Raymarine DSM250, Owner'S Handbook Manual

Page: 93 / 122

Chapter 6: Sonar Mode Operation 6-5
Using White Line
The White Line feature separates echoes from fish near the bot-
tom and the bottom itself. When the White Line is switched on,
the sounder displays the echoes differently.
On color LCDs, the strongest echoes are displayed in the back-
ground color with a thin line on top. All other echoes remain
unchanged.
On monochrome displays, the weakest echoes continue to be dis-
played in the background color (white), but colors for the other
signal are reversed. Thus, from the strongest to the second weak-
est the colors are: light gray with a thin black line on top, dark
gray, black.
➤
To switch the white line feature on and off:
1. Press the
MULTI
key (knob). The
WHT LINE
soft key is displayed.
2. Press the
WHT LINE
soft key to toggle the white line feature
ON
or
OFF
.
Adjusting Display Gain (Sensitivity)
The sounder provides controls for
GAIN, COLOR GAIN,
and
STC
.
These controls, accessed from the
GAIN
key (or
GAIN
knob on
radar CRT units), are used to reduce background noise and deter-
mine how different strength echoes are shown. Automatic adjust-
ment of each of these parameters is available; alternatively you
can manually adjust the settings using the trackpad.
Note: Automatic Gain settings take advantage the hardware’s ad-
vanced digital technology. As a result, the sounder typically performs
better in automatic mode than manual.
For better performance Ray-
marine recommends selecting AUTO mode for all Gain options.
If you change the settings, the new
GAIN, COLOR GAIN,
or
STC
val-
ues and mode (auto or manual) remain set even when you turn off
the display.
MULTI
WHT LINE
OFF ON
GAIN
ADJUST
200 50
75%
CRUISING
COLR GAIN
STC
MANUAL AUTO
45%
GAIN
A
U
T
O