Just a follow-up on this. Yesterday I received a Thunderbolt from fluke.l,
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=290322053618 This worked straight away and has cured the 50 minute drift cycle. I'm getting a standard deviation of pulse interval of about 0.25uS, as measured against the soundcard sample clock. It ought to be a bit better than this, but the 10uS PPS width is a bit too short for a steady timing of centroid through a soundcard at 192k samples/sec, I need to stretch the pulse a factor of 10 or so. The Thunderbolt seems to take about 45 mins to settle down to a steady rate, which is fine. Meanwhile, Garmin wrote to say they will try to reproduce the 50 minute drift on the GPS16X. So that problem is fixed. Thanks for the advice and suggestions. -- Paul Nicholson http://abelian.org -- _______________________________________________ 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.