Re: [time-nuts] 5370 processor boards available
On 28/02/14 04:50, John Seamons wrote: On Feb 28, 2014, at 4:34 PM, Bob Camp li...@rtty.us wrote: Is there any performance data on how the card does with a 5370A and / or a 5370B compared to the original CPU on the exact same box? Put another way - does the counter get better or worse with the new card? I realize that an A will do some things with B firmware, that’s not the question I’m asking. I’m looking for A to A or B to B timing data. Yes. I made some measurements with the previous microcontroller-based board (48 MHz sam7x) versus the stock CPU card. I have not yet had a chance to repeat that exercise with the current board. Look at the 23-Jul-2011 entry on www.jks.com/5370/5370.html Very much dependent on what the measurement is, but a range of 5-72% faster. Early in the beta process there where an issue which caused incorrect readings and thus higher noise. It was resolved as I recall and noise level fell back to expected. Cheers, Magnus ___ 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] 5370 processor boards available
On 28/02/14 14:18, Poul-Henning Kamp wrote: In message 87caf1a2-d281-4331-b019-b01b06f11...@rtty.us, Bob Camp writes: To me the next layer here is to see if the basic accuracy of the device can be improved in software. I have a hard time seeing how that would happen. I think one of the best chances would be to improve the phase noise of the 200MHz signal. But don't miss the fact that being able to make a LOT more measurements in the same time also improves noise statistically. What one possibly could do is to see if there is any round-off issues that causes any noise. The interpolator does not have a number-magic friendly gearing for decimal or binary numbers, unless you play some magic with it. Rounding off causes the interpolator points to be un-evenly distributed and by that adding a little noise to the measurement. However, I would look at the 200 MHz systematics first. This was only to show what you could possibly do to improve precision in software. With a hotter CPU you can naturally do smarter auto-triggers and auto-tunes and things like that. Doing a CNT-90 like frequency estimator would indeed be possible and provide better frequency measures. Frequency drift estimator would maybe be a nice addition? Cheers, Magnus ___ 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] 5370 processor boards available
In message 5311b3eb.1000...@rubidium.dyndns.org, Magnus Danielson writes: What one possibly could do is to see if there is any round-off issues that causes any noise. The HP5370 firmware uses floating point to avoid exactly that issue, and all the math I've traced is good and competent. -- 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.
Re: [time-nuts] 5370 processor boards available
On 28/02/14 18:42, Tom Van Baak wrote: I think one of the best chances would be to improve the phase noise of the 200MHz signal. But don't miss the fact that being able to make a LOT more measurements in the same time also improves noise statistically. I agree with this. And it makes me wonder if someone on the list is now eyeing the SR 620 as the next classic instrument in need of a time nuts upgrade? It would be very cool if in the end both the hp5370 and the SR620 can be turned into true timestamping counters, a la the Pendulum CNT-9x and the Agilent 53230. Indeed. Just having ethernet and USB on them would help a lot. The key point is that you need to hide the dead-time between the stop trigger and the arm trigger. You also need continuous time to be assuered, which typically means a runnning time counter. None of them is made to be a zero dead-time counter, where as HP-5371/5372/5373 and CNT-9x is. I think one has to think a little about how the counter HW is being extended to achieve the true ZDT properties. The typical way for getting these counters hide their dead-time have been a higher rate trigger signal than arm signal (typcially x2). The other way is to use a pair of counters and having them being armed on every other measure. Cheers, Magnus ___ 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] 5370 processor boards available
On 01/03/14 11:31, Poul-Henning Kamp wrote: In message 5311b3eb.1000...@rubidium.dyndns.org, Magnus Danielson writes: What one possibly could do is to see if there is any round-off issues that causes any noise. The HP5370 firmware uses floating point to avoid exactly that issue, and all the math I've traced is good and competent. OK. Good. I've seen it with others. In fact, I learned about the issue when seeing data from Pendelum as they where a little confused about it. Cheers, Magnus ___ 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] Why using HP5370 ext-ref is (maybe) a bad idea
On 01/03/14 01:47, Bob Camp wrote: Hi There is a fairly involved alignment process for the multiplier chain. My *guess* is that small tweaks to the alignment could impact these timing spikes. Sub harmonics tend to produce multiple zero crossings that show up as periodic jitter in the output. The offset input peaks may be a better thing to look at as you tweak the multiplier than the “official” adjustment procedure. It was exactly what I was hinting about, it may be a better procedure as it addresses the actual precision rather than indirect phase noise measures. Just doing phase-noise measures rather than spectrum analysis helped to illustrate the problem. Cheers, Magnus ___ 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] ADEV from phase or frequency measurement
Hello dear fellow time-nuts, I stumbled over a question that may sound stupid to you: Is the usual ADEV plot the result of a phase or a frequency measurement? I get totally different results when comparing a phase and a frequency measurement of the same source. Or am I doing something totally wrong? Thanks a lot Volker ___ 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] ADEV from phase or frequency measurement
Hi Volker, Either phase or frequency raw data can be used to generate an ADEV plot, but you have to use different methods depending on the data type. See the two formulas for Allan Variance in: http://www.wriley.com/paper2ht.htm Usually we use the x form of the formula, where x is an array of phase samples. But if you have frequency samples then use the y form instead, where y is an array of frequency samples. Note you can also convert phase data to frequency data (by differentiating) and use the y form. Or convert frequency data to phase data (by integrating) and use the x form. /tvb - Original Message - From: Volker Esper ail...@t-online.de To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Saturday, March 01, 2014 3:15 AM Subject: [time-nuts] ADEV from phase or frequency measurement Hello dear fellow time-nuts, I stumbled over a question that may sound stupid to you: Is the usual ADEV plot the result of a phase or a frequency measurement? I get totally different results when comparing a phase and a frequency measurement of the same source. Or am I doing something totally wrong? Thanks a lot Volker ___ 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] ADEV from phase or frequency measurement
Thank you, Tom, so far. Yes, I know that I have to use different formulas, but - of course - I didn't calculate the ADEV curves myself, I let some software do the job, namely Ulrich's Plotter and TimeLab as well. Plotter has a menu item, where you have to check if you deal with phase or frequency data, so I assumed the software would do right. I am confused. The ADEVs of the phase data are about 10 times better and have a different shape... Volker Am 01.03.2014 12:37, schrieb Tom Van Baak: Hi Volker, Either phase or frequency raw data can be used to generate an ADEV plot, but you have to use different methods depending on the data type. See the two formulas for Allan Variance in: http://www.wriley.com/paper2ht.htm Usually we use the x form of the formula, where x is an array of phase samples. But if you have frequency samples then use the y form instead, where y is an array of frequency samples. Note you can also convert phase data to frequency data (by differentiating) and use the y form. Or convert frequency data to phase data (by integrating) and use the x form. /tvb - Original Message - From: Volker Esper ail...@t-online.de To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Saturday, March 01, 2014 3:15 AM Subject: [time-nuts] ADEV from phase or frequency measurement Hello dear fellow time-nuts, I stumbled over a question that may sound stupid to you: Is the usual ADEV plot the result of a phase or a frequency measurement? I get totally different results when comparing a phase and a frequency measurement of the same source. Or am I doing something totally wrong? Thanks a lot Volker ___ 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] ADEV from phase or frequency measurement
Here is python code for the most common deviations https://github.com/aewallin/allantools/blob/master/allantools/allantools.py each statistic (ADEV, MDEV, TDEV, and so on) has two functions. one takes fractional frequency data, the other phase data. frequency2phase() and phase2freqeuncy() show how the conversions are done. Your patches are welcome! Anders On Sat, Mar 1, 2014 at 1:37 PM, Tom Van Baak t...@leapsecond.com wrote: Hi Volker, Either phase or frequency raw data can be used to generate an ADEV plot, but you have to use different methods depending on the data type. See the two formulas for Allan Variance in: http://www.wriley.com/paper2ht.htm Usually we use the x form of the formula, where x is an array of phase samples. But if you have frequency samples then use the y form instead, where y is an array of frequency samples. Note you can also convert phase data to frequency data (by differentiating) and use the y form. Or convert frequency data to phase data (by integrating) and use the x form. /tvb - Original Message - From: Volker Esper ail...@t-online.de To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Saturday, March 01, 2014 3:15 AM Subject: [time-nuts] ADEV from phase or frequency measurement Hello dear fellow time-nuts, I stumbled over a question that may sound stupid to you: Is the usual ADEV plot the result of a phase or a frequency measurement? I get totally different results when comparing a phase and a frequency measurement of the same source. Or am I doing something totally wrong? Thanks a lot Volker ___ 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] ADEV from phase or frequency measurement
Volker, On 01/03/14 12:15, Volker Esper wrote: Hello dear fellow time-nuts, I stumbled over a question that may sound stupid to you: Is the usual ADEV plot the result of a phase or a frequency measurement? I get totally different results when comparing a phase and a frequency measurement of the same source. Or am I doing something totally wrong? The core of the ADEV is the square of the second degree derivate of phase, where the phase measures are tau seconds away from each other. You can use frequency measures, but it is likely that the start-point of the next measure is not the end point of the previous frequency measure. Then you have dead-time. Dead-time causes a bias in the ADEV measure and you need to use the dead-time bias function to compensate for this effect. This was explained by Dave Allan in his Feb 1966 article, as the 2-point dead-time free variance was the unification of a large range of different measures, and he supplied the bias functions to unify them. Now that there was one variance to forge them all, they kept referring to it as Allan's variance and well, it's now history. Another aspect is that your counter may do some smart filtering on the measures it makes. This reduces the bandwidth of the counter as the averaging removes noise. This also causes low-tau values that has white-phase noise to be lower than expected. This improvement is however not helping you to get better ADEV, it just fools you, as the ADEV of white phase noise will depend on the measurement bandwidth, known for a long time but ignored my many measurement setups. I've tried to cover these topics on the Allan Variance Wikipedia article. I would avoid using frequency measures from counters if phase measures can be made, as you can avoid both these issues rather than requiring to measure their effect and compensate for it. It is tricky to maintain valid numbers that way. There are cases where ADEV is better calculated from frequency measures, so it is a valid tool, but care always needs to be taken to make sure the numbers remains scaled properly. Cheers, Magnus ___ 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] Thermal Compensation: Digital vs Analog
On 26/02/14 17:09, Bob Stewart wrote: I've been experimenting with digital thermal compensation on my GPSDO. The results have been favorable for a 14 bit dithered PWM-based DAC, but leaves a bit to be desired in the big picture. And it takes up a lot of program bytes on my PIC.. What's the general consensus on this? Should thermal compensation be completely analog? Considering that time-constants can be fairly long, there is a benefit in having at least that part of the integrator in digital domain. There are benefits of both approaches. Resolution of input and output can be a problem for the digital solution. Cheers, Magnus ___ 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] ADEV from phase or frequency measurement
On 01/03/14 13:25, Volker Esper wrote: Thank you, Tom, so far. Yes, I know that I have to use different formulas, but - of course - I didn't calculate the ADEV curves myself, I let some software do the job, namely Ulrich's Plotter and TimeLab as well. Plotter has a menu item, where you have to check if you deal with phase or frequency data, so I assumed the software would do right. I am confused. The ADEVs of the phase data are about 10 times better and have a different shape... Can you supply the TimeLab plots or even measurement files? What was your counter and setup? Cheers, Magnus ___ 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] HP 5335A counters
Greetings to all time nuts. I have several HP 5335A counters and am really impressed by them. One has an error code (4.6) displayed on startup and I have not got that sorted out yet. FWIW: Last Saturday I noticed that the Ebay seller testgearnation had 3 HP 5335A counters for sale (CONUS only) for what I thought was a very reasonable fixed price. I purchased one of them and it arrived on Wedensday. Looks great and seems to operate just fine. I have not used it extensivilly but I am pleased. 73 Happy timekeeping, Gordon WA4FJC ___ 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] FE-5680A sweep range setting
