Re: [time-nuts] hp5065b !!!
On Sat, 04 May 2013 22:00:36 -0700 Hal Murray hmur...@megapathdsl.net wrote: mspencer12...@yahoo.ca said: Hi, while skimming some articles I found re GPS satellites, I found some references to certain buffer gasses in Rb cells working much better with optical filters than others. As far as I know Rb buffer gas formulations are not disclosed by the manufacturers so I suspect this info may not be very actionable for those of us looking to improve our Rb's. How hard would it be to measure the content of the buffer gas? I've watched while somebody else did X-ray crystallography. Is there something of similar complexity that would work with the gas in it's handy container or would you have to break one? Non-destructive would be quite hard. The buffer gas is usally N and/or one or two of the noble gases[1]. So X-ray crystalography doesn't work. NMR and IR spectroscopy would get you the types of gases. But one of the important factors is the exact ratio of the mixture. Different gasses give different temperature and pressure shift coefficients. And mixture ratios are used to cancel these out. Attila Kinali [1] I know i have some papers which anylse different buffer gasses, but i cannot find them. I also have never seen anyone mention non-elementary gasses like CO2. -- The people on 4chan are like brilliant psychologists who also happen to be insane and gross. -- unknown ___ 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] hp5065b !!!
On Sun, 5 May 2013 09:53:31 +0200 Attila Kinali att...@kinali.ch wrote: [1] I know i have some papers which anylse different buffer gasses, but i cannot find them. I also have never seen anyone mention non-elementary gasses like CO2. Correction. I just remembered reading somewhere, someone using a methane mixture as buffer gas. And a quick google revieled that methane, ethane and ethylene/ethene being sold as buffer gases. Though i must say, i'm not sure i would use ethene as buffer gas for an alkali metal, it being quite reactive.. Attila Kinali -- The people on 4chan are like brilliant psychologists who also happen to be insane and gross. -- unknown ___ 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] hp5065b !!!
Hi, while skimming some articles I found re GPS satellites, I found some references to certain buffer gasses in Rb cells working much better with optical filters than others. As far as I know Rb buffer gas formulations are not disclosed by the manufacturers so I suspect this info may not be very actionable for those of us looking to improve our Rb's. This has been a useful diversion to some academic stuff I'm dealing with this weekend (: All the best Mark S ___ 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] hp5065b !!!
Hi Buffer gas combo's are he voodoo of Rb cells. You can fiddle them to impact the temperature coefficient of the cell. They can also improve the degradation from impact with the cell walls. The Efratom boys came up with a way to improve filtering with a buffer gas mixture. Bob On May 4, 2013, at 8:37 PM, Mark Spencer mspencer12...@yahoo.ca wrote: Hi, while skimming some articles I found re GPS satellites, I found some references to certain buffer gasses in Rb cells working much better with optical filters than others. As far as I know Rb buffer gas formulations are not disclosed by the manufacturers so I suspect this info may not be very actionable for those of us looking to improve our Rb's. This has been a useful diversion to some academic stuff I'm dealing with this weekend (: All the best Mark S ___ 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] hp5065b !!!
Hi, Buffert gas slows down the rubidium atoms, which increases the Q value. Already that is an important factor in the performance of rubidiums. Then, the inevitable wall-shift can be first degree compensated by the buffer gas mixture, and in there can the details of the RF synthesis be compensated to suitable range. Toss in the concerns of modern times that Bob mentioned and you start to see that it is quite a few issues in there. Also, the buffer gas in the lamp and in the reference cell is two separate things. Cheers, Magnus On 05/05/2013 02:48 AM, Bob Camp wrote: Hi Buffer gas combo's are he voodoo of Rb cells. You can fiddle them to impact the temperature coefficient of the cell. They can also improve the degradation from impact with the cell walls. The Efratom boys came up with a way to improve filtering with a buffer gas mixture. Bob On May 4, 2013, at 8:37 PM, Mark Spencermspencer12...@yahoo.ca wrote: Hi, while skimming some articles I found re GPS satellites, I found some references to certain buffer gasses in Rb cells working much better with optical filters than others. As far as I know Rb buffer gas formulations are not disclosed by the manufacturers so I suspect this info may not be very actionable for those of us looking to improve our Rb's. This has been a useful diversion to some academic stuff I'm dealing with this weekend (: All the best Mark S ___ 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] hp5065b !!!
Corby, See p177. http://www.pttimeeting.org/archivemeetings/2002papers/paper18.pdf I found other references that said basically the same thing.. If you would like more info please contact me off list and I can likely send you some more URL's. Regards Mark S ___ 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] hp5065b !!!
mspencer12...@yahoo.ca said: Hi, while skimming some articles I found re GPS satellites, I found some references to certain buffer gasses in Rb cells working much better with optical filters than others. As far as I know Rb buffer gas formulations are not disclosed by the manufacturers so I suspect this info may not be very actionable for those of us looking to improve our Rb's. How hard would it be to measure the content of the buffer gas? I've watched while somebody else did X-ray crystallography. Is there something of similar complexity that would work with the gas in it's handy container or would you have to break one? This was early 70s, long before PCs. Our recipe was roughly: Pulverize sample. Put some of the powder in a X-ray setup. Wiggle arm to find peak. Adjust gain so peak is 1.00. Push the button that scans over angle and makes a paper chart of intensity vs angle. Find the 3 biggest peaks. Look those angles up in the (big) book. Look that crystal up in the card catalog which lists all sorts of info for a crystal including a list of angle/intensity pairs. Check all the minor peaks. We were lucky and had a close-to-pure crystal so we didn't have to iterate. -- These are my opinions. I hate spam. ___ 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] hp5065b !!!
I'm interested in these improvements too, and hope some can be applied to other models. I don't have a 5065A, nor do I expect to ever get one, but I do have three identical old Efratom units. Whether it's worthwhile to modify any Rb units also depends on whether it's possible to rejuvenate their Rb lamps, as discussed here a number of times, so that they can be maintained virtually indefinitely. Ed ___ 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] hp5065b !!!
Hi One of the unique things about the 5065 is it's great big cells. The small cell compact Rb's are a very different beast. There is a body of evidence suggesting that the cell size is significant for ultra low ADEV. The basic concepts of improving signal (light intensity) and signal to noise (filtering) would apply to other units. Weather the mods give significant improvements on small cells is the open question. The compact Rb's may already be at the floor for their cell size…. Bob On May 3, 2013, at 10:40 AM, ed breya e...@telight.com wrote: I'm interested in these improvements too, and hope some can be applied to other models. I don't have a 5065A, nor do I expect to ever get one, but I do have three identical old Efratom units. Whether it's worthwhile to modify any Rb units also depends on whether it's possible to rejuvenate their Rb lamps, as discussed here a number of times, so that they can be maintained virtually indefinitely. Ed ___ 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] hp5065b !!!
In message bb988fb5-d829-4c9d-a8bd-f2c8731b8...@rtty.us, Bob Camp writes: The basic concepts of improving signal (light intensity) and signal to noise (filtering) would apply to other units. I was wondering about that. The normally quoted number for change in (detected) light intensity is approx 0.1%. It would be interesting to find out if this changes significantly with the extra filtering ? If so, that would likely help smaller cells more than big cells... -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ 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] hp5065b !!!
Great big and small Rb cells: http://leapsecond.com/corby/rb-lamp.htm Also: http://leapsecond.com/corby/5065a-optical/ /tvb - Original Message - From: Bob Camp li...@rtty.us To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Friday, May 03, 2013 10:07 AM Subject: Re: [time-nuts] hp5065b !!! Hi One of the unique things about the 5065 is it's great big cells. The small cell compact Rb's are a very different beast. There is a body of evidence suggesting that the cell size is significant for ultra low ADEV. The basic concepts of improving signal (light intensity) and signal to noise (filtering) would apply to other units. Weather the mods give significant improvements on small cells is the open question. The compact Rb's may already be at the floor for their cell size…. Bob On May 3, 2013, at 10:40 AM, ed breya e...@telight.com wrote: I'm interested in these improvements too, and hope some can be applied to other models. I don't have a 5065A, nor do I expect to ever get one, but I do have three identical old Efratom units. Whether it's worthwhile to modify any Rb units also depends on whether it's possible to rejuvenate their Rb lamps, as discussed here a number of times, so that they can be maintained virtually indefinitely. Ed ___ 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] hp5065b !!!
I have a question for the list that I'm sure Corby can address but perhaps someone else can explain as well. Corby notes that this mod has only been effective with late series A3 modules. My question is: what change did HP make to the A3 module (early to late) that affects the mod Corby is making? I do not own a 5065 and the the only manual I have found on the web omits the pages related to the A3 multiplier so I'm not sure of it's exact function: I assume it generates the phase modulated 6.8 GHz? Thanks, Bob Darby ___ 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] hp5065b !!!
Hi There is a lot of differences between SRD's in terms of flicker / shot noise. I'd bet they changed the multiplier design. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Robert Darby Sent: Wednesday, May 01, 2013 7:25 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] hp5065b !!! I have a question for the list that I'm sure Corby can address but perhaps someone else can explain as well. Corby notes that this mod has only been effective with late series A3 modules. My question is: what change did HP make to the A3 module (early to late) that affects the mod Corby is making? I do not own a 5065 and the the only manual I have found on the web omits the pages related to the A3 multiplier so I'm not sure of it's exact function: I assume it generates the phase modulated 6.8 GHz? Thanks, Bob Darby ___ 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] HP5065B !!!
