Re: [time-nuts] WWVB phase modulation format?
> ... or I suppose we could ask. I did ask, using the contact email on the NIST page (John Lowe). I'll forward any replies to the list. Perhaps we could encourage a more ambitious DCF77-like scheme, if that's really not in the current plans for WWVB. Especially given the recent demise of Loran-C, a WWVB service with greater timing precision would certainly be welcome as a backup for GPS. Cheers, Peter ___ 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 phase modulation format?
> I believe what they were doing is applying a simple 180 deg phase shift to > the carrier (BPSK) during certain one second timecode intervals. I suppose this will help coherent receivers somewhat, but I was expecting something DCF77-like. A pity. Thanks for posting your data. You certainly have good WWVB reception. Attached is a plot of the real part of the demodulated signal after carrier estimation. They change the phase 100 ms after the second marker, halfway between the second marker and a potential change in amplitude back to full power. So the phase transition always occurs in the middle of a low-power interval. Cheers, Peter <>___ 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] Symetricom CSAC
Hello, Does anyone have any experience with the Symetricom Chip Scale Atomic Clock? Seems interesting. http://www.businesswire.com/news/home/20110118005182/en/Symmetricom-Announces-General-Availability-Industry%E2%80%99s-Commercially-Available-Chip Sam ___ 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] HP5370
Hello Norm, Do you still have the HP5370 for sale? Thanks, Sam W3OHM ___ 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 phase modulation format?
On Mar 11, 2012, at 12:53 PM, John Seamons wrote: > I took a look at this. Pictures and video here: http://jks.com > > I believe what they were doing is applying a simple 180 deg phase shift to > the carrier (BPSK) during certain one second timecode intervals. > Whether there was anything fancier going on or not (like what DCF77 does) I > couldn't tell immediately, although I did make a 192 ksps sound card > recording for future analysis. Okay, so I did a little analysis of the data. See the website for details. For the few minutes I recorded there was a fixed pattern of phase changes that repeated each minute. They did not seem related to the changing timecode. I tried interpreting the bits as various things, including ascii characters, but no luck. Maybe one of you will figure it out, or I suppose we could ask. ___ 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] Austron 1201A
Is an Austron 1201A of any use? I may be able to get one. What is a rational price? How difficult is it to get an analog output, so I don't have to use the chart recorder? I didn't see any output connectors on it. Any chance of documentation? Googling found nothing. Joe Gray W5JG ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] LORAN C in New Jersey??
nice a cs ref in the backyard On Sun, Mar 11, 2012 at 7:43 PM, Bill Riches wrote: > Again - test transmissions are from the USCG site at Wildwood Crest, NJ. > That was the old USCG engineering station which has been dismantled and the > only thing left is the 600+ foot tower and loran transmitter that was used > for engineering tests and as a back up if needed. I am 7 miles from the > site and last week it was putting in a 20 - 30/9 sig at my qth. > > 73, > > Bill Riches, WA2DVU > Cape May, NJ > > > > ___ > 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] DIY GPS-DO
On Sat, Mar 10, 2012 at 5:07 AM, Filip Ozimek wrote: > could you recommend me a good project of GPS-DO? I've got a GPS module with > 1PPS output and a 20 MHz VCXO. > As I understand to do a phaselock to 1 PPS signal one must build some kind of > digital PLL. But I'm not sure > how to calculate a correction signal to the VCXO and how to test such a > disciplined oscillator. THe references you got were good. But if you are looking for the big picture, it's simple. There are many methods but they are all much alike if you step back and look at what's really going on. What you need is a digital signal line that goes high on the leading edge ofht e PPS and then goes low on the next leading edge of the VCXO. Then you build a controller to keep the time signal is high at a constant. You can use a time to voltage converter and be 100% analog or you can go digital. The first thing you need is a divider. 20MHz is kind of fast. you might even go for a divide by 20. then your controller sees a more manageable 1Mhz. If the vxco is not ultra stable it is best to divide it down quite a bit. I assume this project is just for education and entertainment. If you really need a GPSDO in your llab it is cheaper and simpler to buy a Thunder both from eBay. You can buy one for many $120 and they are hard to build at that price. 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] LORAN C in New Jersey??
Again - test transmissions are from the USCG site at Wildwood Crest, NJ. That was the old USCG engineering station which has been dismantled and the only thing left is the 600+ foot tower and loran transmitter that was used for engineering tests and as a back up if needed. I am 7 miles from the site and last week it was putting in a 20 - 30/9 sig at my qth. 73, Bill Riches, WA2DVU Cape May, NJ ___ 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] Agilent 53230A Counter
Not sure, maybe through Agilent. Not through the factory, I tried.. Bye, Said Sent From iPhone On Mar 11, 2012, at 10:33, Magnus Danielson wrote: > On 03/11/2012 06:20 PM, Said Jackson wrote: >> 10811 ocxos are still made for Agilent today, they are used in instruments >> such as the 5052B. I have seen the assembly line a little while ago. >> >> Today's variants are supposed to have better phase noise. Not sure about >> stability, I would expect them to be equal or better. Good designs don't go >> away easily :) > > Are they commercially available? > > Cheers, > Magnus > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] WWVB phase modulation format?
