[time-nuts] O/T: Help requested
Dear All, I would like to buy a second-hand Radio Astronomy book, only available in the USA, before the book becomes unobtainable. The author is someone that I had the privilege to know personally and I am very proud of that knowledge. The problem is that the seller doesn't want to send it abroad. Is there someone in this noble list kind enough to go between and re-send the book for me? Being so, please contact me off the list. Thanks in advance. -- Antonio A.S. Magalhaes/CT1TE ___ 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] Electronically Disciplined Mechanical Pendulum
Several years ago (OK, the last millenium) I GPS disciplined a friend of mines 200 year old grandfather clock that she had inherited. I used a solenoid to nudge the pendulum. Surprisingly, it worked quite well the first time. The biggest problem was the pendulum did not swing at a 1Hz rate. I think it was needed like 24 pulses/minute.I later played with using a magnet/electromagnet instead of the solenoid, but it did not seem to work as well. ___ 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] Attila Kinali's Request for inductance information
Long-time lurker here. Attila, you might find the book "Inductance: Loop and Partial" by Clayton Paul to be what you're looking for. IEEE Press / Wiley --Fred > > Message: 14 > Date: Fri, 26 Jun 2015 14:34:15 +0200 > From: Attila Kinali > To: Discussion of precise time and frequency measurement > > Subject: Re: [time-nuts] magnetic electronic components > Message-ID: <20150626143415.202ea02460c2cb4b21294...@kinali.ch> > Content-Type: text/plain; charset=UTF-8 > > Moin! > > Thanks for all the answers and sorry for my late reply. > I tried to at least skim trough the suggestions before. > > I would like to reply in one big mail instead of many small > ones, in order not to clutter the mailinglist too much. > > On Tue, 23 Jun 2015 00:15:29 +0100 > Adrian Godwin wrote: > > > Although it's published by a vendor, this applications manual has a lot of > > useful information. > > > > http://www.we-online.com/web/en/electronic_components/produkte_pb/fachbuecher/Trilogie.php > > Even though, I do not own a copy of The Trilogy, I know of it. > It does a good job of covering the basics. But unfortunately, it > does not contain much about the theoretical background, so does > not help much in understanding how to work around the physical limits > of cores. Other than that, I would recommend this book to every practicioning > electrical engineer. > > On Mon, 22 Jun 2015 18:56:02 -0500 > Bob kb8tq wrote: > > > You have two choices: > > > > 1) Read the physics stuff > > 2) Go back far enough that the divide had not occurred ( <= 1950’s). > > > > Sorry about that …. > > Yes. I came to a similar conclusion. What irks me is, that this is > the conclusion I came to with many topics in electrical engineering. > At some point people decide that it is either too difficult to deal with > or a solved problem and ignore it completely from then on. And if you > are an engineer who tries to actually understand things instead of just > repeating what some senior engineer told you long long ago, then you > run up against walls. :-( > > On Mon, 22 Jun 2015 20:24:14 -0700 > Jim Lux wrote: > > > the best, and probably the only, book is the one by E.C. Snelling. > > http://www.amazon.com/Soft-ferrites-properties-applications-Snelling/dp/0592027902 > > > > 1969 edition is > > https://archive.org/details/SNELLING__SOFT-FERRITES__1969 > > > > and it's not like the properties of magnetic fields have changed. > > Cool! Thanks a lot! I was looking for this, but couldn't find it. > I somehow missed that archive.org had a copy. > > On Tue, 23 Jun 2015 07:25:57 -0400 > Tim Shoppa wrote: > > > Here in the USA, iron powder and ferrite cores of many different materials, > > sizes, and a few shapes are available from Amidon and kitsandparts.com. > > Many useful ferrite cores for multi-turn transformers and chokes, are sold > > as "EMI beads" by Mouser and Newark and other mainline distributors. I > > don't know too much about easy availability in EU. > > Buying cores is not much of a problem. For one there are the distributors > you have mentioned, for another we have companies like Würth here in > Germany and Coilcraft in the US who are no afraid of selling single pieces > (if they dont just regard it as samples). > > BTW: I really like to work with Würth. I know very few components companies > that go so much out of their way to help a struggling engineer to get his > project done. And they never ask about the volume of your project. You need > help, you get help. > > > Thanks for all the replies and suggesttion. And sorry if I don't answer all > of them individually. > > Attila Kinali ___ 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] Cisco Nexus switches and the leap second
