User manual LOWRANCE X-20A

[. . . ] X-20A INSTALLATION AND OPERATION INSTRUCTIONS ·LOWRANCE ELECTRONICS, INC. LITHO IN U. S. A. 988-0105-36 12000 E. SKELLY DR. , TULSA, OK 74128 PDF compression, OCR, web-optimization with CVISION's PdfCompressor PDF compression, OCR, web-optimization with CVISION's PdfCompressor TABLE OF CONTENTS INTRODUCTION INSTALLATION POWER CONNECTIONS KEYBOARD BASICS OPERATION SENSITIVITY CHARTSPEED RANGE ZOOM DIGITAL FISH I. D. FEATURE 1 1 2 3 5 5 7 8 8 9 10 11 11 AUTO ALARMS CHARTALARM FISH ALARM SPEAKER LIGHT MODE SIMULATOR TRANSDUCERS AND CONE ANGLES SIGNAL INTERPRETATION FISH ARCHES WATER TEMPERATURE AND THERMOCLINES SURVEYING A LAKE BAIT FISH SPECIFICATION SERVICEINFORMATION TROUBLESHOOTING 12 13 13 13 14 16 17 18 18 20 21 22 22 23 23 Copyright © 1991, Lowrance Electronics, Inc. All screens in this manual are simulated. 26 PDF compression, OCR, web-optimization with CVISION's PdfCompressor 4. [. . . ] You can leave the sensitivity in the automatic mode or manually adjust it to suit conditions. You mayneedto increase the sensitivityto showfish symbolswhen the unit is in automatic. The letters 'SENS"will flash on theright side of thedisplay. To increase the sensitivity, press and hold the up arrow key until the sensitivity is at the desired level. After you've finishedsetting thesensitivity level, the letters "SENS" and thesensitivity bar will disappear after eight seconds. 83° 7B° SURFACE LAVER ABSORBS HEAT FROM THESUN 770 EPILIMNION 760 75° THERMOCLINE SENSITIVITY BAR Most PRODUCTIVE ZONEFOR FISHING VARIES DEPTh IN DUETO WIND, 68° 56° 50° 47° 5 PDF compression, 20OCR, web-optimization with CVISION's PdfCompressor With highsensitivity settings, a secondbottomecho (second echo) may appear. It's causedby the returning signal reflecting off the surface of thewater. Then it makes a second tripto thebottom and back again. . -- BOAT'S DIRECTION OF TRAVEL U SENSrnVITY BAR N 14. : I- AUTO SENS RANGE 20 4L FISH ID EU . . A ·: U . C . B Remember, when the unit's automatic feature is on, the receiver's sensitivity automatically adjuststo the surrounding conditions. The microcomputerplaces it at a level slightly above theminimum required to pick up the bottom signal. However, it's possible to changethe sensitivity level whilethe unitis in automatic. This maybe desirable ifthesensitivity level is not high enoughto showfish or other small detail. The unit will increase the sensitivity to pick up thebottomsignal, then add in the level you programmed. · To adjustthe sensitivitywhile the unit is in automatic, simply press the SENS. Then press either the up arrow key to increase it, or the down arrow key to decrease it. As you press the arrow key, the sensitivity bar moVes up or down, according to the sensitivity level chosen. Very small fish probablywill not arch at all. Medium sized fish will show a partial arch, or a shape similar to an arch if they're in deep water. Largefish will arch, butturn thesensitivity up in deeper waterto seethe arch. Because of water conditions, such as heavy surface clutter, thermoclines, etc. , the sensitivity sometimes cannot be increased enough to get fish arches. One of the best ways to get fish arches is to expand or "zoom" a segment ofthe water. For the best results, turn thesensitivity up as high as possible withoutgetting too muchnoise on the screen. In mediumto deep water, this method should work to display fish arches. You can adjustthe sensitivityin thesamemanner whentheunit is in the manual mode. 6 19 PDF compression, OCR, web-optimization with CVISION's PdfCompressor Both 8 degree and 20 degree transducers give accuratebottom readings, even though the bottom signal is much wider on the 20 degree model. Therest of the signal tells you whetheryou are over rocks, mud, etc. CHARTSPEED SIGNAL INTERPRETATION Your unitgivesan accuratepicture of thebottomthat your boat is passing. A bottom of firm sand, gravel, shell, or hard clay returns a wide bottom signal. If the automatic feature is off and the bottom signal narrows , then it means that you have moved over a mud bottom. [. . . ] The sensitivity and rangeare also adjusted to keep the bottom signal on thescreen at all times. The word "AUTO"will disappear fromthe display, signifying the automatic sensitivity and chart range features are off. This will reset the sensitivity, so you may wish to increase it to see fish or other detail. It converts all echoesto horizontal bars when they first appearon the screen. [. . . ]