On Thu, 7 May 2015 14:43:44 -0400
Tim Shoppa wrote:
> Gotcha with modulating the PPS onto a RF carrier, is that for time
> resolution of 1 nanosecond, you would end up using a Gigahertz of bandwidth.
Not really. You are not doing detection in frequency space
or of an infintely sharp pulse. As su
tsho...@gmail.com said:
> Gotcha with modulating the PPS onto a RF carrier, is that for time
> resolution of 1 nanosecond, you would end up using a Gigahertz of bandwidth.
You might be able to use near-field antennas. Picture 2 PCBs spaced a few mm
apart with circular antennas. It would be int
Hi
> On May 7, 2015, at 8:02 AM, Pete Stephenson wrote:
>
> On 5/7/2015 1:22 PM, Bob Camp wrote:
>> Hi
>>
>> I guess on a general level:
>>
>> 1) How do they generate the Swiss version of UTC (fleet of hydrogen masers
>> run into to a .. :)
>
> According to their website they use an ensembl
Anyone have specs and a pinout for the Frequency electronics FE-2294B
oscillator?
Thanks,
Corby
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On Thu, 7 May 2015 08:18:05 -0700
"Tom Van Baak" wrote:
> Attila,
>
> My thought was to put PHK's proposed experiment entirely on the rotating
> table: antenna, receiver, local Cs standard, laptop, and battery.
Then you have to be carefull, that the rotation does not modulate
the reference. I
On Thu, 7 May 2015 20:57:56 +0200
"Björn Gabrielsson" wrote:
>http://www.navipedia.net/index.php/Carrier_Phase_Wind-up_Effect
This page referes to
Wu, J., Wu, S., Hajj, G., Bertiguer, W. and Lichten, S., 1993. Effects of
Antenna Orientation on GPS Carrier Phase Measurements. Manuscripta Ge
On 5/7/15 7:23 AM, Attila Kinali wrote:
On Sun, 03 May 2015 07:29:30 +
"Poul-Henning Kamp" wrote:
When you post-process raw GPS data you get to include antenna phase
center / gain / az/el corrections for free.
Speaking of which...
I wonder if anybody ever made a rotating GPS antenna to
How about a laser diode and pin photo detector? You should be able to get
nanosecond resolution with light.
- Original Message -
From: "Tim Shoppa"
To: "Discussion of precise time and frequency measurement"
Sent: Thursday, May 07, 2015 2:43 PM
Subject: Re: [time-nuts] Important par
Also consider phase wind up.
http://www.navipedia.net/index.php/Carrier_Phase_Wind-up_Effect
Sure there are also some papers on rotating antennas.
http://www.researchgate.net/profile/Simon_Banville/publication/257945217_Antenna_Rotation_and_Its_Effects_on_Kinematic_Precise_Point_Positioning/l
Personally I would be happy with PPS time resolution at 10 nanoseconds but
others would want better than a nanosecond.
Gotcha with modulating the PPS onto a RF carrier, is that for time
resolution of 1 nanosecond, you would end up using a Gigahertz of bandwidth.
Tim N3QE
On Thu, May 7, 2015 at
I'm curious whether it would need 360 degree rotation? Would simply cycling
about 120 degrees on the end of a short arm be just as good and could be done
without a rotary joint? I understand that now the RX is moving but within a
small radius would it be unbearable? Or would 300 degrees around t
Just put the GPS antenna, receiver, battery, and a low power RF
transmitter modulated by the PPS (wide bandwidth = fast edge time) on
the turntable, then use an appropriate receiver to demodulate the PPS
and feed it to the rest of the system. Put the RX antenna directly
above (or below) the tu
A 300M error is not "just a GPS determination" but is likely the phone
using a few extrapolated stale GPS readings maybe combined with some kind
(probably wrong kind) of dead reckoning.
Automotive dead reckoning applied to pedestrian movement can produce really
interesting results! As I walk aroun
>> I wonder if anybody ever made a rotating GPS antenna to average out the
>> X-Y phase-center offset ?
> Of course, this does not really work with a gps antenna, unless you
> put the whole receiver onto the rotary table. But then you shift
> the problem onto the PPS output (note: amplitude noise
On Sun, 03 May 2015 07:29:30 +
"Poul-Henning Kamp" wrote:
> >When you post-process raw GPS data you get to include antenna phase
> >center / gain / az/el corrections for free.
>
> Speaking of which...
