Re: [time-nuts] WWVB Simulator
This could be done with a LOT fewer chips. Two ways to go 1) All you need is a phase inverter controlled by a one bit signal and an attenuator also controlled by a one bit signal and a small micro controller. the small uP provides the two control signals. It maybe gets time from a 1PPs 2) A faster computer could do direct synthesis of the 60KHz waveform You write 180K samples to a DAC per secondOne of the $10 ARM SBCs will work. You would need to apply a good 60KHz low pass filter On Mon, Jan 2, 2017 at 1:18 PM, M. Simon via time-nuts wrote: > I have come up with a ridiculously simple WWVB simulator that simulates both > the AM modulation and the BPSK modulation. > > A simple explanation and a link to the core schematic can be found here: > http://spacetimepro.blogspot.com/2017/01/wwvb-simulator.html > I'm working on fleshing out the design and producing a PCB. Any comments or > suggestions before I complete the design are welcome. I will try to > incorporate useful suggestions in the final design. > > Note: I have looked all over the 'net for a similar design or any thing > hinting at it. I found nothing. Once you see the design it becomes obvious. > > What clarified it for me is that I looked at the last diagram in this file > http://www.wparc.us/presentations/SDR-2-19-2013/Tayloe_mixer_x3a.pdf and > then plotted out the digital version of what the one cycle of the carrier > would look like given that the signal is just made up of ones and zeros. > The final design (as far as I have gone) incorporates a synchronizing latch > so the signals only change at the "zero" of the modulator. > > Simon > Engineering is the art of making what you want from what you can get at a > profit. > I like Polywell Fusion. > ___ > 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] WWVB Simulator
time-nuts@febo.com said: > I have come up with a ridiculously simple WWVB simulator that simulates both > the AM modulation and the BPSK modulation. Did you consider software? Is the audio on a Raspberry Pi fast enough? I haven't looked at any details, but you can get ARM CPUs for ballpark of $5 on eBay. There is a good chance that one of their IO devices will let you send raw bits via a DMA channel. -- 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] 5372A A7 CPU board
I took a lot ok through the service manual, but didn't see the A7 schematic. Is it someplace non obvious? Thanks! > On Jan 2, 2017, at 23:00, John Allen wrote: > > Hi Bob - I have a OCR'd service manual with schematics. There is also one on > the KO4BB site > http://www.ko4bb.com/getsimple/index.php?id=manuals > > I can post mine if that one isn't sufficient. > > Regards, John K1AE, Bolton, MA > > -Original Message- > From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob Bownes > Sent: Monday, January 02, 2017 8:13 PM > To: Discussion of precise time and frequency measurement > Subject: [time-nuts] 5372A A7 CPU board > > > I have the CPU board 05372-6007 out of my 5372A this evening to replace the > battery. While looking at it, I see jumpers for 64/256K and 512k/2M. > > I suspect the 64/256 is for the RAM as it is located next to the (non > socketed) RAM. > > Does anyone have a schematic or listing of what all the jumpers are for? > > Thanks! > Bob > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > > --- > This email has been checked for viruses by Avast antivirus software. > https://www.avast.com/antivirus > > ___ > 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] 5372A A7 CPU board
I once saw a mention that the only difference between a 5372 and 5373 was the firmware. A guy sent me some 5373A rom dumps and I tried them in a 5372... no joy. It could be the PALs on the CPU board are different... or the rumor was incorrect. ___ 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] 5372A A7 CPU board
Hi Bob - I have a OCR'd service manual with schematics. There is also one on the KO4BB site http://www.ko4bb.com/getsimple/index.php?id=manuals I can post mine if that one isn't sufficient. Regards, John K1AE, Bolton, MA -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob Bownes Sent: Monday, January 02, 2017 8:13 PM To: Discussion of precise time and frequency measurement Subject: [time-nuts] 5372A A7 CPU board I have the CPU board 05372-6007 out of my 5372A this evening to replace the battery. While looking at it, I see jumpers for 64/256K and 512k/2M. I suspect the 64/256 is for the RAM as it is located next to the (non socketed) RAM. Does anyone have a schematic or listing of what all the jumpers are for? Thanks! Bob ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus ___ 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] TrueTime/Symmetricon XL-AK date reset failure
I have had an XL-DC at work since about 1997, serving as a reference
clock for an NTP stratum 1 server. My memory is getting fuzzy, but at
some point (after I called and asked) Truetime mailed me at no cost a
new ROM of some kind and a tool to cahnge it to deal with the W1K bug.
I think that just changed the default assumption ("time could not be
before X") to a later date. Since then, it has been mostly ok, but
occasionally troubled. Manual date entry allowed me to have it continue
to track. It's on a UPS, so it doesn't see power interruptions, and at
this point has probably been on continuously for ~7 years.
I have not been in the office for a while. I'll follow up privately if
it's ok, or on-list if it's troubleed.
___
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Re: [time-nuts] WWVB Simulator
Fwiw, an xor gate would make a simple bpsk modulator, carrier input A modulation B, B is low A is buffered, when B is high, carrier is inverted (180 degree phase shift). On Mon, Jan 2, 2017 at 7:20 PM David wrote: > I see generally how it should work but did not draw out a truth table. > > > > Why use the 74CB3T3253 instead of a low voltage 4052 variant? > > > > It think you could buffer just the two references and save two > > operational amplifiers and 2 or 4 capacitors. > > > > On Mon, 2 Jan 2017 21:18:12 + (UTC), you wrote: > > > > >I have come up with a ridiculously simple WWVB simulator that simulates > both the AM modulation and the BPSK modulation. > > > > > >A simple explanation and a link to the core schematic can be found here: > http://spacetimepro.blogspot.com/2017/01/wwvb-simulator.html > > >I'm working on fleshing out the design and producing a PCB. Any comments > or suggestions before I complete the design are welcome. I will try to > incorporate useful suggestions in the final design. > > > > > >Note: I have looked all over the 'net for a similar design or any thing > hinting at it. I found nothing. Once you see the design it becomes obvious. > > > > > >What clarified it for me is that I looked at the last diagram in this > file http://www.wparc.us/presentations/SDR-2-19-2013/Tayloe_mixer_x3a.pdf > and then plotted out the digital version of what the one cycle of the > carrier would look like given that the signal is just made up of ones and > zeros. > > >The final design (as far as I have gone) incorporates a synchronizing > latch so the signals only change at the "zero" of the modulator. > > > > > >Simon > > ___ > > 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] 5372A A7 CPU board
I have the CPU board 05372-6007 out of my 5372A this evening to replace the battery. While looking at it, I see jumpers for 64/256K and 512k/2M. I suspect the 64/256 is for the RAM as it is located next to the (non socketed) RAM. Does anyone have a schematic or listing of what all the jumpers are for? Thanks! Bob ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] WWVB Simulator
I see generally how it should work but did not draw out a truth table. Why use the 74CB3T3253 instead of a low voltage 4052 variant? It think you could buffer just the two references and save two operational amplifiers and 2 or 4 capacitors. On Mon, 2 Jan 2017 21:18:12 + (UTC), you wrote: >I have come up with a ridiculously simple WWVB simulator that simulates both >the AM modulation and the BPSK modulation. > >A simple explanation and a link to the core schematic can be found here: >http://spacetimepro.blogspot.com/2017/01/wwvb-simulator.html >I'm working on fleshing out the design and producing a PCB. Any comments or >suggestions before I complete the design are welcome. I will try to >incorporate useful suggestions in the final design. > >Note: I have looked all over the 'net for a similar design or any thing >hinting at it. I found nothing. Once you see the design it becomes obvious. > >What clarified it for me is that I looked at the last diagram in this file >http://www.wparc.us/presentations/SDR-2-19-2013/Tayloe_mixer_x3a.pdf and then >plotted out the digital version of what the one cycle of the carrier would >look like given that the signal is just made up of ones and zeros. >The final design (as far as I have gone) incorporates a synchronizing latch so >the signals only change at the "zero" of the modulator. > >Simon ___ 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] TrueTime/Symmetricon XL-AK date reset failure
Hi again Joe, Yesterday was 2 Jan. Which was GPS week:day 1930:2. Walk back 1024 weeks and we are in 906:2. Monday in GPS week 906 was May 19th 1997. And that was also the 139th day in 1997. And I think we can confirm the cause of your problem. How to fix it... the GPS receiver module beeing 20+ years old is unlikely to have a firmware update. But try to identify the model and maybe there is a more modern receiver module that works in your box. Another option could be modifying the XL-AK box firmware to add 1024 weeks to the date. The good thing is that its only the date that is computed wrońg. Position and time-of-day, 1pps etc are all working as good as before. -- Björn > On 1/1/2016, I noticed that the day > counter display did not automatically reset to zero, and start over. The > day > counter display continued increasing incrementally, until 139 days ago, it > finally reset itself to zero and started incrementally increasing again > from > [day] 1. Which means that the day-of-the-year counter function currently > reads "139," when it should read "2." The time display has always remained > accurate. I had hoped the day counter issue would resolve itself at > midnight > on 1/1/2017; but nothing changed. > > > > I know that the TrueTime/Symmetricon XL-AK and XL-DC GPS receivers are > popular, and now that I have discovered this forum; I would like to > solicit > feedback as to what the root of the problem is and how to remedy it, from > anyone on the forum having personal experience with this line of GPS > receivers. Ideas??? > > > > Thanks de Joe-W6VI > > > > > > ___ > 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-5650A option 58 tuning word for 10 MHz output
