I found also that I have a hardware problem. Bert posted recently that he keeps his OCXOs out in the open with at least one inch of free space on all six sides. My chassis badly ignores that, with the OCXO up against the edge of the case. I noticed that the EFC changed and then a bit later the thermistor reading changed and thought, hmmm, the OCXO on the edge of the case is seeing the temp changes first and causing unexpected changes to the loop condition. I've hooked up my thermistor to the PLL controls. Next is to reconfigure my GPSDO box to give the OCXO some room to breathe. I feel like I'm finally getting somewhere with this random noise from the OCXO.
Bob ________________________________ From: Poul-Henning Kamp <p...@phk.freebsd.dk> To: Bob Stewart <b...@evoria.net>; Discussion of precise time and frequency measurement <time-nuts@febo.com> Sent: Thursday, August 28, 2014 1:04 AM Subject: Re: [time-nuts] OCXO Phase Noise Measurement in Primitive Conditions -------- In message <1409175707.2080.yahoomail...@web142706.mail.bf1.yahoo.com>, Bob Ste wart writes: This looks like a step in the right direction. The "correct" allan plot will have a clearly visible horizontal segment somewhere in the 100-10000 second range (depending on OCXO quality). This is where the GPS long-term stability "takes over" from the OCXO's better short-term stability. -- 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.
