[time-nuts] Symmetricom 58532A and 58536A group delay figures
Assuming it does not snow again, should finish the cabling to the new rooftop tripod and switch to the new antenna and splitter tomorrow. For the LMR400 main run and jumpers is simple enough, will just measure. That leaves the antenna and splitter, both have and amp and bandpass filter and I am assuming a combined delay that is likely greater than the cable delay given the short runs. Nothing is listed in the datasheets, but they are the semi-marketing sheets (only a couple pages) rather than a proper datasheet. Anyone know what the delay for this amp and splitter is? Or better yet a delay v.s. temp plot? Thanks ___ 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] Symmetricom 58532A and 58536A group delay figures
cbr...@woods.net said: Anyone know what the delay for this amp and splitter is? Or better yet a delay v.s. temp plot? From: http://www.symmetricom.com/link.cfm?lid=9017 Group delay: 40 ns typical. There is a different version of the data sheet available at: http://www.rdrelectronics.com/skip/apr/58536a.pdf Group delay: 40 ns typical, all models -- 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] messy workbenches
Hi Brooke, I'm not sure I should have done that test as I scored 35. Hmmm... Rob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Brooke Clarke Sent: 29 September 2012 14:11 To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] messy workbenches Hi: Recently I've discovered Asperger's Syndrome. Although I don't meet all the criteria, I do have a number of the traits. One is living with clutter (this is different from obsessive hording). A common occupation is engineering. AS people are much more comfortable with things as opposed to people. People who work in technical fields or have strong interests, like extremely precise time, may also have this. To find out you can take an online test at: http://www.aspergerstestsite.com/ or read the Wiki page at: http://en.wikipedia.org/wiki/Asperger_syndrome and a movie: Mozart and the Whale that's about this. Have Fun, Brooke Clarke http://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html DaveH wrote: And Bob Pease trumps all: http://eetimes.com/electronics-blogs/other/4217103/How-messy-is-your-d esk- There is even a gallery of 24 of Engineering's messiest desks here: http://www.eetimes.com/electronics-blogs/social-mania-blog/4217145/Pho to-gal lery--Engineering-s-messiest-desks My primary love is music (analog synthesizers and digital instruments with recording) and the first messy desk pictured is from Christopher Nelson who designs the Sweetwater Sound Creation Station computers -- I own one and love it. It is ironic that: Pease was killed in the crash of his 1969 Volkswagen Beetle, on June 18, 2011. He was leaving a gathering in memory of Jim Williams, who was another well-known analog circuit designer. From Bob's wikipedia entry: http://en.wikipedia.org/wiki/Bob_Pease Dave (who has a messy workbench but I know where everything is!!!) -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Grant Saviers Sent: Friday, September 28, 2012 18:48 To: time-nuts@febo.com Subject: [time-nuts] messy workbenches George's is a far distant competitor to the bench of the late Jim Williams, see http://www.computerhistory.org/atchm/an-analog-life-rememberin g-jim-williams/ Which was on display at the Computer History Museum and just was returned to Linear Tech. Grant Saviers ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] E1938A PN measurments
Hi Close in, it looks like it's pretty much the crystal and the loading of the bridge oscillator. Bob On Sep 29, 2012, at 11:46 PM, Richard (Rick) Karlquist rich...@karlquist.com wrote: The E1938A uses a crystal that is basically the same as the 10811 crystal except that it is in a reduced height package. However the phase noise is not as good as a 10811 due to broadband noise in the automatic frequency control circuit. By the time I discovered this, it was too late to try to fix it. Rick Karlquist N6RK E1938A designer ___ 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] Symmetricom 58532A and 58536A group delay figures
We measured the delay on a couple of the splitters. I need to dig up the results, but I think the delay is around 7ns in both the 2 and 8 port units, and is pretty consistent port-to-port. I'll find the data and get it on the pages at febo.com. John On Sep 30, 2012, at 2:51 AM, Christopher Brown cbr...@woods.net wrote: Assuming it does not snow again, should finish the cabling to the new rooftop tripod and switch to the new antenna and splitter tomorrow. For the LMR400 main run and jumpers is simple enough, will just measure. That leaves the antenna and splitter, both have and amp and bandpass filter and I am assuming a combined delay that is likely greater than the cable delay given the short runs. Nothing is listed in the datasheets, but they are the semi-marketing sheets (only a couple pages) rather than a proper datasheet. Anyone know what the delay for this amp and splitter is? Or better yet a delay v.s. temp plot? Thanks ___ 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] messy workbenches
