In the past few months, we have had lots of issues with private emails going to
the whole list. Especially AOL. One of these days, it could get really
embarrassing. Can't figure it out, yet. Meanwhile, please double check what you
post to/cc/from.
/tvb (i5s)
On Dec 10, 2014, at 11:37 AM,
Pete, Paul,
You can always try increasing the Cs oven temperature. I'm told +10 C will
double the beam current -- and half the life. But my my, hey hey sometimes it's
better to burn out than fade away.
/tvb (i5s)
On Dec 6, 2014, at 5:25 PM, Pete Lancashire p...@petelancashire.com wrote:
If you manipulate the buy number he as 19 left.
If you manipulate the number all you know is that there are 19 left in the
current eBay lot.
If you talk to the seller you'll find he has hundred(s) and perhaps the eBay
stock quantity is updated as needed.
To test this, please record the buy
Paul,
Large plots are ok. They just get flagged by the server for approval.
/tvb (i5s)
On Nov 11, 2014, at 8:03 PM, paul swed paulsw...@gmail.com wrote:
I was thinking about snapping a pix. Though it has to be pretty small to
get through time-nuts.
Clearly my units still aging/adjusting
Thanks, that was the final link I hope someone would post. I have many more
links, but this is not the right forum for that.
Now, everyone - STOP posting FTDI information to time-nuts.
We are a precise time frequency list.
If you want to discuss FTDI or Windows driver issues please subscribe
Hi Stephane,
Welcome. There's nothing wrong on your end. Thanks for asking.
Subscription to this list is open to all without approval. Since about a year
or two ago postings from new subscribers are moderated. Any technically rich,
on-topic posting goes through.
/tvb (i5s)
On Sep 15, 2014,
Some OCXO schematics:
http://leapsecond.com/museum/10544/
http://leapsecond.com/museum/10811a/
/tvb (i5s)
On Sep 5, 2014, at 5:50 AM, Dan Kemppainen d...@irtelemetrics.com wrote:
Hi Bob,
Being relatively new to this 'high end' time stuff, there's lots to
learn... So, how much bandwidth
Hal, as long as you maintain long-term phase lock it's a disciplined
oscillator. So, yes, a carrier tracking WWVB receiver with sufficiently stable
flywheel LO is a WWVBDO.
Said, too-short or too-long 100 ns cycles is one thing. Still ok for many
applications. But tell me more about extra or
Paul,
Your expectation works for text attachments. But binary attachments (e.g., jpg)
expand about 33%. That's 8/6, or log2(256)/log2(64), due to base64 encoding of
8-bit bytes.
In general, large attachments on this list are ok. It's just that when they are
above 128k they are temporarily
This is a precise time frequency list. Please explain a little more how your
battery question relates?
I've actually spent a lot of time over the years working on fail-safe power
issues. It's actually really hard! But, what's your goal, or specifications, or
specific problem?
/tvb (i5s)
On
http://tf.boulder.nist.gov/general/pdf/2719.pdf
/tvb (i5s)
On May 31, 2014, at 1:03 AM, David I. Emery d...@dieconsulting.com wrote:
Well the actual details of the WWVB modulation and time
codes are now published.
Was just leafing through some journals while doing some
boring
Check rising/falling edge times, check trigger levels, check signal levels and
load. Are you DC or AC coupled. How about power supply noise and grounding?
Which edge are you actually triggering on? Is there crosstalk with the Tx line.
It is extremely unlikely that there's a problem with the UT+
To keep Tom happy please reply off list.
bro...@pacific.net
That's correct.
If you find yourself typing OT or WOT in the subject line, that's a clue to
stop right there.
/tvb
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On May 18, 2014, at 3:14 PM, Chris Albertson albertson.ch...@gmail.com
wrote:
I think(?) it is really a value from 0 to 255 and you must apply a
Chris,
The manual clearly states -128 to +127. What's your problem with that?
/tvb
___
time-nuts
Hal,
Yes, there are negative delays. The goal is that the physical 1PPS output is,
on average, exactly on-time. If designed right, that means as many negative
offset pulses occur as positive offset pulses. The spread gives you the RMS
value.
This is exactly what you want for a GPS timing
-128 is 0x80
+127 is 0x7F
If in doubt, just look at the sawtooth correction messages coming out of your
M12.
/tvb (i5s)
On May 18, 2014, at 4:17 PM, Chris Albertson albertson.ch...@gmail.com wrote:
Chris,
The manual clearly states -128 to +127. What's your problem with that?
