Empathy List Archives

SW

Skip Withrow

Thu, Aug 31, 2023 5:57 PM

Hello time-nuts,
Five or six years ago I cut open one of the original HP cesium beam tubes
and posted some pictures. I presume they are floating around the net
somewhere still.

So, I have repeated the exercise with one of the newer (smaller) tubes, and
thought I would share the results. Attached are a half dozen photos,
several are annotated to get the lay of the land. I have higher resolution
non-annotated versions if anyone has a desire.

Some observations are:

There are four nice holes that can be used to mount the cut open unit
above a base using screws or standoffs. And from the scratches appears to
be how HP mounted the innards during assembly.
After these pictures were taken I cut a window in the mu metal shield
hoping to expose the microwave waveguide. What did I find - another mu
metal shield, argh. It's too tight to get my Dremel tool in there to cut
through the second one.

I have four (4) of these tubes and three (3) of the older style tubes that
are excess to my needs. If anyone wants one I'm willing to ship, but they
are heavy (about 20 pounds). The leads are cut off these tubes - they are
dead. I would anticipate shipping would be about $35-$40 to the lower 48.
Please contact me off-list if interested.

Regards,
Skip Withrow

Hello time-nuts, Five or six years ago I cut open one of the original HP cesium beam tubes and posted some pictures. I presume they are floating around the net somewhere still. So, I have repeated the exercise with one of the newer (smaller) tubes, and thought I would share the results. Attached are a half dozen photos, several are annotated to get the lay of the land. I have higher resolution non-annotated versions if anyone has a desire. Some observations are: 1. There are four nice holes that can be used to mount the cut open unit above a base using screws or standoffs. And from the scratches appears to be how HP mounted the innards during assembly. 2. After these pictures were taken I cut a window in the mu metal shield hoping to expose the microwave waveguide. What did I find - another mu metal shield, argh. It's too tight to get my Dremel tool in there to cut through the second one. I have four (4) of these tubes and three (3) of the older style tubes that are excess to my needs. If anyone wants one I'm willing to ship, but they are heavy (about 20 pounds). The leads are cut off these tubes - they are dead. I would anticipate shipping would be about $35-$40 to the lower 48. Please contact me off-list if interested. Regards, Skip Withrow

TV

Tom Van Baak

Thu, Aug 31, 2023 8:01 PM

Five or six years ago I cut open one of the original HP cesium beam tubes
and posted some pictures. I presume they are floating around the net
somewhere still.

Yes, there are at least 3 copies: your original posting, the RDR
website, and your user directory on leapsecond:

https://febo.com/pipermail/time-nuts_lists.febo.com/2016-October/083806.html
http://www.rdrelectronics.com/skip/CS-tube/
http://leapsecond.com/u/skip/CBT-2016/

There are 2 copies of your new photos:

https://febo.com/pipermail/time-nuts_lists.febo.com/2023-August/108284.html
http://leapsecond.com/u/skip/CBT-2023/

You did a really nice job with the cut-away. Do you want to describe the
tools & technique that you used? Many of us have dead CBT at home and
these "tear down" projects are always fascinating but it seems like a
lot of messy work.

Here are photos of some cesium tubes on display at the hp factory in
Santa Clara (2005):

http://leapsecond.com/pages/cesium-tube/

For scale, here's a modern tube (5071A) next to the first commercial
cesium beam tube (Atomichron, late 1950's):

http://leapsecond.com/pages/cesium-tube/CBT-Atomichron-5071A-IMG_6441.jpg

/tvb

> Five or six years ago I cut open one of the original HP cesium beam tubes > and posted some pictures. I presume they are floating around the net > somewhere still. Yes, there are at least 3 copies: your original posting, the RDR website, and your user directory on leapsecond: https://febo.com/pipermail/time-nuts_lists.febo.com/2016-October/083806.html http://www.rdrelectronics.com/skip/CS-tube/ http://leapsecond.com/u/skip/CBT-2016/ There are 2 copies of your new photos: https://febo.com/pipermail/time-nuts_lists.febo.com/2023-August/108284.html http://leapsecond.com/u/skip/CBT-2023/ You did a really nice job with the cut-away. Do you want to describe the tools & technique that you used? Many of us have dead CBT at home and these "tear down" projects are always fascinating but it seems like a lot of messy work. ---- Here are photos of some cesium tubes on display at the hp factory in Santa Clara (2005): http://leapsecond.com/pages/cesium-tube/ For scale, here's a modern tube (5071A) next to the first commercial cesium beam tube (Atomichron, late 1950's): http://leapsecond.com/pages/cesium-tube/CBT-Atomichron-5071A-IMG_6441.jpg /tvb

MD

Magnus Danielson

Thu, Aug 31, 2023 8:22 PM

Hi Skip!

Thank you for a very nice set of photos! You already made my curiosity
somewhat satisfied.

It would be nice to have the next step of the "blow up sketch" with
photos of the various components. Not saying that it is your job to do
it, but to fully satisfy curiosity and do more of the show and tell.

I've contemplated doing something like this, but not got around to do it.

Cheers,
Magnus

On 2023-08-31 19:57, Skip Withrow via time-nuts wrote:

Hello time-nuts,
Five or six years ago I cut open one of the original HP cesium beam tubes
and posted some pictures. I presume they are floating around the net
somewhere still.

So, I have repeated the exercise with one of the newer (smaller) tubes, and
thought I would share the results. Attached are a half dozen photos,
several are annotated to get the lay of the land. I have higher resolution
non-annotated versions if anyone has a desire.

