Re: [time-nuts] Lady Heather's Tbolt oscillator auto-tune function

> > Bob, that is an excellent proof by contradiction. The reason I asked is on > the plot Mark shared that first rising edge is pretty sharp for a system > with a 500 s time constant. > > On Tuesday, 13 September 2016, Bob Camp <kb...@n1k.org> wrote: > >> Hi >>

Re: [time-nuts] Faulty Tbolt?

Hi There is a temperature monitor IC on the TBolt PCB. It is an older Dallas Semiconductor part. You can dig into the archives for all the details on which version gives you the best results. The simple answer is that it’s not hurting anything and there is no real reason to fix it, unless you

Re: [time-nuts] HP-105B Battery Replacement?

Hi A bigger question becomes: Do batteries inside equipment make much sense anymore? These days, a UPS is often a standard part of a rack in an outage prone area. Powering the “whatever” instrument off of the same UPS as the rest of the stuff is one obvious answer. The other answer is an

Re: [time-nuts] Vintage Quartz Crystal Manufacturing

Hi It’s interesting how much controversy that film stirred up. Literally 30 years after it was made, you could get a fairly excited conversation going about it at the FCS. On one side were the people who felt it was a sweetheart deal to Reves at a point that other companies were being

Re: [time-nuts] Lucent RFTFm-II-XO- Lady Heather question-having issues

Hi In Windows, the icon on the desktop has a set of properties. One of those is the command that clicking the icon executes. Adding the appropriate com info there will get it headed to the correct port. Bob > On Sep 24, 2016, at 1:30 PM, Chris Waldrup wrote: > > Hi, > >

Re: [time-nuts] COTS cesium standard physics package life

Hi Are you interested in improving the likelihood of the unit working 30 years out or of it working 15 years out? The “operating” case will ultimately kill various parts in the standard that would not die sitting on the shelf. The pumping process *may* extend the life of the tube….. What the

Re: [time-nuts] COTS cesium standard physics package life

Hi The real questions are: 1) Over what period of time can you get a replacement under warranty. 2) How long on average is the tube likely to be useful. There are numbers for each. It just depends on which one you are after. Bob > On Sep 29, 2016, at 8:07 AM, Ruslan Nabioullin

Re: [time-nuts] COTS cesium standard physics package life

Hi If you operate the device continuously for 30 years, you *will* have other parts in it fail. The MTBF of the system (without the tube) is *not* infinite. Bob > On Sep 29, 2016, at 2:08 PM, Ruslan Nabioullin <rnabioul...@gmail.com> wrote: > > On 09/29/2016 02:02 PM,

Re: [time-nuts] COTS cesium standard physics package life

Hi > On Sep 29, 2016, at 1:16 PM, Ruslan Nabioullin <rnabioul...@gmail.com> wrote: > > On 09/29/2016 01:03 PM, Bob Camp wrote: >> 2) How long on average is the tube likely to be useful. > > So you are implying that the package life is depleted at a roughly equal ra

Re: [time-nuts] Need Time Help

deal. If it *is* a big deal, run a GPSDO and then it’s no longer a problem. The KS boxes still seem to be out there for < $100 …. Bob > On Oct 5, 2016, at 2:32 PM, Gary E. Miller <g...@rellim.com> wrote: > > Yo Bob! > > On Wed, 5 Oct 2016 07:14:30 -0400 > Bob

Re: [time-nuts] ADC sample voting algorithm?

Hi What does the signal you are sampling look like? Does it (maybe) have a bit of noise on it? If it is the output of a “normal” TDC, then the answer is to sample once. Bob > On Oct 5, 2016, at 7:45 PM, Nick Sayer via time-nuts > wrote: > > This is tangentially on

Re: [time-nuts] ADC sample voting algorithm?

noise is not an issue. Bob > On Oct 5, 2016, at 8:22 PM, Nick Sayer via time-nuts <time-nuts@febo.com> > wrote: > > >> On Oct 5, 2016, at 5:00 PM, Bob Camp <kb...@n1k.org> wrote: >> >> Hi >> >> What does the signal you are sam

