[time-nuts] no 23:59:60 in TAC32

John Ackermann N8UR jra at febo.com
Sun Jan 1 08:55:19 EST 2006

Bill Beam said the following on 12/31/2005 11:45 PM:
> I have since compared UT+ raw data with TAC32 display
> as follows:
> UT+ raw data             TAC32 display
> 12/31/05 23:59:59     same
> 12/31/05 23:59:60     1/1/06 00:00:00
> 12/31/05 23:59:60     1/1/06 00:00:01
> 1/1/2006 00:00:00     1/1/06 00:00:01
> 1/1/2006 00:00:01     same

Isn't there an extra extra second there?  The UT+ is showing two :60s;
shouldn't there  be only one?

Another thing I haven't dug into, but if the GPS is outputting the time
at the *next* PPS signal, the sentence will appear to be ahead compared
to a display that's attempting to show the *current* time.  Not sure if
that's the case with TAC32.

[ snip ]
> I obtained my data using a Nikon D70 digital still camera
> operated in 'burst' mode taking about three frames per second
> of the computer screen.  Both the TAC32 display and UT+
> raw data are shown together on the screen.

I had my D70 in burst mode pointed at the Spectracom 8170 and HP5065A
clocks; unfortunately, the 8170 took 4 minutes to update, so I didn't
capture the transition.  I did get a couple of shots after the change
showing the 1 second disparity between the two, but it's just not the
same as capturing 23:59:60 (which, alas, the Spectracom never did
display -- it sent :59:59 twice).


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