Creating a D.I.Y Rubidium Atomic Clock
All great points by Rick and Magnus, and I would add that purchasing some dead rubidium standards to disassemble and reverse engineer would also be a great learning experience before attempting a ground up build. Good luck, please keep us Time-Nuts updated on your progress.
Cheers;
Tom Knox
SR Test and Measurement Engineer
Phoenix Research
4870 Meredith Way Apt 102
Boulder, Co 80303
Formerly of:
357 Fox Lane
Superior Co 80027
303-554-0307
actast@hotmail.com
"Peace is not the absence of violence, but the presence of Justice" Both MLK and Albert Einstein
From: Magnus Danielson via time-nuts time-nuts@lists.febo.com
Sent: Wednesday, June 7, 2023 6:11 AM
To: time-nuts@lists.febo.com time-nuts@lists.febo.com
Cc: Magnus Danielson magnus@rubidium.se
Subject: [time-nuts] Re: Creating a D.I.Y Rubidium Atomic Clock
Hi,
I agree with Rick and was about to make more or less the same comment.
The glas package is the hardest thing to do, and there is also a certain
magic to mix the buffer gas just the right way to frequency compensate
the wall shift. Already there comes the aspect of knowing what wallshift
you will get, so you need reasonable reproduceability in both the glass
and pressure and mix in gases. To put that in other words, I am not THAT
crazy, yet.
Next level is the cavity you put the glas-ware into. The Q of that
resonator is not irrelevant, so you want to handle that.
There is a certain magic to the temperatures of the rubidium lamp and
that of the rubidium filter. This has consequences on how the physical
package is built. Some of this can be avoided today by using diodeds,
and that may even open up for avoiding the tuned resonator, but brings
in it's own set of issues.
Achievable engineering challenges, but maybe hard to do as a hobbyist.
The remaining temperature controls, FLL-lock of oscillator, synthesis
have become more and more achieveable over the years. That has become
hobbyist achieveable for sure.
However, just attempting to study up on a subject like this forces you
to learn alot, so even if you do not do a single soldering, you can have
improved your knowledge.
I would consider recycle an existing physical package that works and
make modern electronics for it. That should be plenty of challenges and
quite achieveable.
Cheers,
Magnus
On 2023-06-07 02:26, Richard Karlquist via time-nuts wrote:
In a former life, I was on the design team of a mini rubidium standard
at Hewlett-Packard. We built some working prototypes before it was
cancelled. It was going to have the model number 10816. I was the RF
person, but I worked very closely with the other team members.
Remembering what we had to go through to make "glassware", it is
inconceivable that you could do that as a "home brew" project. And this
was the same HP facility that already made the 5065 rubidium standard.
The best you could hope to do is to start with a commercial "physics
package" as we called it, and make your own electronics for it. Reading
books about how rubidium standards work, etc is fine, but again, you
can't home brew the glassware.
Rick Karlquist
N6RK
On 2023-06-06 15:39, Tom Van Baak via time-nuts wrote:
Hi Leo,
That sounds like a fun project. Here are some extremely informative resources:
"Introduction to the Rubidium Frequency Standard"
by Michael Parker, 358 pages
http://www.leapsecond.com/u/parker/ParkerIntroRFS-PPCP.pdf
"Rubidium Frequency Standard Primer"
by Bill Riley, 163 pages
http://www.wriley.com/Rubidium%20Frequency%20Standard%20Primer%20102211.pdf
"Selection Criteria for Rubidium Frequency Standards"
by Bill Riley, 51 pages
http://www.wriley.com/Selection%20Criteria%20for%20Rubidium%20Frequency%20Standards.pdf
Also read service manuals for commercial Rb products. Didier's site has a nice collection. Search by product number (e.g., 5065a) or by title (e.g., rubidium):
http://www.ko4bb.com/getsimple/index.php?id=manuals
/tvb
On 6/6/2023 12:25 PM, Leo Ahluwalia via time-nuts wrote:
Hello, my name is Leo, and I was wondering about the feasibility of
creating a simple rubidium atomic clock at home, and good places to source
parts for this sort of project. I was also wondering what instruments and
specialized knowledge would be required depending on how pre-built the
parts are, for example, the prerequisite knowledge for creating PLL(s) for
both frequency division to provide an output and also to modulate the input
of the microwave oscillator. Any good resources or PDFs would be greatly
appreciated, as I am very new to frequency analysis and phase manipulation
in general. I was also hoping to keep the cost of the project soft-line
below 500$, though that would be assuming a decent level of precision and
already possessing basic equipment (oscilloscope, multimeter, etc...). Safety
is also a major concern, as I know while the intensity of the EM waves
involved is low, the power source may or may not be. This is all of course
assuming a basic design, where my assumption is that it will involve the
microwaves being shot at a rubidium vapor cell which is directed towards a
photodetector. This would then be connected up to the PLL and circuitry to
both provide a stable standard while also modulating the microwave
oscillator to offset any external environmental factors. I don't have a
clear vision of what would truly be the best design for both simplicity and
cost, though this is what I've found to be a common design in what I've
looked at online.