Re: [time-nuts] Need Time Help

Hi If you buy a GPS receiver and get it set up for timing …. just use it. Then there is no need for NTP at all…. Bob > On Oct 5, 2016, at 12:33 AM, Chris Albertson <albertson.ch...@gmail.com> > wrote: > > On Tue, Oct 4, 2016 at 6:52 PM, Bob Camp <kb...@n1k

Re: [time-nuts] Need Time Help

gt; wrote: > > Given the number of replies to the OP, most pointed but others drifting OT, > it is remarkable that there has been no comment or feedback from Larry. He > has slung his bottle and gone away it seems. > > >> Le 5 oct. 2016 à 23:58, Bob Camp <kb...@n1k.o

Re: [time-nuts] Need Time Help

Hi As others have mentioned, you have two strikes against you: 1) Modern laptops *love* power saving. That makes them poor time keepers at the millisecond level. It takes some well thought out software in the OS to keep track of all the strange things they do. 2) Windows XP is getting a bit

Re: [time-nuts] AC line distortion [Was: HP 105B Battery, the saga continues]

Hi A lot of the distortion on the AC line is locally produced. Consider a very normal bridge rectifier running into a capacitor. It draws “all” the current in narrow spikes near the peaks of the sine wave. A half wave rectifier would be even worse (only one spike per cycle). That highly

Re: [time-nuts] Prologix USB-GPIB Controller

Hi That’s been my experience as well over the last few decades, based on using a variety of adapters. Bob > On Oct 7, 2016, at 5:36 PM, John Miles wrote: > >> thanks for the offer, Geo >> We've already found a new Prologix unit at much less than retail. I'm not >> familiar

Re: [time-nuts] Inexpensive Alternative to a 5120A

Hi Last time I saw a price on a 5120A, it was in the > $30K range. That was a while ago so things may have changed for better or for worse. A TimePod is roughly 1/3 of that. Either way, pretty expensive for a basement lab. Bob > On Oct 7, 2016, at 12:52 PM, Cube Central

Re: [time-nuts] Prologix USB-GPIB Controller

Hi One thing to be *very* careful of on all of these adapters: They get counterfeited a *lot*. All bets are off when you get one that is not the “real deal”. Far better to source it from a trussed source for a bit more money than to take a risk on a dubious clone. Bob > On Oct 7, 2016, at

Re: [time-nuts] Need Time Help

ast partly because asking a relatively simple > question here routinely turns into a dissertation defense. > >> On Oct 6, 2016, at 3:45 AM, Bob Camp <kb...@n1k.org> wrote: >> >> Hi >> >> That’s very typical in a lot of forums. The OP tosses up a qu

Re: [time-nuts] ntp and asymmetric delays

Hi NTP can *not* detect “common mode” asymmetric delay. Having a local GPS does not count in this respect. What does count is an NTP client / server sitting in your home trying to figure out what time it is only by hooking to the internet. To do this it must do a few things: 1) Get a signal

Re: [time-nuts] Measure GPSDO stability with minimum resources?

has been my biggest foe in this project. > > Bob > - > AE6RV.com > > GFS GPSDO list: > groups.yahoo.com/neo/groups/GFS-GPSDOs/info > > From: Bob Camp <kb...@n1k.org> > To: Discussion of precise time

Re: [time-nuts] Measure GPSDO stability with minimum resources?

Hi As normally used, the term “aging” means the long term drift in the frequency of an OCXO. It is independent of the temperature effects and things like retrace, warmup, and voltage stability. It is rare that there is any impact on the aging of a properly designed OCXO from drift of the

Re: [time-nuts] Need Time Help

Hi If: 1) You are a typical Ham in a home environment 2) All the servers are “out there” on the internet 3) You have any of the normal modems feeding your home You have a very basic issue in terms of path delay. All the servers you can access have the *same* asymmetric delay. In that case, no

Re: [time-nuts] Prologix USB-GPIB Controller

Hi Yes indeed it is true of pretty much ever single GPIB adapter out there. The issue is that the innards are not terribly complex and the sell price on eBay is fairly high compared to the material content. Bob > On Oct 7, 2016, at 9:13 PM, Hal Murray wrote: > >>

