[time-nuts] Antique Rb Standard - Thanks, Pictures, Parts Request, Question

Magnus Danielson magnus at rubidium.dyndns.org
Sun Apr 29 23:21:24 UTC 2012


Hi Ed,

On 04/29/2012 05:46 PM, Ed Palmer wrote:
> Hi Magnus,
>
>>> Second, pictures. If anyone is interested, check out
>>> http://s701.photobucket.com/albums/ww18/edpalmer42/Tracor%20304-B/ .
>>
>> Nice photos. Thanks. GAS building up.
>
> What does GAS mean?

Gear Acquisition Syndrome.

GAS is a diagnose which I think no time-nut would admit to. ;-)

>>> that talks about cavities in general, but the calculations don't work.
>>> I'm guessing that the Rb cell is changing the resonant frequency of the
>>> cavity.
>>
>> The glass pulls the cavity resonance somewhat, yes. A TE111 resonance
>> mode is typically used, allowing light to enter and leave at the ends
>> of the cylinder.
>>
>> TE011 was used before, but it much larger.
>>
>> Todays modern cells use a "loaded" cell (dielectrum added) to move the
>> resonance frequency down, which allows much smaller physical cells.
>
> This unit is TE011 No dielectric, plain brass - not silver-plated, 2.495
> inch diameter @ room temperature, length tunable from ~0.9 to 1.07 inches.

Not surprising, and actually I think I've read that during the day.

>> W.J.Riley "Rubidium Frequency Standard Primer" is a good
>> starting-point, but following the references should help.
>>
>> I think just searching for "TE111 mode rubidium" cranks out a few
>> interesting things, such as:
>>
>> http://dspace.thapar.edu:8080/dspace/bitstream/10266/968/1/Satyendr_Thesis.pdf
>>
>>
> Thanks for that link. I have been searching, but it's like panning for
> gold - lots of sand and dirt and a very few nuggets of gold.

Indeed. I have a few more hints on where it can be worth panning, as I 
have gathered a few books on the subject.

Reading Riley's book (as I mentioned above) today has given much more 
body to the subject. Learning things quickly. While his book isn't heavy 
on the deep stuff, he summarize it so you get an overview and then gives 
several hundreds of references.

Cheers,
Magnus




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