[ntp:questions] What level of timesynch error is typical onWinXP?

David L. Mills mills at udel.edu
Mon Nov 8 05:14:54 UTC 2010


Dave,

Thanks for the test. I verified the same thing. Note that the measured 
offset at the end of the frequency measurement phase was very small, so 
the net frequency measurement should be the same as Solaris. Obviously, 
FreeBSD is doing something very different than Solaris. I suspect Linux 
is doing something completely different as well. At this point I am 
prepared to abandon the mission entirely, as I don't want to get bogged 
down with the specifics of each idiosyncratic operating system. 
Accordingly, I will back out all the changes and revert to the bad old 
ugly algorithms.

Dave

Dave Hart wrote:

>I regret to report ntpd 4.2.7p79, with the freq_mode fix, is still
>unable to estimate the frequency on the FreeBSD 6.4 test machine.  I
>repeated yesterday's tests after updating ntpd, still using the daemon
>loop and four sources with iburst and maxpoll 6.
>
>55507 47027.172 0.000131624 80.505 0.000295904 0.003852 6
>
>This is the last loopstats line from 4.2.7p78, after it had settled
>from yesterday's tests, showing the accurate frequency.
>
>55507 47305.668 0.116321337 0.000 0.041125803 0.000000 6
>55507 47309.670 0.102448652 0.000 0.038469785 0.000000 6
>55507 47309.670 0.102448652 0.000 0.035985748 0.000000 6
>55507 47366.669 0.016771582 0.000 0.034228017 0.000000 6
>55507 47431.669 0.002129784 0.000 0.033512148 0.000000 6
>55507 47432.668 0.002063228 0.000 0.033151910 0.000000 6
>55507 47499.668 0.000245885 0.000 0.033268284 0.000000 6
>55507 47568.668 0.000027500 0.000 0.032732507 0.000000 6
>55507 47634.669 0.091580060 278.349 0.031843464 0.000000 6
>55507 47700.669 0.087433242 278.349 0.029822893 0.000000 6
>55507 47710.669 0.066283980 278.349 0.028881495 0.000000 6
>55507 47769.669 0.052348797 278.349 0.027461734 0.000000 6
>55507 47779.669 0.038045135 278.349 0.026181154 0.000000 6
>55507 47836.669 0.024174098 278.349 0.024976427 0.000000 6
>55507 47845.669 0.009864700 278.349 0.023904791 0.000000 6
>55507 47905.669 -0.001928639 278.349 0.022746308 0.000000 6
>55507 47913.669 -0.012783326 278.349 0.021620551 0.000000 6
>55507 47973.668 -0.014912826 278.295 0.020238183 0.018856 6
>55507 48249.669 -0.023350333 277.911 0.019164681 0.136952 6
>55507 48379.669 -0.044163258 277.569 0.019378379 0.176208 6
>55507 48446.668 -0.063716048 277.314 0.019400266 0.187780 6
>55507 48518.669 -0.083934245 276.954 0.019504384 0.216961 6
>55507 48655.668 -0.100637719 276.132 0.019176655 0.354409 6
>55507 48841.669 -0.122561216 274.774 0.019541138 0.583684 6
>55507 49251.501 0.000000000 274.774 0.000001907 0.545987 6
>55507 49258.500 -0.019540127 274.766 0.006908478 0.510732 6
>55507 49467.500 -0.021120483 274.502 0.006486400 0.486718 6
>55507 49600.500 -0.053164975 274.081 0.012851863 0.479047 6
>55507 49804.501 -0.072454909 273.200 0.013821606 0.545730 6
>
>With the clock behind 116ms at start, the frequency estimate is over
>3x too large.