Thanks, Leo
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Speaking of existing commercial "physics packages", various iterations of the FE-5680 are available on ebay. I got one years ago and was disappointed. I can't imagine them having made so many if they thought it was a failure, so I guess my expectations were higher. Could someone(s) comment on the FE-5680 and how it could be made better? Is it just a matter of temperature control, or is their physics package just not up to time-nuts standards?
Bob
On Wednesday, June 7, 2023 at 04:50:28 AM CDT, Richard Karlquist via time-nuts <time-nuts@lists.febo.com> wrote:
In a former life, I was on the design team of a mini rubidium standard
at Hewlett-Packard. We built some working prototypes before it was
cancelled. It was going to have the model number 10816. I was the RF
person, but I worked very closely with the other team members.
Remembering what we had to go through to make "glassware", it is
inconceivable that you could do that as a "home brew" project. And this
was the same HP facility that already made the 5065 rubidium standard.
The best you could hope to do is to start with a commercial "physics
package" as we called it, and make your own electronics for it. Reading
books about how rubidium standards work, etc is fine, but again, you
can't home brew the glassware.
Rick Karlquist
N6RK
On 2023-06-06 15:39, Tom Van Baak via time-nuts wrote:
Hi Leo,
That sounds like a fun project. Here are some extremely informative resources:
"Introduction to the Rubidium Frequency Standard"
by Michael Parker, 358 pages
http://www.leapsecond.com/u/parker/ParkerIntroRFS-PPCP.pdf
"Rubidium Frequency Standard Primer"
by Bill Riley, 163 pages
http://www.wriley.com/Rubidium%20Frequency%20Standard%20Primer%20102211.pdf
"Selection Criteria for Rubidium Frequency Standards"
by Bill Riley, 51 pages
http://www.wriley.com/Selection%20Criteria%20for%20Rubidium%20Frequency%20Standards.pdf
Also read service manuals for commercial Rb products. Didier's site has a nice collection. Search by product number (e.g., 5065a) or by title (e.g., rubidium):
http://www.ko4bb.com/getsimple/index.php?id=manuals
/tvb
On 6/6/2023 12:25 PM, Leo Ahluwalia via time-nuts wrote:
Hello, my name is Leo, and I was wondering about the feasibility of
creating a simple rubidium atomic clock at home, and good places to source
parts for this sort of project. I was also wondering what instruments and
specialized knowledge would be required depending on how pre-built the
parts are, for example, the prerequisite knowledge for creating PLL(s) for
both frequency division to provide an output and also to modulate the input
of the microwave oscillator. Any good resources or PDFs would be greatly
appreciated, as I am very new to frequency analysis and phase manipulation
in general. I was also hoping to keep the cost of the project soft-line
below 500$, though that would be assuming a decent level of precision and
already possessing basic equipment (oscilloscope, multimeter, etc...). Safety
is also a major concern, as I know while the intensity of the EM waves
involved is low, the power source may or may not be. This is all of course
assuming a basic design, where my assumption is that it will involve the
microwaves being shot at a rubidium vapor cell which is directed towards a
photodetector. This would then be connected up to the PLL and circuitry to
both provide a stable standard while also modulating the microwave
oscillator to offset any external environmental factors. I don't have a
clear vision of what would truly be the best design for both simplicity and
cost, though this is what I've found to be a common design in what I've
looked at online.
