Yes, but as with quartz it varies a lot. I have tested a few LPROs, but have never seen a frequency jump in them. Those with more to test might have seen some jumps, but mine have been well behaved whenever they were being logged anyway.
I don't remember seeing actual jumps in the FE5680A's either, although the 2 older style 1pps-only ones did often have retrace jumps (like 5-10ppt) even after a short power down. The most obvious jumps I have seem were on a Temex LPRO/LPFRS which also had a borderline low peak Rb voltage, whether that had anything to do with it or not. At first it sometimes jumped in steps of 5-20ppt, and tapping it or even touching the connector on the RF cable from it would also often cause a jump. It was at its worst when I first powered it up, but even after many weeks on, they were still there occasionally. I've also tried a couple of the 9.8304MHz Sa.22c things recently, and other than being very basic spec, one had some fast frequency jumps and the other none that I saw - although near the middle of a 7 week test run it decided to change by 3E-11 over 15 hours or so. That is actually very like what I've seen sometimes in quartz where many days of aging happen in a few hours - I have MTI260's particularly keen on this trick. I had originally been interested in investigating jumps, but since they were most obvious in the poorer oscillators my interest waned a bit. Doing a search on rubidium frequency jumps turns up a fair bit, although much is on the GPS Rb's which unfortunately will not be cheap surplus any time soon - unless someone really messes up! Angus. From: "Hal Murray" To: "Discussion of precise time and frequency measurement" Sent: November 3, 2013 9:28 PM Subject: Re: [time-nuts] The 5MHz Sweet Spot Do low cost recycled Rubidiums have any quirks equivalent to frequency jumps in crystals? -- These are my opinions. I hate spam. _______________________________________________ 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. _______________________________________________ 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.
