Thinking outside the box a super reference
Yes. See attached.
On Thu, 3 Nov 2016 22:27:36 -0400, Chris Arnold via time-nuts wrote:
Will Lady Heather show the leap second using a thunderbolt?
chris
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Bill Beam
NL7F
Thanks
Sent from AOL Mobile Mail
-----Original Message-----
From: Bill Beam wbeam@gci.net
To: Discussion of precise time and frequency measurement time-nuts@febo.com; n3izn n3izn@aol.com; time-nuts time-nuts@febo.com
Sent: Thu, Nov 3, 2016 08:46 PM
Subject: Re: [time-nuts] Lady Heather and LeapSecond
Yes. See attached.
On Thu, 3 Nov 2016 22:27:36 -0400, Chris Arnold via time-nuts wrote:
Will Lady Heather show the leap second using a thunderbolt?
chris
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On Thu, 3 Nov 2016 23:52:00 +0000 (UTC)
Bruce Griffiths bruce.griffiths@xtra.co.nz wrote:
Attached graph indicates ADEV achieved with a 25mm double resonance Rb vapour cell
Performance appears somewhat better than HP5065A (even Corby's souped up version).
The thesis (by Thejesh N. Bandi) on this double resonance Rubidium vapour cell in a Magnetron style cavity was completed at the University of Neuchatel.
The dissertation in question is:
"Double-Resonance Studies on Compact, High-performance Rubidium Cell
Frequency Standards, bay Thejesh Bandi, 2013
https://doc.rero.ch/record/32317/files/00002318.pdf
Attila Kinali
--
It is upon moral qualities that a society is ultimately founded. All
the prosperity and technological sophistication in the world is of no
use without that foundation.
-- Miss Matheson, The Diamond Age, Neil Stephenson
You will also share the same challenges as Touchstone semi did, no one
wanted to stick their neck out to design in a little startup.
On Thu, Nov 3, 2016 at 7:49 PM, Bob Camp kb8tq@n1k.org wrote:
Hi
Not many people have had exposure to Rb’s or Cs standards actually being
built. That leaves a major gap in who you can call when you run into a
problem.
Until you have tried to build one it’s not at all clear just how much
“missing information” there
is in all those papers. It’s very much like the semiconductor business.
Lots of
information is published. There are indeed lots of gaps. At some point you
must
build tooling and get it all working.
Again, we are talking about a device that is at least as good as a 5065
and not
something that just barely works. If you could build something better
than a 5065
for a thousand or two dollars, it would be on the market today.
Bob
On Nov 3, 2016, at 6:34 PM, Attila Kinali attila@kinali.ch wrote:
On Thu, 3 Nov 2016 16:54:24 -0400
Bob Camp kb8tq@n1k.org wrote:
If you look at a modern CPU as “just a handful of sand and some stuff”,
it seems
pretty easy to build one in the kitchen after an hour or two of setup.
When you dig
into the nasty details the line costs rapidly spiral off into the
stratosphere. Atomic
standards are not quite as complex, but there still is more than just a
little custom
equipment involved. $1M sounds a bit on the low side of what it might
take.
Not necessarily. There is a large corpus of knowledge available on
how to build vapor cells standards and what is a good idea and what
isn't. Most of it is documented in papers of the PTTI, EFTF and IFCS.
The former two are freely available (for PTTI until 2010, but that
should be good enough). Getting access to those papers behind a
paywall, you only need to know someone with access to a university.
(not for PTTI post 2010 though, ION has quite anal access rules)
Additionally, the people in the time and frequeny community are very
open to discussion and exchange of knowledge. You can almost always
just walk up to someone and ask questions with a high chance of getting
not only answers but help in how to proceede.
Tapping into this knowhow would avoid the need to try out the whole
solution space and concentrate on the few parts that are unkown or
not well enough understood and optimize those. And by doing so safe
a lot of money.
Attila Kinali
--
Malek's Law:
Any simple idea will be worded in the most complicated way.
