Furuno CH-270 2-17, 2.11.4 Erasing weak echoes

2. HORIZONTAL MODE

2-172.11.4 Erasing weak echoes

Weak echoes such as interference can be erased from the screen. This is useful when

you want to observe a fish school echo.

1. Press the [MENU] key to open the menu.

2. Press ▲ to choose MENU.

3. Press ◄ or ► to choose COM2.

DELETING TRACK NO

WHITE MARKER OFF

SIG LEVEL OFF

COLOR 16

BKGD COLOR 2

: SELECT : CHANGE MENU: END

MENU COM1 HORZ VERT ES

SHORT-CUT

SYSCOM2

COM 2 menu

4. Press ▲ or ▼ to choose SIG LEVEL.

5. Press ► to open the dialog box.

SIG LEVEL

OFF 114

(OFF, 1-14)

OFF

8-color display: OFF, 1-6

16-color display: OFF, 1-14

Signal level dialog box

6. Press ◄ or ► to choose echo color to erase. Pressing ► erases echoes from weak to

strong in ascending order of strength. You can see which echo color is erased by

watching the color bar.

7. Press the [MENU] key to register your selection and close the menu.

Contents

Main Page i IMPORTANT NOTICES ii SAFETY INSTRUCTIONS WARNING ELECTRICAL SHOCK HAZARD WARNING iii CAUTION TFT LCD CAUTION WARNING LABELS iv TABLE OF CONTENTS v vi FOREWORD Features Usage Precautions ix SYSTEM CONFIGURATION CH-270 (350 stroke) x 1-1 1. OPERATIONAL OVERVIEW 1.1 Control Description 1-2 1.2 Remote Controller 1-3 1.3 Turning the Power On/Off 1.3.1 Power on 1-4 1.3.2 Power off 1-5 1.4 Raising, Lowering the Transducer 1.4.1 Lowering the transducer CAUTION 1.4.2 Raising the transducer 1. OPERATIONAL OVERVIEW 1-6 1.5 Choosing a Display NAV D ATA Key Key VERTICAL SCAN ECHO SOUNDER 1.6 Adjusting Screen Brilliance, Panel Dimmer 1.7 Adjusting the Gain 1-8 1.8 Basic Menu Operation 2-1 2. HORIZONTAL MODE 2.1 Operational Overview The figure below shows the typical horizontal mode operating sequence. Control unit 2. HORIZONTAL MO DE 2.2 Typical Horizontal Mode Display 2-3 2.3 Choosing the Range 2-4 2.4 Choosing Sector Width 2-5 2.5 Choosing Train Center 2-6 2.6 Choosing the Tilt Angle 2.6.1 Choosing the tilt angle 2-7 2.6.2 Relation between tilt angle and echo ): 2-8 2.6.3 Tilt angle for surface fish 2. HORIZONTAL MODE 2-9 2.6.4 Suitable tilt angle Tilt angle and beam coverage (frequency 180 kHz, vertical beamwidth 8 Vertical width of sonar beam Depth (m) 2.7 Choosing the Training Speed 2.8 Finding Echo Position with the Cursor 2-11 2.9 Event Marker 2.9.1 Inscribing the event marker 2-12 2.9.2 Deleting all event markers 2.10 Depth and Horizontal Range Markers 2-13 2.11 Adjusting the Picture 2.11.1 Suppressing bottom and surface reflections 2-14 2.11.2 Suppressing bottom tail 2.11.3 Displaying weak echoes clearly 2-15 2-16 2-17 2.11.4 Erasing weak echoes 2. HORIZONTAL MO DE 2-18 2.11.5 Enlarging fish echoes (horizontal expansion display) Horizontal expansion display 2-19 2.12 Target Lock 2.12.1 Choosi ng target lock mode 2.12.2 Manual reverse mode 2-20 2.12.3 Position mode 2-21 2.12.4 Echo mode 2-22 2-23 2.13 Horizontal Menu Overview 2-24 2-25 2.14 Interpreting the Horizontal Display 2.14.1 How the horizontal mode picture is painted 2-26 2.14.2 Sample echo displays 2. HORIZONTAL MODE 2-27 Fish schools Fish schools 2-28 Sea surface reflections 2-29 Sidelobe echo (false echo) 2-30 2.14.3 Combination display examples 2-31 2-32 2-33 2-34 3-1 1. 11. 