Raymarine C140w - Manual (Page 160)

4. Use the rotary control to select the amount of gain you want,
between a value of 1 to 100. (The default value is 75).
5. Press the OK button.
The new values remain set even when you switch off the display,
they are applied to both the active window and any other fishfinder
windows displaying the same frequency.
Fishfinder color gain
You can adjust the color gain to change the signal strength threshold
for the strongest color in your fishfinder display.
Color gain sets the lower limit for the strongest echo color. All
echoes with a signal strength above this value are displayed in the
strongest color. Those with a weaker value are divided equally
between the remaining colors.
• Setting a low value produces wide band for the weakest color, but
a small signal band for the other colors.
• Setting a high value gives a wide band for the strongest color, but
a small signal band for the other colors.
There are two color gain modes:
• Auto. In Auto mode the color gain setting is automatically
adjusted to suit current conditions. Any adjustments made apply
to all fishfinder windows.
• Manual. You can set the color gain manually, between a value
of 1 to 100.
Adjusting the fishfinder color gain
From the main fishfinder screen:
1. Press the PRESENTATION softkey.
2. Press the GAIN softkey.
3. Press the COLOR GAIN softkey until the MAN option is selected.
4. Use the rotary control to select the amount of color gain you
want.
5. Press the OK button.
The new values remain set even when you switch off the display
and are applied to all fishfinder windows.
Fishfinder color threshold
The color threshold setting determines the range of colors used on
screen. The effect of this is to set a color threshold below which
targets are not shown. For example a low setting would result in
only the strongest (orange and red) targets being displayed.
Adjusting the fishfinder color threshold
From the main fishfinder screen:
1. Press the PRESENTATION softkey.
2. Press the GAIN softkey.
3. Press the COLOR THRESHOLD softkey.
4. Use the rotary controller to select the required color threshold.
5. Press the OK button.
Fishfinder TVG (Time Varied Gain)
The Time Varied Gain (TVG) function reduces the amount of clutter
in the fishfinder display by varying the gain throughout the column of
water. This function is useful for reducing the appearance of ‘noise’.
• Increasing the TVG value increases the maximum depth to which
TVG is applied. A high value decreases the gain in shallow water
so that only the strongest echoes are displayed.
• Decreasing the TVG value reduces the maximum depth. A low
TVG value has little effect on gain in shallow water.
160 C-Series Widescreen user reference