[time-nuts] Z3801A leap second bug coming up

Tom Van Baak tvb at leapsecond.com
Thu Sep 29 12:22:06 EDT 2005


I'll be logging a 58503B and a Z3801A tomorrow
just to check. Please do the same so we can
compare notes.

As I recall it self-corrects the prediction within a
second and there is no error in either the 1 PPS
or the 10 MHz outputs. There is no problem with
any other GPSDO; just the old Oncore based


----- Original Message ----- 
From: "Tim Shoppa" <shoppa at trailing-edge.com>
To: <time-nuts at febo.com>
Sent: Thursday, September 29, 2005 08:57
Subject: [time-nuts] Z3801A leap second bug coming up

> As discussed a while back here, the Z3801A seems to believe that
> on the evening of Sep 30th there will be a leap second.  Some folks
> made comments about the last time this bug surfaced in the 90's.  What
> happened at the moment of the leap second, did the Z3801A's time stamp
> response to :PTIME:TCODE? go out of whack for a second, a few hours,
> until a power-cycle/reboot, something else?
> It seems likely to me that after a reboot everything would be OK, but
> I'd like to avoid this if possible.  (Reasoning for why everything
> should be OK after the reboot: the Oncore inside the Z3801A will
> figure out a leap second is coming, but it will have the correct
> GPS-UTC offset and will now correctly assign the leap second to Dec 31.)
> I would be surprised if OCXO discipline was disrupted by the not-real
> leap second but maybe it's possible.
> Tim.

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