Hi I guess the real question is what a "better" OCXO would have actually cost.
If the 60111 was a test ten, get ten sort of thing (I'm guessing it was) - was a better part simply a test 10 get 9 issue? The claim was made that short term stability testing could be done directly in the aging racks. It's not real clear what the actual cost of an extended test / sort would have been. Bob On Mar 11, 2010, at 10:43 PM, John Miles wrote: > Many if not most 5370-based measurements are based on differential timing > between the START and STOP channels, and wouldn't benefit from a better 10 > MHz reference. If a customer did need something better, they probably > already had a house standard to pipe in the back... and if not, HP would > have been able to sell them one. It made more sense to keep the cost down > by not including a high-end OCXO that would have gone unappreciated by most > users. > > The 5370's jitter+resolution floor doesn't allow it to reach 1E-11 at t=1s > in any event, so the -60111 wouldn't have been the limiting factor in the > short term. > > One valid question, though, is why they bothered to put the nicer > 10811-60109 OCXOs in the post-2120 series 5065A models, where its short-term > performance is hosed by tying it to the rubidium reference with a ~1 Hz > loop. Those 5065As would have been OK with a -60111, at least in the > pre-2632 serial #s with the original integrator board. I'd be curious to > know if they lowered the loop BW when they respun the integrator PCB. > > -- john, KE5FX > > >> -----Original Message----- >> From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com]on >> Behalf Of Bob Camp >> Sent: Thursday, March 11, 2010 7:11 PM >> To: Discussion of precise time and frequency measurement >> Subject: [time-nuts] 5370B OCXO >> >> >> Hi >> >> The OCXO in the 5370B is a 10811-60111. The only added spec on it >> is a 1x10^-11 ADEV spec at 1 second. By modern standards that's >> not a real tight spec. There are other 10811's with tighter specs >> on them at 1 second. My guess is that it was not a real tight >> spec for the 10811 to hit. >> >> The short term would appear to contribute to the total error on >> the counter. Why not put a better oscillator in it? >> >> Bob >> >> >> >> _______________________________________________ >> 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. > _______________________________________________ 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.