[time-nuts] How do I measure oscillator frequency using 1pps?

Poul-Henning Kamp phk at phk.freebsd.dk
Sun Jul 10 02:18:40 EDT 2005

In message <42D039CA.6030601 at onetel.net>, David Kirkby writes:
>I've now got
>1) Stanford PRS10 rubidium standard
>2) Motorola M12+ timing GPS receiver with a 1 pps output.
>3) HP 5370B time interval counter.
>I'd like to look at the drift of the rubidium before I try to steer it 
>with the PLL. Can anyone explain how to do this with the 5370B?

M12+ PPS output to "START" input
PRS10 10MHz output to "STOP" input

Measure time intervals.

You will need to normalize for cycle uncertainties, but that should
be pretty straight forward.

If you divide the 10MHz down to 1 MHz or 100kHz you will not have
cycle uncertainties.

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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