Furuno FR-8125 ユーザーズマニュアル

1.  OPERATION

The selected range scale, range ring interval and pulselength are shown at the upper 
left corner on the screen. When an object target comes closer, reduce the range scale 
so that the target appears in 50-90% of the display radius.

Use the RANGE key to select range. Press the "+" part of the key to raise the range; 
the "-" part to lower the range.

The gain functions to adjust the sensitivity of the receiver for the best reception. The 
gain is adjusted automatically or manually.

1. Press the MENU key to open the menu.
2. Use S or T and select [Echo] and press the ENTER key.
3. Use S or T to select [Gain Mode] and press the ENTER key.
4. Use S or T to select [Auto] or [Manual] and press the ENTER key. 

the window for Gain/Sea/Rain indicator shown below appears. This 
window closes automatically in the [River] or [Sea] mode when there 
is no menu operation for ten seconds. [Auto] is for adjusting the gain automatical-
ly. For [Manual] go to "Manual mode" below.

5. Press the CANCEL/HL OFF key to close the window.
6. Press the MENU key to close the menu.

Note: To adjust the gain finely in [Auto] mode, rotate the GAIN knob. The confirmation 
message appears. If you select [Yes] the mode changes to [Manual] mode. Rotate the 
Gain knob to adjust the gain.

1. Rotate the GAIN knob to adjust the gain so that weak noise appears on all of the 

screen. If the gain is too low, weak echoes are erased. If the gain is too high, the 
background noise hides weak targets.

2. Press the CANCEL/HL OFF key to close the window.

Manual

Auto

Gain/Sea/Rain

GAIN MAN
SEA
RAIN

MAN
MAN

[CANCEL/HL OFF: Close

AUTO: Auto, MAN: Manual

Gain setting bar

Are you sure to change to manual mode?