AK
Attila Kinali
Sun, Mar 16, 2025 9:06 PM
A wonderful good Sunday everyone,
Thanks for all the intersting answers.
I'm going to pick a few of the points made and add some comments.
I'll do this in one mail, as not to clutter the mailinglist too much.
On Wed, 12 Mar 2025 16:21:33 -0400
Bob Camp via time-nuts time-nuts@lists.febo.com wrote:
The main “issue” in terms of a lack of papers seems to be that the tie between cause and effect still
is in the “maybe” category. Over the years, the magnitude of the jumps has dropped. Folks are fixing
something. Most likely they are fixing a number of things that each can create a jump. Tying each change
to this or that maybe 5 or 10% improvement …. good luck.
So, we still have this issue, but as people run out of ideas how to fix it,
they just chose to live with it as well as they can?
On Wed, 12 Mar 2025 14:45:57 -0700
Richard Karlquist via time-nuts time-nuts@lists.febo.com wrote:
The method
used to "improve" aging consisted of burning in crystals on an "ager"
system and shipping oscillators (containing crystals) when they achieved
the aging spec they needed.
How did this ager look like? Was it just the bare crystal package in a
bread-board like oscillator, attached to some frequency counter to measure
it's long term behavior?
I remember when I first got involved in
crystal oscillators around 1973, before I worked for HP, I was
introduced to crystals from "Colorado Crystal" that were packaged in
glass packages. Their frequency aging was mostly or completely in the
positive direction (higher frequency as time passed). Conventional
metal packages mostly were negative aging. This was explained to be me
by the fact that glass didn't outgass anything that would land on the
resonator and lower its frequency.
I have looked at data from ultra high vacuum (UHV) systems and I am pretty sure
that this theory is not fully correct. While it is true that metal surfaces
are full of water and hydrocarbons and that they require proper cleaning
and out-gasing procedure prior to use in UHV systems, glass is even more
porous and contains quite a bit of content that can outgas (technical
glasses used in UHV have about the same outgasing performance as metals).
I think that the biggest difference is, that glass is more "sticky" for the
larger molecules (i.e. hydrocarbons) than quartz, thus the equilibrium
point of these molecules sticking to surfaces shifts towards them sticking more
to glass than the crystal, thus making the crystal surface lighter.
I have also been told (by either by John Vig or Gregory Weaver), that glass
packages in space perform much better than metal packages in space, while
on earth the difference is not significant (probably after applying all types
of cleaning before sealing). This suggests, that glass is porous enough that
smaller contaminants (single atomic and di-atomic gasses, water,..) can get
through the glass and outgas into space. But I have not seen any data that
would support this, nor have I been told about any real measuruement that
would support this hypothesis.
Also, Jack was busy giving private training classes to numerous crystal
fabricators so that we could establish alternative crystal oscillator
sources.
I have been told a few times about this quest of Jack Kusters', but I could
not find any documentation thereof. Do you know whether some form of written
document from these training sessions are left and maybe even where to find them?
[Re E1938A] However, no "jump free" crystals were ever observed.
Do you remember what the usual rate and size of these jumps were
Len Cutler tried to construct
an ensemble of ten 10811's and operate them as a smart clock. That
would have made a great paper at FCS, if only it could be made to work.
That is another discussion...
That would be a discussion I would be very much interested to hear, as I have
been playing with the same idea on and off as well.
On Thu, 13 Mar 2025 07:15:42 +0000
Ed Marciniak via time-nuts time-nuts@lists.febo.com wrote:
Out of curiosity, how much do swept quartz blanks help?
How about ion beam milling or other processes to remove defects from surfaces?
I don't know about swept quarzes but surface defect removal is a big part of
frequency jump prevention. From what I have read, there are three general
method groups: surface defect prevention/removal, stress removal and contaminant
removal. But I do not have any numbers, how much each of those help. This wasn't
published, as far as I am aware.
Thanks again, and have a nice evening
Attila Kinali
--
Science is made up of so many things that appear obvious
after they are explained. -- Pardot Kynes
A wonderful good Sunday everyone,
Thanks for all the intersting answers.
I'm going to pick a few of the points made and add some comments.
I'll do this in one mail, as not to clutter the mailinglist too much.
On Wed, 12 Mar 2025 16:21:33 -0400
Bob Camp via time-nuts <time-nuts@lists.febo.com> wrote:
> The main “issue” in terms of a lack of papers seems to be that the tie between cause and effect still
> is in the “maybe” category. Over the years, the magnitude of the jumps *has* dropped. Folks are fixing
> something. Most likely they are fixing a number of things that each can create a jump. Tying each change
> to this or that maybe 5 or 10% improvement …. good luck.
So, we still have this issue, but as people run out of ideas how to fix it,
they just chose to live with it as well as they can?
On Wed, 12 Mar 2025 14:45:57 -0700
Richard Karlquist via time-nuts <time-nuts@lists.febo.com> wrote:
> The method
> used to "improve" aging consisted of burning in crystals on an "ager"
> system and shipping oscillators (containing crystals) when they achieved
> the aging spec they needed.
How did this ager look like? Was it just the bare crystal package in a
bread-board like oscillator, attached to some frequency counter to measure
it's long term behavior?
> I remember when I first got involved in
> crystal oscillators around 1973, before I worked for HP, I was
> introduced to crystals from "Colorado Crystal" that were packaged in
> glass packages. Their frequency aging was mostly or completely in the
> positive direction (higher frequency as time passed). Conventional
> metal packages mostly were negative aging. This was explained to be me
> by the fact that glass didn't outgass anything that would land on the
> resonator and lower its frequency.
I have looked at data from ultra high vacuum (UHV) systems and I am pretty sure
that this theory is not fully correct. While it is true that metal surfaces
are full of water and hydrocarbons and that they require proper cleaning
and out-gasing procedure prior to use in UHV systems, glass is even more
porous and contains quite a bit of content that can outgas (technical
glasses used in UHV have about the same outgasing performance as metals).
I think that the biggest difference is, that glass is more "sticky" for the
larger molecules (i.e. hydrocarbons) than quartz, thus the equilibrium
point of these molecules sticking to surfaces shifts towards them sticking more
to glass than the crystal, thus making the crystal surface lighter.
I have also been told (by either by John Vig or Gregory Weaver), that glass
packages in space perform much better than metal packages in space, while
on earth the difference is not significant (probably after applying all types
of cleaning before sealing). This suggests, that glass is porous enough that
smaller contaminants (single atomic and di-atomic gasses, water,..) can get
through the glass and outgas into space. But I have not seen any data that
would support this, nor have I been told about any real measuruement that
would support this hypothesis.
> Also, Jack was busy giving private training classes to numerous crystal
> fabricators so that we could establish alternative crystal oscillator
> sources.
I have been told a few times about this quest of Jack Kusters', but I could
not find any documentation thereof. Do you know whether some form of written
document from these training sessions are left and maybe even where to find them?
> [Re E1938A] However, no "jump free" crystals were ever observed.
Do you remember what the usual rate and size of these jumps were
> Len Cutler tried to construct
> an ensemble of ten 10811's and operate them as a smart clock. That
> would have made a great paper at FCS, if only it could be made to work.
> That is another discussion...
That would be a discussion I would be very much interested to hear, as I have
been playing with the same idea on and off as well.
On Thu, 13 Mar 2025 07:15:42 +0000
Ed Marciniak via time-nuts <time-nuts@lists.febo.com> wrote:
> Out of curiosity, how much do swept quartz blanks help?
> How about ion beam milling or other processes to remove defects from surfaces?
I don't know about swept quarzes but surface defect removal is a big part of
frequency jump prevention. From what I have read, there are three general
method groups: surface defect prevention/removal, stress removal and contaminant
removal. But I do not have any numbers, how much each of those help. This wasn't
published, as far as I am aware.
Thanks again, and have a nice evening
Attila Kinali
--
Science is made up of so many things that appear obvious
after they are explained. -- Pardot Kynes
MD
Magnus Danielson
Sun, Mar 16, 2025 10:26 PM
Hi Attila,
I recall one paper on the BVA where they built a rather large "chimney"
with large cross-area for the bake-out at high temperature and vacuum
pump. The large area helps for ultrahigh vacuum pumping. I think I
recall 200 degrees C and long baking time to evaporate out as much
contaminants as possible. At the end of the bake-out they use the
chimney as a pinch-off.
Cheers,
Magnus
On 2025-03-16 22:06, Attila Kinali via time-nuts wrote:
A wonderful good Sunday everyone,
Thanks for all the intersting answers.