Yes it
Tony, Chris, Bert,
Since all you want is a 10 ns time stamp / data logger you do not need a GPSDO,
or OCXO, or VCXO.
The solution is cheap and very simple.
Your GPS receiver provides a 1PPS to the microprocessor. Use a plain XO or
TCXO; the frequency does not need to be accurate, just stable
Besides the header and trailer you need to unescape any embedded DLE's in the
data stream.
/tvb (i5s)
On Mar 25, 2014, at 2:43 PM, d0ct0r t...@patoka.org wrote:
Today I spent good part of my time to figure out that my version of
Thunderbolt has some issue with the TSIP protocol
Rule of thumb:
- really good OCXO have frequency drift rates of 1e-10 to 1e-11/day
- common Rb have frequency drift rates on the order of 1e-11/month
- Cs do not have frequency drift
- H-maser drift rates are 1e-15 to 1e-16/day
/tvb (i5s)
On Mar 23, 2014, at 4:32 PM, Charles Steinmetz
Do you have a photo? I have a large collection of hp oscillators here and do
not see a 10544 with SMB. Are you sure it's not 10811?
Then again, there are 10544A s/n 1528Ax mounted on a 15-pin PCB
(05238-20027) which has a SMB connector.
/tvb (i5s)
On Mar 13, 2014, at 12:44 PM, Mark
The safe URL, without Joe's encrypted personal information, is:
http://tf.nist.gov/general/pdf/1969.pdf
/tvb (i5s)
On Feb 21, 2014, at 1:38 PM, Joe Leikhim jleik...@leikhim.com wrote:
Brooke,
See old posting:
http://www.febo.com/pipermail/time-nuts/2011-January/053478.html
The effect is too small (~5e-17 over 6 hours) to affect GPS time transfer.
/tvb
On Feb 19, 2014, at 8:24 AM, Brooke Clarke bro...@pacific.net wrote:
Hi:
In the video about the Full Moon Curse
TomK,
If anyone has technical contacts deep within Agilent, let's see if this issue
can be resolved. I would have bought a 53230A when it came out a few years ago
but my eval units showed this clock noise problem. That plus the poor quality
of the ref out made me think the designers were
Bob,
I'm wondering if you (or any else) has measured the PLL performance of the
53230-series?
I agree it will clean up the crud but this assumes the ext ref is dirtier
than the internal osc.
What I found instead was that if you use a good external ref the PLL actually
makes it worse. This
Thanks Brooke, nice link. I've always enjoyed the work that Murphy does.
The technical article is here:
http://arxiv.org/pdf/1309.6274.pdf
Years ago I got to see a laser ranging telescope at a NASA site. Talk about
green flash. Truly amazing. I remember at the heart of it was... a 5370 counter!
http://www.leapsecond.com/pages/m12/sawtooth.htm
/tvb (i5s)
On Feb 16, 2014, at 4:46 PM, Bob Stewart b...@evoria.net wrote:
The smart guys have already contributed to this thread. What I have is an
example taken when I was doing some testing. The plot at the top is the DAC
on my GDPSO.
Tim,
Perhaps a watchmaster G47? Very clever device, and yes, a fine mechanical
example of a phase comparator. Google for it and see sites like:
http://myplace.frontier.com/~dritland/watchmaster/
/tvb (i5s)
On Feb 10, 2014, at 12:01 PM, Tim Shoppa tsho...@gmail.com wrote:
IIRC some watch
Hi Simon,
1) You can use the picPET to measure zero crossings; just bias the input.
2) With no external parts at all the picPET is a 2.5V crossing detector.
3) What you find when you start playing with 60 Hz is that this is not a
problem. That's why few/none of us bother with it.
4) The time of
It depends of your goals. If you want a 60 Hz time/frequency standard then
using a mains disciplined oscillator is good. Like AN12 shows.
But if your goal is to measure mains itself, warts and all, then measure mains
as it is, not a pure oscillator tied to mains by PLL or FLL.
See this Atmel
As much as I'm fond of my picPET it has 400 ns resolution and not intended to
replace a 5 or 10 or 50 ns TIC (which is what the OP asked for).
/tvb (i5s)
On Jan 22, 2014, at 5:12 PM, Robert Atkinson robert8...@yahoo.co.uk wrote:
Hi,
For a low cost startup have a look at a picPET
projects that get a greater resolution? I was
thinking of doing something with a dsPIC33 running at 140MHz or greater, but
I'm not sure I want to devote the time to if it's it's been done.
