Re: [time-nuts] Interesting paper: Don't GPSD' your Rb...
Hi Bill, On 05/07/2012 05:12 AM, Bill Hawkins wrote: Thanks for the analysis, Magnus. Always happy to contribute. A few other time constants might be interesting - When a step change is made to the control voltage or current, how long does it take for the oscillator to settle down to a new value? Is it instantaneous compared to a second? It depends on the rubidium FLL bandwidth. For OCXO it is much quicker. Do different components in different oscillators affect the settling time? For rubidiums, yes. The FLL bandwidth will have such a lag effect until the slaved OXXO is back on track. It is not useful to make the next change before the last one is complete, at least for sampled systems. Using counters filters the change rather than taking a sample. If you flip back and forth, then it makes sense because your phase deviations will be less. You should however consider it when doing the stability analysis. 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] Interesting paper: Don't GPSD' your Rb...
Magnus, If you flip back and forth, then it makes sense because your phase deviations will be less. Can you further explain this? Thanks. On Mon, May 7, 2012 at 8:57 AM, Magnus Danielson mag...@rubidium.dyndns.org wrote: Hi Bill, On 05/07/2012 05:12 AM, Bill Hawkins wrote: Thanks for the analysis, Magnus. Always happy to contribute. A few other time constants might be interesting - When a step change is made to the control voltage or current, how long does it take for the oscillator to settle down to a new value? Is it instantaneous compared to a second? It depends on the rubidium FLL bandwidth. For OCXO it is much quicker. Do different components in different oscillators affect the settling time? For rubidiums, yes. The FLL bandwidth will have such a lag effect until the slaved OXXO is back on track. It is not useful to make the next change before the last one is complete, at least for sampled systems. Using counters filters the change rather than taking a sample. If you flip back and forth, then it makes sense because your phase deviations will be less. You should however consider it when doing the stability analysis. Cheers, Magnus __**_ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/** mailman/listinfo/time-nutshttps://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] Oh dear
I once did a test with a audio expert and compared a CD and a digital copy. He confirmed that the copy was the original and when I showed him which was which he still refused to believe.. I know a local guy who gold plated the PCBs for his home brewed amp! Raj At 07-05-2012, you wrote: These people are amazing. They refuse to do any kind of double-blind A/B testing. My favorite thing is that they are trying to extract the maximum fidelity from an album or CD that was recorded in a studio with little or no AC power conditioning, whose recording consoles were wired with the cheapest solid and stranded copper wire and whose monitor speakers were probably a pair of cheap Yamaha NS-10's (if you can make something sound good on an NS-10, it will sound good on anything). They claim to like the warm sound of their tube equipment but all they are doing is getting second-order distortion from running their tubes into a non-linear region. Tubes distort based on octaves and the distortion product is pleasant. Transistors distort on odd-order harmonics -- 3rds, 5ths, etc... And this sounds very clangerous. FETs are even order and so are often used for audiophile power amplification. The phrase Placebo Effect was coined for a reason. 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] Oh dear
On Mon, 07 May 2012 13:40:15 +0530 Raj vu2...@gmail.com wrote: I once did a test with a audio expert and compared a CD and a digital copy. He confirmed that the copy was the original and when I showed him which was which he still refused to believe.. I know a local guy who gold plated the PCBs for his home brewed amp! Well.. there is lots of bogus information going around in the audiophile scene... Probably mostly because todays audio technology is so advanced, that Clarke's 3rd Law applies... But to bring this back to time nutty topics, have a look at http://www.colorfly.eu/product.html It's an MP3 player with high precision timing. It does not only use two TCXOs with 5ps Jitter.. No! It also employes a technique known as Jitter Kill for the ultimate mobile sound experience! :-) Attila Kinali -- Why does it take years to find the answers to the questions one should have asked long ago? ___ 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] Oh dear
Let's expect the ultimate portable MP3 player with atomic clock reference... :] Also funny are the offerings with RbO CD-clocks... usually tweaked FE-5680s, which are not exactly famous for a clean jitter/spurious free output signal... The only reason is the easiness of output frequency adjustment (for the DDS models) to that of the standard CD clock, which promptly places a premium on the price tag. A good XO is way better and cheaper, with the notable exception of temperature, and long term stability - still waiting for the golden ears capable of hearing that one... On 5/7/2012 12:20 PM, Attila Kinali wrote: On Mon, 07 May 2012 13:40:15 +0530 Rajvu2...@gmail.com wrote: I once did a test with a audio expert and compared a CD and a digital copy. He confirmed that the copy was the original and when I showed him which was which he still refused to believe.. I know a local guy who gold plated the PCBs for his home brewed amp! Well.. there is lots of bogus information going around in the audiophile scene... Probably mostly because todays audio technology is so advanced, that Clarke's 3rd Law applies... But to bring this back to time nutty topics, have a look at http://www.colorfly.eu/product.html It's an MP3 player with high precision timing. It does not only use two TCXOs with5ps Jitter.. No! It also employes a technique known as Jitter Kill for the ultimate mobile sound experience! :-) 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] Oh dear
El 07/05/2012 11:20, Attila Kinali escribió: But to bring this back to time nutty topics, have a look at http://www.colorfly.eu/product.html It's an MP3 player with high precision timing. It does not only use two TCXOs with 5ps Jitter.. No! It also employes a technique known as Jitter Kill for the ultimate mobile sound experience! :-) Attila Kinali It plays MP3 or uncompressed audio? ;). And the sliding potentiotemer... prone to all kinds of noises and imbalance, and the nice wood enclosure, hand engraved, of course manufactured in a controlled temperature and humidity environment, that no doubt has a very positive effect on the sound, probably as good as the EMC shielding that provides. Also I love this paragraph On month day of year, the technique of circuit named Jitter Kill was registered as a patent for the other special technique of the Pocket HIFI player. When was/will be month day of year? excellent accuracy :) I imagine Steve Wan and his team laughing out loud everytime their get a purchase order. 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.
Re: [time-nuts] Oh dear
An old saying: a fool and his money are often parted. Sums things up nicely I feel. Rob Kimberley -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Javier Herrero Sent: 07 May 2012 11:30 To: time-nuts@febo.com Subject: Re: [time-nuts] Oh dear El 07/05/2012 11:20, Attila Kinali escribió: But to bring this back to time nutty topics, have a look at http://www.colorfly.eu/product.html It's an MP3 player with high precision timing. It does not only use two TCXOs with 5ps Jitter.. No! It also employes a technique known as Jitter Kill for the ultimate mobile sound experience! :-) Attila Kinali It plays MP3 or uncompressed audio? ;). And the sliding potentiotemer... prone to all kinds of noises and imbalance, and the nice wood enclosure, hand engraved, of course manufactured in a controlled temperature and humidity environment, that no doubt has a very positive effect on the sound, probably as good as the EMC shielding that provides. Also I love this paragraph On month day of year, the technique of circuit named Jitter Kill was registered as a patent for the other special technique of the Pocket HIFI player. When was/will be month day of year? excellent accuracy :) I imagine Steve Wan and his team laughing out loud everytime their get a purchase order. 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 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] Oh dear
How does the fool get his money? Chris Stake -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Rob Kimberley Sent: 07 May 2012 11:55 To: 'Discussion of precise time and frequency measurement' Subject: Re: [time-nuts] Oh dear An old saying: a fool and his money are often parted. Sums things up nicely I feel. Rob Kimberley -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Javier Herrero Sent: 07 May 2012 11:30 To: time-nuts@febo.com Subject: Re: [time-nuts] Oh dear El 07/05/2012 11:20, Attila Kinali escribió: But to bring this back to time nutty topics, have a look at http://www.colorfly.eu/product.html It's an MP3 player with high precision timing. It does not only use two TCXOs with 5ps Jitter.. No! It also employes a technique known as Jitter Kill for the ultimate mobile sound experience! :-) Attila Kinali It plays MP3 or uncompressed audio? ;). And the sliding potentiotemer... prone to all kinds of noises and imbalance, and the nice wood enclosure, hand engraved, of course manufactured in a controlled temperature and humidity environment, that no doubt has a very positive effect on the sound, probably as good as the EMC shielding that provides. Also I love this paragraph On month day of year, the technique of circuit named Jitter Kill was registered as a patent for the other special technique of the Pocket HIFI player. When was/will be month day of year? excellent accuracy :) I imagine Steve Wan and his team laughing out loud everytime their get a purchase order. 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 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] Oh dear
But to bring this back to time nutty topics, have a look at http://www.colorfly.eu/product.html It's an MP3 player with high precision timing. It does not only use two TCXOs with 5ps Jitter.. No! It also employes a technique known as Jitter Kill for the ultimate mobile sound experience! :-) Attila Kinali Very interesting gadget, I quote: In 1877, Edison invented a kind of recording installment which recorded 8 seconds sounds for the first time in the world. Installment ?? Raj ___ 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] Chat Room?
Time nuts has turned in to a chat room to people that have diarrhea of their fingers. The result is that many of us converse off list and do not contribute to meaningful dialog. Are there not rules and if yes, should they not be respected and adhered to? 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.
Re: [time-nuts] Chat Room?
Hi Bert, Couldn't agree more with you. On the other hand, and which is even worse, questions from not-so-hardcore-time-nuts are simply ignored on a random basis. I'm leaving the group. If you ever come to or need something from Spain, let me know. Regards, Roberto EB4EQA -Original Message- From: ewkeh...@aol.com Sent: Monday, May 07, 2012 2:15 PM To: time-nuts@febo.com Subject: [time-nuts] Chat Room? Time nuts has turned in to a chat room to people that have diarrhea of their fingers. The result is that many of us converse off list and do not contribute to meaningful dialog. Are there not rules and if yes, should they not be respected and adhered to? 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 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] Chat Room?
amen -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of ewkeh...@aol.com Sent: Monday, May 07, 2012 7:15 AM To: time-nuts@febo.com Subject: [time-nuts] Chat Room? Time nuts has turned in to a chat room to people that have diarrhea of their fingers. The result is that many of us converse off list and do not contribute to meaningful dialog. Are there not rules and if yes, should they not be respected and adhered to? 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 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] Chat Room?
I've not seen many questions ignored on this excellent group. If they were, then maybe, just maybe no one had an answer at that time. Rob Kimberley -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Roberto Barrios Sent: 07 May 2012 14:18 To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Chat Room? Hi Bert, Couldn't agree more with you. On the other hand, and which is even worse, questions from not-so-hardcore-time-nuts are simply ignored on a random basis. I'm leaving the group. If you ever come to or need something from Spain, let me know. Regards, Roberto EB4EQA -Original Message- From: ewkeh...@aol.com Sent: Monday, May 07, 2012 2:15 PM To: time-nuts@febo.com Subject: [time-nuts] Chat Room? Time nuts has turned in to a chat room to people that have diarrhea of their fingers. The result is that many of us converse off list and do not contribute to meaningful dialog. Are there not rules and if yes, should they not be respected and adhered to? 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 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] Chat Room?
Yes, that is the case: if I have no clue than simply I don't write nothing... Roberto, please, if you have any question, try now. I'm here. You were trying to set up a lock identifier for the XOR type FLL. I suggested a simple count the difference method: an UP-DOWN counter tied to the two 10KHz (Jupiter GPS and OCXO-derived). On Mon, May 7, 2012 at 3:40 PM, Rob Kimberley robkimber...@btinternet.comwrote: I've not seen many questions ignored on this excellent group. If they were, then maybe, just maybe no one had an answer at that time. Rob Kimberley -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Roberto Barrios Sent: 07 May 2012 14:18 To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Chat Room? Hi Bert, Couldn't agree more with you. On the other hand, and which is even worse, questions from not-so-hardcore-time-nuts are simply ignored on a random basis. I'm leaving the group. If you ever come to or need something from Spain, let me know. Regards, Roberto EB4EQA -Original Message- From: ewkeh...@aol.com Sent: Monday, May 07, 2012 2:15 PM To: time-nuts@febo.com Subject: [time-nuts] Chat Room? Time nuts has turned in to a chat room to people that have diarrhea of their fingers. The result is that many of us converse off list and do not contribute to meaningful dialog. Are there not rules and if yes, should they not be respected and adhered to? 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 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] Chat Room?
I suggest that the kind of techno-eliteism displayed in these comment, in fact, breeds the kind of drivel in that eBay ad. An average reader is simply not equipped to deal with piles of BS, whether it is about Rubidiums and sampling rate stability or phase noise or Adev and LadyHeather. YMMV, -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.
