Re: [time-nuts] State of the art of crystal oscillator measurements
> If the oscillator output is thru the resonator, then at large offsets, > the source impedance is reactive. It can easily have an effective > temperature less than room temperature. If this "source" is then > used with a low noise temperature preamp, it is entirely possible > to go beyond these supposed theoretical limits that are based > on T=300K. Sure, until you try to measure it with a Zo=50R instrument, or otherwise do something that involves putting real power into a load. -- john, KE5FX Miles Design LLC ___ time-nuts mailing 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] State of the art of crystal oscillator measurements
On 8/11/2016 3:47 PM, John Miles wrote: Right, I'm speaking specifically of L(f). The device being driven by the oscillator doesn't care about the NF of the driver stage, only what a PN analyzer would measure at the output jack. For any 50-ohm source, the practical L(f) floor is -177 dBm/Hz - the carrier power in dBm. No oscillator with an output of 0 dBm can be quieter than -177 dBc/Hz at any offset, but an oscillator that puts out +20 dBm could approach -197 dBc/Hz. Given a proverbial black box containing a +17 dBm oscillator that measures -195 dBc/Hz at 100 kHz, the interesting question is, "What's in the box?" There could be a passive resonator that's shaving off the broadband noise after the last active stage without contributing additive noise of its own. Another possibility might be cross-spectral collapse due to correlated thermal noise from the splitter. -- john, KE5FX Miles Design LLC If the oscillator output is thru the resonator, then at large offsets, the source impedance is reactive. It can easily have an effective temperature less than room temperature. If this "source" is then used with a low noise temperature preamp, it is entirely possible to go beyond these supposed theoretical limits that are based on T=300K. Rick ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] State of the art of crystal oscillator measurements
-177dBm /Hz at 300 deg SSB phase noise is correct, not because AM/ FM but Single Sideband Energy . In my last QEX paper I showed the measured AM and FM levels and how to calculate them. 73 de Ulrich xx In a message dated 8/11/2016 9:00:11 P.M. Eastern Daylight Time, mfe...@eozinc.com writes: That is interesting. We always used -174 and not -177 as it was concluded that at those low levels AM and PM noise are not discernible, so, the total noise density per Hz was -174. This must be relatively new since I worked in industry. We had a bunch of PhDs from Lincoln helping as well and they always used -174. This sounds like one of those instrument manufacturers gimmick to make the numbers look better :). Your last statement is why I started to question the claims initially. - Mike Mike B. Feher, EOZ Inc. 89 Arnold Blvd. Howell, NJ, 07731 732-886-5960 office 908-902-3831 cell -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of John Miles Sent: Thursday, August 11, 2016 7:57 PM To: 'Discussion of precise time and frequency measurement' Subject: Re: [time-nuts] State of the art of crystal oscillator measurements -177 = the -174 dBm/Hz SSB thermal noise floor at 25C, less 3 dB to account for the usual assumption that half of it is AM, half PM. dBm/Hz is obviously equivalent to dBc/Hz for a 0 dBm carrier. Anyone who claims to measure noise in a 1 Hz bandwidth below -177 dBm/Hz at room temperature is either doing something wrong somewhere, or doing something amazing somewhere. -- john, KE5FX Miles Design LLC > -Original Message- > From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Mike > Feher > Sent: Thursday, August 11, 2016 4:15 PM > To: 'Discussion of precise time and frequency measurement' > Subject: Re: [time-nuts] State of the art of crystal oscillator > measurements > > That is why I asked what the Po was. Where did the 177 come from? L(f) > is single sided. This is not my first "rodeo" in these matters. 73 - > Mike > > Mike B. Feher, EOZ Inc. > 89 Arnold Blvd. > Howell, NJ, 07731 > 732-886-5960 office > 908-902-3831 cell > ___ time-nuts mailing 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] State of the art of crystal oscillator measurements