On 24/02/14 19:14, Paul Berger wrote: A couple further observations, to make life easier when adjusting C245 you can unplug the top card and move it aside, the CVXO will lock without it, but you will not have the 10MHz to monitor, but you can monitor the CVXO output instead. On the 6 pin connector you will see a 1 near the outer long edge of the second card, the CVXO output appears on pin 5 of this connector and on mine, it locks at 50.25505808 MHz according to my 5335A. I also noted that when the 5680A is well warmed up it sweeps through a much smaller range. In that case it would be good if the mid voltage would be established, so that once lock have been achieved, further trimming can be done until the VCXO steering is in the middle of the range. That would make sure there is plenty of margin to either end, rather than sitting on the edge and just barely lock. Cheers, Magnus ___ 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] FTS 2000A
Hi Bert, On 14/02/14 17:55, ewkeh...@aol.com wrote: Attached the innards of a FTS 2000A. The unit obviously does not have a thermal fuse. Solder had melted and the XTAL was loose inside. Do not know what happened since I got it that way Bert Kehren Thanks for sharing! I rarely say it, but now it applies: YUCK! Cheers, Magnus ___ 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] FE-5680A sweep range setting
Hi I am not at all sure that a mid setting on the VCXO is really the right thing to do. I’ve seen quite a few Rb’s from a number of manufacturers. They all seem to set up the sweep process so it sweeps fairly far low but not very far high. There are multiple quantum state transitions possible with a Rb. They may be trying to get the good one and avoid a near by bad one. Bob On Mar 1, 2014, at 10:35 AM, Magnus Danielson mag...@rubidium.dyndns.org wrote: On 24/02/14 19:14, Paul Berger wrote: A couple further observations, to make life easier when adjusting C245 you can unplug the top card and move it aside, the CVXO will lock without it, but you will not have the 10MHz to monitor, but you can monitor the CVXO output instead. On the 6 pin connector you will see a 1 near the outer long edge of the second card, the CVXO output appears on pin 5 of this connector and on mine, it locks at 50.25505808 MHz according to my 5335A. I also noted that when the 5680A is well warmed up it sweeps through a much smaller range. In that case it would be good if the mid voltage would be established, so that once lock have been achieved, further trimming can be done until the VCXO steering is in the middle of the range. That would make sure there is plenty of margin to either end, rather than sitting on the edge and just barely lock. Cheers, Magnus ___ 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] ADEV from phase or frequency measurement
This is because usually a counter that has the time interval feature behaves better in time interval mode. As already pointed out here, use always the time interval mode to take samples for the Allan deviation. In frequency mode the counter uses average or various tricks to smooth readings, so better to switch to time interval mode in order to take clean samples for the post processing. On Sat, Mar 1, 2014 at 1:25 PM, Volker Esper ail...@t-online.de wrote: Thank you, Tom, so far. Yes, I know that I have to use different formulas, but - of course - I didn't calculate the ADEV curves myself, I let some software do the job, namely Ulrich's Plotter and TimeLab as well. Plotter has a menu item, where you have to check if you deal with phase or frequency data, so I assumed the software would do right. I am confused. The ADEVs of the phase data are about 10 times better and have a different shape... Volker Am 01.03.2014 12:37, schrieb Tom Van Baak: Hi Volker, Either phase or frequency raw data can be used to generate an ADEV plot, but you have to use different methods depending on the data type. See the two formulas for Allan Variance in: http://www.wriley.com/paper2ht.htm Usually we use the x form of the formula, where x is an array of phase samples. But if you have frequency samples then use the y form instead, where y is an array of frequency samples. Note you can also convert phase data to frequency data (by differentiating) and use the y form. Or convert frequency data to phase data (by integrating) and use the x form. /tvb - Original Message - From: Volker Esper ail...@t-online.de To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Saturday, March 01, 2014 3:15 AM Subject: [time-nuts] ADEV from phase or frequency measurement Hello dear fellow time-nuts, I stumbled over a question that may sound stupid to you: Is the usual ADEV plot the result of a phase or a frequency measurement? I get totally different results when comparing a phase and a frequency measurement of the same source. Or am I doing something totally wrong? Thanks a lot Volker ___ 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] Why using HP5370 ext-ref is (maybe) a bad idea
Instead of using the external reference input, any thoughts on actually disciplining the internal OCXO to bypass the problem? -- Brian Lloyd, WB6RQN/J79BPL 706 Flightline Drive Spring Branch, TX 78070 br...@lloyd.com +1.916.877.5067 ___ 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] LORAN C 89700 on the air starting Monday
Wildwood will be on air from approximately 1400 on 02 March until 1400 on 04 March Regards Paul WB8TSL ___ 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] Why using HP5370 ext-ref is (maybe) a bad idea
On Mar 2, 2014, at 6:20 AM, Brian Lloyd br...@lloyd.com wrote: Instead of using the external reference input, any thoughts on actually disciplining the internal OCXO to bypass the problem? I almost put a GPS front-end chip and small FPGA on the 5370 board. You can imagine where that idea was going. I mean, you've got that whole BeagleBone just sitting there with some spare cycles now that I use the PRU. But it would have doubled the BOM cost. Probably more depending on the choice of DAC solution. ___ 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] Software for Brilliant Instruments B1220?
Does anyone have access to a copy of the software for the Brilliant Instruments B1220? I just purchased one off of eBay and, of course, they don't have it. Thanks, Richard Parrish calc...@swbell.net ___ 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] LORAN C 89700 on the air starting Monday
Paul, Do you know if this is a prelude to continuous service? -John === Wildwood will be on air from approximately 1400 on 02 March until 1400 on 04 March Regards Paul WB8TSL ___ 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] Why using HP5370 ext-ref is (maybe) a bad idea
Idea. On the next go around for the board put the copper down and holes for a couple small daughter cards and any support logic needed to interface with the BBB. The the only additional cost would be limited to the daughter board I/O since my guess it would be SMT hence a bit hard to leave it unpopulated. -pete On Sat, Mar 1, 2014 at 9:39 AM, John Seamons j...@jks.com wrote: On Mar 2, 2014, at 6:20 AM, Brian Lloyd br...@lloyd.com wrote: Instead of using the external reference input, any thoughts on actually disciplining the internal OCXO to bypass the problem? I almost put a GPS front-end chip and small FPGA on the 5370 board. You can imagine where that idea was going. I mean, you've got that whole BeagleBone just sitting there with some spare cycles now that I use the PRU. But it would have doubled the BOM cost. Probably more depending on the choice of DAC solution. ___ 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] Software for Brilliant Instruments B1220?
Contact Brilliant Instruments (4088660426). I was at the office yesterday loading the new version that they just released on my TIA's and can tell you The new software works beautifully. They are amazing to work with, being the little guy on the block making amazing devices and all. Ask for Shalom or Daniel and I am sure they can get you set up and counting. Rob Sent from my Verizon Wireless BlackBerry -Original Message- From: Richard Parrish calc...@swbell.net Sender: time-nuts-boun...@febo.com Date: Sat, 1 Mar 2014 11:55:09 To: time-nuts@febo.com Reply-To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: [time-nuts] Software for Brilliant Instruments B1220? Does anyone have access to a copy of the software for the Brilliant Instruments B1220? I just purchased one off of eBay and, of course, they don't have it. Thanks, Richard Parrish calc...@swbell.net ___ 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] LORAN C 89700 on the air starting Monday
Hi Paul, Is that EST or GMT time? 73, Bill, WA2DVU Cape May, NJ ( 10 miles from Wildwood!) -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of paul swed Sent: Saturday, March 01, 2014 12:18 PM To: Time-nuts Subject: [time-nuts] LORAN C 89700 on the air starting Monday Wildwood will be on air from approximately 1400 on 02 March until 1400 on 04 March Regards Paul WB8TSL ___ 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] New England Ham - Electronic Fleamarket Dates * March * update]
New England Area Ham - Electronic Flea Market *** DATES *** 2014 P 1 of 2 All events are Ham Radio/ Electronic related except ~_~ *** 2014Contact Source ~~ 1 Mar Chicopee MA MtTomARA @MooseLodge @8:30 S@6:30 Mary KB1ME 413 222 1990 F+ 2 Mar Hicksville NY LIMARC @LevitHall $6@9 $20/T Richie K2KNB 516 694 4937 W 15 Mar Dayville CT ECARA @StJosephCh $3@8A $10/TPeter K1LNX 401 603 1485 F 15 Mar N Conway NH WMARC @CommCtr $3@9 $10/TGreg KB1EZJ 603 759 6671 F 16 Mar Southington CT SARA $5@8A @HS $20/T@6:15 eve Norm W3IZ 860 584 1403 F 23 Mar Henniker NH CVRC @CommSch Don N1ZIH 603 651 8000 W+ 28,29 Mar Lewiston ME AARC ME Conv @Ramada @8Ivan N1OXA 207 784 0350 29 Mar Montreal PQ CRALL @GeoVanierHSNormand VE2NHK 514 708 8033 R+ 6 Apr Framingham MA FARA @Keefe Tech $5@9 $25/T@7:30 Bev N1LOO 508 626 2012 + 12,13 Apr Wakefield MA Photographica @AmericalCtr ~photo~ John 781 592 2553 F 12 Apr Windsor CT VR+C Mus 115 Pierson LN @8AM Outdoor John 860 673 0518 12 Apr Montreal PQ MARC @StIgnatiusCh $5@9 $8/T@8:15 James 514 990 1965 W 13 Ap Manchester CT NEWS V/UHFConf @Baymount@8 I84x63 MarkK1MAP 413 566 8118 W+ 19 Apr S.Portland ME PAWA @AmLegion $6@8 $10/T@6:30 Bryce K1GAX 207 415 0498 W+ 20 Apr Cambridge MA FLEA at MITMitch 617 253 3776 F Third Sunday April thru October 26 Ap Gales Ferry CT RANSON Auction @FireHs $2@9Gary WT1SND 860 884 4218 W+ 26 Apr Brookline NH NEARC Antique $5@8:30 $10@7:30Bruce 603 772 7516 F+ 27 Ap Middletown NY OCARA @CommCtr $7@9 $12Sell Neil AC2O 914 490 2001 F 2,3 May Deerfield NH NEARfest XV @FG Mike K1TWF 978 250 1235 R 10 May E Greenbush NY EGARA @FireCo $6@8 $6/T@6 Tom KC2FCP 518 272 1494 W *** LAST UPDATE 2-27-14 de W1GSL http://swapfest.us P 1 List is normally updated twice a month - look for the latest version *** Additions/ Corrections via e-Mail w1...@mit.edu - SUBSCRIBE US Mail W1GSL POB 397082 MIT Br Cambridge MA 02139 (c)2014 W1GSL unlimited reproduction permitted in entirety FF New England Area Ham - Electronic Flea Market *** DATES *** 2014 P2 of 2 *** 2014Contact Source ~~ 18 May Cambridge MA FLEA at MITMitch 617 253 3776 F Third Sunday April thru October 31 May Goshen CT SBARC @FG Rt63 Marc K1CTT 860 672 2659 A+ 1 June Bethpage NY LIMARC @Briarcliffe Dave AK1NS 516 312 8745 A+ 7 June Hermon ME PSARA @8 @HS TG@6:30 Jerry K1GUP 207 848 3400 W 7 June Windsor CT VR+C Mus 115 Pierson LN @8AM Outdoor John 860 673 0518 8 June Queens NY HoSARC Stephen WB2KDG 718 898 5599 A+ 15 June Cambridge MA FLEA at MITMitch 617 253 3776 F 21 June Newington CT NARL @StMarySch Quentin KB1EWM 860 383 8203 A+ 18,19 July Hartford CT ARRL Nat Conv 100th Anv. 860 594 0200 W 20 July Cambridge MA FLEA at MITMitch 617 253 3776 F 9 Aug Milo ME PARC @AmLegion George WA1JMM 207 441 6112 A+ 17 August Cambridge MAFLEA at MITMitch 617 253 3776 F 24 Aug Adams MA NoBARC @BoweFld $5@9 $10S@8 Eric KA1SUN 413 743 9975 F+ 6 Sept Windsor CT VR+C Mus 115 Pierson LN @8AM Outdoor John 860 673 0518 20 Sept Forestdale RI RIAFMRS @VFW $5/Sp@8 Pete AA1PL 401 639 4484 T 21 Sept Cambridge MA FLEA at MITMitch 617 253 3776 F 27 Sept Brookline NH NEARC Antique $5@8:30 $10@7:30 Bruce 603 772 7516 F+ 5 Oct Queens NY HoSARC Stephen WB2KDG 718 898 5599 W+ 10,11 Oct Deerfield NH NEARfest XVI @FG Mike K1TWF 978 250 1235 12 Oct Meriden CT Nutmeg @Sheraton was Wallingford John N1GNV 203 440 4973 18,19 Oct Wakefield MA Photographica @AmericalCtr ~photo~ John 781 592 2553 19 Oct Cambridge MA FLEA at MITMitch 617 253 3776 F *** LAST UPDATE 2-27-14 de W1GSL http://swapfest.us P 2 of 2 List is normally updated twice a month - look for the latest version SourceF+= Flyer T= tentative early info + = new info this month
Re: [time-nuts] FE-5680A sweep range setting
Hi Bob, On 01/03/14 16:55, Bob Camp wrote: Hi I am not at all sure that a mid setting on the VCXO is really the right thing to do. It's not really the right thing to do. You should trim it to one end so that further continuous drift makes trimming time longer than putting it at the mid. I’ve seen quite a few Rb’s from a number of manufacturers. They all seem to set up the sweep process so it sweeps fairly far low but not very far high. There are multiple quantum state transitions possible with a Rb. They may be trying to get the good one and avoid a near by bad one. Since the nearby bad ones is evenly distributed around the central good one, your way of reasoning doesn't really work. Cheers, Magnus ___ 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] Why using HP5370 ext-ref is (maybe) a bad idea
On 01/03/14 18:20, Brian Lloyd wrote: Instead of using the external reference input, any thoughts on actually disciplining the internal OCXO to bypass the problem? Considering that it's a HP10811A, it shouln't be too hard. In general, doing a new A8 board might be an option. Cheers, Magnus ___ 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] FE-5680A sweep range setting
Hi I seem to recall that many of the bad transitions get ruled out for this or that reason. The number of “threats” isn’t as big as you might think. There is basically one close in transition and everything else is quite a bit further out. Bob On Mar 1, 2014, at 1:48 PM, Magnus Danielson mag...@rubidium.dyndns.org wrote: Hi Bob, On 01/03/14 16:55, Bob Camp wrote: Hi I am not at all sure that a mid setting on the VCXO is really the right thing to do. It's not really the right thing to do. You should trim it to one end so that further continuous drift makes trimming time longer than putting it at the mid. I’ve seen quite a few Rb’s from a number of manufacturers. They all seem to set up the sweep process so it sweeps fairly far low but not very far high. There are multiple quantum state transitions possible with a Rb. They may be trying to get the good one and avoid a near by bad one. Since the nearby bad ones is evenly distributed around the central good one, your way of reasoning doesn't really work. Cheers, Magnus ___ 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] Why using HP5370 ext-ref is (maybe) a bad idea
On Mar 2, 2014, at 7:05 AM, Pete Lancashire p...@petelancashire.com wrote:
Idea. On the next go around for the board put the copper down and holes for
a couple small daughter cards and any support logic needed to interface
with the BBB.