Hi Rob: For me it's been very helpful to understand myself. Note this is not something to be cured it's just the way some people are and the world needs those people. There a book look me in the eye that's a true story about the guy who built the special guitars for the rock group KISS. Have Fun, Brooke Clarke http://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html Rob Kimberley wrote: Hi Brooke, I'm not sure I should have done that test as I scored 35. Hmmm... Rob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Brooke Clarke Sent: 29 September 2012 14:11 To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] messy workbenches Hi: Recently I've discovered Asperger's Syndrome. Although I don't meet all the criteria, I do have a number of the traits. One is living with clutter (this is different from obsessive hording). A common occupation is engineering. AS people are much more comfortable with things as opposed to people. People who work in technical fields or have strong interests, like extremely precise time, may also have this. To find out you can take an online test at: http://www.aspergerstestsite.com/ or read the Wiki page at: http://en.wikipedia.org/wiki/Asperger_syndrome and a movie: Mozart and the Whale that's about this. Have Fun, Brooke Clarke http://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html DaveH wrote: And Bob Pease trumps all: http://eetimes.com/electronics-blogs/other/4217103/How-messy-is-your-d esk- There is even a gallery of 24 of Engineering's messiest desks here: http://www.eetimes.com/electronics-blogs/social-mania-blog/4217145/Pho to-gal lery--Engineering-s-messiest-desks My primary love is music (analog synthesizers and digital instruments with recording) and the first messy desk pictured is from Christopher Nelson who designs the Sweetwater Sound Creation Station computers -- I own one and love it. It is ironic that: Pease was killed in the crash of his 1969 Volkswagen Beetle, on June 18, 2011. He was leaving a gathering in memory of Jim Williams, who was another well-known analog circuit designer. From Bob's wikipedia entry: http://en.wikipedia.org/wiki/Bob_Pease Dave (who has a messy workbench but I know where everything is!!!) -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Grant Saviers Sent: Friday, September 28, 2012 18:48 To: time-nuts@febo.com Subject: [time-nuts] messy workbenches George's is a far distant competitor to the bench of the late Jim Williams, see http://www.computerhistory.org/atchm/an-analog-life-rememberin g-jim-williams/ Which was on display at the Computer History Museum and just was returned to Linear Tech. Grant Saviers ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Symmetricom 58532A and 58536A group delay figures
Found the data on the splitters: http://www.febo.com/pages/lab_documentation/gps_cable_delay/hp_gps_splitter/ My recollection was a bit off -- we saw about 22ns on the two-port 58535a and about 15ns on the 8-port 58517A. I would guess the 4-port unit would be similar. Unfortunately, I haven't been in a position to try to measure the delay through an antenna. John On Sep 30, 2012, at 2:51 AM, Christopher Brown cbr...@woods.net wrote: Assuming it does not snow again, should finish the cabling to the new rooftop tripod and switch to the new antenna and splitter tomorrow. For the LMR400 main run and jumpers is simple enough, will just measure. That leaves the antenna and splitter, both have and amp and bandpass filter and I am assuming a combined delay that is likely greater than the cable delay given the short runs. Nothing is listed in the datasheets, but they are the semi-marketing sheets (only a couple pages) rather than a proper datasheet. Anyone know what the delay for this amp and splitter is? Or better yet a delay v.s. temp plot? Thanks ___ 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] E1938A PN measurments
I recently modified an old 10811 to bring out the crystal leads on miniature coax (instead of having them connect to the oscillator circuit). This allowed me to measure the crystal's inherent flicker noise of frequency. The measurements indicate that the 10811 phase noise out to at least 100 Hz is entirely due to the crystal. An interesting aspect of flicker noise of frequency is that Allan deviation is independent of tau. Thus, just one number describes the crystal noise. Rick On 9/30/2012 4:44 AM, Bob Camp wrote: Hi Close in, it looks like it's pretty much the crystal and the loading of the bridge oscillator. Bob On Sep 29, 2012, at 11:46 PM, Richard (Rick) Karlquist rich...@karlquist.com wrote: The E1938A uses a crystal that is basically the same as the 10811 crystal except that it is in a reduced height package. However the phase noise is not as good as a 10811 due to broadband noise in the automatic frequency control circuit. By the time I discovered this, it was too late to try to fix it. Rick Karlquist N6RK E1938A designer ___ 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] Symmetricom 58532A and 58536A group delay figures
j...@febo.com said: My recollection was a bit off -- we saw about 22ns on the two-port 58535a and about 15ns on the 8-port 58517A. I would guess the 4-port unit would be similar. Interesting that it's so far off from the 40 ns in the data sheet. -- 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] E1938A PN measurments
