[time-nuts] Re: What's the best HP OCXO for frequency counter reference?

[Jeremy Nichols]

OCXOs generally don’t require a lot of power. A small (portable size) UPS
can keep the OCXO powered up while on the move. With an appropriate
inverter, the UPS can be powered by a vehicle. Think “flying clock” of
years ago.



On Tue, Jun 28, 2022 at 3:59 PM Bob kb8tq via time-nuts <
time-nuts at lists.febo.com> wrote:

> Hi
>
>
> > On Jun 28, 2022, at 12:15 PM, Hal Murray via time-nuts <
> time-nuts at lists.febo.com> wrote:
> >
> >
> > Adrian Godwin said:
> >> If you use the ovened oscillator for temporary use away from the home
> GPSDO,
> >> how good will the oscillator be with those interruptions to power /
> >> temperature, and will it stabilise during the period you're using it
> there ?
> >
> > You can solve that with a UPS and/or a gizmo that plugs into a car
> accessory
> > socket.
>
> You still power it down doing that. Power cycle generally isn’t a good
> idea if you
> are after good stability.
>
> >
> > How much does the mechanical jostling as gear gets moved from bench to
> car to
> > table effect the frequency?
>
> If you flip it end for end you might be measuring the “2g tip”
> acceleration sensitivity :).
> That could be up in the 1 to 2 ppb range. Shock and vibe is very much a
> “that depends”
> sort of thing. You could (but probably won’t) see a couple of ppb.
>
> The biggest issue is going to be the changing temperature environment.
> Thermal shock
> is going to create a bigger change than simple temperature change. Going
> from inside
> to outside to car to outside to inside …. each one is a relatively fast
> change. You might
> have a device that held a ppb in a normal temp test and it changes 10X
> that (or more)
> when hit with a relatively modest “fast change”.
>
> Just what’s fast and how much of a change you get is very much a “that
> depends” sort
> of thing. Leave the cover off your OCXO mechanical trimmer and you could
> find that it
> is very sensitive to a gentle gust of wind from the wrong direction ….
>
> Bob
>
> >
> >
> > --
> > These are my opinions.  I hate spam.
> >
> >
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-- 
Jeremy Nichols
Sent from my iPad 6.