Garmin GPSMAP 392, 398, 492, 498 Owner's Manual

Also see for GPSMAP 392, 398, 492, 498: Quick reference guide Specifications

Contents

GPSMAP 392/398/492/498 Owner’s Manual 87APPENDIX > INSTALLING THE GPSMAP 492/498 EXTERNAL GPS ANTENNAInstalling the GPSMAP 492/498 ExternalGPS AntennaThe GPSMAP 492/498 with external antenna must be properlyinstalled according to the following instructions to get thebest possible performance. To complete the external antennainstallation, you need the appropriate fasteners and a 1" x 14-threadmarine antenna mount available at most marine dealers.The GPSMAP 492/498 with internal antennas do not require thisinstallation. To acquire satellites, install the unit with a clear viewof the sky.Mounting the GPS Antenna(External Antenna Units Only)The antenna should be mounted in a location that has a clear,unobstructed view of the sky in all directions to ensure the bestreception. Avoid mounting the antenna where it is shaded by theboat’s superstructure, a radome antenna, or mast. Sailboat usersshould avoid mounting the antenna high on the mast to preventinaccurate speed readings caused by excessive heeling. Mostmarine VHF and LORAN antennas should not seriously degradethe GPS antenna’s reception. Never paint the antenna or clean itwith harsh solvents.Suggested locations for mounting the external antenna.The Garmin antenna screws directly onto any standard 1" x 14-thread antenna mount. If you need to raise the antenna to avoidshading, try using a 1" x 14-thread extension mast available at mostmarine dealers.NOTE: It is possible to routethe coaxial cable either through,or outside the antenna mount. Itis possible to remove the BNCconnector on the coaxial cableand the coaxial cable shortenedto ease installation, however,doing so voids the antennawarranty. If the BNC connectoris removed, it must be replacedwith a new solder-on or crimpBNC connector.