Rick it is really fantastic to see Time Nuts occasionally discuse different aspects of products they actually designed. This form is really a treasure. In the future it would be interesting to here how you would approach the next quartz industry standard. The next generation Blue-Top or BVA. Thanks; Thomas Knox Date: Sun, 30 Sep 2012 10:03:03 -0700 From: rich...@karlquist.com To: time-nuts@febo.com Subject: Re: [time-nuts] E1938A PN measurments I recently modified an old 10811 to bring out the crystal leads on miniature coax (instead of having them connect to the oscillator circuit). This allowed me to measure the crystal's inherent flicker noise of frequency. The measurements indicate that the 10811 phase noise out to at least 100 Hz is entirely due to the crystal. An interesting aspect of flicker noise of frequency is that Allan deviation is independent of tau. Thus, just one number describes the crystal noise. Rick On 9/30/2012 4:44 AM, Bob Camp wrote: Hi Close in, it looks like it's pretty much the crystal and the loading of the bridge oscillator. Bob On Sep 29, 2012, at 11:46 PM, Richard (Rick) Karlquist rich...@karlquist.com wrote: The E1938A uses a crystal that is basically the same as the 10811 crystal except that it is in a reduced height package. However the phase noise is not as good as a 10811 due to broadband noise in the automatic frequency control circuit. By the time I discovered this, it was too late to try to fix it. Rick Karlquist N6RK E1938A designer ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Symmetricom 58532A and 58536A group delay figures
I think the usually quote worse case. Sent from my iPhone and Hunter Lambert is my hero! On Sep 30, 2012, at 12:03 PM, Hal Murray hmur...@megapathdsl.net wrote: j...@febo.com said: My recollection was a bit off -- we saw about 22ns on the two-port 58535a and about 15ns on the 8-port 58517A. I would guess the 4-port unit would be similar. Interesting that it's so far off from the 40 ns in the data sheet. -- 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] E1938A PN measurments
Hi ….. any bets on it being a triple oven? :) Bob On Sep 30, 2012, at 1:26 PM, Tom Knox act...@hotmail.com wrote: Rick it is really fantastic to see Time Nuts occasionally discuse different aspects of products they actually designed. This form is really a treasure. In the future it would be interesting to here how you would approach the next quartz industry standard. The next generation Blue-Top or BVA. Thanks; Thomas Knox Date: Sun, 30 Sep 2012 10:03:03 -0700 From: rich...@karlquist.com To: time-nuts@febo.com Subject: Re: [time-nuts] E1938A PN measurments I recently modified an old 10811 to bring out the crystal leads on miniature coax (instead of having them connect to the oscillator circuit). This allowed me to measure the crystal's inherent flicker noise of frequency. The measurements indicate that the 10811 phase noise out to at least 100 Hz is entirely due to the crystal. An interesting aspect of flicker noise of frequency is that Allan deviation is independent of tau. Thus, just one number describes the crystal noise. Rick On 9/30/2012 4:44 AM, Bob Camp wrote: Hi Close in, it looks like it's pretty much the crystal and the loading of the bridge oscillator. Bob On Sep 29, 2012, at 11:46 PM, Richard (Rick) Karlquist rich...@karlquist.com wrote: The E1938A uses a crystal that is basically the same as the 10811 crystal except that it is in a reduced height package. However the phase noise is not as good as a 10811 due to broadband noise in the automatic frequency control circuit. By the time I discovered this, it was too late to try to fix it. Rick Karlquist N6RK E1938A designer ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] messy workbenches
El 29/09/2012 19:11, Joe Leikhim escribió: I would have to agree that a lot of engineer and tech types fall into these categories. If not, we would probably not have and GPS satellites, cellphones and supersonic planes.(where is my hoverboard?) Not sure. Asperger is a type of autism, and although some geniouses along the history also seems to have suffered some degree of this syndrome, there are a lot of non-so-brilliant people that also suffers it (but since they are not geniouses, nobody has learn about them). In other hand, there have been also a lot of true geniouses that are a lot far from suffering nothing similar to that (for example, Richard Feynmann). Two nice examples of fictional people with that syndrome are Sheldon of Big Bang Theory (although they deny it) and the detective Monk. Best regards, Javier ___ 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] Messy benches
Don Latham's law of horizontal surfaces states Any bare horizontal surface immediately becomes covered with junk. I would offer a more general law: A N dimensional surface tends to attrack N+1 dimensional objects to the saturation limit. ___ 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] E1938A PN measurments
Would this characteristic be similar across all 10811s or would there be as much unit to unit variation as there is for aging and Allan Deviation? Ed On 9/30/2012 11:03 AM, Richard (Rick) Karlquist wrote: I recently modified an old 10811 to bring out the crystal leads on miniature coax (instead of having them connect to the oscillator circuit). This allowed me to measure the crystal's inherent flicker noise of frequency. The measurements indicate that the 10811 phase noise out to at least 100 Hz is entirely due to the crystal. An interesting aspect of flicker noise of frequency is that Allan deviation is independent of tau. Thus, just one number describes the crystal noise. Rick On 9/30/2012 4:44 AM, Bob Camp wrote: Hi Close in, it looks like it's pretty much the crystal and the loading of the bridge oscillator. Bob On Sep 29, 2012, at 11:46 PM, Richard (Rick) Karlquist rich...@karlquist.com wrote: The E1938A uses a crystal that is basically the same as the 10811 crystal except that it is in a reduced height package. However the phase noise is not as good as a 10811 due to broadband noise in the automatic frequency control circuit. By the time I discovered this, it was too late to try to fix it. Rick Karlquist N6RK E1938A designer ___ 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] Symmetricom 58532A and 58536A group delay figures
