Re: [time-nuts] Survey plot as art.

[Jay Grizzard]

I realize that, in theory, the designs for these things are relatively 
straightforward. Unfortunately, the *vast* majority of my experience is 
in the digital world, so the best I could probably do on my own is 
Frankenstein some hopefully-appropriate circuits together and hope the 
result is usable.


...that's a bit too luck-based for my tastes, so I was hoping someone 
had already put something appropriate together that I could just lay out 
and build. I'm actually a bit surprised that (apparently)  nobody on 
this list has done so, given how many GPSs we all must collectively own...


(...anybody want to? I'll fund the PCB & components for you to test your 
design...)


-j


The standard design is pretty simple:

1) DC bias coupler on the input
2) Protection on the input
3) Saw filter on the input (say -3 db)
4) Fairly normal (Mini Circuits) low noise amp with appropriate gain (say 12 to 
18 db)
5) two way splitter for the two banks of outputs (-3db)
6) two way splitter to each output (-3db)
(obviously a 4 output device)
7) 3 db  (to 9 db) pads on each output
8) DC blocks on all but one output.
9) DC bias coupler on the one “magic” output.

Some designs put a second filter after the amp. Some designs use ceramic 
filters rather than SAW’s.
Some designs go up to quite a few (like a dozen) outputs. Some have external 
power rather than
the bias pickoff / pass thru.



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Re: [time-nuts] hm H Maser

[Bruce Griffiths]

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 
 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) <
drkir...@kirkbymicrowave.co.uk> wrote:

> 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, 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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Re: [time-nuts] hm H Maser

[Ole Petter Ronningen]

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...@kirkbymicrowave.co.uk> wrote:

> 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, 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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Re: [time-nuts] hm H Maser

[Bruce Griffiths]

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 could also be 
useful.Note that with an integrating sphere (or any other random scattering 
process eg scattering from colloidal particles undergoing Brownian motion) 
laser polarisation isn't preserved which may be convenient.One potential issue 
with an  integrating sphere is the longevity of the diffusing coating 
(typically Barium sulphate with an organic binder). Roughening (fine grind  
followed by HF etch for stress relief) the outer surface of the cell is also 
advisable to eliminate light pipe effects in the cell wall.
Bruce 

On Wednesday, 11 January 2017 3:54 PM, Bruce Griffiths 
 wrote:
 

 A goal with ADEV ~ 1E-13/Tau (for Tau <1000sec) may be feasible as its already 
been done as part of a PhD thesis.Using as large a cavity as possible is 
probably useful so that a large cell can be employed.What resonant mode is 
desirable in the cavity?Do we need to avoid field reversal as in the hydrogen 
maser?
Bruce  

On Wednesday, 11 January 2017 3:43 PM, Bob Camp  wrote:
 

 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  
> 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  wrote:
> 
> 
> Hi
> 


   

   
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Re: [time-nuts] hm H Maser

[Bob Camp]

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  
> 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  wrote:
> 
> 
> Hi
> 

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Re: [time-nuts] hm H Maser

[Bruce Griffiths]

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 
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  wrote:
> 
> 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
>> 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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Re: [time-nuts] hm H Maser

[Bob Camp]

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  wrote:
> 
> 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
>> 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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Re: [time-nuts] hm H Maser

[Gregory Maxwell]

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
> 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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Re: [time-nuts] hm H Maser

[Bob kb8tq]

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  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
> 
> 
> 
> 
> 

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Re: [time-nuts] hm H Maser

[Tom Van Baak]

> 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
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Re: [time-nuts] hm H Maser

[paul swed]

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  wrote:

> Hi
>
> > On Jan 10, 2017, at 5:26 PM, Bob Stewart  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) <
> drkir...@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  >
> > 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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> mailman/listinfo/time-nuts
> > and follow the instructions there.
> >
> >
> >
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Re: [time-nuts] hm H Maser

[Bob kb8tq]

