Re: [time-nuts] Introduction and info about a Lucent RFTG
Thank Rex and Paul for the replies From what I understand my RFTG has a GPSDO on oneside that has a crystal oven inside it, and a rubidium source on the other side. The rubidium source takes a signal from the GPSDO side and uses that for longer term stability. But If I am understanding you, Rex, that the rubidium is really not a gps locked oscillator and just a free running device. I will start tearing down the unit to figure out if I can make something more usable out of it. I will make sure to document it and post it somewhere on the web. I read somewhere on this group that there is a way to bypass the 15MHz generating circuit and use the existing hardware amplifier and distribution at 10MHz. I will also be looking into that as well. Rex, you are correct as there is no power supply inside and I have it hooked up to a open frame type switching supply externally. Paul - I will be setting up my GPS antenna shortly and trying to get it to lock to GPS for a more precise reference. Thanks all -Denver On Fri, Jul 4, 2014 at 9:38 PM, Rex r...@sonic.net wrote: Several years ago there were a number of these showing up pretty cheap on eBay, so I bought one. As I recall there were a couple of similar versions with some differences so take this recollection with a grain of salt. I did some tracing of the internals on the one I had and found the rubidium unit had no connection on the tuning pin (C-field) to the board circuits. So it was free running, only for backup in the system, and not GPS lockable. I don't remember there being any useful power supply in the box, so my advice would be to remove the LPRO rubidium and use it directly. (It does need heat sinking, so maybe some parts of the box mechanicals are useful.) In my opinion, working out how to use the supporting circuit board is not worth the effort, unless you really have a need for the 15 MHz they create. You should be able to find documentation for the internal module LPRO rubidiums on the web. I haven't looked today but KO4BB site probably has it. On 7/4/2014 1:47 PM, Denver wrote: Hi all, My name is Denver I am currently a freshman in college and the time bug has struck me. I recently acquired a Lucent RFTG on ebay to have a time standard for my lab(and yes already realize its 15MHz output but may be able to change that and or just use the 10MHz test point from the rubidium source). I made a power connector for it. Now that I have power applied and sort of verified its operation I am looking for more info about the connectors on the front panel. I have the KO4BB user documentation on it but it doesn't mention much about connectors and pinouts. I also have already searched the group for other mentions of the RFTG but all I am able to come up with is some of the newer models the -m and such. Maybe one of you could help point me in the right direction or give me some other ideas on how to get more use out of this unit. Thanks in advance -Denver ___ 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] Introduction and info about a Lucent RFTG
Hi Denver When you refer to one side or the other, do you have the complete RFTG unit with the two modules? I only have the internals of the Rubidium module so would hardly claim to be an expert on these, or on much else for that matter:-), but as I understand it from the documentation this is a reduntant system, in that either the GPSDO or the Rubidium module is active at any one time with the other in standby. In other words, there's no suggestion that the Rubidium module is locked to GPS, it is indeed free running, whilst the GPS module is used to discipline its own crystal oscillator. However, although the free running Rubidium module will need occasional adjustment, as opposed to the GPSDO wich shoudn't, a free running Rubidium reference is still not something to be sneezed at. Section 2.1 RFTG Functionality, in the documentation refers to this in more detail. There was a fair bit of discussion here at one time regarding these so I'm surprised you haven't found more in the archives. For example, another list member, Skip Withrow, produced an article in January 2013 detailing how to modify the RFTGm GPSDO to obtain a 10MHz output, which he suggests should also apply to the earlier versions and I've also seen information on the Rubidium modules. Because my Rubidium module arrived with just the two attached PCBs and no outer