Interphace ULTRASCAN PC90, Operation Manual, Page: 30 / 56

30
Adjusting the Gain and
Range
The Gain and Range adjustments are perhaps the
most critical features of Ultrascan PC90 in optimizing
the system performance for different operating
conditions.
Gain and Range can be set manually or, alternatively,
Ultrascan PC90 can set and vary the Gain and Range
settings automatically. It is important to note that
each scanning direction has its own Gain and Range
settings. To change the Gain and Range settings for
the current display, select Gain and Range... from the
Adjust menu.
Gain Adjustment
The Gain level controls the intensity of the signals
shown on the display by varying the amplification of
the sonar signals that Ultrascan PC90 receives. Click
on the Auto box to turn Auto Gain on and off. A
check in the box indicates that Auto Gain is on. The
default setting is off.
In the manual mode, Ultrascan PC90 allows you to
choose from 32 different Gain levels, numbered from
1 to 32. The default level is 16. Select the Gain by
sliding the pointer on the Gain bar. Level 1 provides
the smallest amount of Gain. At this level, the screen
will display little or no data. Higher Gain numbers
will brighten the display. The Gain level required to
see a specific target will vary with target range, water
clarity and background noise. In addition, Range
changes may also require changes in Gain.
In the Auto Gain mode, Ultrascan PC90 will adjust
the gain level automatically depending on the strength
of the sonar signal returns. Note that it is still
possible to make manual adjustments in the Auto
Gain mode, but any adjustments you make could be
changed by Ultrascan PC90.
Range Adjustment
The Range is the maximum distance at which features
will be displayed by Ultrascan PC90. In general,
features at greater distances will be less clearly
resolved. In addition, the water conditions will help
to determine the greatest distance at which Ultrascan