All, Thought this might be of interest to the group. It seems Cisco, at this time, is recommending most users turn off NTP some of their higher end (Data center oriented) switches (Nexus series, at least) until after the leap second then re-enable. For example: http://www.cisco.com/web/about/doing_business/leap-second.html (this is entertaining since it doesn’t actually admit there are any issues) http://www.reddit.com/r/networking/comments/325l60/psa_do_a_cisco_leap_second_bug_scrub_before_june/ Here are links to some of the bugs: https://tools.cisco.com/quickview/bug/CSCub38654 https://tools.cisco.com/quickview/bug/CSCua77416 https://tools.cisco.com/quickview/bug/CSCub38654 I found out about this since our network team on campus is doing just this… turning off NTP until after, then turning it back on. I find it pretty amazing that it actually causes the switch to lock up. I guess after things went sideways (a bit) in 2012 they didn’t think it was a big deal to address completely before this year. Anyway, just figured it might be of interest to those on this list that are also involved in data Networking (or just find it interesting). -Ryan Stasel ___ 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] magnetic electronic components
>BTW: I really like to work with Würth. I know very few components companies >that go so much out of their way to help a struggling engineer to get his >project done. And they never ask about the volume of your project. You need >help, you get help. In the US if you live in a area that has a local Allied or similar mega-distrib's office, get to know one of the sales or technical reps in the office. Quite easy to do if you go to a few of the free seminars they always host. Most of the technical guys and gals are very open to helping the little guy. Be honest that your interest is for yourself or your a one man show. On Fri, Jun 26, 2015 at 5:34 AM, Attila Kinali wrote: > Moin! > > Thanks for all the answers and sorry for my late reply. > I tried to at least skim trough the suggestions before. > > I would like to reply in one big mail instead of many small > ones, in order not to clutter the mailinglist too much. > > On Tue, 23 Jun 2015 00:15:29 +0100 > Adrian Godwin wrote: > > > Although it's published by a vendor, this applications manual has a lot > of > > useful information. > > > > > http://www.we-online.com/web/en/electronic_components/produkte_pb/fachbuecher/Trilogie.php > > Even though, I do not own a copy of The Trilogy, I know of it. > It does a good job of covering the basics. But unfortunately, it > does not contain much about the theoretical background, so does > not help much in understanding how to work around the physical limits > of cores. Other than that, I would recommend this book to every > practicioning > electrical engineer. > > On Mon, 22 Jun 2015 18:56:02 -0500 > Bob kb8tq wrote: > > > You have two choices: > > > > 1) Read the physics stuff > > 2) Go back far enough that the divide had not occurred ( <= 1950’s). > > > > Sorry about that …. > > Yes. I came to a similar conclusion. What irks me is, that this is > the conclusion I came to with many topics in electrical engineering. > At some point people decide that it is either too difficult to deal with > or a solved problem and ignore it completely from then on. And if you > are an engineer who tries to actually understand things instead of just > repeating what some senior engineer told you long long ago, then you > run up against walls. :-( > > On Mon, 22 Jun 2015 20:24:14 -0700 > Jim Lux wrote: > > > the best, and probably the only, book is the one by E.C. Snelling. > > > http://www.amazon.com/Soft-ferrites-properties-applications-Snelling/dp/0592027902 > > > > 1969 edition is > > https://archive.org/details/SNELLING__SOFT-FERRITES__1969 > > > > and it's not like the properties of magnetic fields have changed. > > Cool! Thanks a lot! I was looking for this, but couldn't find it. > I somehow missed that archive.org had a copy. > > On Tue, 23 Jun 2015 07:25:57 -0400 > Tim Shoppa wrote: > > > Here in the USA, iron powder and ferrite cores of many different > materials, > > sizes, and a few shapes are available from Amidon and kitsandparts.com. > > Many useful ferrite cores for multi-turn transformers and chokes, are > sold > > as "EMI beads" by Mouser and Newark and other mainline distributors. I > > don't know too much about easy availability in EU. > > Buying cores is not much of a problem. For one there are the distributors > you have mentioned, for another we have companies like Würth here in > Germany and Coilcraft in the US who are no afraid of selling single pieces > (if they dont just regard it as samples). > > BTW: I really like to work with Würth. I know very few components companies > that go so much out of their way to help a struggling engineer to get his > project done. And they never ask about the volume of your project. You need > help, you get help. > > > Thanks for all the replies and suggesttion. And sorry if I don't answer all > of them individually. > > Attila Kinali > -- > It is upon moral qualities that a society is ultimately founded. All > the prosperity and technological sophistication in the world is of no > use without that foundation. > -- Miss Matheson, The Diamond Age, Neil Stephenson > ___ > 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] Jackson labs fury gpsdo with docxo for sale
On Thu, Jun 25, 2015 at 5:25 PM, Rhys D wrote: > According to the brochure, they are only $750 new. > > Or am I missing something here? > > A search should answer this but I'll (apologetically) inject -- time-nuts price in 2013, quant. 1: Fury desktop, double oven OCXO $1,759.00 ___ 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] PCI-E Serial Card For Windows NTP?
