Important information to those of you that have a Furuno GP-50, GP-50 mk 2, GP-70, GP-70 mk 2, GP-500 mk 2 or Felcom 11.
We thank you very much for your trust and continued support. This is to notify you that a GPS week number rollover may occur to certain GPS receivers that we supply. We would like to take this opportunity to inform you of the countermeasures that should be taken to remedy this situation.
On the 12th of December 2010, the date information contained within certain GPS receivers (listed abowe) will roll back to the 28th of April 1991. This is called "GPS week number rollover".
Although this does not affect position data, the date information on which the position is computed will be incorrect (the time information is not affected). Namely, if the GPS receiver is used only for obtaining position data, this will not pose a problem at all, but if the date information is utilized or the GPS receiver is integrated in the data-collecting system, a problem will arise due to incorrect date information.Why GPS counts week number rollover occurs:The GPS week number rollover occurs every 1,024 weeks — about once every 20 years. The GPS system calculates date by counting the number of weeks in the cycle of 1,023 weeks. On the eve of the beginning of the1,024th week, the GPS week "counter" will roll back to zero weeks (Time Scale Origin). As a result , some GPS receivers may display inaccurate date information.
Contact your Furuno dealer and ask for a exchange price.