[time-nuts] Next Aug 21 eclipse and time flow --> WWV carrier phase
kb8tq at n1k.org
Mon May 29 12:06:43 EDT 2017
The gotcha with carrier phase is that it is a bit more sensitive to local signals
than your ear is. Yes, a lot depends on your antenna setup and as you mention,
just how many watts of distribution and thousands of feet of cable you are running
10 MHz through.
> On May 29, 2017, at 11:00 AM, Tim Shoppa <tshoppa at gmail.com> wrote:
> 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 :-).
> Tim N3QE
> 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
>>> Tim N3QE
>>> On Sun, May 28, 2017 at 6:17 PM, iovane--- via time-nuts <
>> time-nuts at febo.com
>>>> 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
>>>> 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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