On 04/29/2013 11:19 PM, ewkeh...@aol.com wrote: I am still sitting here trying to figure out the purpose of posting the article on laser diode pumping of the Rb. One look at the data and it is clear that Corby’s work far surpasses the data shown in the paper. All it does is distract from Corb’s accomplishments. You are over-reacting. Common thread is really cleaner pumping action. Providing better filter or other pumping source is among the same range of improvements. It is not to dismiss Corbys work, rather thinking about the same basic approach, but implemented in another way. What I think is interesting is that it could point to the problem with maintaining the filter cell aligned with the lamp cell, which in itself is an approximation of a filter anyway. I have not seen any rubidium which automatically steer this alignment. Lets be clear, Corby has opened the door of H Maser performance for those that have a HP 5065A. Not all work is done but a giant step has been accomplished, the challenge now is to continue the work. In simple terms it gets down to keep the A/V slope from turning upward. Work is going on off list to address some of the issues and maybe some one is willing to contribute. But what the list at a whole can do is contribute data as to HP 5065A performance. There are quite a few 5065A’s out there but very little data besides HP spec. To better tackle the flattening of the curve, aging, temperature sensitivity, barometric pressure sensitivity and even humidity sensitivity has to be understood. It is unrealistic to get past 1 E-13 unless this is understood and compensated for. Also some of these parameters will vary from unit to unit and some degree of tailoring to a particular unit has to be considered in the design. Some tests have to be done by those members that have access to a Maser. Also Corby found out that units with older A3 modules did not get the performance boost but replacement of A3 did get the super performance. That confirms my suspicion that there is room for work on frequency generation. PRS 10 does a direct frequency generation. Somehow using the step recovery diode as a mixer obviously works but is it optimum, or is there a better way to generate the resonator frequency? What is key to get the best signal and S/N ratio? Locking a YIG? See HP5071A paper for that purpose. When previously mentioning aging control, concern was voiced as to getting in to the HP 5065A. Corby’s work gets to the hart of the unit, the RVFR, but Corby has gone four for four. Adding control will only move the two C field wires to the analog board and using 30 mA from the unit. Unit can easily restored to its original condition as far as frequency control is concerned. Obviously the RVFR is the big differentiator in the HP5065A and I know of no commercially available unit that even gets close but once the work is complete a look at a FRK may be in order, I doubt it will ever be as good, but there is room for a filter and the physics part is considerable larger than today’s units. Some other units may be using a filter but the physics package is so small that compromises had to be made and the goal was more cost than ultimate performance. It is up to the list to turn this in to a Maser like performance with out mortgaging your home. If I get more details how I should modify my HP5065As I would consider it. Cheers, Magnus ___ 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] HP5065B !!!
On 04/30/2013 03:38 AM, ewkeh...@aol.com wrote: I never came to that conclusion. There is enough work out there with results. My comment was to that particular paper that did not measure up to the work Corby has been doing. Still trying to figure out the purpose of the posting. Bert Kehren Well, it is comparing apples to oranges. So many other things changed that you can't compare it directly to Corbys work on the HP5065As. What you can draw conclusions from is relative changes within a particular design limit as you alter the design, draw some conclusions and then consider what it could do on another design. So, it is a relevant thing to discuss, as a possible next step to look at, which is not to degrade at all the work being done. It can also turn out that for it to pan out as better, it comes at a much higher cost or has only marginally improvements, so Corbys change is better bang for the buck. Cheers, Magnus In a message dated 4/29/2013 6:34:24 P.M. Eastern Daylight Time, bruce.griffi...@xtra.co.nz writes: Since performance improves as the bandwidth of the lamp spectrum decreases its not unreasonble to suggest that a suitable laser source may improve performance further. The following paper (and theoretical considerations) indicate that your conclusions regarding the potential performance of a laser pumped rubidium standard are incorrect. http://tf.boulder.nist.gov/general/pdf/1219.pdf The addition of second harmonic traps tuned to the 2nd harmonic of the modulation frequency of the resonance interrogation signals should improve the performance considerably. Bruce ewkeh...@aol.com wrote: I am still sitting here trying to figure out the purpose of posting the article on laser diode pumping of the Rb. One look at the data and it is clear that Corby’s work far surpasses the data shown in the paper. All it does is distract from Corb’s accomplishments. Lets be clear, Corby has opened the door of H Maser performance for those that have a HP 5065A. Not all work is done but a giant step has been accomplished, the challenge now is to continue the work. In simple terms it gets down to keep the A/V slope from turning upward. Work is going on off list to address some of the issues and maybe some one is willing to contribute. But what the list at a whole can do is contribute data as to HP 5065A performance. There are quite a few 5065A’s out there but very little data besides HP spec. To better tackle the flattening of the curve, aging, temperature sensitivity, barometric pressure sensitivity and even humidity sensitivity has to be understood. It is unrealistic to get past 1 E-13 unless this is understood and compensated for. Also some of these parameters will vary from unit to unit and some degree of tailoring to a particular unit has to be considered in the design. Some tests have to be done by those members that have access to a Maser. Also Corby found out that units with older A3 modules did not get the performance boost but replacement of A3 did get the super performance. That confirms my suspicion that there is room for work on frequency generation. PRS 10 does a direct frequency generation. Somehow using the step recovery diode as a mixer obviously works but is it optimum, or is there a better way to generate the resonator frequency? What is key to get the best signal and S/N ratio? When previously mentioning aging control, concern was voiced as to getting in to the HP 5065A. Corby’s work gets to the hart of the unit, the RVFR, but Corby has gone four for four. Adding control will only move the two C field wires to the analog board and using 30 mA from the unit. Unit can easily restored to its original condition as far as frequency control is concerned. Obviously the RVFR is the big differentiator in the HP5065A and I know of no commercially available unit that even gets close but once the work is complete a look at a FRK may be in order, I doubt it will ever be as good, but there is room for a filter and the physics part is considerable larger than today’s units. Some other units may be using a filter but the physics package is so small that compromises had to be made and the goal was more cost than ultimate performance. It is up to the list to turn this in to a Maser like performance with out mortgaging your home. Bert Kehren ___ 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
Re: [time-nuts] hp5065b !!!
Bob, all of the manual donloads appear to be the Nov. 1979 version only. The A3 board is on pages 8-22 ff. There is a high resolution 3 vol version scanned by Brian Kirby KD4FN standing out http://www.kennethkuhn.com/hpmuseum/scans/ Anyone has a later manual version? I would much appreciate to get the late A3 version pages. I have to say that Corby's modification in its simplicity and achieved improvement is absolutely ingenious. Adrian Robert Darby schrieb: I have a question for the list that I'm sure Corby can address but perhaps someone else can explain as well. Corby notes that this mod has only been effective with late series A3 modules. My question is: what change did HP make to the A3 module (early to late) that affects the mod Corby is making? I do not own a 5065 and the the only manual I have found on the web omits the pages related to the A3 multiplier so I'm not sure of it's exact function: I assume it generates the phase modulated 6.8 GHz? Thanks, Bob Darby ___ 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] hp5065b !!!
The multiplier and output has been changed significantly. We can not put a finger on one part but if you reed the paper . http://tf.boulder.nist.gov/general/pdf/1219.pdf that Bruce posted it does explain the RF significance.I ignored the laser part since I will not be able to duplicate, but the microwave part clearly outlines its contribution to performance. Right now we are doing it off list since there seems not to be much interest in having H Maser like performance at home. Bert In a message dated 5/1/2013 8:13:24 A.M. Eastern Daylight Time, bobda...@triad.rr.com writes: I have a question for the list that I'm sure Corby can address but perhaps someone else can explain as well. Corby notes that this mod has only been effective with late series A3 modules. My question is: what change did HP make to the A3 module (early to late) that affects the mod Corby is making? I do not own a 5065 and the the only manual I have found on the web omits the pages related to the A3 multiplier so I'm not sure of it's exact function: I assume it generates the phase modulated 6.8 GHz? Thanks, Bob Darby ___ 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] hp5065b !!!
On 05/01/2013 03:26 PM, ewkeh...@aol.com wrote: The multiplier and output has been changed significantly. We can not put a finger on one part but if you reed the paper . http://tf.boulder.nist.gov/general/pdf/1219.pdf that Bruce posted it does explain the RF significance.I ignored the laser part since I will not be able to duplicate, but the microwave part clearly outlines its contribution to performance. Right now we are doing it off list since there seems not to be much interest in having H Maser like performance at home. There is at least from me, and I know others reads with interest. Remember that many remains silent on the list even if they read it with interest, so number of replies does not reflect interest. Cheers, Magnus ___ 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] hp5065b !!!
Adrian, Thanks for the link. The manual I had was simply missing all details related to the A3 module but this is superb. And yes, it would be nice to see the later version. Bert, I'm sure most everyone would like to have the level of performance demonstrated by the Corby modified 5065's. As Magnus has stated there is probably great interest on the list but many of us can't contribute in any meaningful way. Keep us posted. My question re the A3 module is related to the fact that an upgrade there appears to be necessary to take advantage of Corby's mod. I don't know the numbers of early versus late A3 modules but upgrades there may be necessary for many (or most?) owners to take advantage of his work. Also, is a change to the later A3 module a standalone improvement or were there systematic upgrades throughout the entire system to go with the newer A3 module? Is it practical to reverse engineer the later modules? Regards, Bob Darby On 5/1/2013 8:41 AM, Adrian wrote: Bob, all of the manual donloads appear to be the Nov. 1979 version only. The A3 board is on pages 8-22 ff. There is a high resolution 3 vol version scanned by Brian Kirby KD4FN standing out http://www.kennethkuhn.com/hpmuseum/scans/ Anyone has a later manual version? I would much appreciate to get the late A3 version pages. I have to say that Corby's modification in its simplicity and achieved improvement is absolutely ingenious. Adrian Robert Darby schrieb: I have a question for the list that I'm sure Corby can address but perhaps someone else can explain as well. Corby notes that this mod has only been effective with late series A3 modules. My question is: what change did HP make to the A3 module (early to late) that affects the mod Corby is making? I do not own a 5065 and the the only manual I have found on the web omits the pages related to the A3 multiplier so I'm not sure of it's exact function: I assume it generates the phase modulated 6.8 GHz? Thanks, Bob Darby ___ 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] hp5065b !!!
