us know what type of radar and what settings like range are.

 

[cbd@gov-consult.com]

Just bought the boat and I am not on it. Picture of unit attached. Never had this issue on my previous Furuno. Is it some kind of defect in this unit?
Thanks

 

[Johnny Electron]

It is either installation error (Main bang or timing not properly setup during installation) or water in the antenna (which can also create a ring). Is this a dome or open array radar?

 

[cbd@gov-consult.com]

Open array.

 

[Taniwani]

Was the picture taken at range 48? At what range is the yellow circle?

 

[Johnny Electron]

If not main bang and timing adjustment, then the installer most likely didn't seal the antenna on the gearbox as required. Water gets into the joint and messes everything up. Take a look under the antenna stick. Did they seal over the bolts and do you see sealant around where the radar stick meets the gearbox?