I'm going to pick a few of the points made and add some comments.
I'll do this in one mail, as not to clutter the mailinglist too much.
On Wed, 12 Mar 2025 16:21:33 -0400
Bob Camp via time-nuts time-nuts@lists.febo.com wrote:
The main “issue” in terms of a lack of papers seems to be that the tie between cause and effect still
is in the “maybe” category. Over the years, the magnitude of the jumps has dropped. Folks are fixing
something. Most likely they are fixing a number of things that each can create a jump. Tying each change
to this or that maybe 5 or 10% improvement …. good luck.
So, we still have this issue, but as people run out of ideas how to fix it,
they just chose to live with it as well as they can?
On Wed, 12 Mar 2025 14:45:57 -0700
Richard Karlquist via time-nuts time-nuts@lists.febo.com wrote:
The method
used to "improve" aging consisted of burning in crystals on an "ager"
system and shipping oscillators (containing crystals) when they achieved
the aging spec they needed.
How did this ager look like? Was it just the bare crystal package in a
bread-board like oscillator, attached to some frequency counter to measure
it's long term behavior?
I remember when I first got involved in
crystal oscillators around 1973, before I worked for HP, I was
introduced to crystals from "Colorado Crystal" that were packaged in
glass packages. Their frequency aging was mostly or completely in the
positive direction (higher frequency as time passed). Conventional
metal packages mostly were negative aging. This was explained to be me
by the fact that glass didn't outgass anything that would land on the
resonator and lower its frequency.
I have looked at data from ultra high vacuum (UHV) systems and I am pretty sure
that this theory is not fully correct. While it is true that metal surfaces
are full of water and hydrocarbons and that they require proper cleaning
and out-gasing procedure prior to use in UHV systems, glass is even more
porous and contains quite a bit of content that can outgas (technical
glasses used in UHV have about the same outgasing performance as metals).
I think that the biggest difference is, that glass is more "sticky" for the
larger molecules (i.e. hydrocarbons) than quartz, thus the equilibrium
point of these molecules sticking to surfaces shifts towards them sticking more
to glass than the crystal, thus making the crystal surface lighter.
I have also been told (by either by John Vig or Gregory Weaver), that glass
packages in space perform much better than metal packages in space, while
on earth the difference is not significant (probably after applying all types
of cleaning before sealing). This suggests, that glass is porous enough that
smaller contaminants (single atomic and di-atomic gasses, water,..) can get
through the glass and outgas into space. But I have not seen any data that
would support this, nor have I been told about any real measuruement that
would support this hypothesis.
Also, Jack was busy giving private training classes to numerous crystal
fabricators so that we could establish alternative crystal oscillator
sources.
I have been told a few times about this quest of Jack Kusters', but I could
not find any documentation thereof. Do you know whether some form of written
document from these training sessions are left and maybe even where to find them?
[Re E1938A] However, no "jump free" crystals were ever observed.
Do you remember what the usual rate and size of these jumps were
Len Cutler tried to construct
an ensemble of ten 10811's and operate them as a smart clock. That
would have made a great paper at FCS, if only it could be made to work.
That is another discussion...
That would be a discussion I would be very much interested to hear, as I have
been playing with the same idea on and off as well.
On Thu, 13 Mar 2025 07:15:42 +0000
Ed Marciniak via time-nuts time-nuts@lists.febo.com wrote:
Out of curiosity, how much do swept quartz blanks help?
How about ion beam milling or other processes to remove defects from surfaces?
I don't know about swept quarzes but surface defect removal is a big part of
frequency jump prevention. From what I have read, there are three general
method groups: surface defect prevention/removal, stress removal and contaminant
removal. But I do not have any numbers, how much each of those help. This wasn't
published, as far as I am aware.
Thanks again, and have a nice evening
Attila Kinali
Hi Attila,
I recall one paper on the BVA where they built a rather large "chimney"
with large cross-area for the bake-out at high temperature and vacuum
pump. The large area helps for ultrahigh vacuum pumping. I think I
recall 200 degrees C and long baking time to evaporate out as much
contaminants as possible. At the end of the bake-out they use the
chimney as a pinch-off.
Cheers,
Magnus
On 2025-03-16 22:06, Attila Kinali via time-nuts wrote:
> A wonderful good Sunday everyone,
>
> Thanks for all the intersting answers.
>
> I'm going to pick a few of the points made and add some comments.
> I'll do this in one mail, as not to clutter the mailinglist too much.
>
> On Wed, 12 Mar 2025 16:21:33 -0400
> Bob Camp via time-nuts <time-nuts@lists.febo.com> wrote:
>
>> The main “issue” in terms of a lack of papers seems to be that the tie between cause and effect still
>> is in the “maybe” category. Over the years, the magnitude of the jumps *has* dropped. Folks are fixing
>> something. Most likely they are fixing a number of things that each can create a jump. Tying each change
>> to this or that maybe 5 or 10% improvement …. good luck.
> So, we still have this issue, but as people run out of ideas how to fix it,
> they just chose to live with it as well as they can?
>
>
> On Wed, 12 Mar 2025 14:45:57 -0700
> Richard Karlquist via time-nuts <time-nuts@lists.febo.com> wrote:
>
>> The method
>> used to "improve" aging consisted of burning in crystals on an "ager"
>> system and shipping oscillators (containing crystals) when they achieved
>> the aging spec they needed.
> How did this ager look like? Was it just the bare crystal package in a
> bread-board like oscillator, attached to some frequency counter to measure
> it's long term behavior?
>
>> I remember when I first got involved in
>> crystal oscillators around 1973, before I worked for HP, I was
>> introduced to crystals from "Colorado Crystal" that were packaged in
>> glass packages. Their frequency aging was mostly or completely in the
>> positive direction (higher frequency as time passed). Conventional
>> metal packages mostly were negative aging. This was explained to be me
>> by the fact that glass didn't outgass anything that would land on the
>> resonator and lower its frequency.
> I have looked at data from ultra high vacuum (UHV) systems and I am pretty sure
> that this theory is not fully correct. While it is true that metal surfaces
> are full of water and hydrocarbons and that they require proper cleaning
> and out-gasing procedure prior to use in UHV systems, glass is even more
> porous and contains quite a bit of content that can outgas (technical
> glasses used in UHV have about the same outgasing performance as metals).
> I think that the biggest difference is, that glass is more "sticky" for the
> larger molecules (i.e. hydrocarbons) than quartz, thus the equilibrium
> point of these molecules sticking to surfaces shifts towards them sticking more
> to glass than the crystal, thus making the crystal surface lighter.
>
> I have also been told (by either by John Vig or Gregory Weaver), that glass
> packages in space perform much better than metal packages in space, while
> on earth the difference is not significant (probably after applying all types
> of cleaning before sealing). This suggests, that glass is porous enough that
> smaller contaminants (single atomic and di-atomic gasses, water,..) can get
> through the glass and outgas into space. But I have not seen any data that
> would support this, nor have I been told about any real measuruement that
> would support this hypothesis.
>
>
>> Also, Jack was busy giving private training classes to numerous crystal
>> fabricators so that we could establish alternative crystal oscillator
>> sources.
> I have been told a few times about this quest of Jack Kusters', but I could
> not find any documentation thereof. Do you know whether some form of written
> document from these training sessions are left and maybe even where to find them?
>
>> [Re E1938A] However, no "jump free" crystals were ever observed.
> Do you remember what the usual rate and size of these jumps were
>
>
>> Len Cutler tried to construct
>> an ensemble of ten 10811's and operate them as a smart clock. That
>> would have made a great paper at FCS, if only it could be made to work.
>> That is another discussion...
> That would be a discussion I would be very much interested to hear, as I have
> been playing with the same idea on and off as well.
>
> On Thu, 13 Mar 2025 07:15:42 +0000
> Ed Marciniak via time-nuts <time-nuts@lists.febo.com> wrote:
>
>> Out of curiosity, how much do swept quartz blanks help?
>> How about ion beam milling or other processes to remove defects from surfaces?
> I don't know about swept quarzes but surface defect removal is a big part of
> frequency jump prevention. From what I have read, there are three general
> method groups: surface defect prevention/removal, stress removal and contaminant
> removal. But I do not have any numbers, how much each of those help. This wasn't
> published, as far as I am aware.
>
>
> Thanks again, and have a nice evening
>
> Attila Kinali
BC
Bob Camp
Sun, Mar 16, 2025 11:24 PM
Hi
Ok, a few more details.
