Hi George, welcome aboard. If you are a beginner about time and frequency
don't forget to get and read what was pointed out to be our introduction to
the subject http://gpstime.com/files/tow-time2011.pdf written by Tom Clark
and Rick Hambly.
On Wed, Mar 14, 2012 at 5:27 AM, Bill Hawkins
I forgot to add that the IF frequency used in the Austron 2201/2202 units is
75 MHz, and the Meinberg/Odetics is 35.42MHz, so they are not compatible
without additional conversion.
Rob
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of
Hi,
I'm currently writing a short article on crystal oscillators and am
looking for plots of typical phase noise and ADEV of an OCXO.
But unfortunately, i couldnt find any, so far. Only discrete numbers
from the data sheets, or phase noise plots only from scientific papers.
Does anyone have
I know that the Meinberg works with the old Odetics units, but the IF
frequencies are different on the Austron units.
Rob Kimberley
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of b...@lysator.liu.se
Sent: 14 March 2012 05:38
To:
On 3/14/2012 6:22 AM, Attila Kinali wrote:
Hi,
I'm currently writing a short article on crystal oscillators and am
looking for plots of typical phase noise and ADEV of an OCXO.
But unfortunately, i couldnt find any, so far. Only discrete numbers
from the data sheets, or phase noise plots only
And don't forget the usual PDF
http://gpstime.com/files/tow-time2011.pdfwhere you can find the
comparison of typical Allan Deviations from various
clocks on page 7.
On Wed, Mar 14, 2012 at 1:52 PM, John Ackermann N8UR j...@febo.com wrote:
On 3/14/2012 6:22 AM, Attila Kinali wrote:
Hi,
I'm
On Wed, 14 Mar 2012 08:52:14 -0400
John Ackermann N8UR j...@febo.com wrote:
Attila, TVB and I each have a bunch of plots of various oscillators at
our web sites. Tom's are mainly under http://www.leapsecond.com/pages
and http://www.leapsecond.com/museum; mine are under
On Wed, 14 Mar 2012 14:05:03 +0100
Azelio Boriani azelio.bori...@screen.it wrote:
And don't forget the usual PDF
http://gpstime.com/files/tow-time2011.pdfwhere you can find the
comparison of typical Allan Deviations from various
clocks on page 7.
That's for an other article :-)
This time, i
Programs that try to turn text into a link will get the URL wrong due
to a missing space. Fixed link:
http://gpstime.com/files/tow-time2011.pdf
On Wed, Mar 14, 2012 at 09:05, Azelio Boriani azelio.bori...@screen.it wrote:
And don't forget the usual PDF
On 3/14/12 6:23 AM, Attila Kinali wrote:
On Wed, 14 Mar 2012 14:05:03 +0100
Azelio Borianiazelio.bori...@screen.it wrote:
And don't forget the usual PDF
http://gpstime.com/files/tow-time2011.pdfwhere you can find the
comparison of typical Allan Deviations from various
clocks on page 7.
On 03/14/2012 11:22 AM, Attila Kinali wrote:
Hi,
I'm currently writing a short article on crystal oscillators and am
looking for plots of typical phase noise and ADEV of an OCXO.
But unfortunately, i couldnt find any, so far. Only discrete numbers
from the data sheets, or phase noise plots only
On Wed, 14 Mar 2012 06:42:34 -0700
Jim Lux jim...@earthlink.net wrote:
John Vig's presentation is a great place to start.. There's lots of
copies in various places on the web (IEEE UFFC site, for one)
Juup, that's where the idea for the article came from in the first place :-)
And yes, there
I joined the list at the suggestion of Bill, Wb6BNQ.
I am currently experimenting with several frequency standards, an Rb and an
OCXO. While I feel that I am able to measure frequencies with reasonable
accuracy, I have no way of accurately determining time, so have ordered a
T-Bolt. I expect
I understand the cartoon at the beginning; but, it will take me a very, very
long time to understand the concepts of the paper!
George
K2CM
Vestal, NY
From: Azelio Boriani azelio.bori...@screen.it
To: Discussion of precise time and frequency measurement
Hello all,
I purchased a FE5680A from a Chinese Ebay vendor. I have connected it to a
16.5V laptop supply, added 7805-based 5V rail and a PMOS Fet switch to drive
a LED for the locked signal. I can communicate with it using the excellent
Fe5680Calibrator software. As received the frequency
Good one George.
It is the obsessive compulsive time correcting disorder that we all have!
Raj
VU2ZAP
The big question is why am I doing this? Just because I can.
George
K2CM
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My fast approach would be to trigger a scope with the 1 PPS from the GPS
receiver and observe the how the 10 MHz output of your Rb drifts. 1
full cycle per second is 1 e-7 so you'll need to use an stopwatch to
time long periods when you are fine adjusting .
Building (or buying) a GPSDO allows
The first thing to consider is something to put the 5680 into. Search
the list for
temperature considerations. Basically you will need to heat sink the 5680. It
can be run without, but won't last long. The technique I'm going to
use it to heat
sink the 5680 and with a pair of small variable speed
Hi
Consider that the noise on the 10 MHz output of the FE5680 is pretty bad.
