Onwa KF-667 - Manual (Page 18)

2.9 Measuring Depth to a Fish School
The VRM (Variable Range Marker) functions to measure the depth to fish schools or other echo.
1.Press[ ]or[ ]to place the VRM on an echo.
2.Read the VRM range just above the VRM.
2.10 A-scope Display
This display shows echoes at each transmission with amplitudes and tone proportional to their
intensities, on the right 1/4 of the screen. It is useful for estimating the kind of fish school and
bottom composition. To turn the A-scope display on or off press the [SIG LEV] and [ALARM]
keys together.
Normal
display
A-scope
display
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