Re: [time-nuts] Pendulums Atomic Clocks Gravity
Tom Van Baak said the following on 05/26/2007 10:51 PM: I don't know how many time nuts are interested in this but you need to realize that the first hint that the Earth itself was an unstable timekeeper came, not from quartz or atomic oscillators, but from these astronomical pendulum clocks. This is another chance to plug one of my favorite books, Tuxedo Park by Jennet Conant (ISBN 978-0684872889). It's the story of Alfred Loomis, an amateur physicist of extreme talent, who was also a Wall Street operator on the highest levels. He made himself a large fortune in the 20s, and was clever enough to sell out just before the great crash. He was one of the initial forces behind US scientific mobilization before WW2, and some of the original radar research was done at his mansion/laboratory in Tuxedo Park, NY. The time-nuts link is that he was interested in precise timekeeping. On a trip to London, he stopped in to Shortt's shop and ordered three of his clocks, paying up-front for them. This was at a time when Shortt had sold maybe half a dozen! He put the three clocks on separate pedestals solidly connected to the bedrock below his home. They were accurate enough that he was able to observe their gravitational interaction -- he had to arrange them so the pendulums swung at 120 degree angles to each other in order to avoid what we would call injection locking! He used the clocks to measure earth's rotation among other experiments. He also had early quartz oscillators and had a dedicated phone line to Bell Labs where they sent him a 1kHz tone generated from their quartz standard for intercomparison. One of the anecdotes in the book is that Loomis would send QSL cards to the various national time/frequency broadcasters, carefully noting how much they were in error! John ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] FMT
Hi Connie, My life has been a little complicated lately, but it will settle eventually :-) I was surprised to be so close just by ear. 20m was hard because of QSB, but 40 and 80 were good, with strong and stable signals. I have Spectrum Lab installed on this new to me laptop, so next week should be better. I will use the HP 8657B instead of the HP 3586 (the lack of attenuator on the 3586 TG output makes it hard to adjust the level of the injection signal). Resolution drops to 1 Hz instead of 0.1 Hz, but with Spectrum Lab, that should be fine. Thanks for running this exercise. That is most interesting. I wish ARRL had such a good setup... 73, Didier KO4BB -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Connie Marshall Sent: Saturday, May 26, 2007 10:43 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] FMT Hi Didier, Good to hear from you. Sounds like you did fine considering how bad condx were that night. I will send out an email on the time and frequency. I think it will be Thursday night this week, but not sure yet. Thanks for participating and have a good weekend 73 Connie K5CM -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Didier Juges Sent: Saturday, May 26, 2007 8:11 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] FMT Well, I was too late sending my results, but I did manage to listen to the signals this past Wednesday. I did not have time to prepare anything but listening by ear on the FT-1000 and using the HP-3586A as a beat generator (free running off it's internal Ovenair precision OCXO), I managed to get within 0.4 Hz on 40 m and 0.2 Hz on 80m (good signals). I was off by 1.5 Hz on 20m, where the signal was very weak with QSB, and I did not hear anything on 17m. Thanks Connie, I will try to be better prepared next week (hooked to GPS and using Spectrum Lab). Didier KO4BB ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts -- No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.5.467 / Virus Database: 269.8.0/818 - Release Date: 5/25/2007 12:32 PM ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] HP E1938 oscillator
Hi Said, private international shipment and customs is not that problematic to my knowledge and experience, at least between the USA and Europe. On Sat, 26 May 2007 20:39:23 EDT, [EMAIL PROTECTED] wrote: Hello Rick, on the customs issue, you may have to check the items against the commerce control list (CCL Export Administration Regulation) especially section 3A002 I believe. Even (or especially!) if they are of $0 value prototypes. --- That is true for bigger and commercial transfers. Customs would appreciate to get everything done for them, but who as private person does know about this long code list? I found, for private transfers and small numbers of items, specially for not new things of low or no commercial interest, it is ok and sufficient to describe verbally but understandable. Just an example: used old (cannibalized) oscillator (clock), for (amateur) radio transmitter, unknown state, likely defective, present value USD 8.