[time-nuts] Jitter Test on Dividers

[John Miles]

Interesting!  500 picoseconds is a lot of drift.  Can you try 74AC390s as
well?

-- 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
>
>
>