[time-nuts] Oh dear
A friend of mine signed me up for a catalog from the Audio Advisor. He said I deserved this - I was afraid to ask what he meant by that! Spend a few minutes looking over this site: http://www.audioadvisor.com/ Be sure to check out their Power cords at: http://home-audio.audioadvisor.com/search?w=Power+Cords Burt, K6OQK From: Rob Kimberley robkimber...@btinternet.com To: 'Discussion of precise time and frequency measurement' time-nuts@febo.com Subject: Re: [time-nuts] Oh dear An old saying: a fool and his money are often parted. Sums things up nicely I feel. Rob Kimberley Burt I. Weiner Associates Broadcast Technical Services Glendale, California U.S.A. b...@att.net www.biwa.cc K6OQK ___ 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] Oh dear
I must get one of their line cords to see if it will improve my timing system!! You just have to laugh at this nonsense. Rob K -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Burt I. Weiner Sent: 07 May 2012 15:39 To: time-nuts@febo.com Subject: [time-nuts] Oh dear A friend of mine signed me up for a catalog from the Audio Advisor. He said I deserved this - I was afraid to ask what he meant by that! Spend a few minutes looking over this site: http://www.audioadvisor.com/ Be sure to check out their Power cords at: http://home-audio.audioadvisor.com/search?w=Power+Cords Burt, K6OQK From: Rob Kimberley robkimber...@btinternet.com To: 'Discussion of precise time and frequency measurement' time-nuts@febo.com Subject: Re: [time-nuts] Oh dear An old saying: a fool and his money are often parted. Sums things up nicely I feel. Rob Kimberley Burt I. Weiner Associates Broadcast Technical Services Glendale, California U.S.A. b...@att.net www.biwa.cc K6OQK ___ 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] Oh dear
In message 226574.14407...@smtp104.sbc.mail.mud.yahoo.com, Burt I. Weiner w rites: Be sure to check out their Power cords at: http://home-audio.audioadvisor.com/search?w=Power+Cords I always wondered how the distortion could stop right at the power outlet, but I see that somebody has cornered that market now. Next step will be to try to sell them electricity produced on turbogenerators aligned to the earths magnetic field in order to deliver minimal low unharmonic distotion... -- 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] Oh dear
Nope. Any Audiophool knows green electricity sounds much better, without any artifacts produced by those annoying carbon atoms in coal, oil, or natural gas, rattling around producing annoying distractions. -John In message 226574.14407...@smtp104.sbc.mail.mud.yahoo.com, Burt I. Weiner w rites: Be sure to check out their Power cords at: http://home-audio.audioadvisor.com/search?w=Power+Cords I always wondered how the distortion could stop right at the power outlet, but I see that somebody has cornered that market now. Next step will be to try to sell them electricity produced on turbogenerators aligned to the earths magnetic field in order to deliver minimal low unharmonic distotion... -- 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] Oh dear
On 5/7/12 7:39 AM, Burt I. Weiner wrote: A friend of mine signed me up for a catalog from the Audio Advisor. He said I deserved this - I was afraid to ask what he meant by that! Spend a few minutes looking over this site: http://www.audioadvisor.com/ Be sure to check out their Power cords at: http://home-audio.audioadvisor.com/search?w=Power+Cords Burt, K6OQK Well.. this is where folks on this list can do the world a service.. The whole thing about timing, stability, phase noise, Allan deviations, etc. *is* complex, and it's tricky to come up with easy to understand, short, descriptions of why using a Rb for your CD player is BS. We've all had to learn this stuff, and we do it in different ways, so maybe the collective hive-mind is a good way to come up with decent responses (after the initial wave of can you believe it) It's like explaining RF exposure limits. There's a certain amount of physics you have to know in order to understand how the limits work. Most people do understand what's BS and what's not, once they understand why. - the recent GPS filtering thing.. it took a YEAR for someone in the PNT community to finally come up with a good, simple explanation of why L^2 arguments were invalid. And it comes down to the fact that GPS isn't a communication link, so you can't use that conceptual model to analyze it. Once you get that, then people go oh! That's why we can't do that and have it still work And, on a more technically sophisticated level, there's lots of engineers who are still wrapping their heads around the duality of time domain (ADEV) and frequency domain (Phase noise) measurements, and when you might use one or the other. I've found a lot of good stuff on this list for explaining it (and improving my own understanding.. nothing like needing to explain it to someone else to test your own conceptual understanding) Interestingly, setting someone up with a counter, timelab, and a not so hot function generator and letting them record and play for a couple days (or over the weekend) is a great way. You see things like diurnal variation, the HVAC cycling on and off, the sun shining through the window. The spectrum analyzer does the phase noise thing fairly well (although not for close in), and concepts like reciprocal mixing from a noisy LO gunking up your narrow band signal are pretty obvious. After that it's practical applications.. Just how bad can the noise be for a particular application? Are you interested in integrated jitter? ___ 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] Oh dear
And for those who want a good debunking article to show to their non-technical friends: http://www.audioholics.com/education/cables/power-cables On 5/7/2012 8:01 AM, Poul-Henning Kamp wrote: In message226574.14407...@smtp104.sbc.mail.mud.yahoo.com, Burt I. Weiner w rites: Be sure to check out their Power cords at: http://home-audio.audioadvisor.com/search?w=Power+Cords I always wondered how the distortion could stop right at the power outlet, but I see that somebody has cornered that market now. Next step will be to try to sell them electricity produced on turbogenerators aligned to the earths magnetic field in order to deliver minimal low unharmonic distotion... ___ 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] Oh dear
In message 52252.12.6.201.2.1336403114.squir...@popaccts.quikus.com, J. Fors ter writes: Any Audiophool knows green electricity sounds much better, without any artifacts produced by those annoying carbon atoms in coal, oil, or natural gas, rattling around producing annoying distractions. Unless, of course, you burn pure diamonds... -- 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] Oh dear
All this kerfuffle about that Rubidium Clock kind of misses the point. This is not some Audiophool thing but a serious piece of gear used for recording studios. I am not going to get into the pricing of it, but if you add up the cost of a /new/ Rb unit, distribution amp, power supply and back up batteries built into a case, it starts to add up. I see nothing odd about wanting to get the best possible source for the Master Clock for your master recordings. My son does run a small studio and for him I was able to make a version of that unit, for a lot less money of course. If he says it improves the sound of the recordings, and his customers agree, I am inclined to believe him. What could be more time nuts than wanting a precise clock? Dan ___ 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] Oh dear
In message 4fa7e639.9090...@earthlink.net, Jim Lux writes: Well.. this is where folks on this list can do the world a service.. The whole thing about timing, stability, phase noise, Allan deviations, etc. *is* complex, and it's tricky to come up with easy to understand, short, descriptions of why using a Rb for your CD player is BS. You seem to be working under the assumption that they care about the measurable reality. They do not. This is about bling and about being better than the brother-in-law at something, it has nothing to do with sound. -- 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] Chat Room?
Roberto you and I have already dialog off list that I value and we will continue. Some legitimate questions get drowned out by off subject postings but in my opinion there is room for techno elitism on subjects that are time and frequency related I have learned a lot, and for time/frequency elitism, time nuts is the place. I was referring to chatter that is not in any way time or frequency related. Bert Kehren In a message dated 5/7/2012 9:38:20 A.M. Eastern Daylight Time, rbarri...@msn.com writes: Hi Bert, Couldn't agree more with you. On the other hand, and which is even worse, questions from not-so-hardcore-time-nuts are simply ignored on a random basis. I'm leaving the group. If you ever come to or need something from Spain, let me know. Regards, Roberto EB4EQA -Original Message- From: ewkeh...@aol.com Sent: Monday, May 07, 2012 2:15 PM To: time-nuts@febo.com Subject: [time-nuts] Chat Room? Time nuts has turned in to a chat room to people that have diarrhea of their fingers. The result is that many of us converse off list and do not contribute to meaningful dialog. Are there not rules and if yes, should they not be respected and adhered to? 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 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] Oh dear
This is the most ridiculous discussion in the history of this group. If anyone could sympathize with the need for super-timing on audio it should be those of you who think you need cesium clocks in your homes. -RL --- Robert Lutwak | SymmetricomR, Inc. Chief Scientist -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Burt I. Weiner Sent: Monday, May 07, 2012 10:39 AM To: time-nuts@febo.com Subject: [time-nuts] Oh dear A friend of mine signed me up for a catalog from the Audio Advisor. He said I deserved this - I was afraid to ask what he meant by that! Spend a few minutes looking over this site: http://www.audioadvisor.com/ Be sure to check out their Power cords at: http://home-audio.audioadvisor.com/search?w=Power+Cords Burt, K6OQK From: Rob Kimberley robkimber...@btinternet.com To: 'Discussion of precise time and frequency measurement' time-nuts@febo.com Subject: Re: [time-nuts] Oh dear An old saying: a fool and his money are often parted. Sums things up nicely I feel. Rob Kimberley Burt I. Weiner Associates Broadcast Technical Services Glendale, California U.S.A. b...@att.net www.biwa.cc K6OQK ___ 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] DPLL for 10MHz
Does anyone have any knowledge of a simple (just soldering a few connections and maybe programming a hz/volt rate) PCB for synchronizing a precision OCXO to a GPSDO? I am trying to improve short term stability with a high stability OCXO and dont want to cut into my fury and replace the OCXO. I cando it manually but this seems like it would be nice and desirable for many yet I can't find anything. I presume it would have to be digital because of the long time constant. Doc KX0O Sent from my iPhone ___ 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] Oh dear
As an Audiophile and T-Nut I am often torn by what could affect sound quality, but I have realized that there are many things that affect sound that as engineers we have not learned to define. As a scientist I look forward to the day we can accurately rate how equipment will sound in mathematical terms. I fact in the next month I will be working on a project that covers both my Time Nut and Audio passions with one of the music industries leading engineers Gus Skinas who has lead the development of the SACD. Jitter is a concern in digital audio and we are going to use a Cesium standard and low phase noise clean-up oscillator during recording and playback to determine the degree that timing affects sound quality. I am still not ready to spent thousands on power cords. Thomas Knox From: robkimber...@btinternet.com To: time-nuts@febo.com Date: Mon, 7 May 2012 15:55:15 +0100 Subject: Re: [time-nuts] Oh dear I must get one of their line cords to see if it will improve my timing system!! You just have to laugh at this nonsense. Rob K -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Burt I. Weiner Sent: 07 May 2012 15:39 To: time-nuts@febo.com Subject: [time-nuts] Oh dear A friend of mine signed me up for a catalog from the Audio Advisor. He said I deserved this - I was afraid to ask what he meant by that! Spend a few minutes looking over this site: http://www.audioadvisor.com/ Be sure to check out their Power cords at: http://home-audio.audioadvisor.com/search?w=Power+Cords Burt, K6OQK From: Rob Kimberley robkimber...@btinternet.com To: 'Discussion of precise time and frequency measurement' time-nuts@febo.com Subject: Re: [time-nuts] Oh dear An old saying: a fool and his money are often parted. Sums things up nicely I feel. Rob Kimberley Burt I. Weiner Associates Broadcast Technical Services Glendale, California U.S.A. b...@att.net www.biwa.cc K6OQK ___ 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] Oh dear
A crummy crystal oscillator zero beated to WWV is good to 1 in 10E6, a Rb disciplined to GPS maybe 1 in 10E11. Do you seriously think you, or anybody, can hear a pitch difference of 0.001 Hz in the audio range? A quartz crystal is plenty good for any audio application, IMO. -John = All this kerfuffle about that Rubidium Clock kind of misses the point. This is not some Audiophool thing but a serious piece of gear used for recording studios. I am not going to get into the pricing of it, but if you add up the cost of a /new/ Rb unit, distribution amp, power supply and back up batteries built into a case, it starts to add up. I see nothing odd about wanting to get the best possible source for the Master Clock for your master recordings. My son does run a small studio and for him I was able to make a version of that unit, for a lot less money of course. If he says it improves the sound of the recordings, and his customers agree, I am inclined to believe him. What could be more time nuts than wanting a precise clock? Dan ___ 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] DPLL for 10MHz
In message 063ae10c-af96-4f39-9caf-9e5ecc96b...@gmail.com, Bill Dailey writes : Does anyone have any knowledge of a simple (just soldering a few connections and maybe programming a hz/volt rate) PCB for synchronizing a precision OCXO to a GPSDO? I am trying to improve short term stability with a high stability OCXO and dont want to cut into my fury and replace the OCXO. The Vectron TRU-50 is pretty good for that. -- 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] Oh dear
In message 226574.14407...@smtp104.sbc.mail.mud.yahoo.com, Burt I. Weiner w rites: Next step will be to try to sell them electricity produced on turbogenerators aligned to the earths magnetic field in order to deliver minimal low unharmonic distotion... I've been thinking I should be selling motor/generators to this idiots. Basically it is just an AC alternator that is belt driven by an electric motor. It produces very clean power as there is no electrical connection to the grid. The rubber belt is non-conductive. It is useless and not needed but at least uses real science and works as advertised. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 Not to try and one up you or anything but... I remember using 7th ed on a Vax780. It was a novelty we had no real use for it. Must have beed about the time timeframe as your Zilog machine. 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] Chat Room?
Time nuts has turned in to a chat room to people that have diarrhea of their fingers. The result is that many of us converse off list and do not contribute to meaningful dialog. Are there not rules and if yes, should they not be respected and adhered to? Bert Kehren Bert, The guidelines, if any: http://leapsecond.com/time-nuts.htm My original intent for the group was that postings be the result of some level of research, experiment, or significant experience. The group has wide and deep interests and experiences; it's a learning opportunity for all of us when this is shared. But it needs to stay on topic to work. At times we moderate the postings but this is very time intensive so mostly we just rely on everyone's restraint to keep the list on topic. It seems the larger problem is not so much the occasional OT posting but the meteor shower of shallow replies that follow. If any of you have suggestions on how to improve the list send me an email, off-line: t...@leapsecond.com /tvb ___ 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] DPLL for 10MHz
Doc contact me off list Bert Kehren In a message dated 5/7/2012 11:40:04 A.M. Eastern Daylight Time, docdai...@gmail.com writes: Does anyone have any knowledge of a simple (just soldering a few connections and maybe programming a hz/volt rate) PCB for synchronizing a precision OCXO to a GPSDO? I am trying to improve short term stability with a high stability OCXO and dont want to cut into my fury and replace the OCXO. I cando it manually but this seems like it would be nice and desirable for many yet I can't find anything. I presume it would have to be digital because of the long time constant. Doc KX0O Sent from my iPhone ___ 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] Oh dear
