Re: [time-nuts] Zero dead time and average frequency estimation

Magnus, Correct, all the terms cancel between the end points. Note that this is exactly equivalent to the way a traditional gated frequency counter works -- you open the gate, wait some sample period (maybe 1, 10, or 100 seconds) and then close the gate. In this scenario it's clear that all the p

Re: [time-nuts] Zero dead time and average frequency estimation

Magnus, I see there are other versions of the Rubiola paper:

[time-nuts] The Smell of Tantalum in the Morning

I powered up a 5071A to watch the end of Loran-C today and was greeted by the special smell that only a mother board could love. Does anyone know the history of tantalum capacitor failures in ten-year old [HP/Agilent] test equipment? This is not my first. Last one was more like July 4th. Thanks,

Re: [time-nuts] Tight PLL Tester

If there are any Nuts out there interested in helping to make available to other Freq-Nuts a SIMPLE tester that I have found to be a VERY useful low cost tool, Warren, Yes, I think it's a good idea for a couple of people to try to duplicate your results; either to validate the resolution and f

Re: [time-nuts] nubie querie

I`m not sure that questions like these is welcome on this list, but here goes anyway : 1/ What are the the 10 sources of the most constant [invariant] frequencies known to man, in order of decreacing constancy? Four immediately come to mind. 2/ What is the mechanism in an oscillator, that is

Re: [time-nuts] nubie querie

In the last slide you show a sand timer. Do you have accuracy data for it? Hi Brooke, The past 3 hours the "one hour" timer measures 56:24, 56:19, and 56:30. That's at 67 F room temp. Somewhere I have enough clean data to compute the ADEV; it's more stable than accurate. It also has a tempco

Re: [time-nuts] nubie querie

I vaguely remember reading that pulsars have some fantastic stability like 1E-20. I don't remember how they established this. Rick, See: http://www.leapsecond.com/museum/pulsar for some pulsar ADEV stability plots and links to many research papers with all the details. /tvb

Re: [time-nuts] nubie querie

Even defining when the sand timer is "done" is not a real simple thing. Waiting for that very last particle to drop may not be the best approach. Bob Correct. Marking time with an hour glass is not that different from marking time with a 1PPS. Each signal has a rise time; one picks the approp

Re: [time-nuts] nubie querie

Not to kick sand in your face, but it seems that in order for your automated turn-over device to work, as well as to accurately measure the time intervals, you would need a means to determine when the sand quits flowing. Correct. It's not unlike a zero crossing detector. The period of the sand f

Re: [time-nuts] Azimuth/elevation dependent satellite masking

I played around some with masking sats that were in poor signal areas, but the problem I wound up with is once you exclude a sat the Tbolt firmware no longer tracks its position so you don't know when its safe to start using it again.To determine that properly you would need to model the sat

Re: [time-nuts] Do you have HP5065A units for sale? If so, please contact me directly. Thanks!

You might consider the Stanford Research PRS10. Ruifeng is specifically looking for hp 5065A. For a certain mid-range of tau there nothing sort of a maser that beats a well-working 5065A; "they don't make 'em like they used to". As others have pointed out none of the telecom rubidiums come close

Re: [time-nuts] Schematic and BOM

David, Did you see the TAPR TADD board(s) before you started your divider project? I'm curious what features (or missing features) led you to your board design. Thanks, /tvb ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https

Re: [time-nuts] Austron 2110 B

I wonder if some one might have an idea of what might be happening with my 2110 B? Check all the DC power supply voltages and ripple/noise. If that doesn't help, I'll dig out my 2110B and manual and have a look for you. /tvb ___ time-nuts mailing li

Re: [time-nuts] Schematic and BOM

Last time I used a 5370B and a SR620. This time I'd like to try a Wavecrest. If someone on the list has done this already can you let me know? Thanks, /tvb - Original Message - From: "David C. Partridge" To: "'Tom Van Baak'" ; "'Discussion

Re: [time-nuts] Divider pecking order ?

