Re: [time-nuts] oscillators
Chris, That is a big no ! What the Thunderbolt is doing is adjusting the OCXO to keep it aligned with a known reference from the GPS system. The fact that a microprocessor is involved is from a totally different perspective. A microprocessor controlled XO is a non oven crystal oscillator system that has additional computational control providing a bit more than just mere passive temperature compensation. The additional computational capability deals with having coefficients of that particular oscillator's behavior pre coded to compensate for the nonlinear behavior over a given temperature range. A microprocessor controlled XO system allows for using cheap crystals with minimum processing time and costs. Because of limited storage space there is no way for the system to have enough data to even try to compete with the quality of a decent OCXO. Beyond its initial calibration setup, it has no way of keeping it tied to a known reference, like the Thunderbolt is doing. BillWB6BNQ Chris Albertson wrote: On Mon, Aug 27, 2012 at 7:33 PM, Jim Lux jim...@earthlink.net wrote: On 8/27/12 4:15 PM, Rick Karlquist wrote: Several decades ago, the concept of the smart clock arose at what was then HP. The idea was as discussed here to characterize past aging, predict future aging, and then correct the aging. We know what a OCXO is and a TCXO is. I was at a presentation at work a whike back and they called what you describe a MPCXO or MicroProcessor Compensated XO.They said the characteristics were between the OCXO and TCXO Doesn't the thunderbolt do this. I think it watches the aging rate of the OCXO and adjusts during hold over. -- 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. ___ time-nuts mailing 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] HP/Agilet counter 53131A (not 53151A) trigger problems
www.*axtal*.com/data/publ/*aging*_e.pdf On Tue, Aug 28, 2012 at 2:32 AM, Don Latham d...@montana.com wrote: Could you refresh me with the reference or email the paper? I'd like to give it a read. Don Azelio Boriani My starting point is the paper by Neubig on the real vs. predicted aging: experimenting with the model and try to cut it around the Morion or the Oscilloquartz OCXOs. On Tue, Aug 28, 2012 at 12:15 AM, Don Latham d...@montana.com wrote: There are ways of generating models, such as ARIMA, using past behavior and the models used to tweak filters and so on. The shifts would have to be accounted for as they occur, seems to me. Now the interesting possibility is that a shift does not alter the underlying model for a given crystal Has to be tested. Don Azelio Boriani So it can't be done... the possibility to discipline an OCXO taking the action from a suitable model should help in speeding up the adjustments and avoiding the humps as seen in the Allan deviation plot. On Mon, Aug 27, 2012 at 9:31 PM, Don Latham d...@montana.com wrote: Isn't crystal aging marked by random jumps? perhaps lattice rearrangement? Really hard if not impossible to model... Don Azelio Boriani 30mV are -13dBm so maybe it is why the -20dBm is not a suitable level for that input. I have the 53132A and the 53181A so I can test (with the RS SML01). Is this problem new? Never tested before? About the OCXO aging: OK, I'm interested in the development of a model that can be general enough so that it can be steered, adjusting its parameters, during the OCXO life. The data (to adjust the parameters) will be gathered by the continuous monitoring with the GPS. On Mon, Aug 27, 2012 at 7:01 PM, Bernd Neubig bneu...@t-online.de wrote: Hi Azelio, Sorry, the counters are 53131A, not 53151A. The A and B inputs are specified from DC to 225 MHz with a sensitivity of y20 mV (rms) up to 100 MHz, 30 mV (rms) 100 ~ 200 MHz, and 50 mV (rms) 200 ~ 225 MHz. The problem can be at either input alone. The problem is only in the range between 100 MHz and 200 MHz, observed in automatic trigger mode. In manual trigger mode the counter does not trigger at all in that freq range. I cannot tell you an aging model for a particular OCXO, and I doubt if anyone can ;) Aging predictions can only be made on individual OCXO, unit by unit, and the prediction is only valid over a rather limited time. Therefore you must continuously monitor and update your prediction. Best regards Bernd DK1AG -Ursprüngliche Nachricht- Von: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] Im Auftrag von Azelio Boriani Gesendet: Freitag, 24. August 2012 17:28 An: Discussion of precise time and frequency measurement Betreff: Re: [time-nuts] HP/Agilet counter 53151A trigger problems From the datasheet: A input 10Hz..125MHz min level 25mVrms (-19dBm) B input min 50MHz, -20dBm the problem is on A input only? Maybe 150MHz for the A input, being beyond the official specifications, requires more signal on one counter than the other. In the past they all were fine? I have read your paper on the correlation between the real and predicted aging of crystal oscillators. I'm trying to find a suitable model for the Morion MV201 OCXO or the Oscilloquartz 8663 to implement a Kalman filter. On Fri, Aug 24, 2012 at 3:34 PM, Bernd Neubig bneu...@t-online.de wrote: Hi all, I have several HP/Agilent frequency counters 53151A (and 53152A) in my lab. Several of them meanwhile show trigger problems. I have tested the A and B channel between 5 MHz and 200 MHZ at three input levels of -10 dBm, 0 dBm and +10 dBm. Those with trigger problems show erroneous numbers at -10 dBm input level rather selectively, i.e. mostly at 100 MHz, some also at 150 MHz, while the are o.k. Has anyone on this list experienced similar defects and can give a recommendation how to fix/repair them? Best regards Bernd DK1AG www.axtal.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] Datum 1000B's any hints ?