Hi

> On Jan 10, 2017, at 5:26 PM, Bob Stewart  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 
> 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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> 
> 
> 
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Re: [time-nuts] σ vs s in ADEV

[Bob kb8tq]

Hi

> On Jan 10, 2017, at 1:22 PM, Magnus Danielson  
> wrote:
> 
> Hi Bob,
> 
> On 01/10/2017 12:20 AM, Bob kb8tq wrote:
>> Hi
>> 
>>> On Jan 9, 2017, at 5:09 PM, Jeremy Nichols  wrote:
>>> 
>>> In the late 1960s, Hewlett-Packard engineers worked up a program to have
>>> the 5360A "Computing Pig" (so-called from its weight, 55 pounds without
>>> plug-ins) compute a "fractional frequency standard deviation." It appears
>>> to be similar to the Allen Deviation; I've never figured out the difference
>>> and would appreciate hearing from someone with stronger math skills who can
>>> explain the two.
>> 
>> The 5360A did ADEV. It only started being called ADEV after a few years had 
>> passed.
>> The 5360A program and it’s various quirks became the topic of a number of 
>> post paper
>> questions in the early 1970’s. The main focus of most of the questions was 
>> on bandwidth
>> limiting ahead of the counter. That question really didn’t get a proper 
>> answer for several
>> more decades.
> 
> I've not found much on that topic as I've searched. Care to point to a few 
> papers?
> 
> I've been looking at it, and you get somewhat different formulas if you 
> consider the filter.

It never came up in a paper. It was a question asked from the audience every 
time the NIST
guys presented an ADEV paper. After a while it got very predictable in terms of 
who would 
stand up and ask what.

Bob

> 
> Cheers,
> Magnus
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Re: [time-nuts] hm H Maser

[Bob Stewart]

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) 

 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 
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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Re: [time-nuts] hm H Maser

[Dr. David Kirkby (Kirkby Microwave Ltd)]

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, 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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Re: [time-nuts] hm H Maser

[Javier Herrero]

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 :

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, 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. 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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Re: [time-nuts] σ vs s in ADEV

[Magnus Danielson]

Hi Bob,

On 01/10/2017 12:20 AM, Bob kb8tq wrote:

Hi


On Jan 9, 2017, at 5:09 PM, Jeremy Nichols  wrote:

In the late 1960s, Hewlett-Packard engineers worked up a program to have
the 5360A "Computing Pig" (so-called from its weight, 55 pounds without
plug-ins) compute a "fractional frequency standard deviation." It appears
to be similar to the Allen Deviation; I've never figured out the difference
and would appreciate hearing from someone with stronger math skills who can
explain the two.


The 5360A did ADEV. It only started being called ADEV after a few years had 
passed.
The 5360A program and it’s various quirks became the topic of a number of post 
paper
questions in the early 1970’s. The main focus of most of the questions was on 
bandwidth
limiting ahead of the counter. That question really didn’t get a proper answer 
for several
more decades.


I've not found much on that topic as I've searched. Care to point to a 
few papers?


I've been looking at it, and you get somewhat different formulas if you 
consider the filter.


Cheers,
Magnus
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Re: [time-nuts] hm H Maser

[William H. Fite]

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 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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-- 
If you gaze long into an abyss, your coffee will get cold.
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Re: [time-nuts] hm H Maser

[jimlux]

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 




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.


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Re: [time-nuts] hm H Maser

[Ole Petter Rønningen]

"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 :
> 
> 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, 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. 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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> 
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Re: [time-nuts] hm H Maser

[Ole Petter Rønningen]

... 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 
> :
> 
> 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  
>> wrote:
>> 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, 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. 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 

Re: [time-nuts] hm H Maser

[Ole Petter Ronningen]

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 
wrote:

> 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) <
> 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. 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
> and follow the instructions there.
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>
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Re: [time-nuts] hm H Maser

[ewkehren via time-nuts]

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, 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. 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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Re: [time-nuts] hm H Maser

[Bob Camp]

