Re: [time-nuts] National Standards labs worldwide - specifically Australia
Hi David Standards Australia performs a somewhat different function in that it does not maintain reference standards or do testing but rather it produces written standards such as for construction of buildings, electrical wiring and food standards. Standards Australia is certainly authoritative in that it is partly supported by a Government grant and has a range of specialist committees with Industry and Government representation and the written standards it produces are often referred to in Federal and State Government legislation and then have the authority of Law. Reference standards are maintained by a range of other bodies but the prime one is the National Measurement Institute. http://www.measurement.gov.au/Pages/default.aspx In terms of the sort of measurement such as reflection of a 50 ohm load this work is normally done by NATA (National Association of Testing Authorities) accredited laboratories. http://www.nata.com.au/nata/ 73 Rex VK7MO ___ 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] Dephasing WWVB
John Reed wrote : By the way, my 5 section synchronous filter is an LC with op-amps between each stage to bring the gain up for the squaring chip. It has a 2 KHz -6 dB bandwidth at 60 KHz. John, have you thought of using a single 60.0 kHz crystal as a bandpass filter? I can't remember which receiver it was, but I think one of the old commercial WWVB receivers used a crystal as the tuning element. ... Martin VE3OAT ___ 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] Dephasing WWVB
Many of the old receivers use them spectracoms come to mind. They are big units and +- 40 Hz BW and I am totally unaware that they can be found today. That also goes for nice transformers and inductors to build higher Q circuits. I built a opamp chain and it worked well but those crazy amps do draw power. I like the ua consumption level. But thats a personnel preference. I used the 60 KHz watch Xtals and its in the schematics of the WWVB rcvr I released to time-nuts a year ago. These little crystals are interesting to work with and available from China 25 xtals for a few $ at the pay site. I purchased 2 packs so that I could sift through them. The trick is to very very lightly load them. I could learn much more about them actually. They seem useful overall. The first re-modulator used them directly as the 60 KHz source. I stepped up to the 15.360 MHz osc only because I believed they were not accurate enough and that turned out not to be the case as I found. The other comment to note is that these xtals cause an actual signal gap at the phase transition. Because at that point the signal is actually 2 X 60 Khz. The crystal gaps for at least 8 cycles from what I have seen. Regards Paul WB8TSL On Sun, Jun 29, 2014 at 6:39 PM, Martin VE3OAT ve3...@storm.ca wrote: John Reed wrote : By the way, my 5 section synchronous filter is an LC with op-amps between each stage to bring the gain up for the squaring chip. It has a 2 KHz -6 dB bandwidth at 60 KHz. John, have you thought of using a single 60.0 kHz crystal as a bandpass filter? I can't remember which receiver it was, but I think one of the old commercial WWVB receivers used a crystal as the tuning element. ... Martin VE3OAT ___ 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] Dephasing WWVB
First on the Schmidt trigger - The problem is that at the start of each bit that WWVB transmits the squared 60 KHz signal is essentially dead and the trigger must pick a new starting point. This point seems to be random and can apparently end up as a positive or negative, so you end up with phase changes of 180 after the flip flop. No trigger can fix this. The system has to have some memory of the phase and this is why the Costas loop works. I thought about getting rid of the 100 KHz front end filter in the Tracor and seeing if I could modify it by squaring the LO signal. This isn't straightforward either. The Tracor has a complex method of generating the IF signal. I wasn't aware that 60 KHz crystals are available. I would have used these instead of the LC filters. I had some old telephone loading ferrite toroid coils, so most of the hardware was available. Thanks for all the comments on this. At least I understand the problem now, and why the solution will take some work. John -Original Message- From: paul swed Sent: Monday, June 30, 2014 9:49 AM To: Martin VE3OAT ; Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Dephasing WWVB Many of the old receivers use them spectracoms come to mind. They are big units and +- 40 Hz BW and I am totally unaware that they can be found today. That also goes for nice transformers and inductors to build higher Q circuits. I built a opamp chain and it worked well but those crazy amps do draw power. I like the ua consumption level. But thats a personnel preference. I used the 60 KHz watch Xtals and its in the schematics of the WWVB rcvr I released to time-nuts a year ago. These little crystals are interesting to work with and available from China 25 xtals for a few $ at the pay site. I purchased 2 packs so that I could sift through them. The trick is to very very lightly load them. I could learn much more about them actually. They seem useful overall. The first re-modulator used them directly as the 60 KHz source. I stepped up to the 15.360 MHz osc only because I believed they were not accurate enough and that turned out not to be the case as I found. The other comment to note is that these xtals cause an actual signal gap at the phase transition. Because at that point the signal is actually 2 X 60 Khz. The crystal gaps for at least 8 cycles from what I have seen. Regards Paul WB8TSL On Sun, Jun 29, 2014 at 6:39 PM, Martin VE3OAT ve3...@storm.ca wrote: John Reed wrote : By the way, my 5 section synchronous filter is an LC with op-amps between each stage to bring the gain up for the squaring chip. It has a 2 KHz -6 dB bandwidth at 60 KHz. John, have you thought of using a single 60.0 kHz crystal as a bandpass filter? I can't remember which receiver it was, but I think one of the old commercial WWVB receivers used a crystal as the tuning element. ... Martin VE3OAT ___ 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] Bolivian Congress building clock now runs counter-clockwise
The clock face has also been redrawn so the rate of time passage is still positive: http://www.bbc.com/news/world-latin-america-28013157 I've seen one article that argues that this is more natural in the southern hemisphere, since the shadow on a sundial rotates CCW there. - Dave ___ 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] Dephasing WWVB
Yes indeed I have 2 X 599s also and the IF is complicated and if you don't have the magical 60 KHz mod (I don't) you have to hack a solution. That I did. Essentially double the vco and div by 2. While feeding the vco to the mixer. Hey it worked most of the time and on a solid test signal always worked and I mean for weeks. The 60 KHz xtals existed and still may. Fun to tinker with and cheap. In fact because if the IF scheme of the 599 thats why I went to an external solution. You can hack each rcvr internally to succeed. But thats hacking. An external approach allows all of them to work. The 117s 207 spectracoms... Hence the d-psk-r/costas loop soluyion released a year ago. But its semi digital and analog and I have to say I never really figured out what the magical VCO filter needed to be. Though I experimented. It works. But its a guess. Regards Paul On Mon, Jun 30, 2014 at 1:00 PM, John Reed ka5...@sbcglobal.net wrote: First on the Schmidt trigger - The problem is that at the start of each bit that WWVB transmits the squared 60 KHz signal is essentially dead and the trigger must pick a new starting point. This point seems to be random and can apparently end up as a positive or negative, so you end up with phase changes of 180 after the flip flop. No trigger can fix this. The system has to have some memory of the phase and this is why the Costas loop works. I thought about getting rid of the 100 KHz front end filter in the Tracor and seeing if I could modify it by squaring the LO signal. This isn't straightforward either. The Tracor has a complex method of generating the IF signal. I wasn't aware that 60 KHz crystals are available. I would have used these instead of the LC filters. I had some old telephone loading ferrite toroid coils, so most of the hardware was available. Thanks for all the comments on this. At least I understand the problem now, and why the solution will take some work. John -Original Message- From: paul swed Sent: Monday, June 30, 2014 9:49 AM To: Martin VE3OAT ; Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Dephasing WWVB Many of the old receivers use them spectracoms come to mind. They are big units and +- 40 Hz BW and I am totally unaware that they can be found today. That also goes for nice transformers and inductors to build higher Q circuits. I built a opamp chain and it worked well but those crazy amps do draw power. I like the ua consumption level. But thats a personnel preference. I used the 60 KHz watch Xtals and its in the schematics of the