Hi
If the data is GPS referenced it is not at all uncommon to see a roughly 24
hour pattern in
the data. Ionospheric changes are one significant contributor. The further down
into the
mud you get, the more other things pop up (multipath repeating with the same
constalation
….)
Bob
> On
Hello David,
It could quite possibly be tempco induced. I have this on my schedule of
future events for additional analysis.
Thanks,
Chris
Chris,
Just looking at the graph reminds me of a daily variation - perhaps
due to temperature. Is that likely? Would a two-day graph be worth
Hi Dana,
My PRS10 is the DUT that has its 1PPS(Out) wired into the TICC on ChA.
The reference is my GPSDO which has a 8663-XS DOCXO and has its
1PPS(Out) wired into the TICC on ChB. The 10 MHz clock signal for the
TICC comes from my GPSDO also, which as I understand, need not be quite
so
> I'm just curious if the phase difference slope value can be plugged
in to this equation.
> I'm seeing 4.22E-12 as the slope value in the upper right of the
> TimeLab phase difference plot. Is that telling me that my DUT is
> within +4.22ps / sec from my reference 1PPS for the 24 hour
>
Chris,
Ok, one source is a PRS-10. Is it the DUT or the reference? And if it's
the DUT, what
is the reference source?
Dana
On Tue, Jul 2, 2019 at 8:00 PM Chris Burford
wrote:
> Hi Bob,
>
> I'm seeing 4.22E-12 as the slope value in the upper right of the TimeLab
> phase difference plot. Is
Hi Bob,
I'm seeing 4.22E-12 as the slope value in the upper right of the TimeLab
phase difference plot. Is that telling me that my DUT is within +4.22ps
/ sec from my reference 1PPS for the 24 hour measurement duration?
I have attached a screen capture that will hopefully make its way
through
Hi Bob,
I'm seeing 4.22E-12 as the slope value in the upper right of the TimeLab
phase difference plot. Is that telling me that my DUT is within +4.22ps
/ sec from my reference 1PPS for the 24 hour measurement duration?
I have attached a screen capture that will hopefully make its way
Hi
The gotcha is that if the duration gets long enough, the numbers on a GPSDO
will get silly small.
You very much have to decide what time duration is appropriate to your system /
application. If you
always run your frequency counter on a 1 or 10 second gate …. you really don’t
care about
Hi
The difference in seconds between the start phase and the end phase divided by
the number
of seconds duration gives you the parts in whatever of the error.
If you see 1us ( = 1x10^-6 seconds) of change in a second, you are off by 1
ppm (or 1x10^-6).
If you see 1 us of change in 1,000
Is the slope value for the phase difference shown in TimeLab an average
of the overall data sample duration? The reason I ask is that my service
manual for my RFS says:
/"//A faster way to make the comparison between the reference frequency
and the DUT is to use the time interval measurement
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