No folks have not stopped working on this stuff. It simply is not very exciting. Like a lot of crystal
processing “stuff”, it’s part of the IP of the company. Those two things combine to make it not
very paper worthy.
====
As the whole HP “crystal empire” changed, Jack Kusters moved from HP and got involved
with the EMXO. The EMXO eventually moved over to Vectron. A lot of discussions went on as part
of those moves. That was on top of the work to outsource crystal production.
====
There is very little data that suggests the crystal package impacts phase jumps. Pretty much
everything points towards the blank structure / supports being the source of the problem. Like
any other “never say never’ situation, there will always be those one in a hundred issues. Still
the big deal is not the package.
Bob
On Mar 16, 2025, at 5:06 PM, Attila Kinali via time-nuts time-nuts@lists.febo.com wrote:
A wonderful good Sunday everyone,
Thanks for all the intersting answers.
I'm going to pick a few of the points made and add some comments.
I'll do this in one mail, as not to clutter the mailinglist too much.
On Wed, 12 Mar 2025 16:21:33 -0400
Bob Camp via time-nuts time-nuts@lists.febo.com wrote:
The main “issue” in terms of a lack of papers seems to be that the tie between cause and effect still
is in the “maybe” category. Over the years, the magnitude of the jumps has dropped. Folks are fixing
something. Most likely they are fixing a number of things that each can create a jump. Tying each change
to this or that maybe 5 or 10% improvement …. good luck.
So, we still have this issue, but as people run out of ideas how to fix it,
they just chose to live with it as well as they can?
On Wed, 12 Mar 2025 14:45:57 -0700
Richard Karlquist via time-nuts time-nuts@lists.febo.com wrote:
The method
used to "improve" aging consisted of burning in crystals on an "ager"
system and shipping oscillators (containing crystals) when they achieved
the aging spec they needed.
How did this ager look like? Was it just the bare crystal package in a
bread-board like oscillator, attached to some frequency counter to measure
it's long term behavior?
I remember when I first got involved in
crystal oscillators around 1973, before I worked for HP, I was
introduced to crystals from "Colorado Crystal" that were packaged in
glass packages. Their frequency aging was mostly or completely in the
positive direction (higher frequency as time passed). Conventional
metal packages mostly were negative aging. This was explained to be me
by the fact that glass didn't outgass anything that would land on the
resonator and lower its frequency.
I have looked at data from ultra high vacuum (UHV) systems and I am pretty sure
that this theory is not fully correct. While it is true that metal surfaces
are full of water and hydrocarbons and that they require proper cleaning
and out-gasing procedure prior to use in UHV systems, glass is even more
porous and contains quite a bit of content that can outgas (technical
glasses used in UHV have about the same outgasing performance as metals).
I think that the biggest difference is, that glass is more "sticky" for the
larger molecules (i.e. hydrocarbons) than quartz, thus the equilibrium
point of these molecules sticking to surfaces shifts towards them sticking more
to glass than the crystal, thus making the crystal surface lighter.
I have also been told (by either by John Vig or Gregory Weaver), that glass
packages in space perform much better than metal packages in space, while
on earth the difference is not significant (probably after applying all types
of cleaning before sealing). This suggests, that glass is porous enough that
smaller contaminants (single atomic and di-atomic gasses, water,..) can get
through the glass and outgas into space. But I have not seen any data that
would support this, nor have I been told about any real measuruement that
would support this hypothesis.
Also, Jack was busy giving private training classes to numerous crystal
fabricators so that we could establish alternative crystal oscillator
sources.
I have been told a few times about this quest of Jack Kusters', but I could
not find any documentation thereof. Do you know whether some form of written
document from these training sessions are left and maybe even where to find them?
[Re E1938A] However, no "jump free" crystals were ever observed.
Do you remember what the usual rate and size of these jumps were
Len Cutler tried to construct
an ensemble of ten 10811's and operate them as a smart clock. That
would have made a great paper at FCS, if only it could be made to work.
That is another discussion...
That would be a discussion I would be very much interested to hear, as I have
been playing with the same idea on and off as well.
On Thu, 13 Mar 2025 07:15:42 +0000
Ed Marciniak via time-nuts time-nuts@lists.febo.com wrote:
Out of curiosity, how much do swept quartz blanks help?
How about ion beam milling or other processes to remove defects from surfaces?
I don't know about swept quarzes but surface defect removal is a big part of
frequency jump prevention. From what I have read, there are three general
method groups: surface defect prevention/removal, stress removal and contaminant
removal. But I do not have any numbers, how much each of those help. This wasn't
published, as far as I am aware.
Thanks again, and have a nice evening
Attila Kinali
--
Science is made up of so many things that appear obvious
after they are explained. -- Pardot Kynes
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe send an email to time-nuts-leave@lists.febo.com
Hi
Ok, a few more details.
No folks have not stopped working on this stuff. It simply is not very exciting. Like a lot of crystal
processing “stuff”, it’s part of the IP of the company. Those two things combine to make it not
very paper worthy.
====
As the whole HP “crystal empire” changed, Jack Kusters moved from HP and got involved
with the EMXO. The EMXO eventually moved over to Vectron. A lot of discussions went on as part
of those moves. That was on top of the work to outsource crystal production.
====
There is very little data that suggests the crystal package impacts phase jumps. Pretty much
everything points towards the blank structure / supports being the source of the problem. Like
any other “never say never’ situation, there will always be those one in a hundred issues. Still
the big deal is not the package.
Bob
> On Mar 16, 2025, at 5:06 PM, Attila Kinali via time-nuts <time-nuts@lists.febo.com> wrote:
>
> A wonderful good Sunday everyone,
>
> Thanks for all the intersting answers.
>
> I'm going to pick a few of the points made and add some comments.
> I'll do this in one mail, as not to clutter the mailinglist too much.
>
> On Wed, 12 Mar 2025 16:21:33 -0400
> Bob Camp via time-nuts <time-nuts@lists.febo.com> wrote:
>
>> The main “issue” in terms of a lack of papers seems to be that the tie between cause and effect still
>> is in the “maybe” category. Over the years, the magnitude of the jumps *has* dropped. Folks are fixing
>> something. Most likely they are fixing a number of things that each can create a jump. Tying each change
>> to this or that maybe 5 or 10% improvement …. good luck.
>
> So, we still have this issue, but as people run out of ideas how to fix it,
> they just chose to live with it as well as they can?
>
>
> On Wed, 12 Mar 2025 14:45:57 -0700
> Richard Karlquist via time-nuts <time-nuts@lists.febo.com> wrote:
>
>> The method
>> used to "improve" aging consisted of burning in crystals on an "ager"
>> system and shipping oscillators (containing crystals) when they achieved
>> the aging spec they needed.
>
> How did this ager look like? Was it just the bare crystal package in a
> bread-board like oscillator, attached to some frequency counter to measure
> it's long term behavior?
>
>> I remember when I first got involved in
>> crystal oscillators around 1973, before I worked for HP, I was
>> introduced to crystals from "Colorado Crystal" that were packaged in
>> glass packages. Their frequency aging was mostly or completely in the
>> positive direction (higher frequency as time passed). Conventional
>> metal packages mostly were negative aging. This was explained to be me
>> by the fact that glass didn't outgass anything that would land on the
>> resonator and lower its frequency.
>
> I have looked at data from ultra high vacuum (UHV) systems and I am pretty sure
> that this theory is not fully correct. While it is true that metal surfaces
> are full of water and hydrocarbons and that they require proper cleaning
> and out-gasing procedure prior to use in UHV systems, glass is even more
> porous and contains quite a bit of content that can outgas (technical
> glasses used in UHV have about the same outgasing performance as metals).
> I think that the biggest difference is, that glass is more "sticky" for the
> larger molecules (i.e. hydrocarbons) than quartz, thus the equilibrium
> point of these molecules sticking to surfaces shifts towards them sticking more
> to glass than the crystal, thus making the crystal surface lighter.
>
> I have also been told (by either by John Vig or Gregory Weaver), that glass
> packages in space perform much better than metal packages in space, while
> on earth the difference is not significant (probably after applying all types
> of cleaning before sealing). This suggests, that glass is porous enough that
> smaller contaminants (single atomic and di-atomic gasses, water,..) can get
> through the glass and outgas into space. But I have not seen any data that
> would support this, nor have I been told about any real measuruement that
> would support this hypothesis.
>
>
>> Also, Jack was busy giving private training classes to numerous crystal
>> fabricators so that we could establish alternative crystal oscillator
>> sources.
