JRC JFE-400, Instruction Manual

Page: 40 / 104

4. Operation
4-2
Gain control [GAIN]
・
Gain can be set to 41 stages of 0
～
40.
・
Touch on top screen. The button color change to yellow green and gain menu is displayed.
・ Auto gain mode or manual gain value is displayed with red highlight on screen.
・
Auto or manual range mode can be set with each touch.
・ Whenever is touched, the sensitivity is raised.
・
Whenever is touched, the sensitivity is lowered.
・
When touch or , , auto range is released automatically.
・ When auto gain mode is canceled, the gain setting is continued and doesn
’
t return before the auto gain
mode.
・
After setting the gain. touch and gain menu is closed.
・ When 2 transducers are installed, touch the again to switch to the CH2 setting.
 About the sensitivity setting
・
Note that the obstacle might be caused to sounding when the setting of sensitivity is inappropriate.
・
The reflection from sea bottom is different according to the condition of sea bottom. The reflection weakens
like sand and mud, etc. though a strong reflection returns like the bedrock.
・
It becomes impossible to recognize sea bottom when the reflection is weak and the depth value might not be
displayed. For this case, bottom of the sea is displayed in red by raising sensitivity. However, dirt and the
plankton, etc. in the sea are mistaken when sensitivity is raised too much for sea bottom, it recognizes, and a
wrong depth value might be displayed.
・
As for the setting of sensitivity, extent to which sea bottom is displayed by a red or an orange color is proper.
Note
・
When setting to an auto gain, the STC curve becomes
“
LONG" regardless of the setting of STC.
Sensitivity is too low.
When sea bottom is
a red or an orange
color, the display
sensitivity is proper.
Sensitivity is too high.