[time-nuts] Re: Video of early Cesium clock development

[Tom Van Baak]

Jerry, thanks for posting that National Co Atomichron video link. And, 
Tim, thanks for posting the Smithsonian link.

---

The first *laboratory* cesium standard was made by Louis Essen. Much has 
been written about this. My own pilgrimage:

 Â  http://leapsecond.com/museum/essen/

The first *commercial* cesium standard was the Atomichron by the 
National Company. A short article here:

https://www.rfcafe.com/references/radio-news/atomichron-worlds-most-accurate-clock-january-1957-radio-television-news.htm

About 50 of these early cesium clocks were made. Several are known to 
still exist: one owned by the Smithsonian as Tim noted, one at the NAWCC 
museum, and at least two in private hands. Some photos of the one I 
found on eBay are here:

 Â  http://leapsecond.com/museum/nc2001/

To get a feel for the size of this beast, here is a comparison of the 
Atomichron beam tube with a 5060 / 5061 / 5071 beam tube:

 Â  http://leapsecond.com/museum/nc2001/IMG_6441-600x800.jpg

This photo is also attached (an excuse to test normal vs. digest mode 
photo handling). It's also featured here:

 Â  https://insidegnss.com/time-is-relative-position-absolute/

---

If you are old enough to remember the vacuum tube and "atoms for peace" 
era you will appreciate the brilliant name choice for "Atomichron". A 
detailed Atomichron article by Paul Forman:

https://ieee-uffc.org/about-us/history/uffc-s-history/atomichron/

One interesting anecdote in the ieee article is Jerrold Zacharias and 
his "Fallotron", the original concept for what we now know as a Cesium 
fountain. And to wrap up this history of atomic clocks posting, here's a 
classic, including cesium and H-maser photos, by Norman Ramsey:

 Â  https://nvlpubs.nist.gov/nistpubs/jres/088/jresv88n5p301_A1b.pdf

/tvb


On 4/12/2021 11:45 AM, Tim Shoppa wrote:
> For those interested in the National Company’s cesium clocks, you can
> google “Atomichron” (their brand name) or check out this Smithsonian
> archive: https://sova.si.edu/record/NMAH.AC.0547
> <https://sova.si.edu/record/NMAH.AC.0547>
>
> Tim N3QE
>
> On Monday, April 12, 2021, Jerry Steinback via time-nuts <
> time-nuts at lists.febo.com> wrote:
>
>> While munging around on Youtube, this short filmstrip popped up; it
>> appears to be one of those short fillers for movie theater audiences. The
>> first four minutes might be interesting to members of the group.
>>      https://www.youtube.com/watch?v=NoDElB6HMCg
>>
>> Compared to any Cesium standard in the past couple(?) of decades it
>> reminds me of the old Stan Freberg commercial for Contadina tomato paste:
>> ''Who put eight great tomatoes in that little bitty can?''
>> Jerry
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