In order to add Truetime XL-DC (and XLi support) to Lady Heather, I bought an
XL-DC that happened to have the FTM-III module in it. This module is designed
to measure power line frequency for generating stations, etc, It works well,
but the minimum integration time is one second. You can
On 7/3/19 3:20 PM, Jeremy Nichols wrote:
The station at Santa Rosa, California (#853 in the Western Interconnection)
is mine. Have had their receiver for several years. Only downside is that i
can't record the data directly from the supplied receiver.
Jeremy
but what can you tell us about
The station at Santa Rosa, California (#853 in the Western Interconnection)
is mine. Have had their receiver for several years. Only downside is that i
can't record the data directly from the supplied receiver.
Jeremy
On Wed, Jul 3, 2019 at 12:01 PM Paul Theodoropoulos via time-nuts <
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
This stuff is fascinating to a time-nut-level:Novice such as myself.
While falling down the rabbit-hole searching on all the various bits of
the info below, I ran across this - not sure if you're aware of it, or
if it's old news, but it seems at least peripherally interesting:
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
Wow Tom that is great work! I won't pretend to understand what you did and
how you did it or, even, what the various graphs represent. But one thing I
get out of it is the amazing correlation of measurements made across such a
distance. And the equally amazing accuracy, stability, and
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
On 7/3/19 8:56 AM, Tom Van Baak wrote:
Bob,
Several of us do long-term measurement of mains frequency. We tend to
time-stamp cycles and then compute period or frequency, rather than
measuring frequency or period directly. Traditional counters in gated
frequency or time interval mode have
On 7/2/19 11:47 PM, Hal Murray wrote:
jim...@earthlink.net said:
Actually, it's because someone asked me about a science experiment where
you'd place them in a neighborhood outdoors.
Sounds like another science experiment: build an antenna to pick up 60 Hz.
You could start with the typical
Bob,
Several of us do long-term measurement of mains frequency. We tend to
time-stamp cycles and then compute period or frequency, rather than
measuring frequency or period directly. Traditional counters in gated
frequency or time interval mode have dead time and this will skew results.
In
> 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
>
Jim, almost any mains powered lighting has a substantial 120Hz component in
light intensity. It's quite reasonable to trigger off this at nighttime if
the light is on and only that single light is in field of view of a
phototransistor (no car headlights allowed to come into view!)
It's still far
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
On 7/2/19 10:09 PM, Bob Albert via time-nuts wrote:
I have tried to measure the power line frequency with spotty success. My
best results came from a period measurement, as many periods as the counter can
accumulate. Due to noise, one is never sure at quite what point the source is
jim...@earthlink.net said:
> Actually, it's because someone asked me about a science experiment where
> you'd place them in a neighborhood outdoors.
Sounds like another science experiment: build an antenna to pick up 60 Hz.
You could start with the typical ferrite, coil, and cap. Just adjust
I'd normally use an optocoupler.
But it doesn't need to be an 8-pin dip with the mains and low-voltage pins
0.3" apart - it can be a neon lamp and a photodiode, or a photodiode near a
mains-fed lamp. Even an incandescent has a very strong modulation of the
light. You just need to avoid leds that
I have tried to measure the power line frequency with spotty success. My best
results came from a period measurement, as many periods as the counter can
accumulate. Due to noise, one is never sure at quite what point the source is
measured. Perhaps a brick wall filter would clean it up for
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