An entire room kept near to absolute zero with a simple door access???Unlikely,
likely the writer is unfamiliar with science/engineering.
Bruce
On Saturday, 14 January 2017 11:39 AM, Gary Woods
wrote:
Hydrogen maser in radio astronomy to sync worldwide systems:
http://flip.it/rmbdRQ
Hydrogen maser in radio astronomy to sync worldwide systems:
http://flip.it/rmbdRQ
(Lifted from the Albany, NY astronomy group).
--
Gary Woods O- K2AHC Public keys at home.earthlink.net/~garygarlic, or get
0x1D64A93D via keyserver
fingerprint = E2 6F 50 93 7B C7 F3 CA 1F 8B 3C C0 B0 28 6
Hi
The obvious question would be: What does it cost to set up a line to make a
proper
set of spherical Rb cells? Doing this as a glassblowing project is a dead end.
You
need it properly tooled ….
Bob
> On Jan 11, 2017, at 7:05 PM, Bruce Griffiths
> wrote:
>
> Angus
> Read the paper I posted
Angus
Read the paper I posted on the current state of the art.
ADEV ~ 2E-13/SQRT(Tau) is feasible with large cells and using a laser instead
of rubidium lamp.In principle, one can use the same cell to lock the laser to
the rubidium absorption line and lock the microwave signal.Suitable laser
dio
Hi
> On Jan 11, 2017, at 6:07 PM, Angus wrote:
>
> On Tue, 10 Jan 2017 21:43:07 -0500, you wrote:
>
>>
>> This does get back to state of the art Rb and what that means. In my
>> suggested case thats measured in terms of ADEV for Tau = 1 to 1,000,000
>> seconds. If you wanted an Rb with (o
On Tue, 10 Jan 2017 21:43:07 -0500, you wrote:
>
>This does get back to state of the art Rb and what that means. In my
>suggested case thats measured in terms of ADEV for Tau = 1 to 1,000,000
>seconds. If you wanted an Rb with (only) state of the art phase noise at 1 MHz
>offset
thats a d
Hi
A spherical set of cells is going to be a massive pain to fabricate. I believe
you can hit < 5x10^-12 / sqrt(tau) with
a fairly normal cell design and cavity design. There are some very basic issues
with the photo detector’s S/N that
also tip things towards a coaxial approach.
Bob
> On Jan
Hi
A cryo pump will get you into reliability issues if run 24/7. It also is
doubtful
that you will be able to maintain the vacuum level over long periods.
Bob
> On Jan 11, 2017, at 12:09 AM, Bruce Griffiths
> wrote:
>
> One could always use a cryo pump.
> The following paper is a summary of
In message <619617e1-aa26-4eb7-b73e-042f22912...@n1k.org>, Bob Camp writes:
>I guess the question then would be:
>
>Is a H Maser that runs 6.6 x 10^-12 at 1 second worth the trouble?
I would say absolutely not.
All things considered, I think a trapped-ion type standard would
be both m
In message <0C641805E0824C499D3C15F67F0B880B@pc52>, "Tom Van Baak" writes:
>To keep a maser room within 1 C or 0.1 C takes much more power [...]
Forget the power: Look at the installation costs.
If you want to be able to go in and pat your maser, the air volume
and flow has to be big e
One could always use a cryo pump.
The following paper is a summary of the current state of the art for rubidium
vapour frequency
standards:http://www.euramet.org/Media/docs/Repository/A169/IND55/micalizio_02182015.pdf
Bruce
On Wednesday, 11 January 2017 5:15 PM, Ole Petter Ronningen
wrot
Add to this ion-pumps (in the case of EFOS type masers 2 every ~2 years),
plus substantial tooling (turbomolecular vacuum pump, anyone?) to service
the thing - unless you want the manufacturer to do so..
Ole
On Tue, Jan 10, 2017 at 11:12 PM, Dr. David Kirkby (Kirkby Microwave Ltd) <
drkir...@kirk
A spherical cavity resonator with a spherical Rubidium cell configured as an
integrating sphere (to enhance the SNR of the optical absorption signal) is a
potential option. Its also possible to use the same cell to lock a 795 nm laser
to the desired wavelength. Fiber coupling the laser light co
Hi
I suspect that there are (or will be) some other cheaper / easier ways to do
the same thing. The signal to noise requirements
in the RF chain are sensitive to a couple of things, but not to an absurd
level. You do need good close in noise. I would not even bother to
go for a “final” RF sect
A possible RF chain for a Rubidium standard using off the shelf parts plus a
couple of custom microwave filters:https://arxiv.org/pdf/1204.4215.pdf
Bruce
On Wednesday, 11 January 2017 2:10 PM, Bob Camp wrote:
Hi
The gotcha is that 5065’s never were a popular item in HP’s lineup. As a
Hi
The gotcha is that 5065’s never were a popular item in HP’s lineup. As a
result, they are fairly sparse in the surplus market. Those who need them
for this or that application gobble them up on a regular basis. Trying to do
up a couple hundred “improved” 5065’s just isn’t going to happen (at
On Wed, Jan 11, 2017 at 12:25 AM, Bob kb8tq wrote:
> I have a pile of stuff. You have a pile of stuff. Others each have their pile
> of stuff. Doing
> a design that works only with my pile is possible. Doing a design that works
> with my pile
[...]
