Re: [time-nuts] Fluke monitor
In a message dated 04/06/2010 05:47:32 GMT Daylight Time, le...@wa5znu.org writes: fixed my fluke.l monitor. This evening I got mail today from Bob Mokia: The problem is too much volts on CPU (8051F330D). Must have diodes 1n4148 etc at D1 and D2. Drop cpu volts to 3.6volts. Maximum volts from data sheet is 4.2 volts. D1, D2, and D3 are zero-ohm SMT resistors in series from the 5V regulator output. They are visible from the CPU board edge. Without removing the CPU board from the display, I was able to remove D1 and tack a pair of 1N4148's in series from the D1 plus pad to D2, both right at the board edge. I left D2 and D3 in place. I made the leads as short as possible, but still had to bend the parts up a bit to fit it in the case. As soon as I plugged it in, it worked. It's been on about 15 minutes now with no problems. --- Hi Leigh Congratulations on getting your monitor fixed. That's great news and very interesting, many thanks for sharing it. Mine are still packed away but I'm getting closer to being up and running again so will check them over when I can and adjust as necessary. Marking the component positions D1, D2, D3 presumably implies that the designer of the PCB allowed for this from the start so raises the question, why wasn't it implemented as such? Measurements I made following the initial confusion over supply requirements did confirm that the display module will still function at 3.6 volts but I would have expected the contrast to require adjustment if the supply to that had also been dropped so perhaps the regulator output splits before the diodes. That might also explain also why the option to fit the diodes was given in the first place, instead of just using a lower output regulator. Perhaps the design of the original iCruze processor board was rather blindly copied, with variation where necessary to accomodate the different package and/or pin out of the 8051, but otherwise left the same and without due consideration given to the voltage requirements of the replacement processor.? Also of concern is the fact that your unit, and it appears some others too, did work as expected for quite a while before showing the symptoms you previously described. Those symptoms then being consistent, at least without dropping the supply voltage, suggests the possibility of some form of irreversible change, so I wonder if something in the processor itself, perhaps a protection device, might have been permanently damaged? regards Nigel GM8PZR ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Fluke monitor
Hi Gents, Just received a few hours ago my new Fluke monitor and just right now making the mods... I used 2SMD diode and the voltage on the CPU is 3,6 Volt. hopefully will work properly.. Will report later on any problem. Rgds Ernie. -Original Message- From: gandal...@aol.com To: time-nuts@febo.com Sent: Fri, Jun 4, 2010 11:57 am Subject: Re: [time-nuts] Fluke monitor In a message dated 04/06/2010 05:47:32 GMT Daylight Time, le...@wa5znu.org rites: fixed my fluke.l monitor. This evening I got mail today from Bob Mokia: The problem is too much volts on CPU (8051F330D). ust have diodes 1n4148 etc at D1 and D2. Drop cpu volts to 3.6volts. aximum volts from data sheet is 4.2 volts. D1, D2, and D3 are zero-ohm SMT resistors in series from the 5V egulator output. They are visible from the CPU board edge. Without emoving the CPU board from the display, I was able to remove D1 and ack a pair of 1N4148's in series from the D1 plus pad to D2, both right t the board edge. I left D2 and D3 in place. I made the leads as hort as possible, but still had to bend the parts up a bit to fit it in he case. As soon as I plugged it in, it worked. It's been on about 15 minutes ow with no problems. -- i Leigh ongratulations on getting your monitor fixed. hat's great news and very interesting, many thanks for sharing it. ine are still packed away but I'm getting closer to being up and running gain so will check them over when I can and adjust as necessary. arking the component positions D1, D2, D3 presumably implies that the esigner of the PCB allowed for this from the start so raises the question, hy wasn't it implemented as such? easurements I made following the initial confusion over supply equirements did confirm that the display module will still function at 3.6 olts but would have expected the contrast to require adjustment if the supply to hat had also been dropped so perhaps the regulator output splits before he diodes. hat might also explain also why the option to fit the diodes was given in he first place, instead of just using a lower output regulator. erhaps the design of the original iCruze processor board was rather lindly copied, with variation where necessary to accomodate the different ackage and/or pin out of the 8051, but otherwise left the same and without due consideration given to the voltage requirements of the replacement rocessor.? lso of concern is the fact that your unit, and it appears some others oo, did work as expected for quite a while before showing the symptoms you reviously described. hose symptoms then being consistent, at least without dropping the supply oltage, suggests the possibility of some form of irreversible change, so wonder if something in the processor itself, perhaps a protection device, ight have been permanently damaged? egards igel M8PZR __ ime-nuts mailing list -- time-nuts@febo.com o unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts nd follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS Sat Clock Data