Group, If Dave P's current divider design has design jitter specs approaching SOTA vvs cost levels whilst the TAPR board is (perhaps) slightly inferior in performance, where does that leave Tom's venerable 1pps PIC divider in the pecking order ? Will all designs be subjected to a "back-to-back"

Re: [time-nuts] Divider pecking order ?

The TSC5120A allows phase noise measurements on signals with frequencies down to 1MHz. Classical diode mixer based systems can go somewhat lower in frequency. You should realize that I have reasons to believe that the limit is one of software parameters rather than anything else. Lacking a TSC

Re: [time-nuts] GPS antenna setup: how good?

Hal, That's a really good question and if anyone can point me to carefully performed measurements already done, I'd appreciate it. It could be antenna A vs. antenna B, or it could be antenna A with vs. w/o ground plane, or choke ring, or radome, or temperature stabilization, etc. For short-term

Re: [time-nuts] Making a HP 10811 better

I have not had problems with My G changing short term, (BUT it would be interesting to see if I can detect the moon overhead). Warren, Lunar/solar tides change g at roughly the 1e-7 level over an interval of 6 to 12 hours. The g sensitivity of a 10811 is on the order of 1e-9. So the quartz osci

Re: [time-nuts] Making a HP 10811 better

Warren, No, measuring an oscillator every second will not help. The change in g = ~9.81 m/s due to tides is about 1e-7 over part of a day. So g changes by about 1e-8 per hour; that's about 1e-12 per second. Now df/dg for a 10811 is on the order of 1e-9. So the tidal effect of the sun/moon will

Re: [time-nuts] TBolt: UTC PPS

It also has an option to sync the PPS with GPS or UTC. I thought they were off by an integral number of seconds so I don't expect any change. Does anybody know what's going on here? The GPS broadcast message includes leap second and a0 and a1 terms which are used to forward predict UTC from G

Re: [time-nuts] TBolt: UTC PPS

So yes, at the ns level the two 1PPS will differ since UTC is not the same as UTC(USNO) or any other UTC(k) for that matter. Have you measured it? I would be interested to know what the delta is for your receiver today. You can also dump out the a1 and a0 corrections with binary commands on some G

Re: [time-nuts] TBolt: UTC PPS

I was close to typing in the same stuff. I got: -9.31323e-10 -5.32907e-15 In that packet, a0 is double precision. Does anybody know why they need all those bits? Hal, Referring to the GPS ICD, the size of A0 in subframe 4 is a signed scaled 32 bit integer so if a receiver chooses to conver

Re: [time-nuts] TBolt: UTC PPS

I suspect that generating some sort of 60 Hz sine-ish wave would open up the selection of clocks considerably. Bob Correct. See: http://leapsecond.com/pages/atomic-nixie/ /tvb ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to

Re: [time-nuts] What time is it anyway?

Below is a nice description of how UTC is generated including a chart showing how individual timing laboratories, BIPM and IERS are connected: /tvb ___ time-

Re: [time-nuts] TBolt: UTC PPS

Hal, The words "insert a pulse" is what causes the confusion in conjunction with leap seconds. There is no extra or missing pulse; no double pulse, no early or delayed pulse. The 1PPS output continues to give a pulse at a 1 Hz rate regardless if there is leap second or not. There is never any am

Re: [time-nuts] Making a HP 10811 better

Now if you really want some fun connect your OCXO to a one meter cable and let it swing like a pendulum clock. You should see some very nice sinusoidal FM as it goes back and forth. Devise some sort of mechanical, compressed air, or magnetic impulse system to keep it running like that all day. /t

Re: [time-nuts] TBolt: UTC PPS

Use a JK flip flop to divide by 2. During insertion of the leapsecond take J+K to zero to disable toggling of the FF. To delete leap second you could try inserting an extra clock pulse halfway between a apair of seconds ticks. If the clock cant cope with the above scheme you may need to use a