That is interesting. We always used -174 and not -177 as it was concluded that at those low levels AM and PM noise are not discernible, so, the total noise density per Hz was -174. This must be relatively new since I worked in industry. We had a bunch of PhDs from Lincoln helping as well and they always used -174. This sounds like one of those instrument manufacturers gimmick to make the numbers look better :). Your last statement is why I started to question the claims initially. - Mike Mike B. Feher, EOZ Inc. 89 Arnold Blvd. Howell, NJ, 07731 732-886-5960 office 908-902-3831 cell -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of John Miles Sent: Thursday, August 11, 2016 7:57 PM To: 'Discussion of precise time and frequency measurement' Subject: Re: [time-nuts] State of the art of crystal oscillator measurements -177 = the -174 dBm/Hz SSB thermal noise floor at 25C, less 3 dB to account for the usual assumption that half of it is AM, half PM. dBm/Hz is obviously equivalent to dBc/Hz for a 0 dBm carrier. Anyone who claims to measure noise in a 1 Hz bandwidth below -177 dBm/Hz at room temperature is either doing something wrong somewhere, or doing something amazing somewhere. -- john, KE5FX Miles Design LLC > -Original Message- > From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Mike > Feher > Sent: Thursday, August 11, 2016 4:15 PM > To: 'Discussion of precise time and frequency measurement' > Subject: Re: [time-nuts] State of the art of crystal oscillator > measurements > > That is why I asked what the Po was. Where did the 177 come from? L(f) > is single sided. This is not my first "rodeo" in these matters. 73 - > Mike > > Mike B. Feher, EOZ Inc. > 89 Arnold Blvd. > Howell, NJ, 07731 > 732-886-5960 office > 908-902-3831 cell > ___ time-nuts mailing 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] State of the art of crystal oscillator measurements
-177 = the -174 dBm/Hz SSB thermal noise floor at 25C, less 3 dB to account for the usual assumption that half of it is AM, half PM. dBm/Hz is obviously equivalent to dBc/Hz for a 0 dBm carrier. Anyone who claims to measure noise in a 1 Hz bandwidth below -177 dBm/Hz at room temperature is either doing something wrong somewhere, or doing something amazing somewhere. -- john, KE5FX Miles Design LLC > -Original Message- > From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Mike > Feher > Sent: Thursday, August 11, 2016 4:15 PM > To: 'Discussion of precise time and frequency measurement' > Subject: Re: [time-nuts] State of the art of crystal oscillator measurements > > That is why I asked what the Po was. Where did the 177 come from? L(f) is > single sided. This is not my first "rodeo" in these matters. 73 - Mike > > Mike B. Feher, EOZ Inc. > 89 Arnold Blvd. > Howell, NJ, 07731 > 732-886-5960 office > 908-902-3831 cell > ___ time-nuts mailing 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] State of the art of crystal oscillator measurements
Good point, the 'milliwatt' part of 'dBm' takes the E^2/R part out of the math. If we were speaking of dBv/Hz, the system Zo would need to be considered to determine the power. -- john, KE5FX Miles Design LLC > -Original Message- > From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Richard > (Rick) Karlquist > Sent: Thursday, August 11, 2016 3:01 PM > To: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] State of the art of crystal oscillator measurements > > Zo doesn't matter for these purposes. > dBm works just as well for 75 ohm systems. > ___ time-nuts mailing 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] State of the art of crystal oscillator measurements
That is why I asked what the Po was. Where did the 177 come from? L(f) is single sided. This is not my first "rodeo" in these matters. 73 - Mike Mike B. Feher, EOZ Inc. 89 Arnold Blvd. Howell, NJ, 07731 732-886-5960 office 908-902-3831 cell -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of John Miles Sent: Thursday, August 11, 2016 4:22 PM To: 'Discussion of precise time and frequency measurement' Subject: Re: [time-nuts] State of the art of crystal oscillator measurements Remember that L(f) is expressed in dBc/Hz, not dBm/Hz. If it were dBm/Hz, then kT would be the limit. But in dBc/Hz terms, the limit is 177 + the DUT's output power in dBm. Assuming a 50 ohm system, of course. -- john, KE5FX Miles Design LLC > -Original Message- > From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Mike > Feher > Sent: Thursday, August 11, 2016 12:51 PM > To: 'Discussion of precise time and frequency measurement'; > ka2...@aol.com; t...@leapsecond.com > Cc: enrico.rubi...@gmail.com > Subject: Re: [time-nuts] State of the art of crystal oscillator > measurements > > kT is indeed relevant for a physical implementation. - Mike > > Mike B. Feher, EOZ Inc. > 89 Arnold Blvd. > Howell, NJ, 07731 > 732-886-5960 office > 908-902-3831 cell ___ time-nuts mailing 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] State of the art of crystal oscillator measurements