If 5 V will not do it use a OPA 227 with a gain of 2. That is what I use as my test rig. Bert Kehren In a message dated 8/27/2012 10:54:02 P.M. Eastern Daylight Time, mspencer12...@yahoo.ca writes: Thanks.. That seems like a good next step. (Just to add to this, all three of the units have functional trim pots and two of three units will easily adjust to the correct frequency.) Message: 7 Date: Mon, 27 Aug 2012 22:24:06 -0400 (EDT) From: ewkeh...@aol.com To: time-nuts@febo.com Subject: Re: [time-nuts] Datum 1000B's any hints ? Message-ID: 1003d9.2a828d17.3d6d8...@aol.com Content-Type: text/plain; charset=US-ASCII without any EFC I would expect it to be 1 Hz low. If less than 5 Volt will get it on frequency I would use a 78L12 from your main supply followed by a TI REF02. Worked for me. Bert Kehren In a message dated 8/27/2012 10:13:35 P.M. Eastern Daylight Time, mspencer12...@yahoo.ca writes: Wondering if anyone has any practical suggestions as to the operation of stand alone Datum 1000B's.Over the last 6 months or so I've acquired 3 of them and I haven't been that impressed with their performance. I've got a nicely running FTS 1050 and an 8600 series bva along with time lab and some HP5370's so I'm reasonably confident in my references and test setup. I've been powering them from stand alone linear power supplies with separate supply and return leads for the oven and electronics and have left them alone for several weeks at a time. I haven't touched the efc input yet and am wondering if leaving that floating could be causing issues. I also tried running one of them from my stand alone 24 volt battery system which didn't seem to help. They all seem to be gradually getting better over time but I'm thinking either I have three duds or there is something basic I'm missing (ie. perhaps I need to connect the efc input ?). I'm also wondering what if anything to connect the case ground to. The most promising of the bunch from an adev perspective is also off frequency by approx a hz or so but seems to be slowly drifting towards the correct value. Any comments would be appreciated. Regards Mark Spencer. Sent from my iPad ___ ___ time-nuts mailing 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] oscillators
On 8/27/12 10:45 PM, Chris Albertson wrote: On Mon, Aug 27, 2012 at 7:33 PM, Jim Lux jim...@earthlink.net wrote: On 8/27/12 4:15 PM, Rick Karlquist wrote: Several decades ago, the concept of the smart clock arose at what was then HP. The idea was as discussed here to characterize past aging, predict future aging, and then correct the aging. We know what a OCXO is and a TCXO is. I was at a presentation at work a whike back and they called what you describe a MPCXO or MicroProcessor Compensated XO.They said the characteristics were between the OCXO and TCXO Doesn't the thunderbolt do this. I think it watches the aging rate of the OCXO and adjusts during hold over. Not really. The MCXO has a one time calibration for frequency vs temperature that's programmed into it (and some use *very* clever ways to measure the temperature). The disciplining algorithms in a GPSDO are a bit smarter; some explicitly develop a model for the f vs T and apply it, in others it's essentially embedded in a higher order filter which takes the measured T, along with other parameters, into the filter. I don't know if the GPSDOs try to do a time series fit/model (at least for low order terms) to deal with things like diurnal variation. They could. I should note that the MCXO approach, popularized as a better TCXO in a small low power package, is also used in some software defined radios, except that there's no separate microcontroller. The frequency vs temperature characteristic is just embedded in the other algorithms in the radio's host processor. ___ time-nuts mailing 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] Need usb time interval time for portable bullet chronograph
On 8/27/2012 6:15 PM, time-nuts-requ...@febo.com wrote: I got an old Meinberg GPS, with an analogue integrating single-channel receiver, and put at a friends appartment. Still works great, after me convincing it about a new location. It has two time-tagging inputs, so you can get UTC time-stamps with 100 ns resolution of the serial port. With a good trigger and then a serial adapter... you got some cool time-stamping good enough for the purpose I guess.:) Cheers, Magnus At 3000fps, even a one foot screen spacing would give good results with 100nS! On top of that you'd know the exact time of day, and location! We built some time measurement hardware at work with many channels running at 5nS resolution. Since a lot of us are into shooting sports, we did the math then. We basically figured figured that 5nS would be overkill for a chronograph. Fun, but overkill. :) 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] Lucent RTGm-II-XO Slow Acquisition
Hi Tom, Thanks for replying. I recently got a pair RFTGm-II-Rb and RFTGm-II-XO for an inexpensive price (less than a T-bolt). They appear late versions but I have not opened them up to get a version or date estimate. I came across the manual and software for these many years ago (~2005) from a website (now defunct) when I was searching for literature on an ATT RFG-RB standard I acquired for my ham radio workbench. I could not get the software to work with the ATT but it works great for the RFTGm's on Windows Vista with compatibility mode set for Win XP (SP2). Based on your feedback I thinkthe issue may be my Symmetricom antennae which I mounted for my T-bolt inside the peak of my attic (it was fast, easy and only some plywood and asphalt shingle between it and open sky :-). Yesterday we had some substantial overcast skies and maybe that plus my inside location (plus 70' of RG-8x) and the Lucent needing a bit more signal just was a bad combination. This morning under clear skies, I rebooted everything and within 30 minutes the RFTGm-II-Rb and RFTGm-II-XO were GPS-locked and working as a pair per the manual. I was