>
> I have been told a few times about this quest of Jack Kusters', but I could
> not find any documentation thereof. Do you know whether some form of written
> document from these training sessions are left and maybe even where to find them?
>
>> [Re E1938A] However, no "jump free" crystals were ever observed.
>
> Do you remember what the usual rate and size of these jumps were
>
>
>> Len Cutler tried to construct
>> an ensemble of ten 10811's and operate them as a smart clock. That
>> would have made a great paper at FCS, if only it could be made to work.
>> That is another discussion...
>
> That would be a discussion I would be very much interested to hear, as I have
> been playing with the same idea on and off as well.
>
> On Thu, 13 Mar 2025 07:15:42 +0000
> Ed Marciniak via time-nuts <time-nuts@lists.febo.com> wrote:
>
>> Out of curiosity, how much do swept quartz blanks help?
>> How about ion beam milling or other processes to remove defects from surfaces?
>
> I don't know about swept quarzes but surface defect removal is a big part of
> frequency jump prevention. From what I have read, there are three general
> method groups: surface defect prevention/removal, stress removal and contaminant
> removal. But I do not have any numbers, how much each of those help. This wasn't
> published, as far as I am aware.
>
>
> Thanks again, and have a nice evening
>
> Attila Kinali
> --
> Science is made up of so many things that appear obvious
> after they are explained. -- Pardot Kynes
> _______________________________________________
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> To unsubscribe send an email to time-nuts-leave@lists.febo.com
JL
Jim Lux
Mon, Mar 17, 2025 4:09 PM
Some other responses, interspersed (and snipped out of)
On Sun, 16 Mar 2025 22:06:34 +0100, Attila Kinali via time-nuts time-nuts@lists.febo.com wrote:
On Wed, 12 Mar 2025 16:21:33 -0400
Bob Camp via time-nuts wrote:
The main “issue” in terms of a lack of papers seems to be that the tie between cause and effect still
is in the “maybe” category. Over the years, the magnitude of the jumps has dropped. Folks are fixing
something. Most likely they are fixing a number of things that each can create a jump. Tying each change
to this or that maybe 5 or 10% improvement …. good luck.
So, we still have this issue, but as people run out of ideas how to fix it,
they just chose to live with it as well as they can?
pretty much - Techniques like GPSDO and other inexpensive devices like the CSAC fill the need. The ones that aren't filled - live with it.
On Wed, 12 Mar 2025 14:45:57 -0700
Richard Karlquist via time-nuts wrote:
The method
used to "improve" aging consisted of burning in crystals on an "ager"
system and shipping oscillators (containing crystals) when they achieved
the aging spec they needed.
How did this ager look like? Was it just the bare crystal package in a
bread-board like oscillator, attached to some frequency counter to measure
it's long term behavior?
I know that for Ultra Stable Oscillators for spaceflight they have a bunch of the physics packages (oscillator circuit with crystal, in the flight dewar flask, with the temperature control circuitry) and exactly that - they run them to a counter and watch them. For the USOs for GRAIL (at the Moon), ultimately needing 2 (or 4) and spares, I seem to recall they had a couple dozen oscillators being aged, and there's a whole art to "how do you pick". Then the chosen few get fully integrated into the entire flight subsystem which is then run through environmental tests and delivered to the spacecraft (2 of them for GRAIL) for integration. I can't recall if all the physics packages went through some sort of environmental tests before aging - probably: you don't want to spend a year aging them and have one fail during aging.
I have also been told (by either by John Vig or Gregory Weaver), that glass
packages in space perform much better than metal packages in space, while
on earth the difference is not significant (probably after applying all types
of cleaning before sealing). This suggests, that glass is porous enough that
smaller contaminants (single atomic and di-atomic gasses, water,..) can get
through the glass and outgas into space. But I have not seen any data that
would support this, nor have I been told about any real measuruement that
would support this hypothesis.
This is something of some concern with seals of all kinds - He can leak in. The space station's atmosphere has a lot of He in it (the cargo ships going up are backfilled with He, so when they dock and open the hatch, there's a big bolus of He, and it's not like station is "ventilated" in the normal scheme of things). It is theorized that this was the problem that caused the restricted temperature range for the CSACs for a while - that something inside outgassed and "filled up" the getter. There were some concerns on one of the ELaNa XIX's cubesats that perhaps it had been "poisoned" by being stored in a high He environment while waiting for launch. I can't remember off hand which one it was (CHOMPTT possibly?) I will say that the CSAC on my spacecraft on that launch seemed to work exactly as expected.
Space is a MUCH better vacuum (~1E-13 Torr) than any run of the mill vacuum system used for testing. UHV systems are ~1E-8 Torr. When we do thermal vacuum testing, we get down to 1E-6 Torr, although it does fluctuate during a run (when you go cold, stuff condenses on the radiators, then when you go warm, it boils off, and you get a spike in the chamber pressure). In general, the goal in TVAC testing is getting low enough that the atmosphere in the chamber doesn't materially contribute to thermal management, and also to boil off any residual volatiles (e.g. spend at least 3 hours at 70C or 6 hours at 60C temperature at a pressure below 1E-4 Torr). Generally, you can meet the bakeout requirement in the course of the traditional 3 cycles hot and cold (although not always.. maybe your device can't tolerate 60C?). So then you rely on residual pressure measurements over time - show that there's nothing more coming out of the system by looking at the exponential decay of chamber pressure (which, of course, is being continuously pumped, so ...)
Len Cutler tried to construct
an ensemble of ten 10811's and operate them as a smart clock. That
would have made a great paper at FCS, if only it could be made to work.
That is another discussion...
That would be a discussion I would be very much interested to hear, as I have
been playing with the same idea on and off as well.
On stress removal - I've been told that for USOs, there are people who are really good at installing the crystals into the holder in terms of minimizing residual stresses, and some who aren't. It's sort of a "innate talent" apparently, and not readily trainable. (There's lots of this around - installing the permanent magnets to "focus" a TWT is the same - some techs are good at it, others not - Scientific glass blowing as well.)
There is a paper with, I think, 8 clocks in various orientations all hooked together. Not 10811s.
Some other responses, interspersed (and snipped out of)
On Sun, 16 Mar 2025 22:06:34 +0100, Attila Kinali via time-nuts <time-nuts@lists.febo.com> wrote:
On Wed, 12 Mar 2025 16:21:33 -0400
Bob Camp via time-nuts wrote:
> The main “issue” in terms of a lack of papers seems to be that the tie between cause and effect still
> is in the “maybe” category. Over the years, the magnitude of the jumps *has* dropped. Folks are fixing
> something. Most likely they are fixing a number of things that each can create a jump. Tying each change
> to this or that maybe 5 or 10% improvement …. good luck.
So, we still have this issue, but as people run out of ideas how to fix it,
they just chose to live with it as well as they can?
>>> pretty much - Techniques like GPSDO and other inexpensive devices like the CSAC fill the need. The ones that aren't filled - live with it.
On Wed, 12 Mar 2025 14:45:57 -0700
Richard Karlquist via time-nuts wrote:
> The method
> used to "improve" aging consisted of burning in crystals on an "ager"
> system and shipping oscillators (containing crystals) when they achieved
> the aging spec they needed.
How did this ager look like? Was it just the bare crystal package in a
bread-board like oscillator, attached to some frequency counter to measure
it's long term behavior?
>>> I know that for Ultra Stable Oscillators for spaceflight they have a bunch of the physics packages (oscillator circuit with crystal, in the flight dewar flask, with the temperature control circuitry) and exactly that - they run them to a counter and watch them. For the USOs for GRAIL (at the Moon), ultimately needing 2 (or 4) and spares, I seem to recall they had a couple dozen oscillators being aged, and there's a whole art to "how do you pick". Then the chosen few get fully integrated into the entire flight subsystem which is then run through environmental tests and delivered to the spacecraft (2 of them for GRAIL) for integration. I can't recall if all the physics packages went through some sort of environmental tests before aging - probably: you don't want to spend a year aging them and have one fail during aging.
I have also been told (by either by John Vig or Gregory Weaver), that glass
packages in space perform much better than metal packages in space, while
on earth the difference is not significant (probably after applying all types
of cleaning before sealing). This suggests, that glass is porous enough that
smaller contaminants (single atomic and di-atomic gasses, water,..) can get
through the glass and outgas into space. But I have not seen any data that
would support this, nor have I been told about any real measuruement that
would support this hypothesis.
