Re: [time-nuts] 53132A Polish UHS Time Base Option Interesting Ovservation
And this is where one question leads to another. For an oscillator that is going to be used at very high velocities and accelerations, like in a missile, would it be calibrated somehow under the target G force? Or would you just compensate some other way? Or just not worry about it? Dan On May 12, 2015, at 6:51 AM, Bob Camp kb...@n1k.org wrote: Hi All OCXO’s are sensitive to acceleration. Gravity is one form of acceleration. A sensitivity in the 0.5 to 2 ppb / G is not uncommon. Bob On May 11, 2015, at 9:24 PM, J. L. Trantham jlt...@att.net wrote: I recently obtained a 53132A and added the HP Opt 010 High Stability Time Base option with a 10811 variant OCXO. I left it on for over a week and it, ultimately, seemed to slow down in its drift, with the displayed frequency, as it 'read' my GPSDO, slowly decreasing, suggesting that the Time Base was, slowly, increasing in frequency. I then removed the HP option and installed a Polish UHS Time Base option with a Morion DOCXO. After about 72 hours, it seemed to stabilize. I then 'calibrated' the 53132A by connecting my GPSDO to Channel 1. The displayed frequency was +/- 1 to 2 mHz of 10.000 000 000 MHz for the past week or so, with no drift noticeable. I had 'calibrated' the 53132A with it sitting at about +30 degrees, propped up on its 'handle' in a 'vertical' position. I then had occasion to move the 'handle' under the unit whereby the unit was 'flat', at which point the displayed frequency dropped to 9.999 999 997 MHz, +/- 1 to 2 mHz. The displayed frequency was the same this evening when I came home. When I again 'elevated' the unit by moving the handle to its more 'vertical' position, the displayed frequency moved to 10.000 000 000 MHz +/- 1 to 2 mHz. I'm not sure what this means. It is a 'repeatable' observation. It displayed the lower frequency all day and when I 'elevated' the 53132A this evening, the frequency again went to 10.000 000 000 Mhz. Is this a 'gravity' effect? Is this an issue with the DOCXO? Is this an issue with the 53132A? If I am correct in my calculations, the displayed frequency is +/- 1 to 2 parts in 10E-10 of 10 MHz, assuming my GPSDO is accurate and stable. Otherwise, the GPSDO and 53132A 'drift' is exactly the same. I would appreciate anyone's thoughts regarding this analysis and observation and how to go about 'quantifying' it in a more scientific method, assuming it's worth pursuing. Thanks in advance. Joe ___ time-nuts mailing 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] 53132A Polish UHS Time Base Option Interesting Ovservation
On Tue, 12 May 2015 15:15:51 +1000 Tim t...@skybase.net wrote: For an explanation... http://www.eevblog.com/2014/07/31/eevblog-646-gravity-detection-using-a-frequency-counter/ regards For a real explanation, see Vig's Quartz Crystal Resonator/Oscillator Tutorial, which you can find, for example, on Didier's site[1]. Attila Kinali [1] http://ko4bb.com/manuals/index.php?dir=02_GPS_Timing/John_Vig_Tutorials_on_Crystal_Oscillators -- It is upon moral qualities that a society is ultimately founded. All the prosperity and technological sophistication in the world is of no use without that foundation. -- Miss Matheson, The Diamond Age, Neil Stephenson ___ time-nuts mailing 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] Small time server for mobile use.