pleasantly surprised reading the manual to find that in contrast to some messages on this reflector, the manual says that both the Rb and XO are each GPS disciplined by comparing the phase shift between their 1pps signals. The default is that the Rb is the primary standard while the XO is periodically used to verify and update further disciplining. Only issue for me then is the 10Mhz TP output from the RFTGm-II-Rb is a square wave not sine but I am searching for the best solution to convert this. If you have some suggestion - much appreciated ! Let me know if you want me to send you copies of the RFTG manual and Windows software. Jerry -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Tom Knox Sent: Tuesday, August 28, 2012 1:33 AM To: Time-Nuts Subject: Re: [time-nuts] Lucent RTGm-II-XO Slow Acquisition Hi Jerry ; I assume you mean RFTGm-II-XO. The cell sites usually had an Andrew 26dB antenna with a real short coax run. They also had a 40dB antenna option if needed. Unless you have a long coax run the Symmetricom ant should be ideal. I don't think the RFTGm-II-XO lock as quickly the Thundebolt but yours sounds like something is not right. Does the software allow you to set mask angle and PDOP? It could be set to high and be ignoring Sats. It also could possibly be set for a past fixed location. I have a few RFTGm-II-XO/RFTGm-II-RB combos but have never played with the software. Where did you find your software? And do you have a manual? Thanks; Thomas Knox From: jster...@att.net To: time-nuts@febo.com Date: Tue, 28 Aug 2012 00:28:27 -0400 Subject: [time-nuts] Lucent RTGm-II-XO Slow Acquisition I have a RTGm-II-XO and it takes quite some time to acquire the minimum 4 satellites. Using the same Symmetricom antenna with my Thunderbolt, it acquires 6-8 satellites in 15-20 mins while the RTGm-II-XO takes 60 minutes and sometimes much longer where I have power cycled it to get it out of warm-up. On power-up, the red alarm goes off within 15mins as programmed. I have preset my GPS coordinates using the RS-422 interface and Lucent software and set the coax length as well. The antenna voltage is correct at 4.9vdc and the antenna is drawing about 25 ma. The Lucent software shows correct XO voltages per the manual. Any advice appreciated. jerry ___ time-nuts mailing 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] oscillators
On Mon, Aug 27, 2012 at 11:45 PM, WB6BNQ wb6...@cox.net wrote: Chris, That is a big no ! What the Thunderbolt is doing is adjusting the OCXO to keep it aligned with a known reference from the GPS system. The fact that a microprocessor is involved is from a totally different perspective. Yes but but the t-bolt remembers the corrections is was applying and continues to apply them whenthe GPS signal goes away. I'm pretty sure one of the things it remembers is the aging rate. I know the real uP controlled XOs use programmed data for aging rate and temp compensation the t-bolt gts it's own data by comparing with GPS. 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] oscillators
On Tue, Aug 28, 2012 at 6:17 AM, Jim Lux jim...@earthlink.net wrote: The MCXO has a one time calibration for frequency vs temperature that's programmed into it (and some use *very* clever ways to measure the temperature). The disciplining algorithms in a GPSDO are a bit smarter; Yes, correct. But I was talking about during hold-over. t-bolt in holdover is no longer a GPSDO.It falls back on using a temperature and aging model. 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] HP/Agilet counter 53131A (not 53151A) trigger problems
thanks,Azelio. Neubig kindly sent the location for the references. Another good company, like the Wenzel site. Don Azelio Boriani www.*axtal*.com/data/publ/*aging*_e.pdf On Tue, Aug 28, 2012 at 2:32 AM, Don Latham d...@montana.com wrote: Could you refresh me with the reference or email the paper? I'd like to give it a read. Don Azelio Boriani My starting point is the paper by Neubig on the real vs. predicted aging: experimenting with the model and try to cut it around the Morion or the Oscilloquartz OCXOs. On Tue, Aug 28, 2012 at 12:15 AM, Don Latham d...@montana.com wrote: There are ways of generating models, such as ARIMA, using past behavior and the models used to tweak filters and so on. The shifts would have to be accounted for as they occur, seems to me. Now the interesting possibility is that a shift does not alter the underlying model for a given crystal Has to be tested. Don Azelio Boriani So it can't be done... the possibility to discipline an OCXO taking the action from a suitable model should help in speeding up the adjustments and avoiding the humps as seen in the Allan deviation plot. On Mon, Aug 27, 2012 at 9:31 PM, Don Latham d...@montana.com wrote: Isn't crystal aging marked by random jumps? perhaps lattice rearrangement? Really hard if not impossible to model... Don Azelio Boriani 30mV are -13dBm so maybe it is why the -20dBm is not a suitable level for that input. I have the 53132A and the 53181A so I can test (with the RS SML01). Is this problem new? Never tested before? About the OCXO aging: OK, I'm interested in the development of a model that can be general enough so that it can be steered, adjusting its parameters, during the OCXO life. The data (to adjust the parameters) will be gathered by the continuous monitoring with the GPS. On Mon, Aug 27, 2012 at 7:01 PM, Bernd Neubig bneu...