Corby, Thanks. Hit send just as your post came in. :o( I'm sure it will be interesting to see those changes. Bob On 5/1/2013 11:59 AM, cdel...@juno.com wrote: Bob, The new style A3 uses the same input and slighly modified output stages from the original. The multiplication from 5 to 60 Mhz is done entirely different. I have two scans that copy the schematic but they are way big in size. I'll experiment and try to make them small enough to email. Corby ___ 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] hp5065b !!!
Another factor that limits the (apparent) interest is that the 5065B is one of the most expensive and hardest to find Rb standards around. Even on the used market the price for a 5065B in good condition can be breathtaking. If Corby's work can be extended to other, more common units, the level of interest will explode. The question, of course, is whether the more common units will see any improvement. Since not all 5065B units show the same improvement, I won't be holding my breath! :-) Ed On 5/1/2013 9:13 AM, Magnus Danielson wrote: On 05/01/2013 03:26 PM, ewkeh...@aol.com wrote: The multiplier and output has been changed significantly. We can not put a finger on one part but if you reed the paper . http://tf.boulder.nist.gov/general/pdf/1219.pdf that Bruce posted it does explain the RF significance.I ignored the laser part since I will not be able to duplicate, but the microwave part clearly outlines its contribution to performance. Right now we are doing it off list since there seems not to be much interest in having H Maser like performance at home. There is at least from me, and I know others reads with interest. Remember that many remains silent on the list even if they read it with interest, so number of replies does not reflect interest. Cheers, Magnus ___ 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] hp5065b !!!
I agree with Magnus; I find it interesting to learn more about what can be done at the non-industrial level just for fun. But I certainly will not attempt to add to the discussion on a subject where I have no expertise, only curiosity. I am fascinated that there is the capability at the hobby level to improve significantly on what is a darn good timepiece to start with. Tom Holmes, N8ZM Tipp City, OH EM79 -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Magnus Danielson Sent: Wednesday, May 01, 2013 11:13 AM To: time-nuts@febo.com Subject: Re: [time-nuts] hp5065b !!! On 05/01/2013 03:26 PM, ewkeh...@aol.com wrote: The multiplier and output has been changed significantly. We can not put a finger on one part but if you reed the paper . http://tf.boulder.nist.gov/general/pdf/1219.pdf that Bruce posted it does explain the RF significance.I ignored the laser part since I will not be able to duplicate, but the microwave part clearly outlines its contribution to performance. Right now we are doing it off list since there seems not to be much interest in having H Maser like performance at home. There is at least from me, and I know others reads with interest. Remember that many remains silent on the list even if they read it with interest, so number of replies does not reflect interest. Cheers, Magnus ___ 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] hp5065b !!!
On Wed, 1 May 2013 09:26:24 -0400 (EDT) ewkeh...@aol.com wrote: The multiplier and output has been changed significantly. We can not put a finger on one part but if you reed the paper . http://tf.boulder.nist.gov/general/pdf/1219.pdf that Bruce posted it does explain the RF significance.I ignored the laser part since I will not be able to duplicate, but the microwave part clearly outlines its contribution to performance. Right now we are doing it off list since there seems not to be much interest in having H Maser like performance at home. Uhmm.. actually, i would be interested in this discussion. I wont be able to reproduce it, due to lack of equipment, but i can definitly learn from you. Attila Kinali -- The people on 4chan are like brilliant psychologists who also happen to be insane and gross. -- unknown ___ 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] hp5065b !!!
On Wed, 1 May 2013 08:59:32 -0700 cdel...@juno.com wrote: The new style A3 uses the same input and slighly modified output stages from the original. The multiplication from 5 to 60 Mhz is done entirely different. I have two scans that copy the schematic but they are way big in size. I'll experiment and try to make them small enough to email. I think, there is enough interest in this schematics to warrant an upload to one of the usual sites. Attila Kinali -- The people on 4chan are like brilliant psychologists who also happen to be insane and gross. -- unknown ___ 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] hp5065b !!!
On a related note does any one know the likely serial number ranges of the HP5065's that would benefit from this treatment ? (Or is there any other easy way to tell the units appart ?) Thanks to all concerned for the effort put forwards on this project. It may sway me towards actually buying an HP5065 at some point in the future. The efforts are appreciated. Regards Mark S Message: 5 Date: Wed, 01 May 2013 11:58:58 -0600 From: Ed Palmer ed_pal...@sasktel.net To: time-nuts@febo.com Subject: Re: [time-nuts] hp5065b !!! Message-ID: 518157e2.2020...@sasktel.net Content-Type: text/plain; charset=ISO-8859-1; format=flowed Another factor that limits the (apparent) interest is that the 5065B is one of the most expensive and hardest to find Rb standards around. Even on the used market the price for a 5065B in good condition can be breathtaking. If Corby's work can be extended to other, more common units, the level of interest will explode. The question, of course, is whether the more common units will see any improvement. Since not all 5065B units show the same improvement, I won't be holding my breath! :-) Ed On 5/1/2013 9:13 AM, Magnus Danielson wrote: On 05/01/2013 03:26 PM, ewkeh...@aol.com wrote: The multiplier and output has been changed significantly. We can not put a finger on one part but if you reed the paper . http://tf.boulder.nist.gov/general/pdf/1219.pdf that Bruce posted it does explain the RF significance.I ignored the laser part since I will not be able to duplicate, but the microwave part clearly outlines its contribution to performance. Right now we are doing it off list since there seems not to be much interest in having H Maser like performance at home. There is at least from me, and I know others reads with interest. Remember that many remains silent on the list even if they read it with interest, so number of replies does not reflect interest. Cheers, Magnus ___ 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] hp5065b !!!
For the last two years some of us have ben knocking at the door trying to get passive H Maser like performance, well Corby kicked it in. More work is needed and it starts with the A3 module. I have spend hours comparing old and new and I am sure many of the old variety are out there. Nothing I can put my finger on and only some one that was there could most likely give the answer. How ever for the last two years I have been looking at the microwave signal generation and the recently posted paper confirms the importance of that part of the circuit. This is one of several areas where the group can make a contribution. What can be learned completing Corby's work may be applicable like in modifying a FRK. Would be next on my list. So work on the HP5065A can benefit other Rb's Bert Kehren In a message dated 5/1/2013 3:19:14 P.M. Eastern Daylight Time, bobda...@triad.rr.com writes: Adrian, Thanks for the link. The manual I had was simply missing all details related to the A3 module but this is superb. And yes, it would be nice to see the later version. Bert, I'm sure most everyone would like to have the level of performance demonstrated by the Corby modified 5065's. As Magnus has stated there is probably great interest on the list but many of us can't contribute in any meaningful way. Keep us posted. My question re the A3 module is related to the fact that an upgrade there appears to be necessary to take advantage of Corby's mod. I don't know the numbers of early versus late A3 modules but upgrades there may be necessary for many (or most?) owners to take advantage of his work. Also, is a change to the later A3 module a standalone improvement or were there systematic upgrades throughout the entire system to go with the newer A3 module? Is it practical to reverse engineer the later modules? Regards, Bob Darby On 5/1/2013 8:41 AM, Adrian wrote: Bob, all of the manual donloads appear to be the Nov. 1979 version only. The A3 board is on pages 8-22 ff. There is a high resolution 3 vol version scanned by Brian Kirby KD4FN standing out http://www.kennethkuhn.com/hpmuseum/scans/ Anyone has a later manual version? I would much appreciate to get the late A3 version pages. I have to say that Corby's modification in its simplicity and achieved improvement is absolutely ingenious. Adrian Robert Darby schrieb: I have a question for the list that I'm sure Corby can address but perhaps someone else can explain as well. Corby notes that this mod has only been effective with late series A3 modules. My question is: what change did HP make to the A3 module (early to late) that affects the mod Corby is making? I do not own a 5065 and the the only manual I have found on the web omits the pages related to the A3 multiplier so I'm not sure of it's exact function: I assume it generates the phase modulated 6.8 GHz? Thanks, Bob Darby ___ 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] hp5065b !!!
Keeping these discussions on list would be quite helpful for us lurkers that try to glean as much information as possible from the posts. While I may not have the expertise to contribute often, I value the insight provided by others. In addition, discussing on list has the benefit of having the messages archived and searchable. I've learned alot (but not nearly enough) by searching the archives for various topics. Please consider keeping such discussions on list. Paul On May 1, 2013, at 11:13, Magnus Danielson mag...@rubidium.dyndns.org wrote: On 05/01/2013 03:26 PM, ewkeh...@aol.com wrote: The multiplier and output has been changed significantly. We can not put a finger on one part but if you reed the paper . http://tf.boulder.nist.gov/general/pdf/1219.pdf that Bruce posted it does explain the RF significance.I ignored the laser part since I will not be able to duplicate, but the microwave part clearly outlines its contribution to performance. Right now we are doing it off list since there seems not to be much interest in having H Maser like performance at home. There is at least from me, and I know others reads with interest. Remember that many remains silent on the list even if they read it with interest, so number of replies does not reflect interest. Cheers, Magnus ___ 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] hp5065b !!!
I think it starts with 22 Corby will be able to tell you tomorrow. But do not forget even earlier models will benefit with a work around of A3. Its all in the RVFR. Bert Kehren In a message dated 5/1/2013 6:12:27 P.M. Eastern Daylight Time, mspencer12...@yahoo.ca writes: On a related note does any one know the likely serial number ranges of the HP5065's that would benefit from this treatment ? (Or is there any other easy way to tell the units appart ?) Thanks to all concerned for the effort put forwards on this project.It may sway me towards actually buying an HP5065 at some point in the future. The efforts are appreciated. Regards Mark S Message: 5 Date: Wed, 01 May 2013 11:58:58 -0600 From: Ed Palmer ed_pal...@sasktel.net To: time-nuts@febo.com Subject: Re: [time-nuts] hp5065b !!! Message-ID: 518157e2.2020...@sasktel.net Content-Type: text/plain; charset=ISO-8859-1; format=flowed Another factor that limits the (apparent) interest is that the 5065B is one of the most expensive and hardest to find Rb standards around. Even on the used market the price for a 5065B in good condition can be breathtaking. If Corby's work can be extended to other, more common units, the level of interest will explode. The question, of course, is whether the more common units will see any improvement. Since not all 5065B units show the same improvement, I won't be holding my breath! :-) Ed On 5/1/2013 9:13 AM, Magnus Danielson wrote: On 05/01/2013 03:26 PM, ewkeh...@aol.com wrote: The multiplier and output has been changed significantly. We can not put a finger on one part but if you reed the paper . http://tf.boulder.nist.gov/general/pdf/1219.pdf that Bruce posted it does explain the RF significance.I ignored the laser part since I will not be able to duplicate, but the microwave part clearly outlines its contribution to performance. Right now we are doing it off list since there seems not to be much interest in having H Maser like performance at home. There is at least from me, and I know others reads with interest. Remember that many remains silent on the list even if they read it with interest, so number of replies does not reflect interest. Cheers, Magnus ___ 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] HP5065B !!!