What's your budget? I've done this with 1U sized NTP servers from Symmetricom (S300 and S350 systems) for mobile military use. These are a few thousand bucks a pop. They're rugged, and held up just fine in places the military goes.Compared to the rest of the system I was working on, this was quite small in comparison and we used more than one at each location. My personal one died recently so I'm working on developing a cape for the BeagleBone Black. The prototype is working just fine so far so I'm moving forward with a board layout and eventual sale to the list members if there is any interest (I'm not asking for interest yet). -Bob On Tue, May 12, 2015 at 11:11 AM, Mark Spencer m...@alignedsolutions.com wrote: Hi sorry for a possibly OT post. Has anyone had practical experience with small commercially available time servers / ntp servers suitable for mobile use in a vehicle. The use case is I am in need of an accurate (ie. within 100 ms) time source for several pc's in moving vehicle.Being able to run directly off a 13.8 or 28 VDC source would be a major plus but AC power is also available. Hold over if there are gaps in GPS coverage is also a major plus. We already have a GPS with a 1 pps output, but an integrated box with it's own GPS would be best. Yes I am aware I could feed a 1 pps signal into a laptop and use that as a time server and I may end up going that route. There is a small Ethernet LAN in the vehicle. The pc's currently get their time via a wireless connection to various NTP servers. I need to be able to ensure accurate time on the PC's if there is no wireless coverage. This is for a one off project so piecing together various parts is an option but a single box COTS solution would be nice. I've found a few candidates via web searches but would welcome any feed back. Thanks in advance Mark Spencer ___ time-nuts mailing 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] Small time server for mobile use.
Hi! You can try Laureline GPS NTP Server https://www.tindie.com/products/gxti/laureline-gps-ntp-server/. I have no personal experience with this box but it seems to satisfy all your requirements. Edésio On Tue, May 12, 2015 at 10:11:52AM -0700, Mark Spencer wrote: Hi sorry for a possibly OT post. Has anyone had practical experience with small commercially available time servers / ntp servers suitable for mobile use in a vehicle. The use case is I am in need of an accurate (ie. within 100 ms) time source for several pc's in moving vehicle.Being able to run directly off a 13.8 or 28 VDC source would be a major plus but AC power is also available. Hold over if there are gaps in GPS coverage is also a major plus. We already have a GPS with a 1 pps output, but an integrated box with it's own GPS would be best. Yes I am aware I could feed a 1 pps signal into a laptop and use that as a time server and I may end up going that route. There is a small Ethernet LAN in the vehicle. The pc's currently get their time via a wireless connection to various NTP servers. I need to be able to ensure accurate time on the PC's if there is no wireless coverage. This is for a one off project so piecing together various parts is an option but a single box COTS solution would be nice. I've found a few candidates via web searches but would welcome any feed back. Thanks in advance Mark Spencer ___ time-nuts mailing 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] Small time server for mobile use.
On Tue, May 12, 2015 at 7:11 PM, Mark Spencer m...@alignedsolutions.com wrote: Hi sorry for a possibly OT post. Has anyone had practical experience with small commercially available time servers / ntp servers suitable for mobile use in a vehicle. I don't know about any commercially-available products, but it sounds like it'd be pretty straightforward to do with a Raspberry Pi or something similar if you don't mind a little bit of DIY. What constraints do you have on budget, size, power requirements, and cooling? The use case is I am in need of an accurate (ie. within 100 ms) time source for several pc's in moving vehicle.Being able to run directly off a 13.8 or 28 VDC source would be a major plus but AC power is also available. The Pi runs on 5V DC. DC-DC buck converters that can convert 7-35V to 5V DC are cheap, efficient, and widely available. Shouldn't be a problem. Hold over if there are gaps in GPS coverage is also a major plus. How long would you need