5.5SENSITIVITY MENU
All settings in the Sensitivity menu are related to the selected Fish Finder transmit frequency (50 or 200kHz).
Figure 5.5 - Sensitivity menu
5.5.0Gain
AllowsyoutocontroltheSensitivityoftheunit’sreceiverfrom0to99%.Toseemoredetail,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.
5.5.1STC (Sensitivity Time Control)
The purpose of this selection is to filter surface noise.
The STC functions reduces or eliminates Surface Clutter signals by changing the Sensitivity of the receiver, decreasing it near the surface and gradually increasing it as the depth increases. Its default value is SHORT for the 200kHz frequency and MID for the 50KHz frequency. Such values are good in most conditions. However when navigating in very shallow waters it may be necessary to switch it to OFF, while in very deep waters with a lot of Surface Clutter it may be better to increase it to MID or LONG.
NOTE
In some situations it may be necessary to adjust the STC so the sounder can read through the surface noise and show the bottom. One indication of the STC to be changed is when the display intermittently changes the depth from the correct depth to a very shallow depth.
Figure 5.5.1 - STC - Surface Clutter
The STC can be changed from Short, Mid, Long and custom.
5.5.1.0 STC Length
This is the depth range which the STC operates. In custom mode it can be varied from 0 to 1000Ft (60 or 255Ft on previous software versions). In preset mode it’s value is reported in the following table (See Par. 5.5.1.2).
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