That paper appeared to describe how a laser is used to replace the rubidium lamp more completely than later papers that achieved better results. I should have also included links to later papers that better illustrate the performance that can be achieved. Bruce ewkeh...@aol.com wrote: I never came to that conclusion. There is enough work out there with results. My comment was to that particular paper that did not measure up to the work Corby has been doing. Still trying to figure out the purpose of the posting. Bert Kehren In a message dated 4/29/2013 6:34:24 P.M. Eastern Daylight Time, bruce.griffi...@xtra.co.nz writes: Since performance improves as the bandwidth of the lamp spectrum decreases its not unreasonble to suggest that a suitable laser source may improve performance further. The following paper (and theoretical considerations) indicate that your conclusions regarding the potential performance of a laser pumped rubidium standard are incorrect. http://tf.boulder.nist.gov/general/pdf/1219.pdf The addition of second harmonic traps tuned to the 2nd harmonic of the modulation frequency of the resonance interrogation signals should improve the performance considerably. Bruce ewkeh...@aol.com wrote: I am still sitting here trying to figure out the purpose of posting the article on laser diode pumping of the Rb. One look at the data and it is clear that Corby’s work far surpasses the data shown in the paper. All it does is distract from Corb’s accomplishments. Lets be clear, Corby has opened the door of H Maser performance for those that have a HP 5065A. Not all work is done but a giant step has been accomplished, the challenge now is to continue the work. In simple terms it gets down to keep the A/V slope from turning upward. Work is going on off list to address some of the issues and maybe some one is willing to contribute. But what the list at a whole can do is contribute data as to HP 5065A performance. There are quite a few 5065A’s out there but very little data besides HP spec. To better tackle the flattening of the curve, aging, temperature sensitivity, barometric pressure sensitivity and even humidity sensitivity has to be understood. It is unrealistic to get past 1 E-13 unless this is understood and compensated for. Also some of these parameters will vary from unit to unit and some degree of tailoring to a particular unit has to be considered in the design. Some tests have to be done by those members that have access to a Maser. Also Corby found out that units with older A3 modules did not get the performance boost but replacement of A3 did get the super performance. That confirms my suspicion that there is room for work on frequency generation. PRS 10 does a direct frequency generation. Somehow using the step recovery diode as a mixer obviously works but is it optimum, or is there a better way to generate the resonator frequency? What is key to get the best signal and S/N ratio? When previously mentioning aging control, concern was voiced as to getting in to the HP 5065A. Corby’s work gets to the hart of the unit, the RVFR, but Corby has gone four for four. Adding control will only move the two C field wires to the analog board and using 30 mA from the unit. Unit can easily restored to its original condition as far as frequency control is concerned. Obviously the RVFR is the big differentiator in the HP5065A and I know of no commercially available unit that even gets close but once the work is complete a look at a FRK may be in order, I doubt it will ever be as good, but there is room for a filter and the physics part is considerable larger than today’s units. Some other units may be using a filter but the physics package is so small that compromises had to be made and the goal was more cost than ultimate performance. It is up to the list to turn this in to a Maser like performance with out mortgaging your home. Bert Kehren ___ 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 --
Re: [time-nuts] HP5065B !!!
I rather agree with Bruce. What I have seen on recent improvements on laser diode accuracy/stability results seem to imply a rather large improvement is possible - and, as the HP5065A is a rather rare beast indeed on this side of the Atlantic, the excellent work done by Corby is not of direct relevance (except to prompt much experimenting..). Trying a stabilised laser diode source (and sacrificing one of my 'definitely not HP level' Rb units), in my particular case, seems like a very good alternative line of enquiry - even if I don't get quite as good results it will be fun! regards, Paul G8GJA -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of paul swed Sent: 30 April 2013 01:38 To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] HP5065B !!! I have to agree that the subjects really drifted. I am very excited about what seems like a reasonable effort to improve the 5065. Since I have one all the more interest. So I want to hear about the reflectors and concentrators and how they were added and then how the system may have been retuned to leverage the change. Have I accidently gotten on to the wrong thread?? If so can some one please point me to the correct thread? Thanks Paul WB8TSL On Mon, Apr 29, 2013 at 6:30 PM, Bruce Griffiths bruce.griffi...@xtra.co.nz wrote: Since performance improves as the bandwidth of the lamp spectrum decreases its not unreasonble to suggest that a suitable laser source may improve performance further. The following paper (and theoretical considerations) indicate that your conclusions regarding the potential performance of a laser pumped rubidium standard are incorrect. http://tf.boulder.nist.gov/**general/pdf/1219.pdfhttp://tf.boulder.nist.gov/general/pdf/1219.pdf The addition of second harmonic traps tuned to the 2nd harmonic of the modulation frequency of the resonance interrogation signals should improve the performance considerably. Bruce ewkeh...@aol.com wrote: I am still sitting here trying to figure out the purpose of posting the article on laser diode pumping of the Rb. One look at the data and it is clear that Corby's work far surpasses the data shown in the paper. All it does is distract from Corb's accomplishments. Lets be clear, Corby has opened the door of H Maser performance for those that have a HP 5065A. Not all work is done but a giant step has been accomplished, the challenge now is to continue the work. In simple terms it gets down to keep the A/V slope from turning upward. Work is going on off list to address some of the issues and maybe some one is willing to contribute. But what the list at a whole can do is contribute data as to HP 5065A performance. There are quite a few 5065A's out there but very little data besides HP spec. To better tackle the flattening of the curve, aging, temperature sensitivity, barometric pressure sensitivity and even humidity sensitivity has to be understood. It is unrealistic to get past 1 E-13 unless this is understood and compensated for. Also some of these parameters will vary from unit to unit and some degree of tailoring to a particular unit has to be considered in the design. Some tests have to be done by those members that have access to a Maser. Also Corby found out that units with older A3 modules did not get the performance boost but replacement of A3 did get the super performance. That confirms my suspicion that there is room for work on frequency generation. PRS 10 does a direct frequency generation. Somehow using the step recovery diode as a mixer obviously works but is it optimum, or is there a better way to generate the resonator frequency? What is key to get the best signal and S/N ratio? When previously mentioning aging control, concern was voiced as to getting in to the HP 5065A. Corby's work gets to the hart of the unit, the RVFR, but Corby has gone four for four. Adding control will only move the two C field wires to the analog board and using 30 mA from the unit. Unit can easily restored to its original condition as far as frequency control is concerned. Obviously the RVFR is the big differentiator in the HP5065A and I know of no commercially available unit that even gets close but once the work is complete a look at a FRK may be in order, I doubt it will ever be as good, but there is room for a filter and the physics part is considerable larger than today's units. Some other units may be using a filter but the physics package is so small that compromises had to be made and the goal was more cost than ultimate performance. It is up to the list to turn this in to a Maser like performance with out mortgaging your home. Bert Kehren __**_ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/** mailman
Re: [time-nuts] HP5065B !!!
Bruce Thank you for the second paper. It addresses also the generation of the microwave signal, critical to those of us that do not have the late A3 module. I do not want to discourage any one to experiment with laser diode pumping, but in the meantime it would be nice to work on flattening the curve on the Super HP5065A. There are at least fifty units in the time nuts community. Bert Kehren In a message dated 4/30/2013 2:05:40 A.M. Eastern Daylight Time, bruce.griffi...@xtra.co.nz writes: That paper appeared to describe how a laser is used to replace the rubidium lamp more completely than later papers that achieved better results. I should have also included links to later papers that better illustrate the performance that can be achieved. Bruce ewkeh...@aol.com wrote: I never came to that conclusion. There is enough work out there with results. My comment was to that particular paper that did not measure up to the work Corby has been doing. Still trying to figure out the purpose of the posting. Bert Kehren In a message dated 4/29/2013 6:34:24 P.M. Eastern Daylight Time, bruce.griffi...@xtra.co.nz writes: Since performance improves as the bandwidth of the lamp spectrum decreases its not unreasonble to suggest that a suitable laser source may improve performance further. The following paper (and theoretical considerations) indicate that your conclusions regarding the potential performance of a laser pumped rubidium standard are incorrect. http://tf.boulder.nist.gov/general/pdf/1219.pdf The addition of second harmonic traps tuned to the 2nd harmonic of the modulation frequency of the resonance interrogation signals should improve the performance considerably. Bruce ewkeh...@aol.com wrote: I am still sitting here trying to figure out the purpose of posting the article on laser diode pumping of the Rb. One look at the data and it is clear that Corby’s work far surpasses the data shown in the paper. All it does is distract from Corb’s accomplishments. Lets be clear, Corby has opened the door of H Maser performance for those that have a HP 5065A. Not all work is done but a giant step has been accomplished, the challenge now is to continue the work. In simple terms it gets down to keep the A/V slope from turning upward. Work is going on off list to address some of the issues and maybe some one is willing to contribute. But what the list at a whole can do is contribute data as to HP 5065A performance. There are quite a few 5065A’s out there but very little data besides HP spec. To better tackle the flattening of the curve, aging, temperature sensitivity, barometric pressure sensitivity and even humidity sensitivity has to be understood. It is unrealistic to get past 1 E-13 unless this is understood and compensated for. Also some of these parameters will vary from unit to unit and some degree of tailoring to a particular unit has to be considered in the design. Some tests have to be done by those members that have access to a Maser. Also Corby found out that units with older A3 modules did not get the performance boost but replacement of A3 did get the super performance. That confirms my suspicion that there is room for work on frequency generation. PRS 10 does a direct frequency generation. Somehow using the step recovery diode as a mixer obviously works but is it optimum, or is there a better way to generate the resonator frequency? What is key to get the best signal and S/N ratio? When previously mentioning aging control, concern was voiced as to getting in to the HP 5065A. Corby’s work gets to the hart of the unit, the RVFR, but Corby has gone four for four. Adding control will only move the two C field wires to the analog board and using 30 mA from the unit. Unit can easily restored to its original condition as far as frequency control is concerned. Obviously the RVFR is the big differentiator in the HP5065A and I know of no commercially available unit that even gets close but once the work is complete a look at a FRK may be in order, I doubt it will ever be as good, but there is room for a filter and the physics part is considerable larger than today’s units. Some other units may be using a filter but the physics package is so small that compromises had to be made and the goal was more cost than ultimate performance. It is up to the list to turn this in to a Maser like performance with out mortgaging your home. Bert Kehren ___
Re: [time-nuts] HP5065B !!!
