[time-nuts] week 1024 roll over

Glenn Little WB4UIV glennmaillist at bellsouth.net
Fri Apr 18 01:19:46 EDT 2008

I recently bought a Datum GPS Time/frequency System 9390-5593. When I 
enter date, time and location, it fails to indicate GPS lock. It is 
indicating GPS week 451, when the week is really 1475. It is also 
indicating that the day is 246. I highly suspect that the receiver 
has firmware that needs to be updated.
I have not disassembled the equipment far enough to verify the type 
of GPS engine installed. Does anyone know what GPS engine is 
installed in this equipment?
Will the 1024 week rollover cause the receiver not to lock, I suspect 
that the receiver will not lock as it has incorrect date?
Can I change the engine to something that has correct firmware?
Does the receiver output NMEA 0183 data or something unique?

I contacted Symmetricom as they bought Datum. They say this product 
was out of support prior to them buying Datum. I requested the price 
of a manual. They will sell me one, if they have one to copy, for a 
mere $250.00. I suspect that they do not have a firmware update that 
they will release for a reasonable cost. This is a hobby, not a 
business for me.

Any help or advice? Possibly just scrap this and use the Rb standard?


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