On Mon, 07 May 2012 08:20:55 -0700 Dan Rae dan...@verizon.net wrote: I see nothing odd about wanting to get the best possible source for the Master Clock for your master recordings. My son does run a small studio and for him I was able to make a version of that unit, for a lot less money of course. If he says it improves the sound of the recordings, and his customers agree, I am inclined to believe him. The thing is, that an Rb is good for one thing: Have a long term stable and accurate frequency source that is better than 1 to some billions for measurement or other stuff that take more than a few hours or have to be repeated exactly in a couple of weeks. For audio, you need a frequency source that is stable over a couple of hours (probably a working day) and shows low jitter. Where as low jitter is quite high in time-nuts terms and stable not stable at all. A cycle-to-cylcle jitter of a couple of ns is not audioable at all, but any Rb will have a much lower jitter. Or to have a different look at it, you want to have very low phase noise, as this phase noise is mixed in over the ADCs into your signal. But as we know, the phase noise of an Rb is not defined by the Rb physics package, but by the OCXO they use. (yes i know that the close in phase noise is defined by the reference and not by the OCXO, but the base level is the OCXO, not the reference) As for stability. You want the instruments to sound the same over an recording. Ie the human ear has to preceive the recorded sound as the same. The frequency resolution of the human ear is somewhere around 3Hz. This makes for 150ppm (at 20kHz). Even a 32kHz tuning fork crystal achieves an absolute accuracy that is better than this. Its stability is much better than this Of course, you want to have enought headroom for other non ideal components. So, lets say, go for a factor of 10, then we are at 15ppm. For absolute accuracy, that's already a good XO. For stability, still most XO should do that. Or to say it differently: Using some good OCXO with low or very low phase noise would be more than enough for even the most high end audio equipment. You don't even have to discipline it, as a even quite bad OCXO has variations much lower than 1ppm, which is definitly not something anyone can hear. IMHO getting a 20-50USD OCXO from ebay, some good, low noise power supply (audio power supplies with low noise in the 40kHz region), some distribution amplifier with low noise figure and you are set. All in all probably at a cost of 200-300USD including rack mount. If you want to have high fidelity you can use an GPSDO to get your OCXO within a couple mHz. To summarize: Nobody here does want to insult anyone who does professional audio recordings. But having the knowledge of what the stability and accuracy numbers for an ordinary Rb mean, and being able to put that into perspective with the not so good capabilties of the human sensory systems, one wonders why people spend an awfull lot of money for something that has no audiable effect over something a lot cheaper. Not to mention that other things have a much higher impact on audio quality than the reference oscillator: Like temperature and humidity during recording (do you control them as well to the ppm level?), or the tuning of the instruments which wanders quite a bit during use. Attila Kinali -- Why does it take years to find the answers to the questions one should have asked long ago? ___ 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] DPLL for 10MHz
This is something I would also like to know. I'm sure many others would be interested as well. Bert would it be possible for you to share your thoughts on the matter with the group at large? -Eric On Mon, May 7, 2012 at 8:43 AM, ewkeh...@aol.com wrote: Doc contact me off list Bert Kehren In a message dated 5/7/2012 11:40:04 A.M. Eastern Daylight Time, docdai...@gmail.com writes: Does anyone have any knowledge of a simple (just soldering a few connections and maybe programming a hz/volt rate) PCB for synchronizing a precision OCXO to a GPSDO? I am trying to improve short term stability with a high stability OCXO and dont want to cut into my fury and replace the OCXO. I cando it manually but this seems like it would be nice and desirable for many yet I can't find anything. I presume it would have to be digital because of the long time constant. Doc KX0O Sent from my iPhone ___ 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. -- --Eric _ Eric Garner ___ 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] Oh dear
Actually the numbers are quite real, play with the math, a small amount of jitter in a DAC (X) can have a large difference (Y) when sampling a complex wave form especially in the audiophile world where the sound of 24bit dac 16,777,216 discrete levels is clearly superior to older 16 bit dac 65,536 possible levels in 44.1 KHz to 192 KHz formats. Thomas Knox Date: Mon, 7 May 2012 17:59:04 +0200 From: att...@kinali.ch To: time-nuts@febo.com Subject: Re: [time-nuts] Oh dear On Mon, 07 May 2012 08:20:55 -0700 Dan Rae dan...@verizon.net wrote: I see nothing odd about wanting to get the best possible source for the Master Clock for your master recordings. My son does run a small studio and for him I was able to make a version of that unit, for a lot less money of course. If he says it improves the sound of the recordings, and his customers agree, I am inclined to believe him. The thing is, that an Rb is good for one thing: Have a long term stable and accurate frequency source that is better than 1 to some billions for measurement or other stuff that take more than a few hours or have to be repeated exactly in a couple of weeks. For audio, you need a frequency source that is stable over a couple of hours (probably a working day) and shows low jitter. Where as low jitter is quite high in time-nuts terms and stable not stable at all. A cycle-to-cylcle jitter of a couple of ns is not audioable at all, but any Rb will have a much lower jitter. Or to have a different look at it, you want to have very low phase noise, as this phase noise is mixed in over the ADCs into your signal. But as we know, the phase noise of an Rb is not defined by the Rb physics package, but by the OCXO they use. (yes i know that the close in phase noise is defined by the reference and not by the OCXO, but the base level is the OCXO, not the reference) As for stability. You want the instruments to sound the same over an recording. Ie the human ear has to preceive the recorded sound as the same. The frequency resolution of the human ear is somewhere around 3Hz. This makes for 150ppm (at 20kHz). Even a 32kHz tuning fork crystal achieves an absolute accuracy that is better than this. Its stability is much better than this Of course, you want to have enought headroom for other non ideal components. So, lets say, go for a factor of 10, then we are at 15ppm. For absolute accuracy, that's already a good XO. For stability, still most XO should do that. Or to say it differently: Using some good OCXO with low or very low phase noise would be more than enough for even the most high end audio equipment. You don't even have to discipline it, as a even quite bad OCXO has variations much lower than 1ppm, which is definitly not something anyone can hear. IMHO getting a 20-50USD OCXO from ebay, some good, low noise power supply (audio power supplies with low noise in the 40kHz region), some distribution amplifier with low noise figure and you are set. All in all probably at a cost of 200-300USD including rack mount. If you want to have high fidelity you can use an GPSDO to get your OCXO within a couple mHz. To summarize: Nobody here does want to insult anyone who does professional audio recordings. But having the knowledge of what the stability and accuracy numbers for an ordinary Rb mean, and being able to put that into perspective with the not so good capabilties of the human sensory systems, one wonders why people spend an awfull lot of money for something that has no audiable effect over something a lot cheaper. Not to mention that other things have a much higher impact on audio quality than the reference oscillator: Like temperature and humidity during recording (do you control them as well to the ppm level?), or the tuning of the instruments which wanders quite a bit during use. Attila Kinali -- Why does it take years to find the answers to the questions one should have asked long ago? ___ 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] DPLL for 10MHz
On Mon, 07 May 2012 15:34:21 +, Poul-Henning Kamp p...@phk.freebsd.dk wrote: In message 063ae10c-af96-4f39-9caf-9e5ecc96b...@gmail.com, Bill Dailey writes : Does anyone have any knowledge of a simple (just soldering a few connections and maybe programming a hz/volt rate) PCB for synchronizing a precision OCXO to a GPSDO? I am trying to improve short term stability with a high stability OCXO and dont want to cut into my fury and replace the OCXO. The Vectron TRU-50 is pretty good for that. That is an interesting part but what is the price and availability? It looks suspiciously like if you have to ask, then you can not afford it. ___ 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] Oh dear
Actually in digital audio playback timing is just as important except that there is no was to remove jitter during poor recordings. Thomas Knox Date: Mon, 7 May 2012 08:20:55 -0700 From: dan...@verizon.net To: time-nuts@febo.com Subject: Re: [time-nuts] Oh dear All this kerfuffle about that Rubidium Clock kind of misses the point. This is not some Audiophool thing but a serious piece of gear used for recording studios. I am not going to get into the pricing of it, but if you add up the cost of a /new/ Rb unit, distribution amp, power supply and back up batteries built into a case, it starts to add up. I see nothing odd about wanting to get the best possible source for the Master Clock for your master recordings. My son does run a small studio and for him I was able to make a version of that unit, for a lot less money of course. If he says it improves the sound of the recordings, and his customers agree, I am inclined to believe him. What could be more time nuts than wanting a precise clock? Dan ___ 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] Oh dear
On Mon, 7 May 2012 10:02:25 -0600 Tom Knox act...@hotmail.com wrote: Actually the numbers are quite real, play with the math, a small amount of jitter in a DAC (X) can have a large difference (Y) when sampling a complex wave form especially in the audiophile world where the sound of 24bit dac 16,777,216 discrete levels is clearly superior to older 16 bit dac 65,536 possible levels in 44.1 KHz to 192 KHz formats. Yes, i know that jitter is a pain when it comes to ADCs, but keep in mind that your audio ADC does have a jitter of a couple 100ps itself. If it's a high end ADC that is. The standard ADCs are usually in the ns range. For a normal 10MHz XO you measure the jitter in in the lower 10ps at most, a good one at lower than 1ps cycle-to-cycle. Of course, you have to keep the clock signal clean of any disturbance that might add modulations to it. But that's a matter of keeping the power supply clean and having the signal shielded. It's not an inherent property of an Rb to have low jitter. And as we all know from the recent hype on the FE-5860As and the following measurements, not all Rb's are low jitter. Attila Kinali -- Why does it take years to find the answers to the questions one should have asked long ago? ___ 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] DPLL for 10MHz
Tried, no interest, some one has offered to in the future do a gate array version, you may want to wait for that I am in the mean time using am analog loop for less than 100 seconds between Rb and OCXO and a very modified Shera for GPS/Rb. Works for me. Contact me off list and we can talk. Bert In a message dated 5/7/2012 12:05:54 P.M. Eastern Daylight Time, garn...@gmail.com writes: This is something I would also like to know. I'm sure many others would be interested as well. Bert would it be possible for you to share your thoughts on the matter with the group at large? -Eric On Mon, May 7, 2012 at 8:43 AM, ewkeh...@aol.com wrote: Doc contact me off list Bert Kehren In a message dated 5/7/2012 11:40:04 A.M. Eastern Daylight Time, docdai...@gmail.com writes: Does anyone have any knowledge of a simple (just soldering a few connections and maybe programming a hz/volt rate) PCB for synchronizing a precision OCXO to a GPSDO? I am trying to improve short term stability with a high stability OCXO and dont want to cut into my fury and replace the OCXO. I cando it manually but this seems like it would be nice and desirable for many yet I can't find anything. I presume it would have to be digital because of the long time constant. Doc KX0O Sent from my iPhone ___ 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. -- --Eric _ Eric Garner ___ 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] Oh dear
On Mon, 7 May 2012 18:19:19 +0200 Attila Kinali att...@kinali.ch wrote: Of course, you have to keep the clock signal clean of any disturbance that might add modulations to it. But that's a matter of keeping the power supply clean and having the signal shielded. It's not an inherent property of an Rb to have low jitter. And as we all know from the recent hype on the FE-5860As and the following measurements, not all Rb's are low jitter. Addendum: Just to make sure it doesn't sound like i think that engineering audio devices is easy. Dealing with audioable frequencies is probably one of the most tedious tasks you can give to an electrical engineer these days. You have to deal with very low frequencies and you are not allowed to do averaging... Attila Kinali -- Why does it take years to find the answers to the questions one should have asked long ago? ___ 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] DPLL for 10MHz
Using the PPS as a sync source? On Mon, May 7, 2012 at 6:24 PM, ewkeh...@aol.com wrote: Tried, no interest, some one has offered to in the future do a gate array version, you may want to wait for that I am in the mean time using am analog loop for less than 100 seconds between Rb and OCXO and a very modified Shera for GPS/Rb. Works for me. Contact me off list and we can talk. Bert In a message dated 5/7/2012 12:05:54 P.M. Eastern Daylight Time, garn...@gmail.com writes: This is something I would also like to know. I'm sure many others would be interested as well. Bert would it be possible for you to share your thoughts on the matter with the group at large? -Eric On Mon, May 7, 2012 at 8:43 AM, ewkeh...@aol.com wrote: Doc contact me off list Bert Kehren In a message dated 5/7/2012 11:40:04 A.M. Eastern Daylight Time, docdai...@gmail.com writes: Does anyone have any knowledge of a simple (just soldering a few connections and maybe programming a hz/volt rate) PCB for synchronizing a precision OCXO to a GPSDO? I am trying to improve short term stability with a high stability OCXO and dont want to cut into my fury and replace the OCXO. I cando it manually but this seems like it would be nice and desirable for many yet I can't find anything. I presume it would have to be digital because of the long time constant. Doc KX0O Sent from my iPhone ___ 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. -- --Eric _ Eric Garner ___ 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] DPLL for 10MHz
The Vectron TRU-050 is a PLL with an integrated VCXO. You can sync a 10MHz OCXO but not from a GPS receiver with the PPS only. On Mon, May 7, 2012 at 6:29 PM, Azelio Boriani azelio.bori...@screen.itwrote: Using the PPS as a sync source? On Mon, May 7, 2012 at 6:24 PM, ewkeh...@aol.com wrote: Tried, no interest, some one has offered to in the future do a gate array version, you may want to wait for that I am in the mean time using am analog loop for less than 100 seconds between Rb and OCXO and a very modified Shera for GPS/Rb. Works for me. Contact me off list and we can talk. Bert In a message dated 5/7/2012 12:05:54 P.M. Eastern Daylight Time, garn...@gmail.com writes: This is something I would also like to know. I'm sure many others would be interested as well. Bert would it be possible for you to share your thoughts on the matter with the group at large? -Eric On Mon, May 7, 2012 at 8:43 AM, ewkeh...@aol.com wrote: Doc contact me off list Bert Kehren In a message dated 5/7/2012 11:40:04 A.M. Eastern Daylight Time, docdai...@gmail.com writes: Does anyone have any knowledge of a simple (just soldering a few connections and maybe programming a hz/volt rate) PCB for synchronizing a precision OCXO to a GPSDO? I am trying to improve short term stability with a high stability OCXO and dont want to cut into my fury and replace the OCXO. I cando it manually but this seems like it would be nice and desirable for many yet I can't find anything. I presume it would have to be digital because of the long time constant. Doc KX0O Sent from my iPhone ___ 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. -- --Eric _ Eric Garner ___ 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] Oh dear
If you take into consideration that the best currently available DACs, also true for analog circuits, have a dynamic range about 120-126dB, the last 3-4 bits are quite irrelevant (random noise mostly)... a good 20bit DAC already pushes the limits. The marketingdroids swarming for the newest 32 bitters is even more ludicrous. On the other side, the dynamic range of the ear (if you care the least for the future of your hearing), and of the quietest available listening spaces, hardly gets to 100dB... Of course, for the DSPs involved in the signal chain, 32bits integer math might not be enough, due to rounding errors. On 5/7/2012 7:02 PM, Tom Knox wrote: Actually the numbers are quite real, play with the math, a small amount of jitter in a DAC (X) can have a large difference (Y) when sampling a complex wave form especially in the audiophile world where the sound of 24bit dac 16,777,216 discrete levels is clearly superior to older 16 bit dac 65,536 possible levels in 44.1 KHz to 192 KHz formats. Thomas Knox Date: Mon, 7 May 2012 17:59:04 +0200 From: att...@kinali.ch To: time-nuts@febo.com Subject: Re: [time-nuts] Oh dear On Mon, 07 May 2012 08:20:55 -0700 Dan Raedan...@verizon.net wrote: I see nothing odd about wanting to get the best possible source for the Master Clock for your master recordings. My son does run a small studio and for him I was able to make a version of that unit, for a lot less money of course. If he says it improves the sound of the recordings, and his customers agree, I am inclined to believe him. The thing is, that an Rb is good for one thing: Have a long term stable and accurate frequency source that is better than 1 to some billions for measurement or other stuff that take more than a few hours or have to be repeated exactly in a couple of weeks. For audio, you need a frequency source that is stable over a couple of hours (probably a working day) and shows low jitter. Where as low jitter is quite high in time-nuts terms and stable not stable at all. A cycle-to-cylcle jitter of a couple of ns is not audioable at all, but any Rb will have a much lower jitter. Or to have a different look at it, you want to have very low phase noise, as this phase noise is mixed in over the ADCs into your signal. But as we know, the phase noise of an Rb is not defined by the Rb physics package, but by the OCXO they use. (yes i know that the close in phase noise is defined by the reference and not by the OCXO, but the base level is the OCXO, not the reference) As for stability. You want the instruments to sound the same over an recording. Ie the human ear has to preceive the recorded sound as the same. The frequency resolution of the human ear is somewhere around 3Hz. This makes for 150ppm (at 20kHz). Even a 32kHz tuning fork crystal achieves an absolute accuracy that is better than this. Its stability is much better than this Of course, you want to have enought headroom for other non ideal components. So, lets say, go for a factor of 10, then we are at 15ppm. For absolute accuracy, that's already a good XO. For stability, still most XO should do that. Or to say it differently: Using some good OCXO with low or very low phase noise would be more than enough for even the most high end audio equipment. You don't even have to discipline it, as a even quite bad OCXO has variations much lower than 1ppm, which is definitly not something anyone can hear. IMHO getting a 20-50USD OCXO from ebay, some good, low noise power supply (audio power supplies with low noise in the40kHz region), some distribution amplifier with low noise figure and you are set. All in all probably at a cost of 200-300USD including rack mount. If you want to have high fidelity you can use an GPSDO to get your OCXO within a couple mHz. To summarize: Nobody here does want to insult anyone who does professional audio recordings. But having the knowledge of what the stability and accuracy numbers for an ordinary Rb mean, and being able to put that into perspective with the not so good capabilties of the human sensory systems, one wonders why people spend an awfull lot of money for something that has no audiable effect over something a lot cheaper. Not to mention that other things have a much higher impact on audio quality than the reference oscillator: Like temperature and humidity during recording (do you control them as well to the ppm level?), or the tuning of the instruments which wanders quite a bit during use. Attila Kinali -- Why does it take years to find the answers to the questions one should have asked long ago? ___ 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,