Bob
From: Tom Van Baak (lab) t...@leapsecond.com
To: Robert
VCR's were well known to reliably read 12:00 throughout the year...
Do you want to make or buy? Using a microprocessor, it's easy to drive a
stepper-motor based wall clock at slight offsets from true 32 kHz or 1 Hz rate.
Converting UTC/1PPS to solar rate and time for your given location and
Hi Paul,
About cesium clocks: hp 5060A and early versions of the hp 5061A needed to be
able to keep *either* atomic time (true, accurate, stable, SI seconds) or
astronomical time (inaccurate, unstable, slow, and gradually slowing, earth
rotation time).
The larger C-field range allowed this
Lots of info, including manual and schematic if you google: sulzer frequency
standard
/tvb (i5s)
On Dec 13, 2013, at 5:41 AM, oe1lpw oe1...@telekabel.at wrote:
Dear Sirs,
I got a Sulzer Frequency Standard 2,5 B (?) and I`m looking for a manual or
handbook. The standard has the filter
Brooke,
Not sure what you find in error; please explain.
I have all the Shortt info you need. Not all of it is for Wikipedia; contact me
off-line.
Just got back from the CalTech
Time Symposium:
http://leapsecond.com/nawcc2013/
The conjecture about tides is explained in great detail here:
Try averaging for about 86160 seconds instead of 86400 seconds.
See: http://spot.colorado.edu/~kristine/gpsrep.pdf
/tvb
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Doc,
I measure mains time frequency with a picPET all the time. In fact that's one
of the reasons I designed it. If you're having any trouble contact me by email.
/tvb (i5s)
On Nov 16, 2013, at 11:23 AM, Bill Dailey docdai...@gmail.com wrote:
My purpose is to do it with a picpet. That's
Some nice ones here -- google for: cesium beam tube
/tvb (iPhone)
On Sep 24, 2013, at 9:40 AM, Tom Miller tmil...@skylinenet.net wrote:
Sure be nice if you could put them up on some photo site and let us see them.
- Original Message - From: ewkehren ewkeh...@aol.com
To:
All NIST papers are available for free. Makes you happy to be a taxpayer. The
one you're talking about is at:
http://tf.boulder.nist.gov/general/pdf/2688.pdf
/tvb (iPhone4)
On Aug 23, 2013, at 3:03 PM, John Miles j...@miles.io wrote:
Don't you just love paying to access research that your
Any of the PC (native serial or USB/serial adapter) modem control lines can be
used to get a positive or negative voltage. In your case look at pin 7.
See comments at the end of http://leapsecond.com/tools/comtick.c
/tvb
Sent from my iPad/mini
On Jul 26, 2013, at 4:01 AM, ewkeh...@aol.com
It's mathematical in both frequency, and in phase (clock and channel input
timing). Depending on relative cable lengths I suspect you can get lucky and
see it always wander 1 count above 5 MHz instead of 1 count below 5 MHz. But
you should not expect it to do both; that would be 2 counts; your
Ok, thanks for clarifying. In general the time constant one chooses must
reflect both the intrinsic performance of the OCXO (essentially constant) and
the realities of GPSDO mechanical, sky-view, and environmental conditions
(possibly variable). Disabling an oven during a run is equivalent to a
Rule of thumb: quartz is best short term, Rb or H-maser mid-term, and Cs by far
the best long-term.
For GPS clocks the long-term doesn't matter that much since each space clock is
monitored and updated against the GPS master clock(s) on the ground.
/tvb (iPhone4)
On May 4, 2013, at 11:40 AM,
Note also Galileo uses Rb and H-maser only; no Cs.
/tvb (iPhone4)
On May 4, 2013, at 1:53 PM, Poul-Henning Kamp p...@phk.freebsd.dk wrote:
In message bb05041d-f03a-42ac-85c6-467110fc3...@leapsecond.com, Tom Van
Baak
(lab) writes:
Rule of thumb: quartz is best short term, Rb or H-maser
See if this helps:
http://www.leapsecond.com/museum/au2100f/scope.htm
/tvb (iPhone4)
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Yes, correct, sometimes the power line goes faster than 60 Hz in which case the
zero-crossings occur before you expect them; so time error can be negative,
on average, as often as it is positive.
You cannot design a PLL that always expects phase error to be unidirectional.
The data I provided
Paul,
I use a picPET (http://leapsecond.com/pic/) to measure heart rate and
stability; the original 1PPS... The idea is simply to time-stamp every beat
and then convert that raw data to rate or period or moving average rate, etc.