and if you glue a piece of non-magnetic material -- which could hold that connector -- it could be even some plastic, to the surface of the mu-metal , you do not need to worry about disturbing the magnetic conditions 73 KJ6UHN Alex On 1/2/2017 3:44 PM, Attila Kinali wrote: On Tue, 03 Jan 2017 11:02:54 +1300 Bruce Griffiths wrote: Maybe a waterjet cutter would imapct less on the shielding properties of tthe mumetal? I doubt it. mu-metal is pretty sensitive to vibration as well and a waterjet creates plenty of that. But anealing mu-metal is pretty simple, if one has enough space to build a furnace in the backyard. All you have to do is find a wall material that can withstand the 1000-1500°C annealing temperature and which can be flooded with hydrogen is enough. Flooding the furnace with hydrogen is not dangerous, as long as the interior is completely flooded (no oxygen) and the hydrogen leaks out at well controlled points, where it can burn off. There are descriptions how to do that out there. The only problem is that you need enough space around the furnace for the hydrogen flames to not cause any trouble. Being outside also helps to prevent hydrogen build-ups on the ceiling while initially flooding the furnace or shuting it off. 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.
Re: [time-nuts] FE-5650A option 58 tuning word for 10 MHz output
On Tue, 03 Jan 2017 11:02:54 +1300 Bruce Griffiths wrote: > Maybe a waterjet cutter would imapct less on the shielding properties of > tthe mumetal? I doubt it. mu-metal is pretty sensitive to vibration as well and a waterjet creates plenty of that. But anealing mu-metal is pretty simple, if one has enough space to build a furnace in the backyard. All you have to do is find a wall material that can withstand the 1000-1500°C annealing temperature and which can be flooded with hydrogen is enough. Flooding the furnace with hydrogen is not dangerous, as long as the interior is completely flooded (no oxygen) and the hydrogen leaks out at well controlled points, where it can burn off. There are descriptions how to do that out there. The only problem is that you need enough space around the furnace for the hydrogen flames to not cause any trouble. Being outside also helps to prevent hydrogen build-ups on the ceiling while initially flooding the furnace or shuting it off. 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] TrueTime/Symmetricon XL-AK date reset failure
Hi Joe! The Gps receiver module inside the XL-AK could have been hit by the 1024 week problem. Do the XL box have a display showing date/year? What does that show? -- Björn Sent from my smartphone. Original message From: Joe Pendergrass Date: 02/01/2017 23:29 (GMT+01:00) To: time-nuts@febo.com Subject: [time-nuts] TrueTime/Symmetricon XL-AK date reset failure Hello, all. I am a new member, having discovered this forum a few days ago, whilst doing a Google search looking for current telephone contact information for TrueTime/Symmetricon technical support. For many years I've had a TrueTime/Symmetricon Model XL-AK GPS time & frequency receiver in service here, which drives multiple serially slaved 9-digit LED IRIG-B remote readouts spread around my station. They display the day-of-the-year [counted up from 1/1] and the satellite GMT time. At midnight on each January 1st, the display always updated to reflect the coming of a new calendar year, and the day-of-the-year on the remote displays would reset to "0" [Zero]. On 1/1/2016, I noticed that the day counter display did not automatically reset to zero, and start over. The day counter display continued increasing incrementally, until 139 days ago, it finally reset itself to zero and started incrementally increasing again from [day] 1. Which means that the day-of-the-year counter function currently reads "139," when it should read "2." The time display has always remained accurate. I had hoped the day counter issue would resolve itself at midnight on 1/1/2017; but nothing changed. I know that the TrueTime/Symmetricon XL-AK and XL-DC GPS receivers are popular, and now that I have discovered this forum; I would like to solicit feedback as to what the root of the problem is and how to remedy it, from anyone on the forum having personal experience with this line of GPS receivers. Ideas??? Thanks de Joe-W6VI ___ 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] new year crashes
The number for the fiber is accurate. However, fiber isn't laid straight path. I add at least 40% as a precaution, as if laid on the sides of a square, where the original path is the diagonal. This is however a very conservative measure to real world. However, equipment delays can be much larger, and if you now have buffers they can cause much much higher delays. How well the network is managed controls the additional delay and it's variations. You milage may vary, indeed. These are among the things I need to know after half a bottle of wine. Cheers, Magnus On 01/02/2017 05:58 PM, Mark Spencer wrote: In my prior experience (from approx 5 to 20 years ago) actual wide area net work links delivered over fiber from commercial providers could have latencies of at least several times those figures. I seem to recall efforts were made to lower latencies for applications such as stock trading but I never had any exposure to those connections. Best regards Mark Spencer How can they get a delay that long? Satellite link? Fiber is 5 microseconds per km. So 1000 km is 5 ms. -- 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] FE-5650A option 58 tuning word for 10 MHz output
Hi My biggest concern is that they magnetize the shield as they drill it. It’s a “static” field, but it’s a static *near* field. I doubt that is a good thing …. Bob > On Jan 2, 2017, at 5:53 PM, Bruce Griffiths > wrote: > > One could always wrap the assembly with its impaired mu metal shield in > several layers of flexible magnetic shielding foil to regain the desired > magnetic shielding e.Most such foils can be cut with scissors without > significant effect on their magnetic properties. > Bruce > >On Tuesday, 3 January 2017 11:46 AM, Bob Camp wrote: > > > Hi > > >> On Jan 2, 2017, at 5:02 PM, Bruce Griffiths >> wrote: >> >> >> Maybe a waterjet cutter would imapct less on the shielding properties of >> tthe mumetal? >> > > Maybe …. pretty good bet that the guys modifying these in their living room > aren’t focused on much more than getting them working as fast as they possibly > can. > > Bob > >> Bruce >> >> On Monday, January 02, 2017 12:58:55 PM Bob Camp wrote: >>> Hi >>> On Jan 1, 2017, at 7:31 PM, wb6bnq wrote: Hello Mathias, I think you did not quite understand how the calibration process works with that unit. The factory procedure is to set the pot to minimum and then bring the DDS up to the step that produces the closest > > ___ > 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] TrueTime/Symmetricon XL-AK date reset failure
Hello, all. I am a new member, having discovered this forum a few days ago, whilst doing a Google search looking for current telephone contact information for TrueTime/Symmetricon technical support. For many years I've had a TrueTime/Symmetricon Model XL-AK GPS time & frequency receiver in service here, which drives multiple serially slaved 9-digit LED IRIG-B remote readouts spread around my station. They display the day-of-the-year [counted up from 1/1] and the satellite GMT time. At midnight on each January 1st, the display always updated to reflect the coming of a new calendar year, and the day-of-the-year on the remote displays would reset to "0" [Zero]. On 1/1/2016, I noticed that the day counter display did not automatically reset to zero, and start over. The day counter display continued increasing incrementally, until 139 days ago, it finally reset itself to zero and started incrementally increasing again from [day] 1. Which means that the day-of-the-year counter function currently reads "139," when it should read "2." The time display has always remained accurate. I had hoped the day counter issue would resolve itself at midnight on 1/1/2017; but nothing changed. I know that the TrueTime/Symmetricon XL-AK and XL-DC GPS receivers are popular, and now that I have discovered this forum; I would like to solicit feedback as to what the root of the problem is and how to remedy it, from anyone on the forum having personal experience with this line of GPS receivers. Ideas??? Thanks de Joe-W6VI ___ 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] WWVB Simulator
I have come up with a ridiculously simple WWVB simulator that simulates both the AM modulation and the BPSK modulation. A simple explanation and a link to the core schematic can be found here: http://spacetimepro.blogspot.com/2017/01/wwvb-simulator.html I'm working on fleshing out the design and producing a PCB. Any comments or suggestions before I complete the design are welcome. I will try to incorporate useful suggestions in the final design. Note: I have looked all over the 'net for a similar design or any thing hinting at it. I found nothing. Once you see the design it becomes obvious. What clarified it for me is that I looked at the last diagram in this file http://www.wparc.us/presentations/SDR-2-19-2013/Tayloe_mixer_x3a.pdf and then plotted out the digital version of what the one cycle of the carrier would look like given that the signal is just made up of ones and zeros. The final design (as far as I have gone) incorporates a synchronizing latch so the signals only change at the "zero" of the modulator. Simon Engineering is the art of making what you want from what you can get at a profit. I like Polywell Fusion. ___ 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] Anyone (ideally in the UK) got a spare rotary knob for the 5370B TI counter?