Values of kT at 25°C (298 K) Units kT = 4.11×10−21 _J_ (https://en.wikipedia.org/wiki/Joule) kT = 4.114 pN⋅nm kT = 9.83×10−22 _cal_ (https://en.wikipedia.org/wiki/Calorie) kT = 25.7 _meV_ (https://en.wikipedia.org/wiki/Electron-volt)Related quantities kT/hc = 200 cm-1 kT/e = 25.7 _mV_ (https://en.wikipedia.org/wiki/Volt) RT = kT ⋅ _NA_ (https://en.wikipedia.org/wiki/Avogadro's_number) = 2.479 _kJ⋅mol-1_ (https://en.wikipedia.org/wiki/Joule_per_mole) u = 0.593 _kcal⋅mol−1_ (https://en.wikipedia.org/wiki/Kilocalorie_per_mole) _h_ (https://en.wikipedia.org/wiki/Planck_constant) /kT = 0.16 _ps_ (https://en.wikipedia.org/wiki/Picosecond) In a message dated 8/11/2016 7:02:13 P.M. Eastern Daylight Time, j...@miles.io writes: Right, I'm speaking specifically of L(f). The device being driven by the oscillator doesn't care about the NF of the driver stage, only what a PN analyzer would measure at the output jack. For any 50-ohm source, the practical L(f) floor is -177 dBm/Hz - the carrier power in dBm. No oscillator with an output of 0 dBm can be quieter than -177 dBc/Hz at any offset, but an oscillator that puts out +20 dBm could approach -197 dBc/Hz. Given a proverbial black box containing a +17 dBm oscillator that measures -195 dBc/Hz at 100 kHz, the interesting question is, "What's in the box?" There could be a passive resonator that's shaving off the broadband noise after the last active stage without contributing additive noise of its own. Another possibility might be cross-spectral collapse due to correlated thermal noise from the splitter. -- john, KE5FX Miles Design LLC > -Original Message- > From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of KA2WEU-- > - via time-nuts > Sent: Thursday, August 11, 2016 2:37 PM > To: time-nuts@febo.com > Subject: Re: [time-nuts] State of the art of crystal oscillator measurements > > NO, the maximum possible noise dynamic range is ( 177 + Pout) [dBm] - > Transistor large signal NF ( dB), > the signal to noise ration is dimensionless > ___ time-nuts mailing 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] State of the art of crystal oscillator measurements
Right, I'm speaking specifically of L(f). The device being driven by the oscillator doesn't care about the NF of the driver stage, only what a PN analyzer would measure at the output jack. For any 50-ohm source, the practical L(f) floor is -177 dBm/Hz - the carrier power in dBm. No oscillator with an output of 0 dBm can be quieter than -177 dBc/Hz at any offset, but an oscillator that puts out +20 dBm could approach -197 dBc/Hz. Given a proverbial black box containing a +17 dBm oscillator that measures -195 dBc/Hz at 100 kHz, the interesting question is, "What's in the box?" There could be a passive resonator that's shaving off the broadband noise after the last active stage without contributing additive noise of its own. Another possibility might be cross-spectral collapse due to correlated thermal noise from the splitter. -- john, KE5FX Miles Design LLC > -Original Message- > From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of KA2WEU-- > - via time-nuts > Sent: Thursday, August 11, 2016 2:37 PM > To: time-nuts@febo.com > Subject: Re: [time-nuts] State of the art of crystal oscillator measurements > > NO, the maximum possible noise dynamic range is ( 177 + Pout) [dBm] - > Transistor large signal NF ( dB), > the signal to noise ration is dimensionless > ___ time-nuts mailing 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] State of the art of crystal oscillator measurements
Zo doesn't matter for these purposes. dBm works just as well for 75 ohm systems. On 8/11/2016 1:22 PM, John Miles wrote: Remember that L(f) is expressed in dBc/Hz, not dBm/Hz. If it were dBm/Hz, then kT would be the limit. But in dBc/Hz terms, the limit is 177 + the DUT's output power in dBm. Assuming a 50 ohm system, of course. -- john, KE5FX Miles Design LLC ___ time-nuts mailing 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] State of the art of crystal oscillator measurements
Hi The gotcha is that you don’t *have* to have a 50 ohm system. An output stage with a narrow band tuned tank is one example of a very “not 50 ohms” system. There is also a whole debate around the “is 50 ohm source into 50 ohm load really 25 ohms”. That will give you a 3 db delta to bet beers about. The 3 db split of thermal noise between AM noise and PM noise is fairly well accepted, but it still can be challenged. So is the floor -174 - 3 = -177 or is it something else …. If we have a -195.4 dbc/ Hz oscillator that puts out < 18 dbm in a 50 ohm system it’s not -177 or it’s not a 50 ohm system. Bob > On Aug 11, 2016, at 4:47 PM, John Miles wrote: > > Or rather -(177+DUT output power in dBm). The minus sign makes the > difference between the thermal floor and a nuclear war! > > -- john, KE5FX > Miles Design LLC > >> Remember that L(f) is expressed in dBc/Hz, not dBm/Hz. If it were dBm/Hz, >> then kT would be the limit. But in dBc/Hz terms, the limit is 177 + the >> DUT's >> output power in dBm. > > > ___ > time-nuts mailing 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] State of the art of crystal oscillator measurements
