4. ADVANCED SETTINGS
4-28
Calibration menu
Use the Calibration menu to apply offsets for the external fish finder.
HF and LF menus
Menu item
Description
[Zero Line Rejec-
tion]
Turns the zero line (transmission line) on or off. When turned [On],
the transmission line disappears, which allows you to see fish
echoes near the surface clearly. The width of the transmission line
changes with transducer used and installation characteristics.
[Zero Line Area]
Adjusts the transmission line so that the transmission line disap-
pears when the [Zero Line Rejector] is turned on. For a long tail, in-
crease the value. If the transmission line does not disappear, lower
the TX power.
[Draft]
The default depth display shows the distance from the transducer.
If you would rather show the distance from the sea surface, set your
ship's draft. The draft line for HF and LF can be set respectively.
[Fish Size]
Compensates for incorrect fish size indications as shown in the ta-
ble below.
[Sound Speed]
Adjusts the sound velocity of the TX/RX signal if the depth indica-
tion is incorrect, often caused by water temperature or salinity.
Menu item
Description
[Bottom Level]
In the default bottom level setting [0], the equipment judges con-
secutive strong echoes to be bottom echoes. If, in that setting, the
depth indication is unstable, adjust the bottom level. If vertical lines
extend upward from the bottom echo in the bottom lock display,
lower the bottom level to erase the vertical lines. If the level is too
low, however, it may be difficult to distinguish bottom fish from the
bottom echo.
[Gain ADJ]
If the gain is too high or too low, or the gain for the low and high
frequencies appears unbalanced, you can compensate it here.
+100%
+50%
-50%
Size of correction
times 2
times 1.5
1/2
-75%
-80%
-65%
1/4
1/3
1/5
Setting (%)
Size of correction
Setting (%)