holdover? Seconds or minutes (e.g. driving through a tunnel)? Hours? Days? Would the computers in the vehicle be subject to large temperature shifts? A Pi should be able to handle +/- 100ms of holdover in the minutes-to-hours range using NTP. We already have a GPS with a 1 pps output, but an integrated box with it's own GPS would be best. A tiny integrated module like the Adafruit Ultimate GPS breakout[1] is cheap, handy, and emits a 1PPS signal. It's also extremely small and can be purchased in hat form[2] that mounts directly to the Pi. Cheers! -Pete [1] https://www.adafruit.com/products/746 [2] https://www.adafruit.com/products/2324 -- Pete Stephenson On Tue, May 12, 2015 at 7:11 PM, Mark Spencer m...@alignedsolutions.com wrote: Hi sorry for a possibly OT post. Has anyone had practical experience with small commercially available time servers / ntp servers suitable for mobile use in a vehicle. The use case is I am in need of an accurate (ie. within 100 ms) time source for several pc's in moving vehicle.Being able to run directly off a 13.8 or 28 VDC source would be a major plus but AC power is also available. Hold over if there are gaps in GPS coverage is also a major plus. We already have a GPS with a 1 pps output, but an integrated box with it's own GPS would be best. Yes I am aware I could feed a 1 pps signal into a laptop and use that as a time server and I may end up going that route. There is a small Ethernet LAN in the vehicle. The pc's currently get their time via a wireless connection to various NTP servers. I need to be able to ensure accurate time on the PC's if there is no wireless coverage. This is for a one off project so piecing together various parts is an option but a single box COTS solution would be nice. I've found a few candidates via web searches but would welcome any feed back. Thanks in advance Mark Spencer ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- Pete Stephenson ___ time-nuts mailing 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] Time in a cave
I'm looking for information on non-GPS time sources. For background, I need to provide PTP to a cluster where we don't have line of sight to the sky, and are unlikely to get roof-rights without a fight. There are CDMA solutions that would work (e.g. Endrun Technologies), but I was wondering if there were any other options. I either need an indoor capable PTP, or an indoor capable PPS. Microsemi claims to have an indoor capable GNSS system, but I've yet to find a sales rep to talk about it; if anyone has a link to one who can, I'd love to find out the problems^W^W^W^W talk to them about it. For an example of something that almost but doesn't quite work, Beagle Software has a CDMA NTP server, but they do neither PTP nor PPS in the CDMA version. Similarly, Meinberg will sell a PTP unit that freeruns (if you override the config), but they have no solution to discipline via CDMA. I'm also curious if anyone has any idea about non-GPS time sync after CDMA gets turned off (can I get time from 4G?). My endgame worst case is to just do PPS from a stratum 2 NTP (or even a freerunning oscillator) and lie to my PTP server; hard sync to UTC is a secondary concern so long as the cluster agrees with itself. Endrun is looking pretty good, but I'd really like to have a second option to compare against. -Joe ___ time-nuts mailing 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] Small time server for mobile use.
Hi sorry for a possibly OT post. Has anyone had practical experience with small commercially available time servers / ntp servers suitable for mobile use in a vehicle. The use case is I am in need of an accurate (ie. within 100 ms) time source for several pc's in moving vehicle.Being able to run directly off a 13.8 or 28 VDC source would be a major plus but AC power is also available. Hold over if there are gaps in GPS coverage is also a major plus. We already have a GPS with a 1 pps output, but an integrated box with it's own GPS would be best. Yes I am aware I could feed a 1 pps signal into a laptop and use that as a time server and I may end up going that route. There is a small Ethernet LAN in the vehicle. The pc's currently get their time via a wireless connection to various NTP servers. I need to be able to ensure accurate time on the PC's if there is no wireless coverage. This is for a one off project so piecing together various parts is an option but a single box COTS solution would be nice. I've found a few candidates via web searches but would welcome any feed back. Thanks in advance Mark Spencer ___ time-nuts mailing 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] 53132A Polish UHS Time Base Option Interesting Ovservation
