Radar fading?

[jmp]

Aquired a Furuno 1720 radar,and in testing at home in garden seems ok,but after 10 mins or so the targets fade away.Everything else seems still running.
Has anyone any idea what may be causing the symptoms?

 

[ShipsWoofy]

Sounds like a problem with the tuning circuits. On these small marine RADARs the tuning can be altered via the software, next time you try it, enter the menu's and try retuning and see what happens.

This is certainly a fault and the radar should not drift, but retuning should knock it out of auto and may actually sort out the problem for you. If tuning does not fix it, it could be dropping power as it gets hot.

There are quite a few things it could be, none of which is very easy to diagnose over a forum.

Also, if you switch to standby and then re-power, what happens?