[time-nuts] M12+T First Light

Poul-Henning Kamp phk at phk.freebsd.dk
Sat Apr 16 07:03:48 EDT 2005

In message <42604CE5.1040107 at pacific.net>, Brooke Clarke writes:
>To use an astronomical term "First Light" meaning my first use of
>the M12+T GPS Timing receiver.  WOW!!!!
>The manual description of the @@Hn command shows -128 to +127 ns
>as the range for the sawtooth error.  On the 8 channel unit I think
>the actual sawtooth error was around + and - 50 ns.
>I looked at the @@Hn data stream in TAC32 and saw numbers in the
>mid teens, much lower than the 8 chan sawtooth error.  I'm not sure
>if this is typical, or maybe I was just lucky.  I have the El mask
>set to 50 degrees and Time RAIM turned off.

The clock generating the 1PPS is twice as fast in the M12 as on the
older Oncores, so the jitter is also only half.

Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.

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