Hi There have been hardware papers every few years showing this and that about the clocks. They obviously have access to some sort of database that lets them generate the data. I guess the database is off limits to civilians. Bob On Jun 4, 2010, at 1:10 AM, b...@lysator.liu.se wrote: Hi Bob, I have in the past watched presentations at ION on signal in space (SIS) accuracy for the GPS constellation. There was a steady improvement, with leaps between different SV (clock) generations. But also an improvements with adjustments in the ground segment, including adding more ground monitor sites. I am pretty sure there was also AVAR(?) plots for individual SVs maybe only clock types. One of the presentations was from Lookheed Martin where the new data was from II-RMs. http://www.ion.org/search/search_proceedings.cfm -- Björn Hi That's pretty close to what I'm looking for. The ideal would be to have variance vs a range of tau for each individual sat. If there's a way to get that from the NIST site, I've overlooked it. The whole constellation data vs a range of tau is a reasonable starting point. The thing I was surprised by was the range of performance of each sat as shown in the paper I mentioned. Thanks! Bob On Jun 3, 2010, at 9:54 PM, Brian Kirby wrote: I do not know if this is what your looking for, http://www.nist.gov/physlab/div847/grp40/gpsarchive.cfm follow the directions on the date You can look at individual SVN performance, etc. Bob Camp wrote: Hi In this paper: TOTAL HADAMARD VARIANCE: APPLICATION TO CLOCK STEERING BY KALMAN FILTERING by Dave Howe , Ron Beard , Chuck Greenhall , Franc ̧ois Vernotte and Bill Riley http://tf.nist.gov/general/pdf/1459.pdf Figure 2 actually refers to: Navstar Quarterly Report 00-3, Space Application Branch, NRL, Wash D.C. 20 July 2000. The report apparently describes the level of variance on the various GPS satellites versus tau for the first half of 2000. Bottom line appears to be that 5x10^-13 is about as good as it gets out to 20 day tau unless you can pick your sats. Obviously this data is a bit dated. Is this data updated on a regular basis? Is it published somewhere? Can one get a look at it without risking a long term stay in Federal prison? It certainly would be useful to those trying to tweak GPSDO's. Bob ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Lady Heather's D. O. program
On 4 June 2010 17:33, John Miles jmi...@pop.net wrote: Yep, I'm in charge of maximizing CPU utilization. :) ROFL Steve -- john, KE5FX -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com]on Behalf Of Had Sent: Thursday, June 03, 2010 7:58 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Lady Heather's D. O. program I think that it is important to remember that along with Mark, John Miles, KE5FX, has had a lot to do with the more recent implementations of LH Had K7MLR At 08:27 PM 6/2/2010, you wrote: I second that! At 03-06-10, you wrote: Hello Time nuts and good evening; I have been using this program with my TB. for a while now and just wanted to thank Mark Sims who I believe is responsible for his marvelous work of art. -- Raj, VU2ZAP Bangalore, India. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. A fine is a tax for doing wrong. A tax is a fine for doing well. Peter Cooper, of Fermi Lab, says, Every experimentalist knows that the apparatus, or at least your understanding of it, is always at fault until demonstrated otherwise. He also says, Nature is really unmoved by what I, or anyone else, believes. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- Steve Rooke - ZL3TUV G8KVD The only reason for time is so that everything doesn't happen at once. - Einstein ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Dual Frequency GPS receivers
Hi, The civilians are also used by the timing laboratories. Both antennas and receivers float by on the eRiver from time to time at very reasonable prices. These are more often than Oncores available with a built in (tight) PLL letting you lock the local GPS recevier clock to your freq standard. -- Björn Hi Dual / tripple frequency comes in two basic flavors civilian and military. The civilian gear is aimed at the survey market and usually incorporates stuff like carrier phase. You can indeed get better time out of an expensive carrier phase receiver and it's associated antenna (also expensive). On a dollars spend per fraction of a ns gained - probably not worth the money. Bob On Jun 4, 2010, at 6:13 AM, Martyn Smith wrote: Hello, Is anyone using dual or triple frequency GPS receivers? Are there any advantages in relation to the quality of the 1 pps output? Best Regards Martyn ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Notes on tight-PLL performance versus TSC 5120A
On 4 June 2010 08:32, Charles P. Steinmetz charles_steinm...@lavabit.com wrote: If I may be allowed to summarize, it appears that Warren and Bruce agree that integration is necessary to produce true ADEV results. Warren asserts that the low-pass filtering his method uses is close enough to integration to provide a useful approximation to ADEV, while Bruce disagrees. So, the remaining points of contention seem to be: 1. How close can a LPF implementation come to integration in ADEV calculations, and Well, Warren uses two stages of integration. There has already been talk of the simple R/C filter in the feedback loop. Unless my education in electronics was completely wrong, the series R/C circuit forms a simple LPF and is an integrator (assuming that the resistor is in series with the input and the capacitor is in parallel with the output). See http://en.wikipedia.org/wiki/Integrator_circuit, http://en.wikipedia.org/wiki/RC_filter. Sorry these are not academic papers but if you spot something wrong please feel free to edit them appropriately. This first stage of integration is set at a much wider frequency than tau0 and forms the PLL-loop filter allowing it to track the FAST changes of a noisy unknown oscillator. That last bit is very important and something some previous attempts at this method failed to resolve. Now there is a noisy control voltage on the reference oscillator and it is absolutely no good trying to make a single measurement at tau0 because the settling time of the filter has not been constrained to it so it will not give an integrated mean value. This where the second stage of integration comes in which is the oversampling which takes a number of readings during tau0 (please correct me if I have the terminology wrong here) which are then averaged to give a mean, integrated, value of the control voltage for tau0. So why two stages, look closely above, until the idea of oversampling was tried, the PLL-loop filter had to have a settling time, IE. cutoff frequency, equal to tau0 so that the measurement at tau0 reflected the mean, average, integrated, value for that tau0 period. But if a filter with that sort of cutoff is used then the reference oscillator is not able to track noise on the unknown oscillator at all and it would give results for things like flicker noise, random walk, etc, which were lower than the actual values. Now have a look at the top end of John's graphs where there is a divergence. 