Zyfer have(had?) some papers on g-compensated oscillators by Fruehof. -- Björn div Originalmeddelande /divdivFrån: D W watsondani...@gmail.com /divdivDatum:2015-05-12 17:49 (GMT+01:00) /divdivTill: Discussion of precise time and frequency measurement time-nuts@febo.com /divdivRubrik: Re: [time-nuts] 53132A Polish UHS Time Base Option Interesting Ovservation /divdiv /div And this is where one question leads to another. For an oscillator that is going to be used at very high velocities and accelerations, like in a missile, would it be calibrated somehow under the target G force? Or would you just compensate some other way? Or just not worry about it? Dan On May 12, 2015, at 6:51 AM, Bob Camp kb...@n1k.org wrote: Hi All OCXO’s are sensitive to acceleration. Gravity is one form of acceleration. A sensitivity in the 0.5 to 2 ppb / G is not uncommon. Bob On May 11, 2015, at 9:24 PM, J. L. Trantham jlt...@att.net wrote: I recently obtained a 53132A and added the HP Opt 010 High Stability Time Base option with a 10811 variant OCXO. I left it on for over a week and it, ultimately, seemed to slow down in its drift, with the displayed frequency, as it 'read' my GPSDO, slowly decreasing, suggesting that the Time Base was, slowly, increasing in frequency. I then removed the HP option and installed a Polish UHS Time Base option with a Morion DOCXO. After about 72 hours, it seemed to stabilize. I then 'calibrated' the 53132A by connecting my GPSDO to Channel 1. The displayed frequency was +/- 1 to 2 mHz of 10.000 000 000 MHz for the past week or so, with no drift noticeable. I had 'calibrated' the 53132A with it sitting at about +30 degrees, propped up on its 'handle' in a 'vertical' position. I then had occasion to move the 'handle' under the unit whereby the unit was 'flat', at which point the displayed frequency dropped to 9.999 999 997 MHz, +/- 1 to 2 mHz. The displayed frequency was the same this evening when I came home. When I again 'elevated' the unit by moving the handle to its more 'vertical' position, the displayed frequency moved to 10.000 000 000 MHz +/- 1 to 2 mHz. I'm not sure what this means. It is a 'repeatable' observation. It displayed the lower frequency all day and when I 'elevated' the 53132A this evening, the frequency again went to 10.000 000 000 Mhz. Is this a 'gravity' effect? Is this an issue with the DOCXO? Is this an issue with the 53132A? If I am correct in my calculations, the displayed frequency is +/- 1 to 2 parts in 10E-10 of 10 MHz, assuming my GPSDO is accurate and stable. Otherwise, the GPSDO and 53132A 'drift' is exactly the same. I would appreciate anyone's thoughts regarding this analysis and observation and how to go about 'quantifying' it in a more scientific method, assuming it's worth pursuing. Thanks in advance. Joe ___ time-nuts mailing 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] TTi TF930/960 linux programming
Hi guys, I seem to recall that someone on this list mentioned that he's using a Thurlby-Tandar TF930 or 960 Frequency counter. As I'm considering to buy such a unit for some experiments at my workplace, I figured I'd better ask around here for some suggestions. Has someone already used one of these gadgets in a computer-controlled fashion, with some luck using some Linux environment? Judging from the manual, I probably ccould hack some shell script to repeatedly perform frequency readings and write that to a file, but if someone already has done that I'd be much too lazy to reinvent the wheel... The actual setting I'd plan to use it in is to monitor some ring oscillators (frequency drift) and/or delay lines (output pulse length) sort-of-continuously over extended periods of time. I'd be interested in frequency drifts due to device aging and/or radiation effects, and as especially device aging tests can take quite some time (a few months each...), some sort of stability would be needed. This is not strictly a time-nuts application where one might chase the 10th digit, and I figure I probably could tolerate (and wouldn't even notice without cross-checking) an constant offset in frequency readings even of a few percent, but it would bite me quite a bit if the readings wander around too much when the input frequency doesn't... Any suggestions? best regards, Florian ___ time-nuts mailing 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] 53132A Polish UHS Time Base Option Interesting Ovservation