Look forward to your test results. Bert Kehren In a message dated 4/30/2013 4:27:38 A.M. Eastern Daylight Time, paul.ree...@uk.thalesgroup.com writes: I rather agree with Bruce. What I have seen on recent improvements on laser diode accuracy/stability results seem to imply a rather large improvement is possible - and, as the HP5065A is a rather rare beast indeed on this side of the Atlantic, the excellent work done by Corby is not of direct relevance (except to prompt much experimenting..). Trying a stabilised laser diode source (and sacrificing one of my 'definitely not HP level' Rb units), in my particular case, seems like a very good alternative line of enquiry - even if I don't get quite as good results it will be fun! regards, Paul G8GJA -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of paul swed Sent: 30 April 2013 01:38 To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] HP5065B !!! I have to agree that the subjects really drifted. I am very excited about what seems like a reasonable effort to improve the 5065. Since I have one all the more interest. So I want to hear about the reflectors and concentrators and how they were added and then how the system may have been retuned to leverage the change. Have I accidently gotten on to the wrong thread?? If so can some one please point me to the correct thread? Thanks Paul WB8TSL On Mon, Apr 29, 2013 at 6:30 PM, Bruce Griffiths bruce.griffi...@xtra.co.nz wrote: Since performance improves as the bandwidth of the lamp spectrum decreases its not unreasonble to suggest that a suitable laser source may improve performance further. The following paper (and theoretical considerations) indicate that your conclusions regarding the potential performance of a laser pumped rubidium standard are incorrect. http://tf.boulder.nist.gov/**general/pdf/1219.pdfhttp://tf.boulder.nist.gov/general/pdf/1219.pdf The addition of second harmonic traps tuned to the 2nd harmonic of the modulation frequency of the resonance interrogation signals should improve the performance considerably. Bruce ewkeh...@aol.com wrote: I am still sitting here trying to figure out the purpose of posting the article on laser diode pumping of the Rb. One look at the data and it is clear that Corby's work far surpasses the data shown in the paper. All it does is distract from Corb's accomplishments. Lets be clear, Corby has opened the door of H Maser performance for those that have a HP 5065A. Not all work is done but a giant step has been accomplished, the challenge now is to continue the work. In simple terms it gets down to keep the A/V slope from turning upward. Work is going on off list to address some of the issues and maybe some one is willing to contribute. But what the list at a whole can do is contribute data as to HP 5065A performance. There are quite a few 5065A's out there but very little data besides HP spec. To better tackle the flattening of the curve, aging, temperature sensitivity, barometric pressure sensitivity and even humidity sensitivity has to be understood. It is unrealistic to get past 1 E-13 unless this is understood and compensated for. Also some of these parameters will vary from unit to unit and some degree of tailoring to a particular unit has to be considered in the design. Some tests have to be done by those members that have access to a Maser. Also Corby found out that units with older A3 modules did not get the performance boost but replacement of A3 did get the super performance. That confirms my suspicion that there is room for work on frequency generation. PRS 10 does a direct frequency generation. Somehow using the step recovery diode as a mixer obviously works but is it optimum, or is there a better way to generate the resonator frequency? What is key to get the best signal and S/N ratio? When previously mentioning aging control, concern was voiced as to getting in to the HP 5065A. Corby's work gets to the hart of the unit, the RVFR, but Corby has gone four for four. Adding control will only move the two C field wires to the analog board and using 30 mA from the unit. Unit can easily restored to its original condition as far as frequency control is concerned. Obviously the RVFR is the big differentiator in the HP5065A and I know of no commercially available unit that even gets close but once the work is complete a look at a FRK may be in order, I doubt it will ever be as good, but there is room for a filter and the physics part is considerable larger than today's units. Some other units may be using a filter but the physics package is so small that compromises had to be made and the goal was more cost than ultimate performance. It is up to the list
Re: [time-nuts] HP5065B !!!
On Mon, 29 Apr 2013 17:19:05 -0400 (EDT) ewkeh...@aol.com wrote: I am still sitting here trying to figure out the purpose of posting the article on laser diode pumping of the Rb. One look at the data and it is clear that Corby’s work far surpasses the data shown in the paper. All it does is distract from Corb’s accomplishments. Sorry i didnt mean to do that. I am very gratefull at the work Corby has done and the new insights on what error sources a Rb gas cell has. But as someone living in europe, i have certain problems getting my hands on a HP5065. There is virtually no surplus market here. And if there is anything sold in europe, the price is nearly that of a new device, sometimes even more (no, i'm neither joking nor exagerating). I cannot buy any of the fancy devices you have access to in the US. Buying a Cs beam, as a few of you have, is a dream that will not come true for me, unless i win in the lottery. But building my own Rb standard using laser diodes is feasible. I still lack a lot of knowledge and understanding how to do that, but this group has been very helpfull in filling my gaps, when asking the right questions. And if you don't mind, i would like to keep asking those questions. Attila Kinali -- The people on 4chan are like brilliant psychologists who also happen to be insane and gross. -- unknown ___ 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] HP5065B !!!
Attilla No one should or will discourage you from developing a laser pumped Rb. Bruce posted the following link. It addresses some of the issues and for me looking at lamp Rb's is most helpful. http://tf.boulder.nist.gov/general/pdf/1219.pdf Bert Kehren In a message dated 4/30/2013 4:51:57 P.M. Eastern Daylight Time, att...@kinali.ch writes: On Mon, 29 Apr 2013 17:19:05 -0400 (EDT) ewkeh...@aol.com wrote: I am still sitting here trying to figure out the purpose of posting the article on laser diode pumping of the Rb. One look at the data and it is clear that Corby’s work far surpasses the data shown in the paper. All it does is distract from Corb’s accomplishments. Sorry i didnt mean to do that. I am very gratefull at the work Corby has done and the new insights on what error sources a Rb gas cell has. But as someone living in europe, i have certain problems getting my hands on a HP5065. There is virtually no surplus market here. And if there is anything sold in europe, the price is nearly that of a new device, sometimes even more (no, i'm neither joking nor exagerating). I cannot buy any of the fancy devices you have access to in the US. Buying a Cs beam, as a few of you have, is a dream that will not come true for me, unless i win in the lottery. But building my own Rb standard using laser diodes is feasible. I still lack a lot of knowledge and understanding how to do that, but this group has been very helpfull in filling my gaps, when asking the right questions. And if you don't mind, i would like to keep asking those questions. Attila Kinali -- The people on 4chan are like brilliant psychologists who also happen to be insane and gross. -- unknown ___ 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] HP5065B !!!
Am I missing something? What actual modifications were done and how? Jim On 1 May 2013 07:30, ewkeh...@aol.com wrote: Attilla No one should or will discourage you from developing a laser pumped Rb. Bruce posted the following link. It addresses some of the issues and for me looking at lamp Rb's is most helpful. http://tf.boulder.nist.gov/general/pdf/1219.pdf Bert Kehren In a message dated 4/30/2013 4:51:57 P.M. Eastern Daylight Time, att...@kinali.ch writes: On Mon, 29 Apr 2013 17:19:05 -0400 (EDT) ewkeh...@aol.com wrote: I am still sitting here trying to figure out the purpose of posting the article on laser diode pumping of the Rb. One look at the data and it is clear that Corby’s work far surpasses the data shown in the paper. All it does is distract from Corb’s accomplishments. Sorry i didnt mean to do that. I am very gratefull at the work Corby has done and the new insights on what error sources a Rb gas cell has. But as someone living in europe, i have certain problems getting my hands on a HP5065. There is virtually no surplus market here. And if there is anything sold in europe, the price is nearly that of a new device, sometimes even more (no, i'm neither joking nor exagerating). I cannot buy any of the fancy devices you have access to in the US. Buying a Cs beam, as a few of you have, is a dream that will not come true for me, unless i win in the lottery. But building my own Rb standard using laser diodes is feasible. I still lack a lot of knowledge and understanding how to do that, but this group has been very helpfull in filling my gaps, when asking the right questions. And if you don't mind, i would like to keep asking those questions. Attila Kinali -- The people on 4chan are like brilliant psychologists who also happen to be insane and gross. -- unknown ___ 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] HP5065B !!!
