Furuno FSV-85, Operator'S Manual

Page: 45 / 184

2. HORIZONTAL MODE
2-19
2.9.6 Reverberation
You may select the length of reverberation for the echo signal, with [Reverberation] on
the [TX/RX Setting] (H1 or H2 tab). The setting range is 0-3. The larger the value, the
lower the reverberation effects. Set the length of reverberation properly to make it eas-
ier to see the echo signal.
2.9.7 Echo average
[Echo Average] (H1 or H2 tab) on the [Picture Setting] menu adjusts echo afterglow -
the amount of time an echo signal remains on the screen. This feature can be useful
for watching echo movement. The setting range is 0-7.
Setting between 1 and 3 :
Echoes are gradually displayed and afterglow remains on the screen longer as the
setting is increased.
Setting between 4 and 7 : Echoes are quickly displayed and af-
terglow remains on the screen longer as the setting is increased.
2.9.8 Reference bearing in frequency shift
The reference bearing in frequency shift can be changed to avoid sonar interference
and noise. If noise or interference appears at a specific bearing, change the value of
the [Freq/Bearing Set] in the [TX/RX Setting] (H1 or H2 tab) - [Frequency] menu. The
setting range is 0°-358° and the default setting is 0°.
Note: [Freq/Bearing Set] is valid when [Sidelobe Sup. A] (see paragraph 2.9.9) is se-
lected to other than 0°).
2.9.9 How to suppress sidelobes
False echoes produced by sidelobes may appear on the display depending on the dis-
tribution pattern of a school of fish and the positional relationship between it and a ma-
rine object (reef, etc.) and wake reverberation. To reduce these sidelobes, use
[Sidelobe Suppress] in the [TX/RX Setting] menu (H1 or H2 tab).
Sidelobe suppression A
Watch the echoes while adjusting the suppression. The setting range is -3 to 4 (0 is
OFF). The larger the setting, the more the sidelobe is suppressed. For greatest sup-
pression, use a negative setting (-3 to -1).
Note: When a negative value is used, [TX/RX Mode] in the [Display Setting] menu is
automatically selected to [Alternative]. See "TX/RX Mode" on page 7-3 for details.