Interesting that it's so far off from the 40 ns in the data sheet. I think the usually quote worse case. Both data sheets said typical. Worst case makes sense for things like delays through digital gates where you have to add up the total delay to see if your design will meet timing. But if you are trying to correct for actual delays, the typicals are probably more useful. Note that typicals can change over time if the manufacturer switches to a newer/cheaper/faster process, or you get a batch from a different vendor. The numbers in the data sheet may not match current reality. -- 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] E1938A PN measurments
I only measured one 10811. However, John Vig's tutorial (available at IEEE UFFC) rather categorically states that piezoelectric resonators have flicker noise of frequency. What I measured was most closely related to phase noise, as opposed to Allan Deviation. Phase noise of 10811's is more consistent unit to unit than ADEV and certain more consistent than aging. BTW, ADEV at HP was measured against a special 10811 that was 500 Hz off frequency. I was never able to find out how they arrived at this golden unit. But it seems clear that it could not have been the best ever unit for ADEV, thus the real golden units that came down the pike were simply rated as ADEV too good to measure. I tried to get a project started where we would use a frequency synthesizer to do the offset. Then we could take the best units and compared them against each other. Then, as well accumulated test data, the cream would gradually rise to the top and we would have some true golden units. The problem was that there ADEV at those levels wasn't a money spec. Rick On 9/30/2012 12:16 PM, Ed Palmer wrote: Would this characteristic be similar across all 10811s or would there be as much unit to unit variation as there is for aging and Allan Deviation? Ed On 9/30/2012 11:03 AM, Richard (Rick) Karlquist wrote: I recently modified an old 10811 to bring out the crystal leads on miniature coax (instead of having them connect to the oscillator circuit). This allowed me to measure the crystal's inherent flicker noise of frequency. The measurements indicate that the 10811 phase noise out to at least 100 Hz is entirely due to the crystal. An interesting aspect of flicker noise of frequency is that Allan deviation is independent of tau. Thus, just one number describes the crystal noise. Rick On 9/30/2012 4:44 AM, Bob Camp wrote: Hi Close in, it looks like it's pretty much the crystal and the loading of the bridge oscillator. Bob On Sep 29, 2012, at 11:46 PM, Richard (Rick) Karlquist rich...@karlquist.com wrote: The E1938A uses a crystal that is basically the same as the 10811 crystal except that it is in a reduced height package. However the phase noise is not as good as a 10811 due to broadband noise in the automatic frequency control circuit. By the time I discovered this, it was too late to try to fix it. Rick Karlquist N6RK E1938A designer ___ 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] Symmetricom 58532A and 58536A group delay figures
With a warmed up tbolt and Lady Heather it is perfectly possible to measure/watch the delay by swapping the splitter in and out of the antenna cable chain. -- Björn Interesting that it's so far off from the 40 ns in the data sheet. I think the usually quote worse case. Both data sheets said typical. Worst case makes sense for things like delays through digital gates where you have to add up the total delay to see if your design will meet timing. But if you are trying to correct for actual delays, the typicals are probably more useful. Note that typicals can change over time if the manufacturer switches to a newer/cheaper/faster process, or you get a batch from a different vendor. The numbers in the data sheet may not match current reality. -- 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] E1938A PN measurments
On 09/30/2012 09:49 PM, Richard (Rick) Karlquist wrote: I only measured one 10811. However, John Vig's tutorial (available at IEEE UFFC) rather categorically states that piezoelectric resonators have flicker noise of frequency. What I measured was most closely related to phase noise, as opposed to Allan Deviation. Phase noise of 10811's is more consistent unit to unit than ADEV and certain more consistent than aging. BTW, ADEV at HP was measured against a special 10811 that was 500 Hz off frequency. I was never able to find out how they arrived at this golden unit. But it seems clear that it could not have been the best ever unit for ADEV, thus the real golden units that came down the pike were simply rated as ADEV too good to measure. I tried to get a project started where we would use a frequency synthesizer to do the offset. Then we could take the best units and compared them against each other. Then, as well accumulated test data, the cream would gradually rise to the top and we would have some true golden units. The problem was that there ADEV at those levels wasn't a money spec. With two such offset 10811s you could use DMTD methods or for that matter cross-correlation phase noise measures to more directly measure the units. That way you would have avoided the golden unit issue, since the phase noise of those would average out if treated well. Didn't you consider steps like that? That's what I do in my lab these days. 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] E1938A PN measurments