>
>55507 50047.438 -0.082944166 0.000 0.029325191 0.000000 6
>55507 50051.440 -0.073052100 0.000 0.027432067 0.000000 6
>55507 50107.437 -0.012344934 0.000 0.026044324 0.000000 6
>55507 50175.438 -0.001425232 0.000 0.027895116 0.000000 6
>55507 50242.438 -0.000169852 0.000 0.031936190 0.000000 6
>55507 50246.438 -0.000149595 0.000 0.035742971 0.000000 6
>55507 50310.438 -0.000019610 0.000 0.039331450 0.000000 6
>55507 50376.438 -0.018851467 -57.292 0.043209685 0.000000 6
>55507 50442.437 -0.007240184 -57.292 0.040626900 0.000000 6
>55507 50447.437 -0.000713438 -57.292 0.038072978 0.000000 6
>55507 50451.438 0.005444657 -57.292 0.035680499 0.000000 6
>55507 50508.438 0.012774922 -57.292 0.033476519 0.000000 6
>55507 50518.439 0.014070419 -57.292 0.031317766 0.000000 6
>55507 50576.438 0.012945667 -57.292 0.029297786 0.000000 6
>55507 50587.438 0.009913733 -57.292 0.027426526 0.000000 6
>55507 50649.438 0.007395785 -57.292 0.025670607 0.000000 6
>55507 50978.438 0.008587284 -57.124 0.024016348 0.059537 6
>55507 51124.438 0.043736839 -56.743 0.025673396 0.145635 6
>55507 51520.438 0.089396351 -54.633 0.028936685 0.758356 6
>55507 51665.438 0.088605633 -53.867 0.027069234 0.759289 6
>55507 51933.438 0.112923072 -52.063 0.026740750 0.954559 6
>55507 52052.438 0.124493376 -51.180 0.025345971 0.945914 6
>55507 52118.438 0.127715005 -50.678 0.023736330 0.902475 6
>55507 52657.576 0.000000000 -50.678 0.000001907 0.844188 6
>55507 52664.576 0.016489190 -50.671 0.005829809 0.789670 6
>55507 52668.576 0.016691785 -50.667 0.005453758 0.738670 6
>55507 53067.576 0.026779525 -50.030 0.006224617 0.726726 6
>55507 53471.576 0.083394573 -48.022 0.020846117 0.982957 6
>55507 53832.576 0.110887775 -45.636 0.021788185 1.247820 6
>55507 54012.576 0.121168212 -44.336 0.020702544 1.254461 6
>55507 54077.577 0.125136632 -43.851 0.019416216 1.185893 6
>55507 54552.717 0.000000000 -43.851 0.000001907 1.109302 6
>
>Clock started 83ms ahead of reality, frequency estimate has the wrong sign.
>
>55507 55620.805 0.001022653 0.000 0.000361567 0.000000 6
>55507 55624.805 0.000900690 0.000 0.000344022 0.000000 6
>55507 55624.805 0.000900690 0.000 0.000331328 0.000000 6
>55507 55680.806 0.000152206 0.000 0.000635788 0.000000 6
>55507 55748.805 0.000017572 0.000 0.001913772 0.000000 6
>55507 55749.805 0.000017023 0.000 0.002925621 0.000000 6
>55507 55816.805 0.000002029 0.000 0.004627915 0.000000 6
>55507 55820.805 0.000001787 0.000 0.006756535 0.000000 6
>55507 55887.805 0.000000213 0.000 0.009488173 0.000000 6
>55507 55953.805 0.025053023 75.234 0.012286357 0.000000 6
>55507 56014.806 0.020799313 75.234 0.011590816 0.000000 6
>55507 56080.806 0.003262439 75.234 0.012489851 0.000000 6
>55507 56085.805 -0.002976502 75.234 0.011889591 0.000000 6
>55507 56284.806 -0.005790262 75.166 0.011166097 0.024282 6
>55507 56486.805 -0.004832251 75.107 0.010450418 0.030644 6
>55507 56619.806 -0.001653216 75.094 0.009839874 0.029037 6
>55507 57107.805 0.001371581 75.134 0.009266278 0.030606 6
>55507 57294.806 0.002566599 75.163 0.008678100 0.030363 6
>55507 57565.806 0.003550332 75.220 0.008125067 0.034897 6