3. VERTICAL SCAN MODE 3.1 Operational Overview The figure below shows the typical vertical scan mode operating sequence. Control unit 3. VERTICAL SCAN MODE 3.2 Displaying Vertical Scan Mode Display 3.2.1 Typical vertical scan mode display Press the key to show the vertical scan mode displ ay. 35 m 12.3 C 3-3 3.2.2 How the vertical scan picture is painted 3. VERTICAL SCAN MODE 3-4 3.2.3 Horizontal/vertical scan display Press the key to display the horizontal/verti c al scan display. 3-5 . 3-6 3.3 Choosing the Range 3.4 Choosing Train Center 3-7 3.5 Choosing Display Sector 3-8 3.6 Choosing Sector Center 3-9 3.7 Choosing the Tilt Speed 3.8 Finding Echo Position with the Cursor 3-10 3.9 Event Marker 3.9.1 Entering an event marker 3-11 3.9.2 Deleting all event markers 3.10 Depth and Horizontal Range Markers 3-12 3.11 Adjusting the Picture 3.11.1 Displaying weak echoes clearly 3-13 3-14 3.11.2 Suppressing noise and interference 3.11.3 Gain adjustment 3-15 3.11.4 Resolution color 3.11.5 Suppressing clutter Page 3-17 3.12 Interpreting the Vertical Scan Display 3.12.1 Sample echo displays 3-18 4-1 4. ECHO SOUNDER MODE 4.1 Operational Overview The figure below shows the typical echo sounder mode operating sequence. Control unit 4. ECHO SOUNDER MODE 4.2 Typical Echo Sounder Display Press the key to display the echo sounder picture. 6.5 m 12. 3C Typical echo sounder display 4.3 Choosing the Range 4-4 4.4 Train Direction 4.5 Choosing Tilt Angle 4.6 Choosing Picture Advance Speed 4-5 4.7 Measuring Range by Cursor 4.8 Event Marker 4-6 4.8.1 Inscribing the event marker 4.8.2 Deleting all event markers 4-7 4.9 Range Marker 4-8 4.10 Adjusting the Picture 4.10.1 Displaying weak echoes clearly 4-9 4-10 4.10.2 Finding echo strength (A-scope display) 4-11 4.10.3 Gain adjustment 4.10.4 Resolution color Page 5-1 5. MENU OPERATION 5.1 COM1 Menu 5.1.1 Displaying the COM1 menu 5.1.2 COM1 menu description 5-2 5.2 COM2 Menu 5.2.1 Displaying the COM2 menu 5.2.2 COM2 menu description 5-3 5.3 Short-cut Menu, Preset Menu 5.3.1 Choosing short-cut or preset 5. MENU OPERATION 5-4 System menu 5. SYSTEM SETTING is highlighted; press to open the SYSTEM SETTING m enu. 5-5 5.3.2 Changing setting of preset key 5-6 5.3.3 Changing setting of short-cut key 5-7 VERTICAL SEARCH FUNCTION 5-8 5.4 SYSTEM Menu 5.4.1 Displaying the SYSTEM menu 5-9 5.4.2 SYSTEM SETTING 1 menu description 5-10 5-11 5.4.3 SYSTEM SETTING 2 menu description 5-12 5-13 5.4.4 Sonar (horizontal) mode range settings 5-14 5.4.5 Vertical scan mode range settings 5-15 5.4.6 Echo sounder mode range settings 5-16 5.4.7 Track range settings 5-17 5.4.8 Color palette 5-18 5.4.9 Language 5.4.10 System backup 5.4.11 Loading backup data 5-19 5.4.12 Transducer frequency adjustment 5.4.13 Demonstration mode 5-20 5.4.14 Restoring all default settings 6-1 6. MAINTENANCE, TROUBLESHOOTING WARNING 6.1 Preventive Maintenance 6.2 Cleaning the Equipment WARNING 6-3 6.4 Transducer Maintenance CAUTION 6.5 Fuse Replacement CAUTION 6-4 6.6 Troubleshooting 6-5 6.7 Error Messages 6. MAINTENANCE, TROUBLESHOOTING 6-6 6.8 Diagnostics * Test results To quit the test, press the [MENU] key three times. 6-7 6-8 6.9 Test Pattern M-1 MENU TREE MENU TREE M-2 SP-1 SPECIFICATIONS 1. GENERAL 2. DISPLAY UNIT/ CONTROL UNIT 3. HULL UNIT SP-2 4. I/O INTERFACE 5. POWER SUPPLY 6. ENVIRONMENTAL CONDITIONS 7. COATING COLOR INDEX M L I H IN-2 N 1-4 ) X