Re: [time-nuts] Different Survey Results
Peter, My TB is running continuously during months. It draws about 7 W using the black PWR-supply proposed by Tom (TvB). In the room at about 22 °C it does show 32.43 °C, I never passed 37 °C. So I would propose to net go beyond the 40 °C internal temp. reading. I will manufacture a wooden box with thick walls to stabilize the temp. Wood does of course not shield, but because the high thermal capacitance together with its isolation (moderate)it should result in a long thermal constant. Of course the temperature will come up, hopefully not surpassing 42 °C. Low temperature = longer lifetime. Your osc. Adev values are similar to mine, that should be ok (good). I can confirm the experience by Warren. I use 490 s,0.68 damp factor and a gain of -3.55 Hz/V actually resulting to PPS ADEV @ 1 tau 5.096E-11, @ 100 tau 3.05E-11, @ 500 tau 6.43E-12 @ 1000 tau 2.92E-12 Osc. ADEV @ 1 tau 3.39E-09, @ 100 tau 3.45E-11, @ 500 tau 7.05E-12 @ 1000 tau 3.32E-12 read by Lady Heather, which does not mean that these values are exact! This with the original OCXO, perhaps with an external oscillator one could get better results, but I had no luck yet. The PPS does very seldom exceed +- 5 ns, normally it does move just around +- 2 to 3 ns. The DAC-Voltage changes are in the range of +- 3 steps of around 25µV (a step presesents close to 8 µV) These are my observations, I hope it does help you. regards, Arnold Am 19.08.2010 23:59, schrieb Peter Krengel: To John WA4WDL: The coordinates out of my current (fixed) position calculated by the SirF GPS and the tbold during a 48h survey are different. On a map this differences makes up a shift of up to 100m around my true qth. With other words if I would (and could) use the tbold as a mobile GPS I would come off road at once ;) To ws: Thanks for the interesting answer and tips for modifying factory settings. My tbold works in a good stable (temperature) environment. I tried out to put it in a temp-isolated box but Osc temperature went up to about 50°C (not too hot?). Secondly I tried it without a box at normal 20°C room temperature (varying a little bit) and it showed OSC 41.75°C. What is the better choice? It also got fine antenna conditions (mostly 8 sats are recognized having signals between 38 and 48dBc) by using a roof top ceramic chip antenna (it has a inner preamp) followed by a 20dB wideband amp and about 20m coax. As I am located on a hill top it sees a 360° free sky down to 0° elevation. I got the following results using factory settings after cold start and 10 hours running with my true (are they really my true coords?) qth coordinates saved after self-survey: OSC ADEV 1tau 2.7E-09 1 tau 7.0E-13 My intension (of cause..) is to get the best out of the tbold in short and long term stability. The tbold isnt modified in any way running the original oscillator. What do you think ? To Mark: I too got a LPRO rubidium but it I'm not very satisfied because of the need of long time warm up after power fail and the need of a heat sink. In addition the tube wont last for ever and is used for 10(?) years... Anyway I would like to compare both tbold and Lpro if the tbold is setup best as possible. Thanks and regards Peter DG4EK ___ ___ time-nuts mailing 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] Different Survey Results
Hi The TBolt is rated to 70 C. You probably are ok running them at 50 C. The OCXO does not mind the heat and there's nothing else in there that has any noticeable heat rise. If you text search for pool of mercury in the archives you will hit a thread that goes into the details (and impracticality) of very long thermal time constants. The wood box with foam is a good way to go. Past that active control makes sense. Bob On Aug 20, 2010, at 3:23 AM, Arnold Tibus arnold.ti...@gmx.de wrote: Peter, My TB is running continuously during months. It draws about 7 W using the black PWR-supply proposed by Tom (TvB). In the room at about 22 °C it does show 32.43 °C, I never passed 37 °C. So I would propose to net go beyond the 40 °C internal temp. reading. I will manufacture a wooden box with thick walls to stabilize the temp. Wood does of course not shield, but because the high thermal capacitance together with its isolation (moderate)it should result in a long thermal constant. Of course the temperature will come up, hopefully not surpassing 42 °C. Low temperature = longer lifetime. Your osc. Adev values are similar to mine, that should be ok (good). I can confirm the experience by Warren. I use 490 s,0.68 damp factor and a gain of -3.55 Hz/V actually resulting to PPS ADEV @ 1 tau 5.096E-11, @ 100 tau 3.05E-11, @ 500 tau 6.43E-12 @ 1000 tau 2.92E-12 Osc. ADEV @ 1 tau 3.39E-09, @ 100 tau 3.45E-11, @ 500 tau 7.05E-12 @ 1000 tau 3.32E-12 read by Lady Heather, which does not mean that these values