Hi
> On Nov 13, 2016, at 9:34 AM, Artek Manuals wrote:
>
> Tom et all
>
> While our instinct based on some "pre- knowledge" of the aging and drift
> processes is to try and fit these to linear or logarithmic curves there is a
> third possibility . That is, in fact the aging is not exactly e
>> http://leapsecond.com/pages/tbolt/TBolt-10day-fit1-e10.gif
> Hi Tom,
>
> Fascinating when you've done that linear fit - many of the plots now look
> very similar,
> suggesting environmental conditions? From that it would now be nice to log
> temperature,
> pressure, humidity, (& mains voltag
Hi Tom,
Fascinating when you've done that linear fit - many of the plots now
look very similar, suggesting environmental conditions? From that it would
now be nice to log temperature, pressure, humidity, (& mains voltage?), and
see if there is any correlation there.
Wonderful to see pl
Tom et all
While our instinct based on some "pre- knowledge" of the aging and drift
processes is to try and fit these to linear or logarithmic curves there
is a third possibility . That is, in fact the aging is not exactly
either and may be better represented in fact be some kind of polynomial
Thanks for all the comments on this thread. Here is the first set of replies:
Don Latham:
> Interesting, Tom. I don't think I see any of those pesky grain boundary
> shifts or readjustments in the lattice structure? If I remember, these
> can cause instant shifts in frequency that do not h
Hi
Exact info on mass transfer is a bit complicated. A 5 MHz 5th overtone is
a bit thicker and more massive than a 100 MHz 5th. Both are thicker (and
more massive) than a 100 MHz fundamental. On top of that the blank is not
equally sensitive to mass at all points on it’s surface. Finally, gold
Those are wonderful plots :)
I vaguely recall that a 1ppm frequency shift is approximately equivalent to
the mass transfer of one molecular layer of a crystal. So at some point
your counting atoms if there was no noise, thermal disturbance, mechanical
disturbance...
On Sat, Nov 12, 2016 at 5:00 P
Attila wrote:
Yes, depending on the data you show, it is not clear
whether one should do a linear or a logarithmic fit.
When the purpose is correcting a GPSDO local oscillator during holdover,
it depends on how long one expects to trust the corrected frequency.
Practical realities make it po
On 11/12/16 1:54 PM, Tom Van Baak wrote:
There were postings recently about OCXO ageing, or drift rates.
I've been testing a batch of TBolts for a couple of months and it provides an
interesting set of data from which to make visual answers to recent questions.
Here are three plots.
The plots
Just out of curiosity, what is the age of each of these Tbolts? (i.e. date
codes?)
Thanks
- Original Message -
From: "Tom Van Baak"
To: "Discussion of precise time and frequency measurement"
Sent: Saturday, November 12, 2016 4:54 PM
Subject: [time-nuts
: Saturday, November 12, 2016 3:54 PM
Subject: [time-nuts] quartz drift rates, linear or log
There were postings recently about OCXO ageing, or drift rates.
I've been testing a batch of TBolts for a couple of months and it provides an
interesting set of data from which to make visual answers to r
Hi
One would *guess* that the OCXO’s all left the factory set to center at zero
volts on the EFC. One thing
that is pretty easy to do is to look at the date code on the OCXO and the EFC
voltage. That plus the
sensitivity (one could cheat and look at the frequency rather than EFC) will
give you
On Sat, 12 Nov 2016 13:54:14 -0800
"Tom Van Baak" wrote:
> 2) attached plot: TBolt-10day-fit0-e10.gif (
> http://leapsecond.com/pages/tbolt/TBolt-10day-fit0-e10.gif )
>
> Here we zoom in by changing the Y-scale to 1e-10 per division. The X-scale
> is still 10 days. Now we can see the drift muc
Interesting, Tom. I don't think I see any of those pesky grain boundary
shifts or readjustments in the lattice structure? If I remember, these
can cause instant shifts in frequency that do not heal?
Don
On 2016-11-12 14:54, Tom Van Baak wrote:
There were postings recently about OCXO ageing, o
There were postings recently about OCXO ageing, or drift rates.
I've been testing a batch of TBolts for a couple of months and it provides an
interesting set of data from which to make visual answers to recent questions.
Here are three plots.
1) attached plot: TBolt-10day-fit0-e09.gif (
http:
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