The the only additional cost would be limited to the daughter board I/O
since my guess it would be SMT hence a bit hard to leave it unpopulated.
Good idea. Also the Beagle spec allows for multiple, stacked interface boards
('capes' they call them). So for a backwards compatible solution an
experimental GPSDO + backup power cape could be interposed between the Beagle
and 5370 board. I say experimental because I have no idea if any of the SDGPS
projects out there would be ultimately suitable for a DO.
This brings up a question I have about how the PPS edge is actually derived by
a GPS receiver. Does it originally come from the NAV data stream and then get
corrected by the (fixed-mode) positioning solution to account for
transmission/system delays? I know about the issue of alignment with the VCTCXO
clock, but I'm talking about upstream of that.
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Re: [time-nuts] Why using HP5370 ext-ref is (maybe) a bad idea
Hi
They run an NCO (drop / add pulses) to generate the PPS off of the TCXO. The
amount of adjustment is a function of the solution they derive from the GPS
messages. In some cases they do a solution, and correct the *next* edge to that
solution. In other chip sets the solution and the edge come out at the same
time.
Bob
On Mar 1, 2014, at 2:02 PM, John Seamons j...@jks.com wrote:
On Mar 2, 2014, at 7:05 AM, Pete Lancashire p...@petelancashire.com wrote:
Idea. On the next go around for the board put the copper down and holes for
a couple small daughter cards and any support logic needed to interface
with the BBB.
The the only additional cost would be limited to the daughter board I/O
since my guess it would be SMT hence a bit hard to leave it unpopulated.
Good idea. Also the Beagle spec allows for multiple, stacked interface boards
('capes' they call them). So for a backwards compatible solution an
experimental GPSDO + backup power cape could be interposed between the Beagle
and 5370 board. I say experimental because I have no idea if any of the SDGPS
projects out there would be ultimately suitable for a DO.
This brings up a question I have about how the PPS edge is actually derived
by a GPS receiver. Does it originally come from the NAV data stream and then
get corrected by the (fixed-mode) positioning solution to account for
transmission/system delays? I know about the issue of alignment with the
VCTCXO clock, but I'm talking about upstream of that.
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Re: [time-nuts] LORAN C 89700 on the air starting Monday
Doubt its continuous and no idea utc or local but may guess its local. If UTC would be 0900 and thats about work time. But you have all of the info I have. Regards Paul On Sat, Mar 1, 2014 at 1:00 PM, Bill Riches bill.ric...@verizon.net wrote: Hi Paul, Is that EST or GMT time? 73, Bill, WA2DVU Cape May, NJ ( 10 miles from Wildwood!) -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of paul swed Sent: Saturday, March 01, 2014 12:18 PM To: Time-nuts Subject: [time-nuts] LORAN C 89700 on the air starting Monday Wildwood will be on air from approximately 1400 on 02 March until 1400 on 04 March Regards Paul WB8TSL ___ 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] Why using HP5370 ext-ref is (maybe) a bad idea...
I don't know if this has any value here, but several years back I had a problem with my IFR-1500 Service Monitor. When I would externally lock it to my 10 MHz DATUM I would see jitter in the signals being measured with the IFR. It turned out to be leakage in the IFR's solid state switch that was allowing some of the internal oscillator to be mixed in with the external reference. I added a 2NA transistor to short out the internal oscillator's output to the original switch. The 2NA's base is fed from the Ext REF LED voltage. This solved the problem. Burt, K6OQK From: Magnus Danielson mag...@rubidium.dyndns.org Subject: Re: [time-nuts] Why using HP5370 ext-ref is (maybe) a bad idea On 01/03/14 18:20, Brian Lloyd wrote: Instead of using the external reference input, any thoughts on actually disciplining the internal OCXO to bypass the problem? Considering that it's a HP10811A, it shouln't be too hard. In general, doing a new A8 board might be an option. Cheers, Magnus Burt I. Weiner Associates Broadcast Technical Services Glendale, California U.S.A. b...@att.net www.biwa.cc K6OQK ___ 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] LORAN C 89700 on the air starting Monday
Paul, Where are you finding this information? -eric On Sat, Mar 1, 2014 at 11:08 AM, paul swed paulsw...@gmail.com wrote: Doubt its continuous and no idea utc or local but may guess its local. If UTC would be 0900 and thats about work time. But you have all of the info I have. Regards Paul On Sat, Mar 1, 2014 at 1:00 PM, Bill Riches bill.ric...@verizon.net wrote: Hi Paul, Is that EST or GMT time? 73, Bill, WA2DVU Cape May, NJ ( 10 miles from Wildwood!) -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of paul swed Sent: Saturday, March 01, 2014 12:18 PM To: Time-nuts Subject: [time-nuts] LORAN C 89700 on the air starting Monday Wildwood will be on air from approximately 1400 on 02 March until 1400 on 04 March Regards Paul WB8TSL ___ 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. -- --Eric _ Eric Garner ___ 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] LORAN C 89700 on the air starting Monday
Contact Steve and he will add you to the email. It took a month or so. stephen.bartl...@ursanav.com Regards Paul. On Sat, Mar 1, 2014 at 2:26 PM, Eric Garner garn...@gmail.com wrote: Paul, Where are you finding this information? -eric On Sat, Mar 1, 2014 at 11:08 AM, paul swed paulsw...@gmail.com wrote: Doubt its continuous and no idea utc or local but may guess its local. If UTC would be 0900 and thats about work time. But you have all of the info I have. Regards Paul On Sat, Mar 1, 2014 at 1:00 PM, Bill Riches bill.ric...@verizon.net wrote: Hi Paul, Is that EST or GMT time? 73, Bill, WA2DVU Cape May, NJ ( 10 miles from Wildwood!) -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of paul swed Sent: Saturday, March 01, 2014 12:18 PM To: Time-nuts Subject: [time-nuts] LORAN C 89700 on the air starting Monday Wildwood will be on air from approximately 1400 on 02 March until 1400 on 04 March Regards Paul WB8TSL ___ 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. -- --Eric _ Eric Garner ___ 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] Software for Brilliant Instruments B1220?
I need some advice on the HP8505A it will not vary the rf frequency output it randomly show the counter readingb ut the frequency will not change I tested with a counter. Thank You Sal C. Cornacchia Electronic RF Engineer Ret. On Saturday, March 1, 2014 12:58:04 PM, Richard Parrish calc...@swbell.net wrote: Does anyone have access to a copy of the software for the Brilliant Instruments B1220? I just purchased one off of eBay and, of course, they don't have it. Thanks, Richard Parrish calc...@swbell.net ___ 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] Arduino GPSDO with 1ns res TIC
Hej Lars, Impressive build in all it's simplicity. Your filtering equations look strange. Rather than having a PI loop it looks like both the P and I branch integrates. I'm also unclear about the loop gain changes by the pre-filter averager. Will have to look more at your code. Cheers, Magnus On 12/02/14 23:10, Lars Walenius wrote: I have just changed all my Swedish comments in my source code and attached it. I also copied the text to a Word-file so everybody can see it without the Arduino Environment. The Control loop (“PI-loop”) is more or less just two lines that you find approximately in the middle of the file (page 13 in Word-file). Check the two lines with comment: Corr for time respectively Corr for frequency. As you say, Chris, it would be a good idea to use a smaller Arduino board or I have also thought of the 28pin DIP with Arduino bootloader. I have a couple of them from Digikey. Together with a FT232RL board (from China) it also could work well. With that it should also be possible to add optocouplers for isolation to the computer (have not tested it yet). I see a lot of possibilities to improve the design. As you say adding an external DAC (monotonic 16-20bits) and/or ADC, LCD. Also more EEPROM for logging, soft serial lines to read e.g. M12 sawtooth information to correct the TIC Reading are possibilities. Another thing that is important if you want a really good GPSDO is buffering and a good metal case for screening. I don´t have it so I get disturbances on other electronics like my DIY 10volts references that on a couple of them moves several ppm´s due to 10MHz leakage. The third attachment is an ADEV+MDEV plot, made with the excellent Plotter program made by Ulrich Bangert, I just did from eight hours run between a LPRO Rb GPSDO in holdmode ( free running ) and another OCXO GPSDO with time constant set to 1000secs. The 1PPS was from a M12 timing receiver. The OCXO has 4 HC390 dividers and was set to output 1Hz into the start channel of a HP5370B. The LPRO has 2 HC390 dividers and was set to give 1kHz into the stop channel of the HP5370B. As you can see the ADEV seems to be about 2E-12 at Tau=1000s. An interesting thing I haven´t observed before is the minimas at 10,20,30 etc Tau. A question I have is if it could be due to the 0.1Hz output from the HC390 on the OCXO leaking into the 1Hz output? Is that reasonable or is it another explanation for this? Lars Från: Chris Albertson Skickat: onsdag den 12 februari 2014 02:32 Till: time-nuts@febo.com Lars, Thanks for posting this. I think your design will be popular especially with availability of the nano size Arduinos that sell for $4 from China. Your design could be built on a 3 perf board for about $10 with change left over. (not counting the OCXO and GPS) I like the little shields you've used but move to the nano sized Arduino after the breadboard works You say you have so rough edges with your code. If you post it some place (github.com, or just a file attachment here) Anyways if you post it I'll do what I can to clean it up and fix any problems. I'm wondering if you've addressed things like wrap around where the clock goes to zero or if you maybe have problem with race conditions in interrupt handers or something related to that. I have an Arduino attached to my iMac as I type. I know a bit about software but little about control theory and I'm trying to get a PID controller to be stable. The darn thing just runs away, literally, (t's a mobile robot.) The good thing about placing 99% of the functionality in software like you did is that your GPSDO can be improved quickly once a few experts look at it and start testing it. Already I am thinking about a real-time graphic display. It would be easy to add an LCD display to your GPSDO. And then there are better DACs and ADCs that are easy to connect to the Arunino's I2C bus Thanks again for sharing this On Tue, Feb 11, 2014 at 10:23 AM, Lars Walenius lars.walen...@hotmail.com wrote: I have long thought I should make my first post to the Time-Nuts forum. Being very grateful to everything I learned here. I have tried to attach a picture showing one of my two Arduino GPSDO Shields . The first one I put together in 2011. It only needs two HCMOS circuits (HC390+HC4046), one diode and passive components. Still it has 1nsec resolution. From the simplified schematic it can be seen that the TIC uses a HC4046 very similar to the Shera controller but instead of using a digital counter I just added a diode and RC-net that goes directly into one of the 10-bit AD channels. So the TIC has about 1nsec resolution and 1usec range when the HC4046 is fed with 1MHz from the HC390. The linearity of the TIC is quite good as I use the 1.1Volt ADC range. 500ns gives a reading of about 530 if 1000ns is a reading of 1000. See also the picture that shows a hanging bridge measured with the board.