I am still sitting here trying to figure out the purpose of posting the article on laser diode pumping of the Rb. One look at the data and it is clear that Corby’s work far surpasses the data shown in the paper. All it does is distract from Corb’s accomplishments. Lets be clear, Corby has opened the door of H Maser performance for those that have a HP 5065A. Not all work is done but a giant step has been accomplished, the challenge now is to continue the work. In simple terms it gets down to keep the A/V slope from turning upward. Work is going on off list to address some of the issues and maybe some one is willing to contribute. But what the list at a whole can do is contribute data as to HP 5065A performance. There are quite a few 5065A’s out there but very little data besides HP spec. To better tackle the flattening of the curve, aging, temperature sensitivity, barometric pressure sensitivity and even humidity sensitivity has to be understood. It is unrealistic to get past 1 E-13 unless this is understood and compensated for. Also some of these parameters will vary from unit to unit and some degree of tailoring to a particular unit has to be considered in the design. Some tests have to be done by those members that have access to a Maser. Also Corby found out that units with older A3 modules did not get the performance boost but replacement of A3 did get the super performance. That confirms my suspicion that there is room for work on frequency generation. PRS 10 does a direct frequency generation. Somehow using the step recovery diode as a mixer obviously works but is it optimum, or is there a better way to generate the resonator frequency? What is key to get the best signal and S/N ratio? When previously mentioning aging control, concern was voiced as to getting in to the HP 5065A. Corby’s work gets to the hart of the unit, the RVFR, but Corby has gone four for four. Adding control will only move the two C field wires to the analog board and using 30 mA from the unit. Unit can easily restored to its original condition as far as frequency control is concerned. Obviously the RVFR is the big differentiator in the HP5065A and I know of no commercially available unit that even gets close but once the work is complete a look at a FRK may be in order, I doubt it will ever be as good, but there is room for a filter and the physics part is considerable larger than today’s units. Some other units may be using a filter but the physics package is so small that compromises had to be made and the goal was more cost than ultimate performance. It is up to the list to turn this in to a Maser like performance with out mortgaging your home. Bert Kehren ___ 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] HP5065B !!!
Since performance improves as the bandwidth of the lamp spectrum decreases its not unreasonble to suggest that a suitable laser source may improve performance further. The following paper (and theoretical considerations) indicate that your conclusions regarding the potential performance of a laser pumped rubidium standard are incorrect. http://tf.boulder.nist.gov/general/pdf/1219.pdf The addition of second harmonic traps tuned to the 2nd harmonic of the modulation frequency of the resonance interrogation signals should improve the performance considerably. Bruce ewkeh...@aol.com wrote: I am still sitting here trying to figure out the purpose of posting the article on laser diode pumping of the Rb. One look at the data and it is clear that Corby’s work far surpasses the data shown in the paper. All it does is distract from Corb’s accomplishments. Lets be clear, Corby has opened the door of H Maser performance for those that have a HP 5065A. Not all work is done but a giant step has been accomplished, the challenge now is to continue the work. In simple terms it gets down to keep the A/V slope from turning upward. Work is going on off list to address some of the issues and maybe some one is willing to contribute. But what the list at a whole can do is contribute data as to HP 5065A performance. There are quite a few 5065A’s out there but very little data besides HP spec. To better tackle the flattening of the curve, aging, temperature sensitivity, barometric pressure sensitivity and even humidity sensitivity has to be understood. It is unrealistic to get past 1 E-13 unless this is understood and compensated for. Also some of these parameters will vary from unit to unit and some degree of tailoring to a particular unit has to be considered in the design. Some tests have to be done by those members that have access to a Maser. Also Corby found out that units with older A3 modules did not get the performance boost but replacement of A3 did get the super performance. That confirms my suspicion that there is room for work on frequency generation. PRS 10 does a direct frequency generation. Somehow using the step recovery diode as a mixer obviously works but is it optimum, or is there a better way to generate the resonator frequency? What is key to get the best signal and S/N ratio? When previously mentioning aging control, concern was voiced as to getting in to the HP 5065A. Corby’s work gets to the hart of the unit, the RVFR, but Corby has gone four for four. Adding control will only move the two C field wires to the analog board and using 30 mA from the unit. Unit can easily restored to its original condition as far as frequency control is concerned. Obviously the RVFR is the big differentiator in the HP5065A and I know of no commercially available unit that even gets close but once the work is complete a look at a FRK may be in order, I doubt it will ever be as good, but there is room for a filter and the physics part is considerable larger than today’s units. Some other units may be using a filter but the physics package is so small that compromises had to be made and the goal was more cost than ultimate performance. It is up to the list to turn this in to a Maser like performance with out mortgaging your home. Bert Kehren ___ 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] HP5065B !!!
I never came to that conclusion. There is enough work out there with results. My comment was to that particular paper that did not measure up to the work Corby has been doing. Still trying to figure out the purpose of the posting. Bert Kehren In a message dated 4/29/2013 6:34:24 P.M. Eastern Daylight Time, bruce.griffi...@xtra.co.nz writes: Since performance improves as the bandwidth of the lamp spectrum decreases its not unreasonble to suggest that a suitable laser source may improve performance further. The following paper (and theoretical considerations) indicate that your conclusions regarding the potential performance of a laser pumped rubidium standard are incorrect. http://tf.boulder.nist.gov/general/pdf/1219.pdf The addition of second harmonic traps tuned to the 2nd harmonic of the modulation frequency of the resonance interrogation signals should improve the performance considerably. Bruce ewkeh...@aol.com wrote: I am still sitting here trying to figure out the purpose of posting the article on laser diode pumping of the Rb. One look at the data and it is clear that Corby’s work far surpasses the data shown in the paper. All it does is distract from Corb’s accomplishments. Lets be clear, Corby has opened the door of H Maser performance for those that have a HP 5065A. Not all work is done but a giant step has been accomplished, the challenge now is to continue the work. In simple terms it gets down to keep the A/V slope from turning upward. Work is going on off list to address some of the issues and maybe some one is willing to contribute. But what the list at a whole can do is contribute data as to HP 5065A performance. There are quite a few 5065A’s out there but very little data besides HP spec. To better tackle the flattening of the curve, aging, temperature sensitivity, barometric pressure sensitivity and even humidity sensitivity has to be understood. It is unrealistic to get past 1 E-13 unless this is understood and compensated for. Also some of these parameters will vary from unit to unit and some degree of tailoring to a particular unit has to be considered in the design. Some tests have to be done by those members that have access to a Maser. Also Corby found out that units with older A3 modules did not get the performance boost but replacement of A3 did get the super performance. That confirms my suspicion that there is room for work on frequency generation. PRS 10 does a direct frequency generation. Somehow using the step recovery diode as a mixer obviously works but is it optimum, or is there a better way to generate the resonator frequency? What is key to get the best signal and S/N ratio? When previously mentioning aging control, concern was voiced as to getting in to the HP 5065A. Corby’s work gets to the hart of the unit, the RVFR, but Corby has gone four for four. Adding control will only move the two C field wires to the analog board and using 30 mA from the unit. Unit can easily restored to its original condition as far as frequency control is concerned. Obviously the RVFR is the big differentiator in the HP5065A and I know of no commercially available unit that even gets close but once the work is complete a look at a FRK may be in order, I doubt it will ever be as good, but there is room for a filter and the physics part is considerable larger than today’s units. Some other units may be using a filter but the physics package is so small that compromises had to be made and the goal was more cost than ultimate performance. It is up to the list to turn this in to a Maser like performance with out mortgaging your home. Bert Kehren ___ 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] HP5065B !!!
I have to agree that the subjects really drifted. I am very excited about what seems like a reasonable effort to improve the 5065. Since I have one all the more interest. So I want to hear about the reflectors and concentrators and how they were added and then how the system may have been retuned to leverage the change. Have I accidently gotten on to the wrong thread?? If so can some one please point me to the correct thread? Thanks Paul WB8TSL On Mon, Apr 29, 2013 at 6:30 PM, Bruce Griffiths bruce.griffi...@xtra.co.nz wrote: Since performance improves as the bandwidth of the lamp spectrum decreases its not unreasonble to suggest that a suitable laser source may improve performance further. The following paper (and theoretical considerations) indicate that your conclusions regarding the potential performance of a laser pumped rubidium standard are incorrect. http://tf.boulder.nist.gov/**general/pdf/1219.pdfhttp://tf.boulder.nist.gov/general/pdf/1219.pdf The addition of second harmonic traps tuned to the 2nd harmonic of the modulation frequency of the resonance interrogation signals should improve the performance considerably. Bruce ewkeh...@aol.com wrote: I am still sitting here trying to figure out the purpose of posting the article on laser diode pumping of the Rb. One look at the data and it is clear that Corby’s work far surpasses the data shown in the paper. All it does is distract from Corb’s accomplishments. Lets be clear, Corby has opened the door of H Maser performance for those that have a HP 5065A. Not all work is done but a giant step has been accomplished, the challenge now is to continue the work. In simple terms it gets down to keep the A/V slope from turning upward. Work is going on off list to address some of the issues and maybe some one is willing to contribute. But what the list at a whole can do is contribute data as to HP 5065A performance. There are quite a few 5065A’s out there but very little data besides HP spec. To better tackle the flattening of the curve, aging, temperature sensitivity, barometric pressure sensitivity and even humidity sensitivity has to be understood. It is unrealistic to get past 1 E-13 unless this is understood and compensated for. Also some of these parameters will vary from unit to unit and some degree of tailoring to a particular unit has to be considered in the design. Some tests have to be done by those members that have access to a Maser. Also Corby found out that units with older A3 modules did not get the performance boost but replacement of A3 did get the super performance. That confirms my suspicion that there is room for work on frequency generation. PRS 10 does a direct frequency generation. Somehow using the step recovery diode as a mixer obviously works but is it optimum, or is there a better way to generate the resonator frequency? What is key to get the best signal and S/N ratio? When previously mentioning aging control, concern was voiced as to getting in to the HP 5065A. Corby’s work gets to the hart of the unit, the RVFR, but Corby has gone four for four. Adding control will only move the two C field wires to the analog board and using 30 mA from the unit. Unit can easily restored to its original condition as far as frequency control is concerned. Obviously the RVFR is the big differentiator in the HP5065A and I know of no commercially available unit that even gets close but once the work is complete a look at a FRK may be in order, I doubt it will ever be as good, but there is room for a filter and the physics part is considerable larger than today’s units. Some other units may be using a filter but the physics package is so small that compromises had to be made and the goal was more cost than ultimate performance. It is up to the list to turn this in to a Maser like performance with out mortgaging your home. Bert Kehren __**_ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/** mailman/listinfo/time-nutshttps://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-nutshttps://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] HP5065B !!!
