Operation Manual

Page 120 CP190i and CPF190i
17.9 INTERFERENCE REJECTION
Figure 17.8 - Interference Rejection menu
Turns On or Off a filter to remove noise from other Fish Finder or Depth Sounders that may
be near by when fishing.
17.10 SENSITIVITY MENU
All settings in the Sensitivity menu are related to the selected Fish Finder transmit frequency
(50 or 200kHz).
Figure 17.10 - Sensitivity menu
17.10.0 Gain
Allows you to control the Sensitivity of the unit’s receiver from 0 to 100%. To see more detail,
increase the receiver Sensitivity by selecting a higher Gain percentage. If there is too much
detail or if the screen is cluttered, lowering the Sensitivity may increase the clarity of the
display.
NOTE
When the Gain Mode option is set to Auto, the receivers Gain cannot be changed.
When the Gain Mode option is set to Manual, the Gain can be manually adjusted. When switching
from Automatic to Manual Mode, the Gain + Offset value is copied into the Manual Gain setting of
the receiver.
17.10.1 STC (Sensitivity Time Control)
The STC function attenuates echoes from surface down to the specified STC depth by
changing the sensitivity of the receiver, decreasing it near the surface and gradually
increasing it as the depth increases. STC impacts bottom finding so can be particularly
useful i.e. to better track a rock sea bottom distinguishing it from the mud in suspension over
it for example when close to rivers outlet to the sea (consider to use at same time also Dual
Frequency mode and White Line for an easier identification of real sea bottom), as well as
to solve issues in false bottom detection when in presence of significant surface clutter.
Its default value is SHORT for the 200 kHz frequency and MID for the 50 kHz frequency.
Such values are good in most conditions. However when navigating in very shallow waters