Re: [time-nuts] Software for Brilliant Instruments B1220?
Hello Richard, Do you mind telling us how far that set you back? I did a quick archive search - I found a post where Shalom stated the BI220 cost: *BI220 is $2,950* They are local to me - so I am going to check out this piece of equipment too - looks like a good/great choice for doing the performance metric measurements that we do in our 'hobby'. Thanks for posting this. Best Regards, John Westmoreland On Sat, Mar 1, 2014 at 10:11 AM, rnks1...@yahoo.com wrote: Contact Brilliant Instruments (4088660426). I was at the office yesterday loading the new version that they just released on my TIA's and can tell you The new software works beautifully. They are amazing to work with, being the little guy on the block making amazing devices and all. Ask for Shalom or Daniel and I am sure they can get you set up and counting. Rob Sent from my Verizon Wireless BlackBerry -Original Message- From: Richard Parrish calc...@swbell.net Sender: time-nuts-boun...@febo.com Date: Sat, 1 Mar 2014 11:55:09 To: time-nuts@febo.com Reply-To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: [time-nuts] Software for Brilliant Instruments B1220? Does anyone have access to a copy of the software for the Brilliant Instruments B1220? I just purchased one off of eBay and, of course, they don't have it. Thanks, Richard Parrish calc...@swbell.net ___ 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] FE-5680A sweep range setting
On 3/01/14 11:35 AM, Magnus Danielson wrote: On 24/02/14 19:14, Paul Berger wrote: A couple further observations, to make life easier when adjusting C245 you can unplug the top card and move it aside, the CVXO will lock without it, but you will not have the 10MHz to monitor, but you can monitor the CVXO output instead. On the 6 pin connector you will see a 1 near the outer long edge of the second card, the CVXO output appears on pin 5 of this connector and on mine, it locks at 50.25505808 MHz according to my 5335A. I also noted that when the 5680A is well warmed up it sweeps through a much smaller range. In that case it would be good if the mid voltage would be established, so that once lock have been achieved, further trimming can be done until the VCXO steering is in the middle of the range. That would make sure there is plenty of margin to either end, rather than sitting on the edge and just barely lock. Cheers, Magnus ___ 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. After some careful looking around, I determined that this C245 that we are adjusting is part of an LC tank in one leg of the crystal. The one that I am having trouble with definitely has a fault in the VCXO oscillator it seems to want to start up up at about 50% of the desired frequency with a very small noisey signal, but if I touch almost anything around the crystal it snap into the right frequency range, with a nice strong, clean sine wave and locks rather quickly. I am finding it hard to trace out the circuit as this little card has components on both sides of it, and to make matters worse seems to be multi layer as well. I have set it aside for now but will go back to it later. I thought it was a little odd that these do not have a block of insulation over the bulb, does this matter? The other thing that is different about the two that I just got, from my first one is, these seem to be using an AD9830A synthesizer chip to generate the 10MHz output signal. There is a PIC beside which likely controls it and the PIC is connected to a RS-232 level converter chip however the external side of the RS232 chip is currently not connected to anything, but that can be quickly remedied. Paul. ___ 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] Why using HP5370 ext-ref is (maybe) a bad idea
In message CAE3hgTd5UDz_-T5mvgBarYYyuLwn=+00p1fho2fs+t1p1xd...@mail.gmail.com , Brian Lloyd writes: Instead of using the external reference input, any thoughts on actually disciplining the internal OCXO to bypass the problem? The end result would be no different than using ext-ref. Right now I think the best approach to smear the error out, is to run ext-ref from a frequency which is well-known, but not synchronous with the input signals, for instance from a synth like the 3336 or a carefully mis-tuned GPSDO The EFC pin on the OCXO in the 5370 is grounded in a way that makes it quite hard to unground. -- 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.
Re: [time-nuts] Software for Brilliant Instruments B1220?
I made an offer of $900 on ebay. They still have two left. Thanks, Richard Parrish calc...@swbell.net Cal Center Inc 1622 Griffith Ave Terrell, Texas 75160-4905 214-577-3515 -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of John C. Westmoreland, P.E. Sent: Saturday, March 01, 2014 2:45 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Software for Brilliant Instruments B1220? Hello Richard, Do you mind telling us how far that set you back? I did a quick archive search - I found a post where Shalom stated the BI220 cost: *BI220 is $2,950* They are local to me - so I am going to check out this piece of equipment too - looks like a good/great choice for doing the performance metric measurements that we do in our 'hobby'. Thanks for posting this. Best Regards, John Westmoreland On Sat, Mar 1, 2014 at 10:11 AM, rnks1...@yahoo.com wrote: Contact Brilliant Instruments (4088660426). I was at the office yesterday loading the new version that they just released on my TIA's and can tell you The new software works beautifully. They are amazing to work with, being the little guy on the block making amazing devices and all. Ask for Shalom or Daniel and I am sure they can get you set up and counting. Rob Sent from my Verizon Wireless BlackBerry -Original Message- From: Richard Parrish calc...@swbell.net Sender: time-nuts-boun...@febo.com Date: Sat, 1 Mar 2014 11:55:09 To: time-nuts@febo.com Reply-To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: [time-nuts] Software for Brilliant Instruments B1220? Does anyone have access to a copy of the software for the Brilliant Instruments B1220? I just purchased one off of eBay and, of course, they don't have it. Thanks, Richard Parrish calc...@swbell.net ___ 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] Software for Brilliant Instruments B1220?
Opps, forgot, I also have the BI200's so the software may be slightly different, but I suspect it would work. -Rob- Sent from my Verizon Wireless BlackBerry -Original Message- From: Richard Parrish calc...@swbell.net Sender: time-nuts-boun...@febo.com Date: Sat, 1 Mar 2014 15:36:44 To: 'Discussion of precise time and frequency measurement'time-nuts@febo.com Reply-To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] Software for Brilliant Instruments B1220? I made an offer of $900 on ebay. They still have two left. Thanks, Richard Parrish calc...@swbell.net Cal Center Inc 1622 Griffith Ave Terrell, Texas 75160-4905 214-577-3515 -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of John C. Westmoreland, P.E. Sent: Saturday, March 01, 2014 2:45 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Software for Brilliant Instruments B1220? Hello Richard, Do you mind telling us how far that set you back? I did a quick archive search - I found a post where Shalom stated the BI220 cost: *BI220 is $2,950* They are local to me - so I am going to check out this piece of equipment too - looks like a good/great choice for doing the performance metric measurements that we do in our 'hobby'. Thanks for posting this. Best Regards, John Westmoreland On Sat, Mar 1, 2014 at 10:11 AM, rnks1...@yahoo.com wrote: Contact Brilliant Instruments (4088660426). I was at the office yesterday loading the new version that they just released on my TIA's and can tell you The new software works beautifully. They are amazing to work with, being the little guy on the block making amazing devices and all. Ask for Shalom or Daniel and I am sure they can get you set up and counting. Rob Sent from my Verizon Wireless BlackBerry -Original Message- From: Richard Parrish calc...@swbell.net Sender: time-nuts-boun...@febo.com Date: Sat, 1 Mar 2014 11:55:09 To: time-nuts@febo.com Reply-To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: [time-nuts] Software for Brilliant Instruments B1220? Does anyone have access to a copy of the software for the Brilliant Instruments B1220? I just purchased one off of eBay and, of course, they don't have it. Thanks, Richard Parrish calc...@swbell.net ___ 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] FTS 2000A
Hi Magnus That is not what I said. Bert In a message dated 3/1/2014 10:39:30 A.M. Eastern Standard Time, mag...@rubidium.dyndns.org writes: Hi Bert, On 14/02/14 17:55, ewkeh...@aol.com wrote: Attached the innards of a FTS 2000A. The unit obviously does not have a thermal fuse. Solder had melted and the XTAL was loose inside. Do not know what happened since I got it that way Bert Kehren Thanks for sharing! I rarely say it, but now it applies: YUCK! Cheers, Magnus ___ 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] Arduino GPSDO with 1ns res TIC
Hi Magnus You are correct in a way. The code is more complicated than it should have been. The first row with comment “corr for time” is the I-term. The second row that integrates the frequency offset is the P-term and could have been just proportional to the time offset I understand now (I have thought of it before but totally forgot it). As I choosed to work with integers I have to scale the values to avoid truncation errors (that I still get with large time constants ☹. Probably it would be better to use floating point calculations. Lars Från: Magnus Danielson Hej Lars, Impressive build in all it's simplicity. Your filtering equations look strange. Rather than having a PI loop it looks like both the P and I branch integrates. I'm also unclear about the loop gain changes by the pre-filter averager. Will have to look more at your code. Cheers, Magnus On 12/02/14 23:10, Lars Walenius wrote: I have just changed all my Swedish comments in my source code and attached it. I also copied the text to a Word-file so everybody can see it without the Arduino Environment. The Control loop (“PI-loop”) is more or less just two lines that you find approximately in the middle of the file (page 13 in Word-file). Check the two lines with comment: Corr for time respectively Corr for frequency. ___ 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] Why using HP5370 ext-ref is (maybe) a bad idea
not being able to get to my two dead 5370Bs is there enough clearance to
allow for stacking capes ? If not the interface could be a 'horizontal'
implementation. Another one that just came to mind is have holes that
would allow one to put a metal can over the digital blocks / capes /
boards. Holes would go to ground.
On Sat, Mar 1, 2014 at 11:02 AM, John Seamons j...@jks.com wrote:
On Mar 2, 2014, at 7:05 AM, Pete Lancashire p...@petelancashire.com
wrote:
Idea. On the next go around for the board put the copper down and holes
for
a couple small daughter cards and any support logic needed to interface
with the BBB.
The the only additional cost would be limited to the daughter board I/O
since my guess it would be SMT hence a bit hard to leave it unpopulated.
