[time-nuts] Jitter Test on Dividers
jmiles at pop.net
Sun Sep 20 22:01:54 UTC 2009
Interesting! 500 picoseconds is a lot of drift. Can you try 74AC390s as
-- john, KE5FX
> -----Original Message-----
> From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com]On
> Behalf Of Brian Kirby
> Sent: Sunday, September 20, 2009 2:19 PM
> To: precise time
> Subject: [time-nuts] Jitter Test on Dividers
> I ran a 24 hour test on the async dividers (74HC390s) that Tom Clark
> designed and they basically have a triangular peak to peak jitter of 500
> picoseconds over 22 minutes. The baseline drift started at reference
> 0 ns and made a negative parabola that dipped to -750 picoseconds
> and then returned back to the reference, over 24 hours.
> I check the TADD-2s (two units for seperate 12 hour test) and they
> appeared to not have any drift. One unit showed a standard deviation
> of 34 picoseconds, The other unit showed 20 picoseconds.
> The time interval counter is a HP5370B, which tested at 20
> picoseconds jitter.
> Brian Kirby - KD4FM
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