4
50k
49.6
0.0
Fish
school
Bottom
0
20
40
60
80
Figure 1-7 Typical 50 kHz normal display
200 kHz
The higher the frequency of the ultrasonic
pulse the better the resolution. Therefore, the
200 kHz frequency is ideal for detailed ob-
servation of fish schools.
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.
50/200
60
49.6
0.0
50 kHz 200 kHz
picture picture
0
20
40
80
0
20
40
Figure 1-8 Dual-frequency display
Marker-zoom display
This mode expands selected area of the nor-
mal 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. The length
of the segment is equal to one division of the
depth scale.
14.7
0
10
20
30
40
15
20
25
28.2
Zoomed fish
school
Normal
display
Variable range
marker (green)
This section
is zoomed
Zoom marker
(yellow)
Marker-zoom
display
Fish
school
Figure 1-9 Marker-zoom display
plus normal display