2. How close to true ADEV is good enough? well, considering we have integrated frequency measurements at tau0 intervals, there is little wonder that it correlates closely to ADEV because that's exactly what it is. I humbly submit that trading insults has become too dreary for words, and that neither Warren nor Bruce will ever convince the other on the latter point. Well, I've been on this list long enough to know that Bruce will always resort to that sort of behaviour when he is boxed into a corner or cannot get his point of view accepted. Anyone who speaks up against him is usually put in their place. This saga has come about because someone dared to challenge him so we have been subjected to his tantrums. I thus humbly suggest (nay, plead) that the discussion be re-focused on the two points above in a just the facts, ma'am manner. One can certainly characterize mathematically the differences between integration and LP filtering, and predict the differential effect of various LPF implementations given various statistical noise distributions. If one is willing to agree that certain models of noise distributions characterize reasonably accurately the performance of the oscillators that interest us, one can calculate the expected magnitudes of the departures from true ADEV exhibited by the LPF method. Each person can then conclude for him- or herself whether this is good enough for his or her purposes. Indeed, careful analysis of this sort should assist in minimizing the departures by suggesting optimal LPF implementations. Ask yourself what is the difference between a simple R/C LPF and integration, what is integration in fact. What is the difference between an electronic LPF and an integrator designed in electronics. I think we are getting hung up between the mathematical term integration and the electrical term. Although I should say that of course ADEV is a mathematical derivation taking frequency data and finding the averages of various positional averages. Whether the frequency data is provided as the inverse of the measured period of the unknown oscillator or the voltage reading of a fancy VCO (ref osc), makes no difference, providing that each data point is accurately represented. In terms of optimal LPF implementations as I see mentioned here, this is the trap that previous people trying to use the tight-PLL method have fallen into. An optimal LPF will give a very accurate average value of the frequency for each tau0 point but only at the
Re: [time-nuts] Notes on tight-PLL performance versus TSC 5120A
On 4 June 2010 08:13, Bruce Griffiths bruce.griffi...@xtra.co.nz wrote: So you say but it is producing a result that seems to be VERY interesting. To adopt an attitude where everything has to be done a specific way totally misses out on innovation. You cant arbitrarily change the equivalent filter and expect to get the same results. Unfortunately the people who have tried to use this method before, despite all the letters after their names, had a great deal of problems with the LPF design as it had two constraints which were totally opposed to each other. They needed a filter which accurately settled at tau0 time to reflect the fundamental frequency and at the same time, the filter had to have enough bandwidth to allow the reference oscillator to track the unknown oscillators noise. That's about as easy and as much fun as trying to kick a dead whale up a beach. A way around this is for the PLL-loop to have a wide bandwidth so that it accurately tracks the two oscillators together and then to oversample and average the results per tau0 to get accurate data. In the Renault factory when they made the first 2CV motor car they were having trouble assembling it as they could not get some of the body parts to fit together. One of the mechanics gave the item a good kick with his boot and the item popped into place. This method was then adopted for the assembly of that vehicle as it worked, it was not high-tech but it worked. You could say that this was not the optimum method to build a car and send it all back to the drawing board to sort it out at a vast cost in re-engineering or you can stick with what works. Irrelevant analogy as the adopted method doesnt conflict with the requirements of any accepted physical theory. Wow Bruce! Where do you come up with these pompous statements. If you failed to understand the point I was trying to make here then perhaps I'm wasting my time trying to explain all this to you. That paper is irrelevant for the method that Warren has chosen. If you had read and understood the paper you wouldnt believe that. You don't need to design an optimal filter because this method does not hinge on that as a critical component unlike the method in the paper you cited. Now perhaps you should read what Warren and I have written so that you might just understand why this is so. Really! This is not the case as the loop bandwidth of significantly wider than the oversampling rate and this rate is significantly faster than the minimum Tau sampling rate. Why is there any need to use any appropriate signal processing algorithms with such an elegantly simple improvement on the NIST design. I find it hard to understand what you don't understand here. You need to read up on the definition of AVAR, ADEV etc and understand that it requires average frequency measures or phase differences. Integration (in hardware or software) is required to do this. Warrens hardware merely implements the low pass filter required to limit the contribution of white phase noise etc to ADEV. And that is where you have totally lost the plot! Warrens filter does not limit the effects of noise to ADEV, whereas the optimal filter design you have spoken of and cited in the paper does limit this. Warren's design produces accurate frequency measurement because the bandwidth of the PLL-loop is very much wider than 1 / tau0 so the effects of noise are allowed to keep the two oscillators in sync. Previous attempts at this