Rick I have some 10811's all below 1 E-12 in the 1 to 100 sec. range, a few as low as 4 E-13 at 10 seconds. How low have you seen, I have the opportunity to test 40+ units and hope to find a few even better ones. Any guidance will be appreciated. My best reference is 3 E-13 so any thing as good or better would have to be tested by some one else after initial test. Bert Kehren . In a message dated 9/30/2012 3:49:33 P.M. Eastern Daylight Time, rich...@karlquist.com writes: I only measured one 10811. However, John Vig's tutorial (available at IEEE UFFC) rather categorically states that piezoelectric resonators have flicker noise of frequency. What I measured was most closely related to phase noise, as opposed to Allan Deviation. Phase noise of 10811's is more consistent unit to unit than ADEV and certain more consistent than aging. BTW, ADEV at HP was measured against a special 10811 that was 500 Hz off frequency. I was never able to find out how they arrived at this golden unit. But it seems clear that it could not have been the best ever unit for ADEV, thus the real golden units that came down the pike were simply rated as ADEV too good to measure. I tried to get a project started where we would use a frequency synthesizer to do the offset. Then we could take the best units and compared them against each other. Then, as well accumulated test data, the cream would gradually rise to the top and we would have some true golden units. The problem was that there ADEV at those levels wasn't a money spec. Rick On 9/30/2012 12:16 PM, Ed Palmer wrote: Would this characteristic be similar across all 10811s or would there be as much unit to unit variation as there is for aging and Allan Deviation? Ed On 9/30/2012 11:03 AM, Richard (Rick) Karlquist wrote: I recently modified an old 10811 to bring out the crystal leads on miniature coax (instead of having them connect to the oscillator circuit). This allowed me to measure the crystal's inherent flicker noise of frequency. The measurements indicate that the 10811 phase noise out to at least 100 Hz is entirely due to the crystal. An interesting aspect of flicker noise of frequency is that Allan deviation is independent of tau. Thus, just one number describes the crystal noise. Rick On 9/30/2012 4:44 AM, Bob Camp wrote: Hi Close in, it looks like it's pretty much the crystal and the loading of the bridge oscillator. Bob On Sep 29, 2012, at 11:46 PM, Richard (Rick) Karlquist rich...@karlquist.com wrote: The E1938A uses a crystal that is basically the same as the 10811 crystal except that it is in a reduced height package. However the phase noise is not as good as a 10811 due to broadband noise in the automatic frequency control circuit. By the time I discovered this, it was too late to try to fix it. Rick Karlquist N6RK E1938A designer ___ 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] E1938A PN measurments
Bert, When you do tests like this, how long do you let the oscillators settle prior to testing? Doc Sent from my iPad On Sep 30, 2012, at 4:23 PM, ewkeh...@aol.com wrote: Rick I have some 10811's all below 1 E-12 in the 1 to 100 sec. range, a few as low as 4 E-13 at 10 seconds. How low have you seen, I have the opportunity to test 40+ units and hope to find a few even better ones. Any guidance will be appreciated. My best reference is 3 E-13 so any thing as good or better would have to be tested by some one else after initial test. Bert Kehren . In a message dated 9/30/2012 3:49:33 P.M. Eastern Daylight Time, rich...@karlquist.com writes: I only measured one 10811. However, John Vig's tutorial (available at IEEE UFFC) rather categorically states that piezoelectric resonators have flicker noise of frequency. What I measured was most closely related to phase noise, as opposed to Allan Deviation. Phase noise of 10811's is more consistent unit to unit than ADEV and certain more consistent than aging. BTW, ADEV at HP was measured against a special 10811 that was 500 Hz off frequency. I was never able to find out how they arrived at this golden unit. But it seems clear that it could not have been the best ever unit for ADEV, thus the real golden units that came down the pike were simply rated as ADEV too good to measure. I tried to get a project started where we would use a frequency synthesizer to do the offset. Then we could take the best units and compared them against each other. Then, as well accumulated test data, the cream would gradually rise to the top and we would have some true golden units. The problem was that there ADEV at those levels wasn't a money spec. Rick On 9/30/2012 12:16 PM, Ed Palmer wrote: Would this characteristic be similar across all 10811s or would there be as much unit to unit variation as there is for aging and Allan Deviation? Ed On 9/30/2012 11:03 AM, Richard (Rick) Karlquist wrote: I recently modified an old 10811 to bring out the crystal leads on miniature coax (instead of having them connect to the oscillator circuit). This allowed me to measure the crystal's inherent flicker noise of frequency. The measurements indicate that the 10811 phase noise out to at least 100 Hz is entirely due to the crystal. An interesting aspect of flicker noise of frequency is that Allan deviation is independent of tau. Thus, just one number describes the crystal noise. Rick On 9/30/2012 4:44 AM, Bob Camp wrote: Hi Close in, it looks like it's pretty much the crystal and the loading of the bridge oscillator. Bob On Sep 29, 2012, at 11:46 PM, Richard (Rick) Karlquist rich...