WWVB rcvr I released to time-nuts a year ago. These little crystals are interesting to work with and available from China 25 xtals for a few $ at the pay site. I purchased 2 packs so that I could sift through them. The trick is to very very lightly load them. I could learn much more about them actually. They seem useful overall. The first re-modulator used them directly as the 60 KHz source. I stepped up to the 15.360 MHz osc only because I believed they were not accurate enough and that turned out not to be the case as I found. The other comment to note is that these xtals cause an actual signal gap at the phase transition. Because at that point the signal is actually 2 X 60 Khz. The crystal gaps for at least 8 cycles from what I have seen. Regards Paul WB8TSL On Sun, Jun 29, 2014 at 6:39 PM, Martin VE3OAT ve3...@storm.ca wrote: John Reed wrote : By the way, my 5 section synchronous filter is an LC with op-amps between each stage to bring the gain up for the squaring chip. It has a 2 KHz -6 dB bandwidth at 60 KHz. John, have you thought of using a single 60.0 kHz crystal as a bandpass filter? I can't remember which receiver it was, but I think one of the old commercial WWVB receivers used a crystal as the tuning element. ... Martin VE3OAT ___ 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] Opinions on OpenNTPD
I think OpenNTPD goes not try to be a stratum 1 server. It is not something you would connect a hardware reference clock to. Look at the man page for the .conf file. On Thu, Jun 26, 2014 at 11:14 PM, Matthew Martin dr.g...@gmail.com wrote: Greetings to the group! I just obtained a Rev C Beagleboard Black this week, and the standard distribution does not include ntpd. When I check for available ntpd related packages using the aptitude command, it offers OpenBSD's openntpd as the one available ntpd package. A little bit of research on the OpenNTPD project suggests to me that it is a lightweight ntpd implementation. They even suggest that if you are looking for the ultimate accuracy you may not want to use OpenNTPD. Has anyone here actually used OpenNTPD, and perhaps made a comparison with a more standard ntpd package? I get the feeling that I would be better off with a standard ntpd. Does OpenNTPD even support PPS or the variety of clock source drivers that standard ntpd supports? Thanks to the group for your help. Matt ___ 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] Sad news Ulrich Bangert
Dear group, please let me express my thanks for all your condolences. I collected them all and will pass them to Ulrichs relatives. I am quite sure they will be surprised and pleased about the number of people who sent a message. There was the question what will happen with Ulrichs software tools. They definitively will not fade way. The web site will stay active, probably with just the download section active. I knew Ulrich for some 25 years. Besides being friends, we also did quite a lot of professional collaboration. From this I know his working style. I do have the source code and am familiar with the development tools he used. So basically I am able to maintain and develop the software further. I use the term basically because Ulrichs special knowledge in accurate timing and oscillators was at least one, if not two, orders of magnitude better than mine. Ulrich never disclosed source code and I will obey his desire. Best regards, Hartmut DL1YDD On Fri, Jun 20, 2014 at 03:12:36PM -0700, Tom Van Baak wrote: Hi Hartmut, Thanks for letting us know. Ulrich has been on this mailing list since the early days. He is one of several with his own web site (www.ulrich-bangert.de) and freely shared his designs, articles, and software tools with the world. He was a quality contributor to the list, and many of us also have lots of private emails from him over the years. As Said already mentioned, please pass along condolences to his loved ones, on behalf of the group. Thanks, /tvb - Original Message - From: Hartmut Paesler timen...@paesler.de To: time-nuts@febo.com Sent: Friday, June 20, 2014 1:52 PM Subject: [time-nuts] Sad news Ulrich Bangert Dear group, unfortunately I have to deliver the sad news that Ulrich Bangert, DF6JB passed away on 11/06, aged 59. Best regards, Hartmut DL1YDD ___ 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] Sad news Ulrich Bangert