have tried to make the loop filter time constant fit the sampling frequency and these attempts have managed to limit the contribution of noise to the ADEV measurement. The filter does not come into it as Warren has not designed the filter to have a Tc equivalent to the Tau sampling rate. Now the penny has dropped and I can see where you are going wrong here. The filtering here is done simply by oversampling and averaging the results of the measurements over the minimum Tau period. Excellent paper but far too full of theoretical math for my liking these days. If you don't follow the paper, how is it that you feel that you know sufficient to make a useful contribution to the discussion? The paper explicitly covers the tight PLL technique where a sequence of frequency samples are taken and shows how to produce valid ADEV measures from these samples. It also provides a formula that can be used to predict the consequences of inappropriate signal processing. OK, so I don't have a string of letters after my name but it doesn't take half a brain to understand this Bruce. Now I use that term almost literally as a couple of members on this list know what I'm getting at at least. Anyway, I digress and shall use whatever brain I have left to try and get this point over. You seem to hold up this cited paper as one of the Dead See Scrolls and as such being the last word on the subject. What makes you think that this paper is all that there is to the tight-PLL method? How
Re: [time-nuts] A philosophy of science view on the tight pll discussion
I for one, have grown tired of the ad-hominem anti-intellectual attacks. This is supposed to be about science and engineering, not words. Therefore, I'd like to see analysis. As Lord Kelvin put it: In physical science the first essential step in the direction of learning any subject is to find principles of numerical reckoning and practicable methods for measuring some quality connected with it. I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind; it may be the beginning of knowledge, but you have scarcely in your thoughts advanced to the state of Science, whatever the matter may be. What I want to see in the future are equations. Please use LaTex notation so we all can see what's going on. Until that happens, it's all just fuzzy semantics --- neither science nor engineering. If you make a claim, support it with equations. If you can't, then don't make the claim. It's that simple. On Fri, Jun 4, 2010 at 11:15 AM, Steve Rooke sar10...@gmail.com wrote: On 4 June 2010 07:11, Didier Juges did...@cox.net wrote: WarrenS warrensjmail-...@yahoo.com wrote: Ulrich posted a bunch of logic stuff, some of which I did not understand. but I do think he missed the main point I personally think Warren missed the point entirely, but it's just my opinion. This statement is a good summary of what has been going on. You cannot dismiss something that you do not understand, yet that's what you have been trying to do for a long time now. I'm not sure that that the point was made clear or if even there was a point to this unless you are taking a specific side. Examining things:- The physicist obviously had a a good general education which included biology, genealogy, logic and nursery rhymes. He deduced correctly that the likelihood of a black sheep occurring naturally via a second occurrence of natural selection and that the black coat was due to a genetic anomaly which indicated that it was very likely that the gene for a black coat was in the sheep that were close to the this place which meant that it was most likely that black sheep were in Germany. He dismissed the idea that the farmer had just shipped the black sheep into Germany because his daughter liked nursery rhymes as he logically knew that farmers never do anything that costs them anything only things that make them money. He remembered the age old saying, you'll never see a farmer on a bike. He therefore deduced that this was proof that there are black sheep in Germany. The mathematician was obviously deeply engrossed in his complex mathematics education which took up most of his time and didn't care to much for other subjects. He was a romantic and remembered his mother saying all the nursery rhymes to him when he was young. Being that he spent so much of his time in his own head, he had no real idea of life outside that and really had a childlike attitude to things in the outside World. When he saw the farm and the black sheep he obviously thought of a happy farming family and deduced that the really nice farmer had gone out of his way to find the only black sheep in Europe so that he could make his daughter happy. It did not cross his mind that a black sheep had anything to do with genetics but he had enough sense to know that animals had the same colours on each side, after all the zebra in his little farm set he had as a child had stripes on both sides. That was logical to him so he deduced that there was at least one black sheep in Germany. The logician ate, drank and slept pure logic all his life. As far as he was concerned, the World was all binary, true and false, black and white. To him everything in the World could be explained by logic and everything was logical. As logic explained everything he had no time for any other disciplines as they were superfluous, after all, everything could be explained by logic. Having never ventured from his deep dark dungeon with black and white walls he was intrigued to see the World outside. He made no assumptions on what he saw and always understood that everything could be explained by logic. It was therefore completely logical for him to deduce that what he was looking at was the black side of a sheep whereas he could not make a deduction on the other sheep as they were all facing the other way. So his deduction that there was at least one sheep with one black sheep was perfectly logical to him and he went back to enjoying his train journey. And the moral of the story is, you only see the World with eyes that are open and been trained to see what you have experience in. To step out of the square you are standing in can be very hard but the best approach to life is to adopt that of a child and enjoy all the wonderment around you.