@karlquist.com wrote: The E1938A uses a crystal that is basically the same as the 10811 crystal except that it is in a reduced height package. However the phase noise is not as good as a 10811 due to broadband noise in the automatic frequency control circuit. By the time I discovered this, it was too late to try to fix it. Rick Karlquist N6RK E1938A designer ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] E1938A PN measurments
Doc The units I mentioned have been done by Corby, but I let units run two weeks before I do any test. In the future when I do the 40+ two a week running parallel and the best rerun after 4 week soak. Bert In a message dated 9/30/2012 7:55:43 P.M. Eastern Daylight Time, docdai...@gmail.com writes: Bert, When you do tests like this, how long do you let the oscillators settle prior to testing? Doc Sent from my iPad On Sep 30, 2012, at 4:23 PM, ewkeh...@aol.com wrote: Rick I have some 10811's all below 1 E-12 in the 1 to 100 sec. range, a few as low as 4 E-13 at 10 seconds. How low have you seen, I have the opportunity to test 40+ units and hope to find a few even better ones. Any guidance will be appreciated. My best reference is 3 E-13 so any thing as good or better would have to be tested by some one else after initial test. Bert Kehren . In a message dated 9/30/2012 3:49:33 P.M. Eastern Daylight Time, rich...@karlquist.com writes: I only measured one 10811. However, John Vig's tutorial (available at IEEE UFFC) rather categorically states that piezoelectric resonators have flicker noise of frequency. What I measured was most closely related to phase noise, as opposed to Allan Deviation. Phase noise of 10811's is more consistent unit to unit than ADEV and certain more consistent than aging. BTW, ADEV at HP was measured against a special 10811 that was 500 Hz off frequency. I was never able to find out how they arrived at this golden unit. But it seems clear that it could not have been the best ever unit for ADEV, thus the real golden units that came down the pike were simply rated as ADEV too good to measure. I tried to get a project started where we would use a frequency synthesizer to do the offset. Then we could take the best units and compared them against each other. Then, as well accumulated test data, the cream would gradually rise to the top and we would have some true golden units. The problem was that there ADEV at those levels wasn't a money spec. Rick On 9/30/2012 12:16 PM, Ed Palmer wrote: Would this characteristic be similar across all 10811s or would there be as much unit to unit variation as there is for aging and Allan Deviation? Ed On 9/30/2012 11:03 AM, Richard (Rick) Karlquist wrote: I recently modified an old 10811 to bring out the crystal leads on miniature coax (instead of having them connect to the oscillator circuit). This allowed me to measure the crystal's inherent flicker noise of frequency. The measurements indicate that the 10811 phase noise out to at least 100 Hz is entirely due to the crystal. An interesting aspect of flicker noise of frequency is that Allan deviation is independent of tau. Thus, just one number describes the crystal noise. Rick On 9/30/2012 4:44 AM, Bob Camp wrote: Hi Close in, it looks like it's pretty much the crystal and the loading of the bridge oscillator. Bob On Sep 29, 2012, at 11:46 PM, Richard (Rick) Karlquist rich...@karlquist.com wrote: The E1938A uses a crystal that is basically the same as the 10811 crystal except that it is in a reduced height package. However the phase noise is not as good as a 10811 due to broadband noise in the automatic frequency control circuit. By the time I discovered this, it was too late to try to fix it. Rick Karlquist N6RK E1938A designer ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] E1938A PN measurments
On 9/30/2012 2:20 PM, Magnus Danielson wrote: With two such offset 10811s you could use DMTD methods or for that matter cross-correlation phase noise measures to more directly measure the units. That way you would have avoided the golden unit issue, since the phase noise of those would average out if treated well. Didn't you consider steps like that? I didn't own this system. Production engineering was very conservative and didn't want to change anything. 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] E1938A PN measurments
Sorry I have never seen those statistics. Rick On 9/30/2012 2:23 PM, ewkeh...@aol.com wrote: Rick I have some 10811's all below 1 E-12 in the 1 to 100 sec. range, a few as low as 4 E-13 at 10 seconds. How low have you seen, I have the opportunity to test 40+ units and hope to find a few even better ones. Any guidance will be appreciated. My best reference is 3 E-13 so any thing as good or better would have to be tested by some one else after initial test. Bert Kehren ___ 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] How are non-Trimble oscillators disciplined?