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:
> 
>>> 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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[time-nuts] 5ms glitch on WAN ntp server peerstats at around 01:00 UTC today

[Mike Cook]

Hi,
  I saw 5ms offset jumps on most of the internet ntp servers that I am using at 
about 01:00UTC today. The servers are as widespread as NIST  Boulder, NPL UK, 
Hungary, Scotland, Spain, France, Czechoslovakia . Most but not all pool 
provided servers were not affected . It was not my ISPs or my routers that were 
implicated as the same phenomenon was visible on both networks. No local 
servers showed the symptom.
The majority of the affected servers are still showing the shifted offset, 
at+8hrs , though for a few there was a recovery to pre incident offsets withing 
a few minutes.

Did anybody else see anything at this time? If so have they an idea of the 
origin. 

Probably some WAN router reconfiguration or failure introducing large 
asymmetric delays. 

Regards

"The power of accurate observation is commonly called cynicism by those who 
have not got it. »
George Bernard Shaw

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Re: [time-nuts] FE-5650A option 58 tuning word for 10 MHz output

[Clint Jay]

Oh that's interesting,  I've not seen the non DDS version of the 5680 yet.

The frequency division for output in the non option  58 ones I've had hands
on was definitely done in a CPLD chip,  the DDS was "for internal use only"
 as far as I could tell.

On 10 Jan 2017 09:07, "wb6bnq"  wrote:

> Hi Clint,
>
> Actually there are two versions of the 5680.  The older version is exactly
> like the 5650 option 58 composition.  The newer version has the DDS as part
> of the signal generation for the physics package.  And it appears that they
> may be using an FPGA programmed as a divider to provide the output
> frequency.
>
> BillWB6BNQ
>
>
> Clint Jay wrote:
>
> Yes,  in the 5650 there's only DDS on opt 58,  in the 5680 there is one in
>> the main loop too,  my bad for not being precise/muddled.
>>
>> On 10 Jan 2017 01:43, "wb6bnq"  wrote:
>>
>>
>>
>>> HI Bob & Clint,
>>>
>>> If you look at the second message of this thread, I attached the manual
>>> that applies to Option 58.  Look at PDF page # 16 and you will see that
>>> there is no DDS in the physics package.  The DDS is only used down stream
>>> in some variations of the product such as the Option 58 being discussed.
>>>
>>> BillWB6BNQ
>>>
>>> Bob kb8tq wrote:
>>>
>>> Hi
>>>
>>>
 In most Rb’s (including the FE 56xx’s) the DDS is mixed with a fixed
 microwave frequency signal. The DDS only has to make up “part” of the
 total
 offset. You get
 roughly a three orders of magnitude improvement because of this. Rick
 has
 gone
 into all the gory details of why it gets done this way in talking about
 the 5071. It
 is the same thing on an Rb.
 So, your basic math is correct about a normal DDS. In this case you are
 in the
 PPT rather than PPB range due to the multiplication.
 Bob






> On Jan 9, 2017, at 10:40 AM, Scott Stobbe 
> wrote:
>
> A 32-bit DDS synthesizing at 1/5 Fs, yields a tuning resolution of ~ 1
> ppb.
> So, I would imagine a slightly lower frequency is programmed into the
> DDS
> and the c-field is trimmed to yield a higher precision. If the new
> synthesized tone you wish to generate is an integer number of DDS codes
> you
> could start by assuming the c-field is trimmed to be on frequency, but
> if
> the new tone is a fractional number of 32-bit DDS codes you will have
> to
> manually trim if you want higher precision.
>
> On Mon, Jan 9, 2017 at 4:48 AM, wb6bnq  wrote:
>
>
>
>
>
 ___
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>>> ___
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>>> and follow the instructions there.
>>>
>>>
>>>
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>> and follow the instructions there.
>>
>>
>>
>
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Re: [time-nuts] FE-5650A option 58 tuning word for 10 MHz output

[wb6bnq]

Hi Clint,

Actually there are two versions of the 5680.  The older version is 
exactly like the 5650 option 58 composition.  The newer version has the 
DDS as part of the signal generation for the physics package.  And it 
appears that they may be using an FPGA programmed as a divider to 
provide the output frequency.