metalwork whatsoever it was easier for me anyway to just put the 15MHz generator board to one side and use the interface board only with its special D connector still attached to make the thing functional. If I'd had the complete unit, including metalwork, I would probably have approached it differently. On my unit at least the actual Rubidium module was an Efratom FRS and there's documentation available online for these should you wish to run it stand alone However, it would seem to me that without too much work, and utilising the existing metalwork, these two units between them could provide the basis for a 10MHz Rubidium Standard plus a separate 10MHz GPSDO, but turning them into a GPS disciplined Rubidium unit perhaps not quite so straightforward:-) Regards Nigel GM8PZR In a message dated 05/07/2014 07:38:44 GMT Daylight Time, denc...@gmail.com writes: Thank Rex and Paul for the replies From what I understand my RFTG has a GPSDO on oneside that has a crystal oven inside it, and a rubidium source on the other side. The rubidium source takes a signal from the GPSDO side and uses that for longer term stability. But If I am understanding you, Rex, that the rubidium is really not a gps locked oscillator and just a free running device. I will start tearing down the unit to figure out if I can make something more usable out of it. I will make sure to document it and post it somewhere on the web. I read somewhere on this group that there is a way to bypass the 15MHz generating circuit and use the existing hardware amplifier and distribution at 10MHz. I will also be looking into that as well. Rex, you are correct as there is no power supply inside and I have it hooked up to a open frame type switching supply externally. Paul - I will be setting up my GPS antenna shortly and trying to get it to lock to GPS for a more precise reference. Thanks all -Denver On Fri, Jul 4, 2014 at 9:38 PM, Rex r...@sonic.net wrote: Several years ago there were a number of these showing up pretty cheap on eBay, so I bought one. As I recall there were a couple of similar versions with some differences so take this recollection with a grain of salt. I did some tracing of the internals on the one I had and found the rubidium unit had no connection on the tuning pin (C-field) to the board circuits. So it was free running, only for backup in the system, and not GPS lockable. I don't remember there being any useful power supply in the box, so my advice would be to remove the LPRO rubidium and use it directly. (It does need heat sinking, so maybe some parts of the box mechanicals are useful.) In my opinion, working out how to use the supporting circuit board is not worth the effort, unless you really have a need for the 15 MHz they create. You should be able to find documentation for the internal module LPRO rubidiums on the web. I haven't looked today but KO4BB site probably has it. On 7/4/2014 1:47 PM, Denver wrote: Hi all, My name is Denver I am currently a freshman in college and the time bug has struck me. I recently acquired a Lucent RFTG on ebay to have a time standard for my lab(and yes already realize its 15MHz output but may be able to change that and or just use the 10MHz test point from the rubidium source). I made a power connector for it. Now that I have power applied and sort of verified its operation I am looking for more info about the connectors on the front panel. I have the KO4BB user documentation on it but it doesn't mention much about
[time-nuts] AOL problems again
I've just received another excessive bounce notification from the list, again I'm assuming because AOL has taken to rejecting any message that's forwarded such that it indicates it's still from AOL but isn't. Switching to digest and/or just reading the posts online is one fix but just wondering if anyone has found a way round this yet that still allows AOL users to receive individual messages without causing bounce problems? Regards Nigel GM8PZR ___ 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] Interesting frequency standard project
At 06:27 PM 7/4/2014, Hal Murray wrote: ... we have no requirement for that level of stability on the MW broadcasts. How stable are they? That varies greatly from station to station depending upon what transmitter they are running. Note also that compliance with the 20 Hz accuracy requirement varies so you would only want to use stations owned by companies with a good record of compliance with Part 73. Dale H. Cook, Contract Engineer, Roanoke/Lynchburg, VA http://plymouthcolony.net/starcityeng/index.html ___ 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] Welnavigate GS720 GPS Simulator