On 2 January 2017 at 18:21, Robert Atkinson wrote: > I've a spare knob and it's on it's way to Dave. f > Cheers Robert. I'll send you some money. Drop me a private email with your PayPal address. > 5370 counters do seem to run hot so I don't think you have a fault. As > suggested a little external airflow can help a lot. > > Robert G8RPI. > I'll have to check now I have put a variac on the supply voltage to the equipment. I set the variac last night, and have set my Tektrononix handheld to record min/max/average readings So far * Min = 216.71 * Max = 232.75 * Average = 227.88 * Min-Max=16.04. Obviously the change of 16.04 V is a bit lower than the real swing, as the variac is reducing this. Perhaps I might need to increase the variac voltage slightly, but I suspect that running a significantly lower voltage than before can only help. Maybe just a bit too low though. I also ordered a couple of those GPIB extenders. It would seem totally impossbile to get a GPIB cable on otherwise. Sticking the GPIB connect right next to the heatsink, with the cables coming out the side of the heatsink seems a bit odd. Unless there are any cables which come out the other side, so away from the heatsink. Anyway, I have an HP and a Keysight 10834A on order, which should give me enough room to get a GPIB cable out. A 5370B without a GPIB connection is a bit of a useless bit of kit. 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] FE-5650A option 58 tuning word for 10 MHz output
One could always wrap the assembly with its impaired mu metal shield in several layers of flexible magnetic shielding foil to regain the desired magnetic shielding e.Most such foils can be cut with scissors without significant effect on their magnetic properties. Bruce On Tuesday, 3 January 2017 11:46 AM, Bob Camp wrote: Hi > On Jan 2, 2017, at 5:02 PM, Bruce Griffiths > wrote: > > > Maybe a waterjet cutter would imapct less on the shielding properties of > tthe mumetal? > Maybe …. pretty good bet that the guys modifying these in their living room aren’t focused on much more than getting them working as fast as they possibly can. Bob > Bruce > > On Monday, January 02, 2017 12:58:55 PM Bob Camp wrote: >> Hi >> >>> On Jan 1, 2017, at 7:31 PM, wb6bnq wrote: >>> >>> Hello Mathias, >>> >>> I think you did not quite understand how the calibration process works >>> with that unit. The factory procedure is to set the pot to minimum and >>> then bring the DDS up to the step that produces the closest ___ 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-5650A option 58 tuning word for 10 MHz output
Hi > On Jan 2, 2017, at 5:02 PM, Bruce Griffiths > wrote: > > > Maybe a waterjet cutter would imapct less on the shielding properties of > tthe mumetal? > Maybe …. pretty good bet that the guys modifying these in their living room aren’t focused on much more than getting them working as fast as they possibly can. Bob > Bruce > > On Monday, January 02, 2017 12:58:55 PM Bob Camp wrote: >> Hi >> >>> On Jan 1, 2017, at 7:31 PM, wb6bnq wrote: >>> >>> Hello Mathias, >>> >>> I think you did not quite understand how the calibration process works >>> with that unit. The factory procedure is to set the pot to minimum and >>> then bring the DDS up to the step that produces the closest ___ 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] new year crashes
Make that a dual rate moon camera.These were used to measure variations in Earth's rotation period. Bruce On Tuesday, 3 January 2017 11:10 AM, Bruce Griffiths wrote: Carter did have a couple of small historic brass transit instruments which were never used by them.They also used to have a spectroheliograph which was used. Its long since been dismantled.Ther was also a lunar camera complete with alodined aluminium plate. Bruce On Tuesday, 3 January 2017 10:35 AM, Will Kimber wrote: Apologies Bruce, It is a good many years since I was there last. Cheers, Will On 01/03/2017 12:40 AM, Bruce Griffiths wrote: > You mean the Dominion observatory surely not Carter. It was close by and also > had a Danjon Astrolabe. > Bruce > > ___ 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] new year crashes
Carter did have a couple of small historic brass transit instruments which were never used by them.They also used to have a spectroheliograph which was used. Its long since been dismantled.Ther was also a lunar camera complete with alodined aluminium plate. Bruce On Tuesday, 3 January 2017 10:35 AM, Will Kimber wrote: Apologies Bruce, It is a good many years since I was there last. Cheers, Will On 01/03/2017 12:40 AM, Bruce Griffiths wrote: > You mean the Dominion observatory surely not Carter. It was close by and also > had a Danjon Astrolabe. > Bruce > > ___ 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-5650A option 58 tuning word for 10 MHz output
Maybe a waterjet cutter would imapct less on the shielding properties of tthe mumetal? Bruce On Monday, January 02, 2017 12:58:55 PM Bob Camp wrote: > Hi > > > On Jan 1, 2017, at 7:31 PM, wb6bnq wrote: > > > > Hello Mathias, > > > > I think you did not quite understand how the calibration process works > > with that unit. The factory procedure is to set the pot to minimum and > > then bring the DDS up to the step that produces the closest frequency > > just below the wanted one and then use the C-field pot as the final > > tweak. > > > > The "R" value is composed of a number of factors that can only be > > determined after the Rb cell is made. A number of variables, in the Rb > > cell itself, will determine the actual "ON" resonance frequency and that > > is what is programmed into the "R" number at the end of final assembly. > > > > That "R" number is actually the Rb frequency divided by 136 plus the > > upward fine tuning of the C-field pot. See PDF page 16 & 17 of the > > attached PDF operational manual for the FEI-5650. The only difference > > between all the variants comes after the Physics Package as shown on PDF > > page 16 block diagram. > > > > The "F" number is truly a 32 bit number, not just the first 8 digits but > > all 16 of them. > > > > Your problem is being able to have a frequency reference that is, > > obviously, way better then the Rb. As Cesium and Hydrogen references are > > quite expensive that leaves just the GPS satellites as the only other > > reference available that will do the job. Of course that entails more > > than just the GPS "timing" receiver as you will need some other equipment > > to help in the comparison process. Also it takes time to do many small > > adjustments to achieve that final comparison. It won't happen in just > > one day. > > > > It would probably have been better to purchase one of the Rb's that > > already output 10 MHz instead of hacking the option 58. BUT that is just > > my opinion. > This heads you down another rabbit hole. Since the 10 MHz output units sell > better than the PPS only versions, there is a cottage industry going to > convert one to the other. Parts are missing on the board to make a “proper” > 10 MHz unit. The conversion often is a bit ugly. No matter how well it is > done electrically, bashing a hole in the magnetic shield case for the SMA > is a really bad idea unless you have the proper gear to heat create it > after you are done. > > So yes, the 10 MHz version is a better way to go, but only if it came from > the factory as a 10 MHz unit ….. > > Bob > > > Good luck, > > > > Bill HoulneWB6BNQ > > > > Mathias Weyland wrote: > >> Hello guys > >> > >> I'm new to this list. I got myself a FE-5650A Rubidium Standard off of > >> ebay. It's the "option 58" 1 pps output variant, hence I have to modify > >> the tuning word used in the DDS phase accumulator to get 10 MHz out. I > >> found a vast amount of awesome descriptions on how to do that on the web > >> and in particular on this list. One write-up that stood out was this one > >> by Mark Sims: > >> > >> http://www.mail-archive.com/time-nuts@febo.com/msg13486.html > >> > >> I think I can pull this off since everything is documented so nicely. > >> However, I'm having trouble calculating the right tuning word and this > >> is why: Mark notes that the reference frequency reported by the unit is > >> the one with the C-field pot at the lowest frequency position. He gives > >> a number of suggestions on how to deal with that. Since I didn't get > >> that hydrogen maser for Christmas, the best approach seems to be "to > >> calculate the true reference frequency from the saved (minimum C- field) > >> R=reference frequency and F=divisor word and use that value to calculate > >> divisor words." I don't understand how the saved minimum C-field > >> reference ties into this calculation. > >> > >> My approach would have been to calculate the true reference frequency > >> from the saved divisor alone, ignoring the minimum C-field calculation. > >> I don't see how the minimum C-field reference frequency would help me > >> since the C-field pot is not in the min position anymore due to factory > >> tweaking. To be specific, this is what I would do: > >> > >> The unit returns the following string upon 'S': > >> > >> OK50255055.760840Hz F=2ABB5046B34A2E00 > >> > >> Now based on this, the tuning word should be coded in the first 8 > >> characters, of F, i.e. '2ABB5046'. I'm a bit confused about the > >> remaining characters being non-zero. Any documentation I came across has > >> a number that ends in 8 zeroes... In any case, 0x2ABB5046 is 716918854 > >> in decimal and the resolution would therefore be > >> > >> 2^23 / 716918854 = approx. 0.0117 Hz which makes sense. > >> > >> The physics package would then output a frequency of > >> > >> f_ref = (2^23 / 716918854) * 2^32 = approx. 50255055.809934 Hz > >> > >> This is higher than the r
Re: [time-nuts] Line Voltage - USA
Another one of those fascinating "threads!" I have lived through the claimed 110, 117 and 120 volt periods and have been apparently lucky enough to not have suffered any device damage. At present I live on a hill and do worry about lightning strikes to ham radio antennas. The last time I counted I had over 20 standard eight foot plated ground rods driven at various places and the entrance point of these antennas to the house is protected by an additional 6 rods. All wiring in the house is either thin wall tubing or other armored cable. Thus I effectively have building perimeter protection as well. All grounds are tied together along with the power neutral. I also have an automatic transfer backup alternator with separate ground also tied to the entire system. I do disconnect antennas during storm threats but in the past thirty years have yet to have any "over voltage" damage. From time to time I do check the line voltage but not with any NBS standard voltmeter and have found that it does "drift" between 120 and 126 which I feel is outstanding given the general circumstances which include being several miles from the distribution point along a rural road and the possibility of some fairly demanding motor starting loads that I deal with. My input panel is over 200 ft. from the farmer's electric co-op transformer which I used to share with two neighbors but now I have "my own." Yes, I do have lightning rod protection. 73 Lee K9WRU - Original Message - From: Poul-Henning Kamp To: Discussion of precise time and frequency measurement , Chuck Harris Sent: Mon, 02 Jan 2017 12:55:58 -0500 (EST) Subject: Re: [time-nuts] Line Voltage - USA In message <586a8b40.4050...@erols.com>, Chuck Harris writes: >Back in the dark ages of ~220V electrical distribution systems in >Europe, the reaping due to unintentional grounding of a ~220V wire >was so common and extreme, whole house ground fault interrupters >were mandated for all residential/small business power systems >therein. Close, but no cigar. The main problem was that in many countries outlets did not have a protective ground terminal. That meant that an internal fault in your appliance had a 50/50 chance of lighting up some exterior metal part you could touch. The "obvious solution" isn't obvious in countries where the geography does not allow you to obtain proper "protective ground". Norway being a good example. But even countries with the "obvious solution" of protective ground in all outlets saw problems, because it took 10-16 ampere misdirected current to blow the fuse, and you can light most flameable stuff with a lot less energy than that. The "Residual Current Device" solved both problems. RCD's even protect you from internal faults where proper protective ground is not available, by providing neutral from "outside" the RCD as PG in the installation. You'll still be (horribly!) exposed of an accident in the distribution grid (or lightning!) fires up the neutral, but that's simply life - or death - without a grounding rod. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts 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] new year crashes
Apologies Bruce, It is a good many years since I was there last. Cheers, Will On 01/03/2017 12:40 AM, Bruce Griffiths wrote: You mean the Dominion observatory surely not Carter. It was close by and also had a Danjon Astrolabe. Bruce ___ 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] new year crashes
It's not the fibre-it's the equipment on the end of it-specifically the multiplex equipment. And with path switching where differing eqpt was used on different links. you can guess the result! Different technologies these days but the terminal eqpts, (where your packets are injected/extracted to/from all the rest) collectively are the major contributors to end-to-end latency and its 'variablilty'. DaveB, NZ -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Hal Murray Sent: Monday, 2 January 2017 11:48 p.m. To: Discussion of precise time and frequency measurement Cc: hmur...@megapathdsl.net Subject: Re: [time-nuts] new year crashes tract...@ihug.co.nz said: > The 'landline' networks also have significant (and variable) latency. > ISTR measuring a maximum of around 400/500 mSec some years ago on a > WN-CH digital link. Minimum over the test period of a week was nearer 250 > mSec a few days > later. How can they get a delay that long? Satellite link? Fiber is 5 microseconds per km. So 1000 km is 5 ms. -- 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.
Re: [time-nuts] EFOS2 MASER turns 34!
