Chapter 5 - Understanding Position CoordinatesPage 5-10 961 Operations and Reference Manual Rev. DUsing Phantom loran to determine positionWhat is Phantomloran?The 961’s Phantom loran feature is designed for those 961users who’ve previously compiled lists of fishing spots or otherlocations as loran TDs, and who are now using the 961 as aGPS-only navigator. The 961 mathematically converts GPS lat/lon coordinates to loran TDs—in real time as you navi-gate—enabling you to display your current position as TDs.When entering new waypoints, the 961 lets you enter way-point coordinates as loran TDs, usually by first pressing a LL/TDS key, which switches the display of coordinates betweenlat/lon and loran TDs.The 961 may be used to simulate full operation of a loranreceiver. Position coordinates may be displayed as TDs, and allnavigation functions may be used as if the unit were actuallyreceiving loran signals. Remember, however, that these calcu-lated TDs won’t exactly match the positions of previouslyrecorded TD coordinates that you obtained from actual loransignals. In most areas, TD errors shouldn’t exceed one micro-second; however, larger errors are possible in areas for whichthe 961 doesn’t contain accurate factory-programmed ASF cor-rection points.Selecting Phantomloran TDsThe 961 gives you the option to display position coordinatesas Phantom loran TDs. To display TDs on the CHART screenINFO BARs (and the CURSOR INFO BAR), you must turn onloran TDs at the CHART SETUP screen. The 961’s default set-ting is ON.1. Press the STAR key twice to access the SETUP MENUscreen.2. Press the CHART SETUP key.3. Press the CURSOR PAD down to highlight the LORANINFO BARS field, then press the EDIT key.4. Press the CURSOR PAD right to select ON, then press theACCEPT key.