Hello, does anyone know more about the GPS Simulators from Welnavigate ? The company seems to longer exist for several years and not much information can be found, besides some manuals on archive.org. I am especially interested in the software which controls the hardware. From what I know so far the whole setup consists of a PC running the software (Windows NT or Windows 2000 based, some older ones used MS-DOS) which controls the hardware over a GPIB interface. There were various hardware variants, e.g. the GS 700, GS 720 or GS 1010, the main difference seems to be the number of simulated satellites. There is a patent from the company founder which describes the hardware. I would like to find out the GPIB commands which control the unit. From my understanding of the patent it should not be too hard to write software which provides the required control data (basically the 50 bps GPS data, code/phase offset and doppler shift) for each simulated satellite. Unfortunately the control logic of the GS 720 is completely FPGA based, even the GPIB interface. So there is no firmware on the GS 720 which would allow to reverse-engineer the GPIB commands. Without knowing the GPIB commands or having access to the original control software it is not possible to get the hardware do anything usefull (maybe besides using the high-precision oscillator inside the unit). Thanks for any hints and best regards, Dieter -- Dieter Spaar, Germany sp...@mirider.augusta.de ___ 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] Interesting frequency standard project
As stated AM stations in US must maintain 20 Hz accuracy. Most are well within that tolerance. I have measured many AM station's frequency as a function of my employment before retirement. Now comes HD radio. While the merits of HD AM radio are very much open to debate, one benefit is that the equipment for HD is GPS locked. If you can find an HD AM station you can probably bet they are very close to being on frequency. The ones I have measured have been right on and push the limits of my test equipment. Al, retired, mostly AKA k9si Date: Sat, 05 Jul 2014 06:20:36 -0400 From: Dale H. Cook starc...@plymouthcolony.net To: time-nuts@febo.com Subject: Re: [time-nuts] Interesting frequency standard project At 06:27 PM 7/4/2014, Hal Murray wrote: ... we have no requirement for that level of stability on the MW broadcasts. How stable are they? That varies greatly from station to station depending upon what transmitter they are running. Note also that compliance with the 20 Hz accuracy requirement varies so you would only want to use stations owned by companies with a good record of compliance with Part 73. Dale H. Cook, Contract Engineer, Roanoke/Lynchburg, VA http://plymouthcolony.net/starcityeng/index.html ___ 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] Interesting frequency standard project
In the seventies I did for some friends that had FCC First class licenses a counter that on the input had three J/K F/F's to subtract the IF from the LO. They modified receivers including running the IF in to saturation and they certified stations without going there.. I think measurements had to be done on a monthly basis. Since they where also HAM's they also used them on frequency contests. Bert Kehren In a message dated 7/5/2014 12:56:24 P.M. Eastern Daylight Time, alw.k...@gmail.com writes: As stated AM stations in US must maintain 20 Hz accuracy. Most are well within that tolerance. I have measured many AM station's frequency as a function of my employment before retirement. Now comes HD radio. While the merits of HD AM radio are very much open to debate, one benefit is that the equipment for HD is GPS locked. If you can find an HD AM station you can probably bet they are very close to being on frequency. The ones I have measured have been right on and push the limits of my test equipment. Al, retired, mostly AKA k9si Date: Sat, 05 Jul 2014 06:20:36 -0400 From: Dale H. Cook starc...@plymouthcolony.net To: time-nuts@febo.com Subject: Re: [time-nuts] Interesting frequency standard project At 06:27 PM 7/4/2014, Hal Murray wrote: ... we have no requirement for that level of stability on the MW broadcasts. How stable are they? That varies greatly from station to station depending upon what transmitter they are running. Note also that compliance with the 20 Hz accuracy requirement varies so you would only want to use stations owned by companies with a good record of compliance with Part 73. Dale H. Cook, Contract Engineer, Roanoke/Lynchburg, VA http://plymouthcolony.net/starcityeng/index.html ___ 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] Can anybody use a Fluke 207-1 VLF Rcvr/Comp or Trak Time Code units? Plus, Free Stuff Aug. 1/2
