Chapter 5
RA83/84/85/93/94/95 Series
Basic Operation
Operation Manual
Table 5.1 Range vs Transmission Pulse Length
RANGE (NM) Pulse code Pulse length (6/12kW)
Pulse length (25kW)
0.125
SP
0.08 us
0.08 us
0.25
SP
0.08 us
0.08 us
0.5
SP
0.08 us
0.08 us
0.75
SP
0.08 us
0.08 us
M1P
0.25 us
0.3 us
1.5
SP
0.08 us
0.08 us
M1P
0.25 us
0.3 us
3
M1P
0.25 us
0.3 us
M2P
0.5 us
0.6 us
6
M1P
0.25 us
0.3 us
M2P
0.5 us
0.6 us
12
M2P
0.5 us
0.6 us
LP
1.0 us
1.2 us
24
LP
1.0 us
1.2 us
48
LP
1.0 us
1.2 us
64 (6KW)
LP
1.0 us
72 (12KW)
LP
1.0 us
96 (25KW)
LP
1.2 us
5.5.3 Gain control
The GAIN control is used to change the receiver gain. The gain control can be
switched to manual or auto mode by ADJUST/ADJUST MENU. When the equipment
is turned on at first, the gain control will be defaulted to manual mode.
Set the gain control as appropriate to your operational needs. As a standard setting,
turn the GAIN control clockwise to 3/4 of the full excursion. This provides slight noise
speckles on the mid ranges and adequate speckles on the long ranges.
To set the auto gain mode, select AUTO1, AUTO2, or HARBOR by ADJUST/ADJUST
MENU. The receiver gain will be automatically set and the manual gain control will
accordingly become inactive.
5.5.4 Anti-clutter SEA control
The Anti-clutter SEA control is used to reduce the clutter echo appearing around the
center of the screen, which is caused by the echo return from the sea surface. The
effect of the control is highest at the center of the screen and reduces with distance.
The Anti-clutter SEA control is effective up to approximately 6 NM, which can be
switched to either manual or auto mode by ADJUST/ADJUST MENU. When first
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