Re: [time-nuts] Inexpensive Alternative to a 5120A

uild a DMTD with a stable / low noise reference rather than the poor stability reference in a SDR dongle. Again, no free lunch :) Bob > > > On Sun, Oct 9, 2016 at 4:16 PM, Bob Camp <kb...@n1k.org> wrote: >> Hi >> >> >>> On Oct 9, 2016, at 6:18 P

Re: [time-nuts] TimeLab

er GPIB adapter this Christmas. >> >> Bob >> ----- >> AE6RV.com >> >> GFS GPSDO list: >> groups.yahoo.com/neo/groups/GFS-GPSDOs/info >> >> From: Bob Camp <kb...@n1k.org>

Re: [time-nuts] TimeLab

address multiple devices. Bob > > Bob > - > AE6RV.com > > GFS GPSDO list: > groups.yahoo.com/neo/groups/GFS-GPSDOs/info > > From: Bob Camp <kb...@n1k.org> > To: Discussion of precise time and fre

Re: [time-nuts] TimeLab

s easier to analyze is the > improved support for zooming. > > Oh, I do care about phase variations and absolute phase measures. I do such > measures a lot. ADEV and TDEV is not all the things I measure, especially > when considering systematic effects. > > Cheers, > M

Re: [time-nuts] TimeLab

Hi Given that *some* of us have more than errr … one counter :) There are several setups that involve two or three counters to resolve some of these issues. Having multiple serial ports or multiple devices on a GPIB isn’t that big a problem. Addressing multiple devices (setting up the

Re: [time-nuts] Thunderbolt spurs on 10MHz output at 100Hz and 200Hz from signal.

Hi If you are measuring the OCXO, you should be getting around -155 to -160 dbc / Hz at 100 Hz offset. Depending on the particular board you have, and how it is powered, the numbers out of the TBolt can be quite a bit worse than this. With a good supply, you should get within 5 db. There are

Re: [time-nuts] HP-105B Battery Replacement?

gt; another good alternative. Harder to move around but I don't (yet) have such a > need, only that the 105B stay "on" regardless of power failures. > > Jeremy > > > On 9/15/2016 10:15 AM, Bob Camp wrote: >> Hi >> >> A bigger question becomes: >

Re: [time-nuts] Adjusting nominal frequency of FTS 1200-100 OCXO?

Hi Best guess: It’s inside the styrofoam block. It’s inside a sealed can in the block It’s (maybe) inside a can inside that one. It’s a SMT part on a board in that can. You set the frequency by pulling what they have there, measuring it and putting in another cap. If they used a series like

Re: [time-nuts] Lucent RFTFm-II-XO

bad. > > 15625 from 3586 goes in one channel and pps goes into the other channel of > the sound card and SL does its magic. > > 73, > > Bill, WA2DVU > Cape May > > -Original Message- > From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob Camp

Re: [time-nuts] Normal operating specs of a Morion MV89?

Hi There is an output coupling cap that is close to the output pin. It is not clear if it is failing or simply damaged by the salvage process. Best guess is that some fail, but far more are damaged parts. Bob > On Sep 20, 2016, at 6:09 PM, Alex Pummer wrote: > > Hi

Re: [time-nuts] Normal operating specs of a Morion MV89?

Hi At least the MV89’s that I have bought have been mostly defective. The issues in them are many and some of them are only apparent with fairly exotic testing There are a lot with defective output capacitors, but many of those also have other issues as well. Unless you have a lot of time,

Re: [time-nuts] 53132A triggering

Hi Set it up on your 53132 and see what happens … Bob > On Sep 16, 2016, at 8:35 PM, Scott Stobbe wrote: > > For a low duty cycle pulse, the ac coupled signal will be approximately the > same as if it were dc coupled. Not sure I follow what you mean. There will > be

Re: [time-nuts] HP-105B Battery Replacement?