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Hi
You are indeed effectively either doing a startup or contracting with somebody
already in the business. In a lot of ways, contracting this out might be the easier
approach. The trick there will be having enough business to make it attractive
to them.
Bob
On Nov 4, 2016, at 11:21 AM, Scott Stobbe scott.j.stobbe@gmail.com wrote:
You will also share the same challenges as Touchstone semi did, no one
wanted to stick their neck out to design in a little startup.
On Thu, Nov 3, 2016 at 7:49 PM, Bob Camp kb8tq@n1k.org wrote:
Hi
Not many people have had exposure to Rb’s or Cs standards actually being
built. That leaves a major gap in who you can call when you run into a
problem.
Until you have tried to build one it’s not at all clear just how much
“missing information” there
is in all those papers. It’s very much like the semiconductor business.
Lots of
information is published. There are indeed lots of gaps. At some point you
must
build tooling and get it all working.
Again, we are talking about a device that is at least as good as a 5065
and not
something that just barely works. If you could build something better
than a 5065
for a thousand or two dollars, it would be on the market today.
Bob
On Nov 3, 2016, at 6:34 PM, Attila Kinali attila@kinali.ch wrote:
On Thu, 3 Nov 2016 16:54:24 -0400
Bob Camp kb8tq@n1k.org wrote:
If you look at a modern CPU as “just a handful of sand and some stuff”,
it seems
pretty easy to build one in the kitchen after an hour or two of setup.
When you dig
into the nasty details the line costs rapidly spiral off into the
stratosphere. Atomic
standards are not quite as complex, but there still is more than just a
little custom
equipment involved. $1M sounds a bit on the low side of what it might
take.
Not necessarily. There is a large corpus of knowledge available on
how to build vapor cells standards and what is a good idea and what
isn't. Most of it is documented in papers of the PTTI, EFTF and IFCS.
The former two are freely available (for PTTI until 2010, but that
should be good enough). Getting access to those papers behind a
paywall, you only need to know someone with access to a university.
(not for PTTI post 2010 though, ION has quite anal access rules)
Additionally, the people in the time and frequeny community are very
open to discussion and exchange of knowledge. You can almost always
just walk up to someone and ask questions with a high chance of getting
not only answers but help in how to proceede.
Tapping into this knowhow would avoid the need to try out the whole
solution space and concentrate on the few parts that are unkown or
not well enough understood and optimize those. And by doing so safe
a lot of money.
Attila Kinali
--
Malek's Law:
Any simple idea will be worded in the most complicated way.
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In message 2af27ebe-9200-c348-c89b-b98f9c973974@karlquist.com, "Richard (Rick) Karlquist" w
rites:
Also, one of the Rb isotopes is slightly radioactive.
35 years ago, the guy in the next cubicle got away with
storing it under his desk. He also happily smoked
cigarettes all day at his desk. Another ERA.
Rb87 has a halflife north of the age of the planet as far
as I recall, and the result is a beta which goes nowhere
far and Sr87 which is stable.
He got a lot more ionizing radiation from his cigaretess than he
ever got from the Rb87.
Just for the heck of it, I'd go laser instead of the old UHF lamp.
With respect to precision machining, that space has changed a lot
over the last five years, with precision CNC machines, factory
or home-built, dropping dramatically in price.
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
On Fri, Nov 4, 2016, at 02:27 PM, Poul-Henning Kamp wrote:
In message 2af27ebe-9200-c348-c89b-b98f9c973974@karlquist.com, "Richard
(Rick) Karlquist" w
rites:
Also, one of the Rb isotopes is slightly radioactive.
35 years ago, the guy in the next cubicle got away with
storing it under his desk. He also happily smoked
cigarettes all day at his desk. Another ERA.
Rb87 has a halflife north of the age of the planet as far
as I recall, and the result is a beta which goes nowhere
far and Sr87 which is stable.
