> The troll doesn't even know how to format a USENET post...As ironically stated by the John Doe <always.look@message.header> troll in message-id <sdhn7c$pkp$4@dont-email.me> who has posted yet another incorectly formatted USENET posting on Thu, 12 Aug 2021 16:41:02 -0000 (UTC) in message-id <sf3iuu$83o$2@dont-email.me>.
Precison sapphire oscillator
Started by ●August 11, 2021
Reply by ●August 12, 20212021-08-12
Reply by ●August 12, 20212021-08-12
> The troll doesn't even know how to format a USENET post...As ironically stated by the John Doe <always.look@message.header> troll in message-id <sdhn7c$pkp$4@dont-email.me> who has posted yet another incorectly formatted USENET posting on Thu, 12 Aug 2021 16:41:27 -0000 (UTC) in message-id <sf3ivn$83o$3@dont-email.me>.
Reply by ●August 12, 20212021-08-12
On 12/08/2021 03:49, Jeroen Belleman wrote:> On 2021-08-11 18:33, Spehro Pefhany wrote: >> On Wed, 11 Aug 2021 01:57:25 -0700 (PDT), Anthony William Sloman >> <bill.sloman@ieee.org> wrote: >> >>> A recent copy of the IEEE Spectrum included this article >>> >>> https://spectrum.ieee.org/for-precision-the-sapphire-clock-outshines-even-the-best-atomic-clocks >>> >>> >>> It isn't as stable as an atomic clock over an extended period but >>> it's short-term accuracy is much better.� Each clock period is much >>> closer to being perfectly equal to the last one. >>> >>> And it is an Australian development� ... >> >> Not surprising the pulsing from the cryocooler caused them some grief. >> It's too bad there's no practical way yet to get down to < 10K� using >> refrigeration without vibrations and such like. >> > > The IEEE Spectrum article is of particularly low quality. It seems > to actually make an effort to be as vague and useless as possible.IEEE Spectrum is frequently so dumbed-down that it is an embarrassment to their members (or at least it was until a few years ago when I stopped reading it and opted not to have it delivered to me even though I had already paid for it with my membership). If anyone were to see this publication and assume that it were written for IEEE members to read, and that this necessitated assuming such a low level of technical knowledge and ability, they might reasonably conclude that IEEE members were largely incompetent and unsuitable for any technical work. Personally I just assume that no engineers are involved in producing Spectrum.
Reply by ●August 12, 20212021-08-12
On Friday, August 13, 2021 at 9:55:01 AM UTC+10, Chris Jones wrote:> On 12/08/2021 03:49, Jeroen Belleman wrote: > > On 2021-08-11 18:33, Spehro Pefhany wrote: > >> On Wed, 11 Aug 2021 01:57:25 -0700 (PDT), Anthony William Sloman > >> <bill....@ieee.org> wrote: > >> > >>> A recent copy of the IEEE Spectrum included this article > >>> > >>> https://spectrum.ieee.org/for-precision-the-sapphire-clock-outshines-even-the-best-atomic-clocks > >>> > >>> > >>> It isn't as stable as an atomic clock over an extended period but > >>> it's short-term accuracy is much better. Each clock period is much > >>> closer to being perfectly equal to the last one. > >>> > >>> And it is an Australian development ... > >> > >> Not surprising the pulsing from the cryocooler caused them some grief. > >> It's too bad there's no practical way yet to get down to < 10K using > >> refrigeration without vibrations and such like. > >> > > > > The IEEE Spectrum article is of particularly low quality. It seems > > to actually make an effort to be as vague and useless as possible. > > IEEE Spectrum is frequently so dumbed-down that it is an embarrassment > to their members (or at least it was until a few years ago when I > stopped reading it and opted not to have it delivered to me even though > I had already paid for it with my membership). If anyone were to see > this publication and assume that it were written for IEEE members to > read, and that this necessitated assuming such a low level of technical > knowledge and ability, they might reasonably conclude that IEEE members > were largely incompetent and unsuitable for any technical work. > Personally I just assume that no engineers are involved in producing > Spectrum.You can read short biographies of the reporters. The IEEE is a very broad church, and stuff that is going to be comprehensible to all the members does have to be dumbed down quite a long way, to New Scientist and Scientific American levels. -- Bill Sloman, Sydney
Reply by ●August 12, 20212021-08-12