Re: [time-nuts] Fluke Thunderbolt Monitor Revisited
Hi: I've added a photo of the component side of the 8051 PCB at: http://www.prc68.com/I/ThunderBolt.shtml#8051PCB J1-2 is connected directly to pin 6 of the uC which is also connected to the output of the 78D05 regulator. Have Fun, Brooke Clarke http://www.PRC68.com gandal...@aol.com wrote: Hi All As there still seemed to be unanswered questions regarding the circuitry of these I've separated the two PCBs from one of mine to determine exactly what is going on. Whether or not the regulator circuit is based in any way on the iCruze original processor board I don't know but it's now quite clear that the processor circuitry itself is an amost exact copy of Didier's version using the 20 pin DIP C8051F330 processor. The only differences I've found so far are the values of the resistor in the programming interface and those on the RS232 input but the layout itself looks to be identical. I'll go over it more thoroughly later and produce a complete schematic. Didier's original schematic, which includes the three series diodes for use with a 5 volt supply, can be found here . _http://www.ko4bb.com/Timing/GPSMonitor/Schematic-3.png_ (http://www.ko4bb.com/Timing/GPSMonitor/Schematic-3.png) As commented by Leigh earlier, all the diode positions on the PCB are occupied by zero ohm links so I think it's reasonable to assume this is probably universal and ALL monitors are likely to need modifying to keep the processor supply voltage at a safe level. The absolute maximum rated supply voltage is 4.2 volts, IO port and RST pins are indicated as tolerating up to 5 volts, but the specified operating supply voltage range is 2.7 to 3.6 volts so I would recommend fitting all three diodes as per Didier's original circuit rather than just two. The supply to the display is taken directly from the output of the regulator and not via the diodes. For anyone wanting to avoid hardware modification another option would be to run the unit from an external 5 volt supply, as was originally suggested, and let the onboard regulator just act as a dropper. With a 5 volt supply the output voltage from the regulator is 3.6 volts but of course it isn't regulating and the supply to the display is also reduced. I have found that my display at least will run ok at 3.6 volts but the contrast pot may need adjusting. However, if this route is followed there's little room for error and it's important to make sure the external supply is kept below 5.6 volts otherwise the processor supply will again exceed 4.2 volts. Fitting the diodes is a once and for all solution and is certainly the preferred option. regards Nigel GM8PZR ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] A philosophy of science view on the tight pll discussion
So a tree is a physical object, its workings can be understood by botanical analysis, but just how do you quantify its beauty in numbers or equations then? And before you try to wriggle out of this, the beauty of a tree is a physical artefact because it imbues a reaction in the viewer. 2+3*6=20 3^3^3=? Steve On 5 June 2010 03:48, Mark Kahrs mark.ka...@gmail.com wrote: I for one, have grown tired of the ad-hominem anti-intellectual attacks. This is supposed to be about science and engineering, not words. Therefore, I'd like to see analysis. As Lord Kelvin put it: In physical science the first essential step in the direction of learning any subject is to find principles of numerical reckoning and practicable methods for measuring some quality connected with it. I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind; it may be the beginning of knowledge, but you have scarcely in your thoughts advanced to the state of Science, whatever the matter may be. What I want to see in the future are equations. Please use LaTex notation so we all can see what's going on. Until that happens, it's all just fuzzy semantics --- neither science nor engineering. If you make a claim, support it with equations. If you can't, then don't make the claim. It's that simple. On Fri, Jun 4, 2010 at 11:15 AM, Steve Rooke sar10...@gmail.com wrote: On 4 June 2010 07:11, Didier Juges did...@cox.net wrote: WarrenS warrensjmail-...@yahoo.com wrote: Ulrich posted a bunch of logic stuff, some of which I did not understand. but I do think he missed the main point I personally think Warren missed the point entirely, but it's just my opinion. This statement is a good summary of what has been going on. You cannot dismiss something that you do not understand, yet that's what you have been trying to do for a long time now. I'm not sure that that the point was made clear or if even there was a point to this unless you are taking a specific side. Examining things:- The physicist obviously had a a good general education which included biology, genealogy, logic and nursery rhymes. He deduced correctly that the likelihood of a black sheep occurring naturally via a second occurrence of natural selection and that the black coat was due to a genetic anomaly which indicated that it was very likely that the gene for a black coat was in the sheep that were close to the this place which meant that it was most likely that black sheep were in Germany. He dismissed the idea that the farmer had just shipped the black sheep into Germany because his daughter liked nursery rhymes as he logically knew that farmers never do anything that costs them anything only things that make them money. He remembered the age old saying, you'll never see a farmer on a bike. He therefore deduced that this was proof that there are black sheep in Germany. The mathematician was obviously deeply engrossed in his complex mathematics