User manual FURUNO CH-37 OPERATORS MANUAL

[. . . ] COLOR SECTOR SCANNING SONAR MODEL CH-37 Your Local Agent/Dealer 9-52 Ashihara-cho, Nishinomiya, Japan Telephone : Telefax : 0798-65-2111 0798-65-4200 All rights reserved. Printed in Japan FIRST EDITION : JUL. OME-13030 ( TENI ) CH-37 *00080821101* *00080821101* *00080821101* *OME13030E00* *OME13030E00* *OME13030E00* SAFETY INSTRUCTIONS WARNING ELECTRICAL SHOCK HAZARD Do not open the equipment. Only qualified personnel should work inside the equipment. Immediately turn off the power at the switchboard if water leaks into the equipment or something is dropped in the equipment. [. . . ] Suppresses noise which covers the whole screen. Suppresses interfernce from sonar of other ship or noise from electrical machinery onboard own ship. The fractions the number of scan lines produced per transmission. Select "LOG" or "LINEAR" according to amplifier of echo sounder. LINEAR: FCV-382, 782, 271 LOG: FCV-291, 292. COLOR 2. 17 Turning Trackline Plotting On/Off With navigation data input, the CH-37 can plot ship's track on the sonar mode display. The track itself can be turned on/off with the TRACK key. 2-17 2. 18 Interpreting the Display This section provides the information necessary for interpreting the display. How the picture is painted The wide sounding beam is emitted from the soundome at a certain tilt angle (see hatched area in the figure below). The information (target echoes) obtained by this beam is displayed in 45° sector of the screen. Thus, all directions around the boat are s ounded in 8 times of transmissions. Note: When the "FAST SCAN" is switched off, the equipment operates in a narrow sounding beam. Then, the echoes appear on a 6° sector in each transmission, so 60 times of transmissions are required to complete full 360° picture (6° x 60 = 360°). However, since transmission power is concentrated into the narrow sounding beam, a superior detection range is obtained. Furthermore, since the bottom contour is painted distinctly, bottom fish detection may become easier. Sounding Beam Freq: 60 kHz Screen Display TX Tilt Sounding Beam RX 16° 13° 60°/16° 13° 45°* Tilt: When the narrow sounding beam (6-degree step operation) is selected, 60 transmissions are required to complete the full circle detection. Figure 2-16 How the picture is painted 2-18 Bottom echoes When the tilt angle is widened, the bottom echo illustrated below will appear on the display. When the tilt is narrowed, the bottom trace becomes wider and weaker. By observing the bottom condition on the display, the skipper can prevent net damage. (A) Flat bottom Tilt angle: 10° to 15° Narrow tilt angle Only half of vertical beam width captures the bottom. (B) Flat bottom Tilt angle: 20° or more (C) Sloping bottom Tilt angle: 20° or more Bottom is displayed narrower and in stronger colors when compared to (A). Shallow bottom is displayed in a strong color and with a short tail. Bottom The deeper bottom echo is displayed in a weak color and with a long tail. Figure 2-17 Bottom echoes 2-19 Fish schools A fish school appears as a mass of echoes on the screen. 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: -5° to 10° Bottom echo not displayed because of narrow tilt angle. Sea surface reflections are present. Fish school 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, he reflection echo from bottom is weak and the fish echo which appears from bottom is easy to find. Figure 2-18 Fish schools 2-20 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 narrow tilt angle is used, sea surface reflections cover a large area as illustrated below. Sea surface Tilt angle indication 15° Sea surface reflections Sea surface 15° Figure 2-19 Sea surface reflections Wake A wake produced by own ship or another ship can be a strong reflecting object when a narrow tilt angle is used. As the wake appears as a thick continuous line, it can be easily distinguished from a fish school. [. . . ] Note: Readjustment of TVG is required whenever the GAIN control is adjusted. MENU TX RATE : SONAR : 10 BOTTOM/3D SHORT B E/S TX PULSE LENGTH : LONG TX OUTPUT POWER : A C (MAX) 0 10 0 10 LEVEL TIME TVG Somewhat strange color BRILL control set too low. Increase the brightness. 0 10 BRILL (Continued on next page) 7-9 Symptom Color partially irregular Magnet is near the screen. Check This symptom occurs if equipment which contains a magnet (loudespeaker, etc. ) is placed near the screen. Check to see if the degaussing circuit is turned off on the SYSTEM SETTING menu. Note: If not cleared, consult with electronics technician. [. . . ]