Hi Any time you get into UPS designs, they are all over the map … > On Sep 16, 2016, at 1:01 PM, Gary E. Miller wrote: > > Yo Hal! > > On Fri, 16 Sep 2016 00:50:56 -0700 > Hal Murray wrote: > >> g...@rellim.com said: >>> APC UPS can't handle the

Re: [time-nuts] 53132A triggering

Hi Set it to: 1) DC coupled (AC does not go low enough) 2) 50 ohms if your driving source will tolerate it, otherwise 1 meg ohm. 3) Manual trigger mode (Auto is to fast and it forgets where the trigger should be) 4) Trigger level around 1/2 the PPS P-P voltage Once set up that way, the

Re: [time-nuts] Adjusting nominal frequency of FTS 1200-100 OCXO?

Hi As long as we are cataloging all this stuff: The run of the mill OCXO has a hermetic case on it. You get in and out of the case via pins with glass to metal seals. One of the common things to make the pins out of is Kovar. It’s great stuff, matches the TC of glass fine, easy to work with.

Re: [time-nuts] Normal operating specs of a Morion MV89?

Hi Compared to some MV89’s that’s a bit cold….It certainly is not alarmingly hot for an OCXO case. Bob > On Sep 19, 2016, at 5:31 PM, Tim Lister wrote: > > I recently ordered and received what claims to be a 2007 vintage > Morion MV89 from ebay (I say claimed as that

Re: [time-nuts] Lucent RFTFm-II-XO

Hi I have had no problem using the PPS out of any of the Lucent boxes. They trigger counters fine and a one shot stretches them to any length you might need. Bob > On Sep 22, 2016, at 8:31 AM, Bill Riches wrote: > > Be careful of the pps output from the dual lucent

Re: [time-nuts] GPSDO - probably a stupid question.

Hi A mixer style phase detector running a GHz range oscillator is one example of a system that technically updated the EFC several billion times a second. There does not have to be a DAC involved. The point is still looking at the noise characteristics of the oscillator and the reference.

Re: [time-nuts] Normal operating specs of a Morion MV89?

Hi You have one of the many MV89A’s with an output problem. To be absolutely sure of the output, you need to have the scope set to 50 ohm input. If it was set to Hi-Z, the output is likely even lower….. Bob > On Sep 28, 2016, at 1:38 AM, Tim Lister wrote: > > On Tue,

Re: [time-nuts] Rare HP clock

Hi Rare is indeed a relative term. I would certainly call it rare, but others might not. You likely would be the only person on your block who has one :) In the picture of the innards you can see a number of fine old wet slug tantalum capacitors. One even appears to have goo leaking out of

Re: [time-nuts] crystal notch filter // numbers

hese findings. > Best regards, > Adrian > > > > From: time-nuts [time-nuts-boun...@febo.com] on behalf of Bob Camp > [kb...@n1k.org] > Sent: Monday, October 03, 2016 12:17 AM > To: Discussion of precise time and frequency measurement

Re: [time-nuts] notch filter for close in phase noise measurement

ethode, remain. > Sooner (or later) I shall share with you (after the real life validation) an > (again, very simple) interderometric methode. > Adrian > > Sent from my BlackBerry 10 smartphone on the Orange network. > Original Message > From: Bob Camp > Sent: Sunday, Octobe

Re: [time-nuts] notch filter for close in phase noise measurement

e it was funy > to _discover_ that simple topology doing a notch. > ‎Best, > Adrian > > Sent from my BlackBerry 10 smartphone on the Orange network. > Original Message > From: Bob Camp > Sent: Sunday, October 2, 2016 18:35 > To: Discussion of precise time and frequency measure

Re: [time-nuts] notch filter for close in phase noise measurement

ttings. The bandwidth is > much, much lower than 30Hz. From memory, the -58dB notch is valid for 0.1Hz > freq shift only. > Adrian > > Sent from my BlackBerry 10 smartphone on the Orange network. > Original Message > From: Bob Camp > Sent: Sunday, October 2, 2016 22:09 &

Re: [time-nuts] notch filter for close in phase noise measurement

;cfhar...@erols.com> wrote: > > That is a most interesting suggestion. > > Suppose the filter crystal was pulled to the DUT frequency, and due > to the inertia of its very high Q, was able to show you the phase noise > variations of the DUT better than one might expect? >