> However, it has been noted that the Raspberry Pi has some limitations for > this purpose, not the least of which is having a USB connected ethernet port. Windows 7 in particular offers it's own set of trouble. Based on my experiences with both platforms, it will be harder to extract consistent and predictable NTP performance from Win7 than Raspberry Pi. Many others have suggested that you experiment with BeagleBone Black; is there a particular reason that you prefer to take the long route? The out-of-box performance is already very good, and there is plenty of remaining challenge and accuracy available from engaging the hardware timers, using a RTOS, and even replacing the main oscillator. I believe the ethernet controller is even capable of PTP should you wish to go beyond NTP (never tried it myself). John On Thu, Jun 25, 2015 at 8:55 PM, Brian M wrote: > Trying not to go offtopic. If there are specific lists for this type of > nuttery, contact me off list - would love to learn and discuss more. > That said - if you're going to test the impact on latency for interrupt > coalescing, I'd suggest using sockperf ping pong test: > https://github.com/mellanox/sockperf > Should reveal a bit more than a simple icmp ping test can. Use the --pps > flag to test a variety of packet rates. Should help show the effect of > coalescing. > - Brian > > On Thu, Jun 25, 2015 at 13:40 Hal Murray wrote: > >> >> I know next-to-nothing about Windows. >> >> Serial ports are pretty standard. I'd get the cheapest card. I'd probably >> pay a bit more for a second port. It might be handy tomorrow. >> >> One difference between chips is the depth of the FIFO. >> >> PCI card now come in two heights. Make sure you get the right one. The >> short ones don't have room for a second connector. (Some cards come with >> two >> face plates. You can swap in/out the other one if you can use a >> screwdriver.) >> >> >> The other thing to keep an eye on is interrupts from the Gigabit ethernet. >> With a lot of short packets, you can get in trouble spending all your CPU >> time in the interrupt handler. Some hardware is setup to batch interrupts. >> The idea is to delay an interrupt for a while in hopes that more packets >> will >> arrive and get processed as a batch. You may want to turn that off. It's >> a >> tradeoff between latency and CPU usage. You may be able to measure it with >> something like ping. >> >> >> >> -- >> 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. ___ 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] magnetic electronic components
Moin! Thanks for all the answers and sorry for my late reply. I tried to at least skim trough the suggestions before. I would like to reply in one big mail instead of many small ones, in order not to clutter the mailinglist too much. On Tue, 23 Jun 2015 00:15:29 +0100 Adrian Godwin wrote: > Although it's published by a vendor, this applications manual has a lot of > useful information. > > http://www.we-online.com/web/en/electronic_components/produkte_pb/fachbuecher/Trilogie.php Even though, I do not own a copy of The Trilogy, I know of it. It does a good job of covering the basics. But unfortunately, it does not contain much about the theoretical background, so does not help much in understanding how to work around the physical limits of cores. Other than that, I would recommend this book to every practicioning electrical engineer. On Mon, 22 Jun 2015 18:56:02 -0500 Bob kb8tq wrote: > You have two choices: > > 1) Read the physics stuff > 2) Go back far enough that the divide had not occurred ( <= 1950’s). > > Sorry about that …. Yes. I came to a similar conclusion. What irks me is, that this is the conclusion I came to with many topics in electrical engineering. At some point people decide that it is either too difficult to deal with or a solved problem and ignore it completely from then on. And if you are an engineer who tries to actually understand things instead of just repeating what some senior engineer told you long long ago, then you run up against walls. :-( On Mon, 22 Jun 2015 20:24:14 -0700 Jim Lux wrote: > the best, and probably the only, book is the one by E.C. Snelling. > http://www.amazon.com/Soft-ferrites-properties-applications-Snelling/dp/0592027902 > > 1969 edition is > https://archive.org/details/SNELLING__SOFT-FERRITES__1969 > > and it's not like the properties of magnetic fields have changed. Cool! Thanks a lot! I was looking for this, but couldn't find it. I somehow missed that archive.org had a copy. On Tue, 23 Jun 2015 07:25:57 -0400 Tim Shoppa wrote: > Here in the USA, iron powder and ferrite cores of many different materials, > sizes, and a few shapes are available from Amidon and kitsandparts.com. > Many useful ferrite cores for multi-turn transformers and chokes, are sold > as "EMI beads" by Mouser and Newark and other mainline distributors. I > don't know too much about easy availability in EU. Buying cores is not much of a problem. For one there are the distributors you have mentioned, for another we have companies like Würth here in Germany and Coilcraft in the US who are no afraid of selling single pieces (if they dont just regard it as samples). BTW: I really like to work with Würth. I know very few components companies that go so much out of their way to help a struggling engineer to get his project done. And they never ask about the volume of your project. You need help, you get help. Thanks for all the replies and suggesttion. And sorry if I don't answer all of them individually. Attila Kinali -- It is upon moral qualities that a society is ultimately founded. All the prosperity and technological sophistication in the world is of no use without that foundation. -- Miss Matheson, The Diamond Age, Neil Stephenson ___ 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] Electronically Disciplined Mechanical Pendulum