Hartmut that is indeed a friend that can keep a persons knowledge going and had been entrusted with the details. Good luck to you and thank you. Regards Paul WB8TSL On Mon, Jun 30, 2014 at 6:23 PM, Hartmut Paesler timen...@paesler.de wrote: Dear group, please let me express my thanks for all your condolences. I collected them all and will pass them to Ulrichs relatives. I am quite sure they will be surprised and pleased about the number of people who sent a message. There was the question what will happen with Ulrichs software tools. They definitively will not fade way. The web site will stay active, probably with just the download section active. I knew Ulrich for some 25 years. Besides being friends, we also did quite a lot of professional collaboration. From this I know his working style. I do have the source code and am familiar with the development tools he used. So basically I am able to maintain and develop the software further. I use the term basically because Ulrichs special knowledge in accurate timing and oscillators was at least one, if not two, orders of magnitude better than mine. Ulrich never disclosed source code and I will obey his desire. Best regards, Hartmut DL1YDD On Fri, Jun 20, 2014 at 03:12:36PM -0700, Tom Van Baak wrote: Hi Hartmut, Thanks for letting us know. Ulrich has been on this mailing list since the early days. He is one of several with his own web site ( www.ulrich-bangert.de) and freely shared his designs, articles, and software tools with the world. He was a quality contributor to the list, and many of us also have lots of private emails from him over the years. As Said already mentioned, please pass along condolences to his loved ones, on behalf of the group. Thanks, /tvb - Original Message - From: Hartmut Paesler timen...@paesler.de To: time-nuts@febo.com Sent: Friday, June 20, 2014 1:52 PM Subject: [time-nuts] Sad news Ulrich Bangert Dear group, unfortunately I have to deliver the sad news that Ulrich Bangert, DF6JB passed away on 11/06, aged 59. Best regards, Hartmut DL1YDD ___ 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] Opinions on OpenNTPD
On 2014-06-27 00:14, Matthew Martin wrote: Greetings to the group! I just obtained a Rev C Beagleboard Black this week, and the standard distribution does not include ntpd. When I check for available ntpd related packages using the aptitude command, it offers OpenBSD's openntpd as the one available ntpd package. A little bit of research on the OpenNTPD project suggests to me that it is a lightweight ntpd implementation. They even suggest that if you are looking for the ultimate accuracy you may not want to use OpenNTPD. Has anyone here actually used OpenNTPD, and perhaps made a comparison with a more standard ntpd package? I get the feeling that I would be better off with a standard ntpd. Does OpenNTPD even support PPS or the variety of clock source drivers that standard ntpd supports? Reply by Harlan Stenn to a message on NTP list: e1w2tov-0002qs...@stenn.ntp.org last I checked openntpd was actually an SNTP implementation, not an NTP implementation. H and I saw some comments talking about adding support for leap seconds, so I wouldn't expect it to support any of the algorithms, only the protocol. -- Take care. Thanks, Brian Inglis ___ 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] Opinions on OpenNTPD
The last time I looked openntp was really an SNTP implementation. If you are running it on a leaf node it might be fine for you. -- Harlan Stenn st...@ntp.org http://networktimefoundation.org - be a member! ___ 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] Fwd from NANOG: Erroneous Leap Second Introduced at 2014-06-30 23:59:59 UTC
Begin forwarded message: From: Tim Heckman t...@heckman.io Date: June 30, 2014 at 17:33:52 PDT To: na...@nanog.org Subject: Erroneous Leap Second Introduced at 2014-06-30 23:59:59 UTC Hey Everyone, I just was alerted to one of the systems I managed having a time skew greater than 100ms from NTP sources. Upon further investigation it seemed that the time was off by almost exactly 1 second. Looking back over our NTP monitoring, it would appear that this system had a large time adjust at approximately 00:00 UTC: - http://puu.sh/9Rs6O/a514ad7c97.png (times are in Pacific in these graphs, sorry about that) A few of our systems did alert early this morning, indicating they were going to be receiving a leap second today. However, I was unable to determine the exact cause for NTP believing a leap second should be added. And after some time a few of the systems were no longer indicating that a leap second would be introduced. This specific system is hosted in AWS US-WEST-2C and uses the 0.amazon.pool.ntp.org pool. Has anyone else seen any erroneous leap seconds being added to their system? Cheers! -Tim Heckman ___ 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.