>55507 57771.806 0.004306454 75.273 0.007605004 0.037617 6
>55507 58259.806 0.004533934 75.405 0.007114285 0.058414 6
>55507 58793.805 0.005079226 75.567 0.006657596 0.079074 6
>55507 58851.806 0.005470119 75.585 0.006229144 0.074268 6
>55507 59187.806 0.006022272 75.706 0.005830100 0.081514 6
>55507 59256.805 0.006003279 75.731 0.005453563 0.076748 6
>55507 59391.805 0.005970118 75.779 0.005101355 0.073773 6
>55507 59919.805 0.006141090 75.972 0.004772263 0.097114 6
>55507 60309.805 0.006432901 76.122 0.004465236 0.105107 6
>55507 60441.805 0.006557244 76.173 0.004177077 0.099996 6
>55507 60635.805 0.006560367 76.249 0.003907298 0.097307 6
>55507 60714.806 0.006276305 76.279 0.003656322 0.091620 6
>55507 61240.806 0.004699083 76.426 0.003465336 0.100290 6
>55507 61424.806 0.004688040 76.477 0.003241528 0.095558 6
>55507 61566.805 0.004881127 76.519 0.003032940 0.090572 6
>55507 62028.806 0.005194546 76.662 0.002839219 0.098669 6
>55507 62146.805 0.005274662 76.699 0.002655997 0.093223 6
>55507 62608.806 0.005172885 76.841 0.002484718 0.100701 6
>55507 62937.806 0.004712989 76.934 0.002329922 0.099704 6
>55507 63331.806 0.004662792 77.043 0.002179514 0.100980 6
>55507 63397.805 0.004648114 77.061 0.002038756 0.094680 6
>55507 63722.806 0.004832430 77.155 0.001908194 0.094547 6
>55507 64246.805 0.004666484 77.301 0.001785916 0.102357 6
>55507 64701.806 0.004691766 77.428 0.001670596 0.105788 6
>55507 64768.805 0.004609847 77.446 0.001562968 0.099170 6
>55507 65165.806 0.004017867 77.542 0.001476927 0.098667 6
>55507 65548.806 0.003799573 77.628 0.001383693 0.097256 6
>55507 65808.805 0.003839284 77.688 0.001294402 0.093375 6
>55507 65893.805 0.003827564 77.707 0.001210810 0.087613 6
>55507 66411.805 0.003819743 77.825 0.001132612 0.091952 6
>55507 66611.806 0.003747307 77.870 0.001059771 0.087451 6
>55507 66942.806 0.003664775 77.942 0.000991754 0.085704 6
>55507 67268.805 0.003395993 78.008 0.000932556 0.083495 6
>55507 67796.805 0.003322722 78.113 0.000872711 0.086411 6
>55507 68061.806 0.003407083 78.166 0.000816891 0.083039 6
>55507 68593.805 0.003187342 78.268 0.000768071 0.085501 6
>55507 68989.805 0.003164909 78.342 0.000718508 0.084227 6
>55507 69255.805 0.003198491 78.393 0.000672208 0.080801 6
>55507 69428.805 0.003139896 78.425 0.000629134 0.076445 6
>55507 69779.806 0.002965214 78.487 0.000591733 0.074796 6
>55507 69976.806 0.002849590 78.521 0.000555023 0.070958 6
>55507 70397.805 0.002597799 78.586 0.000526753 0.070263 6
>55507 70501.806 0.002577416 78.602 0.000492785 0.065967 6
>55507 70632.806 0.002619503 78.622 0.000461198 0.062129 6
>55507 70941.809 0.002597823 78.670 0.000431480 0.060528 6
>55507 71223.806 0.002607564 78.714 0.000403627 0.058701 6
>55507 71471.806 0.002375362 78.749 0.000386381 0.056296 6
>55507 71929.805 0.002268382 78.811 0.000363400 0.057030 6
>55507 71941.805 0.002310620 78.813 0.000340257 0.053349 6
>55507 72472.805 0.002392774 78.889 0.000319604 0.056633 6
>55507 72668.805 0.002407426 78.917 0.000299007 0.053901 6
>55507 72994.806 0.002265679 78.961 0.000284150 0.052767 6
>
>With the clock off by 1ms at start, the frequency estimate is about 5 PPM low.
