[time-nuts] Next Aug 21 eclipse and time flow --> WWV carrier phase
tshoppa at gmail.com
Mon May 29 11:00:23 EDT 2017
Bob, unlike the guys who have many watts of 10MHz running around their labs
via multiple distribution amplifiers, I do not have a big problem with my
dinky 10MHz reference leaking into my radio antenna :-).
This fall the "best band" for WWV for me during daylight eclipse would be
15MHz. 10MHz would have a usable but weaker signal mid-day too.
I was thinking I could synthesize a clean 14.99MHz from my 10MHz, put that
into a mixer along with WWV at 15MHz, and send the 10kHz beat note into one
channel of a PC sound card. The other channel of the sound card could
monitor the Z3801A's 1PPS square wave output, or maybe just the square wave
from dividing 10MHz down to audio frequency square wave. That would allow
me to post-process out any variation in sound card clock.
I should read up on what the FMT guys do. They must do something like this.
I work Connie K5CM almost every week anyway but we are just exchanging
serial numbers, not talking about FMT techniques :-).
On Mon, May 29, 2017 at 8:30 AM, Bob kb8tq <kb8tq at n1k.org> wrote:
> There are a *lot* of SDR boards out there today. The HackRF One is a pretty
> cheap one (you get what you pay for …). They go up to some very expensive
> setups by National Instruments / Ettus. Most of them allow for an external
> input. The usual isolation issues will still apply when checking WWV at 10
> Coming up with isolation vs your local standard will be really tough. I
> would aim
> at 5 and 15 MHz. Of course if you have a Lucent KS box, that sort of rules
> 15 MHz :)
> > On May 29, 2017, at 8:03 AM, Tim Shoppa <tshoppa at gmail.com> wrote:
> > During regular night/day cycles I can just barely observe the night-day
> > shift in WWV propagation from Colorado to my location near Washington DC,
> > using the NTP WWV audio refclock. It amounts to a few hundred
> > of shift. I last touched that code about 15 years ago.
> > Now that I have a 10MHz GPS OCXO (well, I've had that for about 15 years
> > too, getting that was the reason I stopped dinking with the WWV audio
> > refclock) I wonder if there's some simple hardware I could build that
> > let me do superior carrier-phase type measurements on WWV propagation.
> If I
> > could see the night-day shift more clearly then I might see an
> > effect during the upcoming August 21 eclipse, which nicely traces a path
> > from west to east not too far off the line between Ft Collins and my
> > location.
> > Tim N3QE
> > On Sun, May 28, 2017 at 6:17 PM, iovane--- via time-nuts <
> time-nuts at febo.com
> >> wrote:
> >> On august 21 2017 a solar eclipse will sweep USA from coast to coast. A
> >> lifetime opportunity to do coordinated experiments to check this or
> >> One of the questions that doesn't have a final answer yet is whether or
> >> solar eclipses could affect the flow of time. They exist conflicting
> >> reports: Negative: http://www.nature.com/nature/
> >> 402749a0.html Positive: http://home.t01.itscom.net/
> >> allais/blackprior/zhou/zhou-1.pdf http://home.t01.itscom.net/
> >> allais/blackprior/zhou/zhou-2.pdfPersonally I believe that the positive
> >> results were due to spurious responses of the atomic clocks to something
> >> else than gravity, or the clocks failed for some reason (e.g. jumping
> >> crystals then steered), or lower quality clocks had been sold to China.
> >> Anyway the recorded data do show an anomaly.As far as I know, no atomic
> >> clock tests are planned anywhere for that circumstance, but sincerely I
> >> don't believe this is the truth.Maybe the US time-nuts community, using
> >> plenty
> >> of atomic clocks, could give the final answer doing tests during the
> >> above mentioned eclipse.US time-nuts, what about the idea of doing
> >> yourselves a large scale coordinated test? Or do you actually believe
> >> this question is already definitively closed?(Even discovering that
> >> clocks might respond to someting else than gravity would be of great
> >> interest).Antonio I8IOV
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