-- (or: none, scrap, but may evtl. look suspicious) For transmitters, antennas and their parts as used by amateurs no tax will be collected, just the VAT, which are now 19%, if money is paid for and the value is higher than about $ 25. (Tax is anyway lower In worst case customs may anyway question the declaration and the recipient may then be asked for some clarifications and to open the package, because the persons there are not always familiar with the special nomenclature. Concerning the remark to prototypes: Years after official product launch for the international market, do these not loose their initial high non-material value? ... High-tech items such as this super-high-tech oscillator cannot be exported into all countries w/o export license. You have to check the list, and then consider each country individually. Usually most western countries do not present an issue except maybe Israel. --- Isn't it painted a bit too black? Are there on the world's market not devices freely traded, equipped with such but fully qualified new oscillators? How do you define then primary standards as surplus? I would consider other things eg. some special USOs designed for harsh environment or modern precision GPS rx etc. as (more) critical Fedex for example will ask for a harmonized code from the CCL to be written on the transport paperwork, and will not export it without written declaration by you. The government can be extremely sensitive to this, that's why some companies like MiniCircuits require a declaration of conformance even when buying and shipping their parts in the US! --- Maybe true for key technology parts, which are very special and essential for certain very important products for some countries ... It is for example illegal to just sent schematics to China via email without export license... bye, Said from the follow-on mail of Said: Just mark them as such: Gift, value $1 then maybe just go to jail :) bye, Said --- sounds a bit too pessimistic, by the way Gift in german does mean poison which in fact I would not propose to ship ;-) But in fact, gift, value $1 would call me to check the contents... regards Arnold Tibus, DK2WT ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Pendulums Atomic Clocks Gravity
For the same reason that a satellite in free fall is still subject to gravitational forces, so do objects in Lagrange points. These points represent areas where the centrifugal forces compensate for gravity from two objects instead of one for a regular satellite. The only way to be free from gravitation is infinite distance from mass, until someone actually invents the famous gravitational shield :-) I hope it comes in spray form... Didier Neville Michie wrote: Look up Lagrangian points on Wikipedia. There are points of zero gravitational force, about our planet. What is more, these points are stationary with respect to Earth, so Doppler effects would be zero. As the distance from Sun to Earth to Moon varies through the year it follows that the distance from Earth of these points must vary on a small scale. These points are good for satelites as the orbit never decays. cheers, Neville Michie ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
[time-nuts] HP-5328A Manuals / Schematics
I'm wanting to work on the divider chain to incease the gate time from 10 seconds up to something much longer forr increased resolution. Are these on-line somewhere? Tom in St. Louis Choose the right car based on your needs. Check out Yahoo! Autos new Car Finder tool. http://autos.yahoo.com/carfinder/ ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Pendulums Atomic Clocks Gravity
Didier, gravitational forces, so do objects in Lagrange points. These points represent areas where the centrifugal forces compensate for gravity I am almost sure that this will again produce me a lot of trouble in answering a lot of people but the idea that there are centrifugal forces which compensate for gravity are one of the BIGGEST misconcepts that one may have in physics at all although it is quite common and you may find statements like that eben in (bad) physics textbooks. Centrifugal forces are so called fictitious forces which are only observed from within accelerated systems. Normal physics is done in inertial systems. In an inertial system consisting of earth and an satellite there are only TWO forces available: The gravity force by which earth attracts the satellite and the gravitational force by which the satellite attracts earth. They are of the same magnitude but of opposite direction. That is the reason why the sum of forces is zero for the closed system consisting of earth and satellite. There is no place for any other force like centrifugal or so because there is no counterforce available that would make the sum of forces zero i case a centrifugal force would exist. In case you like to discuss it a bit please go on but be prepared that I will to blow your arguments into little bits. A good idea to start with is to look after what Newton's first law is saying about the behaviour of a body for which all forces compensate each other. Is that what a satellite does??? 73 Ulrich, DF6JB -Ursprüngliche