/tvb (iPhone4) LA
On Feb 19, 2013, at 4:58 PM, Paul Cianciolo
On Feb 19, 2013, at 5:38 PM, Hal Murray hmur...@megapathdsl.net wrote:
pa...@snet.net said:
The actual electrodes instrumentation amp is pretty much working fine so no
worries there.
My first tthought was a frequency to voltage IC like the LM2907 or the 2917
but I get the impresiion
I often plot both ADEV and MDEV, too. The difference between them indicates the
amount of white phase noise there is in the measurement (the sum of DUT and REF
and phase meter). You'll see for some standards, especially at longer tau,
there is little or no difference.
Right, MDEV is almost
Yes, Don, those old quartz bars are rare and amazing:
http://leapsecond.com/museum/gr676b-50kc/
http://leapsecond.com/museum/gr1190a/
The inside joke is that recently Don gave me a new one, also GenRad, that I
hope to photograph and measure soon.
Thanks,
/tvb (iPhone4)
On Jan 22, 2013, at
Norm,
No cross-posting on this list, please. Your email has nothing to do with
time/frequency.
/tvb (iPhone4)
On Dec 14, 2012, at 10:25 AM, Lizeth Norman normanliz...@gmail.com wrote:
Hi all!
My 48gx is up for sale. Included are the following items
db-9 to calculator cable
soft case with
Easiest way is to use google with site:febo.com as one of the search words. For
example, if one were interested in an old FTS 4050 cesium clock google for:
site:febo.com fts 4050
/tvb (iPhone4)
On Dec 8, 2012, at 8:24 AM, Mike Garvey r3m...@verizon.net wrote:
Is there a way to search the
Bob, Charles, Chris,
If the goal is a GPS locked frequency counter then there is no need for
disciplining the LO at all. Just let the XO or OCXO or Rb free-run. Use a two
channel counter: one capture input to measure the frequency of the DUT and
another capture input to leisurely and
http://www.leapsecond.com/museum/hp5065a/conn.htm
/tvb (iPhone4)
On Nov 24, 2012, at 4:50 PM, Pete Lancashire p...@petelancashire.com wrote:
What is the MS type for the power plug for a 5061A ?
I could not find it in the PDF I have.
-pete
Chuck,
Information about the HP submarine cesium standard (5062c) as well as details
about Zeeman splitting are here:
http://www.leapsecond.com/museum/hp5062c/theory.htm
/tvb (iPhone4)
On Oct 28, 2012, at 1:25 AM, Chuck Harris cfhar...@erols.com wrote:
Magnus Danielson wrote:
On 10/28/2012
Cs tube ADEV is related to S/N ratio which is dependent on beam flux (the
formula is in any quantum physics textbook).To achieve higher beam currents
high-perf tubes run the oven at a higher temp (which is why their lifetime is
much shorter).
So yes the RF chain is the same. But the oven
I'll send you a known working 10368A.
/tvb (iPhone4)
On Oct 28, 2012, at 1:36 PM, John Ackermann N8UR j...@febo.com wrote:
Thanks to all for the helpful replies.
At this point, I believe what happened is that the degausser isn't working
properly and that may have resulted in the tube
http://leapsecond.com/museum/osa8607/
/tvb (iPhone4)
On Sep 19, 2012, at 11:16 AM, Ron Ward n6idl...@comcast.net wrote:
Thanks John:
WOW, I didn't realize that some oscillators are now at 7X10-14.
Thanks,
Ron
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Hi Paul,
See http://leapsecond.com/pic/picpet.htm and contact me offline for the USB
part.
What do you use for sensors: acoustic, optical, seismic?
/tvb (iPhone4)
On Aug 26, 2012, at 10:48 PM, Paul Cianciolo pa...@snet.net wrote:
Hello Folks
I have been looking at bullet chrographs and
Schematics for all versions of the 10509A antenna:
http://www.leapsecond.com/museum/10509a/
/tvb (iPhone4)
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Chris,
The HP 5065A is one of the best Rb ever made.
/tvb (iPhone4)
On Jul 1, 2012, at 21:12, Chris Albertson albertson.ch...@gmail.com wrote:
On Sun, Jul 1, 2012 at 8:39 AM, Edgardo Molina xe1...@amsat.org wrote:
Dear Chris,
One of my needs: A dependable Rb source. HP appeals to me as
Leap second countdown clock:
http://www.leapsecond.com/java/nixie.htm
It should work on any browser or smartphone.