Thanks, Leo
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe send an email to time-nuts-leave@lists.febo.com
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To unsubscribe send an email to time-nuts-leave@lists.febo.com
The Rb capsules are available on ebay, eg: 124012486501
the classblowing part is done?
On 2023-06-07 07:50, Richard (Rick) Karlquist via time-nuts wrote:
On 6/7/2023 5:03 AM, Stephen C. Menasian via time-nuts wrote:
- some pure Rb87
- a glass blowing setup (and some skill)
- A selection of inert gasses (at least including Ar)
- Light source (Rb discharge was used then with a circular polarizer;
At HP we had really skilled glass blowers, with specific experience in
making Rb glassware. We had to use an exotic grade of glass that was
only one step removed from fused quartz. It had a part number that I
don't remember. Very difficult to work with.
The Rb lamp (one of three pieces of glassware) is very tricky to work
with. We used a resonant coil driven at 95 MHz at several watts.
The trick is to "strike" the plasma and make the lamp light up;
you can at least see visible light when that happens. I spent a
lot of time fooling with it. We never got it to work as
well as the 5065 lamp.
BTW, one of the Rb isotopes is slightly radioactive. Might be
hard to get as a hobbyist due to regulations. The physicist I
sat next to had a tank of it illegally stored in his cubicle.
Rick
N6RK
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe send an email to time-nuts-leave@lists.febo.com
"It's always something."
Roseanne Rosannadanna
----------------------"
Dr. Don Latham AJ7LL
PO Box 404, Frenchtown, MT, 59834
VOX: 406-626-4304
Certainly interesting topic. Rb provides a safe approach. However, I am curious to know if anyone has explored the possibility of using other elements, specifically Indium?
.md
On 7 Jun 2023, at 20:37, djl via time-nuts time-nuts@lists.febo.com wrote:
The Rb capsules are available on ebay, eg: 124012486501
the classblowing part is done?
On 2023-06-07 07:50, Richard (Rick) Karlquist via time-nuts wrote:
On 6/7/2023 5:03 AM, Stephen C. Menasian via time-nuts wrote:
- some pure Rb87
- a glass blowing setup (and some skill)
- A selection of inert gasses (at least including Ar)
- Light source (Rb discharge was used then with a circular polarizer;
At HP we had really skilled glass blowers, with specific experience in
making Rb glassware. We had to use an exotic grade of glass that was
only one step removed from fused quartz. It had a part number that I
don't remember. Very difficult to work with.
The Rb lamp (one of three pieces of glassware) is very tricky to work
with. We used a resonant coil driven at 95 MHz at several watts.
The trick is to "strike" the plasma and make the lamp light up;
you can at least see visible light when that happens. I spent a
lot of time fooling with it. We never got it to work as
well as the 5065 lamp.
BTW, one of the Rb isotopes is slightly radioactive. Might be
hard to get as a hobbyist due to regulations. The physicist I
sat next to had a tank of it illegally stored in his cubicle.
Rick
N6RK
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe send an email to time-nuts-leave@lists.febo.com
"It's always something."
Roseanne Rosannadanna
----------------------"
Dr. Don Latham AJ7LL
PO Box 404, Frenchtown, MT, 59834
VOX: 406-626-4304
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe send an email to time-nuts-leave@lists.febo.com
I would suspect that indium is not suitable. The easiest elements to pump
optically are the alkali metals, due to their strong D lines which allow
the ground state atoms to absorb the appropriate radiation strongly,
thus, enabling the optical pumping effect.
On Wed, 7 Jun 2023 22:37:42
+0200 Marek Doršic via time-nuts time-nuts@lists.febo.com wrote:
Certainly interesting topic. Rb provides a safe approach. However, I am
curious to know if anyone has explored the possibility of using other
elements, specifically Indium?
.md
On 7 Jun 2023, at 20:37, djl via time-nuts time-nuts@lists.febo.com
wrote:The Rb capsules are available on ebay, eg: 124012486501
the classblowing part is done?On 2023-06-07 07:50, Richard (Rick) Karlquist via time-nuts wrote:
On 6/7/2023 5:03 AM, Stephen C. Menasian via time-nuts wrote:
- some pure Rb87
- a glass blowing setup (and some skill)
- A selection of inert gasses (at least including Ar)
- Light source (Rb discharge was used then with a circular
polarizer;
At HP we had really skilled glass blowers, with specific experience
in making Rb glassware. We had to use an exotic grade of glass that
was only one step removed from fused quartz. It had a part number
that I don't remember. Very difficult to work with.