>
> I wonder if anybody ever made a rotating GPS antenna to average out the
> X-Y phase-ce
On Sat, 02 May 2015 18:36:30 +0200
Magnus Danielson wrote:
> On 04/29/2015 10:43 PM, Attila Kinali wrote:
> > Moin,
> >
> > I recently discovered openEMS[1], which is, very simply put, a fancy
> > antenna simulator. I played a little with it and thought about
> > trying to optimize an GPS patch a
On Sat, 2 May 2015 13:25:16 -0400
Bob Camp wrote:
> Phase / delay stability over temperature would be an interesting thing
> to look at. Probably not a big deal on
> a simple antenna. It might be an issue as the antenna interacts with the
> preamp and filter.
I've seen a couple of papers concer
On 5/7/2015 1:22 PM, Bob Camp wrote:
> Hi
>
> I guess on a general level:
>
> 1) How do they generate the Swiss version of UTC (fleet of hydrogen masers
> run into to a .. :)
According to their website they use an ensemble of commercial cesium
clocks (they show some photos of HP 5071As) and a h
On Tue, 5 May 2015 22:01:29 +
Mark Sims wrote:
> Should be fun when it becomes available... they claim they can get
> accurate carrier phase info using a cheap antenna in the phone...
> and in real time. It should also be able to get accurate time.
> http://www.eurekalert.org/pub_releases
Poul-Henning Kamp wrote:
Ask them how/why the HBG transmitter screwed up the 2006 leapsecond ?
If I remember correctly then the transmitter would have needed to be
overhauled, which would have been very expensive.
Since the German DCF77 transmitter can also be received in Switzerland
and DC
In message <7fa86d93-1c83-4fe8-84a0-ddb7a542a...@n1k.org>, Bob Camp writes:
Ask them how/why the HBG transmitter screwed up the 2006 leapsecond ?
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
p...@freebsd.org | TCP/IP since RFC 956
FreeBSD committer | BSD since 4
Hi
I guess on a general level:
1) How do they generate the Swiss version of UTC (fleet of hydrogen masers run
into to a .. :)
2) How do they link that version of UTC with the rest of the world? (BIH etc)
Not so much a picture of this or that. More a tour of an entire process.
Bob
> On May 7
Be aware that the early TS2100's have different (SV6) gps receivers
than the later (ACE III) ones. Both speak TSIP, but some of the
commands are different.
Mine went to the boneyard a few months ago.
On Wed, May 6, 2015 at 9:28 PM, Sean Gallagher wrote:
>
>
> It's possible that the Heol Design
Brian Inglis wrote:
The next rollover is about April 2019, but this can happen any time
an older receiver's internal date representation used for GPS to UTC
conversion overflows. Looks like Tymserve 2100 picked about Sep 1995
for its date epoch so it hits now.
Newer GPS receivers support the ext
Look also at Brandywine and Meinberg.
/Björn
Originalmeddelande Från: Andrew Cooper
Datum:2015-05-06 21:58 (GMT+01:00)
Till: time-nuts@febo.com Rubrik: [time-nuts] Microsemi
versus Spetracom
So, yes, our old TS2100's suffered the 1995 bug over the weekend like all
of the
Hi all,
I recently inquired about taking a tour of the METAS time lab[1] and
they said they'd be willing to show me around.
Is there anything in particular that fellow time-nuts would be
interested in me asking them about or (if possible) photographing?
Cheers!
-Pete
[1] http://www.metas.ch/met
It's possible that the Heol Design Trimble III replacement cards (N014 & N024)
will correct the 1995 issue. They are sending my company a couple now for us to
test in a trusted time infrastructure which includes 2 TS2100's. Unfortunately
they were not able to get a straight answer from Tri
On 5/6/15 3:09 PM, Bob Camp wrote:
GPS helix antennas were a really big deal in about 1982. Once people started to
get experience with GPS and a variety of designs, they became less of a big
deal. I do not know of any modern
precision antennas that use a helix.
Most precision antennas I've
That's what mine is doing. The hourglass stops and a random ascii
character appears overlapped with the top left corner of the hourglass.
David and Brian, I'll ping you guys off list so we don't clutter this place
up.
Thanks,
Bob
On Wed, May 6, 2015 at 4:58 PM, David & Laura
wrote:
> I had thi
On 5/6/2015 3:24 PM, Bob Camp wrote:
Hi
A standard input on a frequency counter is not a very demanding thing in the
hierarchy of
TimeNut signals. You can drive any of them with some pretty simple logic gate
based
circuits. No need to spend a lot of money.
Bob
Logic gate, yes. Comparat
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