Hi Poul, I accidentally replied to only you (and had to repost to the list), so I'm redirecting this thread back to the list.
I have tried smaller gains, but I'll do it again. I'll post back later with a d gain of 1/9 of what it was for those plots. The difference will be obvious on the DAC plot. I did change the differential algorithm since I tried it with low gain, so maybe it'll help. Bob ________________________________ From: Poul-Henning Kamp <p...@phk.freebsd.dk> To: Bob Stewart <b...@evoria.net> Sent: Wednesday, August 27, 2014 2:02 PM Subject: Re: [time-nuts] OCXO Phase Noise Measurement in Primitive Conditions -------- In message <1409165381.1098.yahoomail...@web142702.mail.bf1.yahoo.com>, Bob Ste wart writes: Your PLL (PID) has (far) to high gain: You are yanking the EFC around to every single little wiggle in the GPS signal. The curve relative to the Rb should be very, very straight, any wavyness should be on timescales of at least 20-30 minutes, not within single minutes as your first plot shows it. This is a very common beginners fault: I made it myself too :-) Lower the PID gain, until the DAC/EFC line only wiggles the minimum amount necessary to keep the OCXO from drifting away from the Rb... -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@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. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
