Interesting! 500 picoseconds is a lot of drift. Can you try 74AC390s as well?
-- john, KE5FX > -----Original Message----- > From: [email protected] [mailto:[email protected]]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 > > > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
