Furuno GP-1870F 7.6 Manual Fish Finder Operation

7. FISH FINDER OPERATIONS
7-9
7.6 Manual Fish Finder Operation
Use the manual operation to see schools of fish and the bottom echo with a fixed gain
setting.
The gain, range and range shift functions let you select the depth you can see on the
screen. The basic range provides a "window" into the water column and range shift
moves the" window" to the depth that you select.
To select the manual mode, open the RotoKey menu then select [Auto Mode] and
[Manual].
7.6.1 How to select a display range
Range can be selected automatically or manually. Open the RotoKey menu then se-
lect [Auto Range] and [Auto] or [Manual].
[Auto]: The range is automatically adjusted to always display the bottom echo at the
lower of the screen. When rotate the RotoKeyTM in the auto mode, the message “Auto
Range mode. Can’t change Rage.” appears.
[Manual]: Change the range with the RotoKeyTM. Turn the key clockwise to increase
the range and counterclockwise to decrease the range.
7.6.2 How to shift the range
The basic range and range shift functions let you select the depth you can see on the
screen. This function is not available when the auto range mode is on or the bottom
discrimination feature is active.
Unit Basic Range
123456 7 8
1500
1000
400
200120603015
500
300150
80
40
2010
5
m
ft
fm 300
150
80
40
2010
5
3
pb 300
200
100
30 501053
HR 300
200
1005030
15
83 HR=Hiro (Japanese unit of depth)
pb=passi/braza
Display
Window can be
shifted up and
down to select
starting depth.