Hi The only practical way to set the 10811 or 10544 is with a >= 10 turn pot on the EFC. I never have worked out just why there are so many instruments that don’t have a pot on the EFC. Bob > On Nov 4, 2016, at 11:35 AM, Peter Reilley <preilley_454@comcast.net> wrote: > > I gave up on trying to use the GPS 1 PPS signal to calibrate the 10 MHz OCXO's that > I have. The reason that others have pointed out is that the uncorrected 1 PPS > signal from the GPS is has just a little too much a jitter to use it for calibration > with your eye using a scope. If it were sawtooth corrected then it would be better > but you really need a GPS disciplined oscillator. > > Not to be outdone, I brought out a rubidium oscillator that I had put away because > it did not appear to work properly. It only put out a 1 PPS signal and nothing else. > I compared that with the GPS PPS and could get a good comparison on the scope. > The rubidium drifted about 40 nS over 12 hours. So it seemed to be good. > > With that I could adjust the OCXO's in my 5370's. The spec for the HP 5370B with > a HP 10811 OCXO is better than 1 X 10^-10 RMS for 1 sec average. That is, it should > take more than 1,000 seconds for one 10 MHz wave to shift by 360 degrees. That > is very hard to do using the screw adjustment in the OCXO. Even the slightest > movement possible will cause a frequency change greater that is spec'ed. How > do cal labs do it? > > My HP 5370A has a 10544 OCXO which is spec'ed for short term stability of > better than 1 X 10^11 for 1 second. Even better than the 5370B! The adjustment > screw is much coarser and it is not possible to get any better than a few seconds for > one cycle phase shift of the 10 MHz OCXO against the standard. It seems that I can't > get even close to the spec. > > These have been running for a few days. It that enough? > > Pete. > > > > On 11/3/2016 8:20 AM, Peter Reilley wrote: >> I am the proverbial man with too many clocks and I don't know what time it is. >> To correct this situation I have decided to calibrate everything. >> >> I have a HP 5370B, a HP 6370A, and a HP 5328A all with the TCXO option. I also >> have some TCXO modules. I figured that I would calibrate them against my Trimble >> Resolution T GPS receiver. >> >> I put the 1 PPS signal in one channel of my scope and one of the 10 MHz TCXO >> signals in the other channel and look at the phase relationship. The TCXO's are >> already close enough that I should not be out by more than a fraction of a waveform. >> I understand that I have to deal with the 1 PPS without sawtooth correction. >> >> I expected to see the 10 MHz signal bounce around but not move more than 1/2 >> of a wave length. Instead I see the 10 MHz waveform appear steady for a few seconds >> then jump a significant portion of the wave. The jump is too much to be confident >> that I have not slipped one cycle. >> >> Can I do what I am trying to do or am I missing something? >> >> Pete. >> >> _______________________________________________ >> time-nuts mailing 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.

I'm not sure if there is a reason counters don't let you digitally calibrate beyond that, the 10 MHz ref out on the rear panel would still be out of cal. On Fri, Nov 4, 2016 at 1:48 PM, Bob Camp <kb8tq@n1k.org> wrote: > Hi > > The only practical way to set the 10811 or 10544 is with a >= 10 turn pot > on the EFC. I > never have worked out just why there are so many instruments that don’t > have a pot on > the EFC. > > Bob > > > On Nov 4, 2016, at 11:35 AM, Peter Reilley <preilley_454@comcast.net> > wrote: > > > > I gave up on trying to use the GPS 1 PPS signal to calibrate the 10 MHz > OCXO's that > > I have. The reason that others have pointed out is that the > uncorrected 1 PPS > > signal from the GPS is has just a little too much a jitter to use it for > calibration > > with your eye using a scope. If it were sawtooth corrected then it > would be better > > but you really need a GPS disciplined oscillator. > > > > Not to be outdone, I brought out a rubidium oscillator that I had put > away because > > it did not appear to work properly. It only put out a 1 PPS signal and > nothing else. > > I compared that with the GPS PPS and could get a good comparison on the > scope. > > The rubidium drifted about 40 nS over 12 hours. So it seemed to be > good. > > > > With that I could adjust the OCXO's in my 5370's. The spec for the HP > 5370B with > > a HP 10811 OCXO is better than 1 X 10^-10 RMS for 1 sec average. That > is, it should > > take more than 1,000 seconds for one 10 MHz wave to shift by 360 > degrees. That > > is very hard to do using the screw adjustment in the OCXO. Even the > slightest > > movement possible will cause a frequency change greater that is > spec'ed. How > > do cal labs do it? > > > > My HP 5370A has a 10544 OCXO which is spec'ed for short term stability of > > better than 1 X 10^11 for 1 second. Even better than the 5370B! The > adjustment > > screw is much coarser and it is not possible to get any better than a > few seconds for > > one cycle phase shift of the 10 MHz OCXO against the standard. It > seems that I can't > > get even close to the spec. > > > > These have been running for a few days. It that enough? > > > > Pete. > > > > > > > > On 11/3/2016 8:20 AM, Peter Reilley wrote: > >> I am the proverbial man with too many clocks and I don't know what time > it is. > >> To correct this situation I have decided to calibrate everything. > >> > >> I have a HP 5370B, a HP 6370A, and a HP 5328A all with the TCXO > option. I also > >> have some TCXO modules. I figured that I would calibrate them against > my Trimble > >> Resolution T GPS receiver. > >> > >> I put the 1 PPS signal in one channel of my scope and one of the 10 MHz > TCXO > >> signals in the other channel and look at the phase relationship. The > TCXO's are > >> already close enough that I should not be out by more than a fraction > of a waveform. > >> I understand that I have to deal with the 1 PPS without sawtooth > correction. > >> > >> I expected to see the 10 MHz signal bounce around but not move more > than 1/2 > >> of a wave length. Instead I see the 10 MHz waveform appear steady for > a few seconds > >> then jump a significant portion of the wave. The jump is too much to > be confident > >> that I have not slipped one cycle. > >> > >> Can I do what I am trying to do or am I missing something? > >> > >> Pete. > >> > >> _______________________________________________ > >> time-nuts mailing 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. >