are exact! This with the original OCXO, perhaps with an external oscillator one could get better results, but I had no luck yet. The PPS does very seldom exceed +- 5 ns, normally it does move just around +- 2 to 3 ns. The DAC-Voltage changes are in the range of +- 3 steps of around 25µV (a step presesents close to 8 µV) These are my observations, I hope it does help you. regards, Arnold Am 19.08.2010 23:59, schrieb Peter Krengel: To John WA4WDL: The coordinates out of my current (fixed) position calculated by the SirF GPS and the tbold during a 48h survey are different. On a map this differences makes up a shift of up to 100m around my true qth. With other words if I would (and could) use the tbold as a mobile GPS I would come off road at once ;) To ws: Thanks for the interesting answer and tips for modifying factory settings. My tbold works in a good stable (temperature) environment. I tried out to put it in a temp-isolated box but Osc temperature went up to about 50°C (not too hot?). Secondly I tried it without a box at normal 20°C room temperature (varying a little bit) and it showed OSC 41.75°C. What is the better choice? It also got fine antenna conditions (mostly 8 sats are recognized having signals between 38 and 48dBc) by using a roof top ceramic chip antenna (it has a inner preamp) followed by a 20dB wideband amp and about 20m coax. As I am located on a hill top it sees a 360° free sky down to 0° elevation. I got the following results using factory settings after cold start and 10 hours running with my true (are they really my true coords?) qth coordinates saved after self-survey: OSC ADEV 1tau 2.7E-09 1 tau 7.0E-13 My intension (of cause..) is to get the best out of the tbold in short and long term stability. The tbold isnt modified in any way running the original oscillator. What do you think ? To Mark: I too got a LPRO rubidium but it I'm not very satisfied because of the need of long time warm up after power fail and the need of a heat sink. In addition the tube wont last for ever and is used for 10(?) years... Anyway I would like to compare both tbold and Lpro if the tbold is setup best as possible. Thanks and regards Peter DG4EK ___ ___ time-nuts mailing 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] Different Survey Results
Hello, I'm new to the list and to the themes at all. I'm running a V3 Thunderbolt using the great Lady Heather Software (thanks for this). Setting up the tbold for the first time I made a 48h survey. To compare the results I also started a SirF III GPS using VisualGPS software and after the 48h period I got totally different results. Knowing my real geografic coordinates very well I saw that the tbold obviously calculated wrong data. So my questions to the group are: 1. For getting best disciplining results out of the tbold: Do I better put in the coordinates manualy or using the survey function? 2. Is it necessary to modify DAC and temperature settings using command line options (or using the heather) or does tbold work best with factory settings? 3. Is there any How to.. pdf or book on the net which comes with more informations about the tbold experiences than the well known official pdf from 2003 ? Thank you very much for help. 73 from germany Peter Krengel DG4EK ___ time-nuts mailing 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] Different Survey Results
What do you mean by totally different results? What were the readings or the differences? John WA4WDL -- From: Peter Krengel krengelda...@gmx.de Sent: Thursday, August 19, 2010 12:28 PM To: time-nuts@febo.com Subject: [time-nuts] Different Survey Results Hello, I'm new to the list and to the themes at all. I'm running a V3 Thunderbolt using the great Lady Heather Software (thanks for this). Setting up the tbold for the first time I made a 48h survey. To compare the results I also started a SirF III GPS using VisualGPS software and after the 48h period I got totally different results. Knowing my real geografic coordinates very well I saw that the tbold obviously calculated wrong data. So my questions to the group are: 1. For getting best disciplining results out of the tbold: Do I better put in the coordinates manualy or using the survey function? 2. Is it necessary to modify DAC and temperature settings using command line options (or using the heather) or does tbold work best with factory settings? 3. Is there any How to.. pdf or book on the net which comes with more informations about the tbold experiences than the well known official pdf from 2003 ? Thank you very much for help. 73 from germany Peter Krengel DG4EK ___ time-nuts mailing 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] Different Survey Results