Bert, Thank you for posting your project info! One of my hobbies is collecting and repairing clocks. For several years I've been thinking of making an add-on device to discipline pendulum clocks. I've been using PIC based circuits to provide pendulum impulse. I've not tried to discipline the rate as you've done. You said that your circuit had problems locking the pendulum rate when you used an aluminum pendulum rod. Now that you have an oak rod I was wondering if your pendulum would remain locked when you turned off the temperature control. With an oak rod and no temperature control your pendulum would have temperature stability similar to common pendulum clocks. If your circuit can maintain lock without temperature control that tells me that it should be possible to discipline a common pendulum clock using this method. I'm sorry, I'm asking you to perform another test on your pendulum. Can it maintain lock with normal temperature changes? Let it run for a few days with the heater off and see what happens. Also, You may want to try something other than a hard drive bearing to suspend your pendulum. Since your circuit is line powered this is not a big problem. I've performed tests with several pendulum suspension methods including the head support arm bearing from a hard drive. The hard drive bearing performed poorly. You'll need less power to keep it swinging with other suspension methods. Using the hard drive bearing, my pendulum had a Q factor of about 2,000. Using various traditional clock pendulum suspension springs the Q ranged from 5,000 to 13,000. With a crossed wire suspension the Q was 28,000. Finally, below is a link to some pictures of my clock project. I want this to be a traditional style master clock. Something that my wife won't complain about if I put it in the living room! I don't have the skills or machine tools needed to build a completely mechanical master clock. Electromagnetic impulse is my current choice. http://mesterhome.com/clock/picpend/index.html -- Luke Mester http://mesterhome.com/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Jackson labs fury gpsdo with docxo for sale
The double oven? Sent from mobile > On Jun 25, 2015, at 4:25 PM, Rhys D wrote: > > According to the brochure, they are only $750 new. > > Or am I missing something here? > > R > >> On 26 June 2015 at 03:30, Mark Spencer wrote: >> >> Hi I'm wondering if there is any interest in my Jackson labs fury (desktop >> version) with the docxo option. I purchased it new from Jackson Labs in >> 2012. >> >> It has sat on a shelf powered up for almost the entire time I have owned >> it. I've been very happy with the unit but I haven't made much use of it >> over the last year and don't foresee any future need for it. >> >> I'm not in a huge hurry to sell it but I would be looking for 1,250 USD >> plus insured shipping from Canada (also the buyer would need to pay any >> taxes or duties that are payable by the buyer.) I would include the power >> supply it shipped with from Jackson labs. >> >> I'm also looking at selling it via some other channels as well so it may >> be gone soon. >> >> Please contact me off list if you are interested in pursuing this. I'm >> happy to send photos and provide more details to an interested party. >> >> Thanks >> Mark Spencer >> m...@alignedsolutions.com >> >> ___ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. > ___ > time-nuts 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] Jackson labs fury gpsdo with docxo for sale
Hi: According to the brochure that price is for 20 plus pieces (presumably for the oem pcb module non docxo option variant although it does not say so.) Best regards Mark S Sent from my iPhone > On Jun 25, 2015, at 2:25 PM, Rhys D wrote: > > According to the brochure, they are only $750 new. > > Or am I missing something here? > > R > >> On 26 June 2015 at 03:30, Mark Spencer wrote: >> >> Hi I'm wondering if there is any interest in my Jackson labs fury (desktop >> version) with the docxo option. I purchased it new from Jackson Labs in >> 2012. >> >> It has sat on a shelf powered up for almost the entire time I have owned >> it. I've been very happy with the unit but I haven't made much use of it >> over the last year and don't foresee any future need for it. >> >> I'm not in a huge hurry to sell it but I would be looking for 1,250 USD >> plus insured shipping from Canada (also the buyer would need to pay any >> taxes or duties that are payable by the buyer.) I would include the power >> supply it shipped with from Jackson labs. >> >> I'm also looking at selling it via some other channels as well so it may >> be gone soon. >> >> Please contact me off list if you are interested in pursuing this. I'm >> happy to send photos and provide more details to an interested party. >> >> Thanks >> Mark Spencer >> m...@alignedsolutions.com >> >> ___ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. > ___ > time-nuts 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.