>>> This is something of some concern with seals of all kinds - He can leak in. The space station's atmosphere has a lot of He in it (the cargo ships going up are backfilled with He, so when they dock and open the hatch, there's a big bolus of He, and it's not like station is "ventilated" in the normal scheme of things). It is theorized that this was the problem that caused the restricted temperature range for the CSACs for a while - that something inside outgassed and "filled up" the getter. There were some concerns on one of the ELaNa XIX's cubesats that perhaps it had been "poisoned" by being stored in a high He environment while waiting for launch. I can't remember off hand which one it was (CHOMPTT possibly?) I will say that the CSAC on my spacecraft on that launch seemed to work exactly as expected.
>>> Space is a MUCH better vacuum (~1E-13 Torr) than any run of the mill vacuum system used for testing. UHV systems are ~1E-8 Torr. When we do thermal vacuum testing, we get down to 1E-6 Torr, although it does fluctuate during a run (when you go cold, stuff condenses on the radiators, then when you go warm, it boils off, and you get a spike in the chamber pressure). In general, the goal in TVAC testing is getting low enough that the atmosphere in the chamber doesn't materially contribute to thermal management, and also to boil off any residual volatiles (e.g. spend at least 3 hours at 70C or 6 hours at 60C temperature at a pressure below 1E-4 Torr). Generally, you can meet the bakeout requirement in the course of the traditional 3 cycles hot and cold (although not always.. maybe your device can't tolerate 60C?). So then you rely on residual pressure measurements over time - show that there's nothing more coming out of the system by looking at the exponential decay of chamber pressure (which, of course, is being continuously pumped, so ...)
> Len Cutler tried to construct
> an ensemble of ten 10811's and operate them as a smart clock. That
> would have made a great paper at FCS, if only it could be made to work.
> That is another discussion...
That would be a discussion I would be very much interested to hear, as I have
been playing with the same idea on and off as well.
>>> On stress removal - I've been told that for USOs, there are people who are really good at installing the crystals into the holder in terms of minimizing residual stresses, and some who aren't. It's sort of a "innate talent" apparently, and not readily trainable. (There's lots of this around - installing the permanent magnets to "focus" a TWT is the same - some techs are good at it, others not - Scientific glass blowing as well.)
>>> There is a paper with, I think, 8 clocks in various orientations all hooked together. Not 10811s.
MG
Mark Goldberg
Tue, Mar 25, 2025 6:55 PM
I have limited experience testing some TCXOs I got custom from a well
known supplier. As I had small orders (dozens), they did not do any
screening for jumps. I found about 10% of them exhibited either jumps
or large temperature hysteresis, another issue that is not talked
about. Frequency vs temperature with rising temperature was not the
same as with falling temperature. I just did my testing and culled the
bad ones. They would not talk about these issues except to acknowledge
they exist and they would screen them if I was buying large volumes.
Aging seemed to be correlated to the time since the last reflow as
these were SMT packaged and mounted on PCBs.
Regards,
Mark
I have limited experience testing some TCXOs I got custom from a well
known supplier. As I had small orders (dozens), they did not do any
screening for jumps. I found about 10% of them exhibited either jumps
or large temperature hysteresis, another issue that is not talked
about. Frequency vs temperature with rising temperature was not the
same as with falling temperature. I just did my testing and culled the
bad ones. They would not talk about these issues except to acknowledge
they exist and they would screen them if I was buying large volumes.
Aging seemed to be correlated to the time since the last reflow as
these were SMT packaged and mounted on PCBs.
Regards,
Mark
BC
Bob Camp
Tue, Mar 25, 2025 7:33 PM
Hi
Hysteresis tends to be rate dependent. Do a full sweep over the entire temperature range in an
hour, you get one result. Run over the same range in ten hours and the result is different. There
are a lot of applications out there. Some cycle at a “once a day over part of the range” sort of rate.
Others cycle much faster.
Post soldering drift might be called retrace. (Yes, that term gets used for several similar things ….).
It’s one of the reasons you may see folks talking about “aging after X days” in their specifications.
They want the install and power up sort of effects to damp down before the aging spec applies.
There are a whole lot of IC specs that are worded that way for pretty much the same reasons.
Since install is a one time sort of thing it’s impact may or may not be a big deal. Thermocycle after
install often helps reduce it.
Bob
On Mar 25, 2025, at 2:55 PM, Mark Goldberg via time-nuts time-nuts@lists.febo.com wrote:
I have limited experience testing some TCXOs I got custom from a well
known supplier. As I had small orders (dozens), they did not do any
screening for jumps. I found about 10% of them exhibited either jumps
or large temperature hysteresis, another issue that is not talked
about. Frequency vs temperature with rising temperature was not the
same as with falling temperature. I just did my testing and culled the
bad ones. They would not talk about these issues except to acknowledge
they exist and they would screen them if I was buying large volumes.
Aging seemed to be correlated to the time since the last reflow as
these were SMT packaged and mounted on PCBs.
Regards,
Mark
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe send an email to time-nuts-leave@lists.febo.com
Hi
Hysteresis tends to be rate dependent. Do a full sweep over the entire temperature range in an
hour, you get one result. Run over the same range in ten hours and the result is different. There
are a lot of applications out there. Some cycle at a “once a day over part of the range” sort of rate.
Others cycle much faster.
Post soldering drift might be called retrace. (Yes, that term gets used for several similar things ….).
It’s one of the reasons you may see folks talking about “aging after X days” in their specifications.
They want the install and power up sort of effects to damp down before the aging spec applies.
There are a whole lot of IC specs that are worded that way for pretty much the same reasons.
Since install is a one time sort of thing it’s impact may or may not be a big deal. Thermocycle after
install often helps reduce it.
Bob
> On Mar 25, 2025, at 2:55 PM, Mark Goldberg via time-nuts <time-nuts@lists.febo.com> wrote:
>
> I have limited experience testing some TCXOs I got custom from a well
> known supplier. As I had small orders (dozens), they did not do any
> screening for jumps. I found about 10% of them exhibited either jumps
> or large temperature hysteresis, another issue that is not talked
> about. Frequency vs temperature with rising temperature was not the
> same as with falling temperature. I just did my testing and culled the
> bad ones. They would not talk about these issues except to acknowledge
> they exist and they would screen them if I was buying large volumes.
>
> Aging seemed to be correlated to the time since the last reflow as
> these were SMT packaged and mounted on PCBs.
>
> Regards,
>
> Mark
> _______________________________________________
> time-nuts mailing list -- time-nuts@lists.febo.com
> To unsubscribe send an email to time-nuts-leave@lists.febo.com
GV
Geoff Van der Wagen
Wed, Mar 26, 2025 12:56 AM
Hi Sebastien,
I share a similar philosophy, and would also like to work on
self-contained options.
Unfortunately, I have far too many ideas and far too little time/energy
to do them!
My current wish is to make a VCOCXO and be able to discipline it in
different ways. Various options here are broadcast AM, WWV, or possibly
even picking up JJY. WWV will be problematic because of ionospheric
height changes and intermittent propagation. JJY is apparently possible
from Australia but no idea of what reliability would be like. It would
be fun to observe these signals with some confidence. Before GNSS there
used to be off-air frequency standards that would synchronise to LF
services.
I also started daydreaming about truly human-independent sources like
tracking pulsars but it rapidly becomes unachievable within reasonable
time and energy/motivation constraints.
Once I have a 10MHz reference I'd use that to run a hardware digital
clock with 7-segment displays maybe down to the millisecond, just for
fun (you'd need a high speed camera to see what time it is, but the act
of reading the time that way totally defeats the purpose which I find
amusing). Synchronising such a clock beyond NTP or GNSS becomes a whole
exercise in itself. Realistically, GNSS is the best way to get accurate
time. But buying a cheap GPSDO and plugging it in isn't very rewarding,
nor do I learn anything useful.
I was impressed by the ability of WSJT-x to run a frequency calibration
using various sources. Using it, I found out that some of the local AM
stations are well-disciplined and others are free-running (a couple were
considerably off-frequency, 2.5ppm or so while my FT-897D's TCXO ended
up being around 1ppm off).
Cheers
Geoff VK2WA
On 13/3/25 20:24, Sebastien F4GRX via time-nuts wrote:
Hello,
We will probably regret that one day.
That's why I'm interested (as a mere amateur) by self contained
oscillators (with manual periodical recalibration while the
possibility lasts, and not just via gnss).
Sebastien
On 13/03/2025 08:07, Poul-Henning Kamp via time-nuts wrote:
Attila Kinali via time-nuts writes:
Does someone know what happened in the 90s regarding frequency jumps?
GPS disciplining ?
Almost nothing is free-wheeling any more.