Peter asked: 2) Is it necessary to modify Tbolt settings or does tbold work best with factory settings? The answer is, for best performance you need to modify the factory setting. There has been much posted on which ones and how, but bottom line is it all depend on what your setup is and what you want it to do. It is a tradeoff to reduce the GPS short term noise and correct for the oscillator's long term noise. The best settings depend on what the noise frequencies and amplitude are in the two items and that depends on many things. The default setting for the Tbolt are meant to be used with a very GOOD antenna system and a not so good OCXO in a POOR environment. My situation is just the reverse. In one of my Tbolt units I'm using a very good OSC in a controlled constant temperature environment with a poor indoor antenna. The Default setting in this case are a disaster from a best performance standpoint. What I have found to give good general results if you do not want to fine tune your specific Tbolt unit and assuming a typical nut setup in a good environment (which includes adding some thermo mass to the Tbolt), 1) change the TC to 300, 2) the damping to 0.7 3) the Dac gain to -3.0 Hz/V, 4) the Elevation to 20 deg, 5) the AMU to 3.0 6) and then do a 24 or 48 hr survey if you are using Lady Heather or change the default survey size from 2,000 samples to more like 20,000+ samples, to a value that averages over at least 12 hrs, and have it save the location. ws *** [time-nuts] Different Survey Results Peter Krengel krengeldatec at gmx.de Thu Aug 19 16:28:52 UTC 2010 Hello, I'm new to the list and to the themes at all. I'm running a V3 Thunderbolt using the great Lady Heather Software (thanks for this). Setting up the tbold for the first time I made a 48h survey. To compare the results I also started a SirF III GPS using VisualGPS software and after the 48h period I got totally different results. Knowing my real geografic coordinates very well I saw that the tbold obviously calculated wrong data. So my questions to the group are: 1. For getting best disciplining results out of the tbold: Do I better put in the coordinates manualy or using the survey function? 2. Is it necessary to modify DAC and temperature settings using command line options (or using the heather) or does tbold work best with factory settings? 3. Is there any How to.. pdf or book on the net which comes with more informations about the tbold experiences than the well known official pdf from 2003 ? Thank you very much for help. 73 from germany Peter Krengel DG4EK ___ time-nuts mailing 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] Different Survey Results
Hi A few other things to try / consider: 1) Hit the auto calibrate function in LH to calibrate the slope of the OCXO, it will also load some damping and time constant stuff that you may want to overwrite. I don't know if this is a beta only feature or not. 2) Make sure that the TBolt isn't getting hit with drafts. Something as simple as a shoe box over it can help things quite a bit. 3) The +12 supply is fairly critical. Good regulation and low noise help stability 4) Clear view of the sky to the south (northern hemisphere) or north (southern hemisphere) helps the antenna a lot. Higher is usually better for GPS antennas. 5) The OCXO will run quite a bit better after it's been on for a while. How long depends on the one you have and how long it's been off. A few days to a few weeks may be involved. 6) Monitoring what's going on with long term charts on LH is very useful to diagnose specific issues. Lots of things to play with. None of it likely to cost much, other than some of your time. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Peter Krengel Sent: Thursday, August 19, 2010 12:29 PM To: time-nuts@febo.com Subject: [time-nuts] Different Survey Results Hello, I'm new to the list and to the themes at all. I'm running a V3 Thunderbolt using the great Lady Heather Software (thanks for this). Setting up the tbold for the first time I made a 48h survey. To compare the results I also started a SirF III GPS using VisualGPS software and after the 48h period I got totally different results. Knowing my real geografic coordinates very well I saw that the tbold obviously calculated wrong data. So my questions to the group are: 1. For getting best disciplining results out of the tbold: Do I better put in the coordinates manualy or using the survey function? 2. Is it necessary to modify DAC and temperature settings using command line options (or using the heather) or does tbold work best with factory settings? 3. Is there any How to.. pdf or book on the net which comes with more informations about the tbold experiences than the well known official pdf from 2003 ? Thank you very much for help. 73 from germany Peter Krengel DG4EK ___ time-nuts mailing 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] Different Survey Results