Good idea. Also the Beagle spec allows for multiple, stacked interface
boards ('capes' they call them). So for a backwards compatible solution an
experimental GPSDO + backup power cape could be interposed between the
Beagle and 5370 board. I say experimental because I have no idea if any of
the SDGPS projects out there would be ultimately suitable for a DO.
This brings up a question I have about how the PPS edge is actually
derived by a GPS receiver. Does it originally come from the NAV data stream
and then get corrected by the (fixed-mode) positioning solution to account
for transmission/system delays? I know about the issue of alignment with
the VCTCXO clock, but I'm talking about upstream of that.
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Re: [time-nuts] Arduino GPSDO with 1ns res TIC
Hej Lars, On 01/03/14 23:09, Lars Walenius wrote: Hi Magnus You are correct in a way. The code is more complicated than it should have been. Well, there is potential for improvements. The first row with comment “corr for time” is the I-term. OK. The second row that integrates the frequency offset is the P-term and could have been just proportional to the time offset I understand now (I have thought of it before but totally forgot it). Well, as it says now it is dacValue = dacValue + I_contribution dacValue = dacValue + P_contribution rather than I = I + I_contribution dacValue = I + P_contribution The dacValue you create will integrate both the I and P contributions. However, that's not what your code is doing. The P-contribution is really a frequency input rather than proportional time/phase input. That is correct to integrate to get P-ish. A more direct way would be to remove the differentiating of the input and remove the integration on the output. That would make the code clearer about what's going on. As I choosed to work with integers I have to scale the values to avoid truncation errors (that I still get with large time constants ☹. Probably it would be better to use floating point calculations. You need to use long enough integers for it to work. Integer scaling is a bitch, but if you do it right, it can work very well for you. Personally, I'm lazy and just throw a ton of bits onto it, turns out it is cheap and I can worry about other parts of the design, and there is plenty of those to go around anyway. Cheers, Magnus ___ 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] Why using HP5370 ext-ref is (maybe) a bad idea
Hi,
Internally you typically run a 1 ms frame on everything. You integrate a
cycle of C/A code on each channel, sample state on all channels with the
1 ms clock and the solution will disclose the time-error of that 1 ms
clock so knowing how a 1 PPS relates to the 1 ms clock is fairly
trivial. The resolution will naturally be that of the core-clock, and
ones the delay for the right 1 ms frame has been setup, the PPS error
compared to the solution is known and you can calculate the sawtooth
if you care about it.
PPS as such is not in the GPS signal, rather all the time-info you need
to create it.
Cheers,
Magnus
On 01/03/14 20:06, Bob Camp wrote:
Hi
They run an NCO (drop / add pulses) to generate the PPS off of the TCXO. The
amount of adjustment is a function of the solution they derive from the GPS
messages. In some cases they do a solution, and correct the *next* edge to that
solution. In other chip sets the solution and the edge come out at the same
time.
Bob
On Mar 1, 2014, at 2:02 PM, John Seamons j...@jks.com wrote:
On Mar 2, 2014, at 7:05 AM, Pete Lancashire p...@petelancashire.com wrote:
Idea. On the next go around for the board put the copper down and holes for
a couple small daughter cards and any support logic needed to interface
with the BBB.
The the only additional cost would be limited to the daughter board I/O
since my guess it would be SMT hence a bit hard to leave it unpopulated.
Good idea. Also the Beagle spec allows for multiple, stacked interface boards
('capes' they call them). So for a backwards compatible solution an
experimental GPSDO + backup power cape could be interposed between the Beagle
and 5370 board. I say experimental because I have no idea if any of the SDGPS
projects out there would be ultimately suitable for a DO.
This brings up a question I have about how the PPS edge is actually derived by
a GPS receiver. Does it originally come from the NAV data stream and then get
corrected by the (fixed-mode) positioning solution to account for
transmission/system delays? I know about the issue of alignment with the VCTCXO
clock, but I'm talking about upstream of that.
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Re: [time-nuts] Why using HP5370 ext-ref is (maybe) a bad idea
On 01/03/14 22:38, Poul-Henning Kamp wrote: In message CAE3hgTd5UDz_-T5mvgBarYYyuLwn=+00p1fho2fs+t1p1xd...@mail.gmail.com , Brian Lloyd writes: Instead of using the external reference input, any thoughts on actually disciplining the internal OCXO to bypass the problem? The end result would be no different than using ext-ref. Right now I think the best approach to smear the error out, is to run ext-ref from a frequency which is well-known, but not synchronous with the input signals, for instance from a synth like the 3336 or a carefully mis-tuned GPSDO Would work if integer cycles is covered over the measurement time such that samples is taken spread over the 100 ns reference cycle. The EFC pin on the OCXO in the 5370 is grounded in a way that makes it quite hard to unground. Kapton tape into the connector, a wire soldered to EFC on the 10811? Cheers, Magnus ___ 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] FTS 2000A
Hi Bert, I guess you said something unprintable. Cheers, Magnus On 01/03/14 23:05, ewkeh...@aol.com wrote: Hi Magnus That is not what I said. Bert In a message dated 3/1/2014 10:39:30 A.M. Eastern Standard Time, mag...@rubidium.dyndns.org writes: Hi Bert, On 14/02/14 17:55, ewkeh...@aol.com wrote: Attached the innards of a FTS 2000A. The unit obviously does not have a thermal fuse. Solder had melted and the XTAL was loose inside. Do not know what happened since I got it that way Bert Kehren Thanks for sharing! I rarely say it, but now it applies: YUCK! Cheers, Magnus ___ 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] Another atomic clock question
There are WWVB clocks with serial output. Arcron made one that I added linux ntp support for some years back. http://www.atomictimeclock.com/radsynarcron.htm http://www.eecis.udel.edu/~mills/ntp/html/drivers/driver27.html As I recall, it was under $100, quite nicely styled, and is sitting here on my desk. (Reception on the East Coast can be spotty, so I've switched to standard internet net time source). On Mon, Feb 24, 2014 at 7:44 AM, Bob Camp li...@rtty.us wrote: Hi Ok, so 0.1 second at the sync point is indeed a reasonable estimate. If that's all you need to deal with (you correct out the crystal offset one way or the other) then: At 1 day you have 11.5 ppm accuracy. Roughly a 100 Hz beat note with WWV at 10 MHz. At 10 days you have 1.15 ppm. Roughly a 1 Hz beat note at 10 MHz. At 100 days you have 0.115 ppm. That would be about a 10 second period beat note. None of that is to say that a beat note is all there is to getting accuracy off of WWV or that the two approaches deliver the same net accuracy. Yes I've done the 10 second beat thing, it can be done with care and a good stable WWV signal. Bob On Feb 23, 2014, at 5:21 PM, Tom Van Baak t...@leapsecond.com wrote: Now that you have brought up this subject, do you know of any way to use these LaCrosse clocks to calibrate frequency standards? I suggest using a direct electric (1.5 VDC high-Z) or indirect magnetic (high gain) pickup on the coil to get the +/- pulse per second. Compare this time with your local frequency standard and over several days you should get accuracy better than 10 ms per day (1e-7). Here's an example of a raw phase plot: http://leapsecond.com/pages/Junghans/ /tvb ___ 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] Arduino GPSDO with 1ns res TIC
Magnus, The good thing about Lars posting his code is that if you think you see an improvement you can make it and test your idea. I intend to start doing just that but Chinese parts take about 30 days to get here and I'll just have to wait. My first steps will be to make the software vary easy to understand, to verify and modify. I'll likely post my version to GitHub. BTW I think P terms do integrate in a way because it's a correction term you apply to the current DAC value. The current DAC value is the sum of all the corrections in the past.So it may look like integration. With luck this could snowball. If it works well more people will use it and with more users, some of them will think of improvements that make it work better. On Sat, Mar 1, 2014 at 12:29 PM, Magnus Danielson mag...@rubidium.dyndns.org wrote: Hej Lars, Impressive build in all it's simplicity. Your filtering equations look strange. Rather than having a PI loop it looks like both the P and I branch integrates. I'm also unclear about the loop gain changes by the pre-filter averager. Will have to look more at your code. Cheers, Magnus -- Chris Albertson Redondo Beach, California ___ 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] FTS 2000A
that's right In a message dated 3/1/2014 7:26:07 P.M. Eastern Standard Time, mag...@rubidium.dyndns.org writes: Hi Bert, I guess you said something unprintable. Cheers, Magnus On 01/03/14 23:05, ewkeh...@aol.com wrote: Hi Magnus That is not what I said. Bert In a message dated 3/1/2014 10:39:30 A.M. Eastern Standard Time, mag...@rubidium.dyndns.org writes: Hi Bert, On 14/02/14 17:55, ewkeh...@aol.com wrote: Attached the innards of a FTS 2000A. The unit obviously does not have a thermal fuse. Solder had melted and the XTAL was loose inside. Do not know what happened since I got it that way Bert Kehren Thanks for sharing! I rarely say it, but now it applies: YUCK! Cheers, Magnus ___ 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] Another atomic clock question
All this is very interesting. However, my interest is frequency. In other words, I want to know that my standard oscillators are as close to desired frequency as possible, and how close that turns out to be. Yes, the Internet gives me time of day as close as I care to know. I have an 'atomic' clock from LaCrosse that resets itself nightly, although it's fussy about where in the house I put it. If I put it where I'd like, it won't receive WWVB, so I put it across the room. I called the company inquiring about augmenting the internal antenna but they were of no help. While watching the clock and listening to WWV, it seems the clock is a fraction of a second behind. Even that doesn't matter, but calibrating the counter time base is another kind of thing. I am trying to understand how this is done. Should I ever get a rubidium standard, I'd want to check its calibration, and that's not a trivial exercise. Bob On Saturday, March 1, 2014 4:56 PM, Paul Alfille paul.alfi...@gmail.com wrote: There are WWVB clocks with serial output. Arcron made one that I added linux ntp support for some years back. http://www.atomictimeclock.com/radsynarcron.htm http://www.eecis.udel.edu/~mills/ntp/html/drivers/driver27.html As I recall, it was under $100, quite nicely styled, and is sitting here on my desk. (Reception on the East Coast can be spotty, so I've switched to standard internet net time source). On Mon, Feb 24, 2014 at 7:44 AM, Bob Camp li...@rtty.us wrote: Hi Ok, so 0.1 second at the sync point is indeed a reasonable estimate. If that's all you need to deal with (you correct out the crystal offset one way or the other) then: At 1 day you have 11.5 ppm accuracy. Roughly a 100 Hz beat note with WWV at 10 MHz. At 10 days you have 1.15 ppm. Roughly a 1 Hz beat note at 10 MHz. At 100 days you have 0.115 ppm. That would be about a 10 second period beat note. None of that is to say that a beat note is all there is to getting accuracy off of WWV or that the two approaches deliver the same net accuracy. Yes I've done the 10 second beat thing, it can be done with care and a good stable WWV signal. Bob On Feb 23, 2014, at 5:21 PM, Tom Van Baak t...@leapsecond.com wrote: Now that you have brought up this subject, do you know of any way to use these LaCrosse clocks to calibrate frequency standards? I suggest using a direct electric (1.5 VDC high-Z) or indirect magnetic (high gain) pickup on the coil to get the +/- pulse per second. Compare this time with your local frequency standard and over several days you should get accuracy better than 10 ms per day (1e-7). Here's an example of a raw phase plot: http://leapsecond.com/pages/Junghans/ /tvb ___ 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] Another atomic clock question