> You have to do it with a fairly standardized
Hi
Masers pop up in good (as in new or almost so) condition in the $30 to $70K
range from time to time. You *do* need to be a bit lucky, but compared to a
decade
long development process … not very lucky. The biggest issue with Masers is
that there
isn’t much of a market. They simply are to exp
> Looking at the Microsemi MHM 2010 Active Hydogen Maser data sheet, the
> maser has a peak power of 150 W and an operating power of 75 W. Based on a
> power consumption of 75 W, that is 657 kW hr / year of energy. I pay around
> £0.20 (GBP) per kW hr for electricity, so that's £131 (GBP) annually
tandards have such OCXO’s in them and
> that’s what they do.
>
> Bob
>
> > Bob
> >
> > From: Dr. David Kirkby (Kirkby Microwave Ltd) <
> drkir...@kirkbymicrowave.co.uk>
> > To: Discussion of precise time and frequency measurement <
> time-nuts@febo
conds or so). Indeed
*some* Cs standards have such OCXO’s in them and that’s what they do.
Bob
> Bob
>
> From: Dr. David Kirkby (Kirkby Microwave Ltd)
>
> To: Discussion of precise time and frequency measurement
> Sent: Tuesday, January 10, 2017 4:12 PM
> Subject: Re:
on of precise time and frequency measurement
Sent: Tuesday, January 10, 2017 4:12 PM
Subject: Re: [time-nuts] hm H Maser
On 10 January 2017 at 15:35, Ole Petter Rønningen
wrote:
> ... having said that, I for one think I'm with Bob on this one. The thing
> about masers are that
On 10 January 2017 at 15:35, Ole Petter Rønningen
wrote:
> ... having said that, I for one think I'm with Bob on this one. The thing
> about masers are that they are big. At least active masers. And they
> require a substantial volume be kept at ultra high vacuum - which is not
> trivial, especia
Hello,
Two kind of clocks were developed and qualified, a Rb and the PHM, and
it seems that this is the cost for the development of both (since it
mentions two on-board clock technologies). And this includes the
development of breadboards (EBBs, really full-fledged prototypes with no
qualifie
On Tuesday, January 10, 2017, jimlux wrote:
>
> This fits in the bucket of a cross-disciplinary project, like building a
> fusor, or a pulsed TEA laser, a Bose-Einstein Condensate generator, or any
> of a variety of similar projects.
Or a Lazar gravity warp generator.
>
> You can almost
On 1/10/17 7:35 AM, Ole Petter Rønningen wrote:
... having said that, I for one think I'm with Bob on this one. The
thing about masers are that they are big. At least active masers. And
they require a substantial volume be kept at ultra high vacuum -
which is not trivial, especially not in a home
"The European Commission and the European Space Agency have approved the
Galileo GNSS programme. Two experimental satellites will be launched in late
2005 or early 2006. Atomic clocks are critical for satellite navigation. After
more than ten years of development and an overall budget of € 30M,
... having said that, I for one think I'm with Bob on this one. The thing about
masers are that they are big. At least active masers. And they require a
substantial volume be kept at ultra high vacuum - which is not trivial,
especially not in a homeshop. The cavity needs to be kept at a temperat
Not sure how relevant that particular example is. PHM on Galileo was new
science (at least the sapphire loaded cavity), and *very* different
reliability engineering.
AHM's are nothing new, the science hace been done, the construction is
known, down to exact drawings and circuit diagrams. There are
Do we know what the PHM development for Galileo cost?