education which took up most of his time and didn't care to much for other subjects. He was a romantic and remembered his mother saying all the nursery rhymes to him when he was young. Being that he spent so much of his time in his own head, he had no real idea of life outside that and really had a childlike attitude to things in the outside World. When he saw the farm and the black sheep he obviously thought of a happy farming family and deduced that the really nice farmer had gone out of his way to find the only black sheep in Europe so that he could make his daughter happy. It did not cross his mind that a black sheep had anything to do with genetics but he had enough sense to know that animals had the same colours on each side, after all the zebra in his little farm set he had as a child had stripes on both sides. That was logical to him so he deduced that there was at least one black sheep in Germany. The logician ate, drank and slept pure logic all his life. As far as he was concerned, the World was all binary, true and false, black and white. To him everything in the World could be explained by logic and everything was logical. As logic explained everything he had no time for any other disciplines as they were superfluous, after all, everything could be explained by logic. Having never ventured from his deep dark dungeon with black and white walls he was intrigued to see the World outside. He made no assumptions on what he saw and always understood that everything could be explained by logic. It was therefore completely logical for him to deduce that what he was looking at was the black side of a sheep whereas he could not make a deduction on the other sheep as they were all facing the other way. So his deduction that there was at least one sheep with one
Re: [time-nuts] Fluke Thunderbolt Monitor Revisited
In a message dated 04/06/2010 16:53:36 GMT Daylight Time, bro...@pacific.net writes: I've added a photo of the component side of the 8051 PCB at: http://www.prc68.com/I/ThunderBolt.shtml#8051PCB J1-2 is connected directly to pin 6 of the uC which is also connected to the output of the 78D05 regulator. Yes it seems to be, but if you check you'll find that it's not actually a direct connection. J1-2 and pin 6 of the uC are connected together and then connected to the bottom of what's marked as D3 in your photo. D1, 2 and 3 are in series between the regulator output and the processor pin 6 but it's these that have been replaced with zero ohm links so metering will show a direct connection. It's these links need to be removed and replaced with diodes as per Didier's original schematic. regards Nigel GM8PZR ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Looking for Manual for Datachron 3650-133 - Help Please?
Hi All: New user / first post. I just picked up a Datachron 3650-133 GPS Synchronized Time Code Generator to use as a timebase for my amateur astronomy observatory. I've looked all over for a PDF of the manual and can't find anything. Does anyone have a copy (paper or PDF) that they could send me a copy of? Many thanks. Peace blessings, Donn Williams / do...@opticalscientific.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Fluke T-Bolt Monitor Dumb Question
Is that Daughter-Board soldered in or plugged in ? It looks like it's plugged into the connector but I can't get it to budge and I really don't want to apply too much force and wind up breaking it. Thanks, Dick, W1KSZ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Fluke T-Bolt Monitor Dumb Question
Is that Daughter-Board soldered in or plugged in ? It looks like it's plugged into the connector but I can't get it to budge and I really don't want to apply too much force and wind up breaking it. Thanks, Dick, W1KSZ I believe it's soldered. I was able to do my mod using through-hold diodes without moving it. I just used a small-tipped soldering iron to remove one of the existing SMT diodes, tinned the two pads a bit (one empty going to V+, the other going to the still-present zero-ohm resistor) and tacked the new parts on. Leigh/WA5ZNU ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Fluke T-Bolt Monitor Dumb Question
In a message dated 04/06/2010 18:34:23 GMT Daylight Time, w1...@earthlink.net writes: Is that Daughter-Board soldered in or plugged in ? It looks like it's plugged into the connector but I can't get it to budge and I really don't want to apply too much force and wind up breaking it. -- Hi Dick Leigh's right, it's soldered. What might look like a plug is just the plastic separators on the pin strips. If, as Leigh did, you can manage without removing the daughter board that should make life a lot easier. I originally tried to remove mine by cutting the pins, reason being it's much easier to unsolder individual pins, but the PCB is a bit fragile, perhaps solder hadn't flowed properly through the plated holes, and the wedging effect of even fine cutter blades was enough to push one of the pins up and take the through plating with it. After that, as my Pace kit is boxed up right now, I resorted to flooding between the pins with molten solder and removing it that way. regards Nigel GM8PZR ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Notes on tight-PLL performance versus TSC 5120A
