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

paul swed paulswedb at gmail.com
Sun Apr 29 03:04:29 UTC 2012


Other thing I have no clue to. What happens to photocells after X years.
I suspect they degrade also. Since thats the frontend of the rcvr that
would do quite a number.
Regards

On Sat, Apr 28, 2012 at 7:37 PM, Magnus Danielson <
magnus at rubidium.dyndns.org> wrote:

> Hi Ed,
>
>
> On 04/28/2012 08:43 PM, Ed Palmer wrote:
>
>> First, I'd like to thank Magnus, Joe, Paul, and Ed for taking the time
>> to provide answers, ideas, and challenges to my assumptions. It has all
>> been very helpful. I'm still working on it so I don't have a resolution
>> yet.
>>
>
> Happy to help, while not tossing you necessarily the solution, we have to
> read up and we all learn in the process... which was kind of the point with
> the exercise.
>
>
>  Second, pictures. If anyone is interested, check out
>> http://s701.photobucket.com/**albums/ww18/edpalmer42/Tracor%**20304-B/<http://s701.photobucket.com/albums/ww18/edpalmer42/Tracor%20304-B/>.
>>
>
> Nice photos. Thanks. GAS building up.
>
>
>  Third, I'd like to build an extender board, but I can't find the
>> connectors. The contacts are called Varicon and are used both on circuit
>> boards and in connectors. The connector version is available, but I
>> can't find the board version. The last picture in the above gallery
>> shows a close-up of the connectors. They were available in regular and
>> mini versions. I need the regular ones that stand about 4.3 mm high. The
>> minis are about 3.5 mm high and won't mate with the regular ones. New
>> ones could be loose or spaced out on a plastic strip to make
>> installation easier.
>>
>> Fourth, I'm currently working on the cavity tuning. Does anyone know of
>> a document or research paper that discusses cavity sizes for Rb
>> standards - preferably with equations? I found this document:
>>
>> http://www.alcatel-lucent.com/**bstj/vol25-1946/articles/**
>> bstj25-3-408.pdf<http://www.alcatel-lucent.com/bstj/vol25-1946/articles/bstj25-3-408.pdf>
>>
>
> Good article. Thanks for the reference.
>
>
>  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.
>
> 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<http://dspace.thapar.edu:8080/dspace/bitstream/10266/968/1/Satyendr_Thesis.pdf>
>
> Cheers,
> Magnus
>
>
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