3.5 Suppressing Main Bang
If main bang appears at the screen center, suppress it as follows.
Procedure
1) Turn on the power. Transmit on a long range and then wait ten minutes.
2) Adjust [GAIN] control to show a slight amount of noise on the display.
3) Select the 0.25nm range. Adjust the [A/C SEA] control to suppress sea clutter.
4) Open the tuning compartment on the control unit.
5) Set VR901(MBS-L) at two o'clock and then slowly turn VR902 (MBS-T) clockwise to
suppress main bang.
6) If main bang still exists, turn VR901 clockwise slightly, and then slowly turn VR902 clock-
wise. Note that excessive main bang erases targets in close range.
Figure 3-5 Control unit, location of tuning compartment
3.6 Confirming Tuning
The radar receiver can be tuned both automatically and manually. Confirm that the radar can be
tuned both automatically and manually.
Procedure
1) Turn on the power. Set the TUNE switch in the top right hand panel to MANU.
2) Transmit on the 48nm range.
3) Adjust sensitivity and picture brilliance. Turn the [A/C SEA] and [A/C RAIN] controls
fully counterclockwise (off).
4) While observing the picture, turn the [TUNE] control in the tuning compartment slowly
counterclockwise (clockwise) more than twice to get best (worst) tuning point.
3 - 4
TUNE
switch
AUTO
Up: AUTO
Down: MAN
MAN
ON
OFF
MBS-L
MBS-T
DEGAUSS
PM-ON/OFF
Tuning compartment
TUNE
TUNE
control
GYRO SET
HOLD
VR901
(MBS-L)
VR902
(MBS-T)
ERROR
STBY