How often Lady Heather gets a satellite position report depends upon the
receiver type. It can range from every second to once per minute.
-
> (there seems to be some finite latency in LH's constellation reports, but I'm
> not sure how
much -- perhaps Mark will comment).
Hi
A little about the “why” of all this ….
Few of us have ideal antenna locations. Even what we consider to be “really
good” is still
quite a ways from ideal. A concrete tower 50’ above everything else with a
clear view of
the sky down to zero degrees in every direction is “ideal”. Due to
I think you may be missing the most likely primary contributor.
Each GPS receiver (and, thus, each GPSDO) tracks a constantly-changing
"constellation" of satellites. Each rx switches constellations as it
sees fit, depending on reception conditions as it sees them, and no two
receivers will
I think I have a setup that exemplifies this situation, and some
anecdotes. A while back, I acquired two "identical" GPSDO boards, and
boxed them up together, with common environment, power supply, and GPS
signal via a splitter. I've mentioned this thing a couple of times here,
and had planned
Hi
Ok
> On May 31, 2019, at 4:48 PM, life speed via time-nuts
> wrote:
>
> On Friday, May 31, 2019, 5:18:32 AM PDT, Bob kb8tq wrote:
>
> Hi
>
> One term you keep tossing up is “nominal phase coherence”. Typical GPS will
> do “phase coherence”
> at the 10 ns level to a fairly high
On Friday, May 31, 2019, 5:18:32 AM PDT, Bob kb8tq wrote:
Hi
One term you keep tossing up is “nominal phase coherence”. Typical GPS will do
“phase coherence”
at the 10 ns level to a fairly high degree of confidence (90 something percent)
with a number of
footnotes. You have never
Hi
One term you keep tossing up is “nominal phase coherence”. Typical GPS will do
“phase coherence”
at the 10 ns level to a fairly high degree of confidence (90 something percent)
with a number of
footnotes. You have never mentioned what your requirement is so it’s a bit
tough to know what
> 2) I think I understand this. Further I will have to understand what the
> optimal PLL BW is in light of the OCXO short-term ADEV being potentially
> better than GPS 1PPS with correction. Perhaps this means the loop BW should
> be on the order of a milliHertz, if it takes 1000 seconds for
Hi
Without a deep dive into the physics of GPS, there is not a good way to
demonstrate
just *why* the solution is as bad as it is on a second to second basis. There
is no magic
“silver bullet” that will suddenly turn it from an ADEV of 1x10^-9 into an ADEV
of 1x10^-13
at one second. The
2. Re: GPS 1PPS, phase lock vs frequency lock, design (Bob kb8tq)
Hi
The TBolt is a very unique design. It directly uses code phase information
against the OCXO. The net result is really no different than the “correction
message” approach, but it is a different implementation. Since you
Hi
The TBolt is a very unique design. It directly uses code phase information
against the OCXO. The net result is really no different than the “correction
message” approach, but it is a different implementation. Since you can’t
*buy* the guts of a TBolt to strap into a DIY GPSDO, it’s not
On 2019-05-29 14:53, Attila Kinali wrote:
The saw-tooth correction is the error of the PPS signal, as generated by
the hardware, and where it really should be. The clocks of most GPS receivers
are in the order of 20-60MHz and are usually unsteered TCXOs (or even XO for
the cheap ones). Hence the
On Wed, 29 May 2019 14:53:07 +0200
Attila Kinali wrote:
> > 2) I think I understand this. Further I will have to understand what the
> > optimal PLL BW is in light of the OCXO short-term ADEV being potentially
> > better than GPS 1PPS with correction. Perhaps this means the loop BW
> >
On Tue, 28 May 2019 18:39:34 + (UTC)
life speed via time-nuts wrote:
> Attila,
> Thanks for taking the time to respond and share your practical experiences in
> this area. Your explanations are very helpful, I have a few more questions
> if you don't mind:
> 1) Would you elaborate on the
On Sunday, May 26, 2019, 7:24:31 AM PDT, Attila Kinali
wrote:
As you state that you are familiar with PLL design, I guess your confusion
comes from having a 1Hz signal and trying to use that for a "normal" phase
detector. While this is possible and can be done, it leads imediatly to
the
Apologies, teletype did not let the picture through
http://www.leobodnar.com/files/2x%20ECOC%203v6.png
> I had half a dozen of 38.88MHz ones for tinkering.
> There is nothing exciting about them apart from a noisy LDO which has peaking
> around 70kHz.
> Spurs are mine.
> Leo
On Sat, 25 May 2019 00:51:46 + (UTC)
life speed via time-nuts wrote:
> I want to discipline a 10 MHz OCXO with 1PPS from GPS. Obviously not an
> unusual application, but I need to understand the methodology as I will not
> be buying a module but rather implementing the design with an
I had half a dozen of 38.88MHz ones for tinkering.
There is nothing exciting about them apart from a noisy LDO which has peaking
around 70kHz.
Spurs are mine.
Leo
On 25 May 2019, at 17:00, Gerhard Hoffmann wrote:
> Has anybody out there more information about this oscillator?
> Its data
Am 25.05.19 um 02:51 schrieb life speed via time-nuts:
Hi all, it's been a while since I visited. I am venturing into an unfamiliar
area from my usual low phase noise PLL, OCXO and microwave synthesizer design
endeavors.
I recall there are some knowledgeable, well, time nuts on this list and
Hi all, it's been a while since I visited. I am venturing into an unfamiliar
area from my usual low phase noise PLL, OCXO and microwave synthesizer design
endeavors.
I recall there are some knowledgeable, well, time nuts on this list and hope
you'll indulge some questions and maybe direct me
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