>
>Happy hunting,
>Dave Hart
>
>On Sun, Nov 7, 2010 at 00:58 UTC, David L. Mills <mills at udel.edu> wrote:
>  
>
>>Dave,
>>
>>I think I have hunted down what is going on. It takes some serious
>>investigation. Turns out the modern adjtime(), at least in some systems, is
>>far from what I knew some years back. I have already described that era from
>>what I knew of SunOS, Ultrix, OSF/1 and Tru64, since I or my graduate
>>assistant  implemented the precision time kernel used in those production
>>systems. Today, at least Solaris and Linux have put up stuff that turns out
>>to be absolute poison when attempting things like measuring frequency.
>>
>>The original model I started with was (a) messier the initial offset and
>>tell adjtime() to slew the kernel to that offset; (b) after five minutes
>>assume the kernel has largely completed the slew, measure the current offset
>>anc compute the frequency. This is a little tricky, since the amount the
>>kernel has slewed the time must be added before computing the time
>>difference.
>>
>>Well, this didn't work, apparently because the kernel didn't do what it was
>>supposed to do. However, a hint is available in the form of the second phase
>>of the training interval where the residual offset is amortized while
>>holding the frequency constant. This involves periodically measuring the
>>offset and updating the adjtime() programmed offset. This works, as evident
>>my previous message. This could be due to a nonlinearity in the adjtime()
>>calculation of the slew rate, which is apparently higher the larger the
>>programmed offset. Apparently, the repeated calls to adjtime() eventually
>>lowers the offset and thus the slew rate to something reasonable. Whatever
>>the cause, the behavior when the frequency file is present is within
>>expectations.
>>
>>So, I did the same thing during the frequency measurement phase, with result
>>the following loopstats from a Solaris system with initial offset 122 ms, no
>>frequency file and the kernel enabled.
>>
>>55506 78196.297 0.122624404 0.000 0.043354274 0.000000 4
>>55506 78200.301 0.108000004 0.000 0.040745455 0.000000 4
>>55506 78208.300 0.083775590 0.000 0.040190338 0.000000 4
>>55506 78226.299 0.047307323 0.000 0.045698174 0.000000 4
>>55506 78244.298 0.026714020 0.000 0.054270636 0.000000 4
>>55506 78262.298 0.015085167 0.000 0.063186252 0.000000 4
>>55506 78280.298 0.008518459 0.000 0.071337915 0.000000 4
>>55506 78298.298 0.004810297 0.000 0.078439342 0.000000 4
>>55506 78316.298 0.002716332 0.000 0.084507033 0.000000 4
>>55506 78334.297 0.001533888 0.000 0.089652370 0.000000 4
>>55506 78352.298 0.000866173 0.000 0.094006017 0.000000 4
>>55506 78370.298 0.000489120 0.000 0.097751274 0.000000 4
>>55506 78388.297 0.000276202 0.000 0.100850407 0.000000 4
>>55506 78406.297 0.000155969 0.000 0.103480985 0.000000 4
>>55506 78424.297 0.000088074 0.000 0.105713875 0.000000 4
>>55506 78442.297 0.000049735 0.000 0.107604976 0.000000 4
>>55506 78460.297 0.000028085 0.000 0.109209608 0.000000 4
>>55506 78478.298 0.000015859 0.000 0.110570569 0.000000 4
>>55506 78496.298 0.003133702 10.416 0.111724541 0.000000 4
>>55506 78512.297 0.001806182 10.416 0.104509792 0.000000 4
>>55506 78528.297 0.000873748 10.416 0.097760515 0.000000 4
>>55506 78544.297 0.000362151 10.416 0.091446767 0.000000 4
>>55506 78656.297 0.000353000 12.931 0.085540618 0.889337 4
>>55506 78688.298 0.000354000 13.104 0.080015921 0.834140 4
>>55506 78720.297 0.000226000 13.214 0.074848054 0.781241 4
>>55506 78736.297 -0.000163000 13.175 0.070014079 0.730920 4