Re: [time-nuts] Oh dear
It has nothing to do with engineering. Artists, and I use the word with a huge bag of salt, are often Prima Donnas. They are under the illusion that their works are masterpieces, because they sell millions of copies on iTunes or elsewhere, or theit concerts are sold out in two minutes. So, naturally, every nuance of their work needs THE most elaborate equipment to reproduce it in every breathless detail. So, to cater to the talent, studios build bigger, more impressive, facilities, to attract them. It's almost entirely a marketing enterprise. The hucksters leading the gullible at all levels. I have a friend who is very into classical music. He spent tens of thousands on a sound system. I then suggested he spend a few hundred and go listen to the Boston Symphony live and in person. He was really bummed out for months afterwards. Now he has taken up collecting records, yes vinyl. Go figure, -John == [snip] To summarize: Nobody here does want to insult anyone who does professional audio recordings. But having the knowledge of what the stability and accuracy numbers for an ordinary Rb mean, and being able to put that into perspective with the not so good capabilties of the human sensory systems, one wonders why people spend an awfull lot of money for something that has no audiable effect over something a lot cheaper. Not to mention that other things have a much higher impact on audio quality than the reference oscillator: Like temperature and humidity during recording (do you control them as well to the ppm level?), or the tuning of the instruments which wanders quite a bit during use. Attila Kinali -- Why does it take years to find the answers to the questions one should have asked long ago? ___ 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] Oh dear
On 5/6/2012 7:39 PM, Jim Palfreyman wrote: http://www.ebay.com.au/itm/Antelope-Audio-Isochrone-10M-Rubidium-Atomic-Clock-/270809581736?pt=LH_DefaultDomain_0hash=item3f0d8248a8 Make sure you read the description to discover what it's being sold for. My chuckle for the day. Jim Palfreyman ___ 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. Audiophools strike again Randy ___ 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] Oh dear
On Mon, May 7, 2012 at 8:59 AM, Attila Kinali att...@kinali.ch wrote: On Mon, 07 May 2012 08:20:55 -0700 Dan Rae dan...@verizon.net wrote: I see nothing odd about wanting to get the best possible source for the Master Clock for your master recordings. You are right about that. But there are better clocks at 1/10th of the price. Also in a recording studio, many times you need to phase lock to an existing source and you do NOT want to be dead-on to some specific frequency. Jitter matters more then being frequency accurate. And end use would never hear a 1E-6 absolute frequency error, and I mean never. But relative frequency errors and jitter is audible As for audiophool's home playback systems there is no need at all for an Rb clock. They would do much better with an $50 OCXO in a box. 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] Oh dear
Hi Be careful when you talk about jitter of any device, OCXO's included. There is always an implied bandwidth in the conversion of phase noise to jitter. If you extend the bandwidth down low enough (as in low audio) the jitter goes up quite a bit. In the case of audio, jitter at low frequencies just might be something to worry about. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Attila Kinali Sent: Monday, May 07, 2012 12:19 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Oh dear On Mon, 7 May 2012 10:02:25 -0600 Tom Knox act...@hotmail.com wrote: Actually the numbers are quite real, play with the math, a small amount of jitter in a DAC (X) can have a large difference (Y) when sampling a complex wave form especially in the audiophile world where the sound of 24bit dac 16,777,216 discrete levels is clearly superior to older 16 bit dac 65,536 possible levels in 44.1 KHz to 192 KHz formats. Yes, i know that jitter is a pain when it comes to ADCs, but keep in mind that your audio ADC does have a jitter of a couple 100ps itself. If it's a high end ADC that is. The standard ADCs are usually in the ns range. For a normal 10MHz XO you measure the jitter in in the lower 10ps at most, a good one at lower than 1ps cycle-to-cycle. Of course, you have to keep the clock signal clean of any disturbance that might add modulations to it. But that's a matter of keeping the power supply clean and having the signal shielded. It's not an inherent property of an Rb to have low jitter. And as we all know from the recent hype on the FE-5860As and the following measurements, not all Rb's are low jitter. Attila Kinali -- Why does it take years to find the answers to the questions one should have asked long ago? ___ 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] Oh dear
Isn't long term stability an oxymoron? Or, put another way, a Murphy Mantra? Don MailLists Let's expect the ultimate portable MP3 player with atomic clock reference... :] Also funny are the offerings with RbO CD-clocks... usually tweaked FE-5680s, which are not exactly famous for a clean jitter/spurious free output signal... The only reason is the easiness of output frequency adjustment (for the DDS models) to that of the standard CD clock, which promptly places a premium on the price tag. A good XO is way better and cheaper, with the notable exception of temperature, and long term stability - still waiting for the golden ears capable of hearing that one... On 5/7/2012 12:20 PM, Attila Kinali wrote: On Mon, 07 May 2012 13:40:15 +0530 Rajvu2...@gmail.com wrote: I once did a test with a audio expert and compared a CD and a digital copy. He confirmed that the copy was the original and when I showed him which was which he still refused to believe.. I know a local guy who gold plated the PCBs for his home brewed amp! Well.. there is lots of bogus information going around in the audiophile scene... Probably mostly because todays audio technology is so advanced, that Clarke's 3rd Law applies... But to bring this back to time nutty topics, have a look at http://www.colorfly.eu/product.html It's an MP3 player with high precision timing. It does not only use two TCXOs with5ps Jitter.. No! It also employes a technique known as Jitter Kill for the ultimate mobile sound experience! :-) 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. -- Neither the voice of authority nor the weight of reason and argument are as significant as experiment, for thence comes quiet to the mind. R. Bacon If you don't know what it is, don't poke it. Ghost in the Shell Dr. Don Latham AJ7LL Six Mile Systems LLP 17850 Six Mile Road POB 134 Huson, MT, 59846 VOX 406-626-4304 www.lightningforensics.com www.sixmilesystems.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Oh dear
On 5/7/2012 2:20 AM, Attila Kinali wrote: On Mon, 07 May 2012 13:40:15 +0530 Rajvu2...@gmail.com wrote: I once did a test with a audio expert and compared a CD and a digital copy. He confirmed that the copy was the original and when I showed him which was which he still refused to believe.. I know a local guy who gold plated the PCBs for his home brewed amp! Well.. there is lots of bogus information going around in the audiophile scene... Probably mostly because todays audio technology is so advanced, that Clarke's 3rd Law applies... But to bring this back to time nutty topics, have a look at http://www.colorfly.eu/product.html It's an MP3 player with high precision timing. It does not only use two TCXOs with5ps Jitter.. No! It also employes a technique known as Jitter Kill for the ultimate mobile sound experience! :-) Attila Kinali Yup! Audiophools strike again. . . Randy ___ 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] Oh dear
Suppose you have a perfect, ideal clock that puts out 'convert' pulses at an exact rate is used to strobe a high precision A/D. Now suppose you add jitter to that perfect clock so that the rate stays the same but time interval between successive pulses varies randomly between P(1-x) and P(1+x). How big would x have to be before anyone could detect any difference in the sound? I have my opinion, but what is yours and why? -John === On Mon, 7 May 2012 10:02:25 -0600 Tom Knox act...@hotmail.com wrote: Actually the numbers are quite real, play with the math, a small amount of jitter in a DAC (X) can have a large difference (Y) when sampling a complex wave form especially in the audiophile world where the sound of 24bit dac 16,777,216 discrete levels is clearly superior to older 16 bit dac 65,536 possible levels in 44.1 KHz to 192 KHz formats. Yes, i know that jitter is a pain when it comes to ADCs, but keep in mind that your audio ADC does have a jitter of a couple 100ps itself. If it's a high end ADC that is. The standard ADCs are usually in the ns range. For a normal 10MHz XO you measure the jitter in in the lower 10ps at most, a good one at lower than 1ps cycle-to-cycle. Of course, you have to keep the clock signal clean of any disturbance that might add modulations to it. But that's a matter of keeping the power supply clean and having the signal shielded. It's not an inherent property of an Rb to have low jitter. And as we all know from the recent hype on the FE-5860As and the following measurements, not all Rb's are low jitter. Attila Kinali -- Why does it take years to find the answers to the questions one should have asked long ago? ___ 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] Oh dear
One of my other avocations is precision shooting. I would not like to engage in a contest to see which bunch of aficionados has more folklore Don Javier Herrero El 07/05/2012 11:20, Attila Kinali escribió: But to bring this back to time nutty topics, have a look at http://www.colorfly.eu/product.html It's an MP3 player with high precision timing. It does not only use two TCXOs with 5ps Jitter.. No! It also employes a technique known as Jitter Kill for the ultimate mobile sound experience! :-) Attila Kinali It plays MP3 or uncompressed audio? ;). And the sliding potentiotemer... prone to all kinds of noises and imbalance, and the nice wood enclosure, hand engraved, of course manufactured in a controlled temperature and humidity environment, that no doubt has a very positive effect on the sound, probably as good as the EMC shielding that provides. Also I love this paragraph On month day of year, the technique of circuit named Jitter Kill was registered as a patent for the other special technique of the Pocket HIFI player. When was/will be month day of year? excellent accuracy :) I imagine Steve Wan and his team laughing out loud everytime their get a purchase order. 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. -- Neither the voice of authority nor the weight of reason and argument are as significant as experiment, for thence comes quiet to the mind. R. Bacon If you don't know what it is, don't poke it. Ghost in the Shell Dr. Don Latham AJ7LL Six Mile Systems LLP 17850 Six Mile Road POB 134 Huson, MT, 59846 VOX 406-626-4304 www.lightningforensics.com www.sixmilesystems.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] DPLL for 10MHz
On Mon, 7 May 2012 10:30:56 -0500 Bill Dailey docdai...@gmail.com wrote: Does anyone have any knowledge of a simple (just soldering a few connections and maybe programming a hz/volt rate) PCB for synchronizing a precision OCXO to a GPSDO? I am trying to improve short term stability with a high stability OCXO and dont want to cut into my fury and replace the OCXO. I cando it manually but this seems like it would be nice and desirable for many yet I can't find anything. I presume it would have to be digital because of the long time constant. What speaks against a simple design as used in the GPSDO by James Miller[1]? Or if you want a better PLL than just an XOR gate, use a 74x4046. They are still available in DIL, so building a complete PLL is possible on a veroboard. This should be enough if you want to improve the short term stability below 0.1s, where the fury rises above it's long term humb. If you want to flatten down the humb the fury has (the one between a tau of 1s and x*1000s), then you need a very stable OXCO to begin with. Also, then i think the best approach would be to scale down both signals to 1kHz and use a PICTIC II to measure the phase difference between them. Then you can implement the control loop in the PIC of the PICTIC II and drive an _external_ DAC with it. Attila Kinali [1] http://www.jrmiller.demon.co.uk/projects/ministd/manual.pdf -- Why does it take years to find the answers to the questions one should have asked long ago? ___ 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] Oh dear
Nearly all modern recordings are multiple mono. One microphone per instrument if not more. Multiple overdubs. If high ticket artists are collaborating, they may be recorded at different times. (Bruce Springsteen and Rosanne Cash duet for example.) They want a high bit depth so the final product doesn't have a high background noise. The classic back of the envelope calculation regarding clock jitter is based on 44.1KHz sampling and a 20KHz sine wave. Take the maximum slew rate of the sine wave and the timing uncertainty (jitter), then compare to a LSB. It doesn't take much jitter even at 16 bits to be significant. Modern ADCs are MASH. I don't know the analog to the argument for that technology. -Original Message- From: MailLists li...@medesign.ro Sender: time-nuts-boun...@febo.com Date: Mon, 07 May 2012 19:31:10 To: Discussion of precise time and frequency measurementtime-nuts@febo.com Reply-To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] Oh dear If you take into consideration that the best currently available DACs, also true for analog circuits, have a dynamic range about 120-126dB, the last 3-4 bits are quite irrelevant (random noise mostly)... a good 20bit DAC already pushes the limits. The marketingdroids swarming for the newest 32 bitters is even more ludicrous. On the other side, the dynamic range of the ear (if you care the least for the future of your hearing), and of the quietest available listening spaces, hardly gets to 100dB... Of course, for the DSPs involved in the signal chain, 32bits integer math might not be enough, due to rounding errors. On 5/7/2012 7:02 PM, Tom Knox wrote: Actually the numbers are quite real, play with the math, a small amount of jitter in a DAC (X) can have a large difference (Y) when sampling a complex wave form especially in the audiophile world where the sound of 24bit dac 16,777,216 discrete levels is clearly superior to older 16 bit dac 65,536 possible levels in 44.1 KHz to 192 KHz formats. Thomas Knox Date: Mon, 7 May 2012 17:59:04 +0200 From: att...@kinali.ch To: time-nuts@febo.com Subject: Re: [time-nuts] Oh dear On Mon, 07 May 2012 08:20:55 -0700 Dan Raedan...@verizon.net wrote: I see nothing odd about wanting to get the best possible source for the Master Clock for your master recordings. My son does run a small studio and for him I was able to make a version of that unit, for a lot less money of course. If he says it improves the sound of the recordings, and his customers agree, I am inclined to believe him. The thing is, that an Rb is good for one thing: Have a long term stable and accurate frequency source that is better than 1 to some billions for measurement or other stuff that take more than a few hours or have to be repeated exactly in a couple of weeks. For audio, you need a frequency source that is stable over a couple of hours (probably a working day) and shows low jitter. Where as low jitter is quite high in time-nuts terms and stable not stable at all. A cycle-to-cylcle jitter of a couple of ns is not audioable at all, but any Rb will have a much lower jitter. Or to have a different look at it, you want to have very low phase noise, as this phase noise is mixed in over the ADCs into your signal. But as we know, the phase noise of an Rb is not defined by the Rb physics package, but by the OCXO they use. (yes i know that the close in phase noise is defined by the reference and not by the OCXO, but the base level is the OCXO, not the reference) As for stability. You want the instruments to sound the same over an recording. Ie the human ear has to preceive the recorded sound as the same. The frequency resolution of the human ear is somewhere around 3Hz. This makes for 150ppm (at 20kHz). Even a 32kHz tuning fork crystal achieves an absolute accuracy that is better than this. Its stability is much better than this Of course, you want to have enought headroom for other non ideal components. So, lets say, go for a factor of 10, then we are at 15ppm. For absolute accuracy, that's already a good XO. For stability, still most XO should do that. Or to say it differently: Using some good OCXO with low or very low phase noise would be more than enough for even the most high end audio equipment. You don't even have to discipline it, as a even quite bad OCXO has variations much lower than 1ppm, which is definitly not something anyone can hear. IMHO getting a 20-50USD OCXO from ebay, some good, low noise power supply (audio power supplies with low noise in the40kHz region), some distribution amplifier with low noise figure and you are set. All in all probably at a cost of 200-300USD including rack mount. If you want to have high fidelity you can use an GPSDO to get your OCXO within a couple mHz. To summarize: Nobody here does want to insult anyone who does professional audio recordings.