Satellite TV (Dish, Direct, etc) has been having trouble for 10 hours or so, sometimes losing some channels and occasionally all of them. Fox News is consistently down, so it could have a human cause, but Space Weather says we have unusual solar activity. I no longer have GPS time receivers, so I wonder how GPS is doing. Thanks for any comments. Bill Hawkins

My simple solution to this was to divide the 1 PPS signal down so the jitter from the uncorrected GPS was a smaller part. Of course then each measurement takes proportionally longer. On Fri, 4 Nov 2016 11:35:59 -0400, you wrote: >I gave up on trying to use the GPS 1 PPS signal to calibrate the 10 MHz >OCXO's that >I have. The reason that others have pointed out is that the >uncorrected 1 PPS >signal from the GPS is has just a little too much a jitter to use it for >calibration >with your eye using a scope. If it were sawtooth corrected then it >would be better >but you really need a GPS disciplined oscillator. > >... > >Pete.

Hi David, Your solution is fine. Most time interval counters can only make 10 or 100 or at most 1000 measurements per second, so what you did is exactly the right thing. When using a divider + TIC nothing is lost and everything is gained. Even 'scopes cannot retrace 1000's of times a second. So using a digital divider is what almost all of us do. What you don't want to get in the habit of doing is comparing 10 MHz (100 ns cycles) against 1 PPS. Why? Because it works most of the time, except when it doesn't. Which is to say a good GPS/1PPS is within +/-50 ns almost all the time, except when it isn't. So it's more robust to phase compare a GPS/1PPS against another 1PPS, or even 1 kHz or 10 kHz, but not 10 MHz. This drastically reduces to practically eliminates chances of cycle slip. It's one reason why the PIC divider chips (or equivalent) are so useful (www.leapsecond.com/pic). /tvb ----- Original Message ----- From: "David" <davidwhess@gmail.com> To: "Discussion of precise time and frequency measurement" <time-nuts@febo.com> Sent: Friday, November 04, 2016 4:30 PM Subject: Re: [time-nuts] Man with too many clocks. > My simple solution to this was to divide the 1 PPS signal down so the > jitter from the uncorrected GPS was a smaller part. Of course then > each measurement takes proportionally longer. > > On Fri, 4 Nov 2016 11:35:59 -0400, you wrote: > >>I gave up on trying to use the GPS 1 PPS signal to calibrate the 10 MHz >>OCXO's that >>I have. The reason that others have pointed out is that the >>uncorrected 1 PPS >>signal from the GPS is has just a little too much a jitter to use it for >>calibration >>with your eye using a scope. If it were sawtooth corrected then it >>would be better >>but you really need a GPS disciplined oscillator. >> >>... >> >>Pete. > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there.

