•It is difficult to get fish arches in shallow water as the transducer sonar beam is very narrow near the surface and fish do not stay within the beam long enough to display an arch. Several fish in shallow water tend to display as randomly stacked blocks of pixels.
•Wave motion may result in distorted fish arches
4-4 Gain
Gain (sensitivity) controls the amount of detail displayed on the FISH 4432/4433. Understanding how to set suitable Gain settings is important for optimum performance.
The Navman fishfinder has three gain modes, Cruising, Fishing and Manual.
•Cruising Mode
Use this mode to show only the bottom and large fish.
•Fishing Mode
Use this mode to show as much detail as possible.
•Manual Mode
The gain can be adjusted by the user to compensate for water depth and clarity.
High Gain settings may amplify the normal background noise until it appears as random pixels.
Changing between Cruising, Fishing and Manual
To change between Cruising, Fishing and Manual
1.From any Sonar display, press ENT.
2.Use the
or
cursor keys to highlight mode option, then use the 
cursor key then select desired option from list.
Adjusting Gain and Threshold settings
The gain settings and the threshold settings can be adjusted independently for each frequency (83kHz and 200 kHz).
Use threshold to eliminate colors in the sonar display.
1.From any Sonar display, press ENT.
2.Use the
or
cursor keys to highlight the desired setting, then use the
cursor key to change it.
Note: The Gain mode automatically changes to Manual Gain if the gain or threshold settings are adjusted by the user.
Obtaining the best results
To obtain the best detection capability for both fish and bottom we recommend the use of the Sonar
1.Set the threshold to 0%.
2.Adjust the gain until the threshold line is just to the right of the unwanted noise.
Gain Threshold line
Unwanted signal
Gain line
FISH 4432/4433 Installation and Operation Manual | NAVMAN | 22 |