[time-nuts] GPS filtering (was: Oh dear)
On Mon, 07 May 2012 08:11:53 -0700 Jim Lux jim...@earthlink.net wrote: - the recent GPS filtering thing.. You mean the Don't GPS your Rb thread? it took a YEAR for someone in the PNT community to finally come up with a good, simple explanation of why L^2 arguments were invalid. And it comes down to the fact that GPS isn't a communication link, so you can't use that conceptual model to analyze it. Once you get that, then people go oh! That's why we can't do that and have it still work Uhm.. i don't understand at all. Could you give some pointers or explain what L^2 and the rest is? Thanks in advance Attila Kinali -- Why does it take years to find the answers to the questions one should have asked long ago? ___ 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] Something better than a Thunderbolt?
My apologies if is missed it, but will there be official support of the nortel version in some future release of LH? On Thu, May 3, 2012 at 5:02 AM, Mark Sims hol...@hotmail.com wrote: Recently Sam managed to poke and prod a Trimble/Nortel GPSTM (NTGS50AA) enough to wake it up out of its slumber and be recognized by Lady Heather. The NTGS50AA is a version of the Thunderbolt done for Nortel. It has some interesting features (like hot-upgradable firmware, single 24 or 48V power input, cheaper than a tbolt, etc. It also has a few warts... no TSIP command documentation being the main one and a few commands are definitely different than the Tbolt. The wakeup technique is rather crude and can take a couple of minutes (shout a particular command into its ear until it wakes up). Trimble's software manages to get it talking immediately. Duplicating the commands that Trimble sends does not seem to work. Once it wakes up, it stays awake until you power cycle it or run Trimble's software. I purchased one of these units from an Ebay seller in Old Cathay (around $70 or make offer plus $30 shipping) to see what it would take to add support to Lady Heather. My unit came in a week or so later. I hacked a 48V power connection (literally) onto the board and powered it up with a wall wart. After some futzing and puzzling over the proper ribbon cable orientation between the main board and front panel board, I got the unit woken up using Sam's technique and puzzled out the commands to make the oscillator disciplining (time constant, damping, dac gain, etc) work. The old survey location was in a sketchy Guatemalan smuggler's haven border town at what looks like a private residence. After running it a while, it became apparent that it works better than the Thunderbolt. The temperature sensor does not have those glitches that plague the tbolt. The receiver has a bit more sensitivity. And, best of all, the oscillator is pretty much immune to external temperature changes (the Tbolt oscillator makes a good thermometer). The reported OSC and PPS rms errors are exceedingly low... you have to actively thermally stabilize the Tbolt to approach these numbers. Hopefully this quality extends to its phase noise, etc spec. It would be interesting to see what thermally stabilizing the unit would do... ___ 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. -- --Eric _ Eric Garner ___ 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] GPS filtering
On 05/07/2012 07:01 PM, Attila Kinali wrote: On Mon, 07 May 2012 08:11:53 -0700 Jim Luxjim...@earthlink.net wrote: - the recent GPS filtering thing.. You mean the Don't GPS your Rb thread? it took a YEAR for someone in the PNT community to finally come up with a good, simple explanation of why L^2 arguments were invalid. And it comes down to the fact that GPS isn't a communication link, so you can't use that conceptual model to analyze it. Once you get that, then people go oh! That's why we can't do that and have it still work Uhm.. i don't understand at all. Could you give some pointers or explain what L^2 and the rest is? Ligthsquared and their LTE system that threatend to noise out GPS from US. Loads of messages on that on the list already. 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] DPLL for 10MHz
On Mon, May 7, 2012 at 9:54 AM, Attila Kinali att...@kinali.ch wrote: What speaks against a simple design as used in the GPSDO by James Miller[1]? Or if you want a better PLL than just an XOR gate, use a 74x4046. They are still available in DIL, so building a complete PLL is possible on a veroboard. This should be enough if you want to improve the short term stability below 0.1s, where the fury rises above it's long term humb. That is my solution. The 74x4046 come in a version that will do 10MHz. I use it to let a 10MHz reference that has poor short term noise drive an OCXO.It's all analog and not many parts. 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] DPLL for 10MHz
I am patiently waiting for the code to drive the DAC. Bert Kehren In a message dated 5/7/2012 12:54:54 P.M. Eastern Daylight Time, att...@kinali.ch writes: On Mon, 7 May 2012 10:30:56 -0500 Bill Dailey docdai...@gmail.com wrote: Does anyone have any knowledge of a simple (just soldering a few connections and maybe programming a hz/volt rate) PCB for synchronizing a precision OCXO to a GPSDO? I am trying to improve short term stability with a high stability OCXO and dont want to cut into my fury and replace the OCXO. I cando it manually but this seems like it would be nice and desirable for many yet I can't find anything. I presume it would have to be digital because of the long time constant. What speaks against a simple design as used in the GPSDO by James Miller[1]? Or if you want a better PLL than just an XOR gate, use a 74x4046. They are still available in DIL, so building a complete PLL is possible on a veroboard. This should be enough if you want to improve the short term stability below 0.1s, where the fury rises above it's long term humb. If you want to flatten down the humb the fury has (the one between a tau of 1s and x*1000s), then you need a very stable OXCO to begin with. Also, then i think the best approach would be to scale down both signals to 1kHz and use a PICTIC II to measure the phase difference between them. Then you can implement the control loop in the PIC of the PICTIC II and drive an _external_ DAC with it. Attila Kinali [1] http://www.jrmiller.demon.co.uk/projects/ministd/manual.pdf -- Why does it take years to find the answers to the questions one should have asked long ago? ___ 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] Oh dear
That was a big problem with the dynamic range of tape recorders, which had to be solved with noise reduction circuits. Even good 16 bit ADCs have a higher DR than the SNR of most instruments in quiet recording studios. With the mixing of multiple dubs, the main problem is the summed background noise, not that of the ADCs. When doing the mix digitally, a DAW with higher bit depth is needed, to conserve the DR: 16 tracks need another 4 bits. The downmix can then be truncated to the final media bit depth (eventually with some dither added, if not self-dithered due to noise). The main problem with the old CD format wasn't actually the DR, the SR was chosen too low. One of the famous audiophile studios (Chesky Records) expressly avoids overdubbing, and postprocessing, and puts accent on the microphone placement. That's real art, unlike some sound engineer using heavy processing, and turning up the compression control, for a louder sound. Modern AD/DA-Cs are mostly sigma-delta for technological, and cost reasons. The better ones are also multi-bit... On 5/7/2012 7:59 PM, li...@lazygranch.com wrote: Nearly all modern recordings are multiple mono. One microphone per instrument if not more. Multiple overdubs. If high ticket artists are collaborating, they may be recorded at different times. (Bruce Springsteen and Rosanne Cash duet for example.) They want a high bit depth so the final product doesn't have a high background noise. The classic back of the envelope calculation regarding clock jitter is based on 44.1KHz sampling and a 20KHz sine wave. Take the maximum slew rate of the sine wave and the timing uncertainty (jitter), then compare to a LSB. It doesn't take much jitter even at 16 bits to be significant. Modern ADCs are MASH. I don't know the analog to the argument for that technology. -Original Message- From: MailListsli...@medesign.ro Sender: time-nuts-boun...@febo.com Date: Mon, 07 May 2012 19:31:10 To: Discussion of precise time and frequency measurementtime-nuts@febo.com Reply-To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] Oh dear If you take into consideration that the best currently available DACs, also true for analog circuits, have a dynamic range about 120-126dB, the last 3-4 bits are quite irrelevant (random noise mostly)... a good 20bit DAC already pushes the limits. The marketingdroids swarming for the newest 32 bitters is even more ludicrous. On the other side, the dynamic range of the ear (if you care the least for the future of your hearing), and of the quietest available listening spaces, hardly gets to 100dB... Of course, for the DSPs involved in the signal chain, 32bits integer math might not be enough, due to rounding errors. On 5/7/2012 7:02 PM, Tom Knox wrote: Actually the numbers are quite real, play with the math, a small amount of jitter in a DAC (X) can have a large difference (Y) when sampling a complex wave form especially in the audiophile world where the sound of 24bit dac 16,777,216 discrete levels is clearly superior to older 16 bit dac 65,536 possible levels in 44.1 KHz to 192 KHz formats. Thomas Knox Date: Mon, 7 May 2012 17:59:04 +0200 From: att...@kinali.ch To: time-nuts@febo.com Subject: Re: [time-nuts] Oh dear On Mon, 07 May 2012 08:20:55 -0700 Dan Raedan...@verizon.net wrote: I see nothing odd about wanting to get the best possible source for the Master Clock for your master recordings. My son does run a small studio and for him I was able to make a version of that unit, for a lot less money of course. If he says it improves the sound of the recordings, and his customers agree, I am inclined to believe him. The thing is, that an Rb is good for one thing: Have a long term stable and accurate frequency source that is better than 1 to some billions for measurement or other stuff that take more than a few hours or have to be repeated exactly in a couple of weeks. For audio, you need a frequency source that is stable over a couple of hours (probably a working day) and shows low jitter. Where as low jitter is quite high in time-nuts terms and stable not stable at all. A cycle-to-cylcle jitter of a couple of ns is not audioable at all, but any Rb will have a much lower jitter. Or to have a different look at it, you want to have very low phase noise, as this phase noise is mixed in over the ADCs into your signal. But as we know, the phase noise of an Rb is not defined by the Rb physics package, but by the OCXO they use. (yes i know that the close in phase noise is defined by the reference and not by the OCXO, but the base level is the OCXO, not the reference) As for stability. You want the instruments to sound the same over an recording. Ie the human ear has to preceive the recorded sound as the same. The frequency resolution of the human ear is somewhere around 3Hz. This makes for 150ppm (at 20kHz). Even a 32kHz tuning fork crystal achieves an absolute
Re: [time-nuts] Oh dear
In message 4fa7fb9b.3040...@yahoo.com, Randy D. Hunt writes: On 5/6/2012 7:39 PM, Jim Palfreyman wrote: http://www.ebay.com.au/itm/Antelope-Audio-Isochrone-10M-Rubidium-Atomic-Clock-/270809581736?pt=LH_DefaultDomain_0hash=item3f0d8248a8 Make sure you read the description to discover what it's being sold for. The name of the company is even funnier: Sonic Circus :-) -- 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] GPS filtering
On Mon, 07 May 2012 19:07:12 +0200 Magnus Danielson mag...@rubidium.dyndns.org wrote: Uhm.. i don't understand at all. Could you give some pointers or explain what L^2 and the rest is? Ligthsquared and their LTE system that threatend to noise out GPS from US. Loads of messages on that on the list already. Oh.. right... I completely forgot about that now that it's over. (not to mention that it didn't interest me that much being on an different continent and all) Attila Kinali -- Why does it take years to find the answers to the questions one should have asked long ago? ___ 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] Oh dear
In message d2251f0f290d4b1ab54e1a4dba345...@vectron.com, Bob Camp writes: If you extend the bandwidth down low enough (as in low audio) the jitter goes up quite a bit. In the case of audio, jitter at low frequencies just might be something to worry about. Not with the kind of physical laws I live in. At low audio frequencies, say 100 Hz, you have at least 441 samples per period of audio, and the Y-difference from one sample to the next is so small, that no amount of jitter will have sonic impact. At a 20 kHz frequency however, you have sign reversal from sample to sample and moving a sample in X has very high impact on the energy of that and the surrounding samples. This is exactly why we use oversampling in the first place: You get more gentle slopes from sample to sample which means that the jitters effect is attenuated in the result. The place where this audio-jitter-homoepathy comes from, is the first generation of Philips CD players, CD-100 etc, which had jitter come up from the poor mechanics, because there were insufficient buffering before the de-interleaver. -- 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] DPLL for 10MHz
On Mon, 7 May 2012 12:17:02 -0500 Bill Dailey docdai...@gmail.com wrote: Regarding the vectron tru-050 looks nice but requires me to come up with a board and resistors and capacitors etc which is above my ability. Uhmm... how far does your abilities go? I looked at the miller thing but what I want to do is only correct the oscillator like every 500-1000 seconds. I want to do more than smooth out the hump. I am playing with short term stability of mid 10-13 sub 1s to 10-12 at between 500 and 1000s. Yes, it is a good oscillator but not BVA good. Read the recent Don't GPS' your Rb threat, it explains why you want to update/correct your oscillator more often than every 500 seconds. Also, if you want to go down to that level, a lot more is important than just the right GPS receiver and the right PLL. You want to think how you want to supply power to your system with very little noise on it. How you want to connect the components without picking up too much noise, neither E nor H field. etc pp. It is easiest, if you do a PCB, then you can control a lot of the stuff without too much effort. Building it on a veroboard is not recomended. Instead use a solid ground plane (ie copper plate) to mount your stuff on, if you want to do it prototype style. Atila Kinali -- Why does it take years to find the answers to the questions one should have asked long ago? ___ 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] Oh dear
In message 62172.12.6.201.2.1336409319.squir...@popaccts.quikus.com, J. Fors ter writes: Suppose you have a perfect, ideal clock that puts out 'convert' pulses at an exact rate is used to strobe a high precision A/D. Now suppose you add jitter to that perfect clock so that the rate stays the same but time interval between successive pulses varies randomly between P(1-x) and P(1+x). How big would x have to be before anyone could detect any difference in the sound? You have to tell us the sampling frequency before we can answer. -- 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] Oh dear
Analog Devices and Linear Technology have application notes on this subject. At least with sampling converters, jitter directly limits dynamic range. My back of the envelope calculation comes up with about 25ps of RMS jitter for an ideal 16 bit sampling converter at audio frequencies but most delta-sigma converters should tolerate higher levels. Analog Devices says 100s of ps of clock jitter is acceptable for them. How low can the dynamic range be before it becomes audible? On Mon, 7 May 2012 09:48:39 -0700 (PDT), J. Forster j...@quikus.com wrote: Suppose you have a perfect, ideal clock that puts out 'convert' pulses at an exact rate is used to strobe a high precision A/D. Now suppose you add jitter to that perfect clock so that the rate stays the same but time interval between successive pulses varies randomly between P(1-x) and P(1+x). How big would x have to be before anyone could detect any difference in the sound? I have my opinion, but what is yours and why? -John === On Mon, 7 May 2012 10:02:25 -0600 Tom Knox act...@hotmail.com wrote: Actually the numbers are quite real, play with the math, a small amount of jitter in a DAC (X) can have a large difference (Y) when sampling a complex wave form especially in the audiophile world where the sound of 24bit dac 16,777,216 discrete levels is clearly superior to older 16 bit dac 65,536 possible levels in 44.1 KHz to 192 KHz formats. Yes, i know that jitter is a pain when it comes to ADCs, but keep in mind that your audio ADC does have a jitter of a couple 100ps itself. If it's a high end ADC that is. The standard ADCs are usually in the ns range. For a normal 10MHz XO you measure the jitter in in the lower 10ps at most, a good one at lower than 1ps cycle-to-cycle. Of course, you have to keep the clock signal clean of any disturbance that might add modulations to it. But that's a matter of keeping the power supply clean and having the signal shielded. It's not an inherent property of an Rb to have low jitter. And as we all know from the recent hype on the FE-5860As and the following measurements, not all Rb's are low jitter. Attila Kinali -- Why does it take years to find the answers to the questions one should have asked long ago? ___ 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] Oh dear
In message 4fa80913.7000...@medesign.ro, MailLists writes:
That was a big problem with the dynamic range of tape recorders, which
had to be solved with noise reduction circuits. Even good 16 bit ADCs
have a higher DR than the SNR of most instruments in quiet recording
studios.
