4 manual sounder operation, 1 selecting the manual mode, 2 selecting display range – Furuno 1763C User Manual
Page 155: 3 adjusting the gain

4. VIDEO SOUNDER OPERATION
4-9
4.4
Manual Sounder Operation
Manual operation is useful for observing fish schools and bottom using fixed gain
setting.
The gain, range and range shifting functions used together give you the means
to select the depth you can see on screen.
4.4.1
Selecting the manual mode
1. If not displayed, press the [HIDE/SHOW] key to show the sounder soft keys.
2. Press the AUTO/D. BOX soft key to show the auto mode window.
3. Select OFF (MANUAL).
4. Press the RETURN soft key.
4.4.2
Selecting display range
Press the [RANGE +] or [RANGE -] key to select a range. The default ranges in
feet, meters, fathoms and passi/braza are as below. Note that range cannot be
changed in the automatic sounder mode.
Default sounder ranges
Range 1
Range 2
Range 3 Range 4
Range 5
Range 6
Range 7
Range 8
15 ft
30 ft
60 ft
120 ft
200 ft
400 ft
1000 ft
1200 ft
1500 ft
5 m
10 m
20 m
40 m
80 m
150 m
300 m
4000 m
4500 m
3 fa
5 fa
10 fa
20 fa
40 fa
80 fa
150 fa
650 fa
900 fa
3 PB
5 PB
10 PB
30 PB
50 PB
100 PB
200 PB
700 P/B
900 P/B
4.4.3 Adjusting
the
gain
Normally, set the gain to the point where excessive noise does not appear on
screen. Use a higher gain setting for greater depths and a lower setting for
shallow waters.
Gain too high Gain proper Gain too low
Examples of proper and improper gain