Furuno CH-500, Руководство оператора

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3. VERTICAL SCAN MODE
3-4
3.4 How to Toggle Full/Half Range Scans
You can alternate the scanned area between full-range scan and half-range scan with
the FULL/HALF SECTOR key .
For detailed instructions on sectors and how to use the FULL/HALF SECTOR key,
see section 1.13.2.
3.5 How to Select the Training Speed
The training speed chooses how fast the transducer scans the display sector. Two
choices are available, 3° (normal speed, default setting) and 6° (high speed).
To change the training speed at any time, press the Train Speed button ( ).
With each press of the button, the train speed switches between 3° and 6°, and the
scan speed is indicated at the top-center of the echo display area.
3.6 How to Adjust the Picture
Echoes from targets (such as the bottom or a fish) return to the transducer in order of
the distance to them, and when their intensities are compared at the transducer face,
those from nearer targets are generally stronger when their reflecting properties are
nearly equal.
If these echoes are displayed directly on the screen, the size of the displayed echo
from the same school of fish may change with distance, making it difficult to judge the
actual size of the school of fish.
To overcome this inconvenience, use the TVG function. It compensates for propaga-
tion loss of sound in water: amplification of echoes on short range is suppressed and
gradually increased as range increases, so that similar targets are displayed in similar
intensities irrespective of the ranges to them.
The TVG also functions to suppress unwanted echoes and noise which appears in a
certain range area on the screen.
How to adjust the TVG for vertical scan mode
1. Press the MENU key to open the menu.
2. Press
S
to select the menu bar.
3. Press
X
or
W
to select [VERT].