I am trying to make some space in a very over-crowded storage area here. I have a very nice Fluke VLF receiver comparator, s/n 130 c/w chart recorder, but never got a chance to try it out, because we have no antenna. if it's worth $50 to somebody, plus shipping, it can be yours. l also have a huge range of Trak (and others) time code generators, receivers, code converters, etc. email if any interest, set up your own cape canaveral launch control room! Not sure why I ever bought them, but they can certainly be yours. Also Sphere is having its annual Free Stuff event this coming friday and saturday (Aug 1+2), tons of free parts, test gear, Rf/microwave, electronic scrap, etc. Email for more details, or check the Tek and HP user groups on Yahoo. We have been doing this for over 10 years, people seem very pleased with what they get. yes, we are in Canada, but lots of people come up from washington and oregon, it's a great weekend excursion! We do take requests if we happen to have what you need. all the best, walter -- Walter Shawlee 2, President Sphere Research Corporation 3394 Sunnyside Rd., West Kelowna, BC V1Z 2V4 CANADA Phone: (250) 769-1834 walt...@sphere.bc.ca WS2: We're all in one boat, no matter how it looks to you ___ 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] Can anybody use a Fluke 207-1 VLF Rcvr/Comp or Trak Time Code units? Plus, Free Stuff Aug. 1/2
Hi, I'm looking for a Datum 9300 time code generator and / or manual... Thanks, Jim On Sat, Jul 5, 2014 at 2:44 PM, walter shawlee 2 walt...@sphere.bc.ca wrote: I am trying to make some space in a very over-crowded storage area here. I have a very nice Fluke VLF receiver comparator, s/n 130 c/w chart recorder, but never got a chance to try it out, because we have no antenna. if it's worth $50 to somebody, plus shipping, it can be yours. l also have a huge range of Trak (and others) time code generators, receivers, code converters, etc. email if any interest, set up your own cape canaveral launch control room! Not sure why I ever bought them, but they can certainly be yours. Also Sphere is having its annual Free Stuff event this coming friday and saturday (Aug 1+2), tons of free parts, test gear, Rf/microwave, electronic scrap, etc. Email for more details, or check the Tek and HP user groups on Yahoo. We have been doing this for over 10 years, people seem very pleased with what they get. yes, we are in Canada, but lots of people come up from washington and oregon, it's a great weekend excursion! We do take requests if we happen to have what you need. all the best, walter -- Walter Shawlee 2, President Sphere Research Corporation 3394 Sunnyside Rd., West Kelowna, BC V1Z 2V4 CANADA Phone: (250) 769-1834 walt...@sphere.bc.ca WS2: We're all in one boat, no matter how it looks to you ___ 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] Can anybody use a Fluke 207-1 VLF Rcvr/Comp or Trak Time Code units? Plus, Free Stuff Aug. 1/2
Hi Walter, Thanks for the posting here on Time-Nuts and the advanced warning of your annual event. I know those of us in the Pacific North West will consider the car trip. To fellow time-nuts -- Walter has been on the 'net for a very long time. See his superb web site (http://sphere.bc.ca/). He and I share a fascination with calculators, slide rules, and nixie tubes (both related to the historical pursuit of precise time frequency). I have no connection with his company (never even met him), but I can spot a 'nut from anywhere. /tvb - Original Message - From: walter shawlee 2 walt...