Steve Rooke wrote: On 4 June 2010 08:32, Charles P. Steinmetz charles_steinm...@lavabit.com wrote: If I may be allowed to summarize, it appears that Warren and Bruce agree that integration is necessary to produce true ADEV results. Warren asserts that the low-pass filtering his method uses is close enough to integration to provide a useful approximation to ADEV, while Bruce disagrees. So, the remaining points of contention seem to be: 1. How close can a LPF implementation come to integration in ADEV calculations, and Well, Warren uses two stages of integration. There has already been talk of the simple R/C filter in the feedback loop. Unless my education in electronics was completely wrong, the series R/C circuit forms a simple LPF and is an integrator (assuming that the resistor is in series with the input and the capacitor is in parallel with the output). See http://en.wikipedia.org/wiki/Integrator_circuit, http://en.wikipedia.org/wiki/RC_filter. Sorry these are not academic papers but if you spot something wrong please feel free to edit them appropriately. This first stage of integration is set at a much wider frequency than tau0 and forms the PLL-loop filter allowing it to track the FAST changes of a noisy unknown oscillator. That last bit is very important and something some previous attempts at this method failed to resolve. A cascaded low pass filter and and a finite time interval integrator are required. A single RC LP filter can't approximate this. Its either a low pass filter or a crude approximation to an integrator not both. Now there is a noisy control voltage on the reference oscillator and it is absolutely no good trying to make a single measurement at tau0 because the settling time of the filter has not been constrained to it so it will not give an integrated mean value. This where the second stage of integration comes in which is the oversampling which takes a number of readings during tau0 (please correct me if I have the terminology wrong here) which are then averaged to give a mean, integrated, value of the control voltage for tau0. Speculative nonsense sampling by itself integrates nothing unless one uses an integrator to do the sampling. Even when the finite bandwidth of the sampler is taken into account the equivalent averaging time will be too short and not under user control. However the samples (if the sampling rate is sufficiently large) contain sufficient information for the required finite time integrator output values (or frequency averages) to be calculated. A simple rectangular integration approximation may not be sufficient in all cases. The sampling process actually tends to whiten the sampled phase noise spectrum. The amount of false white phase noise contributed by the sampling decreases as the sampling rate increases. A simple RC low pass filter may not be a a particularly good choice in this regard. So why two stages, look closely above, until the idea of oversampling was tried, the PLL-loop filter had to have a settling time, IE. cutoff frequency, equal to tau0 so that the measurement at tau0 reflected the mean, average, integrated, value for that tau0 period. But if a filter with that sort of cutoff is used then the reference oscillator is not able to track noise on the unknown oscillator at all and it would give results for things like flicker noise, random walk, etc, which were lower than the actual values. Now have a look at the top end of John's graphs where there is a divergence. The divergence at the top end of the graphs should be treated with extreme caution one needs to know the size of the associated error bars to be able to make statistically meaningful conclusions. In general the error bars tend to be large in this region. 2. How close to true ADEV is good enough? well, considering we have integrated frequency measurements at tau0 intervals, there is little wonder that it correlates closely to ADEV because that's exactly what it is. This cannot be so for each and every signal source if the weighting function (equivalent filter) doesn't closely match that used in the definition of AVAR. Without the integration/averaging the equivalent filter closely match the required filter at all frequencies. I humbly submit that trading insults has become too dreary for words, and that neither Warren nor Bruce will ever convince the other on the latter point. Well, I've been on this list long enough to know that Bruce will always resort to that sort of behaviour when he is boxed into a corner or cannot get his point of view accepted. Anyone who speaks up against him is usually put in their place. This saga has come about because someone dared to challenge him so we have been subjected to his tantrums. The saga originated because of the wildly inaccurate claims and very woolly explanation as to what signal processing was used. A few equations and a circuit diagram or 2 would have
Re: [time-nuts] GPS Sat Clock Data
In message 1576163c-fa59-40b3-808b-3d55df587...@rtty.us, Bob Camp writes: There have been hardware papers every few years showing this and that about the clocks. They obviously have access to some sort of database that lets them generate the data. I guess the database is off limits to civilians. Signal In Space quality is monitored using some of the low-orbit assets. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] A philosophy of science view on the tight pll discussion
This out-of-control thread has been a total waste of bandwidth for some time now. I feel that I should be embarrassed for some of the posters here because they appear to have no sense of shame. this thread reminds me of a Robert Frost poem about choices that isn't any more off topic than some of the other replies. -Arthur Fire and Ice Some say the world will end in fire, Some say in ice. From what I've tasted of desire I hold with those who favor fire. But if it had to perish twice, I think I know enough of hate To say that for destruction ice Is also great And would suffice. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Tight PLL method. Is it good enough?
