Furuno GD-1700C - Manual (Page 154)

4. VIDEO SOUNDER OPERATION
4-10
Press the [GAIN] key to show the gain window, and rotate the [ENTER] knob to
set the gain. Current level is shown on the bar. Press the RETURN key to finish.
The setting range is 0-100.
GAIN - HF
27 ▲
HIGH
LOW
▼
Gain window
Note 1:
On the dual-frequency display, the gain can be independently set for LF
and HF. Use the FREQ LF/HF soft key to select the frequency for which
to adjust gain.
Note 2: Gain cannot be adjusted in the automatic sounder mode. The message
“SOUNDER GAIN CANNOT BE CHANGED IN AUTO MODE” is
displayed when you attempt to do so.
4.4.4 Range shifting
The basic range can be thought of as providing a “window” into the water column
and range shifting as moving the “window” to the desired depth. The basic range
may be shifted up or down as desired by pressing the SHIFT soft key followed
by adjusting [+ RANGE -] key. Press the RETURN soft key to finish.
Shift
Shift concept