Furuno FAR-2218, Operator'S Manual, Page: 69 / 294

1. OPERATIONAL OVERVIEW
1-47
1.29 How to Reject Second-trace Echoes
In certain situations, echoes from very distance targets can appear as false echoes
(second-trace echoes) on the screen. This occurs when the return echo is received
one transmission cycle later, or after a next radar pulse has been transmitted.
This equipment lengthens the pulse repetition period to reject false echoes.
Note: his function decreases the number of echo hits. Use this function carefully so
that the possibility of detecting small targets and high-speed craft does not lessen.
To enable or disable second-trace echo rejection, do the following:
1. Open the menu.
2. Select [1 ECHO].
3. Select [3 2ND ECHO REJ].
4. Select [ON] to enable second-trace echo rejection.
Select [OFF] to disable rejection.
5. Close the menu.
Pulse
interval
Actual ranges
Second-trace
echo
Measured ranges