Furuno CH-270 - Manual (Page 33)

2. HORIZONTAL MODE
2-13
2.11 Adjusting the Picture
2.11.1 Suppressing bottom and surface reflections
In shallow fishing grounds, excessive sea surface and bottom reflections often interfere
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 reduced rather than when the gain is decreased.
1. Press the [MENU] key to open the menu.
2. Press ▲ to choose MENU and then press ◄ to choose the COM1 menu.
TX POWER MAX
PULSELENGTH LONG
TX RATE 10
INT REJECT OFF
AGC OFF
: SELECT : CHANGE MENU: END
MENU COM1 HORZ VERT ES PRESET SYS COM2
AUDIO LEVEL 0
COM1 menu
3. Press ▲ or ▼ to choose TX POWER and then press ► to show the TX POWER
dialog box.
TX POWER
MAX MIN
4. Press ► to choose MIN. (For long range detection be sure to return the setting to
MAX.)
5. Press the [MENU] key to register your selection and close the menu.