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe send an email to time-nuts-leave@lists.febo.com
Hi Sebastien,
I share a similar philosophy, and would also like to work on
self-contained options.
Unfortunately, I have far too many ideas and far too little time/energy
to do them!
My current wish is to make a VCOCXO and be able to discipline it in
different ways. Various options here are broadcast AM, WWV, or possibly
even picking up JJY. WWV will be problematic because of ionospheric
height changes and intermittent propagation. JJY is apparently possible
from Australia but no idea of what reliability would be like. It would
be fun to observe these signals with some confidence. Before GNSS there
used to be off-air frequency standards that would synchronise to LF
services.
I also started daydreaming about truly human-independent sources like
tracking pulsars but it rapidly becomes unachievable within reasonable
time and energy/motivation constraints.
Once I have a 10MHz reference I'd use that to run a hardware digital
clock with 7-segment displays maybe down to the millisecond, just for
fun (you'd need a high speed camera to see what time it is, but the act
of reading the time that way totally defeats the purpose which I find
amusing). Synchronising such a clock beyond NTP or GNSS becomes a whole
exercise in itself. Realistically, GNSS is the best way to get accurate
time. But buying a cheap GPSDO and plugging it in isn't very rewarding,
nor do I learn anything useful.
I was impressed by the ability of WSJT-x to run a frequency calibration
using various sources. Using it, I found out that some of the local AM
stations are well-disciplined and others are free-running (a couple were
considerably off-frequency, 2.5ppm or so while my FT-897D's TCXO ended
up being around 1ppm off).
Cheers
Geoff VK2WA
On 13/3/25 20:24, Sebastien F4GRX via time-nuts wrote:
> Hello,
>
> We will probably regret that one day.
>
> That's why I'm interested (as a mere amateur) by self contained
> oscillators (with manual periodical recalibration while the
> possibility lasts, and not just via gnss).
>
> Sebastien
>
>
> On 13/03/2025 08:07, Poul-Henning Kamp via time-nuts wrote:
>> --------
>> Attila Kinali via time-nuts writes:
>>
>>
>>> Does someone know what happened in the 90s regarding frequency jumps?
>> GPS disciplining ?
>>
>> Almost nothing is free-wheeling any more.
>>
> _______________________________________________
> time-nuts mailing list -- time-nuts@lists.febo.com
> To unsubscribe send an email to time-nuts-leave@lists.febo.com
SF
Sebastien F4GRX
Wed, Mar 26, 2025 8:44 AM
Hello Geoff,
Very happy to share some ideas. Yes, I also happen to have too many
ideas for normal 24 hour days.
In france I have the option to sync on the Allouis transmitter (formerly
France Inter AM radio), which is directly traceable to UTC and was
retained for time signals even if the audio broadcast was shut down.
That sync will happen at some point.
I also have wishes and components to build that 7-segment time display
and a plausible design for a 10 MHz PPS divider, with an option to
adjust it to UTC. The idea came after looking at Curious Marc's video
about his HP clocks.
Meanwhile I will receive tomorrow components to build a small portable
clock based on a DS1321 and a little box I found in my scrap box.
So many projects. So many distractions. haha.
At least I am happy to say that I have completed a coaxial to SFP
breakout board that can transmit a 10 MHz signal over any optical fiber.
that one was inspired by Benjojo's presentation at the CCC. At least
that project is complete and working (this is quite rare for me)
https://assets.chaos.social/media_attachments/files/114/070/817/099/369/933/original/9506286b89dda0cb.jpg
(this link may rot after sometime)
Sebastien
On 26/03/2025 01:56, Geoff Van der Wagen via time-nuts wrote:
Hi Sebastien,
I share a similar philosophy, and would also like to work on
self-contained options.
Unfortunately, I have far too many ideas and far too little
time/energy to do them!
My current wish is to make a VCOCXO and be able to discipline it in
different ways. Various options here are broadcast AM, WWV, or
possibly even picking up JJY. WWV will be problematic because of
ionospheric height changes and intermittent propagation. JJY is
apparently possible from Australia but no idea of what reliability
would be like. It would be fun to observe these signals with some
confidence. Before GNSS there used to be off-air frequency standards
that would synchronise to LF services.
I also started daydreaming about truly human-independent sources like
tracking pulsars but it rapidly becomes unachievable within reasonable
time and energy/motivation constraints.
Once I have a 10MHz reference I'd use that to run a hardware digital
clock with 7-segment displays maybe down to the millisecond, just for
fun (you'd need a high speed camera to see what time it is, but the
act of reading the time that way totally defeats the purpose which I
find amusing). Synchronising such a clock beyond NTP or GNSS becomes
a whole exercise in itself. Realistically, GNSS is the best way to get
accurate time. But buying a cheap GPSDO and plugging it in isn't very
rewarding, nor do I learn anything useful.
I was impressed by the ability of WSJT-x to run a frequency
calibration using various sources. Using it, I found out that some of
the local AM stations are well-disciplined and others are free-running
(a couple were considerably off-frequency, 2.5ppm or so while my
FT-897D's TCXO ended up being around 1ppm off).
Cheers
Geoff VK2WA
On 13/3/25 20:24, Sebastien F4GRX via time-nuts wrote:
Hello,
We will probably regret that one day.
That's why I'm interested (as a mere amateur) by self contained
oscillators (with manual periodical recalibration while the
possibility lasts, and not just via gnss).
Sebastien
On 13/03/2025 08:07, Poul-Henning Kamp via time-nuts wrote:
Attila Kinali via time-nuts writes:
Does someone know what happened in the 90s regarding frequency jumps?
GPS disciplining ?
Almost nothing is free-wheeling any more.
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe send an email to time-nuts-leave@lists.febo.com
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe send an email to time-nuts-leave@lists.febo.com
Hello Geoff,
Very happy to share some ideas. Yes, I also happen to have too many
ideas for normal 24 hour days.
In france I have the option to sync on the Allouis transmitter (formerly
France Inter AM radio), which is directly traceable to UTC and was
retained for time signals even if the audio broadcast was shut down.
That sync will happen at some point.
I also have wishes and components to build that 7-segment time display
and a plausible design for a 10 MHz PPS divider, with an option to
adjust it to UTC. The idea came after looking at Curious Marc's video
about his HP clocks.
Meanwhile I will receive tomorrow components to build a small portable
clock based on a DS1321 and a little box I found in my scrap box.
So many projects. So many distractions. haha.
At least I am happy to say that I have completed a coaxial to SFP
breakout board that can transmit a 10 MHz signal over any optical fiber.
that one was inspired by Benjojo's presentation at the CCC. At least
that project is complete and working (this is quite rare for me)
https://assets.chaos.social/media_attachments/files/114/070/817/099/369/933/original/9506286b89dda0cb.jpg
(this link may rot after sometime)
Sebastien
On 26/03/2025 01:56, Geoff Van der Wagen via time-nuts wrote:
> Hi Sebastien,
>
> I share a similar philosophy, and would also like to work on
> self-contained options.
>
> Unfortunately, I have far too many ideas and far too little
> time/energy to do them!
>
> My current wish is to make a VCOCXO and be able to discipline it in
> different ways. Various options here are broadcast AM, WWV, or
> possibly even picking up JJY. WWV will be problematic because of
> ionospheric height changes and intermittent propagation. JJY is
> apparently possible from Australia but no idea of what reliability
> would be like. It would be fun to observe these signals with some
> confidence. Before GNSS there used to be off-air frequency standards
> that would synchronise to LF services.
>
> I also started daydreaming about truly human-independent sources like
> tracking pulsars but it rapidly becomes unachievable within reasonable
> time and energy/motivation constraints.
>
> Once I have a 10MHz reference I'd use that to run a hardware digital
> clock with 7-segment displays maybe down to the millisecond, just for
> fun (you'd need a high speed camera to see what time it is, but the
> act of reading the time that way totally defeats the purpose which I
> find amusing). Synchronising such a clock beyond NTP or GNSS becomes
> a whole exercise in itself. Realistically, GNSS is the best way to get
> accurate time. But buying a cheap GPSDO and plugging it in isn't very
> rewarding, nor do I learn anything useful.
>
> I was impressed by the ability of WSJT-x to run a frequency
> calibration using various sources. Using it, I found out that some of
> the local AM stations are well-disciplined and others are free-running
> (a couple were considerably off-frequency, 2.5ppm or so while my
> FT-897D's TCXO ended up being around 1ppm off).
>
> Cheers
>
> Geoff VK2WA
>
>
> On 13/3/25 20:24, Sebastien F4GRX via time-nuts wrote:
>> Hello,
>>
>> We will probably regret that one day.