>>55506 78864.299 -0.000234000 12.718 0.065492179 0.702547 4
>>55506 78912.299 -0.000289000 12.506 0.061262326 0.661420 4
>>55506 78944.298 -0.000286000 12.366 0.057305659 0.620669 4
>>55506 78992.297 -0.000286000 12.157 0.053604536 0.585287 5
>>55506 79008.297 -0.000233000 12.143 0.050142455 0.547509 5
>>55506 79269.297 -0.000469000 11.676 0.046904046 0.538099 5
>>55506 79430.297 -0.000319000 11.480 0.043874749 0.508089 5
>>55506 79495.297 -0.000265000 11.414 0.041041075 0.475841 5
>>55506 79755.304 -0.000206000 11.210 0.038390415 0.450932 5
>>55506 79852.297 -0.000257000 11.115 0.035910950 0.423146 5
>>55506 79949.297 -0.000249000 11.023 0.033591618 0.397155 6
>>
>>It starts at second 78196 with offset 122 ms and frequency zero. At 300 s
>>later, second 78496, the frequency is set at 10.496, which happens to be
>>within 1 PPM of the nominal value. At this point the residual offset is
>>about 3.1 ms. At second 78544 the residual offset drops below 0.5 ms and the
>>frequency clamp is removed. However, there is about a 0.3 ms residual
>>offset, which at this low poll interval of 16 s and low time constant makes
>>the frequency loop rather sensitive, so the frequency jumps to 12.9 PPM.
>>While this slowly subsides to the e nominal value, note the residual offset
>>stays below 0.35 ms. Victory is declared
>>
>>I haven't tried this on other machines, but the sheer blunderbuss approach
>>here should tame even them. Your exploits to the contrary are invited. The
>>new code is in the backroom, but not yet a snapshot.
>>
>>Dave
>>
>>Dave Hart wrote:
>>
>>On Sat, Nov 6, 2010 at 03:34 UTC, David L. Mills <mills at udel.edu> wrote:
>>
>>
>>Now to the apparent initial frequency error. This is new, as tests in the
>>past have not confirmed that. I need to plant some debug code in
>>direct-freq().
>>
>>
>>I ran several more tests without a drift file on the same FreeBSD 6.4
>>machine, but now with the daemon loop.  The kernel frequency was reset
>>with ntptime -f 0.  This is using ntpd 4.2.7p78 with four LAN sources
>>each with less than 500ms delay on gigabit ethernet, maxpoll 6 and
>>iburst on each.  The machine's drift when settled stays over 79 and
>>under 81 PPM.
>>
>>55506 60099.298 0.112224703 0.000 0.039677424 0.000000 6
>>55506 60430.299 0.087985591 265.808 0.031875465 0.000000 6
>>55506 60497.299 0.082268047 265.808 0.029885212 0.000000 6
>>55506 60501.299 0.063703305 265.808 0.028715263 0.000000 6
>>55506 60566.299 0.044976216 265.808 0.027664662 0.000000 6
>>55506 60570.299 0.035161159 265.808 0.026109553 0.000000 6
>>55506 60632.299 0.016835865 265.808 0.025268008 0.000000 6
>>55506 60637.300 0.007505765 265.808 0.023865132 0.000000 6
>>55506 60699.299 -0.005871398 265.808 0.022819291 0.000000 6
>>55506 60703.299 -0.012182324 265.808 0.021461792 0.000000 6
>>
>>Above I slowed the clock by 110ms before starting ntpd, and its
>>frequency estimate is 3x too big.
>>
>>55506 61035.172 -0.109110664 0.000 0.038576445 0.000000 6
>>55506 61364.172 -0.039509331 -120.080 0.047442141 0.000000 6
>>55506 61432.172 -0.018407984 -120.080 0.045000783 0.000000 6
>>55506 61441.171 -0.000743150 -120.080 0.042555170 0.000000 6
>>55506 61570.172 -0.039411530 -120.383 0.042088955 0.107139 6
>>55506 61907.172 0.077963129 -118.817 0.057202679 0.562671 6
>>55506 62109.172 0.112914955 -117.457 0.054916590 0.712782 6
>>55506 62588.325 0.000000000 -117.457 0.000001907 0.666746 6
>>55506 62597.324 0.036879681 -117.437 0.013038936 0.623723 6
>>
>>This time opposite offset and the drift ends up with the wrong sign.