Not so fast there...
Yes, in theory your ADC could digitize a signal 14*6 = 84 dB below
reference level, but it would do so with 50% distortion, because
there would only be three distinct levels: {-1, 0, +1}
This is a much overlooked issue, in particular with classical music
where dynamics in the music can account for way more dB than people
realize.
We must start out by defining the acceptable level of total distortion,
if we choose 0.5% then we need 200 digital levels, roughly 8 of
your 16 bits for the signal.
That gives you a headroom of 7 bits (leaving one for the sign) and
that gives you 42 dB of S/N.
That isn't very much, headroom, 42dB, when the conductor waves the
entire philharmonic AND the full opera choir in, for for that wonderful
Dies Ira of Verdis. Or Carmina Burana. Or any of the many
other 'shock-effects' classical composers have enjoyed.
With digital, you get most distortion at weak signals, where your
ears are much better at detecting it, with vinyl you get more
distortion on strong signals, just like your ears, meaning the
level becomes unbearable sooner.
That is why, in plain and simple terms, classical struggles with
digital: High distortion in weak passages.
It is also why the CD media has changed rythmic music, which
went from a love of distortion to a love of pure tones when
the CD media made it possible to play loud pure tones.
--
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.
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Re: [time-nuts] Oh dear
On Mon, 2012-05-07 at 18:15 +, Poul-Henning Kamp wrote: We must start out by defining the acceptable level of total distortion, if we choose 0.5% then we need 200 digital levels, roughly 8 of your 16 bits for the signal. That gives you a headroom of 7 bits (leaving one for the sign) and that gives you 42 dB of S/N. Not true in a correctly dithered quantizer (And they almost all are these days)... This is counter intuitive, but adding 1 LSB of uncorrelated noise having the correct statistical properties (Triangular probability distribution) has the effect of completely linearising the conversion process at the cost of adding about 3dB of noise to the system. With the noise added you can hear narrow tones well below the wideband noise floor. In a correctly dithered system the broadband noise floor is the only thing determined by the word length, and narrow band signals can be resolved to well below the noise floor. Further, as the statistical properties of the noise are not all that tightly coupled to its frequency domain properties, it is possible to filter the noise to move most of the energy away from the regions where the ear is most sensitive. 16 bits is actually fine as a distribution format, where is shows up as a little short is as a capture format as at capture time you need headroom to ensure nothing unexpected causes clipping, but once you are done with the processing it is trivial to strip the headroom out and dither down to 16 bits. This discussion would be better over on the Pro audio list rather then time nuts. 73, Dan. ___ 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] Oh dear
In message 1336415866.16321.14.camel@laptop, Dan Mills writes: On Mon, 2012-05-07 at 18:15 +, Poul-Henning Kamp wrote: 16 bits is actually fine as a distribution format, Yes, I agree with that, and lets use that agreement to stop the topic :-) -- 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] Oh dear
On Mon, May 7, 2012 at 11:15 AM, Poul-Henning Kamp p...@phk.freebsd.dk wrote: We must start out by defining the acceptable level of total distortion, if we choose 0.5% then we need 200 digital levels, roughly 8 of your 16 bits for the signal. That gives you a headroom of 7 bits (leaving one for the sign) and that gives you 42 dB of S/N. That isn't very much, headroom, 42dB, when the conductor waves the entire philharmonic AND the full opera choir in, for for that wonderful Dies Ira of Verdis. Or Carmina Burana. Or any of the many other 'shock-effects' classical composers have enjoyed. You are mixing recording and distribution. The 16-bit 44.1K CD Quality is for distribution to consumers. Few people record with that format. 24-bits and 96K is a common recording format. and then later it is mastered to fit within the CD format.And don't forget that some tools the mastering engineer has are EQ, dithering and frequency dependent compression. It is VERY rare that a performance would be linearly transliterated to the CD. What you get is something that was modified to sound good on consumer playback equipment. With good being the engineer's person opinion. Back to recording. It is common to have the master studio clock be an OCXO. This would drive the (96K) sample clock and it is the sample clock that gets distributed inside the rack. My cheep home system, I think has a low cost XO inside and is pretty much jitter free. Simple XOs can be pretty good especially what you care more about clean than accurate 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] Oh dear
On 05/07/2012 08:15 PM, Poul-Henning Kamp wrote:
In message4fa80913.7000...@medesign.ro, MailLists writes:
That was a big problem with the dynamic range of tape recorders, which
had to be solved with noise reduction circuits. Even good 16 bit ADCs
have a higher DR than the SNR of most instruments in quiet recording
studios.
Not so fast there...
Yes, in theory your ADC could digitize a signal 14*6 = 84 dB below
reference level, but it would do so with 50% distortion, because
there would only be three distinct levels: {-1, 0, +1}
This is a much overlooked issue, in particular with classical music
where dynamics in the music can account for way more dB than people
realize.
We must start out by defining the acceptable level of total distortion,
if we choose 0.5% then we need 200 digital levels, roughly 8 of
your 16 bits for the signal.
That gives you a headroom of 7 bits (leaving one for the sign) and
that gives you 42 dB of S/N.
That isn't very much, headroom, 42dB, when the conductor waves the
entire philharmonic AND the full opera choir in, for for that wonderful
Dies Ira of Verdis. Or Carmina Burana. Or any of the many
other 'shock-effects' classical composers have enjoyed.
With digital, you get most distortion at weak signals, where your
ears are much better at detecting it, with vinyl you get more
distortion on strong signals, just like your ears, meaning the
level becomes unbearable sooner.
That is why, in plain and simple terms, classical struggles with
digital: High distortion in weak passages.
It is also why the CD media has changed rythmic music, which
went from a love of distortion to a love of pure tones when
the CD media made it possible to play loud pure tones.
The late Julian Dunn has covered this in AES papers and pre-prints.
It relates to side-band, modulation frequency and masking-effects. He
came up with a sinusoidal modulation mask.
Look up his work!
Cheers,
Magnus
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Re: [time-nuts] Oh dear
In message cabbxvhuasdq-mwug6fmwc4ln-d3zkhegvpvvbpcprwxewgf...@mail.gmail.com , Chris Albertson writes: You are mixing recording and distribution. The 16-bit 44.1K CD Quality is for distribution to consumers. I'm old enough to have listend to comparisons when 16 bit 44.1KHz was _both_ recoding and distribution format :-) As I said: one of the main drivers for oversampling is to relax requirements for analog and clock precision. What you get is something that was modified to sound good on consumer playback equipment. With good being the engineer's person opinion. Or in the case of an entire generation worth of european classical recordings: good being equal to Karajan can hear it through his increasingly severe deafness :-) -- 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] Oh dear
New question about jitter in recording.I was reading some time ago about non-uniform sampling. Basically the time between samples is random (or as random as you can make it) But now you have to sample a clock AND the signal. Or more likely use a psuedorandon sample interval that can be reconstructed without clock samples The main problem with this technique is that few people understand the math. For example what is the frequency response of a system with a given mean and standard deviation sample period? Advantages are that you can sample higher frequency than 1/2 the average sample rate and alieasing is less a problem. 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] Oh dear
In message cabbxvhtad_ewe_ptrmkifkrywzjfhw3xmypfev6b5su3xw+...@mail.gmail.com , Chris Albertson writes: Advantages are that you can sample higher frequency than 1/2 the average sample rate and alieasing is less a problem. Disadvantage: on playback you get both a sample and a standard deviation :-) I don't think anybody uses random sampling unless they have to (think when can we actually see this star with this telescope etc) -- 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] Oh dear
j...@quikus.com said: Suppose you have a perfect, ideal clock that puts out 'convert' pulses at an exact rate is used to strobe a high precision A/D. Now suppose you add jitter to that perfect clock so that the rate stays the same but time interval between successive pulses varies randomly between P(1-x) and P(1+x). How big would x have to be before anyone could detect any difference in the sound? It's easy enough to work out the right ballpark. Feed a theoretical sine wave into your A/D. Set it to the max amplitude and max frequency that you expect the system to handle. Look at the zero crossing (max slope). How much time does it take for the signal to transition from an output of 0 to an output of 1 (LSB). If your clock if off by that much in time, the analog voltage that you sample will be off by 1 bit. It's a big deal at radar frequencies, less so at audio. You want to make sure that you don't use one of the oscillator packages that has a programmable PLL. Their jitter specs are nasty. -- These are my opinions, not necessarily my employer's. 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] Interesting paper: Don't GPSD' your Rb...
OK, got it. Yes, something like the dithering with a DAC to increase the resolution. On Mon, May 7, 2012 at 6:52 PM, Magnus Danielson mag...@rubidium.dyndns.org wrote: Azelio, On 05/07/2012 09:56 AM, Azelio Boriani wrote: Magnus, If you flip back and forth, then it makes sense because your phase deviationswill be less. Can you further explain this? Thanks. Certainly! Consider that you flip back and forth between two levels, let's just say 50% high and 50% low, the rate of flips considering the time-constant of the adjustment will matter, since if you let the time be so long that the alignment ring out you will get maxium frequency and phase deviation, where as if the rate of flipping is higher, then it drift just a little towards high when it gets a low and drift towards that... which gives you much smaller phase and frequency deviations... and you stay very close to the 50% level between high and low. Essentially, the time-constant of the low-pass filtering will for a higher rate fairly well dampen the changes where as slow changes is in the pass-band with almost no low-pass filtering effects. It is thus nothing stranger than a low-pass filter and a square-wave of different frequencies. Also, if you update to slowly, you will build up larger errors before you have to steer back since you measured an error. Too low comparator rate in a PLL forces heavy filtering just to lower that comparator sub-frequency. Using high enough rate, the filtering process will be more continuous rather than very obviously sampled oriented. I've been bitten by this before. I've seen what too low comparator frequency does to create instability and modulations. 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] Interesting paper: Don't GPSD' your Rb...
Hi Azelio, On 05/07/2012 10:13 PM, Azelio Boriani wrote: OK, got it. Yes, something like the dithering with a DAC to increase the resolution. Indeed. Now, consider now that the variations can come from any form of noise source. Another thing I've learned is that the longer you wait with a correction, the larger the deviation becomes and lower frequency it will have... and both makes it harder to suppress by filtering. It's really just the same thing form another angle. 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] Interesting paper: Don't GPSD' your Rb...
Yes, interesting, now I realize... but: the larger the deviation becomes and lower frequency it will have... and both makes it harder to suppress by filtering. Filtering at what level? Lengthen the sampling time? The average build up? That is, now I'm not aware and think that I have to correct as slowly as possible because I think that the oscillator has to be disturbed to a minimum. Then I see low frequency large deviations, so I think, OK, I have to average longer to account for. Is this the filtering you are referring to? So that one ends up increasing the slowness of the system getting only very slow frequency very large deviations. Thanks for the help On Mon, May 7, 2012 at 10:33 PM, Magnus Danielson mag...@rubidium.dyndns.org wrote: Hi Azelio, On 05/07/2012 10:13 PM, Azelio Boriani wrote: OK, got it. Yes, something like the dithering with a DAC to increase the resolution. Indeed. Now, consider now that the variations can come from any form of noise source. Another thing I've learned is that the longer you wait with a correction, the larger the deviation becomes and lower frequency it will have... and both makes it harder to suppress by filtering. It's really just the same thing form another angle. 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] DPLL for 10MHz