On Mar 9, 2012, at 4:28 PM, Peter Monta wrote: > Interesting that WWVB is running a phase-modulation test---thanks for > the links. Is the signal format known? A quick search shows nothing > specific, just "we're testing". > > Could someone record a few minutes of the broadband signal so that > those of us without ready-to-hand LF receivers can have a look? > > Cheers, > Peter I took a look at this. Pictures and video here: http://jks.com I believe what they were doing is applying a simple 180 deg phase shift to the carrier (BPSK) during certain one second timecode intervals. Whether there was anything fancier going on or not (like what DCF77 does) I couldn't tell immediately, although I did make a 192 ksps sound card recording for future analysis. Apologies for the crude measurement and presentation. I had to throw this together in a hurry. ___ 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] found surfing the Agilent sites
hopefully not a repeat post http://metrologyforum.tm.agilent.com/bio-cutler.shtml ___ 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] Three HP oldies
101A https://plus.google.com/u/0/photos/111617808980322733757/albums/5718694502890226481 115CR https://plus.google.com/u/0/photos/111617808980322733757/albums/5718697892451866241 116AR https://plus.google.com/u/0/photos/111617808980322733757/albums/5718699462521152657 ___ 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] Agilent 53230A Counter
On 03/11/2012 06:20 PM, Said Jackson wrote: 10811 ocxos are still made for Agilent today, they are used in instruments such as the 5052B. I have seen the assembly line a little while ago. Today's variants are supposed to have better phase noise. Not sure about stability, I would expect them to be equal or better. Good designs don't go away easily :) Are they commercially available? Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Agilent 53230A Counter
10811 ocxos are still made for Agilent today, they are used in instruments such as the 5052B. I have seen the assembly line a little while ago. Today's variants are supposed to have better phase noise. Not sure about stability, I would expect them to be equal or better. Good designs don't go away easily :) Bye, Said Sent From iPhone On Mar 11, 2012, at 0:09, Frank Stellmach wrote: > Hello, > > Does anybody know details about the time interpolator in the 53230A? I did > not find service manuals online containing the 'Theory of Operation'. > > The 5370 interpolator obviously was well-respected for its high linearity and > low jitter, based upon the dual-vernier digital interpolator, but other T.I. > counters containing analogous capacitor-integrators often suffer from > non-linearities and higher jitter. > > As agilent obviously does not manufacture the 10811 OCXO anymore, what do > they use instead, and from which supplier? > > Frank > > ___ > 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] Agilent 53230A Counter
Frank Stellmach wrote: > The 5370 interpolator obviously was well-respected for its high > linearity and low jitter, based upon the dual-vernier digital > interpolator, but other T.I. counters containing analogous > capacitor-integrators often suffer from non-linearities and higher jitter. The interpolator in the 531XX series was similar to most of the other counters, being fairly basic and depending on frequent calibration to reduce the errors. I don't know anything about the current generation. They were designed in Asia by a completely different crew. There is virtually no institutional memory involved. Sadly, David Chu, the father of the 5370, was let go several years ago. AFAIK, he was not consulted by the division in Asia that currently builds counters. > As agilent obviously does not manufacture the 10811 OCXO anymore, what > do they use instead, and from which supplier? Drop in replacements for the 10811 have been available for years from several suppliers. The OCXO in the 53230 doesn't compare to the 10811. It's very likely something out of Asia. Rick ___ 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] Agilent 53230A Counter
On 03/11/2012 09:09 AM, Frank Stellmach wrote: Hello, Does anybody know details about the time interpolator in the 53230A? I did not find service manuals online containing the 'Theory of Operation'. The 5370 interpolator obviously was well-respected for its high linearity and low jitter, based upon the dual-vernier digital interpolator, but other T.I. counters containing analogous capacitor-integrators often suffer from non-linearities and higher jitter. The analogue capacitor-integrators have been made with better non-linearity and lower jitter since, so your statement regarding them is misleading. Check out the Wavecrest DTS series for instance. Built-in calibration has been used to increase linearity, but also the analog design has been designed for it. There is a number of other approaches to improved resolution, jitter, linearity or just implementation simplicity that has become popular as of late. As agilent obviously does not manufacture the 10811 OCXO anymore, what do they use instead, and from which supplier? There are many choices, but do not expect them to match up to the 10811. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Agilent 53230A Counter
Hello, Does anybody know details about the time interpolator in the 53230A? I did not find service manuals online containing the 'Theory of Operation'. The 5370 interpolator obviously was well-respected for its high linearity and low jitter, based upon the dual-vernier digital interpolator, but other T.I. counters containing analogous capacitor-integrators often suffer from non-linearities and higher jitter. As agilent obviously does not manufacture the 10811 OCXO anymore, what do they use instead, and from which supplier? Frank ___ 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.
