[time-nuts] Thought experiment on a low cost timing board

Poul-Henning Kamp phk at phk.freebsd.dk
Sun Feb 26 02:57:54 EST 2006

In message <13c.25b46209.3132504c at aol.com>, SAIDJACK at aol.com writes:

>Good OCXO's (e.g. MTI) crystals usually age between 3E-09 to 5E-010  per day 
>as per their spec.

They use this for the "O"CXO which is steered by the Rb cell, so they have
a very high feedback frequency, so I think they just live with the steps.

That said, with a decent quality DAC, a step on the upper DAC would not
give an error of more than maybe ten steps on the lower DAC.

>You mentioned there are some discontinuities when the coarse DAC switches  
>(since the coarse and fine dacs have to switch simultaneously I guess to prevent 
> glitches). How bad are these discontinuities/glitches?

I can't see them in my log.

Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
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Never attribute to malice what can adequately be explained by incompetence.

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