User manual FURUNO FSV-30 REFERENCE GUIDE

[. . . ] COLOR SCANNING SONAR FSV-30 The paper used in this manual is elemental chlorine free. FURUNO Authorized Distributor/Dealer 9-52 Ashihara-cho, Nishinomiya 662-8580, JAPAN Telephone : Fax : 0798-65-2111 0798-65-4200 All rights reserved. Printed in Japan FIRST EDITION : DEC. OME-13230 ( TATA ) FSV-30 *00014857203* *00014857203* *00014857203* *OME13230D10* *OME13230D10* *OME13230D10* SAFETY INSTRUCTIONS DANGER Keep away from moving shaft of the hull unit. A heater can melt the equipment's power cord, which can cause fire or electrical shock. Use the proper fuse. WARNING ELECTRICAL SHOCK HAZARD Do not open the equipment. [. . . ] The color of the mass shows the density of fish schools on the sonar beam. To find distribution and center point of a fish school, try several different tilt angles. (A) Sea surface fish Tilt angle: 0° to 10° Fish school Bottom echo not displayed because of decreased tilt angle. Sea surface reflections are present. Sea surface reflections (B) Midwater, bottom fish Tilt angle: 30° or more Fish echo which appears before bottom can be detected. Bottom Fish school Large midwater fish school is present. Tilt angle: 0° to 20° Fish echo which appears together with or after bottom can be detected. Fish school Bottom When the tilt angle is shallow, the reflection echo from bottom is weak and the fish echo which appears from bottom is easy to find. Fish schools 2-47 2. HORIZONTAL MODE Sea surface reflections To reduce sea surface reflections, set the tilt angle to 5° or higher, so the upper edge of the sonar beam does not hit the sea surface, or adjust TVG. When a decreased tilt angle is used, sea surface reflections cover a large area as illustrated below. Sea surface Tilt angle indication Tilt: 0° 18° Sea surface reflections Sea surface Tilt: 5-6° 18° Sea surface reflections Wake A wake produced by own ship or another ship can be a strong reflecting object when a decreased tilt angle is used. As the wake appears as a thick continuous line, it can be easily distinguished from a fish school. A wake contains many air bubbles which attenuate ultrasonic energy, making it difficult to sound beyond the wake. Other ship Own ship Own ship's screw noise Wake produced by other ship Own ship's screw noise Own ship's wake (produced when own ship turned) Wake 2-48 2. HORIZONTAL MODE Sidelobe echoes (false echoes) An ultrasonic wave is emitted only in the direction set by the [TILT] control, however there are some emissions outside the main beam. The energy of the sidelobe is fairly weak but when the water is comparatively shallow and the bottom is rocky and hard, strong signals are detected by the sidelobe. These are represented on the display as a false echo as shown below. Mainlobe echo Sidelobe Sidelobe echo Mainlobe The bottom echo detected by sidelobe appears at a certain tilt angle when the sidelobe points vertically. Also, poor soundome projection may result in a similar false echo. Sidelobe echoes Noise and interference When the fishing ground is crowded with many fishing boats, the sonar is subject to interference from ultrasonic equipment (echo sounder or sonar) on other boats as well as those on own ship. For instance, interference from the sonar operated on other boats will show itself on the display as in (A) in the figure below. This interference can be suppressed by changing the TX INTERVAL on the H-SCAN SETTING menu. Noise from marine life shows itself on the displays as in (B) in the figure below. This type of noise can be suppressed with the interference rejector on the H-SCAN SETTING menu. (A) Inteference from other sonars (yours or other's) (B) Interference from marine life Noise and interference 2-49 2. HORIZONTAL MODE The page is intentionally left blank. 2-50 3. 3. 1 VERTICAL MODE Basic Operating Procedure 4. Select vertical 1 or vertical 2 display. 2. Lower transducer. 3. Select range. Set vertical bearing mark to display in vertical display. 5. 9. Press to select vertical display if necessary. Control unit 3-1 3. VERTICAL MODE 3. 2 3. 2. 1 Vertical Mode Concept Overview The vertical mode shows a vertical section of the horizontal display selected with the vertical bearing mark. The figure below illustrates the concept of the vertical mode, in comparison with the horizontal mode. The vertical mode helps you keep fast moving fish such as bonito and tuna within the sonar beam. Horizontal Mode Vertical Mode H-Beam V- Beam Vertical mode concept 3. 2. 2 Setting the vertical display 1. [. . . ] Use these functions under deep understanding. Horizontal mode "H2" setting. Horizontal H2 settings are the same setting as the horizontal H1 except the settings of FREQ SHIFT. In order to avoid the interference between H1 and H2 signals with multi-transmission mode, the frequency is shifted down to 22. 4 kHz (-16). When use the individual transmission mode, shifting frequency is not required. Vertical mode "V" setting. All settings, P1 to P10, are common settings except the setting of the frequency shift. Smooth the upper edge of bottom echo in order to distinguish the bottom fish. [. . . ]