@t-online.de wrote: Hi Azelio, Sorry, the counters are 53131A, not 53151A. The A and B inputs are specified from DC to 225 MHz with a sensitivity of y20 mV (rms) up to 100 MHz, 30 mV (rms) 100 ~ 200 MHz, and 50 mV (rms) 200 ~ 225 MHz. The problem can be at either input alone. The problem is only in the range between 100 MHz and 200 MHz, observed in automatic trigger mode. In manual trigger mode the counter does not trigger at all in that freq range. I cannot tell you an aging model for a particular OCXO, and I doubt if anyone can ;) Aging predictions can only be made on individual OCXO, unit by unit, and the prediction is only valid over a rather limited time. Therefore you must continuously monitor and update your prediction. Best regards Bernd DK1AG -Ursprüngliche Nachricht- Von: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] Im Auftrag von Azelio Boriani Gesendet: Freitag, 24. August 2012 17:28 An: Discussion of precise time and frequency measurement Betreff: Re: [time-nuts] HP/Agilet counter 53151A trigger problems From the datasheet: A input 10Hz..125MHz min level 25mVrms (-19dBm) B input min 50MHz, -20dBm the problem is on A input only? Maybe 150MHz for the A input, being beyond the official specifications, requires more signal on one counter than the other. In the past they all were fine? I have read your paper on the correlation between the real and predicted aging of crystal oscillators. I'm trying to find a suitable model for the Morion MV201 OCXO or the Oscilloquartz 8663 to implement a Kalman filter. On Fri, Aug 24, 2012 at 3:34 PM, Bernd Neubig bneu...@t-online.de wrote: Hi all, I have several HP/Agilent frequency counters 53151A (and 53152A) in my lab. Several of them meanwhile show trigger problems. I have tested the A and B channel between 5 MHz and 200 MHZ at three input levels of -10 dBm, 0 dBm and +10 dBm. Those with trigger problems show erroneous numbers at -10 dBm input level rather selectively, i.e. mostly at 100 MHz, some also at 150 MHz, while the are o.k. Has anyone on this list experienced similar defects and can give a recommendation how to fix/repair them? Best regards Bernd DK1AG www.axtal.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
Re: [time-nuts] Datum Lamp Voltage
Hi 6.0 to 7.0 volts is a *very* typical lamp voltage on an early LPRO. Later production runs did something that bumped the number up to around 9 volts. I've never seen any real data showing that the 9 volt parts are actually any better (or worse) than the 6.5 volt parts. The change could have just been a resistor value on a buffer amp... Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of J. Forster Sent: Monday, August 27, 2012 9:34 PM To: Discussion of precise time and frequency measurement Subject: [time-nuts] Datum Lamp Voltage Hi, I'm just powering a new to me Datum Rb, Type 102500-001, LPRO for the first time. The unit locks up quickly, and after about an hour, I checked the Lamp voltage. My unit is sitting at 6.9 VDC. From the manual on Didier's site, below 3.0 or over 14 indicate failure. Does anyone know whether the measured voltage should be for a new unit? I'm trying to guestimat the remaining life. Thanks, -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 mailing 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] oscillators
Hi I don't know that there is any data showing the TBolt adjusting for aging during holdover. In other words: showing the holdover DAC voltage changing at a completely constant temperature. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Chris Albertson Sent: Tuesday, August 28, 2012 12:19 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] oscillators On Tue, Aug 28, 2012 at 6:17 AM, Jim Lux jim...@earthlink.net wrote: The MCXO has a one time calibration for frequency vs temperature that's programmed into it (and some use *very* clever ways to measure the temperature). The disciplining algorithms in a GPSDO are a bit smarter; Yes, correct. But I was talking about during hold-over. t-bolt in holdover is no longer a GPSDO.It falls back on using a temperature and aging model. 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. ___ time-nuts mailing 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] oscillators
I don't know that there is any data showing the TBolt adjusting for aging during holdover. In other words: showing the holdover DAC voltage changing at a completely constant temperature. Bob I haven't seen any data either but here is information from section 5.1.2 of the 2003 Thunderbolt manual: Kalman filtering is a technique that improves the performance of a GPS disciplined clock when GPS drops out. This state is called holdover. During holdover the clock relies solely on the oscillator. Oscillator performance is subject to two basic effects. First, changes in environmental temperature can cause the oscillator to speed up [or] slow down. Second, the oscillator has a natural tendency to drift over time. This is called aging. Both temperature and aging can be mathematically predicted. However, the characteristics vary from crystal to crystal. The Kalman filtering monitors the unique oscillator performance over time and temperature and records this behavior. Then when the clock goes into holdover this filtering corrects for these effects producing a more accurate clock. The longer a clock has to ’train’ the better the Kalman filtering performance will be. 24 hours is considered the minimum necessary for good performance -Arthur ___ time-nuts mailing 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] oscillators
Hi ... then if you take a look at the status printout on a TBolt Kalman filter always shows up as disabled. Thus the who knows what they are doing. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Arthur Dent Sent: Tuesday, August 28, 2012 1:02 PM To: time-nuts@febo.com Subject: [time-nuts] oscillators I don't know that there is any data showing the TBolt adjusting for aging during holdover. In other words: showing the holdover DAC voltage changing at a completely constant temperature. Bob I haven't seen any data either but here is information from section 5.1.2 of the 2003 Thunderbolt manual: Kalman filtering is a technique that improves the performance of a GPS disciplined clock when GPS drops out. This state is called holdover. During holdover the clock relies solely on the oscillator. Oscillator performance is subject to two basic effects. First, changes in environmental temperature can cause the oscillator to speed up [or] slow down. Second, the oscillator has a natural tendency to drift over time. This is called aging. Both temperature and aging can be mathematically predicted. However, the characteristics vary from crystal to crystal. The Kalman filtering monitors the unique oscillator performance over time and temperature and records this behavior. Then when the clock goes into holdover this filtering corrects for these effects producing a more accurate clock. The longer a clock has to 'train' the better the Kalman filtering performance will be. 24 hours is considered the minimum necessary for good performance -Arthur ___ time-nuts mailing 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] HP/Agilet counter 53131A (not 53151A) trigger problems
