Erasing Weak Echoes - Furuno FCV-667 Operator's Manual

Operate the [RANGE] switch and the display shown below appears. Adjust the [RANGE] control
again to select a basic range.
RANGE: 30 ft
Note: The [RANGE] switch is inoperative when the auto function is active.
2.7.2 Range shifting
The basic range may be shifted up or down with the [SHIFT] keys ([+], [-]). Press a [SHIFT] key
and the display shown below appears. Press a [SHIFT] key again to select the amount of shift.
SHIFT: 0 ft
Note 1: The maximum shift range is 1000 feet (300 m). However, actual range will depend on
underwater conditions. In the worst case echoes will not appear.
Note 2: Basic ranges can be changed on the system menu [3].
Note 3: The unit of depth may be selected on the system menu [1].
Note 4: The range cannot be shifted when the auto function is active.
2.8

Erasing Weak Echoes

Dirty water or reflections from plankton may be painted on the display in green or light-blue.
These weak echoes may be erased as follows:
1. Press the [SIG LEV] key. The following display appears.
SIGLVL: 1
2. Press the [SIG LEV] key again to select signal level (echo color) to erase. Every pressing
deletes the weakest color echoes on the screen, up to the light-blue echoes. You may
identify the deleted colors on the color bar; deleted colors disappear from the color bar. The
selected level is shown as SL1, SL2 or SL3 at the top of the screen. Signal level "0" disables
this function.
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