Re: [time-nuts] hm H Maser
Do we know what the PHM development for Galileo cost?
Sent from Samsung tabletBob Camp kb8tq@n1k.org wrote:Hi
On Jan 10, 2017, at 2:45 AM, Dr. David Kirkby (Kirkby Microwave Ltd) drkirkby@kirkbymicrowave.co.uk wrote:
Once 9 Jan 2017 12:59, "Bob Camp" kb8tq@n1k.org wrote:
Hi
Ok here are some rough numbers:
On Jan 9, 2017, at 4:35 AM, Dr. David Kirkby (Kirkby Microwave Ltd) <
drkirkby@kirkbymicrowave.co.uk> wrote:
It would be interesting to see your breakdown of the costs and man hours
for an H2 maser. I suspect that others would find cheaper/faster
solutions.
$100M for the H2
$25M for the Rb
With all due respect, and I apprectiate you have a good knowledge of this
field, but that's not a breakdown of costs or man hours I wanted to see,
but a cost which appears to be plucked from the air.
Hardly plucked from the air. The last Rb design that I was involved with was
roughly 5X that expensive.
There's a BIG difference between a volunteer effort where
- Salaries are not paid
- Items of test equipment are likely to be borrowed or people provide
access to them for no charge etc, - Academics are likely to provide consultancy for free, in return for being
on papers published. - Software licenses could probably be obtained free, or enough people get
trials.
That’s where the 5:1 cost reduction comes from.
compared to a commercial company building a maser where
- Salaries are paid
- All equipment is purchased new
- Bench power supplies with 3.5 digit displays are sent out for calibration
each year.
* No outside body will do anything except at a commercial rate. - Flights are booked for meetings which could be done over the Internet.
- High end software licenses are huge.
$500M for the fountain.
But on what basis do you arrive at that figure?
The numbers that the people who have done it come up with when you talk to them.
To get sponsorship for anything remotely close to those numbers, you
need to have some massively good credentials.
Bob
Yes agreed at $500M. But someone like Tom, who does have massively good
credentials, could perhaps get $500,000, and perhaps that wisely spent
could get a fountain built. Without knowing how you arrive at $500M, it is
not possible for anyone to look at ways of shaving that cost.
This is not a cheap field to be doing things in ….
Bob
The Lovell Telescope at Jodrell Bank in the UK was built on a shoestring
budget. It was at the time the world's largest steerable radio telephone.
Half a century later only 2 larger ones have been built.
Maybe I am too nieve.
Dave.
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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 numbers from
1982 that can possibly be used as a startingpoint for estimating an amateur
project in https://library.nrao.edu/public/memos/vlba/main/VLBA_65.pdf
As a side note, I am also not convinced that sourcing the fused quartz
teflon coated bulbs would be a show stopper for a limited number (<5) of
masers, I for one have one on my shelf. It is quite possible that old bulbs
for previous designs exists with the current manufacturers that they might
be willing to part with.
They are also still manufactured, Vremya or one of the others might be
willing to sell them - although I have no idea about the cost.
As another side note, on a trip to Switzerland I was allowed a glimpse of a
couple of the PHM's for Galileo in person. Impressive.
Ole
On Tue, Jan 10, 2017 at 2:18 PM, ewkehren via time-nuts time-nuts@febo.com
wrote:
Do we know what the PHM development for Galileo cost?
Sent from Samsung tabletBob Camp kb8tq@n1k.org wrote:Hi
On Jan 10, 2017, at 2:45 AM, Dr. David Kirkby (Kirkby Microwave Ltd) <
drkirkby@kirkbymicrowave.co.uk> wrote:
Once 9 Jan 2017 12:59, "Bob Camp" kb8tq@n1k.org wrote:
Hi
Ok here are some rough numbers:
On Jan 9, 2017, at 4:35 AM, Dr. David Kirkby (Kirkby Microwave Ltd) <
drkirkby@kirkbymicrowave.co.uk> wrote:
It would be interesting to see your breakdown of the costs and man
hours
for an H2 maser. I suspect that others would find cheaper/faster
solutions.
$100M for the H2
$25M for the Rb
With all due respect, and I apprectiate you have a good knowledge of
this
field, but that's not a breakdown of costs or man hours I wanted to see,
but a cost which appears to be plucked from the air.
Hardly plucked from the air. The last Rb design that I was involved with
was
roughly 5X that expensive.
There's a BIG difference between a volunteer effort where
- Salaries are not paid
- Items of test equipment are likely to be borrowed or people provide
access to them for no charge etc, - Academics are likely to provide consultancy for free, in return for
being
on papers published.