I am quite intrigued by two things here: 1. What improvements were made to the instruments, and 2. What were the instrument settings and test setups? Thanks. Tom Holmes, N8ZM -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of KA2WEU--- via time-nuts Sent: Thursday, August 11, 2016 4:34 PM To: time-nuts@febo.com Subject: Re: [time-nuts] State of the art of crystal oscillator measurements See below In a message dated 8/11/2016 4:30:47 P.M. Eastern Daylight Time, j...@miles.io writes: Remember that L(f) is expressed in dBc/Hz, not dBm/Hz. If it were dBm/Hz, then kT would be the limit. But in dBc/Hz terms, the limit is 177 + the DUT's output power in dBm - transistor large signal NF in dB . Assuming a 50 ohm system, of course. -- john, KE5FX Miles Design LLC > -Original Message- > From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Mike > Feher > Sent: Thursday, August 11, 2016 12:51 PM > To: 'Discussion of precise time and frequency measurement'; > ka2...@aol.com; t...@leapsecond.com > Cc: enrico.rubi...@gmail.com > Subject: Re: [time-nuts] State of the art of crystal oscillator measurements > > kT is indeed relevant for a physical implementation. - Mike > > Mike B. Feher, EOZ Inc. > 89 Arnold Blvd. > Howell, NJ, 07731 > 732-886-5960 office > 908-902-3831 cell ___ time-nuts mailing 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] State of the art of crystal oscillator measurements
NO, the maximum possible noise dynamic range is ( 177 + Pout) [dBm] - Transistor large signal NF ( dB), the signal to noise ration is dimensionless In a message dated 8/11/2016 5:00:43 P.M. Eastern Daylight Time, j...@miles.io writes: Or rather -(177+DUT output power in dBm). The minus sign makes the difference between the thermal floor and a nuclear war! -- john, KE5FX Miles Design LLC > Remember that L(f) is expressed in dBc/Hz, not dBm/Hz. If it were dBm/Hz, > then kT would be the limit. But in dBc/Hz terms, the limit is 177 + the DUT's > output power in dBm. ___ time-nuts mailing 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] State of the art of crystal oscillator measurements
Or rather -(177+DUT output power in dBm). The minus sign makes the difference between the thermal floor and a nuclear war! -- john, KE5FX Miles Design LLC > Remember that L(f) is expressed in dBc/Hz, not dBm/Hz. If it were dBm/Hz, > then kT would be the limit. But in dBc/Hz terms, the limit is 177 + the DUT's > output power in dBm. ___ time-nuts mailing 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] State of the art of crystal oscillator measurements
See below In a message dated 8/11/2016 4:30:47 P.M. Eastern Daylight Time, j...@miles.io writes: Remember that L(f) is expressed in dBc/Hz, not dBm/Hz. If it were dBm/Hz, then kT would be the limit. But in dBc/Hz terms, the limit is 177 + the DUT's output power in dBm - transistor large signal NF in dB . Assuming a 50 ohm system, of course. -- john, KE5FX Miles Design LLC > -Original Message- > From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Mike > Feher > Sent: Thursday, August 11, 2016 12:51 PM > To: 'Discussion of precise time and frequency measurement'; > ka2...@aol.com; t...@leapsecond.com > Cc: enrico.rubi...@gmail.com > Subject: Re: [time-nuts] State of the art of crystal oscillator measurements > > kT is indeed relevant for a physical implementation. - Mike > > Mike B. Feher, EOZ Inc. > 89 Arnold Blvd. > Howell, NJ, 07731 > 732-886-5960 office > 908-902-3831 cell ___ time-nuts mailing 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] State of the art of crystal oscillator measurements
Remember that L(f) is expressed in dBc/Hz, not dBm/Hz. If it were dBm/Hz, then kT would be the limit. But in dBc/Hz terms, the limit is 177 + the DUT's output power in dBm. Assuming a 50 ohm system, of course. -- john, KE5FX Miles Design LLC > -Original Message- > From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Mike > Feher > Sent: Thursday, August 11, 2016 12:51 PM > To: 'Discussion of precise time and frequency measurement'; > ka2...@aol.com; t...@leapsecond.com > Cc: enrico.rubi...@gmail.com > Subject: Re: [time-nuts] State of the art of crystal oscillator measurements > > kT is indeed relevant for a physical implementation. - Mike > > Mike B. Feher, EOZ Inc. > 89 Arnold Blvd. > Howell, NJ, 07731 > 732-886-5960 office > 908-902-3831 cell ___ time-nuts mailing 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] State of the art of crystal oscillator measurements
