[time-nuts] DC Voltage Ramp?
Tom Van Baak
tvb at leapsecond.com
Sun Sep 4 15:26:46 EDT 2005
> You need to come up with the ramp/parabolic which will compensate your
> oscillators linear frequency error and frequency drift and the only way to
> that properly is to compare it to something which is better. So, you need
> compare against a Cesium or GPS, and then calculate the parameters, and
Even if you compare to something better you seem
to imply that a given quartz oscillator has "parameters"
as if they were some fixed immutable value valid for
all times and scaleable up or down for any tau. This
is not the case.
Drift rate specifications can be made per day or month
or year. These are not specs of how the oscillator must
perform or will perform; they are often guaranteed limits
on how bad the oscillator will perform.
You can measure the actual daily drift rate by taking
a month of data and dividing by 30. But if you do this
my guess is you will be amazed how much the daily
drift rate varies from day to day, or hour to hour.
> redo this. In order to handle other perturbations such as random phase
> and result of mechanical chock, you need to do this on a regular basis.
> What you now have is a control-loop of some sort, wherein a PLL is really
> one perticular class.
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