The then Hughes Aircraft had a nice hybrid (microelectronic ) version of this idea produced in Newport Beach. --- On Mon, 8/27/12, Rick Karlquist rich...@karlquist.com wrote: From: Rick Karlquist rich...@karlquist.com Subject: Re: [time-nuts] HP/Agilet counter 53131A (not 53151A) trigger problems To: Discussion of precise time and frequency measurement time-nuts@febo.com Date: Monday, August 27, 2012, 4:15 PM Several decades ago, the concept of the smart clock arose at what was then HP. The idea was as discussed here to characterize past aging, predict future aging, and then correct the aging. The goal wasn't to turn a quartz oscillator into an atomic clock replacement, but simply to get the oscillator through a 1 hour or so holdover time during GPS outages. It sort of worked for that very limited purpose, but in general, past performance of HP crystals wasn't a very good predictor of future results. Crystals would age in one direction for a while and possibly slow down as time when on, but then then might start aging in the other direction. There were also frequency jumps that were substantial and totally random. The reason why the HP crystals were unpredictable was that all the deterministic processes such as mass preferentially depositing on the crystal, so as to make the frequency age lower, had been eliminated by years of manufacturing improvements. The remaining processes were of the nature of quartz stress relaxation that were very random. Rick Karlquist Don Latham wrote: There are ways of generating models, such as ARIMA, using past behavior and the models used to tweak filters and so on. The shifts would have to be accounted for as they occur, seems to me. Now the interesting possibility is that a shift does not alter the underlying model for a given crystal Has to be tested. Don Azelio Boriani So it can't be done... the possibility to discipline an OCXO taking the action from a suitable model should help in speeding up the adjustments and avoiding the humps as seen in the Allan deviation plot. On Mon, Aug 27, 2012 at 9:31 PM, Don Latham d...@montana.com wrote: Isn't crystal aging marked by random jumps? perhaps lattice rearrangement? Really hard if not impossible to model... Don Azelio Boriani 30mV are -13dBm so maybe it is why the -20dBm is not a suitable level for that input. I have the 53132A and the 53181A so I can test (with the RS SML01). Is this problem new? Never tested before? About the OCXO aging: OK, I'm interested in the development of a model that can be general enough so that it can be steered, adjusting its parameters, during the OCXO life. The data (to adjust the parameters) will be gathered by the continuous monitoring with the GPS. On Mon, Aug 27, 2012 at 7:01 PM, Bernd Neubig bneu...@t-online.de wrote: Hi Azelio, Sorry, the counters are 53131A, not 53151A. The A and B inputs are specified from DC to 225 MHz with a sensitivity of y20 mV (rms) up to 100 MHz, 30 mV (rms) 100 ~ 200 MHz, and 50 mV (rms) 200 ~ 225 MHz. The problem can be at either input alone. The problem is only in the range between 100 MHz and 200 MHz, observed in automatic trigger mode. In manual trigger mode the counter does not trigger at all in that freq range. I cannot tell you an aging model for a particular OCXO, and I doubt if anyone can ;) Aging predictions can only be made on individual OCXO, unit by unit, and the prediction is only valid over a rather limited time. Therefore you must continuously monitor and update your prediction. Best regards Bernd DK1AG -Ursprüngliche Nachricht- Von: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] Im Auftrag von Azelio Boriani Gesendet: Freitag, 24. August 2012 17:28 An: Discussion of precise time and frequency measurement Betreff: Re: [time-nuts] HP/Agilet counter 53151A trigger problems From the datasheet: A input 10Hz..125MHz min level 25mVrms (-19dBm) B input min 50MHz, -20dBm the problem is on A input only? Maybe 150MHz for the A input, being beyond the official specifications, requires more signal on one counter than the other. In the past they all were fine? I have read your paper on the correlation between the real and predicted aging of crystal oscillators. I'm trying to find a suitable model for the Morion MV201 OCXO or the Oscilloquartz 8663 to implement a Kalman filter. On Fri, Aug 24, 2012 at 3:34 PM, Bernd Neubig bneu...@t-online.de wrote: Hi all, I have several HP/Agilent frequency counters 53151A (and 53152A) in my lab. Several of them meanwhile show trigger problems. I have tested the A and B channel between 5 MHz and 200 MHZ at three input levels of -10 dBm, 0 dBm and +10 dBm. Those with trigger problems show erroneous numbers at -10 dBm input level rather selectively, i.e. mostly at 100 MHz, some also at
Re: [time-nuts] Datum Lamp Voltage
I can confirm what Bob wrote. From my log, these are the Lamp V of my 9 working LPROs: 8.25 5.18 7.74 6.54 6.5 7 6 6.5 7 The one that gives 5.18V seems to have some problem with the capacitive trimmer near the lamp. Antonio I8IOV Bob wrote: 6.0 to 7.0 volts is a *very* typical lamp voltage on an early LPRO. ___ time-nuts mailing 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] Datum Lamp Voltage