The Rb lamp (one of three pieces of glassware) is very tricky to work
with. We used a resonant coil driven at 95 MHz at several watts.
The trick is to "strike" the plasma and make the lamp light up;
you can at least see visible light when that happens. I spent a
lot of time fooling with it. We never got it to work as
well as the 5065 lamp.
BTW, one of the Rb isotopes is slightly radioactive. Might be
hard to get as a hobbyist due to regulations. The physicist I
sat next to had a tank of it illegally stored in his cubicle.
Rick
N6RK
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe send an email to time-nuts-leave@lists.febo.com
"It's always something."
Roseanne Rosannadanna
----------------------"
Dr. Don Latham AJ7LL
PO Box 404, Frenchtown, MT, 59834
VOX: 406-626-4304
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe send an email to time-nuts-leave@lists.febo.com
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To unsubscribe send an email to time-nuts-leave@lists.febo.com
My understanding is that the Rb85 and Rb87 isotopes happen to
accidentally be correct to make the optical filter cell work correctly.
I don't believe you can do this with any other atom. It's different
from primary atomic standards that just excite the hyperfine quantum
transition. In that case, you can debate about which atom or ion to
use.
Rick Karlquist
N6RK
On 2023-06-07 13:37, Marek Doršic via time-nuts wrote:
On 7 Jun 2023, at 20:37, djl via time-nuts time-nuts@lists.febo.com wrote:
Certainly interesting topic. Rb provides a safe approach. However, I am curious to know if anyone has explored the possibility of using other elements, specifically Indium?.md
That just leaves the Rubidium lamp.
An ECDL (external cavity diode laser) locked to the appropriate Rubidium transition is much easier to build. There are several ECDL designs in the literature. Mostly these are Littrow designs. A Cateye resonator design is another option. All the components required are readily availble.
VCSEL's should be avoided as those without polarisation mode stabilisation gratings on the output face randomly mode hop between a pair or orthogonally polarised modes.
A well designed but relatively simple ECDL can have a much narrower line width than a typical DFB laser.
Bruce
On 08/06/2023 06:37 NZST djl via time-nuts time-nuts@lists.febo.com wrote:
The Rb capsules are available on ebay, eg: 124012486501
the classblowing part is done?
On 2023-06-07 07:50, Richard (Rick) Karlquist via time-nuts wrote:
On 6/7/2023 5:03 AM, Stephen C. Menasian via time-nuts wrote:
- some pure Rb87
- a glass blowing setup (and some skill)
- A selection of inert gasses (at least including Ar)
- Light source (Rb discharge was used then with a circular polarizer;
At HP we had really skilled glass blowers, with specific experience in
making Rb glassware. We had to use an exotic grade of glass that was
only one step removed from fused quartz. It had a part number that I
don't remember. Very difficult to work with.The Rb lamp (one of three pieces of glassware) is very tricky to work
with. We used a resonant coil driven at 95 MHz at several watts.
The trick is to "strike" the plasma and make the lamp light up;
you can at least see visible light when that happens. I spent a
lot of time fooling with it. We never got it to work as
well as the 5065 lamp.BTW, one of the Rb isotopes is slightly radioactive. Might be
hard to get as a hobbyist due to regulations. The physicist I
sat next to had a tank of it illegally stored in his cubicle.Rick
N6RK
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe send an email to time-nuts-leave@lists.febo.com
"It's always something."
Roseanne Rosannadanna
----------------------"
Dr. Don Latham AJ7LL
PO Box 404, Frenchtown, MT, 59834
VOX: 406-626-4304
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe send an email to time-nuts-leave@lists.febo.com
At least one implementation of rubidium clocks I've seen use a lamp, filter and resonance cell.
The filter had rubidium 85, the lamp and resonance cell had rubidium 87 or possibly a natural isotopic mix, likely with the lamp being natural rubidium isotopic abundance.
I suspect the higher quality ones had resonance cells with isotopically enriched rubidium 87.
