GP1670F_1870F Operator's Manual - Furuno USA

7.17 FISH FINDER Menu7. FISH FINDER OPERATIONSThis section provides the descriptions for the items in the [FISH FINDER] menu thathave not been mentioned previously.Scroll[BACKGROUND COLOR]: Select the background color, among black, dark blue,light blue, white and monochrome (echoes appear in tones of gray.)[COLOR BAR]: Turn the color bar on or off.[BOTTOM RANGE SHIFT AREA]: Select the area where to show the bottom echo,when Auto Range is active. For example, setting 75% would place the bottom echo ata position equivalent to 75% from the top of the display.[ZERO LINE REJECTION]: Turn the zero line (transmission line) on or off. Whenturned on, the transmission line disappears, which allows you to see fish echoes nearthe surface clearly. The length of the transmission line changes with transducer usedand installation characteristics. If the width of the transmission line is 4.5 ft (default value)or more, set the transmission line width with [ZERO LINE RANGE].[ZERO LINE RANGE]: This feature adjusts the transmission line so that the line disappearswhen the menu item [ZERO LINE REJECTION] is turned on. For a long tail,increase the value. If the transmission line does not disappear, lower the TX power.[FULL SCREEN GAIN CONTROL]: The gain setting can be applied to only new echoesor new and existing echoes. Turn this feature on to get the gain setting applied toboth new and existing echoes. The advantage of the full screen gain control is that youcan quickly and easily find the right gain setting for your conditions.7-19