Several years ago I replaced the OCXOs in some Tektronix DC5010 counters with surplus Oscilloquartz 8663 DOCXOs. The darn things have freaky good aging characteristics. They have been on 24/7 (except for a few brief power-outages) for over 3 years. After a month I set their freq against a cesium oscillator. They still show 10 MHz out to 8 or 9 decimal places. I just got in an Oscilloquartz Star-4 ATDC (automatic temperature / drift compensation) that uses the same DOCXO. They take 24 hours from a cold start before the ATDC learning kicks in (you can fake it out by power cycling during that interval and it thinks it was a brief outage and reports a 1 hour learning delay). After an unspecified time (at least several days) the device learns the compensation characteristics and the holdover performance status switches from POOR to IN-SPEC. I have not yet gotten it past the learning stage... Oh, and Lady Heather now speaks Star-4 management interface commands which are also used on a NEC GPSDO that shows up on Ebay... I have one of those on order. ------------------- > OSA8663: per year, 3.0E-8, in 10 years < 30.0E-8

Are Oscilloquartz's Star-4 commands described somewhere? I can't find them in the wild... On Sat, Nov 19, 2016 at 4:34 AM, Mark Sims <holrum@hotmail.com> wrote: > Several years ago I replaced the OCXOs in some Tektronix DC5010 counters with surplus Oscilloquartz 8663 DOCXOs. The darn things have freaky good aging characteristics. They have been on 24/7 (except for a few brief power-outages) for over 3 years. After a month I set their freq against a cesium oscillator. They still show 10 MHz out to 8 or 9 decimal places. > > I just got in an Oscilloquartz Star-4 ATDC (automatic temperature / drift compensation) that uses the same DOCXO. They take 24 hours from a cold start before the ATDC learning kicks in (you can fake it out by power cycling during that interval and it thinks it was a brief outage and reports a 1 hour learning delay). After an unspecified time (at least several days) the device learns the compensation characteristics and the holdover performance status switches from POOR to IN-SPEC. I have not yet gotten it past the learning stage... > > Oh, and Lady Heather now speaks Star-4 management interface commands which are also used on a NEC GPSDO that shows up on Ebay... I have one of those on order. > > ------------------- > >> OSA8663: per year, 3.0E-8, in 10 years < 30.0E-8 > _______________________________________________ > 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.