- Software licenses could probably be obtained free, or enough people
get
trials.
That’s where the 5:1 cost reduction comes from.
compared to a commercial company building a maser where
- Salaries are paid
- All equipment is purchased new
- Bench power supplies with 3.5 digit displays are sent out for
calibration
each year.
- No outside body will do anything except at a commercial rate.
- Flights are booked for meetings which could be done over the Internet.
- High end software licenses are huge.
$500M for the fountain.
But on what basis do you arrive at that figure?
The numbers that the people who have done it come up with when you talk to
them.
To get sponsorship for anything remotely close to those numbers, you
need to have some massively good credentials.
Bob
Yes agreed at $500M. But someone like Tom, who does have massively good
credentials, could perhaps get $500,000, and perhaps that wisely spent
could get a fountain built. Without knowing how you arrive at $500M, it
is
not possible for anyone to look at ways of shaving that cost.
This is not a cheap field to be doing things in ….
Bob
The Lovell Telescope at Jodrell Bank in the UK was built on a shoestring
budget. It was at the time the world's largest steerable radio
telephone.
Half a century later only 2 larger ones have been built.
Maybe I am too nieve.
Dave.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/
mailman/listinfo/time-nuts
and follow the instructions there.
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To unsubscribe, go to https://www.febo.com/cgi-bin/
mailman/listinfo/time-nuts
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... 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 temperature stable to 0.001 degree C. With 4-5 magnetic shields. Add to this costly pumps to keep the vacuum this low even if you succeed at reaching that vacuum.. There's easily 1-2KUSD running cost per year just to keep the maser running.
Granted, I've never built a maser, but personally I think the problems that would need to solving (and lead to learning) would be much more on the vacuum-systems, shielding and temperature long before electronics becomes a major factor. And the chance of actually get a result comparable to a commercial maser (or even just better than what you could realistically pick up from ebay for a few K) are pretty slim. And LOT of time and cash would be burned before you are even close to getting some sort of oscillation.
A rubidium does look like a more realistic project..
Dont get me wrong - it would be beyond cool if someone built a homemade maser. The first ones were built by regular people in regular labs, so sure it can be done.
Well, my $0.02 has been spent..
Ole
Den 10. jan. 2017 kl. 15.15 skrev Ole Petter Ronningen opronningen@gmail.com:
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 numbers from 1982 that can possibly be used as a startingpoint for estimating an amateur project in https://library.nrao.edu/public/memos/vlba/main/VLBA_65.pdf
As a side note, I am also not convinced that sourcing the fused quartz teflon coated bulbs would be a show stopper for a limited number (<5) of masers, I for one have one on my shelf. It is quite possible that old bulbs for previous designs exists with the current manufacturers that they might be willing to part with.
They are also still manufactured, Vremya or one of the others might be willing to sell them - although I have no idea about the cost.
As another side note, on a trip to Switzerland I was allowed a glimpse of a couple of the PHM's for Galileo in person. Impressive.
Ole
On Tue, Jan 10, 2017 at 2:18 PM, ewkehren via time-nuts time-nuts@febo.com wrote:
Do we know what the PHM development for Galileo cost?
Sent from Samsung tabletBob Camp kb8tq@n1k.org wrote:Hi
On Jan 10, 2017, at 2:45 AM, Dr. David Kirkby (Kirkby Microwave Ltd) drkirkby@kirkbymicrowave.co.uk wrote:
Once 9 Jan 2017 12:59, "Bob Camp" kb8tq@n1k.org wrote:
Hi
Ok here are some rough numbers:
On Jan 9, 2017, at 4:35 AM, Dr. David Kirkby (Kirkby Microwave Ltd) <
drkirkby@kirkbymicrowave.co.uk> wrote:
It would be interesting to see your breakdown of the costs and man hours
for an H2 maser. I suspect that others would find cheaper/faster
solutions.
$100M for the H2
$25M for the Rb
With all due respect, and I apprectiate you have a good knowledge of this
field, but that's not a breakdown of costs or man hours I wanted to see,
but a cost which appears to be plucked from the air.
Hardly plucked from the air. The last Rb design that I was involved with was
roughly 5X that expensive.
There's a BIG difference between a volunteer effort where
- Salaries are not paid
- Items of test equipment are likely to be borrowed or people provide
access to them for no charge etc, - Academics are likely to provide consultancy for free, in return for being
on papers published. - Software licenses could probably be obtained free, or enough people get
trials.