You may / may not want to propagate it all over your shop. At the very
least, a simple band pass filter is needed. A better solution would be to
lock a crystal oscillator up to the FE and use the output of the
Nice idea,
But I haven't got a DSO and the persistence of my scope isn't good enough to
view 10Mhz sampled at 1pps.
Chris
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of EB4APL
Sent: 14 March 2012 15:46
To: time-nuts@febo.com
Hi
Do you have a dual channel counter that you can put the GPS into on the
start and the FE into as the stop? The HP 5334, 5335, and 5345 are all
examples of this sort of counter.
Bob
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of
These pretty ADEV/Tau plots, do people have an automated
system to produce these things? How much work is involved?
How many samples are taken? Sample for a month, omputer crunching
for weeks?
I have no feel for what the process is like.
I have two oscillators and a Racal 1992 counter. If
may not be new to many, but to someone new on the list
http://www.ieee.li/pdf/viewgraphs/precision_frequency_generation.pdf
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On 3/14/2012 1:35 PM, Chris Howard wrote:
These pretty ADEV/Tau plots, do people have an automated
system to produce these things? How much work is involved?
How many samples are taken? Sample for a month, omputer crunching
for weeks?
I have no feel for what the process is like.
I have two
On 14/03/2012 18:36, Pete Lancashire wrote:
may not be new to many, but to someone new on the list
http://www.ieee.li/pdf/viewgraphs/precision_frequency_generation.pdf
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There's an interesting and more readable PRL by the same group,
published last year on June 2 . Its on arXiv: 1110.2379v1 . or PRL 106,
223001 (2011). They have already built the trap and have laser-cooled the
Thorium ions (cool pictures of the ion crystals). Their current problem is
Hi Bob,
Thanks for pointing-out the noisy output of the FE5680A. I'll probably try
to lock a crystal oscillator to it.
Unfortunately I don't have a suitable counter.
I was hoping I could use some sort of higher frequency standard but I
confess I had not really grasped the fact that the unit may
Here is a copy of the paper NIST co-authored describing the new WWVB phase
modulation format:
http://jks.com/wwvb.pdf (2MB PDF)
John Lowe from NIST said I could redistribute it to the list. It will be
available on the NIST website sometime in April once the official PTTI 2011
Has anybody looked at the impact of the periodic phase reversals of BPSK
on the loop of phase-tracking receivers, like the Fluke or the HP 117A?
NIST does claim backward compatability for time. But what about time
interval?
I know you can extract the carries from BPSK with a Costas Loop (which
Hi
At least the don't mess to much with it part has sunk in. That puts you ahead
of most people at this point.
A usable counter should be a sub $100 sort of thing either at auction or
surplus. With some careful shopping it can be a sub $40 item.
Bob
On Mar 14, 2012, at 4:25 PM, Chris Stake
Hi:
I sure would like a WWVB BPSK receiver for the new modulation. The processing gains described in the paper John Seamons
linked describes processing gains that are tens of dB above what's possible with the old AM data format. John has also
measures the experimental phase modulation
In message 4f6116ce.7080...@pacific.net, Brooke Clarke writes:
I sure would like a WWVB BPSK receiver for the new modulation.
I've been playing with SDR and VLF signals for ages. What you
want is an antenna, a 1MSPS ADC and a fast-ish CPU.
One very interesting thing you can do with that, is
The first move will be to familiarize with this new modulation format. Of
course I can't receive the WWVB but the DCF77 maybe a good test for me.
On Wed, Mar 14, 2012 at 11:08 PM, Brooke Clarke bro...@pacific.net wrote:
Hi:
I sure would like a WWVB BPSK receiver for the new modulation. The
Dear Time-Nuts,
(new at this list, but reading for long time excellent timekeeping
oscillator articles)
I sure would like a WWVB BPSK receiver for the new modulation. (..)
I'm sure in time there will be plenty of low cost ICs designed to receive the
new signal, but my guess is that many
All very nice, but if this change renders all existing receivers useless.
How does that improve things?
All it does is wipe out all the existing phase tracking infrastructure.
The only benefit is to the government who can reuse the WWVB transmitter
and frequency allocation. Everybody else will
On Wed, Mar 14, 2012 at 3:08 PM, Brooke Clarke bro...@pacific.net wrote:
Hi:
I sure would like a WWVB BPSK receiver for the new modulation. The
processing gains described in the paper John Seamons linked describes
processing gains that are tens of dB above what's possible with the old AM
There seems to be a strong likelihood that the 2201 is compatable with the
mienburg. Thats what I believe Doug actually has. If there some detailed
info in your link I will take a look.
On Wed, Mar 14, 2012 at 1:38 AM, b...@lysator.liu.se wrote:
Paul,
Thanks to Doug above I am trying two
Asus has a $30 Xonar PCI soundcard that should do the job.
I have two of the the more expensive pci-e versions. Some motherboards
can do a/d at 192 but not as well as the Xonar.
I made a 60 KHz antenna by winding a zillion turns on a ferrite
rod and a padder going into the gate of a FET.