Hi If all you need is frequency to 0.1 ppm, then a zero beat with WWV under good conditions will take care of your needs. If you need 0.1 ppb then it’s going to be harder to do. I’m assuming you are already into the “harder” category and WWV does not do what you are after. Like it or not time and frequency are joined at the hip. If you have trouble with one, it will show up in the other. If you want a “pure” frequency reference, you really only have one option - get a cesium beam standard and plan to replace the tube every so often. Even if you have one, there are still tweaks you would need to do to be *sure* it’s right. That’s mostly hard in the bank account department. You’ll spend more on the Cs than on a car. The only practical / cheap way to get accurate frequency in your basement is by doing a time comparison. There are lots of sources of accurate time out there. Setting up for a time comparison is really no more difficult than setting up for a good frequency comparison. Both take some care and some time. There’s no free lunch. These days, GPS is probably the best way to get the job done. There are $100 (ish) boxes on the auction sites that will do it all for you. Bob On Mar 1, 2014, at 9:04 PM, Bob Albert bob91...@yahoo.com wrote: All this is very interesting. However, my interest is frequency. In other words, I want to know that my standard oscillators are as close to desired frequency as possible, and how close that turns out to be. Yes, the Internet gives me time of day as close as I care to know. I have an 'atomic' clock from LaCrosse that resets itself nightly, although it's fussy about where in the house I put it. If I put it where I'd like, it won't receive WWVB, so I put it across the room. I called the company inquiring about augmenting the internal antenna but they were of no help. While watching the clock and listening to WWV, it seems the clock is a fraction of a second behind. Even that doesn't matter, but calibrating the counter time base is another kind of thing. I am trying to understand how this is done. Should I ever get a rubidium standard, I'd want to check its calibration, and that's not a trivial exercise. Bob On Saturday, March 1, 2014 4:56 PM, Paul Alfille paul.alfi...@gmail.com wrote: There are WWVB clocks with serial output. Arcron made one that I added linux ntp support for some years back. http://www.atomictimeclock.com/radsynarcron.htm http://www.eecis.udel.edu/~mills/ntp/html/drivers/driver27.html As I recall, it was under $100, quite nicely styled, and is sitting here on my desk. (Reception on the East Coast can be spotty, so I've switched to standard internet net time source). On Mon, Feb 24, 2014 at 7:44 AM, Bob Camp li...@rtty.us wrote: Hi Ok, so 0.1 second at the sync point is indeed a reasonable estimate. If that's all you need to deal with (you correct out the crystal offset one way or the other) then: At 1 day you have 11.5 ppm accuracy. Roughly a 100 Hz beat note with WWV at 10 MHz. At 10 days you have 1.15 ppm. Roughly a 1 Hz beat note at 10 MHz. At 100 days you have 0.115 ppm. That would be about a 10 second period beat note. None of that is to say that a beat note is all there is to getting accuracy off of WWV or that the two approaches deliver the same net accuracy. Yes I've done the 10 second beat thing, it can be done with care and a good stable WWV signal. Bob On Feb 23, 2014, at 5:21 PM, Tom Van Baak t...@leapsecond.com wrote: Now that you have brought up this subject, do you know of any way to use these LaCrosse clocks to calibrate frequency standards? I suggest using a direct electric (1.5 VDC high-Z) or indirect magnetic (high gain) pickup on the coil to get the +/- pulse per second. Compare this time with your local frequency standard and over several days you should get accuracy better than 10 ms per day (1e-7). Here's an example of a raw phase plot: http://leapsecond.com/pages/Junghans/ /tvb ___ 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
Re: [time-nuts] Another atomic clock question
Hi Bob, Everything about time frequency is simply a matter of degree, of decimals points. If all you require is 1 second accuracy then any old WWVB RC clock will work. If you want 0.1 second, or 10 ms, or 1 ms accuracy a PC running NTP should work. As you push closer to the microsecond level you need a correspondingly better internal stable frequency source (e.g., rubidium) or external accurate time source (e.g., GPS). Most of us use GPS one way or another, achieving 100 ns accuracy with no effort and 10 ns with extreme effort. Listening to WWV makes a nice example. Where I am near Seattle, say 1000 miles from NIST, the radio wave delay from Ft Collins (due to speed of light, 1 ns/foot, or 5 us/mile) is about 5 ms. The delay from the WWV radio speaker to my ear (due to the speed of sound, 1 ms/foot, or 5 s/mile) is about 5 ms. /tvb - Original Message - From: Bob Albert bob91...@yahoo.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Saturday, March 01, 2014 6:04 PM Subject: Re: [time-nuts] Another atomic clock question All this is very interesting. However, my interest is frequency. In other words, I want to know that my standard oscillators are as close to desired frequency as possible, and how close that turns out to be. Yes, the Internet gives me time of day as close as I care to know. I have an 'atomic' clock from LaCrosse that resets itself nightly, although it's fussy about where in the house I put it. If I put it where I'd like, it won't receive WWVB, so I put it across the room. I called the company inquiring about augmenting the internal antenna but they were of no help. While watching the clock and listening to WWV, it seems the clock is a fraction of a second behind. Even that doesn't matter, but calibrating the counter time base is another kind of thing. I am trying to understand how this is done. Should I ever get a rubidium standard, I'd want to check its calibration, and that's not a trivial exercise. Bob On Saturday, March 1, 2014 4:56 PM, Paul Alfille paul.alfi...@gmail.com wrote: There are WWVB clocks with serial output. Arcron made one that I added linux ntp support for some years back. http://www.atomictimeclock.com/radsynarcron.htm http://www.eecis.udel.edu/~mills/ntp/html/drivers/driver27.html As I recall, it was under $100, quite nicely styled, and is sitting here on my desk. (Reception on the East Coast can be spotty, so I've switched to standard internet net time source). On Mon, Feb 24, 2014 at 7:44 AM, Bob Camp li...@rtty.us wrote: Hi Ok, so 0.1 second at the sync point is indeed a reasonable estimate. If that's all you need to deal with (you correct out the crystal offset one way or the other) then: At 1 day you have 11.5 ppm accuracy. Roughly a 100 Hz beat note with WWV at 10 MHz. At 10 days you have 1.15 ppm. Roughly a 1 Hz beat note at 10 MHz. At 100 days you have 0.115 ppm. That would be about a 10 second period beat note. None of that is to say that a beat note is all there is to getting accuracy off of WWV or that the two approaches deliver the same net accuracy. Yes I've done the 10 second beat thing, it can be done with care and a good stable WWV signal. Bob On Feb 23, 2014, at 5:21 PM, Tom Van Baak t...@leapsecond.com wrote: Now that you have brought up this subject, do you know of any way to use these LaCrosse clocks to calibrate frequency standards? I suggest using a direct electric (1.5 VDC high-Z) or indirect magnetic (high gain) pickup on the coil to get the +/- pulse per second. Compare this time with your local frequency standard and over several days you should get accuracy better than 10 ms per day (1e-7). Here's an example of a raw phase plot: http://leapsecond.com/pages/Junghans/ /tvb ___ 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] Another atomic clock question
Careful where you step. You may just get sucked into time nuts and it never stops. Get a good crystal, then its an RB, next you know your paying shipping for a 100 Lbs Cesium. Evil stuff. Or you can just skip all the distractions and get a good GPSDO. Not as much fun learning on the way. But depends on your end goal. Regards Paul WB8TSL On Sat, Mar 1, 2014 at 9:04 PM, Bob Albert bob91...@yahoo.com wrote: All this is very interesting. However, my interest is frequency. In other words, I want to know that my standard oscillators are as close to desired frequency as possible, and how close that turns out to be. Yes, the Internet gives me time of day as close as I care to know. I have an 'atomic' clock from LaCrosse that resets itself nightly, although it's fussy about where in the house I put it. If I put it where I'd like, it won't receive WWVB, so I put it across the room. I called the company inquiring about augmenting the internal antenna but they were of no help. While watching the clock and listening to WWV, it seems the clock is a fraction of a second behind. Even that doesn't matter, but calibrating the counter time base is another kind of thing. I am trying to understand how this is done. Should I ever get a rubidium standard, I'd want to check its calibration, and that's not a trivial exercise. Bob On Saturday, March 1, 2014 4:56 PM, Paul Alfille paul.alfi...@gmail.com wrote: There are WWVB clocks with serial output. Arcron made one that I added linux ntp support for some years back. http://www.atomictimeclock.com/radsynarcron.htm http://www.eecis.udel.edu/~mills/ntp/html/drivers/driver27.html As I recall, it was under $100, quite nicely styled, and is sitting here on my desk. (Reception on the East Coast can be spotty, so I've switched to standard internet net time source). On Mon, Feb 24, 2014 at 7:44 AM, Bob Camp li...@rtty.us wrote: Hi Ok, so 0.1 second at the sync point is indeed a reasonable estimate. If that's all you need to deal with (you correct out the crystal offset one way or the other) then: At 1 day you have 11.5 ppm accuracy. Roughly a 100 Hz beat note with WWV at 10 MHz. At 10 days you have 1.15 ppm. Roughly a 1 Hz beat note at 10 MHz. At 100 days you have 0.115 ppm. That would be about a 10 second period beat note. None of that is to say that a beat note is all there is to getting accuracy off of WWV or that the two approaches deliver the same net accuracy. Yes I've done the 10 second beat thing, it can be done with care and a good stable WWV signal. Bob On Feb 23, 2014, at 5:21 PM, Tom Van Baak t...@leapsecond.com wrote: Now that you have brought up this subject, do you know of any way to use these LaCrosse clocks to calibrate frequency standards? I suggest using a direct electric (1.5 VDC high-Z) or indirect magnetic (high gain) pickup on the coil to get the +/- pulse per second. Compare this time with your local frequency standard and over several days you should get accuracy better than 10 ms per day (1e-7). Here's an example of a raw phase plot: http://leapsecond.com/pages/Junghans/ /tvb ___ 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] Another atomic clock question
that WWV has some problem, the propagation path is not very stabile, therefore the arriving signal is phase modulated, if you look it for short time the phase modulation looks like frequency modulation it means the frequency is changing = not stabile, WWVB is a bit better since it ha a more stabile propagation path due to it's much lower frequency, 60kHz but there are al our nice switching mode power supplies which generating lots of concurrence for WWVB, so it is not so simple task to receive it clean 73 KJ6UHN Alex On 3/1/2014 6:31 PM, Tom Van Baak wrote: Hi Bob, Everything about time frequency is simply a matter of degree, of decimals points. If all you require is 1 second accuracy then any old WWVB RC clock will work. If you want 0.1 second, or 10 ms, or 1 ms accuracy a PC running NTP should work. As you push closer to the microsecond level you need a correspondingly better internal stable frequency source (e.g., rubidium) or external accurate time source (e.g., GPS). Most of us use GPS one way or another, achieving 100 ns accuracy with no effort and 10 ns with extreme effort. Listening to WWV makes a nice example. Where I am near Seattle, say 1000 miles from NIST, the radio wave delay from Ft Collins (due to speed of light, 1 ns/foot, or 5 us/mile) is about 5 ms. The delay from the WWV radio speaker to my ear (due to the speed of sound, 1 ms/foot, or 5 s/mile) is about 5 ms. /tvb - Original Message - From: Bob Albert bob91...@yahoo.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Saturday, March 01, 2014 6:04 PM Subject: Re: [time-nuts] Another atomic clock question All this is very interesting. However, my interest is frequency. In other words, I want to know that my standard oscillators are as close to desired frequency as possible, and how close that turns out to be. Yes, the Internet gives me time of day as close as I care to know. I have an 'atomic' clock from LaCrosse that resets itself nightly, although it's fussy about where in the house I put it. If I put it where I'd like, it won't receive WWVB, so I put it across the room. I called the company inquiring about augmenting the internal antenna but they were of no help. While watching the clock and listening to WWV, it seems the clock is a fraction of a second behind. Even that doesn't matter, but calibrating the counter time base is another kind of thing. I am trying to understand how this is done. Should I ever get a rubidium standard, I'd want to check its calibration, and that's not a trivial exercise. Bob On Saturday, March 1, 2014 4:56 PM, Paul Alfille paul.alfi...@gmail.com wrote: There are WWVB clocks with serial output. Arcron made one that I added linux ntp support for some years back. http://www.atomictimeclock.com/radsynarcron.htm http://www.eecis.udel.edu/~mills/ntp/html/drivers/driver27.html As I recall, it was under $100, quite nicely styled, and is sitting here on my desk. (Reception on the East Coast can be spotty, so I've switched to standard internet net time source). On Mon, Feb 24, 2014 at 7:44 AM, Bob Camp li...@rtty.us wrote: Hi Ok, so 0.1 second at the sync point is indeed a reasonable estimate. If that's all you need to deal with (you correct out the crystal offset one way or the other) then: At 1 day you have 11.5 ppm accuracy. Roughly a 100 Hz beat note with WWV at 10 MHz. At 10 days you have 1.15 ppm. Roughly a 1 Hz beat note at 10 MHz. At 100 days you have 0.115 ppm. That would be about a 10 second period beat note. None of that is to say that a beat note is all there is to getting accuracy off of WWV or that the two approaches deliver the same net accuracy. Yes I've done the 10 second beat thing, it can be done with care and a good stable WWV signal. Bob On Feb 23, 2014, at 5:21 PM, Tom Van Baak t...@leapsecond.com wrote: Now that you have brought up this subject, do you know of any way to use these LaCrosse clocks to calibrate frequency standards? I suggest using a direct electric (1.5 VDC high-Z) or indirect magnetic (high gain) pickup on the coil to get the +/- pulse per second. Compare this time with your local frequency standard and over several days you should get accuracy better than 10 ms per day (1e-7). Here's an example of a raw phase plot: http://leapsecond.com/pages/Junghans/ /tvb ___ 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] Another atomic clock question