That’s where the 5:1 cost reduction comes from.
compared to a commercial company building a maser where
- Salaries are paid
- All equipment is purchased new
- Bench power supplies with 3.5 digit displays are sent out for calibration
each year. - No outside body will do anything except at a commercial rate.
- Flights are booked for meetings which could be done over the Internet.
- High end software licenses are huge.
$500M for the fountain.
But on what basis do you arrive at that figure?
The numbers that the people who have done it come up with when you talk to them.
To get sponsorship for anything remotely close to those numbers, you
need to have some massively good credentials.
Bob
Yes agreed at $500M. But someone like Tom, who does have massively good
credentials, could perhaps get $500,000, and perhaps that wisely spent
could get a fountain built. Without knowing how you arrive at $500M, it is
not possible for anyone to look at ways of shaving that cost.
This is not a cheap field to be doing things in ….
Bob
The Lovell Telescope at Jodrell Bank in the UK was built on a shoestring
budget. It was at the time the world's largest steerable radio telephone.
Half a century later only 2 larger ones have been built.
Maybe I am too nieve.
Dave.
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"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, two onboard clock technologies have been qualified. The author considers their current status and performance."
https://www.gim-international.com/content/article/onboard-galileo-atomic-clocks
Ole
Den 10. jan. 2017 kl. 14.18 skrev ewkehren via time-nuts time-nuts@febo.com:
Do we know what the PHM development for Galileo cost?
Sent from Samsung tabletBob Camp kb8tq@n1k.org wrote:Hi
On Jan 10, 2017, at 2:45 AM, Dr. David Kirkby (Kirkby Microwave Ltd) drkirkby@kirkbymicrowave.co.uk wrote:
Once 9 Jan 2017 12:59, "Bob Camp" kb8tq@n1k.org wrote:
Hi
Ok here are some rough numbers:
On Jan 9, 2017, at 4:35 AM, Dr. David Kirkby (Kirkby Microwave Ltd) <
drkirkby@kirkbymicrowave.co.uk> wrote:
It would be interesting to see your breakdown of the costs and man hours
for an H2 maser. I suspect that others would find cheaper/faster
solutions.
$100M for the H2
$25M for the Rb
With all due respect, and I apprectiate you have a good knowledge of this
field, but that's not a breakdown of costs or man hours I wanted to see,
but a cost which appears to be plucked from the air.
Hardly plucked from the air. The last Rb design that I was involved with was
roughly 5X that expensive.
There's a BIG difference between a volunteer effort where
- Salaries are not paid
- Items of test equipment are likely to be borrowed or people provide
access to them for no charge etc, - Academics are likely to provide consultancy for free, in return for being
on papers published. - Software licenses could probably be obtained free, or enough people get
trials.
That’s where the 5:1 cost reduction comes from.
compared to a commercial company building a maser where
- Salaries are paid
- All equipment is purchased new
- Bench power supplies with 3.5 digit displays are sent out for calibration
each year. - No outside body will do anything except at a commercial rate.
- Flights are booked for meetings which could be done over the Internet.
- High end software licenses are huge.
$500M for the fountain.
But on what basis do you arrive at that figure?
The numbers that the people who have done it come up with when you talk to them.
To get sponsorship for anything remotely close to those numbers, you
need to have some massively good credentials.
Bob
Yes agreed at $500M. But someone like Tom, who does have massively good
credentials, could perhaps get $500,000, and perhaps that wisely spent
could get a fountain built. Without knowing how you arrive at $500M, it is
not possible for anyone to look at ways of shaving that cost.
This is not a cheap field to be doing things in ….
Bob
The Lovell Telescope at Jodrell Bank in the UK was built on a shoestring
budget. It was at the time the world's largest steerable radio telephone.
Half a century later only 2 larger ones have been built.
Maybe I am too nieve.
Dave.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
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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 homeshop. The cavity needs
to be kept at a temperature stable to 0.001 degree C. With 4-5
magnetic shields. Add to this costly pumps to keep the vacuum this
low even if you succeed at reaching that vacuum.. There's easily
1-2KUSD running cost per year just to keep the maser running.
Lots of people spend $4/day on coffee.. that's $1200/yr..
I'd give up a cup of coffee to run a AHM <grin>
Granted, I've never built a maser, but personally I think the
problems that would need to solving (and lead to learning) would be
much more on the vacuum-systems, shielding and temperature long
before electronics becomes a major factor.
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.