Hi, Thanks for all the good advice to get me started in this fun technology! Last weekend finished putting up the antenna that was obtained from the suggested China source, powered up a new to me Trimble Thunderbolt, obtained an old used laptop w/ DB-9 serial HW, and have been experimenting w/ the Trimble and LH software. I ran the 10Mhz signal into an HP 5087A DA to feed all the other things in the racks that accept a 10Mhz external reference, works great! One thing I am wondering about is disciplining - how much of this is HW and how much is SW? How are non-Trimble oscillators disciplined? It it common practice to provide a GPS antenna input? Is this a default in HW on some oscillator controllers, and/or is there some industry standard command set or protocol to activate disciplining? I would like to experiment with some other OCXO's, but am not sure about how they might be disciplined. Thanks and 73 Frank KJ4OLL ___ 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] E1938A PN measurments
I have a corby ocxo (datum-c) that I am coupling with a fury oem board soon (need some connectors). I wish someone with good measurement equipment lived nearby. I would like to measure this vs my standard fury. I think the ocxo is mid 10-13 at 1s. Anybody near Kansas City? Doc Sent from my iPad On Sep 30, 2012, at 7:02 PM, ewkeh...@aol.com wrote: Doc The units I mentioned have been done by Corby, but I let units run two weeks before I do any test. In the future when I do the 40+ two a week running parallel and the best rerun after 4 week soak. Bert In a message dated 9/30/2012 7:55:43 P.M. Eastern Daylight Time, docdai...@gmail.com writes: Bert, When you do tests like this, how long do you let the oscillators settle prior to testing? Doc Sent from my iPad On Sep 30, 2012, at 4:23 PM, ewkeh...@aol.com wrote: Rick I have some 10811's all below 1 E-12 in the 1 to 100 sec. range, a few as low as 4 E-13 at 10 seconds. How low have you seen, I have the opportunity to test 40+ units and hope to find a few even better ones. Any guidance will be appreciated. My best reference is 3 E-13 so any thing as good or better would have to be tested by some one else after initial test. Bert Kehren . In a message dated 9/30/2012 3:49:33 P.M. Eastern Daylight Time, rich...@karlquist.com writes: I only measured one 10811. However, John Vig's tutorial (available at IEEE UFFC) rather categorically states that piezoelectric resonators have flicker noise of frequency. What I measured was most closely related to phase noise, as opposed to Allan Deviation. Phase noise of 10811's is more consistent unit to unit than ADEV and certain more consistent than aging. BTW, ADEV at HP was measured against a special 10811 that was 500 Hz off frequency. I was never able to find out how they arrived at this golden unit. But it seems clear that it could not have been the best ever unit for ADEV, thus the real golden units that came down the pike were simply rated as ADEV too good to measure. I tried to get a project started where we would use a frequency synthesizer to do the offset. Then we could take the best units and compared them against each other. Then, as well accumulated test data, the cream would gradually rise to the top and we would have some true golden units. The problem was that there ADEV at those levels wasn't a money spec. Rick On 9/30/2012 12:16 PM, Ed Palmer wrote: Would this characteristic be similar across all 10811s or would there be as much unit to unit variation as there is for aging and Allan Deviation? Ed On 9/30/2012 11:03 AM, Richard (Rick) Karlquist wrote: I recently modified an old 10811 to bring out the crystal leads on miniature coax (instead of having them connect to the oscillator circuit). This allowed me to measure the crystal's inherent flicker noise of frequency. The measurements indicate that the 10811 phase noise out to at least 100 Hz is entirely due to the crystal. An interesting aspect of flicker noise of frequency is that Allan deviation is independent of tau. Thus, just one number describes the crystal noise. Rick On 9/30/2012 4:44 AM, Bob Camp wrote: Hi Close in, it looks like it's pretty much the crystal and the loading of the bridge oscillator. Bob On Sep 29, 2012, at 11:46 PM, Richard (Rick) Karlquist rich...@karlquist.com wrote: The E1938A uses a crystal that is basically the same as the 10811 crystal except that it is in a reduced height package. However the phase noise is not as good as a 10811 due to broadband noise in the automatic frequency control circuit. By the time I discovered this, it was too late to try to fix it. Rick Karlquist N6RK E1938A designer ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] How are non-Trimble oscillators disciplined?
