You mean I can't just drill a hole in,  wash out the old cesium with some tap water ;-),  toss in some new cesium, suck out the air,  bung a cork in the hole, and call it a day?  Drat! foiled again...

Welllll you know we all love to talk of details. But crazy stuff happens
when you try.
As mentioned you would dirty everything up. But waiting a year to de-gas
etc well what the heck.
I was looking at the pix of the ampule nothing is clear to me at least as
to how you even would insert some new C's. Just curiosity.

Other thing you can actually buy the cesium stuff online and it wasn't that
expensive. Granted quality?????????????????????????????
Regards
Paul
WB8TSL

On Tue, Nov 1, 2016 at 11:38 PM, Mark Sims holrum@hotmail.com wrote:

This has probably been covered here before, but, at least going
to the 5071A, now 25 years ago!, all CBT's, whether high
performance or not, have the same amount of cesium inside.
This means that the standard performance (never call it
"low" performance) CBT has enough cesium to last 30 years!
Thus for those tubes, we can rule out cesium replenishment
even if it were possible.

Rick

On 11/1/2016 8:38 PM, Mark Sims wrote:

Oh yes and guess which tubes we find? The 40 year olds at ham prices. :-)
At least thats what I have.
Like your comment as so far what I have learned is that seems like other
things going on.
I sort of believe its C pollution of things like the ionizer and even the
photo tube elements over time. Its a curiosity without much of a way to
prove it.

Regards
Paul
WB8TSL

On Wed, Nov 2, 2016 at 10:53 AM, Richard (Rick) Karlquist <
richard@karlquist.com> wrote:

Just throwing this out: would it be possible recover the cesium by heating
the tube but cooling it near where the reservior is?  This might cause the
cesium to migrate in that direction and some of it end up in the reservior?

Pete.

On 11/2/2016 11:38 AM, paul swed wrote:

I may be missing something (as I often do) but why not just buy some
cesium? About ten bucks a gram for high-purity metal in glass ampoules.

On Wednesday, November 2, 2016, Peter Reilley preilley_454@comcast.net
wrote:

--
If you gaze long into an abyss, your coffee will get cold.

William thats what I found also. Now you have to get it into the tube.
To the comment on heating. Thats sort of how Frankenstein works 5060 tube
in a 5061. I designed a DC oven controller and run the oven hotter.
I now speculate the reason they ran the ac oven was because DC interferes
as a magnetic field. The signal is noisy but locks always. This tube is so
weak that only through more amplification an external meter and magnifying
glass do I find beam peaks. But they are there. Talk about a pain to tune
for.
By the way to prove that theory I need to build a AC oven controller. Sort
of just haven't gotten there.
??? For really smart folks.
Frankenstein runs slightly fast and I can see this. If the Cesium is hotter
then the  specified temperature I suspect the lines slightly move.
Everything will lock but its not correct.
Is that a reasonable answer?
Thanks
Paul
WB8TSL

On Wed, Nov 2, 2016 at 12:04 PM, William H. Fite omniryx@gmail.com wrote:

Hi Rick,

That's consistent with what I've seen and heard as well. Most of the 5061B / 5071A on eBay with dead tubes are opt 001 (high-performance) tubes. The surplus units with standard performance tubes are more likely to power up and lock. And if they don't, it's probably something simple rather than a dead Cs tube.

I've also heard that the choice of high- vs std-performance is made after the tube is built. The difference would be in things like the oven temp and detector gain, both of which are controlled outside the tube. My first hint of this was in a paper by Carroll Alley...

You know the famous 1971 Hafele-Keating experiment with four 5061 cesium clocks flying around the world. Several years later, a more precise measurement was made by Carroll Alley using better clocks. What I read is that he got Len Cutler to hack the 5061A so that its beam current would be higher, thereby improving performance for the duration of the experiment. Same tube, just different operating parameters.

See page 3 of:
http://www.hp.com/hpinfo/abouthp/histnfacts/publications/measure/pdf/1977_04.pdf

For newcomers to the group, a good introduction to hp and flying clocks is here, along with copies of several HPJ articles:

http://www.hpmemoryproject.org/news/flying_clock/celebration_01.htm

/tvb

----- Original Message -----
From: "Richard (Rick) Karlquist" richard@karlquist.com
To: "Discussion of precise time and frequency measurement" time-nuts@febo.com
Sent: Wednesday, November 02, 2016 7:53 AM
Subject: Re: [time-nuts] So what’s inside that Cs Beam Tube anyway?

On Wed, 2 Nov 2016 12:04:41 -0400
"William H. Fite" omniryx@gmail.com wrote:

No, you aren't missing anything. That's what you actually would do
if you were in a undergrad lab and doing atomic spectroscopy experiments
in high vacuum. You use one of these ampoules, put them in the chamber,
evacuate, then break the ampoul to let the caesium out and tadaaaa! you
have lots of caesium vapor around to play with.

But with a beam tube you need to get the caesium into the oven assembly.
And that's the hard part. The build up of these ovens is rather simple:
You have a small cavity, in which the caesium is contained. to one side
you have small tubes, all parallel and with very small diameter that
act as a collimator (aka make the atoms that are comming out fly in one
direction only). Unless the oven assembly is made to be opened and refilled,
refilling through these tubes is basically impossible. In case you actually
have the equipment to open up, close again and evacuate a beam tube, you
probably also be able to build a new oven assembly and use that instead.

			Attila Kinali

--
Malek's Law:
Any simple idea will be worded in the most complicated way.

On 11/2/2016 10:23 AM, Tom Van Baak wrote:

Never heard that story.  You gotta love it:  a hot rod atomic clock.

Rick