Corby Congratulations on keeping the Maser going. Pretty amazing. You should check it against wwvb to make sure its accurate. Chuckle. Regards Paul WB8TSL On Mon, Jan 2, 2017 at 2:42 PM, Tim Shoppa wrote: > Very nice report, Corby! > > When I was in grad school back in the 90's, doing vacuum pump work was a > very menial task usually assigned to grad students, so naturally I became > quite familiar with it :-). Especially cleaning up messes with decrepit old > experimental systems! > > I think back to those days and maintaining an already-functioning H-Maser > actually seems perfectly feasible in the long term. > > The tight geometry of the copper package of a H-Maser sure seems a lot more > feasible than the other atomic clocks which are way more hi-tech stuff. > That said, machining the copper would be way beyond my ability! > > I also did get to work some plasma physics experiments where we used > kettles - literally large industrial cooking kettles, with some hacked-in > brazed-shut machining for the various probes and plumbing. Maybe if there > was some way to homebrew a primitive H-Maser with that low level of > construction competence I could give it a try! > > Please share more tales/pics of your H-Maser experience! > > Tim N3QE > > On Mon, Jan 2, 2017 at 1:18 PM, wrote: > > > Happy Birthday EFOS2 Maser! > > > > The EFOS2 active hydrogen Maser at my place just turned 34 years old! > > Pretty impressive reliability. > > It is an Oscilloquartz Maser, they are now called T4 Science. > > I know a guy in Norway that bought the refurbished EFOS3 Maser last > > year directly from T4 Science! It is 32 Years old! > > I have had the EFOS2 running here pretty much continuously since > > Sept 2007. > > I've had to refill the Hydrogen bottle 3 times. > > replaced ion pumps 4 times (requires a CLEAN vacuum pumping system) > > Had to repair one of the ion pump supplies (bad capacitor) > > Also removed original 1 transistor power oscillator that was used to > > drive the discharge providing the atomic Hydrogen. > > I replaced it with a custom class A oscillator amplifier. > > It uses an Oscilloquartz B5400 Quartz oscillator that has aged very > > little since 2007! > > > > Cheers, > > > > Corby Dawson > > > > ___ > > 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] EFOS2 MASER turns 34!
Very nice report, Corby! When I was in grad school back in the 90's, doing vacuum pump work was a very menial task usually assigned to grad students, so naturally I became quite familiar with it :-). Especially cleaning up messes with decrepit old experimental systems! I think back to those days and maintaining an already-functioning H-Maser actually seems perfectly feasible in the long term. The tight geometry of the copper package of a H-Maser sure seems a lot more feasible than the other atomic clocks which are way more hi-tech stuff. That said, machining the copper would be way beyond my ability! I also did get to work some plasma physics experiments where we used kettles - literally large industrial cooking kettles, with some hacked-in brazed-shut machining for the various probes and plumbing. Maybe if there was some way to homebrew a primitive H-Maser with that low level of construction competence I could give it a try! Please share more tales/pics of your H-Maser experience! Tim N3QE On Mon, Jan 2, 2017 at 1:18 PM, wrote: > Happy Birthday EFOS2 Maser! > > The EFOS2 active hydrogen Maser at my place just turned 34 years old! > Pretty impressive reliability. > It is an Oscilloquartz Maser, they are now called T4 Science. > I know a guy in Norway that bought the refurbished EFOS3 Maser last > year directly from T4 Science! It is 32 Years old! > I have had the EFOS2 running here pretty much continuously since > Sept 2007. > I've had to refill the Hydrogen bottle 3 times. > replaced ion pumps 4 times (requires a CLEAN vacuum pumping system) > Had to repair one of the ion pump supplies (bad capacitor) > Also removed original 1 transistor power oscillator that was used to > drive the discharge providing the atomic Hydrogen. > I replaced it with a custom class A oscillator amplifier. > It uses an Oscilloquartz B5400 Quartz oscillator that has aged very > little since 2007! > > Cheers, > > Corby Dawson > > ___ > 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] EFOS2 MASER turns 34!
Happy Birthday EFOS2 Maser! The EFOS2 active hydrogen Maser at my place just turned 34 years old! Pretty impressive reliability. It is an Oscilloquartz Maser, they are now called T4 Science. I know a guy in Norway that bought the refurbished EFOS3 Maser last year directly from T4 Science! It is 32 Years old! I have had the EFOS2 running here pretty much continuously since Sept 2007. I've had to refill the Hydrogen bottle 3 times. replaced ion pumps 4 times (requires a CLEAN vacuum pumping system) Had to repair one of the ion pump supplies (bad capacitor) Also removed original 1 transistor power oscillator that was used to drive the discharge providing the atomic Hydrogen. I replaced it with a custom class A oscillator amplifier. It uses an Oscilloquartz B5400 Quartz oscillator that has aged very little since 2007! Cheers, Corby Dawson ___ 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] Line Voltage - USA
In message , Tim Shoppa writes: >What modern loads are actually sensitive to high (say, +10 to +20%) line >voltage? In EU you're supposed to have 230V +/- 6% in your outlet. The way this was arrived at was: A lot of europe used 220V +/- 10% = [198..242] V Brittain used 240V +/- 10% = [216..264] V Take the average of the two, and use the low max and high min as limits QED: 230V +/- 6% = [216..244] -- 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] Line Voltage - USA
What modern loads are actually sensitive to high (say, +10 to +20%) line voltage? Old incandescent light bulbs were among the most sensitive loads in the past (so much so, that 130V light bulbs were commonly available from the industrial suppliers). I would naively expect the modern CFL's and LED replacements to be fine with higher line voltage because they have their own built-in switching regulation. A lot of modern electronic equipment with switching supplies, are just fine at +20% line voltage and may even run cooler. Tim N3QE On Sun, Jan 1, 2017 at 11:49 PM, Bill Byrom wrote: > There are a couple of recent threads concerning the power line mains > voltage standards. After a bit of research and thinking, I have found > that this is a complex topic. The simple answer is: > > > * The standard in the US for the past 50 years has been 120/240 V +/- 5% > RMS at the service entrance to the building. This is a range of > 114/228 V to 126/252 V. > * The load voltage could be as low as 110/220 V and as high as 125/250 V > and be within specifications. > > > There are two voltage measurement points to consider: > > (1) Service voltage: This is the RMS voltage measured at the service > entrance to the building (at the metering point). > (2) Utilization voltage: This is the RMS voltage measured at the load. > It might be measured at an unused socket in a power strip feeding > several pieces of electronic equipment, for example. There are of > course many different utilization voltages present in a home or > business, depending on where you make the measurement. > > > Most US homes and small businesses are powered by what is commonly > called a "split-phase" 240 V feed. The final distribution system > transformer has a 240 V center-tapped secondary. The center tap is > grounded, and three wires are fed to the building (actually it might be > up to around 6 houses): > (1) Leg L1 or phase A (red wire) -- This wire will measure 120 V to the > neutral or 240 V to Leg L2. > (2) Neutral (white wire) -- This wire is grounded at the distribution > system and at the service entrance to the building. > (3) Leg L2 phase B (black wire) -- This wire will measure 120 V to the > neutral or 240 V to Leg L1. > > > Large appliances and HVAC systems are usually connected across L1-L2 > (240 V), while most sockets are on circuits either connected across L1- > neutral (120 V) or L2-neutral (120 V). > > > The voltages I have described are the current standardized values for > the service voltage which have been in general use for about 50 years > (120/240 V +/- 5%). I believe that the original systems installed before > 1940 were designed for a 110/220 V nominal service voltage, but after a > report in 1949 the nominal service voltage was increased to 117/234 V, > as specified in ANSI C84.1-1954. After research in actual buildings, in > the 1960's the nominal service voltage was increased again, to 120/240 V > in the ANSI C84.1-1970 standard. The purpose is to keep the utilization > voltage at the load above 110/220 V. > > > The voltage at the service entrance should in most cases be in Range A > (120/240V +/-5%). On each 120V leg the service voltage should therefore > be between 114 and 126 V. The utilization voltage at the load should be > between 110 and 125 V due to losses in building wiring. > > > See details of the current specifications at: > > http://www.pge.com/includes/docs/pdfs/mybusiness/ > customerservice/energystatus/powerquality/voltage_tolerance.pdf > > > These voltage specifications were designed for resistive loads and > measurement of the true RMS voltage. In most electronic equipment built > over the past 50 years, the power supply input circuitry is basically a > rectifier connected to a smoothing capacitor. This leads to high input > current surges during the peaks of the waveform, so that the peak > voltage is reduced much more by the building wiring resistance than if > the load was resistive for the same power consumption. > > > So the waveform shape at different utilization locations in a building > (with active equipment loads) may be different, so the voltage measured > by different AC measuring instruments can differ. Many meters are full > wave average measuring but calibrated so they only read RMS voltage > correctly on pure sinewaves. Other meters are true RMS measuring and > will read very close the correct RMS voltage even if the waveform is > distorted. > -- > > Bill Byrom N5BB > > > > > > On Sun, Jan 1, 2017, at 12:16 PM, CIW308 VE6OH wrote: > > > Mark, > > > > > > CSA have standards for over and under voltage, Typical no more that 3% > > over and 5% under if memory serves me. > > > > > > This might help ( > > > http://www.safetyauthority.ca/sites/default/files/csa- > fia3660-voltagedropcalc.pdf > > ) > > > The power companies here in Alberta are generally good about fixing > > > problems with line regulation. > > > There can be problems with industrial are
