[time-nuts] How Rubidiums make their frequency (was RE: time-nuts Digest, Vol 21, Issue 22)

Christopher Hoover ch at murgatroid.com
Thu Apr 20 05:31:08 EDT 2006

Tom Clark wrote:

>   Christopher Hoover asked:

>> one issue remains:   i have to crank the magnetic field setting almost to
>> its high limit (9.91/10.00) to get 5 MHz out; lower settings give a
>> frequency that is too low.   i presume this is unusual.    
>> i have a rudimentary understanding of the rubidium oscillator physics, 
>> but i do not understand what would cause this.  can i buy a clue?

>   I don't know the Tracor, but I imagine it is like most of the other
>   Rubidiums in it's innards.

Hi Tom,

That's a good explanation, thank you.   I got that much already.  (While it
took some time for my phyiscs, chemistry and semiconductor physics studies
to kick back in, it all clicked last week.)   The Tracor, indeed, seems
fairly ordinary compared to the other Rb's I have, going by the test points
and the various labels inside.   There is the typical synthesizer section,
audio demodulation section for the photocell, etc.

So what I'm really wondering is this: is there a  wear mechanism or failure
mode in the physics package that might explain why I have to crank the mag
field almost to its high limit to get 5 MHz?  (This question presumes the
mag field control is working properly, and I cannot say for sure that it

-- Christopher.

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