How To Balance Echo Strength - Furuno NavNet TZtouch3 Series Operator's Manual

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How to Balance Echo Strength

Depending on local ultrasound characteristics, the reflection from a school of fish in
deep water may appear in weaker colors than that from a school in shallow water even
though their strengths are equal. To show the schools of fish in equal strengths (col-
ors), use the TVG. The gain level is adjusted according to TVG level and TVG dis-
tance*, so that echoes of the same strength are displayed in the same colors.
* DFF-3D only.
Note: This function is not available in the auto mode.
The figure shows an example display with proper TVG setting.
1. Open the Home screen, then tap [Settings]→[Fish Finder].
2. Drag the slider in [TVG HF] (or [TVG MF], [TVG LF]) to set the level. The TVG's
function changes according to the fish finder model used, as shown in the table
below.
DFF1, DFF1-UHD, BBDS1,
DFF-3D (version 1.04 or earlier)
Internal sounder (TZT12F, TZT16F, TZT19F),
DFF3 (version 1.05 or later)
3. Tap the close button on the title bar to finish.
0 ft
Echoes of the same size
are displayed in different
sizes and colors
depending on depth.
Fish finder
7. FISH FINDER (SOUNDER)
0 ft
Echoes of the same size
are displayed in same
sizes and colors.
TVG setting method
The higher the setting the stronger
the targets in shallow water.
The higher the setting the weaker
the targets in shallow water.
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