You can almost always find a commercial solution that can do it
better/cheaper/more reliably - but the learning experience is valuable.
I have almost zero desire to fool with high vacuum systems again, but
the time I did it, I learned a lot.
And the chance of
actually get a result comparable to a commercial maser (or even just
better than what you could realistically pick up from ebay for a few
K) are pretty slim. And LOT of time and cash would be burned before
you are even close to getting some sort of oscillation.
A rubidium does look like a more realistic project..
Dont get me wrong - it would be beyond cool if someone built a
homemade maser. The first ones were built by regular people in
regular labs, so sure it can be done.
On Tuesday, January 10, 2017, jimlux jimlux@earthlink.net wrote:
<snip>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 always find a commercial solution that can do it
better/cheaper/more reliably - but the learning experience is valuable. I
have almost zero desire to fool with high vacuum systems again, but the
time I did it, I learned a lot.
And t
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ailman/listinfo/time-nuts
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--
If you gaze long into an abyss, your coffee will get cold.
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
qualified parts) and of qualification models (
http://www.spectratime.com/uploads/documents/ispace/PTTI_FCS_RAFS_PHM_2005.pdf
), designed and manufactured with flight-quality components since the
EQMs are submitted to all testing (thermal vacuum, vibration, life,
EMC...) to levels a lot more estringent than those applicable for a
commercial-use maser.
Taking into account that GIOVE-B (used as the in-flight test bed for the
PHM) cost was 72M€, surely excluding launch and deployment costs, I
suppose that excluding the PHM itself, it seem that 100M€ is the order
of magnitude for the development including in-flight testing platform.
Regards,
Javier
On 10/01/2017 17:22, Ole Petter Rønningen wrote:
"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, two onboard clock technologies have been qualified. The author considers their current status and performance."
https://www.gim-international.com/content/article/onboard-galileo-atomic-clocks
Ole
Den 10. jan. 2017 kl. 14.18 skrev ewkehren via time-nuts time-nuts@febo.com:
Do we know what the PHM development for Galileo cost?
Sent from Samsung tabletBob Camp kb8tq@n1k.org wrote:Hi
On Jan 10, 2017, at 2:45 AM, Dr. David Kirkby (Kirkby Microwave Ltd) drkirkby@kirkbymicrowave.co.uk wrote:
Once 9 Jan 2017 12:59, "Bob Camp" kb8tq@n1k.org wrote:
Hi
Ok here are some rough numbers:
On Jan 9, 2017, at 4:35 AM, Dr. David Kirkby (Kirkby Microwave Ltd) <
drkirkby@kirkbymicrowave.co.uk> wrote:
It would be interesting to see your breakdown of the costs and man hours
for an H2 maser. I suspect that others would find cheaper/faster
solutions.
$100M for the H2
$25M for the Rb
With all due respect, and I apprectiate you have a good knowledge of this
field, but that's not a breakdown of costs or man hours I wanted to see,
but a cost which appears to be plucked from the air.
Hardly plucked from the air. The last Rb design that I was involved with was
roughly 5X that expensive.
There's a BIG difference between a volunteer effort where
- Salaries are not paid
- Items of test equipment are likely to be borrowed or people provide
access to them for no charge etc, - Academics are likely to provide consultancy for free, in return for being
on papers published. - Software licenses could probably be obtained free, or enough people get
trials.
That’s where the 5:1 cost reduction comes from.
compared to a commercial company building a maser where
- Salaries are paid
- All equipment is purchased new
- Bench power supplies with 3.5 digit displays are sent out for calibration
each year. - No outside body will do anything except at a commercial rate.
- Flights are booked for meetings which could be done over the Internet.
- High end software licenses are huge.
$500M for the fountain.
But on what basis do you arrive at that figure?
The numbers that the people who have done it come up with when you talk to them.
To get sponsorship for anything remotely close to those numbers, you
need to have some massively good credentials.
Bob
Yes agreed at $500M. But someone like Tom, who does have massively good
credentials, could perhaps get $500,000, and perhaps that wisely spent
could get a fountain built. Without knowing how you arrive at $500M, it is
not possible for anyone to look at ways of shaving that cost.
This is not a cheap field to be doing things in ….
Bob
The Lovell Telescope at Jodrell Bank in the UK was built on a shoestring
budget. It was at the time the world's largest steerable radio telephone.
Half a century later only 2 larger ones have been built.
Maybe I am too nieve.
Dave.