[time-nuts] New Most Accurate Clock

I used the new google today and found that a new type of atomic clock has been developed which promises a revolution in timekeeping. Typically national physics laboratories, such as NIST in the United States, develop the most precise atomic clocks. But today the best clock comes from NUTS, a qu

Re: [time-nuts] Thunderbolt Group Buy, part 3 - Thunderbolt quits

I've been having a chronic problem with one of the TAPR Thunderbolts that I bought; it just stops communicating. I have to power it down and back on to talk to it. I've not heard of this before. Sounds interesting. Perhaps someone will have a suggestion. But otherwise, I'll will be happy to take

Re: [time-nuts] Simulating Oscillator Noise: Difficulties SimulatingFlicker FM Noise

Hi Kyle, I looked into this a while ago and just ended up using the random clock data generators within Stable32. But if you end up with a code snippet for flicker noise let us know. You'll find a wealth of ADEV information at Bill Riley's site. http://www.stable32.com and http://www.wriley.com

Re: [time-nuts] Frequency Stability of An Individual Oscillator:Negative Values?

Kyle, Right, when working with 3-cornered hats, negatives show up now and then, especially if your adev calculations are based on tens or hundreds of points instead of thousands or tens of thousands. Or if the runs are made with different equipment or in different environments. Also, I remember t

Re: [time-nuts] synchronizing a large number ofweaklycoupled oscillators

Hi If the oscillators all lock to each other, then multiple oscillators don't have any particular advantage. Let's assume you can isolate them so they don't lock to each other. If they are all of similar construction in a similar environment, there is a very real limit to the advantage you wou

Re: [time-nuts] TPLL secret reveled

Fact #1) the TPLL uses Freq not phase, Warren, can you please clarify. From what I can see it actually uses a Minicircuits phase detector, right? That suggests what is being observed is a phase difference between the DUT and the REF, not a frequency difference. That analog phase measurement is

Re: [time-nuts] TPLL secret reveled

Where does the "1e-15" figure come from? Is that phase and are the units seconds or radians? Or is that relative frequency at the mixer, if so over what tau does it refer to? I'm curious how you measured or calculated the 1e-15 number. Saying "very nearly zero" doesn't mean much to me. In science

Re: [time-nuts] UTC and leap seconds

I was wondering, why we assume that Earth's rotation is slowing down, instead that clocks are speeding up? Antonio I8IOV Hi Antonio, Good question. If all you had is one clock; then it is the time. If you have two clocks you can see them drift apart (if you can't, then you either aren't lo

Re: [time-nuts] UTC and leap seconds

Beside the general theoretical considerations as of what answer is more acceptable (sincerely I agree so far) and what method could be used to solve the matter, can anybody out there point me please to any article on actual measurements of the variation rate of the earth's rotational speed, no

Re: [time-nuts] UTC and leap seconds

I think the answer is in your previous post, that is the year is more stable than the day as compared to the same clock. And this measurement very likely has been actually made. Antonio I8IOV Right. Defining a second as 1 / 86400 of the length of a mean solar day is also problematic because

Re: [time-nuts] Advantages & Disadvantages of the TPLL Method

Here are a couple of really good articles that describe many methods of phase/frequency measurement, including TPLL. You'll see some nice "advantage/disadvantage" lists in several of these documents, which is why I'm posting the links. Warren & Bruce, please look at the first five documents at le

Re: [time-nuts] NPR Story I heard this morning

> Yes, A story about time and frequency standards. They actually used > numbers like 10E16 in the story. Apparently at that level your clock can > measure a change in elevation of a few centimeters because of the > relativistic effects of the reduced gravity field in just a few cm. Hi Chris, T

Re: [time-nuts] NPR Story I heard this morning

> I have a question about that. If I understand correctly, recent IAU > resolutions have decoupled the definition of the SI second from the > terrestrial geoid, which is too fuzzy to be used for a definition. Instead > the geoid potential is held fixed by (or defined by) a constant. Potential >

