Furuno Ls4100 - Manual (Page 9)

3
Single frequency display
50 kHz
The sounder uses ultrasonic signals to
detect bottom conditions. The lower the
frequency of the signal, the wider the
detection area. Therefore, the 50 kHz
frequency is useful for general detection
and judging bottom condition.
200 kHz
The higher the frequency of the
ultrasonic signal the better the
resolution. For this reason the 200 kHz
frequency is ideal for detailed
observation of fish schools.
50 kHz
200 kHz
Frequency and coverage area
46.6
Fish
School
Bottom
0
20
40
50k 1/1
0.0
Level Bar
Depth
Frequency
Picture Advance Speed
Range Scale
Mode
(AUTO or MANUAL)
40.7 ° F
16.2kt
Nav Display
Minute
Marker
(Shows time.
Each bar
is 30 sec.)
Transmission
Line
60
Typical 50 kHz display
Dual frequency display
The 50 kHz picture appears on the left;
the 200 kHz picture on the right. This
display is useful for comparing the same
picture with two different transmitting
frequencies.
50 kHz 200 kHz
picture picture
49.6
0.0
50/200 1/1
0
20
40
60
80
20
40
60
80
Dual frequency display
Marker-zoom display
This mode expands chosen area of the
normal picture to full vertical size of the
screen on the left-half window. You may
specify the portion to expand by
operating the VRM (Variable Range
Marker), which you can shift with ▲ or
▼. The area between the VRM and
zoom range marker is expanded.
Zoomed
fish
school
Single frequency display
Variable range
marker
This section
is zoomed
Zoom marker
Marker-zoom display
17.0
25.0
0
Fish
school
0
40
10
20
30
0.0
50k 1/1
21
20
19
18
17
22
Marker-zoom display