[TangerineSDR] Tweaking rubidium

[Phil Erickson]

Hi Phil,

  It seems you are already a time-nut with that description :)

  I seem to recall that the difference between GPSDO internal loop
algorithms is the way that they adjust frequency/phase in the time frames
you're noticing (landing in the middle of the Allan Deviation curves,
between long term behavior and short term behavior dominated by the
oscillator quality).  Some of them are more gentle and some are more
abrupt.  John Ackermann N8UR could now opine a lot on that quality, and it
might bear on how you design the calibration scheme for the particular TCXO
in the RX888.

73
Phil W1PJE


On Tue, Jul 2, 2024 at 11:50 AM Phil Karn via TangerineSDR <
tangerinesdr at lists.tapr.org> wrote:

> After sitting all night, it's a phase change of -9 degrees in ~1000
> seconds, or a relative error of -2.7e-12. Not bad.
>
> Next step is to implement that software calibration scheme I mentioned,
> where a channel uses its software PLL to adjust the calibration on the
> RX888's own TCXO. Will be useful for those without hardware references
> or those who don't want to semi-permanently require the use of one in
> their RX888.
>
> I'm going to have to be careful lest I become a time nut.
>
> Phil
>
>
>
> --
> TangerineSDR mailing list
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-- 
----
Phil Erickson
phil.erickson at gmail.com
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