Date: Sat, 21 Jun 2014 13:06:19 -0400 From: Daniel Burch <[email protected]> To: [email protected] Subject: [time-nuts] 58503A date code problem Message-ID: <camyugjy7c6lyx7q26zwum40iezmfy5zshrcq_ygda5t4vc3...@mail.gmail.com> Content-Type: text/plain; charset=UTF-8
Hi All, I have a HP/Symm 58530A that has the correct time, but date keeps defaulting to 1994, Nov, 4 after GPS Lock. The pre-lock is 1996, so I do see a change when it locks, just to the wrong date.....time is exactly correct and tracks. Any ideas? Thanks! db -------------------------- It would seem likely that this could become an ongoing problem. I don't know what GPS module is used in the 58503A, but last August it was the turn of the Z3815 thanks to the onboard Furuno GT74. A pair of 1999 Time and Frequency Solutions GPS8 units I own use the same Furuno GPS module and suffered the same fate, and some versions of the Rapco 1804 of similar vintage have also been similarly afflicted. Although in the case of the 1804 it seems to be a Rapco firmware issue rather than anything to do with their Trimble SVeeSix GPS modules as it hasn't so far struck all versions of the same product. The "problem" is the well known and well documented 1024 week rollover issue, exacerbated it would seem by some manufacturers, or individual designers, choosing an arbitrary date for the start of their own 1024 week period, perhaps either an initial production date or firmware compilation date, and then not seeing any need to update that as time went by, probably because they weren't anticipating a near 20 year product life. With the date chosen unlikely to be public knowledge and perhaps just lost in time anyway, the "failure" can come as a surprise to all and sundry, manufacturer included However, if any such manufacturers did have ongoing production of the same module over an extended period, and had the foresight to update the start of their 1024 week period at either regular or irregular intervals as production continued, then we also face the interesting possibilty of successively failing batches of the same product rather than all showing up in one go. Regards Nigel GM8PZR _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