Re: [time-nuts] NPR Story I heard this morning

David, Let's talk. It is not impossible that I could drive my clocks to the East Coast for a Mt. Washington experiment. /tvb - Original Message - From: "David McGaw" To: "Discussion of precise time and frequency measurement" Sent: Monday, November 03, 2014 1:07 PM Subject: Re: [time-

Re: [time-nuts] NPR Story I heard this morning

> I don't see anything in the BIPM definition of the second regarding sea level. Hi Mike, The usual wording for the definition of the SI second also includes the word "unperturbed". That little word covers a host of physics and engineering effects and can keep graduate students busy for years.

Re: [time-nuts] NPR Story I heard this morning

ocks, but also precise time measurement, and about disciplining. Whether UTC at a national lab or a GPSDO at home, there is clock, measurement, and gradual adjustment. /tvb - Original Message - From: ken hartman To: Tom Van Baak ; Discussion of precise time and frequency measurement

Re: [time-nuts] Varian R-20 Rubidium Frequency Standard

Hi Adrian, I have a Varian R20 here, along with its op/svc manual. Contact me off-list. /tvb - Original Message - From: "Adrian" To: "Discussion of precise time and frequency measurement" Sent: Tuesday, November 04, 2014 7:34 AM Subject: [time-nuts] Varian R-20 Rubidium Frequency Stan

Re: [time-nuts] KS-24361 GPSDO question

> Last comment > Seems a shame there is not a repository we could add all this good > information to. > I believe its going to get lost with this method. Hi Paul, The time-nuts list is sort of a repository. Or at least that's what it was intended to be. The list works best when the number of pos

Re: [time-nuts] Practical considerations making a lab standard with an LTE lite

The short-term performance is 10x worse if you don't shield the TCXO from air, even if the ambient air is "still". I suggested Said sell the product with some sort of engineered shield in place. Instead each of us will solve the problem in our own way; which is ok for a dev kit. For plots and p

Re: [time-nuts] Homebrew frequency counter, need help

A copy of the plots is at: http://leapsecond.com/tmp/lllaaa-1.gif http://leapsecond.com/tmp/lllaaa-2.gif Your project sounds wonderful. The TDC-GP22 has been mentioned only a few times over the years and I keep waiting for someone to post actual results from this chip, or bett

Re: [time-nuts] How can one measure ADEV of a good oscillator?

> I think I have a flaw in my understanding of this. > > How can something like an SR620 measure the ADEV of an oscillator, if the > oscillator is of a similar or better than the reference fed into the SR620? The key is to realize that all measurements are actually just comparisons: the instrum

Re: [time-nuts] HP 5061Cs reference question

Paul, There are 7 peaks total, about 40 kHz apart (on my 5061A). If you're talking about just the central peak, there are two smaller peaks on either side, about 1 kHz apart. The exact value depends on internal magnetic field, which is specific to each beam tube design. For some measurements o

Re: [time-nuts] HP 5061Cs reference question

z output". /tvb ----- Original Message - From: "Tom Van Baak" To: "Discussion of precise time and frequency measurement" Sent: Saturday, December 06, 2014 9:04 AM Subject: Re: [time-nuts] HP 5061Cs reference question Paul, There are 7 peaks total, about 40 kHz apart (o

Re: [time-nuts] Homebrew frequency counter, need help

quot;, 14, t); ref_curr = refcnt - t3; sig_curr = sigcnt; t = CalcFreq(ref_curr - ref_start, sig_curr - sig_start); // without linear regression printf(" Interpolated=%.*f", 12, t); msecond = 0;

Re: [time-nuts] Homebrew frequency counter, need help

Li, > Since I really want to reduce the noise, what is the best test set you > suggest? ... > How to analyze the ADEV plot to get information about noise? Note these two statements are at odds. On the one hand we all want to reduce noise. But ADEV is all about measuring noise, not making it go

Re: [time-nuts] gravity, space and time

> If I understood it well, we should occasionally encounter gravitational > waves going through, well, the whole galaxy. As time and space are > intertwined, those ripples may be measured somehow I guess. > Isn't this that "we as time nuts community" can help the scientific > world with? E.g. creat

Re: [time-nuts] Linear voltage regulator hints...

