You can do the ADEV just fine using Circular T. Long-term 5071 does not dominate the TAI phase/frequency, but they do dominate for stability.
This is the difference between EAL and TAI, the 5071's go into EAL, but EAL is then frequency corrected with a handful of primary references (cesium fointains) into TAI. EAL just try to be as stable as possible, without careing too much about phase and frequency. Cheers, Magnus On 2021-03-26 11:00, Azelio Boriani wrote: > Maybe HP5071s will get their ADEV when optical clocks will officially rule... > > On Fri, Mar 26, 2021 at 9:40 AM Magnus Danielson <mag...@rubidium.se> wrote: >> Hi, >> >> On 2021-03-25 19:21, Poul-Henning Kamp wrote: >>> -------- >>> Attila Kinali writes: >>> >>>> Does someone of those who own a 5071 have long-term ADEV data? >>>> I'm looking for multi-year data. While there are plenty of ADEV >>>> plots online, most of them stop at 1Ms or even at 100ks. >>> As I understand it, cesium beams are considered "primary" standards >>> because once the ADEV hits the floor, it stays down there ? >> "primary" standard means different things in different context. >> >> In telecom, it means it adheres to ITU-T G.811 specifications, which >> effectively puts within 1E-11 in maximum frequency error, which is what >> analog cesiums can deliver. Most of the cesiums we attain as hobbyists >> was designed to meet this spec. The underlying specification driving it >> was to keep data-slip rate between two operators down to once in 70 >> days. It was reasonably achieveable with the technology at hand and for >> the total cost so I think it was fair. >> >> In metrology "primary standard" has a complete different meaning, and in >> practice all clocks we hobbyists gets to have would not fit, they would >> all be more or less good "secondary standards". >> >> The sales people for vendors will be happy to underblow the >> understanding of you being able to buy and have your own "primary >> standard". If it where, you would not be needing traceability to >> anything else, but you end up needing to have that anyway, and in >> reality the "primary" reference is actually one of the few that >> contributes to the international realization. I've seen a few of those, >> but not in my basement. >> >> The "primary reference" is not about ADEV hitting the floor, all devices >> do that (for a strict definition of what should be measured in ADEV). >> It's about the context one consider it "primary". >> >> It would be cool to say one has a "primary standard", and depending on >> context I have several working or none. Coolness aside, when talking to >> metrology folks and national metrology labs, I might have some clocks, >> but I do not call them "primary reference", because most of them does >> not have that either. >> >> So, I think we should be careful with the term, it's get thrown around >> too lightly. >> >> Cheers, >> Magnus >> _______________________________________________ >> time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an >> email to time-nuts-le...@lists.febo.com >> To unsubscribe, go to and follow the instructions there. > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an > email to time-nuts-le...@lists.febo.com > To unsubscribe, go to and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.