Furuno CH-500, Operator'S Manual

Page: 54 / 109

2. HORIZONTAL MODE
2-16
2.13 How to Adjust the Picture
2.13.1 How to suppress seabed/surface reflections with TX power
In shallow fishing grounds, excessive sea surface and bottom reflections often inter-
fere with wanted fish echoes and they cannot be eliminated sufficiently with the TVG
controls. In such cases, try to reduce the output power, without turning down the gain.
The picture becomes clearer when output power is reduces rather than when the gain
is decreased.
1. Press the MENU key to open the menu.
2. Press
S
to select the menu bar.
3. Press
X
or
W
to select [COM1].
4. Press
T
to select [TX Power], then press
X
to show the [TX Power] settings.
5. Press
X
to select [Low].
For long-range detection, this setting should be set to [High].
6. Press the MENU key to close the menu and apply the changes.
2.13.2 How to suppress bottom tail with pulselength
Fish schools near the bottom are sometimes difficult to detect because you have to
discriminate fish echoes from the seabed reflections. To help discriminate fish echoes
near the seabed, use a short pulselength to decrease the tail from seabed reflections.
1. Press the MENU key to open the menu.
2. Press
S
to select the menu bar.
3. Press
X
or
W
to select [COM1].
4. Press
T
to select [TX Pulselength], then press
X
to show the [TX Pulselength]
settings.
5. Press
X
to select [Short].
6. Press the MENU key to close the menu and apply the changes.
TX OUTPUT POWER: HIGH TX OUTPUT POWER: LOW