Re: [time-nuts] notch filter for close in phase noise measurement

> > On Sunday, 2 October 2016, Bob Camp <kb...@n1k.org> wrote: > >> Hi >> >> The issue is *not* about notch filters and if they are useful. The gotcha >> is >> that they are mainly useful far removed from carrier rather than close in. >> The &

Re: [time-nuts] Vintage Quartz Crystal Manufacturing

> (at CubeCentral) > > > -Original Message- > From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob Camp > Sent: Saturday, 24 September, 2016 09:53 > To: Discussion of precise time and frequency measurement <time-nuts@febo.com> >

Re: [time-nuts] Vintage Quartz Crystal Manufacturing

tive at RCA oversaw the making of > several of these films. I do not believe that the companies profited > greatly from their production. As to advertising, would watching that film > make you run out and buy a box of crystals? > > On Sun, Sep 25, 2016 at 9:53 AM, Bob Camp &l

Re: [time-nuts] Measuring phase with an HP 3456A?

is. When someone talks about quadrature, > it looks to me as though they are waving hands in the air, saying some > incantations, and then come up with miracles. I know it works but I surely > would love to understand it. > Bob > > >On Saturday, October 1, 2016 4:24 P

Re: [time-nuts] Measuring phase with an HP 3456A?

t; Ever since data streams seem to take less bandwidth than that of the signals > whose information they contain, I have been thoroughly confused. My classic > textbooks don't have stuff like this. When someone talks about quadrature, > it looks to me as though they are waving hands

Re: [time-nuts] Schematic needed

Hi Be *very* careful hooking up to a 5680. There are an unfortunately large number of pinouts and power options. As far as anybody knows, there is no easy way to figure out what you have from the outside of the unit. Since the connections are incompatible with each other, the “try it and see”

Re: [time-nuts] notch filter for close in phase noise measurement

Hi Getting close to carrier with a notch filter involves a bit of calibration of the notch. It’s not imposible to do, but it is a needed step. The generator you use to do the measurement has to be pretty clean to get adequate data at low offsets. Bob > On Oct 2, 2016, at 3:56 AM, Adrian Rus

Re: [time-nuts] notch filter for close in phase noise measurement

simplicity (as compared to other notch > approaches). > Best regards, > Adrian > > Sent from my BlackBerry 10 smartphone on the Orange network. > Original Message > From: Bob Camp > Sent: Sunday, October 2, 2016 17:06 > To: Discussion of precise time and frequency

Re: [time-nuts] Measuring phase with an HP 3456A?

Hi What is the beat note coming out of the DMTD? Put another way: DMTD involves three oscillators. Two are on roughly the same frequency and the third is offset from the other two. The difference frequency is typically something like 10 Hz. It does not *have* to be 10 Hz, but that is one

Re: [time-nuts] Normal operating specs of a Morion MV89?

HI > On Oct 1, 2016, at 4:08 PM, Scott Stobbe wrote: > > If you used a 6db pad in conjunction with a 50 ohm termination you are spot > on. If you used a 6dB pad as a 50 ohm load, the effective load will be a > bit higher than 50 and the attenuation less than 6 dB.

Re: [time-nuts] Measuring phase with an HP 3456A?

I would see on the 3456A?" sort of thing. I'm running a > holdover/recovery test on the code and hardware changes to get a reliable > 1PPS from my GPSDO, so there is some very slow movement over the range of 0 > to 100ns. > > Bob > > From: Bob Camp <kb...@n1k.or

Re: [time-nuts] Measuring phase with an HP 3456A?

uts do you assume I have? I don't think I can attach two 10MHz inputs to > a soundcard and expect anything useful. > > Bob > > > > From: Bob Camp <kb...@n1k.org> > To: Bob Stewart <b...@evoria.net>; Discussion of precise time and frequency > measurement

Re: [time-nuts] Prologix USB-GPIB Controller

Hi Like it or not, these days the volume purchases of IC’s are made in China. Volume buys have *always* been lower cost than normal distribution pricing. A > 10:1 ratio is not at all out of the question. If I bought 10,000,000 of a chip each month, I’d expect (and probably get) a very good