To John WA4WDL: The coordinates out of my current (fixed) position calculated by the SirF GPS and the tbold during a 48h survey are different. On a map this differences makes up a shift of up to 100m around my true qth. With other words if I would (and could) use the tbold as a mobile GPS I would come off road at once ;) To ws: Thanks for the interesting answer and tips for modifying factory settings. My tbold works in a good stable (temperature) environment. I tried out to put it in a temp-isolated box but Osc temperature went up to about 50°C (not too hot?). Secondly I tried it without a box at normal 20°C room temperature (varying a little bit) and it showed OSC 41.75°C. What is the better choice? It also got fine antenna conditions (mostly 8 sats are recognized having signals between 38 and 48dBc) by using a roof top ceramic chip antenna (it has a inner preamp) followed by a 20dB wideband amp and about 20m coax. As I am located on a hill top it sees a 360° free sky down to 0° elevation. I got the following results using factory settings after cold start and 10 hours running with my true (are they really my true coords?) qth coordinates saved after self-survey: OSC ADEV 1tau 2.7E-09 1 tau 7.0E-13 My intension (of cause..) is to get the best out of the tbold in short and long term stability. The tbold isnt modified in any way running the original oscillator. What do you think ? To Mark: I too got a LPRO rubidium but it I'm not very satisfied because of the need of long time warm up after power fail and the need of a heat sink. In addition the tube wont last for ever and is used for 10(?) years... Anyway I would like to compare both tbold and Lpro if the tbold is setup best as possible. Thanks and regards Peter DG4EK ___ time-nuts mailing 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] Different Survey Results
Hi Peter, Are you sure your known truth coordinates are in WGS84 datum? -- Björn To John WA4WDL: The coordinates out of my current (fixed) position calculated by the SirF GPS and the tbold during a 48h survey are different. On a map this differences makes up a shift of up to 100m around my true qth. With other words if I would (and could) use the tbold as a mobile GPS I would come off road at once ;) ___ time-nuts mailing 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] Different Survey Results
Hi To get to auto calibrate hit a and then it's the A option (Autotune rather than auto calibrate). Sorry for the confusion. Bob -- From: Bob Camp li...@rtty.us Sent: Thursday, August 19, 2010 5:10 PM To: 'Discussion of precise time and frequency measurement' time-nuts@febo.com Subject: Re: [time-nuts] Different Survey Results Hi A few other things to try / consider: 1) Hit the auto calibrate function in LH to calibrate the slope of the OCXO, it will also load some damping and time constant stuff that you may want to overwrite. I don't know if this is a beta only feature or not. 2) Make sure that the TBolt isn't getting hit with drafts. Something as simple as a shoe box over it can help things quite a bit. 3) The +12 supply is fairly critical. Good regulation and low noise help stability 4) Clear view of the sky to the south (northern hemisphere) or north (southern hemisphere) helps the antenna a lot. Higher is usually better for GPS antennas. 5) The OCXO will run quite a bit better after it's been on for a while. How long depends on the one you have and how long it's been off. A few days to a few weeks may be involved. 6) Monitoring what's going on with long term charts on LH is very useful to diagnose specific issues. Lots of things to play with. None of it likely to cost much, other than some of your time. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Peter Krengel Sent: Thursday, August 19, 2010 12:29 PM To: time-nuts@febo.com Subject: [time-nuts] Different Survey Results Hello, I'm new to the list and to the themes at all. I'm running a V3 Thunderbolt using the great Lady Heather Software (thanks for this). Setting up the tbold for the first time I made a 48h survey. To compare the results I also started a SirF III GPS using VisualGPS software and after the 48h period I got totally different results. Knowing my real geografic coordinates very well I saw that the tbold obviously calculated wrong data. So my questions to the group are: 1. For getting best disciplining results out of the tbold: Do I better put in the coordinates manualy or using the survey function? 2. Is it necessary to modify DAC and temperature settings using command line options (or using the heather) or does tbold work best with factory settings? 3. Is there any How to.. pdf or book on the net which comes with more informations about the tbold experiences than the well known official pdf from 2003 ? Thank you very much for help. 73 from germany Peter Krengel DG4EK ___ time-nuts mailing 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.