On 04/28/2013 07:50 AM, Bruce Griffiths wrote: Has anyone considered a laser pumped variant like: http://tf.nist.gov/general/pdf/1009.pdf Apart from the ECDL laser (can be assembled using readily availalble parts) it looks fairly straightforward. Bought a bunch of laser diodes of the cheap variant just to try it out. Never got around to try it. Cheers, Magnus ___ 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] HP5065B !!!
On Sun, 28 Apr 2013 17:50:06 +1200 Bruce Griffiths bruce.griffi...@xtra.co.nz wrote: Has anyone considered a laser pumped variant like: http://tf.nist.gov/general/pdf/1009.pdf Apart from the ECDL laser (can be assembled using readily availalble parts) it looks fairly straightforward. Considered, yes, tried, no. From what i've read sofar, this system has the problem of locking the laser wavelength onto the right absorbtion line. IIRC the linewidth of Rb in a vapor cell is a couple of 10kHz to a few 100kHz. Using an ECDL you get a laser linewidth of less than 1MHz easily, usally in the range of a few 100kHz and less. Ie. the laser would need to be kept on the absorption line with a stability of a couple of 100kHz at most. Using just a laser diode (without the external cavity) with its linewidth of 100MHz makes it actually a little bit easier to handle. But getting the laser to the right Rb absorption line and detecting whether it's off is still not solved. Most of the papers that i've read that do something similar use an additional vapor cell to determine the correct position of the laser. I'm quite sure that it could be done with a single vapor cell using some sophisticated control loop that steers both the 6.9Ghz signal and the laser wavelength, but i doubt it's easy. But then, i didn't have an in depth look at this. Attila Kinali -- The people on 4chan are like brilliant psychologists who also happen to be insane and gross. -- unknown ___ 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] HP5065B !!!
On 04/28/2013 02:01 PM, Attila Kinali wrote: On Sun, 28 Apr 2013 17:50:06 +1200 Bruce Griffithsbruce.griffi...@xtra.co.nz wrote: Has anyone considered a laser pumped variant like: http://tf.nist.gov/general/pdf/1009.pdf Apart from the ECDL laser (can be assembled using readily availalble parts) it looks fairly straightforward. Considered, yes, tried, no. From what i've read sofar, this system has the problem of locking the laser wavelength onto the right absorbtion line. IIRC the linewidth of Rb in a vapor cell is a couple of 10kHz to a few 100kHz. Using an ECDL you get a laser linewidth of less than 1MHz easily, usally in the range of a few 100kHz and less. Ie. the laser would need to be kept on the absorption line with a stability of a couple of 100kHz at most. Using just a laser diode (without the external cavity) with its linewidth of100MHz makes it actually a little bit easier to handle. But getting the laser to the right Rb absorption line and detecting whether it's off is still not solved. Most of the papers that i've read that do something similar use an additional vapor cell to determine the correct position of the laser. I'm quite sure that it could be done with a single vapor cell using some sophisticated control loop that steers both the 6.9Ghz signal and the laser wavelength, but i doubt it's easy. But then, i didn't have an in depth look at this. When being at NIST last summer, they had us tour the facility. One of them was not as much a show but a physical lab. We got to trim up and test laser-cooling of... rubidium vapour. It was about 10 of hardware on the table if I recall correctly, but nothing really advanced really. A secondary rubidium cell was used as a detector for the right rubidium features. Using that and tune two lasers with lock in amplifiers also having sweep features, it became fairly simple to do. More than half the table of equipment does not apply to a rubidium clock anyway, so the set up could be rationalized down considerably. We succeeded to laser-cool both the Rb-87 and Rb-85 :) Turned out that once you got about the right wavelengths and fairly balanced polarization, much other things like the magnetic field-strength was not very critical at all to achieve and maintain the effect. It was a fun lab to do, and I wish to learn more about steering laser wavelengths etc. I do far to little optical stuff. It is also interesting that our optically pumped rubidiums is in fact more closely related to modern atomic standards than traditional caesium beams. The fountains is really a cross of them both to some degree. Cheers, Magnus ___ 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] HP5065B !!!
On Sun, 28 Apr 2013 14:36:16 +0200 Magnus Danielson mag...@rubidium.dyndns.org wrote: On 04/28/2013 02:01 PM, Attila Kinali wrote: When being at NIST last summer, they had us tour the facility. One of them was not as much a show but a physical lab. We got to trim up and test laser-cooling of... rubidium vapour. It was about 10 of hardware on the table if I recall correctly, but nothing really advanced really. A secondary rubidium cell was used as a detector for the right rubidium features. Using that and tune two lasers with lock in amplifiers also having sweep features, it became fairly simple to do. More than half the table of equipment does not apply to a rubidium clock anyway, so the set up could be rationalized down considerably. Yes, it seems like it is fairly easy. At least [3] and [4] give that impression. We succeeded to laser-cool both the Rb-87 and Rb-85 :) Turned out that once you got about the right wavelengths and fairly balanced polarization, much other things like the magnetic field-strength was not very critical at all to achieve and maintain the effect. Yes, the magnetic field is there to provide an axis and orientation for the atoms. As for polarisation, AFAIK most of the MOT experiments use circular polarisation, to have an equal strength in all polarisation directions (but i can be mistaken). It was a fun lab to do, and I wish to learn more about steering laser wavelengths etc. I do far to little optical stuff. Then [1] and [2] will be of interest to you :-) It is also interesting that our optically pumped rubidiums is in fact more closely related to modern atomic standards than traditional caesium beams. The fountains is really a cross of them both to some degree. I thought about this as well. The principle of all atomic clocks is to get some popuplation inversion which is then probed by a microwave signal. Cs Beams and H-Masers use a magnetic fields to separate the atoms with different spins and select the right ones to feed into the cavity, while Rb and all optical clocks use light the electrons and the higher probabilty that an electron will fall into the higher state than in the lower state. I'm not exactly sure what a Cs fountain does. But considering the lack of a state selection magnet, i guess they are pumped by the laser light as well. Attila Kinali [1] Using diode lasers for atomic physics, by Wieman and Hollberg, 1990 http://web.mit.edu/kimt/www/nice_readings/wieman-diode-lasers.pdf [2] A narrow-band tunablediode laser system with gratingfeedback, and a saturatedabsorptionspectrometerfor Cs and Rb, by MacAdam, et al, 1992 http://fisica.usach.cl/~iolivare/MacAdamSteinbachWieman92.pdf [3] Inexpensive laser cooling and trapping experiment for undergraduate laboratories, by Wieman, Flowers and Gilbert, 1994 http://ajp.aapt.org/resource/1/ajpias/v63/i4/p317_s1 [4] A simple laser cooling and trapping apparatus for undergraduate laboratories by Mellish and Wilson, 2002 http://ajp.aapt.org/resource/1/ajpias/v70/i9/p965_s1 -- The people on 4chan are like brilliant psychologists who also happen to be insane and gross. -- unknown ___ 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] HP5065B !!!
Attila Kinali wrote: On Sun, 28 Apr 2013 17:50:06 +1200 Bruce Griffithsbruce.griffi...@xtra.co.nz wrote: Has anyone considered a laser pumped variant like: http://tf.nist.gov/general/pdf/1009.pdf Apart from the ECDL laser (can be assembled using readily availalble parts) it looks fairly straightforward. Considered, yes, tried, no. From what i've read sofar, this system has the problem of locking the laser wavelength onto the right absorbtion line. IIRC the linewidth of Rb in a vapor cell is a couple of 10kHz to a few 100kHz. Using an ECDL you get a laser linewidth of less than 1MHz easily, usally in the range of a few 100kHz and less. Ie. the laser would need to be kept on the absorption line with a stability of a couple of 100kHz at most. Using just a laser diode (without the external cavity) with its linewidth of100MHz makes it actually a little bit easier to handle. But the pump laser is then too noisy to allow a low noise rubidium standard to be implemented. With a temperature stabilised ECDL locking the laser to the D1 or D2 rubidium absorption feature whilst simultaneously stabilising the laser beam power can easily be achieved. But getting the laser to the right Rb absorption line and detecting whether it's off is still not solved. Most of the papers that i've read that do something similar use an additional vapor cell to determine the correct position of the laser. I'm quite sure that it could be done with a single vapor cell using some sophisticated control loop that steers both the 6.9Ghz signal and the laser wavelength, but i doubt it's easy. But then, i didn't have an in depth look at this. Attila Kinali Bruce ___ 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] HP5065B !!!
On Mon, 29 Apr 2013 06:28:55 +1200 Bruce Griffiths bruce.griffi...@xtra.co.nz wrote: Attila Kinali wrote: Considered, yes, tried, no. From what i've read sofar, this system has the problem of locking the laser wavelength onto the right absorbtion line. IIRC the linewidth of Rb in a vapor cell is a couple of 10kHz to a few 100kHz. Using an ECDL you get a laser linewidth of less than 1MHz easily, usally in the range of a few 100kHz and less. Ie. the laser would need to be kept on the absorption line with a stability of a couple of 100kHz at most. Using just a laser diode (without the external cavity) with its linewidth of100MHz makes it actually a little bit easier to handle. But the pump laser is then too noisy to allow a low noise rubidium standard to be implemented. With a temperature stabilised ECDL locking the laser to the D1 or D2 rubidium absorption feature whilst simultaneously stabilising the laser beam power can easily be achieved. Yes, there would be a lot more noise and also multi-mode ringing. But the question is, how do you reliable lock a narrow laser line to the right absorption line? How would the control loop work to keep the laser there? I'm asking mostly out of interest, because i have no clue how this is done. Although i've read many papers on laser spectroscopy and how to acheive even better atomic clocks using lasers, none of those papers mentiones how to get the laser there where it should be and how to keep it there. Attila Kinali -- The people on 4chan are like brilliant psychologists who also happen to be insane and gross. -- unknown ___ 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] HP5065B !!!