Re: [time-nuts] Line Voltage - USA
In message <586a8b40.4050...@erols.com>, Chuck Harris writes: >Back in the dark ages of ~220V electrical distribution systems in >Europe, the reaping due to unintentional grounding of a ~220V wire >was so common and extreme, whole house ground fault interrupters >were mandated for all residential/small business power systems >therein. Close, but no cigar. The main problem was that in many countries outlets did not have a protective ground terminal. That meant that an internal fault in your appliance had a 50/50 chance of lighting up some exterior metal part you could touch. The "obvious solution" isn't obvious in countries where the geography does not allow you to obtain proper "protective ground". Norway being a good example. But even countries with the "obvious solution" of protective ground in all outlets saw problems, because it took 10-16 ampere misdirected current to blow the fuse, and you can light most flameable stuff with a lot less energy than that. The "Residual Current Device" solved both problems. RCD's even protect you from internal faults where proper protective ground is not available, by providing neutral from "outside" the RCD as PG in the installation. You'll still be (horribly!) exposed of an accident in the distribution grid (or lightning!) fires up the neutral, but that's simply life - or death - without a grounding rod. -- 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] FE-5650A option 58 tuning word for 10 MHz output
Hi > On Jan 1, 2017, at 7:31 PM, wb6bnq wrote: > > Hello Mathias, > > I think you did not quite understand how the calibration process works with > that unit. The factory procedure is to set the pot to minimum and then bring > the DDS up to the step that produces the closest frequency just below the > wanted one and then use the C-field pot as the final tweak. > > The "R" value is composed of a number of factors that can only be determined > after the Rb cell is made. A number of variables, in the Rb cell itself, > will determine the actual "ON" resonance frequency and that is what is > programmed into the "R" number at the end of final assembly. > > That "R" number is actually the Rb frequency divided by 136 plus the upward > fine tuning of the C-field pot. See PDF page 16 & 17 of the attached PDF > operational manual for the FEI-5650. The only difference between all the > variants comes after the Physics Package as shown on PDF page 16 block > diagram. > > The "F" number is truly a 32 bit number, not just the first 8 digits but all > 16 of them. > > Your problem is being able to have a frequency reference that is, obviously, > way better then the Rb. As Cesium and Hydrogen references are quite > expensive that leaves just the GPS satellites as the only other reference > available that will do the job. Of course that entails more than just the > GPS "timing" receiver as you will need some other equipment to help in the > comparison process. Also it takes time to do many small adjustments to > achieve that final comparison. It won't happen in just one day. > > It would probably have been better to purchase one of the Rb's that already > output 10 MHz instead of hacking the option 58. BUT that is just my opinion. > This heads you down another rabbit hole. Since the 10 MHz output units sell better than the PPS only versions, there is a cottage industry going to convert one to the other. Parts are missing on the board to make a “proper” 10 MHz unit. The conversion often is a bit ugly. No matter how well it is done electrically, bashing a hole in the magnetic shield case for the SMA is a really bad idea unless you have the proper gear to heat create it after you are done. So yes, the 10 MHz version is a better way to go, but only if it came from the factory as a 10 MHz unit ….. Bob > Good luck, > > Bill HoulneWB6BNQ > > Mathias Weyland wrote: > >> Hello guys >> >> I'm new to this list. I got myself a FE-5650A Rubidium Standard off of ebay. >> It's the "option 58" 1 pps output variant, hence I have to modify the tuning >> word used in the DDS phase accumulator to get 10 MHz out. I found a vast >> amount >> of awesome descriptions on how to do that on the web and in particular on >> this >> list. One write-up that stood out was this one by Mark Sims: >> >> http://www.mail-archive.com/time-nuts@febo.com/msg13486.html >> >> I think I can pull this off since everything is documented so nicely. >> However, >> I'm having trouble calculating the right tuning word and this is why: Mark >> notes >> that the reference frequency reported by the unit is the one with the C-field >> pot at the lowest frequency position. He gives a number of suggestions on >> how to >> deal with that. Since I didn't get that hydrogen maser for Christmas, the >> best >> approach seems to be "to calculate the true reference frequency from the >> saved >> (minimum C-field) R=reference frequency and F=divisor word and use that >> value to >> calculate divisor words." I don't understand how the saved minimum C-field >> reference ties into this calculation. >> >> My approach would have been to calculate the true reference frequency from >> the >> saved divisor alone, ignoring the minimum C-field calculation. I don't see >> how >> the minimum C-field reference frequency would help me since the C-field pot >> is >> not in the min position anymore due to factory tweaking. To be specific, >> this is >> what I would do: >> >> The unit returns the following string upon 'S': >> >> OK50255055.760840Hz F=2ABB5046B34A2E00 >> >> Now based on this, the tuning word should be coded in the first 8 >> characters, of >> F, i.e. '2ABB5046'. I'm a bit confused about the remaining characters being >> non-zero. Any documentation I came across has a number that ends in 8 >> zeroes... >> In any case, 0x2ABB5046 is 716918854 in decimal and the resolution would >> therefore be >> >> 2^23 / 716918854 = approx. 0.0117 Hz which makes sense. >> >> The physics package would then output a frequency of >> >> f_ref = (2^23 / 716918854) * 2^32 = approx. 50255055.809934 Hz >> >> This is higher than the reference given in the 'S' output, which is in line >> with >> what Mark wrote. However, scaling this with the average correction factor he >> gave yields >> >> f_ref * 1.2150 = approx. 50255055.917982 Hz >> >> Which is higher than what I would expect. Then again I'm not entirely sure >> wh
Re: [time-nuts] Line Voltage - USA
It's not a split phase system in US residential power, it is a center tapped 240V single phase system. Split phase systems have historically had a 45-90 degree phase difference between the split phases. The US system, depending on which wire lead you take as your reference, has a 0, or a 180 degree, phase difference. The reason it is done this way, is for safety. The center-tap of the mains transformer is grounded to earth, as is the neutral, and service entrance panel grounds. This way, if the power company installed grounding system is working properly, the highest voltage that any residential customer could accidentally encounter would be 120V to ground. (It is not an accident to go mucking around inside of a 240V range/dryer socket, or the service panel!) As it has been noted, if a US based system is defective, people can get hurt. The same is true for the European system. Back in the dark ages of ~220V electrical distribution systems in Europe, the reaping due to unintentional grounding of a ~220V wire was so common and extreme, whole house ground fault interrupters were mandated for all residential/small business power systems therein. And, in so far as properly functioning GFI protectors are in use, and can be maintained, they have been wildly successful! I will have to leave discussions of which system is better/safer/ cheaper/more reliable, for another time and forum...preferably one where there is beer and loud music. -Chuck Harris Gregory Maxwell wrote: > On Mon, Jan 2, 2017 at 4:49 AM, Bill Byrom wrote: >> Most US homes and small businesses are powered by what is commonly called a >> "split-phase" 240 V feed. The final distribution system transformer has a >> 240 V >> center-tapped secondary. The center tap is grounded, and three wires are fed >> to >> the building (actually it might be up to around 6 houses): (1) Leg L1 or >> phase A >> (red wire) -- This wire will measure 120 V to the neutral or 240 V to Leg >> L2. >> (2) Neutral (white wire) -- This wire is grounded at the distribution system >> and >> at the service entrance to the building. (3) Leg