Hi The answer to any complicated question is always going to be “that depends” … You can indeed buy acceleration compensated OCXO’s. You can get them that only compensate simple (DC) acceleration or that compensate vibration as well. It all depends on the requirements of your system. Bob On May 12, 2015, at 11:49 AM, D W watsondani...@gmail.com wrote: And this is where one question leads to another. For an oscillator that is going to be used at very high velocities and accelerations, like in a missile, would it be calibrated somehow under the target G force? Or would you just compensate some other way? Or just not worry about it? Dan On May 12, 2015, at 6:51 AM, Bob Camp kb...@n1k.org wrote: Hi All OCXO’s are sensitive to acceleration. Gravity is one form of acceleration. A sensitivity in the 0.5 to 2 ppb / G is not uncommon. Bob On May 11, 2015, at 9:24 PM, J. L. Trantham jlt...@att.net wrote: I recently obtained a 53132A and added the HP Opt 010 High Stability Time Base option with a 10811 variant OCXO. I left it on for over a week and it, ultimately, seemed to slow down in its drift, with the displayed frequency, as it 'read' my GPSDO, slowly decreasing, suggesting that the Time Base was, slowly, increasing in frequency. I then removed the HP option and installed a Polish UHS Time Base option with a Morion DOCXO. After about 72 hours, it seemed to stabilize. I then 'calibrated' the 53132A by connecting my GPSDO to Channel 1. The displayed frequency was +/- 1 to 2 mHz of 10.000 000 000 MHz for the past week or so, with no drift noticeable. I had 'calibrated' the 53132A with it sitting at about +30 degrees, propped up on its 'handle' in a 'vertical' position. I then had occasion to move the 'handle' under the unit whereby the unit was 'flat', at which point the displayed frequency dropped to 9.999 999 997 MHz, +/- 1 to 2 mHz. The displayed frequency was the same this evening when I came home. When I again 'elevated' the unit by moving the handle to its more 'vertical' position, the displayed frequency moved to 10.000 000 000 MHz +/- 1 to 2 mHz. I'm not sure what this means. It is a 'repeatable' observation. It displayed the lower frequency all day and when I 'elevated' the 53132A this evening, the frequency again went to 10.000 000 000 Mhz. Is this a 'gravity' effect? Is this an issue with the DOCXO? Is this an issue with the 53132A? If I am correct in my calculations, the displayed frequency is +/- 1 to 2 parts in 10E-10 of 10 MHz, assuming my GPSDO is accurate and stable. Otherwise, the GPSDO and 53132A 'drift' is exactly the same. I would appreciate anyone's thoughts regarding this analysis and observation and how to go about 'quantifying' it in a more scientific method, assuming it's worth pursuing. Thanks in advance. Joe ___ time-nuts mailing 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] 53132A Polish UHS Time Base Option Interesting Ovservation
Hi All OCXO’s are sensitive to acceleration. Gravity is one form of acceleration. A sensitivity in the 0.5 to 2 ppb / G is not uncommon. Bob On May 11, 2015, at 9:24 PM, J. L. Trantham jlt...@att.net wrote: I recently obtained a 53132A and added the HP Opt 010 High Stability Time Base option with a 10811 variant OCXO. I left it on for over a week and it, ultimately, seemed to slow down in its drift, with the displayed frequency, as it 'read' my GPSDO, slowly decreasing, suggesting that the Time Base was, slowly, increasing in frequency. I then removed the HP option and installed a Polish UHS Time Base option with a Morion DOCXO. After about 72 hours, it seemed to stabilize. I then 'calibrated' the 53132A by connecting my GPSDO to Channel 1. The displayed frequency was +/- 1 to 2 mHz of 10.000 000 000 MHz for the past week or so, with no drift noticeable. I had 'calibrated' the 53132A with it sitting at about +30 degrees, propped up on its 'handle' in a 'vertical' position. I then had occasion to move the 'handle' under the unit whereby the unit was 'flat', at which point the displayed frequency dropped to 9.999 999 997 MHz, +/- 1 to 2 mHz. The displayed frequency was the same this evening when I came home. When I again 'elevated' the unit by moving