Nachricht- Von: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Im Auftrag von Didier Juges Gesendet: Sonntag, 27. Mai 2007 16:54 An: Discussion of precise time and frequency measurement Betreff: Re: [time-nuts] Pendulums Atomic Clocks Gravity For the same reason that a satellite in free fall is still subject to gravitational forces, so do objects in Lagrange points. These points represent areas where the centrifugal forces compensate for gravity from two objects instead of one for a regular satellite. The only way to be free from gravitation is infinite distance from mass, until someone actually invents the famous gravitational shield :-) I hope it comes in spray form... Didier Neville Michie wrote: Look up Lagrangian points on Wikipedia. There are points of zero gravitational force, about our planet. What is more, these points are stationary with respect to Earth, so Doppler effects would be zero. As the distance from Sun to Earth to Moon varies through the year it follows that the distance from Earth of these points must vary on a small scale. These points are good for satelites as the orbit never decays. cheers, Neville Michie ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi- bin/mailman/listinfo/time-nuts ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
[time-nuts] The first time nut?
My mention of Alfred Loomis prompted me to get the book out and I found this quote (p. 70 of the hardcover edition): Loomis would remain a time nut for the rest of his life, according to Luis Alvarez, who recalled that Loomis always wore two Accutrons -- one on his right wrist and one on his left wrist. He would check them every day against WWV (the standard frequency broadcasting station of the National Bureau of Standards), and if one was gaining a half second on the other, he would wear it on the outside of his wrist instead of the inside, so that gravity changed the rate of the tuning fork and the two watches tracked each other, and WWV, to within less than a second a day. I know that at least one of us (not me!) was photographed in his younger days wearing one watch on each wrist... John ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] The first time nut?
In message [EMAIL PROTECTED], John Ackermann N8UR writes: [...]and if one was gaining a half second on the other, he would wear it on the outside of his wrist instead of the inside, so that gravity changed the rate of the tuning fork [...] I'd expect that the author got this wrong, it would be the temperature change that did it. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 [EMAIL PROTECTED] | 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 https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] The first time nut?
No, that is correct. The Accutron has a predictable position error, gaining or loosing a couple of seconds a day depending on whether the tines of the fork are pointing up or down. (gravity effects!). They are calibrated depending on whether it is worn on the inside or outside of the wrist, or whether on the left or right arm. He was simply taking advantage of this phenomenon to make it gain or loose without having to reset it. (on the original 214's there was no hack mechanism to start and stop the movement without taking the battery out). When the watch is worn, it's temperature is maintained at very close to body temperature, in effect it's own oven. Daun -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Poul-Henning Kamp Sent: Sunday, May 27, 2007 2:42 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] The first time nut? In message [EMAIL PROTECTED], John Ackermann N8UR writes: [...]and if one was gaining a half second on the other, he would wear it on the outside of his wrist instead of the inside, so that gravity changed the rate of the tuning fork [...] I'd expect that the author got this wrong, it would be the temperature change that did it. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 [EMAIL PROTECTED] | 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 https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] The first time nut?
On Sun, 27 May 2007 18:42:17 +, Poul-Henning Kamp wrote: In message [EMAIL PROTECTED], John Ackermann N8UR writes: [...]and if one was gaining a half second on the other, he would wear it on the outside of his wrist instead of the inside, so that gravity changed the rate of the tuning fork [...] I'd expect that the author got this wrong, it would be the temperature change that did it. Nope, The author got it right. I have an Accutron 214. It runs fast six up and slow twelve up. Regards, Bill, NL7F -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 [EMAIL PROTECTED] | 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 https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts Bill Beam NL7F -- No virus found in this outgoing message. Checked by AVG. Version: 7.5.467 / Virus Database: 269.8.0/818 - Release Date: 5/25/2007 12:32 PM ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] The first time nut?