I would like to experiment with some other OCXO's, but am not sure about how they might be disciplined. Almost all of them have just a just pins on their connector, ground, power (one or two voltages) and control with is a variable voltage to apply and the ooutput frequency varies over a small range that is proportional to the input voltage. The exact ratio of Hz/V is device dependance. Typically to discipline an OCXO you use a DAC to drive the control voltages. You would use a micro controller to look at some kind of phase detector and adjust the DAC. The T-Bolt is nice because all this is done for you in a low cost self contained unit. But you don't learn much that way, except how to connect cables. 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] E1938A PN measurments
On 10/01/2012 02:05 AM, Richard (Rick) Karlquist wrote: On 9/30/2012 2:20 PM, Magnus Danielson wrote: With two such offset 10811s you could use DMTD methods or for that matter cross-correlation phase noise measures to more directly measure the units. That way you would have avoided the golden unit issue, since the phase noise of those would average out if treated well. Didn't you consider steps like that? I didn't own this system. Production engineering was very conservative and didn't want to change anything. As they tend to be. But back at the engineering side at least? Anyway, setting that up today isn't rocket science, and Bert and John among others have been able to build such systems. 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] How are non-Trimble oscillators disciplined?
On 10/01/2012 02:11 AM, Frank Hughes wrote: Hi, Thanks for all the good advice to get me started in this fun technology! Last weekend finished putting up the antenna that was obtained from the suggested China source, powered up a new to me Trimble Thunderbolt, obtained an old used laptop w/ DB-9 serial HW, and have been experimenting w/ the Trimble and LH software. I ran the 10Mhz signal into an HP 5087A DA to feed all the other things in the racks that accept a 10Mhz external reference, works great! One thing I am wondering about is disciplining - how much of this is HW and how much is SW? How are non-Trimble oscillators disciplined? It it common practice to provide a GPS antenna input? You have to realize that the Thunderbolt is an amazingly open design. Just the fact that there is connectors on the PCB to hook up external oscillators makes it sane. Using a thunderbolt to control an off-board oscillator boils down to neither HW or SW details, but rather configuration details (once the oscillator is hooked up). You need to adjust the loop gain to match the EFC sensitivity of your oscillator. The loop bandwidth is another parameter to look for. Is this a default in HW on some oscillator controllers, and/or is there some industry standard command set or protocol to activate disciplining? Industry standard? I'd love to see one. Just look at the HP family of SmartClocks (Z3801A etc) and the Thunderbolt series you will realize they are different in many ways. The different design teams have taken somewhat different approaches. As long as they do that, their preferred way of doing things will differ. Learn your tool and how you can adapt it to your clocks. I would like to experiment with some other OCXO's, but am not sure about how they might be disciplined. If they have an EFC/VC input, check the voltage range and the scale of that range. It can vary a lot. Prepare to do adapter-boards doing scaling and level shifting. Toss in an offset trimmer. Using a voltage reference is highly recommended. 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] RFX GPSDO - Anybody played with one of these?
Hello Nuts, Just saw this mentioned in Circuit Cellar, just wonding if it really exists, how much they are asking, and if anyone has played with one yet? http://www.rfx.co.uk/pdfs/GPS_OCXO_1300_10_module.pdf Regards, Skip Withrow ___ 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] RFX GPSDO - Anybody played with one of these?
Offhand I can not think of any reason it could not exist but if you have to ask for the price, then I suspect it will be too expensive. On Sun, 30 Sep 2012 19:40:47 -0700, Skip Withrow skip.with...@gmail.com wrote: Hello Nuts, Just saw this mentioned in Circuit Cellar, just wonding if it really exists, how much they are asking, and if anyone has played with one yet? http://www.rfx.co.uk/pdfs/GPS_OCXO_1300_10_module.pdf Regards, Skip Withrow ___ 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.
