[time-nuts] RC TIC linearity correction?

[Chris Albertson]

On Wed, Mar 26, 2014 at 8:41 AM, Bob Stewart <bob at evoria.net> wrote:

> Thanks Charles.  That makes sense, but at the expense of adding unwanted
> complexity.  As I've been moving the setpoint around this morning, I think
> I see a way to characterize what it's doing.  Maybe I can come up with a
> small correction table or formula that's good enough for my purposes.
>

Yes a lookup table would be easy.  But how to create the table?  I've been
thinking about a way to do self calibration.   The controller purposely
runs the DAC and of course the OCXO through some range and watches the
phase.  This gives you a rough DAC vs. Phase function.   Re-running the
calibration could make up for some component aging.   It would take some
time (hours) to wait for everything to warm up and then you'd have to move
the EFV voltage slowly



-- 

Chris Albertson
Redondo Beach, California