OK, so 1 PPS GPS to Rb - need a TIC; 10MHz Rb to OCXO - need a PLL. Are you interested in an all digital 10nS single shot TIC that gives you a 2's complement number (negative at the left of the GPS PPS and positive at the right)? Here it is. This is my TIC, I use it on all my GPSDOs. LIBRARY IEEE; USE IEEE.STD_LOGIC_1164.ALL; USE IEEE.STD_LOGIC_UNSIGNED.ALL; ENTITY PPSPSI IS PORT (PPSTIEOut: OUT std_logic_vector (23 downto 0); PPSInA, PPSInB, Clock100, Clock20: IN std_logic); END ENTITY PPSPSI; ARCHITECTURE RippleCounter OF PPSPSI IS SIGNAL PPSPhaseCntAB, PPSPhaseCntBA: std_logic_vector (22 downto 0); SIGNAL PPSPhaseLtc: std_logic_vector (23 downto 0); SIGNAL PPSADlyed, PPSBDlyed: std_logic_vector (4 downto 0); SIGNAL PPSGateAB, PPSGateBA, PPSLtcA, PPSRstA, PPSLtcB, PPSRstB, StopCntAB, StopCntBA: std_logic; SIGNAL RstGateAB, RstGateBA, OvrLtcAB, OvrLtcBA, PPSLtcA1, PPSLtcB1, PPSA2BSign: std_logic; BEGIN PPSAtoBSign: PROCESS --Sign will be 1 when A leads B (that is the TIE is negative) BEGIN WAIT UNTIL PPSInB'EVENT AND PPSInB='1'; PPSA2BSign= PPSInA; END PROCESS PPSAtoBSign; PPSAtoBGate: PROCESS (PPSInA, RstGateAB) BEGIN IF RstGateAB='1' THEN PPSGateAB= '0'; ELSIF PPSInA'EVENT AND PPSInA='1' THEN PPSGateAB= '1'; END IF; END PROCESS PPSAtoBGate; PPSBtoAGate: PROCESS (PPSInB, RstGateBA) BEGIN IF RstGateBA='1' THEN PPSGateBA= '0'; ELSIF PPSInB'EVENT AND PPSInB='1' THEN PPSGateBA= '1'; END IF; END PROCESS PPSBtoAGate; PPSADelay: PROCESS BEGIN WAIT UNTIL Clock20'EVENT AND Clock20='1'; PPSADlyed= PPSADlyed (3 downto 0)PPSInA; END PROCESS PPSADelay; PPSBDelay: PROCESS BEGIN WAIT UNTIL Clock20'EVENT AND Clock20='1'; PPSBDlyed= PPSBDlyed (3 downto 0)PPSInB; END PROCESS PPSBDelay; PPSPhaseErrAB0: PROCESS (Clock100, PPSRstB) --Phase error counter bit 0 clocked by the gated 100MHz BEGIN IF PPSRstB='1' THEN PPSPhaseCntAB (0)= '1'; ELSIF Clock100'EVENT AND Clock100='1' THEN IF PPSGateAB='1' AND StopCntAB='0' THEN PPSPhaseCntAB (0)= NOT PPSPhaseCntAB (0); END IF; END IF; END PROCESS PPSPhaseErrAB0; PPSPhaseErrAB: FOR I IN 1 TO 22 GENERATE PPSPhaseErrABi: PROCESS (PPSPhaseCntAB (I-1), PPSRstB) --Phase error counter bit 1 BEGIN IF PPSRstB='1' THEN PPSPhaseCntAB (I)= '1'; ELSIF PPSPhaseCntAB (I-1)'EVENT AND PPSPhaseCntAB (I-1)='1' THEN PPSPhaseCntAB (I)= NOT PPSPhaseCntAB (I); END IF; END PROCESS PPSPhaseErrABi; END GENERATE PPSPhaseErrAB; PPSPhaseErrBA0: PROCESS (Clock100, PPSRstA) --Phase error counter bit 0 clocked by the gated 100MHz BEGIN IF PPSRstA='1' THEN PPSPhaseCntBA (0)= '0'; ELSIF Clock100'EVENT AND Clock100='1' THEN IF PPSGateBA='1' AND StopCntBA='0' THEN PPSPhaseCntBA (0)= NOT PPSPhaseCntBA (0); END IF; END IF; END PROCESS PPSPhaseErrBA0; PPSPhaseErrBA: FOR I IN 1 TO 22 GENERATE PPSPhaseErrBAi: PROCESS (PPSPhaseCntBA (I-1), PPSRstA) --Phase error down counter BEGIN IF PPSRstA='1' THEN PPSPhaseCntBA (I)= '0'; ELSIF PPSPhaseCntBA (I-1)'EVENT AND PPSPhaseCntBA (I-1)='0' THEN PPSPhaseCntBA (I)= NOT PPSPhaseCntBA (I); END IF; END PROCESS PPSPhaseErrBAi; END GENERATE PPSPhaseErrBA; StopCntAB= '1' WHEN PPSPhaseCntAB (22 downto 1)=00 ELSE '0'; StopCntBA= '1' WHEN PPSPhaseCntBA (22 downto 1)=11 ELSE '0'; PPSPhaseLtc= '0'PPSPhaseCntBA WHEN PPSLtcA='1' AND PPSA2BSign='0' AND StopCntBA='0' ELSE '1'PPSPhaseCntAB WHEN PPSLtcB='1' AND PPSA2BSign='1' AND StopCntAB='0' ELSE PPSPhaseLtc; OvrLtcAB= StopCntAB WHEN PPSLtcB1='1' ELSE OvrLtcAB; OvrLtcBA= StopCntBA WHEN PPSLtcA1='1' ELSE OvrLtcBA; RstGateAB= '1' WHEN PPSInB='1' AND PPSBDlyed (1)='0' ELSE '0'; RstGateBA= '1' WHEN PPSInA='1' AND PPSADlyed (1)='0' ELSE '0'; PPSLtcA= '1' WHEN PPSADlyed=00011 ELSE '0'; PPSLtcA1= '1' WHEN PPSADlyed=1 ELSE '0'; --To be used by the terminal count value PPSRstA= '1' WHEN PPSADlyed=0 ELSE '0'; PPSLtcB= '1' WHEN PPSBDlyed=00011 ELSE '0'; PPSLtcB1= '1' WHEN PPSBDlyed=1 ELSE '0'; --To be used by the terminal count value PPSRstB= '1' WHEN PPSBDlyed=0 ELSE '0'; PPSTIEOut= 0111 WHEN OvrLtcAB='1' AND OvrLtcBA='1' AND PPSPhaseLtc (23)='0' ELSE 1000 WHEN OvrLtcAB='1' AND OvrLtcBA='1' AND PPSPhaseLtc (23)='1' ELSE PPSPhaseLtc; END ARCHITECTURE RippleCounter; On Mon, May 7, 2012 at 7:58 PM, ewkeh...@aol.com wrote: 10 MHz between Rb and OCXO 1 pps between GPS and Rb. Always a Rb with GPS. Bert Kehren In a message dated 5/7/2012 1:30:57 P.M. Eastern Daylight Time, azelio. bori...@screen.it writes: Using the PPS as a sync source? On Mon, May 7, 2012 at 6:24 PM, ewkeh...@aol.com wrote: Tried, no interest, some one has offered to in the future do a gate array version, you may want to wait for that I am in the mean time using am analog loop for less than 100 seconds between Rb and OCXO and a very modified Shera for GPS/Rb. Works for me. Contact me off list and we can talk. Bert In a message dated 5/7/2012 12:05:54 P.M. Eastern Daylight Time, garn...@gmail.com writes: This is something I would also like
Re: [time-nuts] DPLL for 10MHz
Regarding my abilities.. regarding electronics... poor soldering is about my limit... through hole only. That is why I was hoping there was some off the shelf method that I could wire up with 10 MHz in from the gspdo and from the oscillator then wire up the EFC volatge and set the required parameters and it would adjust my oscillator to the same frequency as the GPSDO. Sounds simple enough to me. but apparently not. I guess I need to figure out how to do this electronics stuff...incidentally avoidance of 1) foreign languages, 2) drafting and 3) electronics is why I chose to become a chemical engineer.. hi hi. I once accidentally signed up for a physics lab that involved electronics... made it through the first lab period.. was like a fish out of water... walked immediately to administration and dropped it. Oscilla-what I said as I skipped out of there. It was all electrical engineers. -- Doc Bill Dailey KXØO ___ 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] Interesting paper: Don't GPSD' your Rb...
On 05/07/2012 10:59 PM, Azelio Boriani wrote: Yes, interesting, now I realize... but: the larger the deviation becomes and lower frequency it will have... and both makes itharder to suppress by filtering. Filtering at what level? Lengthen the sampling time? The average build up? That is, now I'm not aware and think that I have to correct as slowly as possible because I think that the oscillator has to be disturbed to a minimum. Then I see low frequency large deviations, so I think, OK, I have to average longer to account for. Is this the filtering you are referring to? So that one ends up increasing the slowness of the system getting only very slow frequency very large deviations. Thanks for the help If you have a little frequency error the longer you wait to do any adjustment the larger phase-deviation that frequency error will result in. If you sample to seldom, then you rely on your DAC resolution and stability inbetween your samples, the clock will essentially be in hold-over. If this is 1 ms, 1 s or 1000 s will make a difference. That relates to sampling rate, which puts a limit to the loop bandwidth you can have. But my main reaction was to the sample-rate vs. measure and adjust rate (i.e. sample rate), and I wanted to point out that there is a merit in sampling (much) faster. The modulation waveform is only to illustrate the averaging behaviour. 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] DPLL for 10MHz
I'm running (although running isn't quite correct for VHDL) this on a 50Kgates Xilinx XC3S50 FPGA. Of course this can be compiled on whatever brand of logic you prefer, I've not used any proprietary/strange (other than local clocks, which are usually discouraged) property. Of course this is only a piece of the whole thing but it is the starting point. I combine 4 of these to get a 2.5nS single shot resolution, driven by 4 phases of the 100MHz clock derived from the XC3S50 clock manager. The 144pin XC3S50 can be soldered by hand, not so easy but can be done. Better get an FPGA evaluation board. On Mon, May 7, 2012 at 11:27 PM, Thomas S. Knutsen la3...@gmail.com wrote: Hello. Thanks for publishing the VHDL code. What kind of device do you suggest for incorporating this? perhaps one that can be soldered by humans (no BGA). My only experience with FPGA is the Altera DE2 board we use at school. 73 de Thomas LA3PNA. 2012/5/7 Azelio Boriani azelio.bori...@screen.it OK, so 1 PPS GPS to Rb - need a TIC; 10MHz Rb to OCXO - need a PLL. Are you interested in an all digital 10nS single shot TIC that gives you a 2's complement number (negative at the left of the GPS PPS and positive at the right)? Here it is. This is my TIC, I use it on all my GPSDOs. LIBRARY IEEE; USE IEEE.STD_LOGIC_1164.ALL; USE IEEE.STD_LOGIC_UNSIGNED.ALL; ENTITY PPSPSI IS PORT (PPSTIEOut: OUT std_logic_vector (23 downto 0); PPSInA, PPSInB, Clock100, Clock20: IN std_logic); END ENTITY PPSPSI; ARCHITECTURE RippleCounter OF PPSPSI IS SIGNAL PPSPhaseCntAB, PPSPhaseCntBA: std_logic_vector (22 downto 0); SIGNAL PPSPhaseLtc: std_logic_vector (23 downto 0); SIGNAL PPSADlyed, PPSBDlyed: std_logic_vector (4 downto 0); SIGNAL PPSGateAB, PPSGateBA, PPSLtcA, PPSRstA, PPSLtcB, PPSRstB, StopCntAB, StopCntBA: std_logic; SIGNAL RstGateAB, RstGateBA, OvrLtcAB, OvrLtcBA, PPSLtcA1, PPSLtcB1, PPSA2BSign: std_logic; BEGIN PPSAtoBSign: PROCESS --Sign will be 1 when A leads B (that is the TIE is negative) BEGIN WAIT UNTIL PPSInB'EVENT AND PPSInB='1'; PPSA2BSign= PPSInA; END PROCESS PPSAtoBSign; PPSAtoBGate: PROCESS (PPSInA, RstGateAB) BEGIN IF RstGateAB='1' THEN PPSGateAB= '0'; ELSIF PPSInA'EVENT AND PPSInA='1' THEN PPSGateAB= '1'; END IF; END PROCESS PPSAtoBGate; PPSBtoAGate: PROCESS (PPSInB, RstGateBA) BEGIN IF RstGateBA='1' THEN PPSGateBA= '0'; ELSIF PPSInB'EVENT AND PPSInB='1' THEN PPSGateBA= '1'; END IF; END PROCESS PPSBtoAGate; PPSADelay: PROCESS BEGIN WAIT UNTIL Clock20'EVENT AND Clock20='1'; PPSADlyed= PPSADlyed (3 downto 0)PPSInA; END PROCESS PPSADelay; PPSBDelay: PROCESS BEGIN WAIT UNTIL Clock20'EVENT AND Clock20='1'; PPSBDlyed= PPSBDlyed (3 downto 0)PPSInB; END PROCESS PPSBDelay; PPSPhaseErrAB0: PROCESS (Clock100, PPSRstB) --Phase error counter bit 0 clocked by the gated 100MHz BEGIN IF PPSRstB='1' THEN PPSPhaseCntAB (0)= '1'; ELSIF Clock100'EVENT AND Clock100='1' THEN IF PPSGateAB='1' AND StopCntAB='0' THEN PPSPhaseCntAB (0)= NOT PPSPhaseCntAB (0); END IF; END IF; END PROCESS PPSPhaseErrAB0; PPSPhaseErrAB: FOR I IN 1 TO 22 GENERATE PPSPhaseErrABi: PROCESS (PPSPhaseCntAB (I-1), PPSRstB) --Phase error counter bit 1 BEGIN IF PPSRstB='1' THEN PPSPhaseCntAB (I)= '1'; ELSIF PPSPhaseCntAB (I-1)'EVENT AND PPSPhaseCntAB (I-1)='1' THEN PPSPhaseCntAB (I)= NOT PPSPhaseCntAB (I); END IF; END PROCESS PPSPhaseErrABi; END GENERATE PPSPhaseErrAB; PPSPhaseErrBA0: PROCESS (Clock100, PPSRstA) --Phase error counter bit 0 clocked by the gated 100MHz BEGIN IF PPSRstA='1' THEN PPSPhaseCntBA (0)= '0'; ELSIF Clock100'EVENT AND Clock100='1' THEN IF PPSGateBA='1' AND StopCntBA='0' THEN PPSPhaseCntBA (0)= NOT PPSPhaseCntBA (0); END IF; END IF; END PROCESS PPSPhaseErrBA0; PPSPhaseErrBA: FOR I IN 1 TO 22 GENERATE PPSPhaseErrBAi: PROCESS (PPSPhaseCntBA (I-1), PPSRstA) --Phase error down counter BEGIN IF PPSRstA='1' THEN PPSPhaseCntBA (I)= '0'; ELSIF PPSPhaseCntBA (I-1)'EVENT AND PPSPhaseCntBA (I-1)='0' THEN PPSPhaseCntBA (I)= NOT PPSPhaseCntBA (I); END IF; END PROCESS PPSPhaseErrBAi; END GENERATE PPSPhaseErrBA; StopCntAB= '1' WHEN PPSPhaseCntAB (22 downto 1)=00 ELSE '0'; StopCntBA= '1' WHEN PPSPhaseCntBA (22 downto 1)=11 ELSE '0'; PPSPhaseLtc= '0'PPSPhaseCntBA WHEN PPSLtcA='1' AND PPSA2BSign='0' AND StopCntBA='0' ELSE '1'PPSPhaseCntAB WHEN PPSLtcB='1' AND PPSA2BSign='1' AND StopCntAB='0' ELSE PPSPhaseLtc; OvrLtcAB= StopCntAB WHEN PPSLtcB1='1' ELSE OvrLtcAB; OvrLtcBA= StopCntBA WHEN PPSLtcA1='1' ELSE OvrLtcBA; RstGateAB= '1' WHEN PPSInB='1' AND PPSBDlyed (1)='0' ELSE '0'; RstGateBA= '1' WHEN PPSInA='1' AND PPSADlyed (1)='0' ELSE '0'; PPSLtcA= '1' WHEN PPSADlyed=00011 ELSE '0'; PPSLtcA1= '1' WHEN PPSADlyed=1 ELSE '0'; --To be used by the terminal count value PPSRstA= '1' WHEN PPSADlyed=0 ELSE '0'; PPSLtcB= '1' WHEN PPSBDlyed=00011 ELSE '0'; PPSLtcB1= '1' WHEN PPSBDlyed=1 ELSE '0'; --To be used by the terminal
[time-nuts] Faster than light of a different type
This is a note on a site about some experiments to transmit information faster than light. It fiddles with some definitions in the speed of light restrictions in quantum theory. the reason I am posting here is that it used Rubidium beams. The actual publications may be of interest to those who use such around here. Sadly the actual information is behind a paywall. Jim http://www.theregister.co.uk/2012/05/07/faster_than_light_quantum/ ___ 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] Interesting paper: Don't GPSD' your Rb...
Well, so given the goal (stability at tau, for example) find the best measure and adjust rates (maybe they are not the same) given the oscillator-to-be-disciplined characteristics. On Mon, May 7, 2012 at 11:44 PM, Magnus Danielson mag...@rubidium.dyndns.org wrote: On 05/07/2012 10:59 PM, Azelio Boriani wrote: Yes, interesting, now I realize... but: the larger the deviation becomes and lower frequency it will have... and both makes itharder to suppress by filtering. Filtering at what level? Lengthen the sampling time? The average build up? That is, now I'm not aware and think that I have to correct as slowly as possible because I think that the oscillator has to be disturbed to a minimum. Then I see low frequency large deviations, so I think, OK, I have to average longer to account for. Is this the filtering you are referring to? So that one ends up increasing the slowness of the system getting only very slow frequency very large deviations. Thanks for the help If you have a little frequency error the longer you wait to do any adjustment the larger phase-deviation that frequency error will result in. If you sample to seldom, then you rely on your DAC resolution and stability inbetween your samples, the clock will essentially be in hold-over. If this is 1 ms, 1 s or 1000 s will make a difference. That relates to sampling rate, which puts a limit to the loop bandwidth you can have. But my main reaction was to the sample-rate vs. measure and adjust rate (i.e. sample rate), and I wanted to point out that there is a merit in sampling (much) faster. The modulation waveform is only to illustrate the averaging behaviour. 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.
