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2.5 TVG Level
TVG (Time Varied Gain) compensates for
propagation attenuation of the ultrasonic
waves. It does this by equalizing echo pre-
sentation so that fish schools of the same size
appear in the same density in both shallow
and deep waters. In addition, it reduces sur-
face noise. Note that if the TVG level is set
too high short range echoes may not be dis-
played.
1. Turn on the power while pressing any key.
2. Press the A-SCOPE key three times. The
start-up screen appears and shortly there-
after the TVG SELECT display appears.
TVG SELECT
▲▼: 50kHz
ts: 200kHz
50kHz= 5(0~9)
200kHz= 5(0~9)
Figure 2-5 TVG select display
3. Operate the Cursor Pad to set level. The
default TVG level for both 50 kHz and
200 kHz is 5.
4. Press the POWER key to escape.
2.6 Echo Offset
The echo offset feature functions to compen-
sate for too weak or too strong echo level. If
the on-screen echo level appears to be too
weak or too strong and the level cannot be
adjusted satisfactorily with the gain controls,
do the following to adjust echo level:
1. Turn on the power while pressing any key.
2. Press the SIG LEV key three times. The
start-up screen appears and shortly there-
after the ECHO OFFSET display appears.
ECHO OFFSET
▲▼ : 50kHz
ts: 200kHz
50kHz= 0(-99~ +99)
200kHz= 0(-99~ +99)
Figure 2-6 Echo offset display
3. Operate the Cursor Pad to adjust level.
The default echo offset is 40 for 50 kHz;
0 for 200 kHz.
4. Press the POWER key to escape.