Mark Posted
I laid out a through-hole version of Warren's board in Eagle
and had OSHPARK fab up three of them.
I sent one to Warren and am using the other two.
The one mod I made was to use a single darlington TO-220 instead
of the two transistor stage that Warren used.
They seem to work quite
Claude
what is the simplest method to measure sub second ADEV?
The answer depends on many unstated things.
Among them is your definition of simple, the Frequency of the DUT, the noise
floor, your budget and your available time..
After budget and frequency, the next most important thing is the
Stu
Thanks for the great information feedback.
No, No, the ~3e-12 is Not an error in the H/W. That would of course cause a
constant phase drift error to accumulate.
The Tbolt has no trouble holding 1e-12 control or even better than 1e-13 when
using the extended time constant mode with an
Stewart
The part that I do not understand is how the TBolt is able to calculate
such high resolution frequency offset answers on its Osc ppt output
so fast. The frequency offset answers seem to have way too high of
absolute accuracy compared to what is possible using the phase data.
Example:
Another unique thing about the TBolt engine is how fast it can calculate a
Freq change in its 10MHz osc.
Over short times periods, it can be 100 times better than a standard 1PPS
GPS engine.
It would be interesting to compare it to a high end dual freq GPS.
With the Tbolt in manual hold over
I second Poul-Henning Kamp's comments concerning D-terms,
(mostly) as done in the TBolt and likely other GPSDOs.
A 'D-term' helps fast loops like a TPLL where you
want a high bandwidth with the P gain as high as possible.
For slow noisy loops like a cleanup osc or a GPSDO,
what helps is a
Authur wrote:
Take a look at the plot where I adjust a rubidium standard and see what you
think.
I think it is a great idea, and shows that LadyHeather and a modified TBolt
can make a great high end, stand alone Time-Nut tester without the need of a
reference osc or offset osc, or any other
Some of the reasons that ADEV values change over time may be
caused by one of these two things that I have seen cause poor plots.
Either of which can cause changes in the ADEV values across
a wide range of taus, and the effect can change over long run ins.
Hopefully Magnus will comment if ADEV
Bob Camp posted (Wed Oct 22 20:38:47 EDT 2014)
Re: [time-nuts] Phase, One edge or two?
ADEV most certainly does change with time, even for short tau's.
Can you elaborate?
Such as when, why, what kind of change, how much change,
at how short of tau's, over how long of time,
and using what
Poul said;
If you tell me it is a sine and give me the time of two zero crossings
I can tell you everything there has or ever will be to know ...
just to add a bit more nut picking on comment #3.
When talking about sub picosecond per second time nut type accuracy, there
is no such thing as
Lots of interesting responses,
but I did not see any posted that answered the original question:
Is the CERN method described in the paper the best way to make a state of
the art femtosecond DDMDT?
www.ee.ucl.ac.uk/lcs/previous/LCS2011/LCS1136.pdf
Restating
Assuming it is kept Digital, and not
The recent discussions about the simple digital mixer got me thinking about
the performance vs. complexity trade offs when measuring accurate, high
resolution, phase drift differences between two oscillators.
It would seem to me, that using both the positive and negative slope edges
of the
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