Tom - So, on an average, you each had one :). - Mike B. Feher, N4FS 89 Arnold Blvd. Howell, NJ, 07731 732-886-5960 -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Tom Van Baak Sent: Sunday, May 27, 2007 3:31 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] The first time nut? I know that at least one of us (not me!) was photographed in his younger days wearing one watch on each wrist... 25 years ago: Tom (2), Don (0), Glenn (1): http://www.leapsecond.com/images/1982-tvb-pyramids-top.jpg /tvb ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] HP E1938 oscillator
Hi Rick, If I'm not too late, I would also like one - or preferably two. I am in England, so PayPal would be easiest for me, as the bank charges quite a bit for Dollar cheques. However, if PayPal is not convenient for you, I will use whatever method you prefer. I have imported quite a lot of equipment from the USA with no problems. There is a tick-box marked Gift, and a description of used (or surplus) amateur radio equipment would seem fine. A $1 value also seems justifiable given that they are un-guaranteed prototypes. Being relatively lightweight and in a small box, I doubt customs will give them a second look. Regards, Peter Vince I still have dozens of surplus E1938A's if anyone wants one. They are in worked the last time it was turned on, but no guarantee of specs condition. I can't accept money for these units. Rick Karlquist N6RK E1938A circuit designer Due to the high level of interest, I may need to limit the oscillators to one per person. I will be getting the oscillators out of storage today and will try to make an accounting of oscillators vs requestors. I am suggesting an $8.95 donation for a flat rate Priority Mail box. I think it will fit into one of those boxes. Regarding non-USA requestors: I will need to look into the customs aspect of this. If anyone on the list can give me a tutorial on this it would be helpful. These are gifts if that matters for customs purposes. Also, they have essentially zero market value as discards. I am happy that I can give these a good home. I almost threw them away last month while cleaning up. Rick Karlquist ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] The first time nut?
Maybe Tom made a big time error of about 10 years, as it reminds me of myself in the early 70's. Now just a young 62. - Mike B. Feher, N4FS 89 Arnold Blvd. Howell, NJ, 07731 732-886-5960 -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Poul-Henning Kamp Sent: Sunday, May 27, 2007 4:01 PM To: Tom Van Baak; Discussion of precise time and frequency measurement Subject: Re: [time-nuts] The first time nut? In message [EMAIL PROTECTED], Tom Van Baak writes: I know that at least one of us (not me!) was photographed in his younger days wearing one watch on each wrist... 25 years ago: Tom (2), Don (0), Glenn (1): http://www.leapsecond.com/images/1982-tvb-pyramids-top.jpg Which 1970ies supergroup is this ? :-) -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 [EMAIL PROTECTED] | 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 https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] HP E1938 oscillator
In a message dated 5/27/2007 07:55:58 Pacific Daylight Time, [EMAIL PROTECTED] writes: Hi Said, private international shipment and customs is not that problematic to my knowledge and experience, at least between the USA and Europe. On Sat, 26 May 2007 20:39:23 EDT, [EMAIL PROTECTED] wrote: Hi guys, ok, so there are always two approaches: you can (try to) get away with stuff, or follow the law. As long as they don't check closely you may get away with it... There are 100's of thousands of lawyers in the US trying to make sense of it all. There is no clear answer such as well these are old, don't work anymore, I can get them for $1, thus there should be no problem in not declaring them according to the export control requirements. The CCL clearly talks about items such as space qualified oscillators, or stability better than 1E-011 etc. I am not trying to advise anyone if these units fall under the CCL or not - that's up to the exporter to determine. I don't know if these were ever space qualified for example (in which case it would deficiently be inadvisable not to declare them correctly). It could be as easy as finding the item categories on the CCL, finding out that Great Britain is not on the prohibited country list (most likely it won't be) - and entering the correct harmonized code into the export docs. Even an export novice can do this in about 15 - 20 minutes. In a job I had some time ago we were not even allowed to send any schematics or firmware outside of the country without export docs. They were very paranoid - because they got busted before! Does anyone remember the export of the PGP source code? They published a printed book and sent it to Europe because they were not allowed to export the soft version of the code! Then again will customs check? Probably not. But what if they do? bye, Said ** See what's free at http://www.aol.com. ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] The first time nut?