>>
>>55506 62673.088 0.046002361 0.000 0.016264291 0.000000 6
>>55506 63004.087 0.036022038 108.824 0.016594865 0.000000 6
>>55506 63072.088 0.024200794 108.824 0.016075870 0.000000 6
>>55506 63076.087 0.015639317 108.824 0.015339223 0.000000 6
>>55506 63139.087 0.007153841 108.824 0.014658809 0.000000 6
>>55506 63144.087 -0.001147804 108.824 0.014022670 0.000000 6
>>55506 63342.087 0.010581006 108.949 0.013756870 0.044150 6
>>55506 63546.087 -0.007289204 108.860 0.014335728 0.051841 6
>>55506 64089.087 -0.018442062 108.263 0.013977562 0.216530 6
>>55506 64156.087 -0.025361028 108.162 0.013301681 0.205686 6
>>55506 64224.087 -0.025423666 108.059 0.012442603 0.195821 6
>>
>>46ms slow, frequency is ~28 PPM too large.
>>
>>55506 64548.716 0.001700028 0.000 0.000601053 0.000000 6
>>55506 64879.717 0.023679569 71.539 0.010183162 0.000000 6
>>55506 64946.717 0.019872424 71.539 0.009620108 0.000000 6
>>55506 65013.717 0.002736900 71.539 0.010848108 0.000000 6
>>55506 65017.717 -0.008305963 71.539 0.010872643 0.000000 6
>>55506 65082.716 -0.004770959 71.539 0.010246931 0.000000 6
>>55506 65148.717 0.001608567 71.539 0.009846926 0.000000 6
>>55506 65219.717 0.012919477 71.594 0.010041603 0.019330 6
>>55506 65346.717 0.011396322 71.680 0.009408484 0.035457 6
>>55506 65486.716 0.003467074 71.709 0.009236544 0.034709 6
>>55506 65828.717 0.004913697 71.809 0.008655121 0.048044 6
>>55506 66236.717 0.006136544 71.959 0.008107660 0.069307 6
>>55506 66627.716 0.007779940 72.140 0.007606245 0.091173 6
>>55506 66776.716 0.009039619 72.220 0.007128916 0.089883 6
>>55506 67230.717 0.009392249 72.474 0.006669656 0.123060 6
>>55506 67373.716 0.009373844 72.554 0.006238895 0.118527 6
>>55506 67658.716 0.009579650 72.717 0.005836406 0.124912 6
>>55506 67908.717 0.009567647 72.860 0.005459459 0.127253 6
>>55506 67977.716 0.009286340 72.898 0.005107825 0.119797 6
>>55506 68513.717 0.009503342 73.201 0.004778549 0.155178 6
>>55506 68642.716 0.009570171 73.275 0.004469985 0.147469 6
>>55506 69168.716 0.009184942 73.563 0.004183506 0.171447 6
>>55506 69233.716 0.009189485 73.599 0.003913312 0.160868 6
>>55506 69365.716 0.009375908 73.672 0.003661161 0.152721 6
>>55506 69432.717 0.009193983 73.709 0.003425307 0.143446 6
>>55506 69959.717 0.008999743 73.992 0.003204817 0.167315 6
>>55506 70090.717 0.009024846 74.062 0.002997845 0.158480 6
>>55506 70155.716 0.008902531 74.097 0.002804561 0.148745 6
>>55506 70350.716 0.008570129 74.196 0.002626057 0.143526 6
>>55506 70672.716 0.008251968 74.355 0.002459026 0.145465 6
>>55506 71197.716 0.007350799 74.585 0.002322169 0.158521 6
>>55506 71456.716 0.007408970 74.699 0.002172288 0.153698 6
>>55506 71850.716 0.007506679 74.875 0.002032283 0.156700 6
>>55506 72376.716 0.007566595 75.113 0.001901145 0.168879 6
>>55506 72899.717 0.007325361 75.341 0.001780402 0.177408 6
>>55506 72965.716 0.007008212 75.368 0.001669184 0.166236 6