kT is indeed relevant for a physical implementation. - Mike Mike B. Feher, EOZ Inc. 89 Arnold Blvd. Howell, NJ, 07731 732-886-5960 office 908-902-3831 cell -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Richard (Rick) Karlquist Sent: Thursday, August 11, 2016 1:40 PM To: Discussion of precise time and frequency measurement; ka2...@aol.com; t...@leapsecond.com Cc: enrico.rubi...@gmail.com Subject: Re: [time-nuts] State of the art of crystal oscillator measurements On 8/11/2016 5:01 AM, Mike Feher wrote: > This may be a naive question, but, how can you achieve results that > are so close to, and sometimes at further out are below kT? Thanks & > 73 - Mike > Mike B. Feher, EOZ Inc. > kT per see is not the relevant parameter. It is the ratio between kT and signal level that determines the limit on phase noise. Also, when you extract an oscillator signal through the resonator, then at offsets from the carrier, the resonator filters out noise and the output noise can be way below kT. Ulrich first published on this in 1977. Earliest reference I know of. I actually remember reading it in 1977. The old HP608 signal generator routinely produced far out phase noise floor well below kT. AFAIK, for this particular spec, it better than any other signal generator ever built. What's the secret? It has a tracking POST-selector filter that follows the oscillator when you turn the mechanical tuning knob. There is a little tracking adjustment knob to peak it. Not really magic. Rick ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing 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] State of the art of crystal oscillator measurements
On 8/11/2016 5:01 AM, Mike Feher wrote: This may be a naive question, but, how can you achieve results that are so close to, and sometimes at further out are below kT? Thanks & 73 - Mike Mike B. Feher, EOZ Inc. kT per see is not the relevant parameter. It is the ratio between kT and signal level that determines the limit on phase noise. Also, when you extract an oscillator signal through the resonator, then at offsets from the carrier, the resonator filters out noise and the output noise can be way below kT. Ulrich first published on this in 1977. Earliest reference I know of. I actually remember reading it in 1977. The old HP608 signal generator routinely produced far out phase noise floor well below kT. AFAIK, for this particular spec, it better than any other signal generator ever built. What's the secret? It has a tracking POST-selector filter that follows the oscillator when you turn the mechanical tuning knob. There is a little tracking adjustment knob to peak it. Not really magic. Rick ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] State of the art of crystal oscillator measurements
Ulrich - This may be a naive question, but, how can you achieve results that are so close to, and sometimes at further out are below kT? Thanks & 73 - Mike Mike B. Feher, EOZ Inc. === .. by reducing T? David -- SatSignal Software - Quality software written to your requirements Web: http://www.satsignal.eu Email: david-tay...@blueyonder.co.uk Twitter: @gm8arv ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] State of the art of crystal oscillator measurements
Ulrich - This may be a naive question, but, how can you achieve results that are so close to, and sometimes at further out are below kT? Thanks & 73 - Mike Mike B. Feher, EOZ Inc. 89 Arnold Blvd. Howell, NJ, 07731 732-886-5960 office 908-902-3831 cell From: ka2...@aol.com [mailto:ka2...@aol.com] Sent: Thursday, August 11, 2016 7:03 AM To: time-nuts@febo.com; t...@leapsecond.com Cc: enrico.rubi...@gmail.com; mfe...@eozinc.com Subject: Re: [time-nuts] State of the art of crystal oscillator measurements Good morning, the difference between the two phase noise FWSP systems is the lower noise internal 10 MHz reference crystal oscillator (optimized ) as well as also some of the internal FSWP circuits custom optimized . The output power was 17 dBm, but we also have build one oscillator with 12 dBm output power and noise similar values. This is part of a PhD project which I supervise . For values so close to the carrier you need a very low noise power supply and a well shielded Faraday cage . The measurement with ca 100 correlation took about 2 hours. Also the heating circuit needs to be low noise and well decoupled . The 100 Hz value of the better analyzer seems suspicious , It needs to be further investigated. All very exciting and time consuming . Ulrich In a message dated 8/10/2016 11:02:25 P.M. Eastern Daylight Time, mfe...