the handle to its more 'vertical' position, the displayed frequency moved to 10.000 000 000 MHz +/- 1 to 2 mHz. I'm not sure what this means. It is a 'repeatable' observation. It displayed the lower frequency all day and when I 'elevated' the 53132A this evening, the frequency again went to 10.000 000 000 Mhz. Is this a 'gravity' effect? Is this an issue with the DOCXO? Is this an issue with the 53132A? If I am correct in my calculations, the displayed frequency is +/- 1 to 2 parts in 10E-10 of 10 MHz, assuming my GPSDO is accurate and stable. Otherwise, the GPSDO and 53132A 'drift' is exactly the same. I would appreciate anyone's thoughts regarding this analysis and observation and how to go about 'quantifying' it in a more scientific method, assuming it's worth pursuing. Thanks in advance. Joe ___ time-nuts mailing 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] 53132A Polish UHS Time Base Option Interesting Ovservation
Hi Joe... Just to show off that I've learned a thing or two in the 6-8 years I've been subscribed to this list, I will venture to say that the culprit is the direction of the gravity vector through the oscillator. I recall a couple of guys talking about the frequency change of their Morion's when flipped 180 degrees. But, it could be an interference issue as well, like hum pickup from lights or the like, but I don’t know what the magnitude of that effect would be. Tom Holmes, N8ZM -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of J. L. Trantham Sent: Monday, May 11, 2015 9:25 PM To: Discussion of precise time and frequency measurement Subject: [time-nuts] 53132A Polish UHS Time Base Option Interesting Ovservation I recently obtained a 53132A and added the HP Opt 010 High Stability Time Base option with a 10811 variant OCXO. I left it on for over a week and it, ultimately, seemed to slow down in its drift, with the displayed frequency, as it 'read' my GPSDO, slowly decreasing, suggesting that the Time Base was, slowly, increasing in frequency. I then removed the HP option and installed a Polish UHS Time Base option with a Morion DOCXO. After about 72 hours, it seemed to stabilize. I then 'calibrated' the 53132A by connecting my GPSDO to Channel 1. The displayed frequency was +/- 1 to 2 mHz of 10.000 000 000 MHz for the past week or so, with no drift noticeable. I had 'calibrated' the 53132A with it sitting at about +30 degrees, propped up on its 'handle' in a 'vertical' position. I then had occasion to move the 'handle' under the unit whereby the unit was 'flat', at which point the displayed frequency dropped to 9.999 999 997 MHz, +/- 1 to 2 mHz. The displayed frequency was the same this evening when I came home. When I again 'elevated' the unit by moving the handle to its more 'vertical' position, the displayed frequency moved to 10.000 000 000 MHz +/- 1 to 2 mHz. I'm not sure what this means. It is a 'repeatable' observation. It displayed the lower frequency all day and when I 'elevated' the 53132A this evening, the frequency again went to 10.000 000 000 Mhz. Is this a 'gravity' effect? Is this an issue with the DOCXO? Is this an issue with the 53132A? If I am correct in my calculations, the displayed frequency is +/- 1 to 2 parts in 10E-10 of 10 MHz, assuming my GPSDO is accurate and stable. Otherwise, the GPSDO and 53132A 'drift' is exactly the same. I would appreciate anyone's thoughts regarding this analysis and observation and how to go about 'quantifying' it in a more scientific method, assuming it's worth pursuing. Thanks in advance. Joe ___ time-nuts mailing 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] 53132A Polish UHS Time Base Option Interesting Ovservation
On 12/05/2015 11:24 AM, J. L. Trantham wrote: [snip] It is a 'repeatable' observation. It displayed the lower frequency all day and when I 'elevated' the 53132A this evening, the frequency again went to 10.000 000 000 Mhz. Is this a 'gravity' effect? Is this an issue with the DOCXO? Is this an issue with the 53132A? If I am correct in my calculations, the displayed frequency is +/- 1 to 2 parts in 10E-10 of 10 MHz, assuming my GPSDO is accurate and stable. Otherwise, the GPSDO and 53132A 'drift' is exactly the same. Gravity :) For an explanation... http://www.eevblog.com/2014/07/31/eevblog-646-gravity-detection-using-a-frequency-counter/ regards Tim -- VK2XAX :: QF56if23 :: BMARC :: WIA :: AMSATVK ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