Re: [time-nuts] TimeLab

with a > clean sheet. I was intentionally not going down that road but more thinking > about practical setups with the stuff we have, or very small additions. > > Cheers, > Magnus > > On 10/09/2016 07:26 PM, Bob Camp wrote: >> Hi >> >> >>>

Re: [time-nuts] eLORAN on the air for 30 days

are using the system for various demonstrations >>> to government types. It is indeed Washingtons speed to resolution thats >>> taking the time. >>> So my crystal ball says nothing at all on what and when. >>> But that said the fact that its on for a month lets me

Re: [time-nuts] eLORAN on the air for 30 days

is neither practical or easy > to deploy. Then again, I'm biased in that regard. > > 26 Jan did some good, and upcoming leap-second comes very timely in that > regard. > > Cheers, > Magnus > > On 10/25/2016 09:53 PM, Bob Camp wrote: >> Hi >> >> Given th

Re: [time-nuts] eLORAN on the air for 30 days

t and when. >> But that said the fact that its on for a month lets me check some >> references. >> Regards >> Paul >> WB8TSL >> >> On Tue, Oct 25, 2016 at 7:33 AM, Bob Camp <kb...@n1k.org> wrote: >> >>> Hi >>> >>>

Re: [time-nuts] eLORAN on the air for 30 days

Hi > On Oct 25, 2016, at 7:30 PM, Magnus Danielson > wrote: > > Charles, > > On 10/26/2016 01:10 AM, Charles Steinmetz wrote: >> Magnus wrote: >> >>> It's interesting in that it's clearly not dead yet, rather the opposite. >> >> No, it's well and truly dead. Of

Re: [time-nuts] Opening an Isotemp OCXO

Hi Roughly 99.9% of all OCXO’s made go to large OEM customers. The percentage may actually be a bit higher than that. There are relatively few markets that “catalog” OCXO’s sell into. Inevitably the first thing that an OEM wants is some form of customization. A specific supply voltage, a

Re: [time-nuts] Opening an Isotemp OCXO

Hi If the OCXO was designed for a ~70 C upper end temperature spec, then a ~90C crystal would make sense. When you feed +12 into the oven control, you are increasing the effective gain of the control loop (it has more power). The cycling you see is the loop going into oscillation. It’s the

Re: [time-nuts] WWV receivers?

Hi Let’s see…. WWV (not WWVB) gets here via a variety of propagation mechanisms that vary over the day. According to NIST (who probably know :) that puts a random timing variation of ~1 ms on the signal. Since some modes get me a signal and others don’t, there is no real reason to assume it is

Re: [time-nuts] Difference in manufacturing for fundamental tone, 3rd, and 5th overtone crystals

Hi Crystals are highly optimized for the specific overtone they are intended to operate on. In fact, you can fiddle them to the point that they no longer have a “fundamental” response. Bob > On Oct 27, 2016, at 6:42 PM, Attila Kinali wrote: > > Moin, > > I have stumbled

Re: [time-nuts] Difference in manufacturing for fundamental tone, 3rd, and 5th overtone crystals

> wrote: > > Hi, > > Hmm, such fiddeling could maybe also apply to nearby alternative modes of the > crystals, even if I guess it would be harder to do meaningful dents on them. > > Cheers, > Magnus > > On 10/28/2016 01:50 AM, Bob Camp wrote: >> Hi >&

Re: [time-nuts] theoretical Allan Variance question

Hi Well, situation one: You have two perfect sources. Your measuring device is noiseless If your devices are in perfect sync, you get a series of zeros Your ADEV is zero Situation two: Same sources Noisy measuring device You get the standard deviation of the difference in measurements Your

Re: [time-nuts] Opening an Isotemp OCXO

ies, but given the right tools and employees... > > Bob > > From: Bob Camp <kb...@n1k.org> > To: pe...@reilley.com; Discussion of precise time and frequency measurement > <time-nuts@febo.com> > Sent: Friday, October 28, 2016 2:46 PM > Subject: Re: [time-nuts] Ope

Re: [time-nuts] Has anybody checked this? GPSDO in kit

Hi Any pole mount outdoor antenna with a gain in the 20 to 30 db range should be fine with any of these units. Cable loss can be an issue if it is getting the net gain down below 10 db (antenna gain - cable loss). The frequency is 1.5 GHz so a quick look at the standard tables should give you an

