Reply by Jan Panteltje ●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.
Reply by Anthony William Sloman ●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 Joe Gwinn ●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.&#4294967295; Each clock period is much 
>>>> closer to being perfectly equal to the last one.
>>>>
>>>> And it is an Australian development&#4294967295; ...
>>>
>>> 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&#4294967295; 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 Anthony William Sloman ●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 Chris Jones ●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.&#4294967295; Each clock period is much 
>>> closer to being perfectly equal to the last one.
>>>
>>> And it is an Australian development&#4294967295; ...
>>
>> 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&#4294967295; 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 Edward Hernandez ●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 Edward Hernandez ●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 16:41:02 -0000
(UTC) in message-id <sf3iuu$83o$2@dont-email.me>.
Reply by John Doe ●August 12, 20212021-08-12
"the concepts "male" and "female" are essentially social constructions" (Bill Sloman)

Bozo the Clown...

-- 
Anthony William Sloman <bill.sloman@ieee.org> wrote:


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> Subject: Re: Precison sapphire oscillator
> From: Anthony William Sloman <bill.sloman@ieee.org>
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> Content-Type: text/plain; charset="UTF-8"
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> Xref: reader02.eternal-september.org sci.electronics.design:640145
> 
> On Thursday, August 12, 2021 at 5:36:01 PM UTC+10, Jan Panteltje wrote:
>> On a sunny day (Wed, 11 Aug 2021 19:49:18 +0200) it happened Jeroen Belle
> man 
>> <jer...@nospam.please> wrote in <sf12iu$1dnb$1...@gioia.aioe.org>:
>> >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. 
>> > 
>> >This one is *much* better: 
>> ><https://www.adelaide.edu.au/ipas/our-research/defence-security/cryogeni
> c-sapphire-oscillator-the-sapphire-clock#publications>
>>
>> ThE qUesTion noW bEcomEs at 10^-15 relative to what is it moving 
>> and when brought back to down under after being tested at NIST for verifi
> cation 
>> will it still give the right date ;-??? 
> 
> The travelling clock experiment showed that it wouldn't.
> 
> https://en.wikipedia.org/wiki/Hafele%E2%80%93Keating_experiment
> 
> That was in 1971, with cesium beam atomic clocks and going around the world eastward and westward produced a roughly 300nsec time difference.
> 
> The differences are predictable.
>  
>> I mean all is relative is it not? 
> 
> Of course it is.
>  
>> 1 second in 40 million years with earth flying around a sun that flies in
>  a galaxy that flies away from the Big Ben sorry Big Bang 
>> in an other universe where a second equals an hour of coffee zipping, so 
> confused. 
> 
> Not so much confused as wrong, but Jan gets lots of stuff wrong.
> 
>> And does cooling it that much cause glow ball worming?
> 
> It takes energy, and if it was produced by burning fossil carbon (as it mostly is at the moment) it will have produced a little bit more global warming.
> 
> The electricity companies are going over to producing their power from renewable sources as much as they can - they are cheaper - but it is a slow process, and they are going to have get more grid storage (pumped hydro and big batteries) than they have at the moment, but that's coming on too.
> 
> -- 
> Bill Sloman, Sydney
> 
>
Reply by John Doe ●August 12, 20212021-08-12
"the concepts "male" and "female" are essentially social constructions" (Bill Sloman)

Bozo the Clown...

-- 
Anthony William Sloman <bill.sloman@ieee.org> wrote:


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> Subject: Precison sapphire oscillator
> From: Anthony William Sloman <bill.sloman@ieee.org>
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> 
> 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  ...
> 
> -- 
> Bill Sloman, Sydney
> 
> 
> 
> 
>
Reply by ●August 12, 20212021-08-12
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.





-- 

Father Brown's figure remained quite dark and still; 
but in that instant he had lost his head. His head was
always most valuable when he had lost it.