/tvb
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There's an old list of how to (and how not to) watch a leap second:
http://leapsecond.com/notes/leap-watch.htm
The NMEA output of some GPS receivers is fun to watch. Some use a double :59:59
or double :00:00 instead of :59:60 for a positive leap second.
/tvb (iPhone4)
On Jun 29, 2012, at
Someone asked about the short ADEV tutorial I wrote a few years ago. The text
and graphs are at:
www.leapsecond.com/pages/adev/
/tvb (iPhone4)
On Jun 26, 2012, at 14:32, Tom Van Baak (lab) t...@leapsecond.com wrote:
With four points one can compute ADEV...
photo.JPG
I'm very south of the equator on a family vacation right now, away from my lab,
remote enough to miss the upcoming leap second. But here's a photo of a sundial
I made with driftwood and shell markers every 5 minutes.
inline: photo.JPG
/tvb
With four points one can compute ADEV...
inline: photo.JPG
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In my haste to post I forgot to delete the 00:00:00 UTC string from that
list. The rollovers happen at 00:00:00 GPS time, which differs from UTC by a
number of seconds.
/tvb (iPhone4)
On Jun 7, 2012, at 12:53 PM, Tom Van Baak t...@leapsecond.com wrote:
GPS week number roll-overs happen
Google for: high rate gps seismology
You will find many wonderful papers that describe this new field.
Start with: http://www.colorado.edu/engineering/GPS/Larson_Seismology2009.pdf
/tvb (iPhone4)
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To
Marvin ,
Sounds like you're making great progress on a nanosecond timing system.
Question: what are you doing with the Novatel data? Is it used to error correct
later on or are you using it to steer in near real time?
Answer: on the 5071A serial port; I issue a SYST:PRINT? command every 5
Could be on the electrical side of the adapter, not the optical side. It's not
impossible to get 60 ns of phase or trigger error with RF connectors.
/tvb (iPhone4)
On Feb 22, 2012, at 12:41 PM, Marco IK1ODO ik1...@spin-it.com wrote:
Well, timenuts friends, how may a fiberoptic bad connection
Examples of GPSDO, rise time, impedance and trigger level:
http://www.leapsecond.com/pages/gpsdo-rise/
/tvb (iPhone4)
On Feb 22, 2012, at 2:26 PM, Poul-Henning Kamp p...@phk.freebsd.dk wrote:
In message 9a458dba-3875-43b2-8383-5ca2f86be...@leapsecond.com, Tom Van
Baak
(lab) writes
I was wondering how one would even use a PIC.
You can make a 10MHz to 1PPS divider using a tiny 8-pin PIC. I have extras
here. Send me email off-line if you want one. Cost is $2.
/tvb
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Antonio, and other posters,
The issue of leap seconds is covered in the LEAPSECS mailing list rather than
time-nuts.
You can find the archives at:
http://six.pairlist.net/mailman/listinfo/leapsecs
Please move your well thought out questions or comments to that list.
Thanks,
/tvb
1E14 we might be able to notice
Hal,
No. Look at the adev of the earth (earlier posting). The length of earth day
varies in the *milli*second range, day to day. VLBI measurements are under 0.1
millisecond, which comes to about 1e-9 resolution.
Realize that none of the NASA earthquake may
Absolutely, but you can still pull a new Cs out of the box and it will
run at the same frequency as your old Cs.
Not quite the same. This is called the re-trace spec which is poorer than the
stability spec. Vintage Cs standards like the 5060 or 5061 powered up within
about 1e-10 or 1e-11. The
A primary frequency standard is one that faithfully implements the definition
of the SI second. Thus primary standards are based on Cs. But not all Cs-based
clocks are primary. CSAC, for example, is not a primary standard. Rubidium,
hydrogen, quartz, or pendulum clocks are not primary.
The
I've been told the NERC has decided to postpone their July 14 TEC-elimination
test.
Sorry I don't have a URL with more information.
Those of you logging 60 Hz data should continue.
As you know from my web site, measuring any sort of time/freq source is
interesting.
If nothing else you will have
Mark,
If the planet were not inclined 23 degrees this might make sense. But it turns
out daylight times differ by latitude and season and hemisphere. So it is not
surprising that nations, or even states within large nations, assume the right
to set their own rules of local time.
/tvb
On Jul
So what is the Allan deviation of the earth spinning? :)
http://www.leapsecond.com/museum/earth/
/tvb
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