On 10/10/2012 06:30 AM, Hal Murray wrote:
albertson.ch...@gmail.com said:
The satellites are in 12 hour orbits. Everything repeats every 12 hours.
But the sun is on a 24 hr. period and if you did two 12 hour tests you don't
want to do one at night and one in day. So start each test at the
Hi!
I forgot to mention, but the peak group delay of a pole pair is d_peak =
2*Q/w0 = Q / (pi * f0)
Hence, the group delay increases linearly with increasing Q values.
Shift the Q, and your delay vary, shift the center-frequency, and you
dip off the peak.
Cheers,
Magnus
On 10/09/2012
Hi
…. and if we have to go to something more exotic than simple two pole filters
the group delay (and it's variation) has got to go up.
At least some of the HP splitters have RF filters in them. The same is true of
GPS receivers. A receiver or splitter in the attic will have many of the same
On 10/10/2012 8:00 AM, time-nuts-requ...@febo.com wrote:
albertson.ch...@gmail.com said:
The satellites are in 12 hour orbits. Everything repeats every 12 hours.
But the sun is on a 24 hr. period and if you did two 12 hour tests you don't
want to do one at night and one in day. So start
Hi:
The reason for the GPS orbits is so that the ground track repeats.
Have Fun,
Brooke
On 10/10/2012 8:00 AM, time-nuts-requ...@febo.com wrote:
albertson.ch...@gmail.com said:
The satellites are in 12 hour orbits. Everything repeats every 12
hours.
But the sun is on a 24 hr. period
On 10/10/12 8:10 AM, bro...@pacific.net wrote:
Hi:
The reason for the GPS orbits is so that the ground track repeats.
Have Fun,
Brooke
and that makes it easy to predict visibility. Tomorrow will be the same
as today, shifted by 4 minutes.
___
. Tomorrow will be the same as today, shifted by 4 minutes.
Seems to work as a predictor for a lot of things :)...
Bob
___
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On 10/10/2012 01:09 PM, Bob Camp wrote:
Hi
…. and if we have to go to something more exotic than simple two pole filters
the group delay (and it's variation) has got to go up.
Yes and no.
As you add pole-pairs, their group delay contributions adds up. However,
as you add pole-pairs you
On Oct 10, 2012, at 5:05 PM, Magnus Danielson mag...@rubidium.dyndns.org
wrote:
On 10/10/2012 01:09 PM, Bob Camp wrote:
Hi
…. and if we have to go to something more exotic than simple two pole
filters the group delay (and it's variation) has got to go up.
Yes and no.
As you add
On 10/11/2012 12:03 AM, Bob Camp wrote:
On Oct 10, 2012, at 5:05 PM, Magnus Danielsonmag...@rubidium.dyndns.org
wrote:
On 10/10/2012 01:09 PM, Bob Camp wrote:
Hi
…. and if we have to go to something more exotic than simple two pole filters
the group delay (and it's variation) has got to
On Oct 10, 2012, at 7:03 PM, Magnus Danielson mag...@rubidium.dyndns.org
wrote:
On 10/11/2012 12:03 AM, Bob Camp wrote:
On Oct 10, 2012, at 5:05 PM, Magnus Danielsonmag...@rubidium.dyndns.org
wrote:
On 10/10/2012 01:09 PM, Bob Camp wrote:
Hi
…. and if we have to go to something
mag...@rubidium.dyndns.org said:
I do know those that temperature stabilizes both the concrete pillar and
cable conduct.
I hadn't thought about the support pillar. CTE of concrete is 8-12 PPM/C, so
a 10 C change would be 100 PPM. 10 meters would be 1000 micrometers or 1 mm.
I think
Crosstalk? With the same signal?
On Tue, Oct 9, 2012 at 4:31 AM, Edgardo Molina xe1...@amsat.org wrote:
Dear Group,
Good evening. I just arrived home after the first day of conferences at
the Electrical Metrology Forum 2012 at Mexico's metrology center CENAM. I
attended several
I was wondering about that myself, but my guess is the crosstalk would
be from whatever grunge was coming from the other GPS. Every amplifier
has reverse parameters, so a small amount of the crud (circuitry noise)
from one GPS will reach the other GPS. Not much, but some people are
nuts about
This article discusses timing errors due to mismatch and multiple
reflections in transmissin lines:
http://www.dtic.mil/dtic/tr/fulltext/u2/a508044.pdf
Adrian
Edgardo Molina schrieb:
Dear Group,
Good evening. I just arrived home after the first day of conferences at the
Electrical Metrology
Hi all,
In my shack I have a single antenna with two power splitter in series
because I need several ports for the four GPSDO and spare port for
occasional testing.
1.1 They argued that cross talk could happen among ports. I doubt it
with the newer models. I have experience with
Is there any difference between what a GPS receiver can receve via
crosstalk or receive directly from the antenna? In my opinion crosstalk is
absolutely less than the last argument about GPS antenna splitters.