87-Rb has a half life of something like 4.9e10 years — you'll be waiting
a while for that strontium. /gp
On Friday, November 04, 2016 09:27:59 PM Poul-Henning Kamp wrote:
"Richard
(Rick) Karlquist" w
rites:
Also, one of the Rb isotopes is slightly radioactive.
35 years ago, the guy in the next cubicle got away with
storing it under his desk. He also happily smoked
cigarettes all day at his desk. Another ERA.
Rb87 has a halflife north of the age of the planet as far
as I recall, and the result is a beta which goes nowhere
far and Sr87 which is stable.
He got a lot more ionizing radiation from his cigaretess than he
ever got from the Rb87.
Just for the heck of it, I'd go laser instead of the old UHF lamp.
With respect to precision machining, that space has changed a lot
over the last five years, with precision CNC machines, factory
or home-built, dropping dramatically in price.
Yes, the laser technique is doable even if one has to build an ECDL.
What would be nice would be a scheme that allows the same Rb filled bulb
to be used to both lock the laser to the right wavelength and to detect
that the microwave signal is also locked to the Rb microwave transition.
Bruce
Hi,
On 11/04/2016 10:27 PM, Poul-Henning Kamp wrote:
In message 2af27ebe-9200-c348-c89b-b98f9c973974@karlquist.com, "Richard (Rick) Karlquist" w
rites:
Also, one of the Rb isotopes is slightly radioactive.
35 years ago, the guy in the next cubicle got away with
storing it under his desk. He also happily smoked
cigarettes all day at his desk. Another ERA.
Rb87 has a halflife north of the age of the planet as far
as I recall, and the result is a beta which goes nowhere
far and Sr87 which is stable.
With a half-life of 49.2 Gigayears compared to universe life around 13.8
Gigayears and the beta-decay within both glas and metal enclosure, I'm
not overly concerned. For all practical purposes it is essentially stable.
He got a lot more ionizing radiation from his cigaretess than he
ever got from the Rb87.
Just for the heck of it, I'd go laser instead of the old UHF lamp.
The 780 nm laserdiodes isn't all that hard to get, in fact I've got some
lying around. Depolarizing needed with a quarter-wave needed not to get
a Stark-pull.
With respect to precision machining, that space has changed a lot
over the last five years, with precision CNC machines, factory
or home-built, dropping dramatically in price.
You need to tune it regardless.
Cheers,
Magnus
Hej Magnus
A quarter waveplate doesn't depolarise, it can however convert a linearly polarised beam to a circularly polarised one.If you really need to depolarise a laser beam, scattering from a colloidal suspension of Titanium dioxide is very effective.There are no macroscopic moving parts.Brownian motion of the colloidal partticels suffices.
Bruce
On Saturday, 5 November 2016 11:28 AM, Magnus Danielson <magnus@rubidium.dyndns.org> wrote:
Hi,
On 11/04/2016 10:27 PM, Poul-Henning Kamp wrote:
In message 2af27ebe-9200-c348-c89b-b98f9c973974@karlquist.com, "Richard (Rick) Karlquist" w
rites:
Also, one of the Rb isotopes is slightly radioactive.
35 years ago, the guy in the next cubicle got away with
storing it under his desk. He also happily smoked
cigarettes all day at his desk. Another ERA.
Rb87 has a halflife north of the age of the planet as far
as I recall, and the result is a beta which goes nowhere
far and Sr87 which is stable.
With a half-life of 49.2 Gigayears compared to universe life around 13.8
Gigayears and the beta-decay within both glas and metal enclosure, I'm
not overly concerned. For all practical purposes it is essentially stable.
He got a lot more ionizing radiation from his cigaretess than he
ever got from the Rb87.
Just for the heck of it, I'd go laser instead of the old UHF lamp.
The 780 nm laserdiodes isn't all that hard to get, in fact I've got some
lying around. Depolarizing needed with a quarter-wave needed not to get
a Stark-pull.
With respect to precision machining, that space has changed a lot
over the last five years, with precision CNC machines, factory
or home-built, dropping dramatically in price.
You need to tune it regardless.
Cheers,
Magnus
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