L2 phase B (black wire) -- >> This >> wire will measure 120 V to the neutral or 240 V to Leg L1. > > When someone here previously mentioned observing high voltage, one possible > cause > for this in this common "split-phase" configuration is that if the neutral > wire > is overloaded, damaged, poorly connected, or otherwise has high resistance, > the > voltage on the two legs will swing wildly and in opposite directions > depending on > load. > > So, e.g. if you put a 1kw load on L1 while L2 is nearly unloaded then perhaps > L1s > voltage drops to 108v while L2 rises to 132v. > > The reason for this is that, e.g. imagine that the neutral were removed > completely > you would effectively be connecting your appliances in a parallel-series > circuit > (all on L1 in parallel, all on L2 in parallel, the both in series) across the > 240v > feed. > > I've had issues with neutrals several times in the past, and in one instance, > temporarily dealt with it by moving as much of the load to 240v as I could, > manually balancing the remaining loads, and then using a digital multi-meter > to > dynamically control some additional load to keep the voltage sane on each > side. > > I think the fact that you can end up with a much higher voltages at the > outlet if > the neutral has problems is one of the more unfortunate properties of the > split-phase approach. ___ > 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] new year crashes
In my prior experience (from approx 5 to 20 years ago) actual wide area net work links delivered over fiber from commercial providers could have latencies of at least several times those figures. I seem to recall efforts were made to lower latencies for applications such as stock trading but I never had any exposure to those connections. Best regards Mark Spencer > > How can they get a delay that long? Satellite link? > > Fiber is 5 microseconds per km. So 1000 km is 5 ms. > > -- > 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] Update on TNS-BUF and TICC projects
Happy New Year, Time-Nuts! TAPR received the production run of TNS-BUF boards, and the engineering sample of the TICC, from our contract manufacturer last week. Both boards are nicely built and work as intended. TNS-BUF boards will be shipping soon to those who ordered; some may already have gone out. We will pull the trigger on the TICC production run by the end of the week, after doing a bit more preliminary work. Delivery is still scheduled for early February. Other news on the TICC front is that help from fellow time-nut Dave McQuate has yielded the last major module for the TICC software, so we will be able to ship the boards with fully-functional (though not guaranteed bug-free!) software loaded. Thanks, Dave! John ___ 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-5650A option 58 tuning word for 10 MHz output
On 2017-01-02 01:31, wb6bnq wrote: Hello Bill Thanks for your response and the pdf manual. There's lots of good information in there. You are certainly right in that there's a few things that I have not understood. Unfortunately this has not changed after having read your response: That "R" number is actually the Rb frequency divided by 136 plus the upward fine tuning of the C-field pot. See PDF page 16 & 17 of the attached PDF operational manual for the FEI-5650. In the comprehensive post[*] that I quote in my original request, Mark states that "THE R= REFERENCE FREQUENCY IS NOT THE FREQUENCY THAT THE PHYSICS PACKAGE IS SHIPPED TUNED TO!!! It is the frequency produced by the physics package at the minimum setting of the C-field potentiometer." This seems to be contradictory to what you wrote. Either the R value is determined at the C-field pot minimum frequency position as Mark stated, in which case it does not contain the upward C-field tweaking. Or it is determined after the final tweaking as you say. Either way I don't understand how to incorporate the R reference frequency into my calculations, which is what Mark seems to be suggesting. The "F" number is truly a 32 bit number, not just the first 8 digits but all 16 of them. The F number has 16 hex digits. Since each of those digits represents a nibble (i.e. half a byte, 4 bits), I end up with 16*4 = 64 bits. Not just 32. The first 8 digits of the F number however represent a 32 bit number, which is also the size of the the phase accumulator in the AD9830 which makes sense in my opinion. I think I absolutely failed to grasp what you're trying to tell me here :-( Re-reading the paragraph in [*] that starts with "You can set the divisor" did clear up something for me though -- looks like there's nothing weird with the F-number stored in my unit; the last byte is indeed 0x00. I still don't quite understand why this parameter is potentially stored at a higher precision than what the DDS can deliver. It would probably have been better to purchase one of the Rb's that already output 10 MHz instead of hacking the option 58. BUT that is just my opinion. You are probably right on that, yet getting any of those surplus standards off of ebay seems to be a bit of a hit-or-miss thing anyway. At least I get the learning experience, that's gotta count for something :-). Thanks again for your response and best regards 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.
Re: [time-nuts] Graphs
Hal! Good work! On 01/02/2017 01:09 PM, Hal Murray wrote: Here is data from a system using Google's NTP servers. http://users.megapathdsl.net/~hmurray/time-nuts/leap/ntp-goog-leap.png The Offset is the view from another system. The drift is from the system itself. Google said 13.9 uSec/sec. That matches the step in the drift. Note the overshoot at the end of the smear. It's about 50 ms. There is a similar blip at the start of the smear, but it's harder to see when it's riding on top of the sloped line. There is a smoothed initial end and attempt to do it at the end, but they cross-over is too late as it closes the loop again so it leaves some The NIST UT1 server smeared the second over a whole day. ?? http://users.megapathdsl.net/~hmurray/time-nuts/leap/UT1-SF-leap.png That's the consequence of Judah Levines approach to interpolate between the projected UT1 offsets, which is estimated per day. Somebody asked about systems that "freeze" the clock for a second. Linux, NetBSD, and FreeBSD all stepped the clock back. An OpenBSD system was off by a second for about 4 hours. Oups. There is still things to be done. The NTP kernel module actualy knows about the leap second, so if you also readout the data from the kernel you can get correct date. It's a matter of doing the coding. We've done that at work and it was fairly trivial. There used to be a bug/misfeature in glibc for Linux which didn't expose the new interface. This was due to the misconception that libc would know and kernel headers should be supplied by libc rather than with the kernel. Ah well. It works if the libc is updated with the kernel, but obviously it wasn't. 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] Leap second briefly catches out computer firm
Leap second briefly catches out computer firm - Web firm Cloudflare was briefly caught out by the leap second added to the end of 2016. http://www.bbc.co.uk/news/technology-38488246?ocid=socialflow_twitter Not the first, and won't be the last! Happy New Year! David -- SatSignal Software - Quality software written to your requirements Web: http://www.satsignal.eu Email: david-tay...@blueyonder.co.uk Twitter: @gm8arv ___ 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] MTI 240 OCXO, anyone?
An Oscilloquartz 8660 is its equivalent... OK, slightly worse. On Mon, Jan 2, 2017 at 12:05 AM, Bruce Lane wrote: > Happy New Year, fellow time-tickers! > > Would anyone happen to have a spare MTI 240 series OCXO, 10MHz output? > I'm looking to upgrade my TS2100. > > Failing the MTI, what alternates will work? I'd be very surprised if > Vectron didn't have an equivalent. > > Thanks much. > > -- > --- > Bruce Lane, ARS KC7GR > http://www.bluefeathertech.com > kyrrin (at) bluefeathertech dot com > "Quando Omni Flunkus Moritati" (Red Green) > ___ > 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] Graphs
Here is data from a system using Google's NTP servers. http://users.megapathdsl.net/~hmurray/time-nuts/leap/ntp-goog-leap.png The Offset is the view from another system. The drift is from the system itself. Google said 13.9 uSec/sec. That matches the step in the drift. Note the overshoot at the end of the smear. It's about 50 ms. There is a similar blip at the start of the smear, but it's harder to see when it's riding on top of the sloped line. The NIST UT1 server smeared the second over a whole day. ?? http://users.megapathdsl.net/~hmurray/time-nuts/leap/UT1-SF-leap.png Somebody asked about systems that "freeze" the clock for a second. Linux, NetBSD, and FreeBSD all stepped the clock back. An OpenBSD system was off by a second for about 4 hours. -- 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] new year crashes
You mean the Dominion observatory surely not Carter. It was close by and also had a Danjon Astrolabe. Bruce On Tuesday, 3 January 2017 12:10 AM, Hal Murray wrote: tract...@ihug.co.nz said: > The 'landline' networks also have significant (and variable) latency. ISTR > measuring a maximum of around 400/500 mSec some years ago on a WN-CH digital > link. Minimum over the test period of a week was nearer 250 mSec a few days > later. How can they get a delay that long? Satellite link? Fiber is 5 microseconds per km. So 1000 km is 5 ms. -- 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.