Hi With WWV you need to do it at the right time and the right frequency. There may not be a right combination every day. You want to do it when you have a stable path between you and them. That can (and does) happen, just not all the time. Bob On Mar 1, 2014, at 9:55 PM, Alex Pummer a...@pcscons.com wrote: that WWV has some problem, the propagation path is not very stabile, therefore the arriving signal is phase modulated, if you look it for short time the phase modulation looks like frequency modulation it means the frequency is changing = not stabile, WWVB is a bit better since it ha a more stabile propagation path due to it's much lower frequency, 60kHz but there are al our nice switching mode power supplies which generating lots of concurrence for WWVB, so it is not so simple task to receive it clean 73 KJ6UHN Alex On 3/1/2014 6:31 PM, Tom Van Baak wrote: Hi Bob, Everything about time frequency is simply a matter of degree, of decimals points. If all you require is 1 second accuracy then any old WWVB RC clock will work. If you want 0.1 second, or 10 ms, or 1 ms accuracy a PC running NTP should work. As you push closer to the microsecond level you need a correspondingly better internal stable frequency source (e.g., rubidium) or external accurate time source (e.g., GPS). Most of us use GPS one way or another, achieving 100 ns accuracy with no effort and 10 ns with extreme effort. Listening to WWV makes a nice example. Where I am near Seattle, say 1000 miles from NIST, the radio wave delay from Ft Collins (due to speed of light, 1 ns/foot, or 5 us/mile) is about 5 ms. The delay from the WWV radio speaker to my ear (due to the speed of sound, 1 ms/foot, or 5 s/mile) is about 5 ms. /tvb - Original Message - From: Bob Albert bob91...@yahoo.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Saturday, March 01, 2014 6:04 PM Subject: Re: [time-nuts] Another atomic clock question All this is very interesting. However, my interest is frequency. In other words, I want to know that my standard oscillators are as close to desired frequency as possible, and how close that turns out to be. Yes, the Internet gives me time of day as close as I care to know. I have an 'atomic' clock from LaCrosse that resets itself nightly, although it's fussy about where in the house I put it. If I put it where I'd like, it won't receive WWVB, so I put it across the room. I called the company inquiring about augmenting the internal antenna but they were of no help. While watching the clock and listening to WWV, it seems the clock is a fraction of a second behind. Even that doesn't matter, but calibrating the counter time base is another kind of thing. I am trying to understand how this is done. Should I ever get a rubidium standard, I'd want to check its calibration, and that's not a trivial exercise. Bob On Saturday, March 1, 2014 4:56 PM, Paul Alfille paul.alfi...@gmail.com wrote: There are WWVB clocks with serial output. Arcron made one that I added linux ntp support for some years back. http://www.atomictimeclock.com/radsynarcron.htm http://www.eecis.udel.edu/~mills/ntp/html/drivers/driver27.html As I recall, it was under $100, quite nicely styled, and is sitting here on my desk. (Reception on the East Coast can be spotty, so I've switched to standard internet net time source). On Mon, Feb 24, 2014 at 7:44 AM, Bob Camp li...@rtty.us wrote: Hi Ok, so 0.1 second at the sync point is indeed a reasonable estimate. If that's all you need to deal with (you correct out the crystal offset one way or the other) then: At 1 day you have 11.5 ppm accuracy. Roughly a 100 Hz beat note with WWV at 10 MHz. At 10 days you have 1.15 ppm. Roughly a 1 Hz beat note at 10 MHz. At 100 days you have 0.115 ppm. That would be about a 10 second period beat note. None of that is to say that a beat note is all there is to getting accuracy off of WWV or that the two approaches deliver the same net accuracy. Yes I've done the 10 second beat thing, it can be done with care and a good stable WWV signal. Bob On Feb 23, 2014, at 5:21 PM, Tom Van Baak t...@leapsecond.com wrote: Now that you have brought up this subject, do you know of any way to use these LaCrosse clocks to calibrate frequency standards? I suggest using a direct electric (1.5 VDC high-Z) or indirect magnetic (high gain) pickup on the coil to get the +/- pulse per second. Compare this time with your local frequency standard and over several days you should get accuracy better than 10 ms per day (1e-7). Here's an example of a raw phase plot: http://leapsecond.com/pages/Junghans/ /tvb ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow
Re: [time-nuts] Another atomic clock question
I am trying to understand how this is done. Should I ever get a rubidium standard, I'd want to check its calibration, and that's not a trivial exercise. If you assume your rubidium is stable, then it's pretty easy to check and/or calibrate. The trick is that you need someplace to stand. A PC running ntp is good long term. There is a tradeoff between good and long. Good is ambiguous, but both how-good is your PC clock and how good/accurate a measurement do you want are appropriate. Probably the simplest way is to get one of tvb's preprogrammed PICs. http://www.leapsecond.com/pic/picdiv.htm http://www.leapsecond.com/pic/picpet.htm One approach is to use a picDIV to make a PPS and then monitor that. If you have Linux, you can feed the PPS to a serial port. My hack for counting 60Hz will work fine at 1 Hz. http://www.megapathdsl.net/~hmurray/time-nuts/60Hz/60Hz.py Another approach is to use a picPET and connect a modem control signal from the monitoring PC to the Event input on the picPET. Then the data collection program grabs the time, flaps a modem control signal, grabs the time again, then grabs the text from the picPET and logs everything. -- These are my opinions. I hate spam. ___ 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] Another atomic clock question
Paul, as I said I just want to know how close my crystals are and be able to adjust them as well as they can be. I probably will never go rubidium (note that I qualified that) but still somewhere one has to decide where to set the frequency. I did WWV at 20 MHz for a beat of somewhat slower than one per second. I know the phase changes but probably not much in a few minutes, as the path length doesn't vary very quickly. And I don't need phase lock to them anyway. In the old days they had 25 MHz and even 30 MHz for a slight improvement in settability if not stability. Bob On Saturday, March 1, 2014 7:38 PM, Hal Murray hmur...@megapathdsl.net wrote: I am trying to understand how this is done. Should I ever get a rubidium standard, I'd want to check its calibration, and that's not a trivial exercise. If you assume your rubidium is stable, then it's pretty easy to check and/or calibrate. The trick is that you need someplace to stand. A PC running ntp is good long term. There is a tradeoff between good and long. Good is ambiguous, but both how-good is your PC clock and how good/accurate a measurement do you want are appropriate. Probably the simplest way is to get one of tvb's preprogrammed PICs. http://www.leapsecond.com/pic/picdiv.htm http://www.leapsecond.com/pic/picpet.htm One approach is to use a picDIV to make a PPS and then monitor that. If you have Linux, you can feed the PPS to a serial port. My hack for counting 60Hz will work fine at 1 Hz. http://www.megapathdsl.net/~hmurray/time-nuts/60Hz/60Hz.py Another approach is to use a picPET and connect a modem control signal from the monitoring PC to the Event input on the picPET. Then the data collection program grabs the time, flaps a modem control signal, grabs the time again, then grabs the text from the picPET and logs everything. -- These are my opinions. I hate spam. ___ 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] Peregrine Ends Prescalers
Hello All, I just found out this last week that Peregrine has decided to EOL all of their prescalers. Thought that could be of interest to some in the group. Regards, John W. ___ 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] Another atomic clock question
Here's a little anecdote that tells how far we have come in the last 50 years. I had the privilege of visiting a NASA lab in 64 I think it was. They showed us, I was with a student group, a setup with a scope a WWV receiver and a rotating transformer that would change the time on a clock one millisecond for every turn of a crank. The seconds output from the divider chain triggered a scope sweep and the vertical displayed the audio from WWV. The guy could turn the crank and position the start of the time tick on the left of the screen. Then he turned the crank to correct for light time delay. I think WWV was still in Maryland at that time. I don't remember exactly when they moved it to Colorado. Anyway, this was the master clock for tracking and telemetry for the manned space flights of that time. Regards. Max. K 4 O DS. Email: m...@maxsmusicplace.com Transistor site http://www.funwithtransistors.net Vacuum tube site: http://www.funwithtubes.net Woodworking site http://www.angelfire.com/electronic/funwithtubes/Woodworking/wwindex.html Music site: http://www.maxsmusicplace.com To subscribe to the fun with transistors group send an email to. funwithtransistors-subscr...@yahoogroups.com To subscribe to the fun with tubes group send an email to, funwithtubes-subscr...@yahoogroups.com To subscribe to the fun with wood group send a blank email to funwithwood-subscr...@yahoogroups.com - Original Message - From: paul swed paulsw...@gmail.com To: Bob Albert bob91...@yahoo.com; Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Saturday, March 01, 2014 8:33 PM Subject: Re: [time-nuts] Another atomic clock question Careful where you step. You may just get sucked into time nuts and it never stops. Get a good crystal, then its an RB, next you know your paying shipping for a 100 Lbs Cesium. Evil stuff. Or you can just skip all the distractions and get a good GPSDO. Not as much fun learning on the way. But depends on your end goal. Regards Paul WB8TSL On Sat, Mar 1, 2014 at 9:04 PM, Bob Albert bob91...@yahoo.com wrote: All this is very interesting. However, my interest is frequency. In other words, I want to know that my standard oscillators are as close to desired frequency as possible, and how close that turns out to be. Yes, the Internet gives me time of day as close as I care to know. I have an 'atomic' clock from LaCrosse that resets itself nightly, although it's fussy about where in the house I put it. If I put it where I'd like, it won't receive WWVB, so I put it across the room. I called the company inquiring about augmenting the internal antenna but they were of no help. While watching the clock and listening to WWV, it seems the clock is a fraction of a second behind. Even that doesn't matter, but calibrating the counter time base is another kind of thing. I am trying to understand how this is done. Should I ever get a rubidium standard, I'd want to check its calibration, and that's not a trivial exercise. Bob On Saturday, March 1, 2014 4:56 PM, Paul Alfille paul.alfi...@gmail.com wrote: There are WWVB clocks with serial output. Arcron made one that I added linux ntp support for some years back. http://www.atomictimeclock.com/radsynarcron.htm http://www.eecis.udel.edu/~mills/ntp/html/drivers/driver27.html As I recall, it was under $100, quite nicely styled, and is sitting here on my desk. (Reception on the East Coast can be spotty, so I've switched to standard internet net time source). On Mon, Feb 24, 2014 at 7:44 AM, Bob Camp li...@rtty.us wrote: Hi Ok, so 0.1 second at the sync point is indeed a reasonable estimate. If that's all you need to deal with (you correct out the crystal offset one way or the other) then: At 1 day you have 11.5 ppm accuracy. Roughly a 100 Hz beat note with WWV at 10 MHz. At 10 days you have 1.15 ppm. Roughly a 1 Hz beat note at 10 MHz. At 100 days you have 0.115 ppm. That would be about a 10 second period beat note. None of that is to say that a beat note is all there is to getting accuracy off of WWV or that the two approaches deliver the same net accuracy. Yes I've done the 10 second beat thing, it can be done with care and a good stable WWV signal. Bob On Feb 23, 2014, at 5:21 PM, Tom Van Baak t...@leapsecond.com wrote: Now that you have brought up this subject, do you know of any way to use these LaCrosse clocks to calibrate frequency standards? I suggest using a direct electric (1.5 VDC high-Z) or indirect magnetic (high gain) pickup on the coil to get the +/- pulse per second. Compare this time with your local frequency standard and over several days you should get accuracy better than 10 ms per day (1e-7). Here's an example of a raw phase plot: http://leapsecond.com/pages/Junghans/ /tvb ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to