Some observations are:

There are four nice holes that can be used to mount the cut open unit
above a base using screws or standoffs. And from the scratches appears to
be how HP mounted the innards during assembly.
After these pictures were taken I cut a window in the mu metal shield
hoping to expose the microwave waveguide. What did I find - another mu
metal shield, argh. It's too tight to get my Dremel tool in there to cut
through the second one.

I have four (4) of these tubes and three (3) of the older style tubes that
are excess to my needs. If anyone wants one I'm willing to ship, but they
are heavy (about 20 pounds). The leads are cut off these tubes - they are
dead. I would anticipate shipping would be about $35-$40 to the lower 48.
Please contact me off-list if interested.

Regards,
Skip Withrow

time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe send an email to time-nuts-leave@lists.febo.com

Hi Skip! Thank you for a very nice set of photos! You already made my curiosity somewhat satisfied. It would be nice to have the next step of the "blow up sketch" with photos of the various components. Not saying that it is your job to do it, but to fully satisfy curiosity and do more of the show and tell. I've contemplated doing something like this, but not got around to do it. Cheers, Magnus On 2023-08-31 19:57, Skip Withrow via time-nuts wrote: > Hello time-nuts, > Five or six years ago I cut open one of the original HP cesium beam tubes > and posted some pictures. I presume they are floating around the net > somewhere still. > > So, I have repeated the exercise with one of the newer (smaller) tubes, and > thought I would share the results. Attached are a half dozen photos, > several are annotated to get the lay of the land. I have higher resolution > non-annotated versions if anyone has a desire. > > Some observations are: > 1. There are four nice holes that can be used to mount the cut open unit > above a base using screws or standoffs. And from the scratches appears to > be how HP mounted the innards during assembly. > 2. After these pictures were taken I cut a window in the mu metal shield > hoping to expose the microwave waveguide. What did I find - another mu > metal shield, argh. It's too tight to get my Dremel tool in there to cut > through the second one. > > I have four (4) of these tubes and three (3) of the older style tubes that > are excess to my needs. If anyone wants one I'm willing to ship, but they > are heavy (about 20 pounds). The leads are cut off these tubes - they are > dead. I would anticipate shipping would be about $35-$40 to the lower 48. > Please contact me off-list if interested. > > Regards, > Skip Withrow > > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe send an email to time-nuts-leave@lists.febo.com

PS

paul swed

Thu, Aug 31, 2023 8:35 PM

Skip,
I remember your other pictures and do have them downloaded. Now some nice
new high resolution pix.
What I don't understand is the ION pump. I see the HV lead attaching to a
silver circular piece of metal. I sort of thought the ION pump was a getter
electrode. Obviously its more complicated and may depend on the A magnet in
some way.
Regards
Paul.
WB8TSL

On Thu, Aug 31, 2023 at 3:23 PM Skip Withrow via time-nuts <
time-nuts@lists.febo.com> wrote:

Hello time-nuts,
Five or six years ago I cut open one of the original HP cesium beam tubes
and posted some pictures. I presume they are floating around the net
somewhere still.

So, I have repeated the exercise with one of the newer (smaller) tubes, and
thought I would share the results. Attached are a half dozen photos,
several are annotated to get the lay of the land. I have higher resolution
non-annotated versions if anyone has a desire.

Some observations are:

There are four nice holes that can be used to mount the cut open unit
above a base using screws or standoffs. And from the scratches appears to
be how HP mounted the innards during assembly.
After these pictures were taken I cut a window in the mu metal shield
hoping to expose the microwave waveguide. What did I find - another mu
metal shield, argh. It's too tight to get my Dremel tool in there to cut
through the second one.

I have four (4) of these tubes and three (3) of the older style tubes that
are excess to my needs. If anyone wants one I'm willing to ship, but they
are heavy (about 20 pounds). The leads are cut off these tubes - they are
dead. I would anticipate shipping would be about $35-$40 to the lower 48.
Please contact me off-list if interested.

Regards,
Skip Withrow

time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe send an email to time-nuts-leave@lists.febo.com

Skip, I remember your other pictures and do have them downloaded. Now some nice new high resolution pix. What I don't understand is the ION pump. I see the HV lead attaching to a silver circular piece of metal. I sort of thought the ION pump was a getter electrode. Obviously its more complicated and may depend on the A magnet in some way. Regards Paul. WB8TSL On Thu, Aug 31, 2023 at 3:23 PM Skip Withrow via time-nuts < time-nuts@lists.febo.com> wrote: > Hello time-nuts, > Five or six years ago I cut open one of the original HP cesium beam tubes > and posted some pictures. I presume they are floating around the net > somewhere still. > > So, I have repeated the exercise with one of the newer (smaller) tubes, and > thought I would share the results. Attached are a half dozen photos, > several are annotated to get the lay of the land. I have higher resolution > non-annotated versions if anyone has a desire. > > Some observations are: > 1. There are four nice holes that can be used to mount the cut open unit > above a base using screws or standoffs. And from the scratches appears to > be how HP mounted the innards during assembly. > 2. After these pictures were taken I cut a window in the mu metal shield > hoping to expose the microwave waveguide. What did I find - another mu > metal shield, argh. It's too tight to get my Dremel tool in there to cut > through the second one. > > I have four (4) of these tubes and three (3) of the older style tubes that > are excess to my needs. If anyone wants one I'm willing to ship, but they > are heavy (about 20 pounds). The leads are cut off these tubes - they are > dead. I would anticipate shipping would be about $35-$40 to the lower 48. > Please contact me off-list if interested. > > Regards, > Skip Withrow > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe send an email to time-nuts-leave@lists.febo.com

time-nuts@lists.febo.com

So what's inside that Cs beam tube anyway?