Increased signal to noise ratio would allow lower lamp power, and potentially both lower light shift, and longer lifetimes on components.
From: Stephen C. Menasian via time-nuts time-nuts@lists.febo.com
Sent: Wednesday, June 7, 2023 4:03:24 PM
To: Discussion of precise time and frequency measurement time-nuts@lists.febo.com
Cc: Stephen C. Menasian menasian@ptd.net
Subject: [time-nuts] Re: Creating a D.I.Y Rubidium Atomic Clock
I would suspect that indium is not suitable. The easiest elements to pump
optically are the alkali metals, due to their strong D lines which allow
the ground state atoms to absorb the appropriate radiation strongly,
thus, enabling the optical pumping effect.
On Wed, 7 Jun 2023 22:37:42
+0200 Marek Doršic via time-nuts time-nuts@lists.febo.com wrote:
Certainly interesting topic. Rb provides a safe approach. However, I am
curious to know if anyone has explored the possibility of using other
elements, specifically Indium?
.md
On 7 Jun 2023, at 20:37, djl via time-nuts time-nuts@lists.febo.com
wrote:
The Rb capsules are available on ebay, eg: 124012486501
the classblowing part is done?
On 2023-06-07 07:50, Richard (Rick) Karlquist via time-nuts wrote:
On 6/7/2023 5:03 AM, Stephen C. Menasian via time-nuts wrote:
- some pure Rb87
- a glass blowing setup (and some skill)
- A selection of inert gasses (at least including Ar)
- Light source (Rb discharge was used then with a circular
polarizer;
At HP we had really skilled glass blowers, with specific experience
in making Rb glassware. We had to use an exotic grade of glass that
was only one step removed from fused quartz. It had a part number
that I don't remember. Very difficult to work with.
The Rb lamp (one of three pieces of glassware) is very tricky to work
with. We used a resonant coil driven at 95 MHz at several watts.
The trick is to "strike" the plasma and make the lamp light up;
you can at least see visible light when that happens. I spent a
lot of time fooling with it. We never got it to work as
well as the 5065 lamp.
BTW, one of the Rb isotopes is slightly radioactive. Might be
hard to get as a hobbyist due to regulations. The physicist I
sat next to had a tank of it illegally stored in his cubicle.
Rick
N6RK
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe send an email to time-nuts-leave@lists.febo.com
"It's always something."
Roseanne Rosannadanna
----------------------"
Dr. Don Latham AJ7LL
PO Box 404, Frenchtown, MT, 59834
VOX: 406-626-4304
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
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To unsubscribe send an email to time-nuts-leave@lists.febo.com
I appreciate all of the help so far, and assuming the procurement of a
rubidium vapour cell and rubidium lamp (and of course all the other
components), I was wondering how exactly the optical pumping setup should
be achieved (to make sure all the components are "hooked up" so to speak),
and whether there was already a standard way of achieving it along with the
installation of the magnetic shielding?
- Leo
On Wed, Jun 7, 2023 at 6:27 PM Bruce Griffiths via time-nuts <
time-nuts@lists.febo.com> wrote:
That just leaves the Rubidium lamp.
An ECDL (external cavity diode laser) locked to the appropriate Rubidium
transition is much easier to build. There are several ECDL designs in the
literature. Mostly these are Littrow designs. A Cateye resonator design is
another option. All the components required are readily availble.
VCSEL's should be avoided as those without polarisation mode stabilisation
gratings on the output face randomly mode hop between a pair or
orthogonally polarised modes.
A well designed but relatively simple ECDL can have a much narrower line
width than a typical DFB laser.
Bruce
On 08/06/2023 06:37 NZST djl via time-nuts time-nuts@lists.febo.com
wrote:
The Rb capsules are available on ebay, eg: 124012486501
the classblowing part is done?
On 2023-06-07 07:50, Richard (Rick) Karlquist via time-nuts wrote:
On 6/7/2023 5:03 AM, Stephen C. Menasian via time-nuts wrote:
- some pure Rb87
- a glass blowing setup (and some skill)
- A selection of inert gasses (at least including Ar)
- Light source (Rb discharge was used then with a circular polarizer;
At HP we had really skilled glass blowers, with specific experience in
making Rb glassware. We had to use an exotic grade of glass that was
only one step removed from fused quartz. It had a part number that I
don't remember. Very difficult to work with.