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To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
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To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
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--
Javier Herrero
Chief Technology Officer EMAIL: jherrero@hvsistemas.com
HV Sistemas S.L. PHONE: +34 949 336 806
Teide 4, Núcleo 1 Of. 0.1 FAX: +34 949 336 792
28703 San Sebastián de los Reyes - Madrid - Spain WEB: http://www.hvsistemas.com
On 10 January 2017 at 15:35, Ole Petter Rønningen opronningen@gmail.com
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 homeshop. The cavity needs to be kept at a
temperature stable to 0.001 degree C. With 4-5 magnetic shields. Add to
this costly pumps to keep the vacuum this low even if you succeed at
reaching that vacuum.. There's easily 1-2KUSD running cost per year just to
keep the maser running.
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. I
believe electricity is cheaper in the USA than here in the UK, but
converting £131 (GBP) to USD, that's around $161/year in electricity. So
running costs don't seem to be an issue.
But I must admit, the thought of spending a lot of time/money to build
something I could have bought for a lot less with higher performance is not
that attractive, although of course there would be a satisfaction from
building it yourself.
Dave
This may be a dumb question, but how much of an H Maser's advantage over a Cs Standard, for us mere mortal time-nuts, is down to the output oscillator it uses, rather than the reference source (H MASER or Cs beam)?
Bob
From: Dr. David Kirkby (Kirkby Microwave Ltd) <drkirkby@kirkbymicrowave.co.uk>
To: Discussion of precise time and frequency measurement time-nuts@febo.com
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 opronningen@gmail.com
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 homeshop. The cavity needs to be kept at a
temperature stable to 0.001 degree C. With 4-5 magnetic shields. Add to
this costly pumps to keep the vacuum this low even if you succeed at
reaching that vacuum.. There's easily 1-2KUSD running cost per year just to
keep the maser running.
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. I
believe electricity is cheaper in the USA than here in the UK, but
converting £131 (GBP) to USD, that's around $161/year in electricity. So
running costs don't seem to be an issue.
But I must admit, the thought of spending a lot of time/money to build
something I could have bought for a lot less with higher performance is not
that attractive, although of course there would be a satisfaction from
building it yourself.
Dave
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and follow the instructions there.
Hi
On Jan 10, 2017, at 5:26 PM, Bob Stewart bob@evoria.net wrote:
This may be a dumb question, but how much of an H Maser's advantage over a Cs Standard, for us mere mortal time-nuts, is down to the output oscillator it uses, rather than the reference source (H MASER or Cs beam)?
Pretty much none. You can design one with a crummy OCXO, but the question becomes - why would you do that? Putting a $10,000 OCXO into a $150K device is not that big a deal. If you put the same OCXO into a Cs standard, it would run a bit better out to the cross over point (a few 100 seconds 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) <drkirkby@kirkbymicrowave.co.uk>
To: Discussion of precise time and frequency measurement time-nuts@febo.com
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 opronningen@gmail.com
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 homeshop. The cavity needs to be kept at a
temperature stable to 0.001 degree C. With 4-5 magnetic shields. Add to
this costly pumps to keep the vacuum this low even if you succeed at
reaching that vacuum.. There's easily 1-2KUSD running cost per year just to
keep the maser running.
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. I
believe electricity is cheaper in the USA than here in the UK, but
converting £131 (GBP) to USD, that's around $161/year in electricity. So
running costs don't seem to be an issue.
But I must admit, the thought of spending a lot of time/money to build
something I could have bought for a lot less with higher performance is not
that attractive, although of course there would be a satisfaction from
building it yourself.
Dave
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I have enjoyed reading the thread and learned a bit. But given some of the
other threads I have read on improving RBs and CS's don't they make more
sense for most Time Nuts. I mean the conversations in the $100K and above
and outside of being fun to read doesn't make sense at all.
If I had $100K I would buy a new CS or slightly worn and save the rest...
There is a very real aspect of the conversation thats very interesting. Say
you are building a maser thats as good as a C or maybe not quite. The fact
that it can be refilled does give the system a very very long life. What
opportunity does this give you in simplifying the design and cost? What is
the thing thats driving up the cost?
Hex pole magnets, the cavity....
Regards
Paul.
WB8TSL
On Tue, Jan 10, 2017 at 6:02 PM, Bob kb8tq kb8tq@n1k.org wrote:
Hi
On Jan 10, 2017, at 5:26 PM, Bob Stewart bob@evoria.net wrote:
This may be a dumb question, but how much of an H Maser's advantage over
a Cs Standard, for us mere mortal time-nuts, is down to the output
oscillator it uses, rather than the reference source (H MASER or Cs beam)?