Antonio that cap peaks the rf. They get bad over time and cause an issue. You may find it to be noisy/touchy and if replaced you could get a higher rf voltage and a brighter lamp. Regards Paul WB8TSL On Tue, Aug 28, 2012 at 3:24 PM, iov...@inwind.it iov...@inwind.it wrote: I can confirm what Bob wrote. From my log, these are the Lamp V of my 9 working LPROs: 8.25 5.18 7.74 6.54 6.5 7 6 6.5 7 The one that gives 5.18V seems to have some problem with the capacitive trimmer near the lamp. Antonio I8IOV Bob wrote: 6.0 to 7.0 volts is a *very* typical lamp voltage on an early LPRO. ___ time-nuts mailing 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] Datum Lamp Voltage
From what I've seen, peaking the lamp voltage with the trimmer capacitor on an LPro does not improve the stability. It may even get a bit worse. This was the case on a couple of different units; I didn't investigate further. -- john, KE5FX www.miles.io -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts- boun...@febo.com] On Behalf Of Bob Camp Sent: Tuesday, August 28, 2012 9:35 AM To: j...@quikus.com; 'Discussion of precise time and frequency measurement' Subject: Re: [time-nuts] Datum Lamp Voltage Hi 6.0 to 7.0 volts is a *very* typical lamp voltage on an early LPRO. Later production runs did something that bumped the number up to around 9 volts. I've never seen any real data showing that the 9 volt parts are actually any better (or worse) than the 6.5 volt parts. The change could have just been a resistor value on a buffer amp... Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts- boun...@febo.com] On Behalf Of J. Forster Sent: Monday, August 27, 2012 9:34 PM To: Discussion of precise time and frequency measurement Subject: [time-nuts] Datum Lamp Voltage Hi, I'm just powering a new to me Datum Rb, Type 102500-001, LPRO for the first time. The unit locks up quickly, and after about an hour, I checked the Lamp voltage. My unit is sitting at 6.9 VDC. From the manual on Didier's site, below 3.0 or over 14 indicate failure. Does anyone know whether the measured voltage should be for a new unit? I'm trying to guestimat the remaining life. Thanks, -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 mailing 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] Shera PIC Firmware file
Hi guys, The hex file is quite outdated. In 2009 I contacted Brook Shera in order to get the source code as I wanted to build this controller and wanted to change the PIC to use a Flash one and add some improvements. His response was that he already had changed the microcontroler for a more modern unit, a PIC 16F876A, and included a lot of improvements. He also informed me that he was not releasing the hex or source code anymore but he could sell me programmed PICs with the last version and some other components like the AD1861 at least while his supply last. He also supplied me the critical 74HC4046's and even the 24 MHz xtal oscillator. I also ordered a board from AA Engineering and now I have to find the time to build it. So I recommend you contact with Mr Shera for the last versions of this software. His email has changed since the mentioned QST article and in 2009 was: ebs(AT)mailaps.org Best regards, Ignacio, EB4APL On 28/08/2012 7:30, WB6BNQ wrote: Hi Ron, My apologies, I got to typing and forgot to append the URL line; which is: http://www.rt66.com/~shera/index_fs.htm Sorry about that ! If you haven't already it is worth reading the original QST article which he has a link to at the bottom of the page. BillWB6BNQ Ron Ward wrote: Hi Bill: I don't see the address for Shera's web page! Thanks, Ron -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of WB6BNQ Sent: Monday, August 27, 2012 3:16 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Shera PIC Firmware file Ron, Here is Mr. Shera's actual web page on the topic. At the bottom you will find the HEX file file for the firmware. Don't ask as there is no published assembly listing of the firmware. Mr. Shera does not feel like releasing it to the general public at this time. Also, on that page is a link to the original article he wrote on the project. So it is a good page to bookmark. BillWB6BNQ Ron Ward wrote: Hi again all: Does anyone know where I can get a copy of Shera's PIC firmware for his GPS-Based Frequency Standard? Also, what enhancements are available for the latest firmware? Thanks again, Ron ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Shera PIC Firmware file
Sorry, I meant Brooks Shera. Regards, Ignacio, EB4APL On 28/08/2012 23:20, EB4APL wrote: Hi guys, The hex file is quite outdated. In 2009 I contacted Brook Shera in order to get the source code as I wanted to build this controller and wanted to change the PIC to use a Flash one and add some improvements. His response was that he already had changed the microcontroler for a more modern unit, a PIC 16F876A, and included a lot of improvements. He also informed me that he was not releasing the hex or source code anymore but he could sell me programmed PICs with the last version and some other components like the AD1861 at least while his supply last. He also supplied me the critical 74HC4046's and even the 24 MHz xtal oscillator. I also ordered a board from AA Engineering and now I have to find the time to build it. So I recommend you contact with Mr Shera for the last versions of this software. His email has changed since the mentioned QST article and in 2009 was: ebs(AT)mailaps.org Best regards, Ignacio, EB4APL ___ time-nuts mailing 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] (no subject)
The Kalman filter referred to in the status display refers to a Kalman filter on the position, not the one used to discipline the oscillator during holdover. The on;y device that I have seen that implements the Kalman position filter is one of the Resolution-T models (I don't remember if it was the -SMT or the older version). ... then if you take a look at the status printout on a TBolt Kalman filter always shows up as disabled. Thus the who knows what they are doing. ___ time-nuts mailing 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] Isotemp OCXO trimpot question...