>>
>> That's why I'm interested (as a mere amateur) by self contained
>> oscillators (with manual periodical recalibration while the
>> possibility lasts, and not just via gnss).
>>
>> Sebastien
>>
>>
>> On 13/03/2025 08:07, Poul-Henning Kamp via time-nuts wrote:
>>> --------
>>> Attila Kinali via time-nuts writes:
>>>
>>>
>>>> Does someone know what happened in the 90s regarding frequency jumps?
>>> GPS disciplining ?
>>>
>>> Almost nothing is free-wheeling any more.
>>>
>> _______________________________________________
>> time-nuts mailing list -- time-nuts@lists.febo.com
>> To unsubscribe send an email to time-nuts-leave@lists.febo.com
> _______________________________________________
> time-nuts mailing list -- time-nuts@lists.febo.com
> To unsubscribe send an email to time-nuts-leave@lists.febo.com
JH
john.haine@haine-online.net
Wed, Mar 26, 2025 8:50 AM
Geoff, I'm not sure where you are located but in Europe there is of course the DCF77 signal from Mainflingen at 77.5 kHz and the MSF signal at 60 kHz from Anthorn (UK). I am fairly certain that there are still products around that use these to derive a stable frequency and time source, and there have been a number of amateur projects published. With the growing concerns over GNSS jamming and spoofing there's increasing interest in e-LORAN at 100 kHz for PNT, there is a station at Anthorn transmitting, possibly a network being set up over the UK, some I believe in Europe and (ironically) in Russia. With all these VLF standards working in similar frequency ranges a multi-standard receiver ought to be possible which could apply diversity.
Cellular base stations are extremely stable and GNSS locked, though fixed PNT networks are being deployed to remove this reliance. A standard frequency receiver based on cellular base station transmissions would be challenging but ought to be possible. After all, handsets have to lock on to the network frequency!
Digital TV broadcasts must also be very stable I would guess. These should be much easier to demod and decode as the transmissions are continuous. Receivable through cheap USB SDR sticks.
A few years back at Bristol University we had a PhD group project looking at using pulsars as a frequency source, inspired by work in Poland that actually resulted in a Pulsar Clock in a museum. Not such a mad idea, except that you have to keep switching to another pulsar as the earth rotates. Also not very portable!
-----Original Message-----
From: Geoff Van der Wagen via time-nuts time-nuts@lists.febo.com
Sent: 26 March 2025 00:57
To: Sebastien F4GRX via time-nuts time-nuts@lists.febo.com
Cc: Geoff Van der Wagen vk2wa@thenack.com
Subject: [time-nuts] Re: Quartz crystal frequency jumps
Hi Sebastien,
I share a similar philosophy, and would also like to work on self-contained options.
Unfortunately, I have far too many ideas and far too little time/energy to do them!
My current wish is to make a VCOCXO and be able to discipline it in different ways. Various options here are broadcast AM, WWV, or possibly even picking up JJY. WWV will be problematic because of ionospheric height changes and intermittent propagation. JJY is apparently possible from Australia but no idea of what reliability would be like. It would be fun to observe these signals with some confidence. Before GNSS there used to be off-air frequency standards that would synchronise to LF services.
I also started daydreaming about truly human-independent sources like tracking pulsars but it rapidly becomes unachievable within reasonable time and energy/motivation constraints.
Once I have a 10MHz reference I'd use that to run a hardware digital clock with 7-segment displays maybe down to the millisecond, just for fun (you'd need a high speed camera to see what time it is, but the act of reading the time that way totally defeats the purpose which I find amusing). Synchronising such a clock beyond NTP or GNSS becomes a whole exercise in itself. Realistically, GNSS is the best way to get accurate time. But buying a cheap GPSDO and plugging it in isn't very rewarding, nor do I learn anything useful.
I was impressed by the ability of WSJT-x to run a frequency calibration using various sources. Using it, I found out that some of the local AM stations are well-disciplined and others are free-running (a couple were considerably off-frequency, 2.5ppm or so while my FT-897D's TCXO ended up being around 1ppm off).
Cheers
Geoff VK2WA
On 13/3/25 20:24, Sebastien F4GRX via time-nuts wrote:
Hello,
We will probably regret that one day.
That's why I'm interested (as a mere amateur) by self contained
oscillators (with manual periodical recalibration while the
possibility lasts, and not just via gnss).
Sebastien
On 13/03/2025 08:07, Poul-Henning Kamp via time-nuts wrote:
Attila Kinali via time-nuts writes:
Does someone know what happened in the 90s regarding frequency jumps?
GPS disciplining ?
Almost nothing is free-wheeling any more.
Geoff, I'm not sure where you are located but in Europe there is of course the DCF77 signal from Mainflingen at 77.5 kHz and the MSF signal at 60 kHz from Anthorn (UK). I am fairly certain that there are still products around that use these to derive a stable frequency and time source, and there have been a number of amateur projects published. With the growing concerns over GNSS jamming and spoofing there's increasing interest in e-LORAN at 100 kHz for PNT, there is a station at Anthorn transmitting, possibly a network being set up over the UK, some I believe in Europe and (ironically) in Russia. With all these VLF standards working in similar frequency ranges a multi-standard receiver ought to be possible which could apply diversity.
Cellular base stations are extremely stable and GNSS locked, though fixed PNT networks are being deployed to remove this reliance. A standard frequency receiver based on cellular base station transmissions would be challenging but ought to be possible. After all, handsets have to lock on to the network frequency!
Digital TV broadcasts must also be very stable I would guess. These should be much easier to demod and decode as the transmissions are continuous. Receivable through cheap USB SDR sticks.
A few years back at Bristol University we had a PhD group project looking at using pulsars as a frequency source, inspired by work in Poland that actually resulted in a Pulsar Clock in a museum. Not such a mad idea, except that you have to keep switching to another pulsar as the earth rotates. Also not very portable!
-----Original Message-----
From: Geoff Van der Wagen via time-nuts <time-nuts@lists.febo.com>
Sent: 26 March 2025 00:57
To: Sebastien F4GRX via time-nuts <time-nuts@lists.febo.com>
Cc: Geoff Van der Wagen <vk2wa@thenack.com>
Subject: [time-nuts] Re: Quartz crystal frequency jumps
Hi Sebastien,
I share a similar philosophy, and would also like to work on self-contained options.
Unfortunately, I have far too many ideas and far too little time/energy to do them!
My current wish is to make a VCOCXO and be able to discipline it in different ways. Various options here are broadcast AM, WWV, or possibly even picking up JJY. WWV will be problematic because of ionospheric height changes and intermittent propagation. JJY is apparently possible from Australia but no idea of what reliability would be like. It would be fun to observe these signals with some confidence. Before GNSS there used to be off-air frequency standards that would synchronise to LF services.
I also started daydreaming about truly human-independent sources like tracking pulsars but it rapidly becomes unachievable within reasonable time and energy/motivation constraints.
Once I have a 10MHz reference I'd use that to run a hardware digital clock with 7-segment displays maybe down to the millisecond, just for fun (you'd need a high speed camera to see what time it is, but the act of reading the time that way totally defeats the purpose which I find amusing). Synchronising such a clock beyond NTP or GNSS becomes a whole exercise in itself. Realistically, GNSS is the best way to get accurate time. But buying a cheap GPSDO and plugging it in isn't very rewarding, nor do I learn anything useful.
I was impressed by the ability of WSJT-x to run a frequency calibration using various sources. Using it, I found out that some of the local AM stations are well-disciplined and others are free-running (a couple were considerably off-frequency, 2.5ppm or so while my FT-897D's TCXO ended up being around 1ppm off).
Cheers
Geoff VK2WA
On 13/3/25 20:24, Sebastien F4GRX via time-nuts wrote:
> Hello,
>
> We will probably regret that one day.
>
> That's why I'm interested (as a mere amateur) by self contained
> oscillators (with manual periodical recalibration while the
> possibility lasts, and not just via gnss).
>
> Sebastien
>
>
> On 13/03/2025 08:07, Poul-Henning Kamp via time-nuts wrote:
>> --------
>> Attila Kinali via time-nuts writes:
>>
>>
>>> Does someone know what happened in the 90s regarding frequency jumps?
>> GPS disciplining ?
>>
>> Almost nothing is free-wheeling any more.