Pretty much none. You can design one with a crummy OCXO, but the
question becomes - why would you do that? Putting a $10,000 OCXO into a
$150K device is not that big a deal. If you put the same OCXO into a Cs
standard, it would run a bit better out to the cross over point (a few 100
seconds 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: [time-nuts] hm H Maser
On 10 January 2017 at 15:35, Ole Petter Rønningen <opronningen@gmail.com
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 homeshop. The cavity needs to be kept at a
temperature stable to 0.001 degree C. With 4-5 magnetic shields. Add to
this costly pumps to keep the vacuum this low even if you succeed at
reaching that vacuum.. There's easily 1-2KUSD running cost per year
just to
keep the maser running.
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. I
believe electricity is cheaper in the USA than here in the UK, but
converting £131 (GBP) to USD, that's around $161/year in electricity. So
running costs don't seem to be an issue.
But I must admit, the thought of spending a lot of time/money to build
something I could have bought for a lot less with higher performance is
not
that attractive, although of course there would be a satisfaction from
building it yourself.
Dave
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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. I
believe electricity is cheaper in the USA than here in the UK, but
converting £131 (GBP) to USD, that's around $161/year in electricity. So
running costs don't seem to be an issue.
Dave,
The cost of the lab and the cost of A/C must also be factored in. To keep a maser room within 1 C or 0.1 C takes much more power than the maser itself. Add to that the power consumed by the UPS(s) and all the other support instrumentation required to tend to a maser and it adds up, in both power and money.
Ole's estimate of 1-2k/yr is much closer to the truth than your $161/yr.
/tvb
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 expensive for what they do. Neat devices
most certainly. I’d love to have several of them. Selling the house to buy several, is not
going to go over well with the rest of the family …..
One point about this that is a bit significant:
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
and your pile is unlikely. Doing one that works with all the piles is impossible. If I sit here and
decide that my pile is the only one that matters, I then conclude that others should put a few
(hundred) man-years into making it all work. That’s nonsense. The only rational project that
others will toss in a decade of time to is one where they each get a device as a result. You
can’t do that with my pile / your pile / all the piles. You have to do it with a fairly standardized
design. That means buying (at the very least) kits of parts. Like it or not, the parts kit for a
Rb will be cheaper than the parts kit for any of the other devices…..
Bob
On Jan 10, 2017, at 6:24 PM, paul swed paulswedb@gmail.com wrote:
I have enjoyed reading the thread and learned a bit. But given some of the
other threads I have read on improving RBs and CS's don't they make more
sense for most Time Nuts. I mean the conversations in the $100K and above
and outside of being fun to read doesn't make sense at all.
If I had $100K I would buy a new CS or slightly worn and save the rest...
There is a very real aspect of the conversation thats very interesting. Say
you are building a maser thats as good as a C or maybe not quite. The fact
that it can be refilled does give the system a very very long life. What
opportunity does this give you in simplifying the design and cost? What is
the thing thats driving up the cost?
Hex pole magnets, the cavity....
Regards
Paul.
WB8TSL
On Wed, Jan 11, 2017 at 12:25 AM, Bob kb8tq kb8tq@n1k.org 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
design. That means buying (at the very least) kits of parts. Like it or not, the parts kit for a
Rb will be cheaper than the parts kit for any of the other devices…..
I read the occasional posts by PHK on his efforts to upgrade the
electronics in his 5065a and Corby's SUPER physics package upgrade
with great interest. I have wondered if the end result may be that
incremental upgrades to someone elses classic design, adding on modern
synthesizers and digital control, etc. Might eventually result in a
'Ship of Theseus' oscillator, which in its final form is buildable
from relatively easily sourced parts (plus perhaps a rubidium cell
that could be group bought at non-absurd prices).
Presumably taking an already established design and improving it
incrementally has lower risk and costs than a new design. In
particular, it can start off with 5065a as "my pile" inputs, but by
the end it doesn't have them anymore... and not just lest risky but
also a more natural way to divide the effort up into less
professionally-sized chunks.
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 least
without driving the current price up by > 10X or 100X).
Since about the only thing you keep from the 5065 once you are done is the
physics package, that’s a big payout for very few usable parts. You then
modify (and possibly repair) the physics package. If we ever get into this, you
also replace a few parts in there to improve it’s performance. Now you have
even fewer “keeper” parts.
Simple approach:
Decide you want a state of the art Rb (what other goal would there be?)