I am a relative outsider to this fine group. I mostly just read the posts. I have learned a lot since I have subscribed. So, I don't have a dog in the fight over whether the tight PLL method is all Warren says it is. I can understand that Warren has researched this method, discovered its weakness and made advancements to compensate. He has tested it against a well known and respected piece of commercial gear and found good, though not perfect agreement. An achievement to be proud of. Bruce has also researched this method and sees that it has weaknesses. Some of which he feels Warren has not addressed. He is frustrated because Warren won't agree that there are problems with this method. As someone who merely wants to test some oscillators, I am mainly interested in finding components I can buy and assemble into something I can have a modicum of confidence in. I was looking at doing a DMTD setup because I have most of the necessary components. But Warren has gotten my attention. By testing it against a piece of commercial equipment, he has gotten me to believe that if I build a similar setup, I can achieve similar results. The interesting thing is that his setup is relatively simple. I could probably duplicate it pretty closely. Is it perfect? Probably not. Would it do what I need done? Probably so. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Tight PLL method. Is it good enough?
Hi What do you want to test? What do you want to do with the results? What are you going to compare them against? What range of measurements are you interested in? The DMTD will look at two atomic clocks on the same frequency and the reference drops out in the processing. Is that important to you? Do you have / need to have a method of testing the tester? Lots of what if's that need to be considered. Bob On Jun 4, 2010, at 5:48 PM, John Green wrote: I am a relative outsider to this fine group. I mostly just read the posts. I have learned a lot since I have subscribed. So, I don't have a dog in the fight over whether the tight PLL method is all Warren says it is. I can understand that Warren has researched this method, discovered its weakness and made advancements to compensate. He has tested it against a well known and respected piece of commercial gear and found good, though not perfect agreement. An achievement to be proud of. Bruce has also researched this method and sees that it has weaknesses. Some of which he feels Warren has not addressed. He is frustrated because Warren won't agree that there are problems with this method. As someone who merely wants to test some oscillators, I am mainly interested in finding components I can buy and assemble into something I can have a modicum of confidence in. I was looking at doing a DMTD setup because I have most of the necessary components. But Warren has gotten my attention. By testing it against a piece of commercial equipment, he has gotten me to believe that if I build a similar setup, I can achieve similar results. The interesting thing is that his setup is relatively simple. I could probably duplicate it pretty closely. Is it perfect? Probably not. Would it do what I need done? Probably so. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Small DMTD System
Time-Nuts, There has been much discussion on this list about methods of measuring short-term stability. I wanted to make the list aware of a new paper describing a small DMTD system. The system was developed by William Riley, author of STABLE32, and is described in detail with schematics and test results at: http://www.wriley.com/A%20Small%20DMTD%20System.pdf Richard ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Tight-PLL - YOU DON'T NEED TO READ IT IF YOUR FED-UP WITH THE THREAD SO HIT DELETE NOW!
I think I have found the source of the integration issue. I've spent some considerable time ploughing through as many sources of descriptions on ADEV, AVAR and the tight-PLL method. I've even tried looking for the infamous finite time interval integrator which seems to be highly notable by it's complete absence on Google. Well, eventually the answer struck me directly in the eye, the source of the integrate issue comes directly down to the original paper that Warren posted a link for:- D. Tight phase lock loop method The second type of phase lock loop method (shown in figure 1.7) is essentially the same as the first in figure 1.6 except that in this case the loop is in a tight phase lock condition; i.e., the response time of the loop is much shorter than the sample times of interest--typically a few milliseconds. In such a case, the phase fluctuations are being integrated so that the voltage output is proportional to the frequency fluctuations between the two oscillators and is no longer proportional to the phase fluctuations (for sample times longer than the response time of the loop). A bias box is used to adjust the voltage on the varicap to a tuning point that is fairly linear and of a reasonable value. The voltage fluctuations prior to the bias box (biased slightly away from zero) may be fed to a voltage to frequency converter which in turn is fed to a frequency counter where one may read out the frequency fluctuations with great amplification of the instabilities between this pair of oscillators. The frequency counter data are logged with a data logging device. The coefficient of the varicap and the coefficient of the voltage to frequency converter are used to determine the fractional frequency fluctuations, yi, between the oscillators, where i denotes the ith measurement as shown in figure 1.7. It is not difficult to achieve a sensitivity of a part in 1014 per Hz resolution of the frequency counter, so one has excellent precision capabilities with this system. http://tf.nist.gov/phase/Properties/one.htm The relevant section here is the response time of the loop is much shorter than the sample times of interest--typically a few milliseconds. In such a case, the phase fluctuations are being integrated so that the voltage output is proportional to the frequency fluctuations. So what this says is that by incorporating a PLL-loop filter that has a B/W much wider than the sample time, the phase fluctuations are integrated into the reference oscillator such that the control voltage of the tight-PLL now reads frequency which is unlike the loose-PLL which directly records the phase relationship between the oscillators. So the term integrated here is used a verb and not a noun, therefore it is an intrinsic function of the design not a separate process. Steve -- Steve Rooke - ZL3TUV G8KVD The only reason for time is so that everything doesn't happen at once. - Einstein ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