From: Poul-Henning Kamp [EMAIL PROTECTED] Subject: Re: [time-nuts] The first time nut? Date: Sun, 27 May 2007 20:01:28 + Message-ID: [EMAIL PROTECTED] In message [EMAIL PROTECTED], Tom Van Baak writes: I know that at least one of us (not me!) was photographed in his younger days wearing one watch on each wrist... 25 years ago: Tom (2), Don (0), Glenn (1): http://www.leapsecond.com/images/1982-tvb-pyramids-top.jpg Which 1970ies supergroup is this ? :-) Alan Parson Project? :) I think their Pyramid album was from 1981 or so. OK, I am just too lazy to walk over and check the album. What is a few years off among time-nuts anyway? :) Looks like Glenn's T-shirt says Yamaha, which would be logical. :) Cheers, Magnus ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Info on HP 10514A and 10534A mixers?
- Original Message - From: John Ackermann N8UR [EMAIL PROTECTED] To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Monday, May 28, 2007 8:32 AM Subject: [time-nuts] Info on HP 10514A and 10534A mixers? Anyone have a manual for either (or both) of these mixers? I picked up a couple in very nice shape at the Dayton Hamvention and am doing what may be a very interesting experiment that involves using them to downmix two synthesizers set to produce a difference frequency in the HF range, and then measure their phase noise via the difference frequency. In particular, I'm interested in the optimal input levels, the output frequency range, and to verify what the L, X, and R connector markings are. I'm assuming L is local oscillator, X is input, and R is output, but that's just a guess (for all I know, L could be left and R could be right!) Thanks, John Don't think I ever saw a manual for these although I did use quite a few. The 1969 catalog (hparchive have it for download) has 3 pages describing them starting page 264. DaveB, NZ ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Pendulums Atomic Clocks Gravity
On Sat, 26 May 2007 19:54:21 -0700, Tom Van Baak [EMAIL PROTECTED] wrote: Even fused silica is unstable (see attachment). Single crystal materials should be significantly better. Ageing Invar doesn't do much for its dimensional instability. Bruce Nice plot. Thanks Bruce. Where'd you find it? Someday I want to visit your library! You are just amazing. I don't know what most of those materials are, but looking at the plots, seems Super Invar and Zerodur tags both point to the same line. The line just above is unlabeled. I wonder which should be assigned to this line. ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] HP E1938 oscillator
On 5/27/07, [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: The CCL clearly talks about items such as space qualified oscillators, or stability better than 1E-011 etc. I am not trying to advise anyone if these You mean it the Commerce Control List (CCL) talks about space qualified _atomic_ frequency standards. -- http://www.access.gpo.gov/bis/ear/pdf/ccl3.pdf 3A002 ... g. Atomic frequency standards having any of the following: g.1. Long-term stability (aging) less (better) than 1 x 10^-11/month; or g.2. Being space qualified. Note: 3A002.g.1 does not control non-space qualified rubidium standards. So quartz oscillators do not fall under this category. Nevermind, that as far as I know all HP oscillators are not space-qualified. ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Info on HP 10514A and 10534A mixers?