>>55506 73491.716 0.006596605 75.575 0.001568146 0.171833 6
>>55506 73689.716 0.006589897 75.653 0.001466868 0.163070 6
>>55506 74212.717 0.006427589 75.853 0.001373329 0.168186 6
>>55506 74407.717 0.006501221 75.929 0.001284895 0.159575 6
>>55506 74537.723 0.006513531 75.979 0.001201917 0.150332 6
>>55506 74672.717 0.006297412 76.030 0.001126884 0.141759 6
>>55506 74999.716 0.006044827 76.148 0.001057880 0.138992 6
>>55506 75524.716 0.005710565 76.327 0.000996588 0.144553 6
>>55506 75981.716 0.005532070 76.477 0.000934356 0.145334 6
>>55506 76313.716 0.005505819 76.586 0.000874059 0.141300 6
>>55506 76442.716 0.005524893 76.629 0.000817635 0.133025 6
>>55506 76768.716 0.005369956 76.733 0.000766787 0.129787 6
>>55506 77228.716 0.004834798 76.866 0.000741799 0.130137 6
>>55506 77685.716 0.004784225 76.996 0.000694120 0.130159 6
>>55506 78207.716 0.004621958 77.140 0.000651820 0.131942 6
>>55506 78273.716 0.004610433 77.158 0.000609735 0.123587 6
>>55506 78667.717 0.004535789 77.264 0.000570965 0.121585 6
>>55506 79191.716 0.004254460 77.397 0.000543272 0.123053 6
>>55506 79387.724 0.004210196 77.447 0.000508425 0.116412 6
>>55506 79451.716 0.004094866 77.462 0.000477333 0.109034 6
>>55506 79648.717 0.004053887 77.510 0.000446739 0.103371 6
>>55506 80173.716 0.003811266 77.629 0.000426599 0.105488 6
>>55506 80239.717 0.003807079 77.644 0.000399050 0.098817 6
>>55506 80761.716 0.003781913 77.762 0.000373383 0.101366 6
>>55506 80826.716 0.003742947 77.776 0.000349539 0.094957 6
>>55506 81286.717 0.003719909 77.878 0.000327066 0.095865 6
>>55506 81810.723 0.003575463 77.990 0.000310175 0.097981 6
>>55506 82008.717 0.003563863 78.032 0.000290171 0.092851 6
>>55506 82075.716 0.003460594 78.046 0.000273875 0.086991 6
>>55506 82139.716 0.003368641 78.059 0.000258241 0.081500 6
>>55506 82664.716 0.003331264 78.163 0.000241923 0.084677 6
>>55506 83058.716 0.003307356 78.240 0.000226456 0.083834 6
>>55506 83321.717 0.003079668 78.289 0.000226611 0.080255 6
>>55506 83452.716 0.002969860 78.312 0.000215501 0.075518 6
>>55506 83517.717 0.002958930 78.323 0.000201620 0.070757 6
>>55506 83646.716 0.002923137 78.346 0.000189022 0.066662 6
>>55506 84169.717 0.002828842 78.434 0.000179929 0.069717 6
>>55506 84233.716 0.002829801 78.445 0.000168310 0.065326 6
>>55506 84299.716 0.002810263 78.456 0.000157591 0.061232 6
>>55506 84823.716 0.002667552 78.539 0.000155809 0.064407 6
>>55506 85146.716 0.002627148 78.590 0.000146444 0.062845 6
>>55506 85601.716 0.002466953 78.657 0.000148233 0.063367 6
>>55506 86006.716 0.002419676 78.715 0.000139663 0.062769 6
>>55506 86122.717 0.002411172 78.732 0.000130677 0.059010 6
>>55506 86188.716 0.002383291 78.741 0.000122634 0.055298 6
>>
>>Under 2ms initial offset, the frequency estimate is ~8 PPM too small.
>>
>>Cheers,
>>Dave Hart
>>
>>    
>>
>>
>  
>




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