Organize the team
Work out a first pass design
Find a source for large Rb cell sets.
Work with them to get the cells right
Design up a physics package in parallel with this effort
Get it all prototyped multiple times and debugged with lash up electronics
Test for about a year once you have the prototype debugged
Order up the tooling on the long lead stuff (cells and some machined parts)
Get the real electronics working in some form
Debug the electronics against the real cells and parts
Test for about a year once you think it’s working
Do the real layouts and packaging, including shielding and all the other nasty stuff
Fit up the first unit
Test for about a year to be sure you have caught all the issues
Redo what is needed
Start building the hundred or so units on order with the cash on hand from those orders.
Lots of fun !!
I’m sure somebody will chime in at this point and claim they can do that all
for about $100 a unit. If so feel free to try. It’s simply liars poker at that point
since nobody ever has to actually do it. Based on having done it and on having
seen others do it … it is not at all cheap to do. Rb is cheaper, but it’s still not free.
You might also question the “test for a year” stuff. If you want ADEV style data that has
any meaning, you need sample sizes that are in the 10 to 100X tau range. For a one
week tau, each run will be > 3 months. Testing takes time…..You also need to be
testing multiple units to get any confidence. That takes money.
Even more fun.
Bob
On Jan 10, 2017, at 7:40 PM, Gregory Maxwell gmaxwell@gmail.com wrote:
On Wed, Jan 11, 2017 at 12:25 AM, Bob kb8tq kb8tq@n1k.org 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
design. That means buying (at the very least) kits of parts. Like it or not, the parts kit for a
Rb will be cheaper than the parts kit for any of the other devices…..
I read the occasional posts by PHK on his efforts to upgrade the
electronics in his 5065a and Corby's SUPER physics package upgrade
with great interest. I have wondered if the end result may be that
incremental upgrades to someone elses classic design, adding on modern
synthesizers and digital control, etc. Might eventually result in a
'Ship of Theseus' oscillator, which in its final form is buildable
from relatively easily sourced parts (plus perhaps a rubidium cell
that could be group bought at non-absurd prices).
Presumably taking an already established design and improving it
incrementally has lower risk and costs than a new design. In
particular, it can start off with 5065a as "my pile" inputs, but by
the end it doesn't have them anymore... and not just lest risky but
also a more natural way to divide the effort up into less
professionally-sized chunks.
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To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
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 <kb8tq@n1k.org> wrote:
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 least
without driving the current price up by > 10X or 100X).
Since about the only thing you keep from the 5065 once you are done is the
physics package, that’s a big payout for very few usable parts. You then
modify (and possibly repair) the physics package. If we ever get into this, you
also replace a few parts in there to improve it’s performance. Now you have
even fewer “keeper” parts.
Simple approach:
Decide you want a state of the art Rb (what other goal would there be?)
Organize the team
Work out a first pass design
Find a source for large Rb cell sets.
Work with them to get the cells right
Design up a physics package in parallel with this effort
Get it all prototyped multiple times and debugged with lash up electronics
Test for about a year once you have the prototype debugged
Order up the tooling on the long lead stuff (cells and some machined parts)
Get the real electronics working in some form
Debug the electronics against the real cells and parts
Test for about a year once you think it’s working
Do the real layouts and packaging, including shielding and all the other nasty stuff
Fit up the first unit
Test for about a year to be sure you have caught all the issues
Redo what is needed
Start building the hundred or so units on order with the cash on hand from those orders.
Lots of fun !!
I’m sure somebody will chime in at this point and claim they can do that all
for about $100 a unit. If so feel free to try. It’s simply liars poker at that point
since nobody ever has to actually do it. Based on having done it and on having
seen others do it … it is not at all cheap to do. Rb is cheaper, but it’s still not free.
You might also question the “test for a year” stuff. If you want ADEV style data that has
any meaning, you need sample sizes that are in the 10 to 100X tau range. For a one
week tau, each run will be > 3 months. Testing takes time…..You also need to be
testing multiple units to get any confidence. That takes money.
Even more fun.
Bob
On Jan 10, 2017, at 7:40 PM, Gregory Maxwell gmaxwell@gmail.com wrote:
On Wed, Jan 11, 2017 at 12:25 AM, Bob kb8tq kb8tq@n1k.org 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
design. That means buying (at the very least) kits of parts. Like it or not, the parts kit for a
Rb will be cheaper than the parts kit for any of the other devices…..