It is a FE-5680B. It is my understanding that these were made in many variations of features but that what features were present or absent could not be known from the model numbers of other external identifying information. This one has the 1 PPS apparently. Pete. On 11/4/2016 1:07 PM, EB4APL wrote: > A bit OT, but regarding your Rb, some units needs to be powered thru 2 > pins, one is used only for the 10 MHz output buffer, if remember it > correctly. Which is your model number? > > Ignacio EB4APL > > > El 04/11/2016 a las 16:35, Peter Reilley escribió: >> I gave up on trying to use the GPS 1 PPS signal to calibrate the 10 >> MHz OCXO's that >> I have. The reason that others have pointed out is that the >> uncorrected 1 PPS >> signal from the GPS is has just a little too much a jitter to use it >> for calibration >> with your eye using a scope. If it were sawtooth corrected then it >> would be better >> but you really need a GPS disciplined oscillator. >> >> Not to be outdone, I brought out a rubidium oscillator that I had put >> away because >> it did not appear to work properly. It only put out a 1 PPS signal >> and nothing else. >> I compared that with the GPS PPS and could get a good comparison on >> the scope. >> The rubidium drifted about 40 nS over 12 hours. So it seemed to be >> good. >> >> With that I could adjust the OCXO's in my 5370's. The spec for the >> HP 5370B with >> a HP 10811 OCXO is better than 1 X 10^-10 RMS for 1 sec average. That >> is, it should >> take more than 1,000 seconds for one 10 MHz wave to shift by 360 >> degrees. That >> is very hard to do using the screw adjustment in the OCXO. Even the >> slightest >> movement possible will cause a frequency change greater that is >> spec'ed. How >> do cal labs do it? >> >> My HP 5370A has a 10544 OCXO which is spec'ed for short term >> stability of >> better than 1 X 10^11 for 1 second. Even better than the 5370B! The >> adjustment >> screw is much coarser and it is not possible to get any better than a >> few seconds for >> one cycle phase shift of the 10 MHz OCXO against the standard. It >> seems that I can't >> get even close to the spec. >> >> These have been running for a few days. It that enough? >> >> Pete. > > > --- > El software de antivirus Avast ha analizado este correo electrónico en > busca de virus. > https://www.avast.com/antivirus > >

Satellite TV (Dish, Direct, etc) has been having trouble for 10 hours or so, sometimes losing some channels and occasionally all of them. Fox News is consistently down, so it could have a human cause, but Space Weather says we have unusual solar activity. I no longer have GPS time receivers, so I wonder how GPS is doing. Thanks for any comments. Bill Hawkins _______________________________________________ Bill, GPS is fine here in Edinburgh: http://www.satsignal.eu/mrtg/performance_gps.php Cheers, David -- SatSignal Software - Quality software written to your requirements Web: http://www.satsignal.eu Email: david-taylor@blueyonder.co.uk Twitter: @gm8arv

Hi A ten or twenty turn pot on a normal EFC will get you past the point that you can reasonably set the oscillator. The typical (not GPS version) EFC is down around 1 to 2 x 10^-7. A 20 turn pot will be running 1x10^-8 per turn. 100 to 200 points per turn is a pretty typical “set” number for a pot. That gets you into the sub 1x10^-10 region. The OCXO’s we are talking about have a temperature, pressure and humidity coefficient that each are well above that level. Bob > On Nov 4, 2016, at 2:31 PM, Scott Stobbe <scott.j.stobbe@gmail.com> wrote: > > I'm not sure if there is a reason counters don't let you digitally > calibrate beyond that, the 10 MHz ref out on the rear panel would still be > out of cal. > > On Fri, Nov 4, 2016 at 1:48 PM, Bob Camp <kb8tq@n1k.org> wrote: > >> Hi >> >> The only practical way to set the 10811 or 10544 is with a >= 10 turn pot >> on the EFC. I >> never have worked out just why there are so many instruments that don’t >> have a pot on >> the EFC. >> >> Bob >> >>> On Nov 4, 2016, at 11:35 AM, Peter Reilley <preilley_454@comcast.net> >> wrote: >>> >>> I gave up on trying to use the GPS 1 PPS signal to calibrate the 10 MHz >> OCXO's that >>> I have. The reason that others have pointed out is that the >> uncorrected 1 PPS >>> signal from the GPS is has just a little too much a jitter to use it for >> calibration >>> with your eye using a scope. If it were sawtooth corrected then it >> would be better >>> but you really need a GPS disciplined oscillator. >>> >>> Not to be outdone, I brought out a rubidium oscillator that I had put >> away because >>> it did not appear to work properly. It only put out a 1 PPS signal and >> nothing else. >>> I compared that with the GPS PPS and could get a good comparison on the >> scope. >>> The rubidium drifted about 40 nS over 12 hours. So it seemed to be >> good. >>> >>> With that I could adjust the OCXO's in my 5370's. The spec for the HP >> 5370B with >>> a HP 10811 OCXO is better than 1 X 10^-10 RMS for 1 sec average. That >> is, it should >>> take more than 1,000 seconds for one 10 MHz wave to shift by 360 >> degrees. That >>> is very hard to do using the screw adjustment in the OCXO. Even the >> slightest >>> movement possible will cause a frequency change greater that is >> spec'ed. How >>> do cal labs do it? >>> >>> My HP 5370A has a 10544 OCXO which is spec'ed for short term stability of >>> better than 1 X 10^11 for 1 second. Even better than the 5370B! The >> adjustment >>> screw is much coarser and it is not possible to get any better than a >> few seconds for >>> one cycle phase shift of the 10 MHz OCXO against the standard. It >> seems that I can't >>> get even close to the spec. >>> >>> These have been running for a few days. It that enough? >>> >>> Pete. >>> >>> >>> >>> On 11/3/2016 8:20 AM, Peter Reilley wrote: >>>> I am the proverbial man with too many clocks and I don't know what time >> it is. >>>> To correct this situation I have decided to calibrate everything. >>>> >>>> I have a HP 5370B, a HP 6370A, and a HP 5328A all with the TCXO >> option. I also >>>> have some TCXO modules. I figured that I would calibrate them against >> my Trimble >>>> Resolution T GPS receiver. >>>> >>>> I put the 1 PPS signal in one channel of my scope and one of the 10 MHz >> TCXO >>>> signals in the other channel and look at the phase relationship. The >> TCXO's are >>>> already close enough that I should not be out by more than a fraction >> of a waveform. >>>> I understand that I have to deal with the 1 PPS without sawtooth >> correction. >>>> >>>> I expected to see the 10 MHz signal bounce around but not move more >> than 1/2 >>>> of a wave length. Instead I see the 10 MHz waveform appear steady for >> a few seconds >>>> then jump a significant portion of the wave. The jump is too much to >> be confident >>>> that I have not slipped one cycle. >>>> >>>> Can I do what I am trying to do or am I missing something? >>>> >>>> Pete. >>>> >>>> _______________________________________________ >>>> time-nuts mailing 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.

