CVS-833/833C
Chapter 6
Using the Menu
Operational notes for STC amplitude adjustment
(1) STC law A: STC is not enough, causing noise and unwanted residual weak echoes in shallow
and mid depth zone to be shown.
(2) STC law B: STC is appropriate, causing unwanted echoes to be perfectly reduced while schools
of fish are shown without degradation.
(3) STC law C: STC is too much, causing the echoes from fish school to be reduced too much.
6.7 MENU 4
Figure 6.7 Menu 4 display
CMP SUB
10
1
00.0
1/3
: Mod
MENU : Exit
MENU 1
MENU 2
MENU 3
MENU 4
MENU 5
MENU 6
MENU 7
Mix Type
Return
: MENU No. Select
Panel Illum
Bottom Start
Draft
Output
Using MENU 4, the following functions can be
used:
1. Changing transmission output (High / Low
frequency)
2. Setting a depth for bottom detection.
3. Matching to the ship’s draft
4. Adjusting the operation panel illumination
5. Changing the composite image processing
h d
6.7.1 Output (Adjusting output power)
Fish image
This function allows reducing acoustic power for the following applications:
z
To decrease noise and interference from other boat’s sounders, reduce the power. This is
effective in minimizing the interference.
z
To better display school of fish near the bottom, reduce the power. This allows reducing signal
return from the bottom, thereby the fish echoes can be better discriminated.
Initial setting: 10
Setting range: 1 (weak) to 10 (strong)
Bottom and fish echoes are reduced
in sensitivity, thus both images are
easy to discriminate.
Figure 6.8 The effect by reducing power
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