Now I need to find a 10 KW potentiometer! John -- From: Jerry jster...@att.net Sent: Monday, August 27, 2012 8:10 PM To: 'Discussion of precise time and frequency measurement' time-nuts@febo.com Subject: Re: [time-nuts] Isotemp OCXO trimpot question... I don't know if the list allows attachments but I tried to attach to this email a datasheet for a very similar Isotemp 10Mhz OCXO (Model OCXO134-10; PN 6624.2). Just in case the attachment doesn't come thru here is the relevant section. I am not certain whether the pins are the same as your model but I believe all the Isotemp OCXO have same arrangement: 3. ELECTRICAL FREQUENCY ADJUSTMENT 3.1. Range ±0.45 PPM ±1.2 PPM (At time of shipment) (Referenced to nominal frequency) 3.2. Control 0 VDC to Vref (0 VDC to +8 VDC ) or a 10 kW potentiometer connected between pins 2 and 4 with wiper connected to pin 3. 3.3. Slope Positive 3.4. Center Vref/2 ±10% of Vref (+4 VDC to +0.8 VDC) Jerry -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Azelio Boriani Sent: Monday, August 27, 2012 6:57 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Isotemp OCXO trimpot question... If there is no datasheet to refer to then the usual value is between 10K and 20K. 10K is the most common value for 5V or 8V Vref. The OCXO should provide the Vref output pin to connect one side of the pot, the other to GND, for a GND referenced EFC. Your mileage may vary but, without a datasheet, it is the best starting point. On Mon, Aug 27, 2012 at 11:26 PM, Bud Patten bud.pat...@frontiernet.netwrote: I have an Isotemp OCXO (674-0010-000) an am wondering what is the recommended value for the frequency trim pot? Bud W0LCP Time is only there to prevent everything from happening at once. Einstein ___ time-nuts mailing 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] Isotemp OCXO trimpot question...
Read more carefully, Bob. It was a joke based on a typo. On 8/28/2012 5:44 PM, Bob Camp wrote: Hi I wouldn't go to crazy digging up a 10K pot. I suspect that anything in the 10K to 50K range will work ok. Bob On Aug 28, 2012, at 8:24 PM, jmfrankejmfra...@cox.net wrote: Now I need to find a 10 KW potentiometer! John -- From: Jerryjster...@att.net Sent: Monday, August 27, 2012 8:10 PM To: 'Discussion of precise time and frequency measurement'time-nuts@febo.com Subject: Re: [time-nuts] Isotemp OCXO trimpot question... I don't know if the list allows attachments but I tried to attach to this email a datasheet for a very similar Isotemp 10Mhz OCXO (Model OCXO134-10; PN 6624.2). Just in case the attachment doesn't come thru here is the relevant section. I am not certain whether the pins are the same as your model but I believe all the Isotemp OCXO have same arrangement: 3. ELECTRICAL FREQUENCY ADJUSTMENT 3.1. Range ±0.45 PPM ±1.2 PPM (At time of shipment) (Referenced to nominal frequency) 3.2. Control 0 VDC to Vref (0 VDC to +8 VDC ) or a 10 kW potentiometer connected between pins 2 and 4 with wiper connected to pin 3. 3.3. Slope Positive 3.4. Center Vref/2 ±10% of Vref (+4 VDC to +0.8 VDC) Jerry ___ time-nuts mailing 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] HP5065A Repairable?
Hi: I have been thinking about purchasing a HP5065A Rubidium Frequency Standard. Are all of the critical parts still available for them? What is a reasonable price for one? What usually goes wrong with them? Would I be better off to just purchase a SRS PRS-10? Any ideas and input would be greatly appreciated!!! Thanks, Ron ___ time-nuts mailing 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] HP5065A Repairable?