Re: [time-nuts] Thermal impact on OCXO

the past 3 or so days of > data collection to project the near-term behavior; where near-term is less > than 3 days into the future. > > Bob > > - > AE6RV.com > > GFS GPSDO list: > groups.yahoo.com/n

Re: [time-nuts] Thermal impact on OCXO

Hi > On Nov 7, 2016, at 12:45 PM, Chris Caudle wrote: > > On Mon, November 7, 2016 11:41 am, Chris Caudle wrote: >> On Mon, November 7, 2016 11:20 am, Bob Stewart wrote: >>> Either then OCXO is making up for the temperature change >>> by increasing the temperature >> >>

Re: [time-nuts] Thermal impact on OCXO

Hi Ok, You have a thermocouple junction at the + post on the DVM. You have one at the - post on the DVM. You have a junction at the + connection to the board. You have a junction at the - connection to the board. There are indeed more than that, but those four are pretty much a sure thing.

Re: [time-nuts] Man with too many clocks.

ere is a reason counters don't let you digitally > calibrate beyond that, the 10 MHz ref out on the rear panel would still be > out of cal. > > On Fri, Nov 4, 2016 at 1:48 PM, Bob Camp <kb...@n1k.org> wrote: > >> Hi >> >> The only practical way to set the 10

Re: [time-nuts] Thermal impact on OCXO

Hi You have a first order, second order and third order coefficient to the temperature rate dependance on a crystal. Since the second order term is a square, it does not care about the sign of the rate. Bob > On Nov 4, 2016, at 9:56 PM, Bob Stewart wrote: > > In the

Re: [time-nuts] Man with too many clocks.

HI If you use a good wire wound pot and run it off of and oscillator EFC source (not all have them), the temperature effect is pretty much zero. You are using the pot as a ratio device. A mechanical cap that is part of the heated region of the OCXO (the normal case) has already been taken

Re: [time-nuts] Thermal impact on OCXO

Hi Remember - most holdover specs also include a delta temperature (like 40 to 70C) during the holdover period …. Bob > On Nov 5, 2016, at 12:15 PM, Bob Stewart wrote: > > Hi Scott and Bob and others, > I keep telling myself that I won't get involved with the temperature

Re: [time-nuts] Need some wisdom from the cesium beam tube gurus out there

Hi I would bet that they started as you have with a low oven setting and cranked it up based on stability data. Once they got to that point, add a bit to have enough margin on the tube for it to last the rated life. Since there are multiple quantum “modes” the beam can get into, there may

Re: [time-nuts] How to get PPS from ublox mini-PCI GPS to APU2 SoC serial port for ntpd

Hi > On Nov 9, 2016, at 6:28 PM, Bob Stewart wrote: > > Tom, > How many times have people posted here, on time-nuts, not to trust the > trailing edge of a 1PPS pulse? The rest of the caution is : The leading edge is the one that is “on time” and the second edge is an

Re: [time-nuts] Thermal impact on OCXO

Hi > On Nov 5, 2016, at 10:43 PM, Bob Stewart <b...@evoria.net> wrote: > > Hi Scott, > D'oh. Thanks for the correction! Like I said, I don't do these calculations > often. > > If as Bob Camp implies, the aging isn't from the OXCO, then I'm a bit > stumped.

Re: [time-nuts] Thermal impact on OCXO

an just to temperature transients? > > Bob - > AE6RV.com > > GFS GPSDO list: > groups.yahoo.com/neo/groups/GFS-GPSDOs/info > > From: Bob Camp <kb...@n1k.org> > To: Bob Stewart <b...@evoria.net&g

Re: [time-nuts] Nutty time-nuttery with WWVB

Hi > On Nov 10, 2016, at 4:52 PM, Ruslan Nabioullin wrote: > > On 11/10/2016 07:18 AM, Peter Reilley wrote: >> I have a few of those "atomic" clocks that receive WWVB to set the time. >> However since I live on the east coast they may only pick up the signal >> once or

