1. OPERATION
11
3. Use
S
or
T
to select Clutter and press
the [ENTER] key.
4. Use
S
or
T
to select HF Curve or LF
Curve as applicable and press the [EN-
TER] key. The setting box shown below
appears.
Std:
Strong color echoes are displayed
as is and weak color echoes are shown
smaller, when the clutter level setting is
raised.
Linear:
All echoes are displayed smaller,
when the clutter level setting is raised.
H:
Show individual fish.
L:
Show small targets such as plankton.
S:
Display large individual fish located be-
tween the surface and midwater.
Custom:
Emphasize strong-to-medium
strength echoes. See User Clutter of sec.
2.2.1 “User menu description”.
5. Use
S
or
T
to select setting desired and
press the [ENTER] key.
6. Use
S
or
T
to select HF Clutter or LF
Clutter as applicable and press the [EN-
TER] key.
7. Use
S
or
T
to set clutter level and press
the [ENTER] key. The setting range is 0-
100(%), in intervals of 10(%). The larger
the setting, the greater the degree of clut-
ter rejection.
8. Press the [MENU/ESC] key several times
to close the window.
1.14
Adjusting TVG
A fish school at a deep depth is displayed in
weak colors even if it is equal in strength to
one in shallow waters. This is due to propaga-
tion attenuation of the ultrasonic wave. To
compensate for this difference, use TVG.
TVG automatically adjusts the gain with depth
so that echoes of the same strength and dif-
ferent depths are shown in the same colors
regardless of their depths. The gain is in-
creased with depth to display echoes of equal
strengths in the same colors. Furthermore,
you can suppressed unwanted echoes near
the surface. For example, in the figure below,
the TVG is set for 100 m and the TVG level is
adjusted. Then, unwanted echoes at a dis-
tance less than 100 m are deleted and echoes
at depths greater than 100 m are not affected.
1. Press the [MENU/ESC] key to open the
menu.
2. Use
S
or
T
to select Sounder and press
the [ENTER] key.
IMPORTANT
Do not set the TVG too high; close-range
echoes may not be displayed. Carefully
adjust the TVG while observing the display.
0 m
100
0 m
100
Unwanted
echoes appear.
Unwanted
echoes suppressed.
TVG OFF:
Fish schools of
equal strengths
shown in different
sizes and colors.
TVG adjusted:
Fish schools of
equal strengths
shown in same
sizes and colors.