[time-nuts] low-g OCXO GPSDO

[John Miles]

> From: "Matt Ettus" <boyscout at gmail.com>
> Subject: Re: [time-nuts] low-g OCXO GPSDO
> Date: Thu, 5 Jun 2008 10:25:43 -0700
> Message-ID: <ad9f78230806051025i22149aeci191f71bb7f7f602 at mail.gmail.com>
>
> > > A "normal" OCXO would drift significantly when being turned
> around in any
> > > direction.
> >
> > I've actually been wondering about what physical mechanism that causes
> > this.  I could understand how it could cause a phase shift, but I
> > can't envision the cause of frequency shift.  Does anyone know?
>
> Anything that deforms the actual crystal will slightly change the
> acoustical
> waveequation and thus the frequency. Crystals also deforms due to
> electrostatics, which have been used by NIST for finegrained
> phase modulation.

I wonder what would happen to g-sensitivity if you ran the crystal with a DC
bias across it.  If you could pre-compress the crystal electrostatically,
maybe it would become less sensitive to orientation.

-- john, KE5FX