On Fri, 13 Aug 2021 09:54:54 +1000, Chris Jones <lugnut808@spam.yahoo.com> wrote:>On 12/08/2021 03:49, Jeroen Belleman wrote: >> On 2021-08-11 18:33, Spehro Pefhany wrote: >>> On Wed, 11 Aug 2021 01:57:25 -0700 (PDT), Anthony William Sloman >>> <bill.sloman@ieee.org> wrote: >>> >>>> A recent copy of the IEEE Spectrum included this article >>>> >>>> https://spectrum.ieee.org/for-precision-the-sapphire-clock-outshines-even-the-best-atomic-clocks >>>> >>>> >>>> It isn't as stable as an atomic clock over an extended period but >>>> it's short-term accuracy is much better.� Each clock period is much >>>> closer to being perfectly equal to the last one. >>>> >>>> And it is an Australian development� ... >>> >>> Not surprising the pulsing from the cryocooler caused them some grief. >>> It's too bad there's no practical way yet to get down to < 10K� using >>> refrigeration without vibrations and such like. >>> >> >> The IEEE Spectrum article is of particularly low quality. It seems >> to actually make an effort to be as vague and useless as possible. > >IEEE Spectrum is frequently so dumbed-down that it is an embarrassment >to their members (or at least it was until a few years ago when I >stopped reading it and opted not to have it delivered to me even though >I had already paid for it with my membership). If anyone were to see >this publication and assume that it were written for IEEE members to >read, and that this necessitated assuming such a low level of technical >knowledge and ability, they might reasonably conclude that IEEE members >were largely incompetent and unsuitable for any technical work. >Personally I just assume that no engineers are involved in producing >Spectrum.IEEE Spectrum is not intended as a technical journal of record. Although they do get articles written by technical experts, the staff are standard magazine writers and editors. The IEEE is at base a publisher. Joe Gwinn (Life Member)
Reply by ●August 12, 20212021-08-12
On Friday, August 13, 2021 at 1:55:54 AM UTC+10, jla...@highlandsniptechnology.com wrote:> On Wed, 11 Aug 2021 12:33:43 -0400, Spehro Pefhany > <spef...@interlogDOTyou.knowwhat> wrote: > > >On Wed, 11 Aug 2021 01:57:25 -0700 (PDT), Anthony William Sloman > ><bill....@ieee.org> wrote: > > > >>A recent copy of the IEEE Spectrum included this article > >> > >>https://spectrum.ieee.org/for-precision-the-sapphire-clock-outshines-even-the-best-atomic-clocks > >> > >>It isn't as stable as an atomic clock over an extended period but it's short-term accuracy is much better. Each clock period is much closer to being perfectly equal to the last one. > >> > >>And it is an Australian development ... > > > >Not surprising the pulsing from the cryocooler caused them some grief. > >It's too bad there's no practical way yet to get down to < 10K using > >refrigeration without vibrations and such like.\> > The usual atomic clock disciplines a quartz crystal oscillator with a > very slow feedback loop. Short-term (as in seconds at least) jitter is > from the crystal oscillator. In a really good source, you're paying > for a double ovenized SC-cut crystal more than for the rubidium thing.Presumably the sapphire oscillator is aimed at replacing the double ovenised SC-cut quartz crystal. It seems to be good enough that you could live without the feedback from the atomic clock in most applications. -- Bill Sloman, Sydney
Reply by ●August 13, 20212021-08-13
On a sunny day (Thu, 12 Aug 2021 08:55:45 -0700) it happened jlarkin@highlandsniptechnology.com wrote in <orgahgd5e5lsc1i6b939q98vbd3klulaee@4ax.com>:>On Wed, 11 Aug 2021 12:33:43 -0400, Spehro Pefhany ><speffSNIP@interlogDOTyou.knowwhat> wrote: > >>On Wed, 11 Aug 2021 01:57:25 -0700 (PDT), Anthony William Sloman >><bill.sloman@ieee.org> wrote: >> >>>A recent copy of the IEEE Spectrum included this article >>> >>>https://spectrum.ieee.org/for-precision-the-sapphire-clock-outshines-even-the-best-atomic-clocks >>> >>>It isn't as stable as an atomic clock over an extended period but it's short-term accuracy is much better. Each clock period >>>is much closer to being perfectly equal to the last one. >>> >>>And it is an Australian development ... >> >>Not surprising the pulsing from the cryocooler caused them some grief. >>It's too bad there's no practical way yet to get down to < 10K using >>refrigeration without vibrations and such like. > >The usual atomic clock disciplines a quartz crystal oscillator with a >very slow feedback loop. Short-term (as in seconds at least) jitter is >from the crystal oscillator. In a really good source, you're paying >for a double ovenized SC-cut crystal more than for the rubidium thing.I still have the rub-it-in-dium 10MHz reference from ebay I bought years ago, works great, reference for my satellite stuff. Better than the GPS stuff as it is constant and takes only a few minutes to warm up. I did notice prices have gone up on ebay for these a lot.