> ** I'm assuming that the GPS does not use the OCXO output for its > own timing. That is such a good idea, I can't understand why more > designers don't do it. It adds to the cost. If the end-user only needs XO or TCXO quality timing, there's no incentive to increase the size and cost and po

Re: [time-nuts] Linear voltage regulator hints...

>>Note that most high-end GNSS timing receivers go one better and >>simply have an external input for the clock. That way you feed your >>own lab clock into the receiver. If you have Rb/Cs/maser you would >>use that as the reference. It's what the national timing labs do, >>along with dual-freq

Re: [time-nuts] Ventilation of HP 58503A GPS time & frequency reference receiver

If any of you want me to post more photos let me know. I have several of every kind of HP/Agilent GPSDO product. And they are all genuine because I bought them a decade before the China/eBay/GPSDO business. Right, I probably should have included some of HP's GPSDO products in the "hpclocks" pho

Re: [time-nuts] Ventilation of HP 58503A GPS time & frequency reference receiver

this thread. Thanks, /tvb - Original Message - From: Dr. David Kirkby (Kirkby Microwave Ltd) To: Discussion of precise time and frequency measurement ; Tom Van Baak Sent: Sunday, December 14, 2014 10:38 PM Subject: Re: [time-nuts] Ventilation of HP 58503A GPS time & frequency

Re: [time-nuts] Choke Rings and Points North

> With all the discussion about surveys & position accuracy, I have a question > about my choke ring antenna. There is an arrow marked "N" on the underside > of the rings. How accurately does the alignment need to be to "N"orth? > True north or magnetic north (my thinking says True North)? >

Re: [time-nuts] Choke Rings and Points North

> Clever idea, but.. > > Most rotary joints have more phase and amplitude variability than the > antenna. > > So you're stuck with rotating back and forth with a cable that's flexing > and now you get to measure the phase variability of the coax. I was thinking of some sort of non-contact RF b

[time-nuts] Time Nuts Overload

Hi everyone, The past couple of weeks or month it seems we've had a lot more traffic than usual. This is a reminder that there are 1300 of us and we look forward to rich content on this list. Postings that have little technical content, or are based on guessing, or are just one-liners, or ar

Re: [time-nuts] Time Nuts Overload, part 2

inable. Members tune out. Members leave. Something had to change. So one of the goals is getting back to just 10 or 20 interesting and informative time nuts postings per day; on a wider variety of topics; by a wider variety of members, old and new. Thanks, /tvb - Original Message -----

Re: [time-nuts] HP 53131A - reset security code

Ulli, You're right. The actual procedure is not described in the manual(s): Operating Guide http://cp.literature.agilent.com/litweb/pdf/53131-90055.pdf Programming Guide http://cp.literature.agilent.com/litweb/pdf/53131-90044.pdf Assembly-Level Service Guide http://cp.literature.agilent.com/li

[time-nuts] June 30 2015 leap second

Just announced: there will be a positive leap second at the end of June 30 2015 UTC (that's Wednesday July 1st for most of the world). As usual we time nuts will have a leap second party -- where we capture and share the magic hh:59:60 display on as many different clocks and instruments as poss

Re: [time-nuts] June 30 2015 leap second

leap second consideration. Most likely not. > And that means its only accurate for the present and pas time. Right ? > For my clock I already implement the function for the leap second and I > am able to add/remove number of seconds from the time I receiving from > GPS or any other so

Re: [time-nuts] June 30 2015 leap second

> The difference between GPS time and UTC (due to leap seconds) is > broadcast in the GPS navigation message[1] so all but the most poorly > designed GPS modules should take care of it and output the correct UTC time. Henry, This is not quite true. First, page 18 of subframe 4 is only broadcast e

