Hi Michael,
You Wrote:
We are using BeagleBone Black + GPS 1 pps etc in our time-transfer system
You can see the overlays in
https://github.com/openttp/openttp/tree/develop/software/system/device-tree-overlays
Very interesting, I will have to clone the git repo, and have a closer
look.
I ha
The SV6 has three different firmware versions for the following protocols:
NMEA, TSIP, and TAIP.
The latest Lady Heather code(5.01 or later) does support all the SV6 versions.
You could pull the receiver and wire it to a TTL-RS232 converter and maybe get
some more info on what it is doing.
Hello Jim
We are using BeagleBone Black + GPS 1 pps etc in our time-transfer system
You can see the overlays in
https://github.com/openttp/openttp/tree/develop/software/system/device-tree-overlays
Best regards
Michael
On Wed, Oct 25, 2017 at 11:43 AM, jimlux wrote:
> On 10/24/17 5:04 PM, Nick
I did log the #TIME message for several weeks on an OEMV-3 a while back.
The results were a bit suspicious, so I checked with Novatel support -
turns out the PPS on the OEMV (and I presume that also holds for OEM4) is
derived from L1 only - and the jitter is nothing to brag about. So for
disciplini
> The SV6's are all well past their rollover date.
>
>A common problem with the SV6 (and the Motorola 6 and 8 channel receivers) is
>the TCXO has drifted out of range. Some have an adjustment cap that can be
>tweaked.
I'll look into that. For the moment it appears that separating the TS2100
On 10/24/17 5:04 PM, Nick Sayer via time-nuts wrote:
FWIW, I’ve documented the whole R-Pi GPS NTP thing at
https://hackaday.io/project/15137
As a disclaimer I will also say that I’m not even remotely the first. But
what’s kind of nice is that I have a R-Pi desk clock display board that plays
FWIW, I’ve documented the whole R-Pi GPS NTP thing at
https://hackaday.io/project/15137
As a disclaimer I will also say that I’m not even remotely the first. But
what’s kind of nice is that I have a R-Pi desk clock display board that plays
really well with a bolt-on GPS cap. In fact, I’ve got t
Hi
The “best” approach would be to use a receiver that reports what’s going on to
some pretty
good resolution (say picoseconds). You also measure the pps offset (say to
picoseconds).
Then you feed *both* numbers into a software loop.
Since you are after a loop with a “many days” sort of respo
Hello Skip,
I have a theory, but it will be interesting to see what others say.
Assuming that the
1 PPS error to which you refer is the so-called "sawtooth" error, I've come
to suspect
that the rate at which the individual PPS pulses walk across the sawtooth
is related to,
and likely proportional
On 10/24/17 11:54 AM, Bob kb8tq wrote:
Hi
If you have the money, almost anything can be (and has been) done. It’s rare to
find a
real world application where this kind of thing is considered cost effective.
Fancy
radar systems are about the only thing that comes to mind. Radar of
this sort is
Skip,
I would rather use the rich Novatel reports and read out the time error
and use that as your phase detector, then the normal PI-loop stuff with
an optional low-pass to add and then use that to steer the rubidium.
It's one of those, when I get time, projects.
Cheers,
Magnus
On 10/25/20
Hello time-nuts,
I've been thinking about a GPS receiver experiment and just wondering
if there are any opinions or prior experience that might save me a lot
of time.
What I have been thinking about doing is taking a GPS receiver
(Novatel OEM4-G2) that has provisions for an external clock (5 or 1
Hi
If you have the money, almost anything can be (and has been) done. It’s rare to
find a
real world application where this kind of thing is considered cost effective.
Fancy
radar systems are about the only thing that comes to mind. Radar of
this sort is always high cost / low volume.
Bob
On 10/24/2017 11:10 AM, Hal Murray wrote:
aph...@comcast.net said:
My applications were broadband. If I remember correctly, aggressive
bandwidth limiting can cause phase shift problems due to temperature
changes unless one is careful in the design of the filter.
Does anybody ovenize ampl
aph...@comcast.net said:
> My applications were broadband. If I remember correctly, aggressive
> bandwidth limiting can cause phase shift problems due to temperature
> changes unless one is careful in the design of the filter.
Does anybody ovenize amplifiers and filters to avoid that problem
I never had much luck with current feedback amplifiers such as the
LMH6702. Their input current noise (at the time) was too high for
my needs and their output peaks at higher frequencies if the
feedback resistors aren't optimal for the part.
I had the best results with voltage feedback op am
Hi,
> Is it safe to have RG174 coming out of the
GPSDO, tapping into it with a BNC T-junction that plugs into the back of
each device that needs the 10mhz input, and then terminating the strand
with a 50 ohm terminator?
Besides the usual signal integrity issues, remember to provide a solid
earth
Hi
One would guess that they put them in parallel to get more drive. If that’s
correct,
details of the loading are going to get into the simulation pretty quickly.
In a lot of cases, these amplifiers were designed against a specific need. If
you have
a signal source that is in the -180 dbc / H
FWIW I recently took a peek inside a commercial distribution-amplifier and
it seems to use two LMH6702 op-amps in parallel.
There are two of these dual-LMH6702 stages with a 1:2 splitter after the
first, and then a 1:4 splitter after the second stage. 8 outputs in total,
with an additional op-amp d
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