On Tue, Oct 9, 2012 at 9:58 AM, Timeok tim...@timeok.it wrote:
Hi all,
In my shack
I agree,
Luciano
timeok
Il 2012-10-09 10:41 Azelio Boriani ha scritto:
Is there any difference between what a GPS receiver can receve via
crosstalk or receive directly from the antenna? In my opinion
crosstalk is
absolutely less than the last argument about GPS antenna splitters.
On Tue, Oct
When GPS first started to be fitted to light aircraft it was found that LO
leakage from some VHF navigation recivers blocked the GPS when the NAV was on
certain channels. You can buy a BNC T adaptor where the leg of the T is a
1.5GHz coax stub notch filter. They go on the NAV RX antenna
Lots of comments. Indeed it sounds like a great discussion for pizza and
beer. The more beer the more lively. Did they bring beer?
Fact
I have used a 8 way splitter Sat/TV for 5 years now. Port to port loss is
something like 16 db or 26 db as I recall. It has dc blocking on all but 1
port built
Paul,
I am convinced your realization work very well and it is a lower cost
in the market.
But depend what kind of user have to use the device.
For a standard laboratory or a company I am sure is not sufficent your
realization, for an hobbist yes, can be.
Business or research company want
Hello All -
I do not believe there is a hard Yes or No answer for this question.
It depends upon the performance specification of the system elements
and the system requirements.
For instance if the leakage of noise and discrete signals from each
receiver out
of the antenna port combined with
Hi
If you look at the way NIST sets up one of their time modem installations,
they do indeed worry a lot about this sort of stuff. There's a major choke /
isolator between the antenna and the feed line. The claim is that they see
in building grunge causing trouble without it. I'm sure that will
Yes indeed its a depends since in the original thread there was not a
specific requirement.
But as you say its a design. If you do not want to design makes more sense
to grab a ebay wonder I suspect. For me I had fun designing and saving a
buck. 8 ports verses 2...
Regards
Paul
WB8TSL
On Tue, Oct
I believe it is possible for splitters to be invisible to your system. My first
choice would be multiple Antennas. But if you have multiple GPS receivers and
require outputs to your test bench, splitters are the logical choice. That said
the splitter adds complexity to the system and
Suppose I wanted to do an experiment with GPS receivers: Is setup A better
than setup B? But they share some parts, say the antenna, so I can't run
them both at the same time.
How long do I have to collect data for each setup to tell which is better?
Is that even the right question? I'm
On 9 Oct, 2012, at 12:48 , Bob Camp li...@rtty.us wrote:
If you are after sub ns level timing, things are a bit different than if you
are happy with tens of ns error. Few of us have an adequate survey of our
location to *really* worry about sub ns numbers. If you are one of those
lucky few
Boy all I can say is I measured the $7 satellite splitter and it matched
the specs for fwd and rtn loss. Port to port loss using an HP network
analyzer. So what can I say it worked and well. Actually surprisingly so.
Regards
Paul.
On Tue, Oct 9, 2012 at 2:38 PM, Dennis Ferguson
Hi
In the context of the original post, probably the right question is: do you
have a hydrogen maser and an ensemble of cesiums to compare it to? That's
the environment that gets front and center at these conferences.
Bob
-Original Message-
From: time-nuts-boun...@febo.com
On Tue, Oct 9, 2012 at 10:33 AM, Hal Murray hmur...@megapathdsl.net wrote:
Suppose I wanted to do an experiment with GPS receivers: Is setup A better
than setup B? But they share some parts, say the antenna, so I can't run
them both at the same time.
How long do I have to collect data for
Here's a link to a USNO paper that measured the tempco of three GPS
amplifiers: http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA490830
They found that amplifier filtering was the prime cause of tempco, and
the narrowest bandpass amplifier they looked at had a group delay range
of 4 nanoseconds
Dear Edgardo,
On 10/09/2012 04:31 AM, Edgardo Molina wrote:
Now to the point if you kindly allow. I got involved in a round table
discussion around the use of GPS antennas for time and frequency GPS
receivers. I tried to make some points from my personal perspective.
I got resistance from the
On 10/09/2012 09:27 PM, John Ackermann N8UR wrote:
Here's a link to a USNO paper that measured the tempco of three GPS
amplifiers: http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA490830
They found that amplifier filtering was the prime cause of tempco, and
the narrowest bandpass amplifier they
albertson.ch...@gmail.com said:
The satellites are in 12 hour orbits. Everything repeats every 12 hours.
But the sun is on a 24 hr. period and if you did two 12 hour tests you don't
want to do one at night and one in day. So start each test at the same
time of day let it run for 12+ hours.
Dear Group,
Good evening. I just arrived home after the first day of conferences at the
Electrical Metrology Forum 2012 at Mexico's metrology center CENAM. I attended
several presentations of time and frequency, very interesting indeed. At last I
understood some concepts hard to land in
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