Re: [time-nuts] June 30 2015 leap second

> I couldn't help noticing that Debian just issued an update > to tzone, so that means Linux systems now know about the > leap second. > > -Chuck Harris Hi Chuck, "Linux systems now know about the leap second" -- this is a very dangerous assumption. And one reason why leap seconds have gotten

Re: [time-nuts] Mechanical 1PPS Oscillator Disciplining

Andy, Yes, Neal Stephenson's Mother Earth Mother Board article is a classic that every time nut should read at some point. The "one page" version is at http://archive.wired.com/wired/archive/4.12/ffglass_pr.html Prior to quartz, pendulum clocks and tuning fork oscillators were the standard. Ev

Re: [time-nuts] Mechanical 1PPS Oscillator Disciplining

Alex, Now it's time to share some of my favorite vintage time & frequency links. Some very nice vintage low frequency quartz crystals (20 kHz down to 5 kHz): http://www.cdvandt.org/luminous_quartz.htm Lothar Rohde's revolutionary "portable" quartz-clock type: CFQ http://www.cdvandt.org/CFQ.pdf h

Re: [time-nuts] June 30 2015 leap second

>> I haven't looked at the raw data, but using the windows apps: >> a Trimble Resolution SMT is showing the leap pending a Motorola UT+ is not. >> lady heather is not > > Interesting. I don't see any leap-pending from a Z3801A. (or a KS-24361) Hi Hal, It's not that simple. There are many dif

Re: [time-nuts] June 30 2015 leap second

> Keep in mind that this system drives you to having pretty bad time for the > better part of a whole day, on purpose... I realize that when the Hi Didier, The google article never claims the smear spans an entire day. I think you may be confusing references to the leap smear with a DIY digital

Re: [time-nuts] Sources for Mission Time Clock

Martin, 1) Check out www.masterclock.com - they regularly exhibit at PTTI with a wide variety of metrology-grade clock displays. The prices were reasonable, although you could make one yourself for half the price if you spend a couple of weeks of your own time. 2) Scroll through http://www.go

Re: [time-nuts] Arduino GPIB

> Yes, you can get an Arduino R3 on eBay for <$4 with shipping... > > The GPIB connector will cost you more! > > Didier KO4BB A sandwich of two PCB is about the same thickness as the center plug of a GPIB male connector. So layout 2x12 pads to match the pins and you have a one-piece Arduino an

Re: [time-nuts] FOSDEM 2015 has a time-track

Hi Attila, I was told some of the time slots of https://fosdem.org/2015/schedule/track/time/ might be tentative but we'll all get together after the last talk, whenever it is. So far everyone I've heard from has the evening open. Time nuts -- if you're within a couple hundred km of Brussels it

Re: [time-nuts] L1 and L2 frequencies

> I have some questions on GPS and GNSS. Note GNSS is the generic word for any satellite based navigation system. GPS is one of GNSS so you don't actually need to say GPS *and* GNSS. > Do all the civilian GPS receivers only operate on the L1 frequency? No. All the cheap ones do, though. > Are

Re: [time-nuts] New algorithm, better ADEV

Hi Li Ang, You're making good progress. Thanks for the update and the photos. I am impressed with both the project and the way you are documenting and sharing the progress on the qsl.net web site. The new algorithm is good. Yes, the whole idea of a timestamping counter is that you start it onc

Re: [time-nuts] Sources for Mission Time Clock

> I know precisely what you are saying and I get the feel. Nixie clocks seem > so much cooler than seven-segment LED clocks. (And vacuum fluorescent just > seems cheesy. Go figure.) So early '60s is retro but late '60s is not. From > my view 50 years down the road that seems just ... humorous. Bri

Re: [time-nuts] GPS 1PPS ultimate accuracy

Hi Andrea, Making measurements of quartz oscillator aging is much easier than you think and requires minimal equipment. In particular all you need is a GPS 1PPS and a simple counter. No need to worry about sawtooth. Any $20 GPS/1PPS receiver will work. Consider this rough example of measuring

