[time-nuts] FE-5680A Voltage tolerance

Ed Palmer ed_palmer at sasktel.net
Thu Jan 19 21:43:11 EST 2012

Speaking of aging, can anyone explain FEI's spec for aging on the 
5680A?  2e-11 per DAY?  Seriously?  Everyone else specs their Rb 
standards in the Xe-11 range per MONTH.  When I first saw it, I thought 
it was just a typo, but it's in multiple documents and web pages and 
it's been there for years.


On 1/19/2012 7:35 PM, EWKehren at aol.com wrote:
> As soon as my next unit comes in I will run some controlled tests. This one
>   refuses to show aging with week 9 up in two days. I will use it for other
> tests  before I take it appart.
> Bert
> In a message dated 1/19/2012 8:18:10 P.M. Eastern Standard Time,
> ed_palmer at sasktel.net writes:
> I would  expect the RF circuitry to handle a lower voltage without too
> much  trouble.  However, a lower input voltage means it will take longer
> for the ovens to come up to temperature.  Until they stabilize, a  lock
> probably won't happen.
> Once the unit has warmed up and locked,  how low can you go and still
> maintain lock?  As you drop the voltage,  the ovens will run closer to
> full on.  Once you reach the point where  one or more of the ovens are
> full on, further voltage reduction will  quickly cause issues.
> Ed
> On 1/19/2012 5:45 PM, gonzo .  wrote:
>> Experiment for the day.
>> I thought I'd follow Dons quote  and see how tolerant my unit is.
>> My benchmark is at 15.5V it locks in  about 3min.
>> I backed off the supply to 10.8V and the lock time (from  cold) is 8min.
>> I thought this was interesting given several  people report they are unable to get a lock when running lower  voltage.
>>   ian

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