Sent from Samsung tabletBob Camp wrote:Hi
> On Jan 10, 2017, at 2:45 AM, Dr. David Kirkby (Kirkby Microwave Ltd)
> wrote:
>
> Once 9 Jan 2017 12:59, "Bob Camp" wrote:
>>
>> Hi
>>
>> Ok here are some rough numbers:
>>
>>> On Jan 9, 2
Hi
> On Jan 10, 2017, at 2:45 AM, Dr. David Kirkby (Kirkby Microwave Ltd)
> wrote:
>
> Once 9 Jan 2017 12:59, "Bob Camp" wrote:
>>
>> Hi
>>
>> Ok here are some rough numbers:
>>
>>> On Jan 9, 2017, at 4:35 AM, Dr. David Kirkby (Kirkby Microwave Ltd) <
> drkir...@kirkbymicrowave.co.uk> wrote
Once 9 Jan 2017 12:59, "Bob Camp" wrote:
>
> Hi
>
> Ok here are some rough numbers:
>
> > On Jan 9, 2017, at 4:35 AM, Dr. David Kirkby (Kirkby Microwave Ltd) <
drkir...@kirkbymicrowave.co.uk> wrote:
> > It would be interesting to see your breakdown of the costs and man hours
> > for an H2 maser.
Hi
Ok here are some rough numbers:
> On Jan 9, 2017, at 4:35 AM, Dr. David Kirkby (Kirkby Microwave Ltd)
> wrote:
>
> On 8 Jan 2017 17:34, "Bob Camp" wrote:
>
>> You are talking about a project that will take many years and likely
>> more money than the price of a new home. If that is “fun
Hi
> On Jan 9, 2017, at 1:05 AM, Bruce Griffiths
> wrote:
>
> For a rubidium vpour standard a cavity is essential, one could always use a
> microwave horn to illuminate the cell in an anechoic chamber.
The cavity in an Rb is not the ultra high Q monster that you have in a Maser.
There is
n
From "time-nuts" time-nuts-boun...@febo.com
To "Discussion of precise time and frequency measurement" time-nuts@febo.com
Cc
Date Mon, 9 Jan 2017 09:35:32 +0000
Subject Re: [time-nuts] hm H Maser
On 8 Jan 2017 17:34, "Bob Camp" wrote:
> You are
On 8 Jan 2017 17:34, "Bob Camp" wrote:
> You are talking about a project that will take many years and likely
> more money than the price of a new home. If that is “fun money”, then
> fine. For most people that sort of commitment is a bit outside the range
> of do it for fun.
It would be interes
For a rubidium vpour standard a cavity is essential, one could always use a
microwave horn to illuminate the cell in an anechoic chamber.
Using an integrating sphere can enhance the contrast of the optical signal
significantly.
http://www.princeton.edu/physics/graduate-program/theses/theses-from
Bob
As long as one stays away from CPT and merely uses the laser as a replacement
for the traditional rubidium lamp plus filters it should be easy enough as one
doesnt need to modulate the laser at 3.4 GHz.I was thinking something along the
lines of the recent PhD thesis that gave all the detail
Hi
> On Jan 8, 2017, at 11:57 AM, William H. Fite wrote:
>
> Bob, I think you're missing the point here. This is not the quest for
> utimate standards of accuracy/precision/resolution, it Is not about
> economic viability, or even attainability, let alone being "worth the
> trouble.".
>
> It is
Bob, I think you're missing the point here. This is not the quest for
utimate standards of accuracy/precision/resolution, it Is not about
economic viability, or even attainability, let alone being "worth the
trouble.".
It is about a fun project. Fun even if it comes to nothing. Is that
difficult t
Hi
> On Jan 8, 2017, at 11:21 AM, Dr. David Kirkby (Kirkby Microwave Ltd)
> wrote:
>
> On 8 January 2017 at 15:22, Bob Camp wrote:
>
>> Hi
>>
>> I guess the question then would be:
>>
>> Is a H Maser that runs 6.6 x 10^-12 at 1 second worth the trouble?
>>
>> With 100 KHz / C temperature c
On 8 January 2017 at 15:22, Bob Camp wrote:
> Hi
>
> I guess the question then would be:
>
> Is a H Maser that runs 6.6 x 10^-12 at 1 second worth the trouble?
>
> With 100 KHz / C temperature coefficients running around, getting
> good stability in a real world setting at 1 day will be “interest
Hi
I guess the question then would be:
Is a H Maser that runs 6.6 x 10^-12 at 1 second worth the trouble?
With 100 KHz / C temperature coefficients running around, getting
good stability in a real world setting at 1 day will be “interesting”.
Just for reference: The MH-2010 data sheet show
You could try a cavity like the one in;http://tf.nist.gov/general/pdf/156.pdf
This avoids the requirement for a fused quartz storage bulb.
Bruce
On Sunday, 8 January 2017 11:33 PM, timeok wrote:
Hi,
the thought of being able to work on building a H Maser has always accompanied
me in r
Hi,
the thought of being able to work on building a H Maser has always accompanied
me in recent years.
I fully understand the many difficulties of this project and also the necessity
of a work team.
Maybe a Passive Maser would be easiest to implement, but I do not know in
detail the processes
o
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