I agree that FE-5680 is a whole family of products with very different features and these can not deducted from the labels. In my case I own a FE-5680A which outputs 1 PPS and a fixed (but slightly tunable) 10 MHz and needs 2 power supply voltages, +5 V and + 15 V. I am sending directly to you the information of the breakout board that I use and it includes the pinout of this unit. A caution here, some of the FE-5680 variations have different pinouts. Regards, Ignacio EB4APL El 05/11/2016 a las 2:01, Peter Reilley escribió: > It is a FE-5680B. It is my understanding that these were made in > many variations > of features but that what features were present or absent could not be > known > from the model numbers of other external identifying information. This > one > has the 1 PPS apparently. > > Pete. > > > > On 11/4/2016 1:07 PM, EB4APL wrote: >> A bit OT, but regarding your Rb, some units needs to be powered thru >> 2 pins, one is used only for the 10 MHz output buffer, if remember it >> correctly. Which is your model number? >> >> Ignacio EB4APL >> >> >> El 04/11/2016 a las 16:35, Peter Reilley escribió: >>> I gave up on trying to use the GPS 1 PPS signal to calibrate the 10 >>> MHz OCXO's that >>> I have. The reason that others have pointed out is that the >>> uncorrected 1 PPS >>> signal from the GPS is has just a little too much a jitter to use it >>> for calibration >>> with your eye using a scope. If it were sawtooth corrected then it >>> would be better >>> but you really need a GPS disciplined oscillator. >>> >>> Not to be outdone, I brought out a rubidium oscillator that I had >>> put away because >>> it did not appear to work properly. It only put out a 1 PPS signal >>> and nothing else. >>> I compared that with the GPS PPS and could get a good comparison on >>> the scope. >>> The rubidium drifted about 40 nS over 12 hours. So it seemed to be >>> good. >>> >>> With that I could adjust the OCXO's in my 5370's. The spec for the >>> HP 5370B with >>> a HP 10811 OCXO is better than 1 X 10^-10 RMS for 1 sec average. >>> That is, it should >>> take more than 1,000 seconds for one 10 MHz wave to shift by 360 >>> degrees. That >>> is very hard to do using the screw adjustment in the OCXO. Even the >>> slightest >>> movement possible will cause a frequency change greater that is >>> spec'ed. How >>> do cal labs do it? >>> >>> My HP 5370A has a 10544 OCXO which is spec'ed for short term >>> stability of >>> better than 1 X 10^11 for 1 second. Even better than the 5370B! >>> The adjustment >>> screw is much coarser and it is not possible to get any better than >>> a few seconds for >>> one cycle phase shift of the 10 MHz OCXO against the standard. It >>> seems that I can't >>> get even close to the spec. >>> >>> These have been running for a few days. It that enough? >>> >>> Pete. >> >> >> --- >> El software de antivirus Avast ha analizado este correo electrónico >> en busca de virus. >> https://www.avast.com/antivirus >> >> > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > --- El software de antivirus Avast ha analizado este correo electrónico en busca de virus. https://www.avast.com/antivirus