The Rb lamp (one of three pieces of glassware) is very tricky to work
with. We used a resonant coil driven at 95 MHz at several watts.
The trick is to "strike" the plasma and make the lamp light up;
you can at least see visible light when that happens. I spent a
lot of time fooling with it. We never got it to work as
well as the 5065 lamp.
BTW, one of the Rb isotopes is slightly radioactive. Might be
hard to get as a hobbyist due to regulations. The physicist I
sat next to had a tank of it illegally stored in his cubicle.
Rick
N6RK
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe send an email to time-nuts-leave@lists.febo.com
"It's always something."
Roseanne Rosannadanna
----------------------"
Dr. Don Latham AJ7LL
PO Box 404, Frenchtown, MT, 59834
VOX: 406-626-4304
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
This might be of interest:
https://apps.dtic.mil/sti/pdfs/ADA627237.pdf
From: Ed Marciniak ed@nb0m.org
Sent: Wednesday, June 7, 2023 5:37:16 PM
To: Discussion of precise time and frequency measurement time-nuts@lists.febo.com
Cc: Stephen C. Menasian menasian@ptd.net
Subject: Re: [time-nuts] Re: Creating a D.I.Y Rubidium Atomic Clock
At least one implementation of rubidium clocks I've seen use a lamp, filter and resonance cell.
The filter had rubidium 85, the lamp and resonance cell had rubidium 87 or possibly a natural isotopic mix, likely with the lamp being natural rubidium isotopic abundance.
I suspect the higher quality ones had resonance cells with isotopically enriched rubidium 87.
Increased signal to noise ratio would allow lower lamp power, and potentially both lower light shift, and longer lifetimes on components.
From: Stephen C. Menasian via time-nuts time-nuts@lists.febo.com
Sent: Wednesday, June 7, 2023 4:03:24 PM
To: Discussion of precise time and frequency measurement time-nuts@lists.febo.com
Cc: Stephen C. Menasian menasian@ptd.net
Subject: [time-nuts] Re: Creating a D.I.Y Rubidium Atomic Clock
I would suspect that indium is not suitable. The easiest elements to pump
optically are the alkali metals, due to their strong D lines which allow
the ground state atoms to absorb the appropriate radiation strongly,
thus, enabling the optical pumping effect.
On Wed, 7 Jun 2023 22:37:42
+0200 Marek Doršic via time-nuts time-nuts@lists.febo.com wrote:
Certainly interesting topic. Rb provides a safe approach. However, I am
curious to know if anyone has explored the possibility of using other
elements, specifically Indium?
.md
On 7 Jun 2023, at 20:37, djl via time-nuts time-nuts@lists.febo.com
wrote:
The Rb capsules are available on ebay, eg: 124012486501
the classblowing part is done?
On 2023-06-07 07:50, Richard (Rick) Karlquist via time-nuts wrote:
On 6/7/2023 5:03 AM, Stephen C. Menasian via time-nuts wrote:
- some pure Rb87
- a glass blowing setup (and some skill)
- A selection of inert gasses (at least including Ar)
- Light source (Rb discharge was used then with a circular
polarizer;
At HP we had really skilled glass blowers, with specific experience
in making Rb glassware. We had to use an exotic grade of glass that
was only one step removed from fused quartz. It had a part number
that I don't remember. Very difficult to work with.
The Rb lamp (one of three pieces of glassware) is very tricky to work
with. We used a resonant coil driven at 95 MHz at several watts.
The trick is to "strike" the plasma and make the lamp light up;
you can at least see visible light when that happens. I spent a
lot of time fooling with it. We never got it to work as
well as the 5065 lamp.
BTW, one of the Rb isotopes is slightly radioactive. Might be
hard to get as a hobbyist due to regulations. The physicist I
sat next to had a tank of it illegally stored in his cubicle.
Rick
N6RK
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe send an email to time-nuts-leave@lists.febo.com
"It's always something."
Roseanne Rosannadanna
----------------------"
Dr. Don Latham AJ7LL
PO Box 404, Frenchtown, MT, 59834
VOX: 406-626-4304
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