Raymarine DSM300 User Manual

Also see for DSM300: Installation manual Install guide

Contents

Raymarine DSM300 User Manual Manual pdf 67 page image

Chapter 5: Sonar Mode Operation 67The DSM300 provides three pre-defined automatic gain settings:CRUISING is the lowest automatic gain setting. It is ideal for viewing sonar imagewith a minimum of background noise as you are travelling to your fishing spot.TROLLING is a slightly higher gain setting that displays more detailed echos asyou search for targets.FISHING is the highest automatic gain setting. It gives the best details of thetargets you have located but also displays the most background noise and surfaceclutter.Note:The automatic gain modes are named so as to suggest when you might use them.However, it is not necessary for you to select, for example, Fishing Mode only when you arefishing. You may want to take advantage of Fishing Mode’s higher gain even when cruis-ing at high speeds. Your personal preference should determine which automatic gainmode you use, not necessarily your boat speed.Color GainThe COLOR GAIN determines how echoes of different strengths are displayed.Three shades of gray (monochrome display) or seven colors (color LCD) perpalette are available and the echo strengths are divided into three (monochrome)or seven (color) bands to correspond with each shade of gray/color.The color bar on the right hand side of the display, when set to ON in the Sonar SetUp menu (see Section 3.4), shows the colors being used, with strongest echocolor at the top and the weakest echo color at the bottom.The COLOR GAIN control sets the lower limit for the top color band:All echoes with a signal strength above this value are displayed in the strongestshade/color.All echoes weaker than this value are divided equally between the remainingshades/colors.Setting a low value produces wide band for the weakest color, but a small signalband for the other colors; setting a high value gives a wide band for the strongestcolor, but a small signal band for the other colors.Note:On a color LCD, the sounder also provides a COLOR THRESHOLD control to reducethe number of colors displayed. Use COLOR THRESHOLD with COLOR GAIN to determinehow echoes are displayed.The DSM300 provides automatic or manual COLOR GAIN adjustment. Automaticadjustment displays colors based on current conditions, with as many colors aspossible, while minimizing noise and clutter. As conditions change the auto-colorgain adjusts. If you select manual adjustment, you will need to re-adjust the gainas conditions change.CRUISINGAUTO45%GAINMANUALCLR GAIN50%