@eozinc.com writes: These seem extremely fantastic results for a 100 MHz oscillator. I am curious what the Po of the oscillators are Regards - Mike Mike B. Feher, EOZ Inc. 89 Arnold Blvd. Howell, NJ, 07731 732-886-5960 office 908-902-3831 cell -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Tom Van Baak Sent: Wednesday, August 10, 2016 9:19 PM To: Discussion of precise time and frequency measurement Cc: enrico.rubi...@gmail.com Subject: Re: [time-nuts] State of the art of crystal oscillator measurements Attached is a GIF of the table Ulrich wants to share. Note time-nuts is a plain text mailing list so any rtf or html formatting is discarded. On the bright side, PDF or data or image attachments are allowed with no problem. /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. ___ time-nuts mailing 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] State of the art of crystal oscillator measurements
Good morning, the difference between the two phase noise FWSP systems is the lower noise internal 10 MHz reference crystal oscillator (optimized ) as well as also some of the internal FSWP circuits custom optimized . The output power was 17 dBm, but we also have build one oscillator with 12 dBm output power and noise similar values. This is part of a PhD project which I supervise .For values so close to the carrier you need a very low noise power supply and a well shielded Faraday cage . The measurement with ca 100 correlation took about 2 hours. Also the heating circuit needs to be low noise and well decoupled . The 100 Hz value of the better analyzer seems suspicious , It needs to be further investigated. All very exciting and time consuming . Ulrich In a message dated 8/10/2016 11:02:25 P.M. Eastern Daylight Time, mfe...@eozinc.com writes: These seem extremely fantastic results for a 100 MHz oscillator. I am curious what the Po of the oscillators are Regards - Mike Mike B. Feher, EOZ Inc. 89 Arnold Blvd. Howell, NJ, 07731 732-886-5960 office 908-902-3831 cell -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Tom Van Baak Sent: Wednesday, August 10, 2016 9:19 PM To: Discussion of precise time and frequency measurement Cc: enrico.rubi...@gmail.com Subject: Re: [time-nuts] State of the art of crystal oscillator measurements Attached is a GIF of the table Ulrich wants to share. Note time-nuts is a plain text mailing list so any rtf or html formatting is discarded. On the bright side, PDF or data or image attachments are allowed with no problem. /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. ___ time-nuts mailing 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] State of the art of crystal oscillator measurements
These seem extremely fantastic results for a 100 MHz oscillator. I am curious what the Po of the oscillators are Regards - Mike Mike B. Feher, EOZ Inc. 89 Arnold Blvd. Howell, NJ, 07731 732-886-5960 office 908-902-3831 cell -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Tom Van Baak Sent: Wednesday, August 10, 2016 9:19 PM To: Discussion of precise time and frequency measurement Cc: enrico.rubi...@gmail.com Subject: Re: [time-nuts] State of the art of crystal oscillator measurements Attached is a GIF of the table Ulrich wants to share. Note time-nuts is a plain text mailing list so any rtf or html formatting is discarded. On the bright side, PDF or data or image attachments are allowed with no problem. /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] State of the art of crystal oscillator measurements
Attached is a GIF of the table Ulrich wants to share. Note time-nuts is a plain text mailing list so any rtf or html formatting is discarded. On the bright side, PDF or data or image attachments are allowed with no problem. /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] State of the art of crystal oscillator measurements
The _time-nuts@febo.com_ (mailto:time-nuts@febo.com) reformatted the offset / phase noise table so it became almost unreadable compared to the original , sorry, Ulrich In a message dated 8/10/2016 8:00:28 P.M. Eastern Daylight Time, time-nuts@febo.com writes: Test Equipment Improvement The measurement of the 100 MHz XO was done on an improved R&S FSWPs. Measured data is in the table below: XO 100 MHz FSWP SN 101143 FSWP SN 101192 Offset Phase Noise in dBc/Hz 0.1 Hz -45.24 -49.11 1 Hz -82.30 -82.33 10 Hz -113.87 -113.74 100 Hz -143.27 -141.61 1 kHz -166.55 -167.26 10 kHz -180.54 -186.91 100 kHz -186.41 -195.43 ___ time-nuts mailing 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.