>>
> _______________________________________________
> time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe send
> an email to time-nuts-leave@lists.febo.com
_______________________________________________
time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe send an email to time-nuts-leave@lists.febo.com
BC
Bob Camp
Wed, Mar 26, 2025 12:38 PM
Hi
Be careful with cellular networks. Some networks in some countries may not be a good source of time. Yes, that’s weird. There are all sorts of very strange stories behind each twist and turn that created that situation.
Bob
On Mar 26, 2025, at 4:50 AM, john.haine--- via time-nuts time-nuts@lists.febo.com wrote:
Geoff, I'm not sure where you are located but in Europe there is of course the DCF77 signal from Mainflingen at 77.5 kHz and the MSF signal at 60 kHz from Anthorn (UK). I am fairly certain that there are still products around that use these to derive a stable frequency and time source, and there have been a number of amateur projects published. With the growing concerns over GNSS jamming and spoofing there's increasing interest in e-LORAN at 100 kHz for PNT, there is a station at Anthorn transmitting, possibly a network being set up over the UK, some I believe in Europe and (ironically) in Russia. With all these VLF standards working in similar frequency ranges a multi-standard receiver ought to be possible which could apply diversity.
Cellular base stations are extremely stable and GNSS locked, though fixed PNT networks are being deployed to remove this reliance. A standard frequency receiver based on cellular base station transmissions would be challenging but ought to be possible. After all, handsets have to lock on to the network frequency!
Digital TV broadcasts must also be very stable I would guess. These should be much easier to demod and decode as the transmissions are continuous. Receivable through cheap USB SDR sticks.
A few years back at Bristol University we had a PhD group project looking at using pulsars as a frequency source, inspired by work in Poland that actually resulted in a Pulsar Clock in a museum. Not such a mad idea, except that you have to keep switching to another pulsar as the earth rotates. Also not very portable!
-----Original Message-----
From: Geoff Van der Wagen via time-nuts time-nuts@lists.febo.com
Sent: 26 March 2025 00:57
To: Sebastien F4GRX via time-nuts time-nuts@lists.febo.com
Cc: Geoff Van der Wagen vk2wa@thenack.com
Subject: [time-nuts] Re: Quartz crystal frequency jumps
Hi Sebastien,
I share a similar philosophy, and would also like to work on self-contained options.
Unfortunately, I have far too many ideas and far too little time/energy to do them!
My current wish is to make a VCOCXO and be able to discipline it in different ways. Various options here are broadcast AM, WWV, or possibly even picking up JJY. WWV will be problematic because of ionospheric height changes and intermittent propagation. JJY is apparently possible from Australia but no idea of what reliability would be like. It would be fun to observe these signals with some confidence. Before GNSS there used to be off-air frequency standards that would synchronise to LF services.
I also started daydreaming about truly human-independent sources like tracking pulsars but it rapidly becomes unachievable within reasonable time and energy/motivation constraints.
Once I have a 10MHz reference I'd use that to run a hardware digital clock with 7-segment displays maybe down to the millisecond, just for fun (you'd need a high speed camera to see what time it is, but the act of reading the time that way totally defeats the purpose which I find amusing). Synchronising such a clock beyond NTP or GNSS becomes a whole exercise in itself. Realistically, GNSS is the best way to get accurate time. But buying a cheap GPSDO and plugging it in isn't very rewarding, nor do I learn anything useful.
I was impressed by the ability of WSJT-x to run a frequency calibration using various sources. Using it, I found out that some of the local AM stations are well-disciplined and others are free-running (a couple were considerably off-frequency, 2.5ppm or so while my FT-897D's TCXO ended up being around 1ppm off).
Cheers
Geoff VK2WA
On 13/3/25 20:24, Sebastien F4GRX via time-nuts wrote:
Hello,
We will probably regret that one day.
That's why I'm interested (as a mere amateur) by self contained
oscillators (with manual periodical recalibration while the
possibility lasts, and not just via gnss).
Sebastien
On 13/03/2025 08:07, Poul-Henning Kamp via time-nuts wrote:
Attila Kinali via time-nuts writes:
Does someone know what happened in the 90s regarding frequency jumps?
GPS disciplining ?
Almost nothing is free-wheeling any more.
Hi
Be careful with cellular networks. Some networks in some countries may not be a good source of time. Yes, that’s weird. There are all sorts of *very* strange stories behind each twist and turn that created that situation.
Bob
> On Mar 26, 2025, at 4:50 AM, john.haine--- via time-nuts <time-nuts@lists.febo.com> wrote:
>
> Geoff, I'm not sure where you are located but in Europe there is of course the DCF77 signal from Mainflingen at 77.5 kHz and the MSF signal at 60 kHz from Anthorn (UK). I am fairly certain that there are still products around that use these to derive a stable frequency and time source, and there have been a number of amateur projects published. With the growing concerns over GNSS jamming and spoofing there's increasing interest in e-LORAN at 100 kHz for PNT, there is a station at Anthorn transmitting, possibly a network being set up over the UK, some I believe in Europe and (ironically) in Russia. With all these VLF standards working in similar frequency ranges a multi-standard receiver ought to be possible which could apply diversity.
>
> Cellular base stations are extremely stable and GNSS locked, though fixed PNT networks are being deployed to remove this reliance. A standard frequency receiver based on cellular base station transmissions would be challenging but ought to be possible. After all, handsets have to lock on to the network frequency!
>
> Digital TV broadcasts must also be very stable I would guess. These should be much easier to demod and decode as the transmissions are continuous. Receivable through cheap USB SDR sticks.
>
> A few years back at Bristol University we had a PhD group project looking at using pulsars as a frequency source, inspired by work in Poland that actually resulted in a Pulsar Clock in a museum. Not such a mad idea, except that you have to keep switching to another pulsar as the earth rotates. Also not very portable!
>
> -----Original Message-----
> From: Geoff Van der Wagen via time-nuts <time-nuts@lists.febo.com>
> Sent: 26 March 2025 00:57
> To: Sebastien F4GRX via time-nuts <time-nuts@lists.febo.com>
> Cc: Geoff Van der Wagen <vk2wa@thenack.com>
> Subject: [time-nuts] Re: Quartz crystal frequency jumps
>
> Hi Sebastien,
>
> I share a similar philosophy, and would also like to work on self-contained options.
>
> Unfortunately, I have far too many ideas and far too little time/energy to do them!
>
> My current wish is to make a VCOCXO and be able to discipline it in different ways. Various options here are broadcast AM, WWV, or possibly even picking up JJY. WWV will be problematic because of ionospheric height changes and intermittent propagation. JJY is apparently possible from Australia but no idea of what reliability would be like. It would be fun to observe these signals with some confidence. Before GNSS there used to be off-air frequency standards that would synchronise to LF services.
>
> I also started daydreaming about truly human-independent sources like tracking pulsars but it rapidly becomes unachievable within reasonable time and energy/motivation constraints.
>
> Once I have a 10MHz reference I'd use that to run a hardware digital clock with 7-segment displays maybe down to the millisecond, just for fun (you'd need a high speed camera to see what time it is, but the act of reading the time that way totally defeats the purpose which I find amusing). Synchronising such a clock beyond NTP or GNSS becomes a whole exercise in itself. Realistically, GNSS is the best way to get accurate time. But buying a cheap GPSDO and plugging it in isn't very rewarding, nor do I learn anything useful.
>
> I was impressed by the ability of WSJT-x to run a frequency calibration using various sources. Using it, I found out that some of the local AM stations are well-disciplined and others are free-running (a couple were considerably off-frequency, 2.5ppm or so while my FT-897D's TCXO ended up being around 1ppm off).
>
> Cheers
>
> Geoff VK2WA
>
>
> On 13/3/25 20:24, Sebastien F4GRX via time-nuts wrote:
>> Hello,
>>
>> We will probably regret that one day.
>>
>> That's why I'm interested (as a mere amateur) by self contained
>> oscillators (with manual periodical recalibration while the
>> possibility lasts, and not just via gnss).
>>
>> Sebastien
>>
>>
>> On 13/03/2025 08:07, Poul-Henning Kamp via time-nuts wrote:
>>> --------
>>> Attila Kinali via time-nuts writes:
>>>
>>>
>>>> Does someone know what happened in the 90s regarding frequency jumps?
>>> GPS disciplining ?
>>>
>>> Almost nothing is free-wheeling any more.
>>>
>> _______________________________________________
>> time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe send
>> an email to time-nuts-leave@lists.febo.com
> _______________________________________________
> time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe send an email to time-nuts-leave@lists.febo.com
> _______________________________________________
> time-nuts mailing list -- time-nuts@lists.febo.com
> To unsubscribe send an email to time-nuts-leave@lists.febo.com
