[time-nuts] Timing receivers' observations of leap second
james.h.maynard at usa.net
Sat Dec 31 19:53:12 EST 2005
Here in Salem, Oregon, USA, I observed two timing displays at the moment
of the leap second: the display of an Ultralink Model 333 WWVB Decoder
and that of some PC software from CNS Systems, Inc. I was also listening
to the audio of the HF time and frequency stations, WWV and WWVH, at
Ultralink Model 333:
My UltraLink model 333 WWVB receiver has not yet recorded the leap
second, probably because its antenna is in too noisy a location to
receive WWVB's 60 kHz signal at this time of day. The display still
indicates that a leap second is pending, and it still indicates an
offset from UTC to UT1 of -0.6 s.
Apparently the Model 333 WWVB receiver's software does not apply the
leap second to its display at the scheduled time, althouth it does know
that a leap second is pending. It seems that this software does not
apply the leap second until it actually receives a signal from WWVB with
the newly adjusted UTC timescale.
The SynTac32 software (from CNS Systems, Inc.) that displays the output
of my Motorola M12+ timing receiver waited a couple of seconds after the
leap second occurred before displaying the correct time, including the
leap second adjustment.
My guess is that this display software, like that in the WWVB receiver,
does not apply the leap second adjustment at the scheduled time, but
waits until it receives messages from the M12+ that reflect the newly
adjusted UTC time scale.
The Motorola M12+ itself, however, as indicated in the posting from
Christopher Hover <ch at murgatroid.com>, does apply the leap second at the
Salem, Oregon, USA
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