@sphere.bc.ca To: time-nuts@febo.com Sent: Saturday, July 05, 2014 12:44 PM Subject: [time-nuts] Can anybody use a Fluke 207-1 VLF Rcvr/Comp or Trak Time Code units? Plus, Free Stuff Aug. 1/2 I am trying to make some space in a very over-crowded storage area here. I have a very nice Fluke VLF receiver comparator, s/n 130 c/w chart recorder, but never got a chance to try it out, because we have no antenna. if it's worth $50 to somebody, plus shipping, it can be yours. l also have a huge range of Trak (and others) time code generators, receivers, code converters, etc. email if any interest, set up your own cape canaveral launch control room! Not sure why I ever bought them, but they can certainly be yours. Also Sphere is having its annual Free Stuff event this coming friday and saturday (Aug 1+2), tons of free parts, test gear, Rf/microwave, electronic scrap, etc. Email for more details, or check the Tek and HP user groups on Yahoo. We have been doing this for over 10 years, people seem very pleased with what they get. yes, we are in Canada, but lots of people come up from washington and oregon, it's a great weekend excursion! We do take requests if we happen to have what you need. all the best, walter -- Walter Shawlee 2, President Sphere Research Corporation 3394 Sunnyside Rd., West Kelowna, BC V1Z 2V4 CANADA Phone: (250) 769-1834 walt...@sphere.bc.ca WS2: We're all in one boat, no matter how it looks to you ___ 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] Can anybody use a Fluke 207-1 VLF Rcvr/Comp or Trak Time Code units? Plus, Free Stuff Aug. 1/2
I'll second that about the nut part. The first time Tom and I had any dealings was when he bought some nixies on eBay that I desperately needed. Being a reasonable guy, he helped me out. BTW, I also have a very large calculator collection. Regards - Mike Mike B. Feher, EOZ Inc. 89 Arnold Blvd. Howell, NJ, 07731 732-886-5960 office 908-902-3831 cell -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Tom Van Baak Sent: Saturday, July 05, 2014 5:12 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Can anybody use a Fluke 207-1 VLF Rcvr/Comp or Trak Time Code units? Plus, Free Stuff Aug. 1/2 Hi Walter, Thanks for the posting here on Time-Nuts and the advanced warning of your annual event. I know those of us in the Pacific North West will consider the car trip. To fellow time-nuts -- Walter has been on the 'net for a very long time. See his superb web site (http://sphere.bc.ca/). He and I share a fascination with calculators, slide rules, and nixie tubes (both related to the historical pursuit of precise time frequency). I have no connection with his company (never even met him), but I can spot a 'nut from anywhere. /tvb - Original Message - From: walter shawlee 2 walt...@sphere.bc.ca To: time-nuts@febo.com Sent: Saturday, July 05, 2014 12:44 PM Subject: [time-nuts] Can anybody use a Fluke 207-1 VLF Rcvr/Comp or Trak Time Code units? Plus, Free Stuff Aug. 1/2 I am trying to make some space in a very over-crowded storage area here. I have a very nice Fluke VLF receiver comparator, s/n 130 c/w chart recorder, but never got a chance to try it out, because we have no antenna. if it's worth $50 to somebody, plus shipping, it can be yours. l also have a huge range of Trak (and others) time code generators, receivers, code converters, etc. email if any interest, set up your own cape canaveral launch control room! Not sure why I ever bought them, but they can certainly be yours. Also Sphere is having its annual Free Stuff event this coming friday and saturday (Aug 1+2), tons of free parts, test gear, Rf/microwave, electronic scrap, etc. Email for more details, or check the Tek and HP user groups on Yahoo. We have been doing this for over 10 years, people seem very pleased with what they get. yes, we are in Canada, but lots of people come up from washington and oregon, it's a great weekend excursion! We do take requests if we happen to have what you need. all the best, walter -- Walter Shawlee 2, President Sphere Research Corporation 3394 Sunnyside Rd., West Kelowna, BC V1Z 2V4 CANADA Phone: (250) 769-1834 walt...@sphere.bc.ca WS2: We're all in one boat, no matter how it looks to you ___ 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] Magnetic Resonance Spectrometer - redux
