[time-nuts] Z3815A date problem fixed?

[Magnus Danielson]

On 24/01/14 11:59, Morris Odell wrote:
> Hi all,
>
> There was some consternation here 5 months ago when Z3815A GPSDOs began
> reporting a date 1024 weeks in the past. This was due to a storage overflow
> condition in the Furuno GPS receiver in the Z3915A. The designers probably
> never anticipated that they would still be in use 20 years later....
> Oscillator discipline was unaffected as the 1 pps was still good.

It's kind of expected that the oscillator discipline works, because all 
what has happen is that the conversion from GPS time to normal time 
(being GPS or UTC) has been unable to unwrap the GPS week number 
properly. It's really a problem with the system than with the receiver.

> Obsessional types like me looked for a solution. There didn't seem to be any
> knowledge out there about reprogramming the receivers so it had to be a
> transplant.

Interesting approach. There is two things one can do: Toss in a small 
PIC/AVR/whatever that modifies the time, or update to a receiver which 
does not have the issue. You can also just completely ignore the fact :)

Cheers,
Magnus