Hi, Where are the details of the changes and how to do them? Jim On Saturday, 27 April 2013, John Miles wrote: Very nice bit of RD work on Corby's part. Mine is certainly working well after the modification, but I'm just blown away at the performance seen with Tom's unit. Another plot of the Super mod that's worth mentioning: http://www.ke5fx.com/5065A_vs_maser_mask.png Below 1000 seconds it has no trouble passing the spec limits for a passive H-maser! For contrast, teeypical LPRO-101 performance is shown in green, and the red trace is from the second-best commercial Rb standard I've seen (Symmetricom XPRO). -- john, KE5FX Miles Design LLC -Original Message- From: time-nuts-boun...@febo.com javascript:; [mailto:time-nuts-javascript:; boun...@febo.com javascript:;] On Behalf Of cdel...@juno.comjavascript:; Sent: Friday, April 26, 2013 8:24 AM To: time-nuts@febo.com javascript:; Subject: [time-nuts] HP5065B !!! OK, that was just to get your attention! What do you call a modified HP 5065A that can give you an Allan Deviation of 4X10-13 @ 1 Second and 6X10-14 @ 100 Second? I call it the SUPER HP 5065A. Any of these links will get you to the document describing it. Have a look and see what it's all about! Enjoy, Corby http://leapsecond.com/corby/Super-5065A-Project.pdf or http://leapsecond.com/corby/superproj10.docx or http://www.febo.com/pages/HP5065A_SUPER for ___ time-nuts mailing list -- time-nuts@febo.com javascript:; 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 javascript:; 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] HP5065B !!!
Very nice bit of RD work on Corby's part. Mine is certainly working well after the modification, but I'm just blown away at the performance seen with Tom's unit. Hi John, Yes, apparently some 5065A respond better than others to Corby's clever mod. It's clear why there is improvement; it's an interesting challenge/mystery to understand why some get more improvement than others. I double checked its performance with both a TSC 5110A/5120A and your TimePod to be sure it wasn't me. In general, some HP 5065A are better than others. OTOH, this is somewhat true for any frequency standard: from pendulum to quartz to rubidium to cesium to hydrogen. It drives time nuts crazy (and turns some of us into eBay gold diggers) but this has been the case from the first hand-made quartz oscillators in the 1920's to, well, the hand-made GPS Rubidium's, or the hand-made cesium fountains of today. Every clock is slightly different. You can be practical and live with it, or a fanatic and keep searching for a slightly better one or finding out why and putting effort into tweaking parameters, swapping components, or boards, etc. I know Corby has done an amazing job over the years with vintage cesium and rubidium standards. I hope to have him upgrade some of my 5065A too. Just to clarify -- the excellent plot that Corby posted was a modified 5065A that I tested *for* him, not one that I actually own. So it's not Tom's unit, but one that Tom enjoyed testing. Note the baseline was a PHM vs. AHM, just to show the noise floor of the measurement system(s) and reference(s). /tvb Another plot of the Super mod that's worth mentioning: http://www.ke5fx.com/5065A_vs_maser_mask.png Below 1000 seconds it has no trouble passing the spec limits for a passive H-maser! For contrast, teeypical LPRO-101 performance is shown in green, and the red trace is from the second-best commercial Rb standard I've seen (Symmetricom XPRO). -- john, KE5FX Miles Design LLC -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts- boun...@febo.com] On Behalf Of cdel...@juno.com Sent: Friday, April 26, 2013 8:24 AM To: time-nuts@febo.com Subject: [time-nuts] HP5065B !!! OK, that was just to get your attention! What do you call a modified HP 5065A that can give you an Allan Deviation of 4X10-13 @ 1 Second and 6X10-14 @ 100 Second? I call it the SUPER HP 5065A. Any of these links will get you to the document describing it. Have a look and see what it's all about! Enjoy, Corby http://leapsecond.com/corby/Super-5065A-Project.pdf or http://leapsecond.com/corby/superproj10.docx or http://www.febo.com/pages/HP5065A_SUPER for ___ 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] HP5065B !!!
Has anyone considered a laser pumped variant like: http://tf.nist.gov/general/pdf/1009.pdf Apart from the ECDL laser (can be assembled using readily availalble parts) it looks fairly straightforward. Bruce Tom Van Baak wrote: Very nice bit of RD work on Corby's part. Mine is certainly working well after the modification, but I'm just blown away at the performance seen with Tom's unit. Hi John, Yes, apparently some 5065A respond better than others to Corby's clever mod. It's clear why there is improvement; it's an interesting challenge/mystery to understand why some get more improvement than others. I double checked its performance with both a TSC 5110A/5120A and your TimePod to be sure it wasn't me. In general, some HP 5065A are better than others. OTOH, this is somewhat true for any frequency standard: from pendulum to quartz to rubidium to cesium to hydrogen. It drives time nuts crazy (and turns some of us into eBay gold diggers) but this has been the case from the first hand-made quartz oscillators in the 1920's to, well, the hand-made GPS Rubidium's, or the hand-made cesium fountains of today. Every clock is slightly different. You can be practical and live with it, or a fanatic and keep searching for a slightly better one or finding out why and putting effort into tweaking parameters, swapping components, or boards, etc. I know Corby has done an amazing job over the years with vintage cesium and rubidium standards. I hope to have him upgrade some of my 5065A too. Just to clarify -- the excellent plot that Corby posted was a modified 5065A that I tested *for* him, not one that I actually own. So it's not Tom's unit, but one that Tom enjoyed testing. Note the baseline was a PHM vs. AHM, just to show the noise floor of the measurement system(s) and reference(s). /tvb Another plot of the Super mod that's worth mentioning: http://www.ke5fx.com/5065A_vs_maser_mask.png Below 1000 seconds it has no trouble passing the spec limits for a passive H-maser! For contrast, teeypical LPRO-101 performance is shown in green, and the red trace is from the second-best commercial Rb standard I've seen (Symmetricom XPRO). -- john, KE5FX Miles Design LLC -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts- boun...@febo.com] On Behalf Of cdel...@juno.com Sent: Friday, April 26, 2013 8:24 AM To: time-nuts@febo.com Subject: [time-nuts] HP5065B !!! OK, that was just to get your attention! What do you call a modified HP 5065A that can give you an Allan Deviation of 4X10-13 @ 1 Second and 6X10-14 @ 100 Second? I call it the SUPER HP 5065A. Any of these links will get you to the document describing it. Have a look and see what it's all about! Enjoy, Corby http://leapsecond.com/corby/Super-5065A-Project.pdf or http://leapsecond.com/corby/superproj10.docx or http://www.febo.com/pages/HP5065A_SUPER for ___ 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] HP5065B !!!
Hi Corby: That's great. Is there a lens system in the 5065 that shapes the light output so that it's all on the photo detector like in the reference paper? Have Fun, Brooke Clarke http://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html cdel...@juno.com wrote: OK, that was just to get your attention! What do you call a modified HP 5065A that can give you an Allan Deviation of 4X10-13 @ 1 Second and 6X10-14 @ 100 Second? I call it the SUPER HP 5065A. Any of these links will get you to the document describing it. Have a look and see what it's all about! Enjoy, Corby http://leapsecond.com/corby/Super-5065A-Project.pdf or http://leapsecond.com/corby/superproj10.docx or http://www.febo.com/pages/HP5065A_SUPER for ___ 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] HP5065B !!!
Pretty cool Corby! I have wondered about the line broadening caused by all that extra light energy being pumped into the filter cells... Looks like you have found the answer. Kind of makes you wonder why nobody else has ever done the experiment? -Chuck Harris cdel...@juno.com wrote: OK, that was just to get your attention! What do you call a modified HP 5065A that can give you an Allan Deviation of 4X10-13 @ 1 Second and 6X10-14 @ 100 Second? I call it the SUPER HP 5065A. Any of these links will get you to the document describing it. Have a look and see what it's all about! Enjoy, Corby http://leapsecond.com/corby/Super-5065A-Project.pdf or http://leapsecond.com/corby/superproj10.docx or http://www.febo.com/pages/HP5065A_SUPER for ___ 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] HP5065B !!!
Hi Corby, On 04/26/2013 05:23 PM, cdel...@juno.com wrote: OK, that was just to get your attention! What do you call a modified HP 5065A that can give you an Allan Deviation of 4X10-13 @ 1 Second and 6X10-14 @ 100 Second? I call it the SUPER HP 5065A. Any of these links will get you to the document describing it. Have a look and see what it's all about! Nice to see progress report from you on this project. Would you care to detail a little more of what changes you have done, what filter you used etc. so that fellow time-nuts like me could duplicate the improvement? Cheers, Magnus ___ 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] HP5065B !!!
Very nice bit of RD work on Corby's part. Mine is certainly working well after the modification, but I'm just blown away at the performance seen with Tom's unit. Another plot of the Super mod that's worth mentioning: http://www.ke5fx.com/5065A_vs_maser_mask.png Below 1000 seconds it has no trouble passing the spec limits for a passive H-maser! For contrast, teeypical LPRO-101 performance is shown in green, and the red trace is from the second-best commercial Rb standard I've seen (Symmetricom XPRO). -- john, KE5FX Miles Design LLC -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts- boun...@febo.com] On Behalf Of cdel...@juno.com Sent: Friday, April 26, 2013 8:24 AM To: time-nuts@febo.com Subject: [time-nuts] HP5065B !!! OK, that was just to get your attention! What do you call a modified HP 5065A that can give you an Allan Deviation of 4X10-13 @ 1 Second and 6X10-14 @ 100 Second? I call it the SUPER HP 5065A. Any of these links will get you to the document describing it. Have a look and see what it's all about! Enjoy, Corby http://leapsecond.com/corby/Super-5065A-Project.pdf or http://leapsecond.com/corby/superproj10.docx or http://www.febo.com/pages/HP5065A_SUPER for ___ 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.