Re: [time-nuts] L1 and L2 frequencies

> If we had dual or tripple frequency receivers below 500 USD things would > start to be interesting. If high-volume kits would be just twice as > expensive, it would be possible to consider for more luxury models. Hi Magnus, I am currently (but slowly) evaluating about a dozen near identical,

Re: [time-nuts] New algorithm, better ADEV

>I'm doing a longtime test with this counter. The DUT and Reference > are from the same X72 Rb oscillator.The X72 is powered by a R&S linear > supply, the counter is powered by laptop USB port. I started the test > 1 hour after the Rb is locked. >I have uploaded the test data about 2 days t

[time-nuts] Time Nuts Overload, 30 day status

Hello fellow time nuts, As many of you know, there was a slow meltdown of the time-nuts mailing list late last year. We put a stop to it mid-December (see [1] and [2]). The goal was to get the list back to 10 to 20 high-quality postings per day. The list was sort of turning into a social networ

Re: [time-nuts] Oscilloquartz 2200 Clock / B-5400 Oscillator

Hi Adrian, I have a working Oscilloquartz B-5400. A copy of the data sheet is at: http://leapsecond.com/museum/osa5400/1982-OSA-B-5400-ds.pdf but I do not have a manual for it. Did you happen to take some photos when you did the repair? I'd like to see the inside, but since mine is working I

Re: [time-nuts] Can one update firmware of Stanford Research Systems SR620 time interval counter?

I heard back from SRS and 1.48 is the current f/w rev level for the SR 620. List -- we're still tracking down the root cause of the strange response Dave is seeing from his *IDN? command. There was some questionable usage of ibwrt() and ibrd() and atof() in his test program as well as possible E

Re: [time-nuts] Ublox 6T receiver, noisy PPS.

Dan, I echo what Azelio is saying. During the time when you are "evaluating" a GPS receiver it is important to collect as much data as possible, just in case you need to go back and correlate unusual events. I tend to turn on all possible binary messages and collect tens or hundreds of MB. You

[time-nuts] GPS leap second pending (HP/SmartClock)

And not to be left out of the pre-leap second party, those of you with HP/Symmetricom SmartClock's can also have fun. That would include the 58503-series T&F standards as well as most of the Z38-series. Send these commands ASAP and (surprise) see what you get: *cls :ptim:leap:acc? :

[time-nuts] GPS leap second pending (TBolt/Heather)

I was just sent a nice TBolt / Heather.exe screenshot from alert time-nuts reader Steven Reyer showing "LEAP PENDING!". The good news is that, yes, there will be another leap second (in June). The bad news is that, no, there is not a leap second at the end of this month (January) nor at the end

Re: [time-nuts] 2015 Leap Second

tware that used to work just fine. /tvb - Original Message ----- From: Charles Zabilski To: Tom Van Baak Sent: Saturday, January 24, 2015 9:47 AM Subject: 2015 Leap Second Tom: Unfortunately I no longer receiver emails from time nuts due to my @yahoo.com email address. In re

Re: [time-nuts] 2015 Leap Second

More info from Charles (stuck in time-nuts @yahoo @aol prison): /tvb - Original Message - From: Charles Zabilski To: Tom Van Baak Sent: Saturday, January 24, 2015 1:52 PM Subject: Re: 2015 Leap Second Tom: Thanks for the update. I got around that problem in later

Re: [time-nuts] GPS leap second pending (Fury/Z38XX)

Well, Said can tell us for sure (since he owns the firmware in the Fury) but you could call this is correct, because: 1) a leap second is not pending this month 2) the current leap second count is still 16 3) the next leap second happen between 2015-06-30 and 2015-07-01 4) the current month ends

Re: [time-nuts] GPS leap second pending (Fury/Z38XX)