Re: [time-nuts] Another atomic clock question
On Sat, Mar 1, 2014 at 8:05 PM, Bob Albert bob91...@yahoo.com wrote: Paul, as I said I just want to know how close my crystals are and be able to adjust them as well as they can be. I probably will never go rubidium (note that I qualified that) but still somewhere one has to decide where to set the frequency. I did WWV at 20 MHz for a beat of somewhat slower than one per second. I know the phase changes but probably not much in a few minutes, as the path length doesn't vary very quickly. And I don't need phase lock to them anyway. In the old days they had 25 MHz and even 30 MHz for a slight improvement in settability if not stability. Bob On Saturday, March 1, 2014 7:38 PM, Hal Murray hmur...@megapathdsl.net wrote: I am trying to understand how this is done. Should I ever get a rubidium standard, I'd want to check its calibration, and that's not a trivial exercise. If you assume your rubidium is stable, then it's pretty easy to check and/or calibrate. The trick is that you need someplace to stand. A PC running ntp is good long term. There is a tradeoff between good and long. Good is ambiguous, but both how-good is your PC clock and how good/accurate a measurement do you want are appropriate. Probably the simplest way is to get one of tvb's preprogrammed PICs. http://www.leapsecond.com/pic/picdiv.htm http://www.leapsecond.com/pic/picpet.htm One approach is to use a picDIV to make a PPS and then monitor that. If you have Linux, you can feed the PPS to a serial port. My hack for counting 60Hz will work fine at 1 Hz. http://www.megapathdsl.net/~hmurray/time-nuts/60Hz/60Hz.py Another approach is to use a picPET and connect a modem control signal from the monitoring PC to the Event input on the picPET. Then the data collection program grabs the time, flaps a modem control signal, grabs the time again, then grabs the text from the picPET and logs everything. -- These are my opinions. I hate spam. ___ 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. -- Chris Albertson Redondo Beach, California ___ 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] Another atomic clock question
On Sat, Mar 1, 2014 at 8:05 PM, Bob Albert bob91...@yahoo.com wrote: Paul, as I said I just want to know how close my crystals are and be able to adjust them as well as they can be. Don't say as well as can be that can get expensive and time consuming. You need to use numbers. Say and be able to adjust them at the 1E-8 level. Then you will get advice to just use WWV. But what if you need 10,000 times better? Then use GPS After that it starts getting harder but you still are not up to as well as they can be. I admit to a few years ago using a 50 cent TTL can oscillator as my lab standard The part was salvage from some junk and was good to about 5 digits accuracy. It worked actually better than I needed. My RF signal generator was from the 1960's with a hand turned dial to adjust the frequency. The TTL can let me calibrate the dial. I probably will never go rubidium (note that I qualified that) but still somewhere one has to decide where to set the frequency. I did WWV at 20 MHz for a beat of somewhat slower than one per second. I know the phase changes but probably not much in a few minutes, as the path length doesn't vary very quickly. And I don't need phase lock to them anyway. In the old days they had 25 MHz and even 30 MHz for a slight improvement in settability if not stability. Bob On Saturday, March 1, 2014 7:38 PM, Hal Murray hmur...@megapathdsl.net wrote: I am trying to understand how this is done. Should I ever get a rubidium standard, I'd want to check its calibration, and that's not a trivial exercise. If you assume your rubidium is stable, then it's pretty easy to check and/or calibrate. The trick is that you need someplace to stand. A PC running ntp is good long term. There is a tradeoff between good and long. Good is ambiguous, but both how-good is your PC clock and how good/accurate a measurement do you want are appropriate. Probably the simplest way is to get one of tvb's preprogrammed PICs. http://www.leapsecond.com/pic/picdiv.htm http://www.leapsecond.com/pic/picpet.htm One approach is to use a picDIV to make a PPS and then monitor that. If you have Linux, you can feed the PPS to a serial port. My hack for counting 60Hz will work fine at 1 Hz. http://www.megapathdsl.net/~hmurray/time-nuts/60Hz/60Hz.py Another approach is to use a picPET and connect a modem control signal from the monitoring PC to the Event input on the picPET. Then the data collection program grabs the time, flaps a modem control signal, grabs the time again, then grabs the text from the picPET and logs everything. -- These are my opinions. I hate spam. ___ 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. -- Chris Albertson Redondo Beach, California ___ 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] Another atomic clock question
Chris, Okay you want numbers. Well, I think 10 ppb or thereabouts should do it. Somewhere there is a discontinuity in accuracy plotted against cost and I don't want to cross that barrier just yet. If I can get 1 ppb without a big increase in cost, I'll take that. My need for this is nonexistent. I am only interested in doing it for the fun of seeing all zeros on the counter and having it give me that repeatedly. The pleasure of knowing I am as close as the equipment is capable is what I seek. I'm sure many time nuts feel the same. I am not interested in offering a calibration service or tracking spacecraft or measuring the diameter of the moon. How do I get accurate frequency from GPS? I have the same fetish regarding components, resistors and capacitors and inductors. I have lots of good meters but am always looking for a better one. I am trying to get six useful digits of voltage and resistance measurement and eventually want to do it with current as well. Not so sure about temperature, mass, and force. Once I get where I want to be, I'll probably go into basket weaving. Bob On Sunday, March 2, 2014 5:46 AM, Chris Albertson albertson.ch...@gmail.com wrote: On Sat, Mar 1, 2014 at 8:05 PM, Bob Albert bob91...@yahoo.com wrote: Paul, as I said I just want to know how close my crystals are and be able to adjust them as well as they can be. Don't say as well as can be that can get expensive and time consuming. You need to use numbers. Say and be able to adjust them at the 1E-8 level. Then you will get advice to just use WWV. But what if you need 10,000 times better? Then use GPS After that it starts getting harder but you still are not up to as well as they can be. I admit to a few years ago using a 50 cent TTL can oscillator as my lab standard The part was salvage from some junk and was good to about 5 digits accuracy. It worked actually better than I needed. My RF signal generator was from the 1960's with a hand turned dial to adjust the frequency. The TTL can let me calibrate the dial. I probably will never go rubidium (note that I qualified that) but still somewhere one has to decide where to set the frequency. I did WWV at 20 MHz for a beat of somewhat slower than one per second. I know the phase changes but probably not much in a few minutes, as the path length doesn't vary very quickly. And I don't need phase lock to them anyway. In the old days they had 25 MHz and even 30 MHz for a slight improvement in settability if not stability. Bob On Saturday, March 1, 2014 7:38 PM, Hal Murray hmur...@megapathdsl.net wrote: I am trying to understand how this is done. Should I ever get a rubidium standard, I'd want to check its calibration, and that's not a trivial exercise. If you assume your rubidium is stable, then it's pretty easy to check and/or calibrate. The trick is that you need someplace to stand. A PC running ntp is good long term. There is a tradeoff between good and long. Good is ambiguous, but both how-good is your PC clock and how good/accurate a measurement do you want are appropriate. Probably the simplest way is to get one of tvb's preprogrammed PICs. http://www.leapsecond.com/pic/picdiv.htm http://www.leapsecond.com/pic/picpet.htm One approach is to use a picDIV to make a PPS and then monitor that. If you have Linux, you can feed the PPS to a serial port. My hack for counting 60Hz will work fine at 1 Hz. http://www.megapathdsl.net/~hmurray/time-nuts/60Hz/60Hz.py Another approach is to use a picPET and connect a modem control signal from the monitoring PC to the Event input on the picPET. Then the data collection program grabs the time, flaps a modem control signal, grabs the time again, then grabs the text from the picPET and logs everything. -- These are my opinions. I hate spam. ___ 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. -- Chris Albertson Redondo Beach, California ___ 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] Another atomic clock question
Bob, I am curious, a week or so ago I sent you an email that gave links to some publications that would serve you very well in helping you to achieve your goals. Did you ever get that email and look at the linked PDF files ? ? ? ? BillWB6BNQ Bob Albert wrote: Chris, Okay you want numbers. Well, I think 10 ppb or thereabouts should do it. Somewhere there is a discontinuity in accuracy plotted against cost and I don't want to cross that barrier just yet. If I can get 1 ppb without a big increase in cost, I'll take that. My need for this is nonexistent. I am only interested in doing it for the fun of seeing all zeros on the counter and having it give me that repeatedly. The pleasure of knowing I am as close as the equipment is capable is what I seek. I'm sure many time nuts feel the same. I am not interested in offering a calibration service or tracking spacecraft or measuring the diameter of the moon. How do I get accurate frequency from GPS? I have the same fetish regarding components, resistors and capacitors and inductors. I have lots of good meters but am always looking for a better one. I am trying to get six useful digits of voltage and resistance measurement and eventually want to do it with current as well. Not so sure about temperature, mass, and force. Once I get where I want to be, I'll probably go into basket weaving. Bob On Sunday, March 2, 2014 5:46 AM, Chris Albertson albertson.ch...@gmail.com wrote: On Sat, Mar 1, 2014 at 8:05 PM, Bob Albert bob91...@yahoo.com wrote: Paul, as I said I just want to know how close my crystals are and be able to adjust them as well as they can be. Don't say as well as can be that can get expensive and time consuming. You need to use numbers. Say and be able to adjust them at the 1E-8 level. Then you will get advice to just use WWV. But what if you need 10,000 times better? Then use GPS After that it starts getting harder but you still are not up to as well as they can be. I admit to a few years ago using a 50 cent TTL can oscillator as my lab standard The part was salvage from some junk and was good to about 5 digits accuracy. It worked actually better than I needed. My RF signal generator was from the 1960's with a hand turned dial to adjust the frequency. The TTL can let me calibrate the dial. I probably will never go rubidium (note that I qualified that) but still somewhere one has to decide where to set the frequency. I did WWV at 20 MHz for a beat of somewhat slower than one per second. I know the phase changes but probably not much in a few minutes, as the path length doesn't vary very quickly. And I don't need phase lock to them anyway. In the old days they had 25 MHz and even 30 MHz for a slight improvement in settability if not stability. Bob On Saturday, March 1, 2014 7:38 PM, Hal Murray hmur...@megapathdsl.net wrote: I am trying to understand how this is done. Should I ever get a rubidium standard, I'd want to check its calibration, and that's not a trivial exercise. If you assume your rubidium is stable, then it's pretty easy to check and/or calibrate. The trick is that you need someplace to stand. A PC running ntp is good long term. There is a tradeoff between good and long. Good is ambiguous, but both how-good is your PC clock and how good/accurate a measurement do you want are appropriate. Probably the simplest way is to get one of tvb's preprogrammed PICs. http://www.leapsecond.com/pic/picdiv.htm http://www.leapsecond.com/pic/picpet.htm One approach is to use a picDIV to make a PPS and then monitor that. If you have Linux, you can feed the PPS to a serial port. My hack for counting 60Hz will work fine at 1 Hz. http://www.megapathdsl.net/~hmurray/time-nuts/60Hz/60Hz.py Another approach is to use a picPET and connect a modem control signal from the monitoring PC to the Event input on the picPET. Then the data collection program grabs the time, flaps a modem control signal, grabs the time again, then grabs the text from the picPET and logs everything. -- These are my opinions. I hate spam. ___ 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.