Re: [time-nuts] FE-5650A option 58 tuning word for 10 MHz output
Hoi Mathias! Wie goht's wie stoht's? :-) On Sat, 31 Dec 2016 15:33:53 +0100 Mathias Weyland wrote: > I'm new to this list. I got myself a FE-5650A Rubidium Standard off of > ebay. > It's the "option 58" 1 pps output variant, hence I have to modify the > tuning > word used in the DDS phase accumulator to get 10 MHz out. May I ask what you want to achieve? Resp. what you need a 10MHz reference for? In general I would agree with Bill Houlne's comment that it's probably easier to use a different reference that already has a 10MHz output. Also keep in mind, that an output that has been designed as an PPS output might not work as well as an output for 10MHz. > On a slightly related note, I have cooked up a small PCB with a local 5V > regulator and status LEDs that mates with the amphenol connector used on this > standard. I have to complete the write-up on it and will probably put up a > video about the mod on my youtube channel; once this is done I'll be sitting > on > 9 spare boards since I got 10 boards done. If there is interest, I could send > off the spares without profit, i.e. for about 5 bucks or so. I imagine this > could be of use to those who have the same standard. The board doesn't do > anything funky, it is just neat. In any case I'd like to ask if it would be OK > to formally place this offer on the list once I got everything ready. I am not master of desaster on this list, but it's usually ok to offer this kind of stuff, as long as it is time-nut related. Gruess und guets neus! 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] new year crashes
tract...@ihug.co.nz said: > The 'landline' networks also have significant (and variable) latency. ISTR > measuring a maximum of around 400/500 mSec some years ago on a WN-CH digital > link. Minimum over the test period of a week was nearer 250 mSec a few days > later. How can they get a delay that long? Satellite link? Fiber is 5 microseconds per km. So 1000 km is 5 ms. -- 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] new year crashes
The 'landline' networks also have significant (and variable) latency. ISTR measuring a maximum of around 400/500 mSec some years ago on a WN-CH digital link. Minimum over the test period of a week was nearer 250 mSec a few days later. DaveB ChCh, NZ -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Will Kimber Sent: Monday, 2 January 2017 1:01 p.m. To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] new year crashes Geoff I have also noted the pips sound different and seem to recall an on air comment about using local time*. The last pip is not always longer. You have also got to watch out for them using off air Freeview satellite transmissions rebroadcast on normal radio stations! Cheers, Will ZL1TAO * Maybe from the Carter Observatory where the old solar transit was. I'm not suggesting that they use it still. On 01/02/2017 12:46 PM, Kiwi Geoff wrote: > Will Kimber wrote: >> If you listened to Radio New Zealand National news New Year's day >> morning you would have heard then stating there will be 7 pips at 1:00pm. >> >> However there were only 6 !!! So what happened? > I was listening to both of the above events too, and agree with your > comments Will. > > The following is just my "observations" over the last few years as a > keen RNZ listener, and so may not be correct to those in the know. > > To my ears, there are two "types" of Time Pips: > > The "normal" time pips sound like reasonably pure sine-waves of 1KHz, > and are always correct to my house standard, and would be derived from > the atomic clocks at: > > Measurement Standards Laboratory > Callaghan Innovation > PO Box 31 310 > Lower Hutt 5040 > New Zealand > > https://www.msl.irl.cri.nz/services/time-and-frequency > > The "other" time pips sound different, they appear to be shorter in > duration and more like a square-wave at 1KHz than a sine-wave. I > assume they are locally generated at RNZ and are used when the > land-line to Lower Hutt is broken by road-works, earthquakes, or a > digger driver with a careless hand ! > > In the past I have detected the "other" time pips drifting by about > half a second per day, so I assume it's a relatively simple XO that is > used rather than a GPS which I thought would have been a better option > for a standby reference. > > So my guess as to what is currently going on (for RNZ time pips) is > that they are using the backup system , which appears to be manually > set - and is yet to be manually set by a man! > > Maybe someone who knows someone in RNZ engineering, can give a more > accurate picture than just my conjecture. > > Regards, Geoff ( Christchurch, New Zealand ). > ___ > 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] Line Voltage - USA
On Mon, Jan 2, 2017 at 4:49 AM, Bill Byrom wrote: > Most US homes and small businesses are powered by what is commonly > called a "split-phase" 240 V feed. The final distribution system > transformer has a 240 V center-tapped secondary. The center tap is > grounded, and three wires are fed to the building (actually it might be > up to around 6 houses): > (1) Leg L1 or phase A (red wire) -- This wire will measure 120 V to the > neutral or 240 V to Leg L2. > (2) Neutral (white wire) -- This wire is grounded at the distribution > system and at the service entrance to the building. > (3) Leg L2 phase B (black wire) -- This wire will measure 120 V to the > neutral or 240 V to Leg L1. When someone here previously mentioned observing high voltage, one possible cause for this in this common "split-phase" configuration is that if the neutral wire is overloaded, damaged, poorly connected, or otherwise has high resistance, the voltage on the two legs will swing wildly and in opposite directions depending on load. So, e.g. if you put a 1kw load on L1 while L2 is nearly unloaded then perhaps L1s voltage drops to 108v while L2 rises to 132v. The reason for this is that, e.g. imagine that the neutral were removed completely you would effectively be connecting your appliances in a parallel-series circuit (all on L1 in parallel, all on L2 in parallel, the both in series) across the 240v feed. I've had issues with neutrals several times in the past, and in one instance, temporarily dealt with it by moving as much of the load to 240v as I could, manually balancing the remaining loads, and then using a digital multi-meter to dynamically control some additional load to keep the voltage sane on each side. I think the fact that you can end up with a much higher voltages at the outlet if the neutral has problems is one of the more unfortunate properties of the split-phase approach. ___ 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] Leap second NTP fail
The team I work with was forced to outsource the NTP service to a telco (the largest in the Netherlands). Too bad they didn't handle the leap second well. Some time after the leap second hundreds of servers and VM's reported NTP problems. ... sys.peer - stratum 15, last reached 28 secs ago, stratum is too high (max allowed is 9) (synchronized on ) sys.peer - stratum 15, last reached 44 secs ago, stratum is too high (max allowed is 9) (synchronized on ) sys.peer - stratum 15, last reached 44 secs ago, stratum is too high (max allowed is 9) (synchronized on ) sys.peer - stratum 15, last reached 38 secs ago, stratum is too high (max allowed is 9) (synchronized on ) sys.peer - stratum 15, last reached 22 secs ago, stratum is too high (max allowed is 9) (synchronized on ) sys.peer - stratum 15, last reached 27 secs ago, stratum is too high (max allowed is 9) (synchronized on ) sys.peer - stratum 15, last reached 58 secs ago, stratum is too high (max allowed is 9) (synchronized on ) ... Some applications did report an error in the log, but I didn't find any real problems (yet). ___ 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.
