Sonar Sensitivity Controls; Frequency Tuning - Raymarine LIGHTHOUSE 4 Operation Instructions Manual

19.11 Sonar sensitivity controls

Optimum performance is usually achieved using the default settings. You
can adjust the image using the Sensitivity controls to improve the displayed
image. Sensitivity setting adjustment is also applied to the sonar history.
Sensitivity settings can be accessed using the onscreen
[Image adjustment] icon, or the Adjust sensitivity menu
option: [Menu > Adjust sensitivity].
The Sensitivity controls available are dependent upon the transducer and
sonar module in use.
Connector
Description
['G' Gain]
The control determines the signal strength at which
target returns are shown onscreen.
The Gain control can be set to [Auto] or [Manual].
Depending on Sonar module, in Auto you can add
an offset of up to ± 50%.
A higher value produces more target returns and
noise onscreen.
['I' Intensity], or
['CG' Color Gain]
The control sets the lower limit for the color used
for the strongest target returns. All target returns
above this value are displayed in the strongest
color. Those with a weaker value are divided
equally between the remaining colors.
The control can be set to [Auto] or [Manual].
Depending on Sonar module, in Auto you can add
an offset of up to ± 50%.
268
Connector Description
['SF' Surface Filter] , or
['NF' Noise filter]
The control determines the amount of noise
displayed onscreen by varying the gain throughout
the water column.
A lower value decreases the depth at which the
control is applied.
The control can be set to [Auto] or [Manual].
[All to Auto]
Sets all Sensitivity settings to [Auto] with 0% offset.

19.12 Frequency tuning

When using an Airmar® CHIRP transducer you can adjust the frequency of
the 'Tuned' sonar channels (e.g.: 50 kHz, 200 kHz channels.), using the
[Tune frequency] control.
The [Tune frequency] setting can be accessed using the onscreen controls
and from the [Sounder] settings menu.
Note:
The [Tune frequency] control is available when using CP470, CP570,
RVX1000, RVM1600, Axiom Pro RVX and Axiom 2 Pro RVM sonar modules.
The [Tune frequency] control is not available when using the CP370 sonar
module.