OK the updates.
The issue is the 2201 is a 75.42 Mhz IF and most of these alternates are
35.42. Hmmm sounds like adding 40 Mhz gets you the answer.
Thats exactly what I did with the odetics converter from Pete L.
Took 10 Mhz from 2201 4 X to 40 mix with 35.42 buffer and send to the 2201.
Locks
I will share my few bits of worked experience. But it may seem obvious.
I'd say to go 100% SDR. In other words a simple front and that
pushes as much of the functionality into software as possible. The
carrier is only 60K. That is low enough that one can directly
digitize the RF using an
On Wed, Mar 14, 2012 at 8:17 AM, Chris Stake st...@btinternet.com wrote:
Hello all,
I purchased a FE5680A from a Chinese Ebay vendor. I have connected it to a
16.5V laptop supply, added 7805-based 5V rail and a PMOS Fet switch to drive
a LED for the locked signal. I can communicate with it
In message Pine.LNX.4.64.1203142345310.2459@tesla, Marek Peca writes:
I will share my few bits of worked experience. But it may seem obvious.
I'd say to go 100% SDR. In other words a simple front and that
pushes as much of the functionality into software as possible. The
carrier is only
If neutrinos can have mass, then I guess neutrons can have orbits. But
what do I know? It's all Greek (letters) to me :-)
Joe Gray
W5JG
If you google nuclear shell model you'll find a good Wikipedia
article on the nuclear energy levels. Oddly enough, there is a similarity
between the
I picked up a gimpy Beckman UC10 universal counter not long ago for
about $10 from Ebay. Even better, I just repaired a Tektronix 7D15
(it has a whole board full of those junk TI integrated circuit sockets
which need to be replaced) although you need to leave an entire
oscilloscope mainframe on
Hi John:
They are going to maintain the existing AM modulation format so all the WWVB Atomic Clocks will still work. The phase
modulation is added on top of that.
Yes, I expect my HP 117 may no longer work, but I'd much rather have the
improved s/n and timing accuracy.
Have Fun,
Brooke
Brooke,
As I've said, I don't care about the Time. The time determined by the
start of TV or radio programs is plenty good enough to keep any
appointments.
My only interest is as a standard of Time Interval as a reference for
synthesizers, counters, etc.
If you think about it, unless you are
Hi!
I'm looking for a sampled wave-file from a radio receiver MPX-signal
including the RDS frequency band around 57KHz. I searched the Net but
found just nothing that worked.
So I ask here. Maybe someone has the possibility to sample a couple of
seconds.
Thank you all!
- Henry
--
I am afraid that like John my concern is the frequency reference. Time?
Heck it comes by the internet, WWV or GPS and lastly good old watches that
do pretty well these days. No comments on celphones. So the term is
screwed. All of the sampling and computer processing may indeed loose the
primary
Brooke,
In speaking with John Lowe of NIST (Group Leader for Time Frequency service),
he stated that the absolute time recovery of
their intended new modulation scheme is 10 milliseconds. Nothing stellar there
!
BUT you are right, all of us that have hp-117 type receivers are just out of
OK thats great a maybe pic chip answer. They do cure all ill's after all.
Really scratching my head here. But I do think there is an answer as long
as the phase reversal is accurately controlled and still referenced to the
reference standard.
A I say I need to read.
Regards
Paul
On Wed, Mar 14,
In thinking about it a bit further, one might be able to take the 60 kHz
received sine at some point in the receiver, full wave rectify and HP
filter it (which doubles the frequency) then divide by two in a Flip-Flop
and heavily filter the resultant. This is a hybrid solution... analog and
I guess that will mean that my bullet proof Tracor 599J will become a paper
weight. I have a couple of units that were surplussed years ago from the
USNO. Great receivers.
Sam
W3OHM
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John
Like your thought. I seem to remember costas loops work like that to
recover the carrier.
Paul,
It recovers a bipolar signal to steer the local VCO as well as the data..
It also needs a quadratue hybrid at the VCO frequency (although it might
be fairly easy to make a quadrature
On 3/14/12 8:07 PM, J. Forster wrote:
John
Like your thought. I seem to remember costas loops work like that to
recover the carrier.
Paul,
It recovers a bipolar signal to steer the local VCO as well as the data..
It also needs a quadratue hybrid at the VCO frequency (although it might
be
I know I am not one of the good-ole-boys here but I'd say go 100% SDR with
your PC without an external
A/D converter. Ok, how would you do this? You use under sampling.
Many A/D converter systems use a sample and hold before the A/D converter.
If you do the same before your sound card (your
On 3/14/12 8:07 PM, J. Forster wrote:
John
Like your thought. I seem to remember costas loops work like that to
recover the carrier.
Paul,
It recovers a bipolar signal to steer the local VCO as well as the
data..
It also needs a quadratue hybrid at the VCO frequency (although it might
Bill wrote:
[BPSK] leaves all the real Timenut type people, actually
using the system for its intended purpose, out in the cold
To be fair to NIST, there really aren't many people using WWVB as a
source of laboratory-grade timing signals. As others have pointed
out, it isn't accurate
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