BillWB6BNQ


Clint Jay wrote:


Yes,  in the 5650 there's only DDS on opt 58,  in the 5680 there is one in
the main loop too,  my bad for not being precise/muddled.

On 10 Jan 2017 01:43, "wb6bnq"  wrote:

 


HI Bob & Clint,

If you look at the second message of this thread, I attached the manual
that applies to Option 58.  Look at PDF page # 16 and you will see that
there is no DDS in the physics package.  The DDS is only used down stream
in some variations of the product such as the Option 58 being discussed.

BillWB6BNQ

Bob kb8tq wrote:

Hi
   


In most Rb’s (including the FE 56xx’s) the DDS is mixed with a fixed
microwave frequency signal. The DDS only has to make up “part” of the total
offset. You get
roughly a three orders of magnitude improvement because of this. Rick has
gone
into all the gory details of why it gets done this way in talking about
the 5071. It
is the same thing on an Rb.
So, your basic math is correct about a normal DDS. In this case you are
in the
PPT rather than PPB range due to the multiplication.
Bob




 


On Jan 9, 2017, at 10:40 AM, Scott Stobbe 
wrote:

A 32-bit DDS synthesizing at 1/5 Fs, yields a tuning resolution of ~ 1
ppb.
So, I would imagine a slightly lower frequency is programmed into the DDS
and the c-field is trimmed to yield a higher precision. If the new
synthesized tone you wish to generate is an integer number of DDS codes
you
could start by assuming the c-field is trimmed to be on frequency, but if
the new tone is a fractional number of 32-bit DDS codes you will have to
manually trim if you want higher precision.

On Mon, Jan 9, 2017 at 4:48 AM, wb6bnq  wrote:



   


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Re: [time-nuts] FE-5650A option 58 tuning word for 10 MHz output

[Clint Jay]

Yes,  in the 5650 there's only DDS on opt 58,  in the 5680 there is one in
the main loop too,  my bad for not being precise/muddled.

On 10 Jan 2017 01:43, "wb6bnq"  wrote:

> HI Bob & Clint,
>
> If you look at the second message of this thread, I attached the manual
> that applies to Option 58.  Look at PDF page # 16 and you will see that
> there is no DDS in the physics package.  The DDS is only used down stream
> in some variations of the product such as the Option 58 being discussed.
>
> BillWB6BNQ
>
> Bob kb8tq wrote:
>
> Hi
>>
>> In most Rb’s (including the FE 56xx’s) the DDS is mixed with a fixed
>> microwave frequency signal. The DDS only has to make up “part” of the total
>> offset. You get
>> roughly a three orders of magnitude improvement because of this. Rick has
>> gone
>> into all the gory details of why it gets done this way in talking about
>> the 5071. It
>> is the same thing on an Rb.
>> So, your basic math is correct about a normal DDS. In this case you are
>> in the
>> PPT rather than PPB range due to the multiplication.
>> Bob
>>
>>
>>
>>
>>> On Jan 9, 2017, at 10:40 AM, Scott Stobbe 
>>> wrote:
>>>
>>> A 32-bit DDS synthesizing at 1/5 Fs, yields a tuning resolution of ~ 1
>>> ppb.
>>> So, I would imagine a slightly lower frequency is programmed into the DDS
>>> and the c-field is trimmed to yield a higher precision. If the new
>>> synthesized tone you wish to generate is an integer number of DDS codes
>>> you
>>> could start by assuming the c-field is trimmed to be on frequency, but if
>>> the new tone is a fractional number of 32-bit DDS codes you will have to
>>> manually trim if you want higher precision.
>>>
>>> On Mon, Jan 9, 2017 at 4:48 AM, wb6bnq  wrote:
>>>
>>>
>>>
>>
>> ___
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>>
>>
>>
>
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