Re: [time-nuts] Need some wisdom from the cesium beam tube gurus out there

Hi > On Nov 11, 2016, at 8:02 AM, jimlux wrote: > > On 11/10/16 10:28 PM, Mike Millen wrote: >> It would work as well if you used a pair of regular copper wires to >> connect the meter to the thermocouple... >> >> The junctions created by all the new connections will

Re: [time-nuts] China Oscillator Alternative

> > See the text I linked to a few days ago. > > >> >> >> On 11/9/2016 7:18 PM, Perry Sandeen via time-nuts wrote: >>> List, >>> After all the problems that Bob Camp has noted with surplus OCXO's from >>> China, perhaps buyin

Re: [time-nuts] Nutty time-nuttery with WWVB

Hi This is worth repeating…. > On Nov 10, 2016, at 11:03 AM, Charles Steinmetz wrote: > > Peter wrote: > >> Could I implement my own personal WWVB transmitter that would >> be powerful enough to be picked up by the clocks in my house? >> * * * >> Has anyone

Re: [time-nuts] How to get PPS from ublox mini-PCI GPS to APU2 SoC serial port for ntpd

Hi Well, I have yet to test a gps module that does not have a *very* accurate pulse width out of it. Same with GPSDO’s. Yes, It’s something I look at. Bob > On Nov 10, 2016, at 10:22 AM, Chris Albertson > wrote: > > The problem here is "real world". Yes in theory

Re: [time-nuts] I love the smell of tantalum in the morning

Hi A *lot* depends on how many planes there are in that board. The weight of he copper also maters a bit. If there is enough thermal mass, you will need a pre-heat process. There are lots of ways to do it ranging from the kitchen oven to various “frame and lightbulb” setups and on into ever

Re: [time-nuts] Thermal impact on OCXO

--- > AE6RV.com > > GFS GPSDO list: > groups.yahoo.com/neo/groups/GFS-GPSDOs/info > > > From: Bob Camp <kb...@n1k.org> > To: Bob Stewart <b...@evoria.net> > Sent: Saturday, November 5, 2016 8:46 PM > Subject: Re: [tim

Re: [time-nuts] Thermal impact on OCXO

Hi 2^20 is roughly 1 ppm. It is about 5 uV on a 5V line or 2.5 uV on a 2.5 V EFC center. A DAC that does 100 ppm / C is a pretty typical part. 10 ppm / C is unusually good A “good” voltage reference might do 2 ppm / C A very typical room will swing around +/- 2C without much

Re: [time-nuts] Thermal impact on OCXO

; the process) there was enough off time to thoroughly insult the OCXO. > > Bob > > - > AE6RV.com > > GFS GPSDO list: > groups.yahoo.com/neo/groups/GFS-GPSDOs/info > > > From: Bob Camp <kb...@n1k.o

Re: [time-nuts] 1PPS to 32.768 khz

HI That approach would also work fine on a “internal clock” MCU. Scratch the need for a fancy timer. You may be down under 50 cents …. Bob > On Oct 19, 2016, at 7:15 PM, Mark Sims wrote: > > Here's another way to do it for a wall clock display... set up an >

Re: [time-nuts] 1PPS to 32.768 khz

Hi As has been already mentioned, a lot depends on what you have. The drop dead cheapest way to do it: Start with an MCU with an internal oscillator. There are *lots* to pick between. Which sort really does not matter. For example, I’ll use one that starts at 4 MHz. Divide the 4 MHz down to

Re: [time-nuts] 1PPS to 32.768 khz

Hi One problem with a PLL and a 1 Hz input are the values of components you get in the loop. The other issue is the cost of the VCXO that will get you to 32,768 KHz. The PLL as described by the OP would need the 1 pps divided by 2 with a lot of PLL chips. You now are locking 32768 to 0.5 Hz.

Re: [time-nuts] Anyone looking for HP 5060A parts/modules?

Hi My guess is that a “complete except for the tube” 5060A is a pretty common item. The tubes are basically an un-obtainable item (in good working order). Bob > On Oct 12, 2016, at 11:04 AM, Don Lewis wrote: > > Skip... > > Would there be enough parts to make one

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