How To Balance Echo Strength; Fish Finder Alarms; How To Set An Alarm - Furuno TZT9 Operator's Manual

7.8

How to Balance Echo Strength

A school of fish at a depth deeper than a school of equal strength in shallow water ap-
pears in weaker colors. This condition is caused by the attenuation of the ultrasonic
wave. To display the schools of fish in the same colors, use the TVG. The TVG auto-
matically increases the gain with depth so that echoes of the same strength and dif-
ferent depths are shown in the same colors. In the illustration shown below, for
example, the TVG is set for 300 ft and the TVG level is adjusted. Unnecessary echoes
at a distance less than 300 ft are deleted and echoes at depths greater than 300 ft are
not adjusted.
Note: This function is not available in the auto mode.
1. Select [Menu] on the menu icon bar to open the main menu.
2. Select [Sounder].
3. Drag the circle icon in [TVG HF] (high frequency) or [TVG LF] (low frequency) to
set the level. Raise the TVG to increase the gain difference between near and far
distances.
4. Select [Close] to exit the menu.
7.9

Fish Finder Alarms

Two types of fish alarms release audio and visual alarms to tell you that echoes from
fish are in the area you selected. These alarms are [Fish Alarm] and [Fish Alarm for
Bottom Lock].
The [Fish Alarm] function tells you when an echo above some strength (selectable) is
within the alarm range you specify.
The [Fish Alarm for Bottom Lock] function tells you when fish are within some distance
from the bottom. The bottom lock display must be active to use this alarm.
7.9.1

How to set an alarm

1. Select [Menu] on the menu icon bar to open the main menu.
2. Select [Sounder].
Unwanted echoes
0 ft
300 ft
Echoes of the same size
are displayed in different
sizes and colors
depending on depth.
Unwanted echoes
are erased.
0 ft
300 ft
Echoes of the same size
are displayed in same
sizes and colors.
7. FISH FINDER
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