GP1670F_1870F Operator's Manual - Furuno USA

7. FISH FINDER OPERATIONS[FISH FINDER SETUP]: The [FISH FINDER SETUP] sub menu provides the followingfeatures.ScrollItem[TRANSMISSION][TRANSMISSION POWER][TRANSDUCER][TRANSMIT RATE][50 kHz ECHO OFFSET],[200 kHz ECHO OFFSET]Turn transmission on or off.FunctionSet the transmission power, [High] or [Low]. Interferencemay appear on the screen when an echo sounderhaving the same frequency as your own is being operatedin the vicinity of your boat. In this case, select lowpower and contact the other vessel to request them to reducetheir TX power.Select the transducer used. If you use the optional triducer525STID-MSD or 525STID-PWD, you do not need toselect the transducer.Change pulse repetition rate. Normally, the highest rate(20) is used. When in shallow waters second re-flectionechoes may appear between the surface and actual bottomecho. In this case, lower the TX transmit. The [[Auto]]setting automatically adjusts the frequency and pulselength with depth.The echo offset feature compensates for too weak or toostrong echo level. If the on-screen echo level appears tobe too weak or too strong and the level cannot be adjustedsatisfactorily with the gain controls, apply an offset tocorrect the level.7-20