Ron I guess with some humor the critical part the RB gas is not. :-) The srd would be a killer also. But pretty much everything else is very reasonable and adaptable with modern technology. Only spares would be ebay parts or something like that. They have been out of production a long time. So that said. I really like the one I have. But given X dollars to spend, the higher the cost someone would want the more I would lean towards the other things that are available today. Regards Paul WB8TSL On Tue, Aug 28, 2012 at 10:57 PM, Ron Ward n6idl...@comcast.net wrote: Hi: I have been thinking about purchasing a HP5065A Rubidium Frequency Standard. Are all of the critical parts still available for them? What is a reasonable price for one? What usually goes wrong with them? Would I be better off to just purchase a SRS PRS-10? Any ideas and input would be greatly appreciated!!! Thanks, Ron ___ time-nuts mailing 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] HP5065A Repairable?
Dear Ron, Good morning. I just finished rebuilding a not so beaten 5065a. The physics package is ok. It is one of the later units. I had to spend several weeks working on power supplies, regulators and changing every single capacitor on the boards for security matters as no capacitor was showing the required specs. After that I replaced an IC commonly available, several transistors, cleaned inside-out and voila! It is working as good as new. Well I think I am exaggerating a little bit, but I still hold the hight spirits for it to perform like this for the years to come. Or should I say months? Knock on wood. Once repaired I went to the cosmetics, I got matched beige paint to cover some dings and small scratches. Cleaned everything with Windex and a toothbrush NOTE: WITHOUT THE PHYSICS PACKAGE MOUNTED INSIDE THE CASE. Rubidium and water don't get along and even if the physics package is completely sealed please do not take any chances. After that I used Scotch 3M dish cleaner sponge with the green abrasive felt to clean and renew the appearance of the aluminium trim. It looks like new. A little Dremel soft polishing wheel and all the screw heads are like new, also connectors to keep everything in original state. For the main control and adjustment area I used a jeweller silver cleaning cloth. It is very soft on delicate metallic surfaces and cleans/shines at the same time. In short I got a new looking unit. I payed less than $800 USD for it along with spare parts, cleaning material and a visit to my electronics guru who guided me through testing of the oscillator and checking everything to original specs in his lab. I love having the 5065a. It is just a fine toy which also gives pride of ownership. Best if it is performing like it should. I wish I could find another one. Better equipped. Mine is barebones without any option. I still have to get the Bendix looking DC power connector to use a decent DC battery backup. My model is also the one that could use the digital led clock on the right hand side of the instrument. I bought an HP 59309a digital clock to match it and finally see some integrated frequencies as time. If you need any other information I could possibly share, please feel free to contact me anytime. There is a lot of expertise in this fine group for HP rubidiums. I bet Corby Dawson could jump into the scene. He has been very kind to me offering his experience in 5065a repair and reconstruction. I better keep his contact information close to the night table in case nightmares visit me tonight. Cheers and please share your experiences whenever you are ready to take the plunge. Regards, Edgardo Molina Dirección IPTEL www.iptel.net.mx T : 55 55 55202444 M : 04455 20501854 Piensa en Bits SA de CV Información anexa: CONFIDENCIALIDAD DE INFORMACION Este mensaje tiene carácter confidencial. Si usted no es el destinarario de este mensaje, le suplicamos se lo notifique al remitente mediante un correo electrónico y que borre el presente mensaje y sus anexos de su computadora sin retener una copia de los mismos. Queda estrictamente prohibido copiar este mensaje o hacer usode el para cualquier propósito o divulgar su en forma parcial o total su contenido. Gracias. NON-DISCLOSURE OF INFORMATION This email is strictly confidential and may also be privileged. If you are not the intended recipient please immediately advise the sender by replying to this e-mail and then deleting the message and its attachments from your computer without keeping a copy. It is strictly forbidden to copy it or use it for any purpose or disclose its contents to any third party. Thank you. On Aug 28, 2012, at 9:57 PM, Ron Ward n6idl...@comcast.net wrote: Hi: I have been thinking about purchasing a HP5065A Rubidium Frequency Standard. Are all of the critical parts still available for them? What is a reasonable price for one? What usually goes wrong with them? Would I be better off to just purchase a SRS PRS-10? Any ideas and input would be greatly appreciated!!! Thanks, Ron ___ time-nuts mailing 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] PROM decode of FE-5680A
Hi, has anyone yet managed to extract and/or disassemble the eprom of an FE-5680A? Im willing to help with disassembly/decoding if you have the binary dump. Cheers. -- Mike McCauley mi...@open.com.au Open System Consultants Pty. Ltd 9 Bulbul Place Currumbin Waters QLD 4223 Australia http://www.open.com.au Phone +61 7 5598-7474 Fax +61 7 5598-7070 Radiator: the most portable, flexible and configurable RADIUS server anywhere. SQL, proxy, DBM, files, LDAP, NIS+, password, NT, Emerald, Platypus, Freeside, TACACS+, PAM, external, Active Directory, EAP, TLS, TTLS, PEAP, TNC, WiMAX, RSA, Vasco, Yubikey, MOTP, HOTP, TOTP, DIAMETER etc. Full source on Unix, Windows, MacOSX, Solaris, VMS, NetWare etc. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