Hi Hans, Actually, it is quite common to name the leap second by the July / January date instead of the June / December date. As you read papers on the web, use automated leap second services, or interact with instruments be prepared for both styles. As an example, note that the most official

Re: [time-nuts] Help me make some sense of adev measurements of SR620'sown clock

> http://www.kirkbymicrowave.co.uk/time-stuff/ref-out-to-A-3.6m-cable-to-B-rev4.zip > > The format should be pretty self-explanatory. Note the counter sample Well done, nicely self-documenting. > I then used Tom's "adev1" > > http://www.leapsecond.com/tools/adev1.htm > http://www.leapsecond.com

Re: [time-nuts] LTE Lite time error

Hi Paul, Odd, my LTE-Lite appears spot on. Let's take this off-list and see what's going on. If anyone else has been logging SkyTraq NMEA or binary from the LTE-Lite let us know. Thanks, /tvb $SkyTraq,Venus8 $Kernel,v2.0.2,1C92,1426,6005,I,16.367667MHz $ver,010827,rev,130221 - O

Re: [time-nuts] LTE Lite time error

> I have verified the Skytraq claim on my stand alone NS-T. > Tue Jan 27 06:52:06 UTC 2015 $GPGGA,065206.000,4847.3506 Hi Mike, Please use more precise timestamps so your results can be believed. In general it's not adequate to use one second unix time stamps to identify a possible one second N

Re: [time-nuts] Motorola Oncore M12+T Sawtooth

google for: m12 gps sawtooth The +/- 127 comes from the range of 8 bits. /tvb (i5s) > On Jan 29, 2015, at 12:44 PM, Tom Wimmenhove wrote: > > I've built a bunch of carrier board for the M12+T timing receiver. One > thing I could not find much information about is the maximum sawtooth > (which,

Re: [time-nuts] Newbie question

Hi Stuart, Also contact Joe Geller, who was active on time-nuts some years ago, and who wrote the ultimate 53310a reference page: http://www.gellerlabs.com/hp53310a.htm /tvb - Original Message - From: "Stuart Rumley" To: Sent: Thursday, February 05, 2015 9:21 PM Subject: [time-nuts]

[time-nuts] Navy Frequency & Time Standard Equipment

I found a site with wonderful photos and documents related to old time & frequency gear. http://www.navy-radio.com/freq-equip.htm Note also this detailed history of NRL: http://www.navy-radio.com/manuals/nrl-history.pdf /tvb ___ time-nuts mailing list

Re: [time-nuts] Measuring frequency rather than tuning crystal

Paul, Right, there's no need to physically calibrate the LO when you can simply adjust all measurements in software, either inside the instrument or on the PC that's logging the measurements from the instrument. This technique is used for many high-end measurements and also extends to GPS post

Re: [time-nuts] No GPS satellites

Mike, That's the same card I used for the 40-day run: http://leapsecond.com/pages/mains/ It's robust and professional (used in the electric grid industry) and nice if you already have a working XL-DC but most of us now use a $1 microcontroller or DCD pin and NTP to track mains phase & frequenc

Re: [time-nuts] patek phillipe digital clock, sold as curio/antique

> In yesterday's Wall Street Journal (or maybe USA Today, I can't remember..) > > Nice Nixie displays... > I wonder if it normally displays the same time on all, or if it is a > multi-time zone/elapsed time kind of thing. It looks a lot like clock > display stacks used for displaying Mission El

Re: [time-nuts] homebrew counter new board test result

> 2) Does any one have the test data of 12 digit/s counter when DUT=REF? > I want to know the gap between mine and a commercial counter. > > > Thanks > > Li Ang I did a lot of testing of 53132A counters a while back to research how well the interpolators worked and to measure the interference

Re: [time-nuts] Recording mains frequency/phase [WAS: No GPSsatellites]

> If we all did this, then I realize that we could identify the different > power grids. However, I wonder if there is any interesting variation > *within* a grid. As the electricity flows vary throughout the day, it > seems possible that the phase difference between two people on the same > gr

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