Furuno NAVNET TZ2 TZTL12F - How to Balance Echo Strength

7. FISH FINDER (SOUNDER)
7-13
7.12 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 TVG can be adjusted according to water depth*, TVG level so
that echoes of the same strength at different depths are shown in the same colors.
* DFF-3D only.
In the illustration shown below, for example, the TVG is set for 300 ft and the TVG
level is adjusted.
Note: This function is not available in the auto mode.
1. Open the home screen, then tap [Settings]→[Fish Finder].
2. Drag the slider in [TVG HF] (high frequency) or [TVG LF] (low frequency) to set
the level. The menu item on the DFF-3D is “[TVG]”. The TVG setting method
changes with the fish finder connected.
3. Tap the close button on the title bar to finish.
The TVG can also be set from the Layers menu.
Fish finder TVG setting method
Internal fish finder (For TZTL12F, TZ-
TL15F or TZT2BB), DFF1, DFF1-UHD,
BBDS1, DFF-3D
The higher the setting the greater
the distance gain.
DFF3 The higher the setting the lower
the distance gain.
Echoes of the same size
are displayed in different
sizes and colors
depending on depth.
Echoes of the same size
are displayed in same
sizes and colors.
0 ft
300 ft
300 ft
0 ft