I read the occasional posts by PHK on his efforts to upgrade the
electronics in his 5065a and Corby's SUPER physics package upgrade
with great interest. I have wondered if the end result may be that
incremental upgrades to someone elses classic design, adding on modern
synthesizers and digital control, etc. Might eventually result in a
'Ship of Theseus' oscillator, which in its final form is buildable
from relatively easily sourced parts (plus perhaps a rubidium cell
that could be group bought at non-absurd prices).
Presumably taking an already established design and improving it
incrementally has lower risk and costs than a new design. In
particular, it can start off with 5065a as "my pile" inputs, but by
the end it doesn't have them anymore... and not just lest risky but
also a more natural way to divide the effort up into less
professionally-sized chunks.
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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 section until the physics stuff had been worked out. Designing today vs designing in a couple
of years will always be the more expensive approach. For the lash up, I might well gut parts out of an existing
cheap Rb simply to get things going …. who knows. Maybe we would need a chain like the one in the paper to figure out
what is going on. In four years take a look at what is on the market and make some decisions about the “final” RF chain.
Even then you might revisit it several years after that due to cost or performance issues….
This does get back to “state of the art Rb” and what that means. In my suggested case that’s 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 … that’s a different thing. State of the art for
power consumption and size is also not what I’m suggesting in this case. Why the choice of spec? … this is TimeNuts.
For some guidance on what state of the art in Rb’s is in this area, check out the many papers on the GPS Rb’s published in in the ION conference proceedings.
Can a bunch of hackers do quite that well? … likely not. They have been fiddling with that design for many decades. They also have a pretty healthy budget to
produce each one they build. We certainly can try to get as close as we can. Testing ours in orbit might put a strain on the budget though :)
Bob
On Jan 10, 2017, at 9:15 PM, Bruce Griffiths bruce.griffiths@xtra.co.nz wrote:
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 <kb8tq@n1k.org> wrote:
Hi
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) <
drkirkby@kirkbymicrowave.co.uk> wrote:
On 10 January 2017 at 15:35, Ole Petter Rønningen opronningen@gmail.com
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 homeshop. The cavity needs to be kept at a
temperature stable to 0.001 degree C. With 4-5 magnetic shields. Add to
this costly pumps to keep the vacuum this low even if you succeed at
reaching that vacuum.. There's easily 1-2KUSD running cost per year just
to
keep the maser running.
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. I
believe electricity is cheaper in the USA than here in the UK, but
converting £131 (GBP) to USD, that's around $161/year in electricity. So
running costs don't seem to be an issue.
But I must admit, the thought of spending a lot of time/money to build
something I could have bought for a lot less with higher performance is not
that attractive, although of course there would be a satisfaction from
building it yourself.
Dave
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and follow the instructions there.
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 <opronningen@gmail.com> wrote:
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) <
drkirkby@kirkbymicrowave.co.uk> wrote:
On 10 January 2017 at 15:35, Ole Petter Rønningen <opronningen@gmail..com>
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 homeshop. The cavity needs to be kept at a
temperature stable to 0.001 degree C. With 4-5 magnetic shields. Add to
this costly pumps to keep the vacuum this low even if you succeed at
reaching that vacuum.. There's easily 1-2KUSD running cost per year just
to
keep the maser running.
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. I
believe electricity is cheaper in the USA than here in the UK, but
converting £131 (GBP) to USD, that's around $161/year in electricity.. So
running costs don't seem to be an issue.
But I must admit, the thought of spending a lot of time/money to build
something I could have bought for a lot less with higher performance is not
that attractive, although of course there would be a satisfaction from
building it yourself.
Dave
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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 enough that the 100W heating and increased
humidity you bring does not throw your environment system off balance.
For +/- .5K, you can do that in an existing room.
You need something like 20-40 square meters with about 20cm thermal
insulation in all directions, and a two level 10:1 heat/cool
ventilation kit, capable of handling your local climatic excursions.
For +/- 50mK, building-in-building design is required.
You probably need at least 100 square meters in the interior building
if you want to be able to go in there and stay in tolerance and you
can only stand downwind from the maser at all times.
You will need to think a lot about power fluctuations. Lightning
must be permanent ON and you may need voltage regulation. Sunlight
through windows are VerBoten.
You will need a three level 100:10:1 heat/cool A/C setup, and the
":1" level is too big for TECs. You'll need very competent mixing
(I hope your wife likes the look of the Pompidou center) and even
more competent measurement and regulation.
Building-in-building-in-existing-barn is probably the cheapest you
can do this, and the maser is certainly going to be cheaper.
--
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.