[time-nuts] The Elusive 74AC175PC
Summary: I found some, 50 or so, 20 cents each. Contact me off-list (at k6...@arrl.net) if you are interested. The longer version: My travels had me near a surplus place I hadn't visited in a while. Wandering the aisles, I thought to myself, Self, there's a part we need for the PICTIC II -- what was it? A quick Google search, and wandering down the aisles... Ah, the elusive 74AC175PC! Probably 50 or so, in tubes. I picked up a tube of 9 for 20 cents each. National Semiconductor logo, 16 pin DIP, date code P9312AB so not quite as old as my kids, leads all shiny and bright. I still need programmed PICs for my boards. Horse trading, anyone? Let me know if you need some of these parts. 73, Bob K6RTM in sunny Silicon Valley preferred email: k6...@arrl.net ___ 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] The Elusive 74AC175PC
great find! the best I could find was $2 at qty 100 On Mon, May 7, 2012 at 3:49 PM, Bob Martin k6...@comcast.net wrote: Summary: I found some, 50 or so, 20 cents each. Contact me off-list (at k6...@arrl.net) if you are interested. The longer version: My travels had me near a surplus place I hadn't visited in a while. Wandering the aisles, I thought to myself, Self, there's a part we need for the PICTIC II -- what was it? A quick Google search, and wandering down the aisles... Ah, the elusive 74AC175PC! Probably 50 or so, in tubes. I picked up a tube of 9 for 20 cents each. National Semiconductor logo, 16 pin DIP, date code P9312AB so not quite as old as my kids, leads all shiny and bright. I still need programmed PICs for my boards. Horse trading, anyone? Let me know if you need some of these parts. 73, Bob K6RTM in sunny Silicon Valley preferred email: k6...@arrl.net ___ 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. -- --Eric _ Eric Garner ___ 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] Oh dear
Wow! $1260 for a 4' power cord, but wait, there's more... It was named 'Power Cord of the Year'. Mike On 5/7/2012 9:39 AM, Burt I. Weiner wrote: A friend of mine signed me up for a catalog from the Audio Advisor. He said I deserved this - I was afraid to ask what he meant by that! Spend a few minutes looking over this site: http://www.audioadvisor.com/ Be sure to check out their Power cords at: http://home-audio.audioadvisor.com/search?w=Power+Cords Burt, K6OQK From: Rob Kimberley robkimber...@btinternet.com To: 'Discussion of precise time and frequency measurement' time-nuts@febo.com Subject: Re: [time-nuts] Oh dear An old saying: a fool and his money are often parted. Sums things up nicely I feel. Rob Kimberley Burt I. Weiner Associates Broadcast Technical Services Glendale, California U.S.A. b...@att.net www.biwa.cc K6OQK ___ 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] Motorola UT+ Oncore GPS Timing Receiver 1pps R5122U1154
Hi, Guys I just purchased two Motorola UT+ Oncore GPS Timing Receiver 1pps R5122U1154 pcb's. Does anyone have any information such as a schematic or software on these. Thankyou Ken Kubick kenkub...@hotmail.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Motorola UT+ Oncore GPS Timing Receiver 1pps R5122U1154
As usual you can find the UT+ manual but don't expect to find any commercial GPS receiver schematic. Try here: www.tapr.org/gps_oncoreut.html On Tue, May 8, 2012 at 1:01 AM, Ken Kubick kenkub...@hotmail.com wrote: Hi, Guys I just purchased two Motorola UT+ Oncore GPS Timing Receiver 1pps R5122U1154 pcb's. Does anyone have any information such as a schematic or software on these. Thankyou Ken Kubick kenkub...@hotmail.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Oh dear - can we please close this thread
Guys, this thread and the un-countable emails it has generated so far is the exact type of discussion that TVB just sent out an email about that should not be on time nuts. bye, Said In a message dated 5/7/2012 16:00:54 Pacific Daylight Time, mbla...@satx.rr.com writes: Wow! $1260 for a 4' power cord, but wait, there's more... It was named 'Power Cord of the Year'. Mike On 5/7/2012 9:39 AM, Burt I. Weiner wrote: A friend of mine signed me up for a catalog from the Audio Advisor. He said I deserved this - I was afraid to ask what he meant by that! Spend a few minutes looking over this site: http://www.audioadvisor.com/ Be sure to check out their Power cords at: http://home-audio.audioadvisor.com/search?w=Power+Cords Burt, K6OQK From: Rob Kimberley robkimber...@btinternet.com To: 'Discussion of precise time and frequency measurement' time-nuts@febo.com Subject: Re: [time-nuts] Oh dear An old saying: a fool and his money are often parted. Sums things up nicely I feel. Rob Kimberley Burt I. Weiner Associates Broadcast Technical Services Glendale, California U.S.A. b...@att.net www.biwa.cc ___ 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] Motorola UT+ Oncore GPS Timing Receiver 1pps R5122U1154
On Mon, May 7, 2012 at 4:01 PM, Ken Kubick kenkub...@hotmail.com wrote: Hi, Guys I just purchased two Motorola UT+ Oncore GPS Timing Receiver 1pps R5122U1154 pcb's. Does anyone have any information such as a schematic or software on these. Some good links here http://www.synergy-gps.com/index.php?option=com_contenttask=viewid=35Itemid=60 I've got a user manual and some software if Google doesn't turn up links to same. 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] Faster than light of a different type
So it is not scientific information..just pseudo science.. like I travelled back in Time yesterday !! But then I woke up. Another cold fusion.. Alan G3NYK - Original Message - From: jim s j...@jwsss.com To: time-nuts@febo.com Sent: Monday, May 07, 2012 11:16 PM Subject: [time-nuts] Faster than light of a different type This is a note on a site about some experiments to transmit information faster than light. It fiddles with some definitions in the speed of light restrictions in quantum theory. the reason I am posting here is that it used Rubidium beams. The actual publications may be of interest to those who use such around here. Sadly the actual information is behind a paywall. Jim http://www.theregister.co.uk/2012/05/07/faster_than_light_quantum/ ___ 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] Motorola UT+ Oncore GPS Timing Receiver 1pps R5122U1154
Ken, You can find the UT+ Engineering Notes and the complete UT+/GT+ User's Guide here: http://www.synergy-gps.com/index.php?option=com_contenttask=viewid=35; Itemid=60 We should have the legacy UT+ and M12+ firmware history and Firmware Application Notes up at the same location in a couple of days. Art Sepin -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Ken Kubick Sent: Monday, May 07, 2012 4:01 PM To: Time Nuts Subject: [time-nuts] Motorola UT+ Oncore GPS Timing Receiver 1pps R5122U1154 Hi, Guys I just purchased two Motorola UT+ Oncore GPS Timing Receiver 1pps R5122U1154 pcb's. Does anyone have any information such as a schematic or software on these. Thankyou Ken Kubick kenkub...@hotmail.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Faster than light of a different type
not at all. read the summary, they are playing with group delay. oh and by the way, there is some effect working with cold fusion. we don't know what it is. that's why it's called basic research. if we knew what we were doing it wouldn't be called research one more thing, people need to learn to hit the delete key if they don't like a particular email. get over it. Cliff K6CLS On 2012-05-07 16:13, Alan Melia wrote: So it is not scientific information..just pseudo science.. like I travelled back in Time yesterday !! But then I woke up. Another cold fusion.. Alan G3NYK - Original Message - From: jim sj...@jwsss.com To:time-nuts@febo.com Sent: Monday, May 07, 2012 11:16 PM Subject: [time-nuts] Faster than light of a different type This is a note on a site about some experiments to transmit information faster than light. It fiddles with some definitions in the speed of light restrictions in quantum theory. the reason I am posting here is that it used Rubidium beams. The actual publications may be of interest to those who use such around here. Sadly the actual information is behind a paywall. Jim http://www.theregister.co.uk/2012/05/07/faster_than_light_quantum/ ___ 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] Motorola UT+ Oncore GPS Timing Receiver 1pps R5122U1154
Or here: http://gpsd.berlios.de/vendor-docs/motorola/toc.pdf http://gpsd.berlios.de/vendor-docs/motorola/ch1.pdf http://gpsd.berlios.de/vendor-docs/motorola/ch2.pdf http://gpsd.berlios.de/vendor-docs/motorola/ch3.pdf http://gpsd.berlios.de/vendor-docs/motorola/ch4.pdf http://gpsd.berlios.de/vendor-docs/motorola/ch5.pdf http://gpsd.berlios.de/vendor-docs/motorola/ch6.pdf http://gpsd.berlios.de/vendor-docs/motorola/ch7.pdf and a PDF flowchart describing a procedure for bringing up and testing the OnCore: http://gpsd.berlios.de/vendor-docs/motorola/quikstrt.pdf On Tue, May 8, 2012 at 1:08 AM, Azelio Boriani azelio.bori...@screen.itwrote: As usual you can find the UT+ manual but don't expect to find any commercial GPS receiver schematic. Try here: www.tapr.org/gps_oncoreut.html On Tue, May 8, 2012 at 1:01 AM, Ken Kubick kenkub...@hotmail.com wrote: Hi, Guys I just purchased two Motorola UT+ Oncore GPS Timing Receiver 1pps R5122U1154 pcb's. Does anyone have any information such as a schematic or software on these. Thankyou Ken Kubick kenkub...@hotmail.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Oh dear
On Mon, May 07, 2012 at 08:28:41AM -0700, J. Forster wrote: A crummy crystal oscillator zero beated to WWV is good to 1 in 10E6, a Rb disciplined to GPS maybe 1 in 10E11. Do you seriously think you, or anybody, can hear a pitch difference of 0.001 Hz in the audio range? A quartz crystal is plenty good for any audio application, IMO. -John I completely agree, and far more significant than accuracy is jitter (phase noise) in maybe the tenths of a Hz to thousands of Hz area. This does modulate the sampled sound and perhaps is perceptable at very low levels. BUT Cesium, or Rb buys nothing in respect to phase noise in those ranges... really good quality quartz oscillators have much better close in phase noise than many Rb's or Cesiums... What Cesium and Rb buy is good performance measured over much larger taus... which cannot possibly have any impact on human hearing. -- Dave Emery N1PRE/AE, d...@dieconsulting.com DIE Consulting, Weston, Mass 02493 An empty zombie mind with a forlorn barely readable weatherbeaten 'For Rent' sign still vainly flapping outside on the weed encrusted pole - in celebration of what could have been, but wasn't and is not to be now either. ___ 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] Oh dear
It's kinda a trick question. The important thing is 'before anyone could detect any differences in the sound?' I was involved in making a decision to go with brand A or B speakers in a roughly 1200 seat auditorium. There was a lot of political pressure to choose brand B. IMO, brand A sounded better in all cases, except possibly for some specially chosen 'high pressure' jazz advocated by fans brand B. So I set up an A/B test. To make the test fair the speakes were colocated and each set of speakers had their own amps and levels were set to exactly the same SPL on pink noise. Nobody but I knew which speakers were on at what time. The test audience selected brand A as the best sound, but eventually brand B was installed. Politics won. Bottom line, when evaluating the claims of audiophools, like you can 'hear the difference', you have to do truly random, blind, tests A/B tests. I doubt that you need anything better than a crummy $2 crystal to clock audio systems. YMMV, -John j...@quikus.com said: Suppose you have a perfect, ideal clock that puts out 'convert' pulses at an exact rate is used to strobe a high precision A/D. Now suppose you add jitter to that perfect clock so that the rate stays the same but time interval between successive pulses varies randomly between P(1-x) and P(1+x). How big would x have to be before anyone could detect any difference in the sound? It's easy enough to work out the right ballpark. Feed a theoretical sine wave into your A/D. Set it to the max amplitude and max frequency that you expect the system to handle. Look at the zero crossing (max slope). How much time does it take for the signal to transition from an output of 0 to an output of 1 (LSB). If your clock if off by that much in time, the analog voltage that you sample will be off by 1 bit. It's a big deal at radar frequencies, less so at audio. You want to make sure that you don't use one of the oscillator packages that has a programmable PLL. Their jitter specs are nasty. -- These are my opinions, not necessarily my employer's. 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] Faster than light of a different type
MMmmm I still thing that NIST should know better it obviously getting near appropriations time I think you call it !! It is not a connector that is loose this time! I may have access to Phys Rev Letters. Alan - Original Message - From: Cliff Sojourner c...@employees.org To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Tuesday, May 08, 2012 12:22 AM Subject: Re: [time-nuts] Faster than light of a different type not at all. read the summary, they are playing with group delay. oh and by the way, there is some effect working with cold fusion. we don't know what it is. that's why it's called basic research. if we knew what we were doing it wouldn't be called research one more thing, people need to learn to hit the delete key if they don't like a particular email. get over it. Cliff K6CLS On 2012-05-07 16:13, Alan Melia wrote: So it is not scientific information..just pseudo science.. like I travelled back in Time yesterday !! But then I woke up. Another cold fusion.. Alan G3NYK - Original Message - From: jim sj...@jwsss.com To:time-nuts@febo.com Sent: Monday, May 07, 2012 11:16 PM Subject: [time-nuts] Faster than light of a different type This is a note on a site about some experiments to transmit information faster than light. It fiddles with some definitions in the speed of light restrictions in quantum theory. the reason I am posting here is that it used Rubidium beams. The actual publications may be of interest to those who use such around here. Sadly the actual information is behind a paywall. Jim http://www.theregister.co.uk/2012/05/07/faster_than_light_quantum/ ___ 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] Motorola UT+ Oncore GPS Timing Receiver 1pps R5122U1154
On 05/08/2012 01:19 AM, Art Sepin wrote: Ken, You can find the UT+ Engineering Notes and the complete UT+/GT+ User's Guide here: http://www.synergy-gps.com/index.php?option=com_contenttask=viewid=35; Itemid=60 We should have the legacy UT+ and M12+ firmware history and Firmware Application Notes up at the same location in a couple of days. Good to see some of that old material re-appearing. Do you have any of the datasheets for the chips? 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] measure zero beat
David, I haven't been following this thread so I suppose it has already been answered, but how are you measuring zero beat? Lee Mushel - Original Message - From: David I. Emery d...@dieconsulting.com To: j...@quikus.com; Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Monday, May 07, 2012 5:37 PM Subject: Re: [time-nuts] Oh dear On Mon, May 07, 2012 at 08:28:41AM -0700, J. Forster wrote: A crummy crystal oscillator zero beated to WWV is good to 1 in 10E6, a Rb disciplined to GPS maybe 1 in 10E11. Do you seriously think you, or anybody, can hear a pitch difference of 0.001 Hz in the audio range? A quartz crystal is plenty good for any audio application, IMO. -John I completely agree, and far more significant than accuracy is jitter (phase noise) in maybe the tenths of a Hz to thousands of Hz area. This does modulate the sampled sound and perhaps is perceptable at very low levels. BUT Cesium, or Rb buys nothing in respect to phase noise in those ranges... really good quality quartz oscillators have much better close in phase noise than many Rb's or Cesiums... What Cesium and Rb buy is good performance measured over much larger taus... which cannot possibly have any impact on human hearing. -- Dave Emery N1PRE/AE, d...@dieconsulting.com DIE Consulting, Weston, Mass 02493 An empty zombie mind with a forlorn barely readable weatherbeaten 'For Rent' sign still vainly flapping outside on the weed encrusted pole - in celebration of what could have been, but wasn't and is not to be now either. ___ 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.