First, an apology. When I changed the topic on my original post, I thought that would be OK. Apparently that's still a thread-jacking. Sorry. I'm still interested in this Magnetic Resonance Spectrometer thing, though. On page 335 of the pdf linked below by Dave, there's an experiment with an MRS using water and the magnet from a magnetron available back then. Apparently the resonant frequency of hydrogen nuclei in water is 6.131325 MHz in that magnetic field. Did anyone ever pursue this with the idea of creating a frequency standard, or was the technology just too primitive at the time? Perhaps it's a repeatability problem from the magnetic flux standpoint? I can guess that temperature changes would cause enough of a flux strength change to cause a problem, but that's just a guess. Bob - AE6RV From: DaveH i...@blackmountainforge.com To: 'Discussion of precise time and frequency measurement' time-nuts@febo.com Sent: Saturday, June 28, 2014 1:09 PM Subject: Re: [time-nuts] Loran, GPS, Lightning, Timing A PDF of the 1960 book can be found here: http://www.sciencemadness.org/library/books/projects_for_the_amateur_scientist.pdf Dave ___ 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] Magnetic Resonance Spectrometer - redux
On Sat, Jul 5, 2014 at 10:47 PM, Bob Stewart b...@evoria.net wrote: First, an apology. When I changed the topic on my original post, I thought that would be OK. Apparently that's still a thread-jacking. Sorry. I'm still interested in this Magnetic Resonance Spectrometer thing, though. On page 335 of the pdf linked below by Dave, there's an experiment with an MRS using water and the magnet from a magnetron available back then. Apparently the resonant frequency of hydrogen nuclei in water is 6.131325 MHz in that magnetic field. Did anyone ever pursue this with the idea of creating a frequency standard, or was the technology just too primitive at the time? Perhaps it's a repeatability problem from the magnetic flux standpoint? I can guess that temperature changes would cause enough of a flux strength change to cause a problem, but that's just a guess. The substance recommended was Ferric Chloride as I recall. The characteristic was that the peak occurred quickly even with the rapid change in the B-field. The B-field was modulated at a 60Hz rate, enough to sweep the resonance across the oscillator's frequency. When the nuclei precessed at the frequency of the oscillator, the nuclei would absorb power from the oscillator, changing the plate-current of the oscillator. It was really just a fast grid-dip oscillator. (Well, plate dip oscillator.) Pretty simple. I keep threatening to build a new one that works much better and has a wider range, just to prove that I can. :-) And I can't think of any way of tying this to time-nuttery. If there are others still interested in this topic perhaps we can just communicate off-channel. -- Brian Lloyd Lloyd Aviation 706 Flightline Drive Spring Branch, TX 78070 br...@lloyd.com +1.916.877.5067 ___ 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] Magnetic Resonance Spectrometer - redux
Hi Bob: This is very similar to a proton precession magnetometer that measures the total magnetic field, not in vector components. There's a lot of amateur designs for these that you could use as the bases for a MRS. There is an article in the same publication for a tube type frequency standard that can be used to drive a line powered wall clock. The Magnatron magnets were probably Alinco, so if you upgraded to modern magnets it might be much more stable. http://en.wikipedia.org/wiki/Proton_magnetometer http://en.wikipedia.org/wiki/NMR Have Fun, Brooke Clarke http://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html http://www.prc68.com/I/DietNutrition.html Bob Stewart wrote: First, an apology. When I changed the topic on my original post, I thought that would be OK. Apparently that's still a thread-jacking. Sorry. I'm still interested in this Magnetic Resonance Spectrometer thing, though. On page 335 of the pdf linked below by Dave, there's an experiment with an MRS using water and the magnet from a magnetron available back then. Apparently the resonant frequency of hydrogen nuclei in water is 6.131325 MHz in that magnetic field. Did anyone ever pursue this with the idea of creating a frequency standard, or was the technology just too primitive at the time? Perhaps it's a repeatability problem from the magnetic flux standpoint? I can guess that temperature changes would cause enough of a flux strength change to cause a problem, but that's just a guess. Bob - AE6RV From: DaveH i...@blackmountainforge.com To: 'Discussion of precise time and frequency measurement' time-nuts@febo.com Sent: Saturday, June 28, 2014 1:09 PM Subject: Re: [time-nuts] Loran, GPS, Lightning, Timing A PDF of the 1960 book can be found here: http://www.sciencemadness.org/library/books/projects_for_the_amateur_scientist.pdf Dave ___ 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.
