48 DS400 and DS500 Digital Fishfinders
• Sounder Interference Rejection (Int. Rej.)
• Second Echo Rejection
• Power
• Maximum Ping Rate
Use the trackpad to scroll through the sub-menu items.
➤ To set a Manual Gain value in any of the following sub-menus:
1. Use the trackpad to highlight MANUAL.
2. Press ENTER. Normal (not highlighted) text appears.
3. Press the or > Trackpad key to increment and the or < Trackpad key
to decrement the Gain setting.
4. Press ENTER to accept the MANUAL value.
GAIN
The gain, or sensitivity, of the display adjusts background noise by varying
echo strength for display. The value of the gain control determines the
strength above which echoes are displayed. If the gain is low only the
strongest echoes are displayed. As the gain is increased, weaker echoes (from
air bubbles, for example) are also displayed.
The automatic gain modes find the ideal sensitivity level for you, based on
depth and water conditions. Automatic gain modes take advantage of the
hardware’s advanced HDFI technology. As a result, the sounder typically
achieves a sharper image in any of the automatic gain modes than is possible
in manual mode.Automatic gain varies the gain throughout the water column
based on the current conditions.
The DS400/500 provides three pre-defined automatic gain settings:
• AUTO FISHING is the highest automatic gain setting. It gives the best
details of the targets you have located and is ideal for slow speeds and
drifting.
• AUTO TROLLING is a medium gain setting that is better suited for trolling
speeds.
• AUTO CRUISING is the lowest automatic gain setting, ideal for reducing
background noise or travelling to your fishing spot at high speeds.
• MANUAL gain should be set high enough to see fish and bottom detail but
without too much background noise. Generally, a high gain is used in
deep and/or clear water; a low gain in shallow and/or murky water.
The default setting is AUTO FISHING.