GME G142CFD User Manual
Page 21

PA G E 2 2
I N S T R U C T I O N M A N UA L
G - C O M B O
3-5-5 Gain
The gain menu
The gain is a signal strength received from the transducer, the 
threshold is the level of ultrasonic signal that is ignored 
by a set value. 
When you use the manual mode and threshold, the values of 
gain and threshold need to be set very carefully. 
In the Gain window, you can set for a gain mode and 
threshold. 
To change a value
1 Press MENU, select Gain.
2 Select a mode.
3 If you select the Manual mode, adjust each frequency gain
value by pressing or . If you select the Auto mode, it 
will be changed to manual mode if you change the values 
of frequency value. 
3-5-6 Sonar window display
Five sonar display windows are available and each display 
window has unique characteristics. Select a display window 
depending on your needs. The default display is No split. 
To change a Sonar display window in the sonar 
window:
1 Press MENU, select Window mode.
2 Select the desired sonar display.
No split: Display Sonar history at a given frequency (50 or 
200 kHz) (see section 3-5-7).
Split zoom: This mode expands a chosen area of the normal 
picture in full vertical size on the left-hand side of the window. 
Full screen zoom: Display a zoomed section on full screen 
(see section 3-5-8).
Split bottom: Display Sonar history and a bottom trace focus 
in a zoomed section (see section 3-5-9).
Split 50/200: Display the 50 kHz sonar history on the left 
and the 200 kHz sonar history on the right. This display is 
useful for comparing the same history with two different 
frequencies. (see section 3-5-10).
Split A-Scope: Display Sonar history and echo strength (see 
section 3-5-11).
You can change the split ratio if the window is split.
1 Press MENU and select Window split.
2 Press or to adjust the ratio.
3 Press ENT.
3-5-7 No split
No split window displays a sonar history at a given frequency 
(50 or 200 kHz).
Low Frequency (50 kHz)
The 50 kHz frequency is ideal for detecting the wider area 
which means low frequency is useful for general detection and 
judging bottom conditions. Also good for deeper water. 
High Frequency (200 kHz)
The 200 kHz frequency will provide a better resolution which 
means it is ideal for the observation of fish or fish schools. 
Also good for shallow water.
To set a frequency for this display:
1 Press MENU.
2 Select Frequency
3 Select a desired frequency
You can also review old sonar records, press and to 
review the history. To return to current scanning, press ESC 