On Sun, 27 May 2007 16:32:49 -0400, John Ackermann N8UR [EMAIL PROTECTED] wrote: Anyone have a manual for either (or both) of these mixers? I picked up a couple in very nice shape at the Dayton Hamvention and am doing what may be a very interesting experiment that involves using them to downmix two synthesizers set to produce a difference frequency in the HF range, and then measure their phase noise via the difference frequency. In particular, I'm interested in the optimal input levels, the output frequency range, and to verify what the L, X, and R connector markings are. I'm assuming L is local oscillator, X is input, and R is output, but that's just a guess (for all I know, L could be left and R could be right!) Thanks, John L X R is pretty normal marking for the mixer ports, but sometimes the X is labeled I. L = Local Oscillator R = RF X or I = mix or IF ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Pendulums Atomic Clocks Gravity
Ulrich, Just returned from Mannheim, where the gravitational force on my body increased by ten pounds, due to the fine food. A NASA film explains the motion of satellites in the following way: You have a cannon aimed at 45 degrees into the sky, for maximum altitude. You fire the cannon, but the projectile falls back to Earth. So you increase the amount of gunpowder (propellant) which causes the projectile to fall to the Earth farther away. You keep increasing the propellant, and finally the projectile falls around the Earth in a circular path. The interesting thing is that the mass of the projectile does not affect the height of the orbit. Only the circular velocity determines the orbital altitude. When an astronaut drops a bolt from an assembly, it does not change orbital altitude because its mass is much smaller than the space station's mass. Instead, it maintains the same altitude unless it was given some small change in velocity. Obviously, the mass and gravity are still present and F=Ma, for all practical purposes. What happens is that the acceleration 'a' goes to zero because it is countered by a rotational acceleration, defined by the square of the rotational velocity times the distance between the centers of gravity of the Earth and the satellite. Set the rotational acceleration equal to gravitational acceleration, and you have an equation that determines the distance as a function of rotational velocity and the (constant) gravitational force. The fact that some people call the rotational acceleration 'fictitious' does not alter the results of the equation. Sorry, I don't accept the idea that the Earth and the Moon repel each other with only gravitational forces. Regards, Bill Hawkins -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Ulrich Bangert Sent: Sunday, May 27, 2007 12:59 PM To: 'Discussion of precise time and frequency measurement' Subject: Re: [time-nuts] Pendulums Atomic Clocks Gravity Didier, gravitational forces, so do objects in Lagrange points. These points represent areas where the centrifugal forces compensate for gravity I am almost sure that this will again produce me a lot of trouble in answering a lot of people but the idea that there are centrifugal forces which compensate for gravity are one of the BIGGEST misconcepts that one may have in physics at all although it is quite common and you may find statements like that eben in (bad) physics textbooks. Centrifugal forces are so called fictitious forces which are only observed from within accelerated systems. Normal physics is done in inertial systems. In an inertial system consisting of earth and an satellite there are only TWO forces available: The gravity force by which earth attracts the satellite and the gravitational force by which the satellite attracts earth. They are of the same magnitude but of opposite direction. That is the reason why the sum of forces is zero for the closed system consisting of earth and satellite. There is no place for any other force like centrifugal or so because there is no counterforce available that would make the sum of forces zero i case a centrifugal force would exist. In case you like to discuss it a bit please go on but be prepared that I will to blow your arguments into little bits. A good idea to start with is to look after what Newton's first law is saying about the behaviour of a body for which all forces compensate each other. Is that what a satellite does??? 73 Ulrich, DF6JB ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Info on HP 10514A and 10534A mixers?
Rex said the following on 05/27/2007 05:12 PM: L X R is pretty normal marking for the mixer ports, but sometimes the X is labeled I. L = Local Oscillator R = RF X or I = mix or IF Thanks! John ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Info on HP 10514A and 10534A mixers?
Dave Brown said the following on 05/27/2007 05:02 PM: Don't think I ever saw a manual for these although I did use quite a few. The 1969 catalog (hparchive have it for download) has 3 pages describing them starting page 264. DaveB, NZ Thanks, Dave. That catalog has all the info you'd ever want. Boy, those old HP catalogs were more like a textbook than a sales tool! John ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Info on HP 10514A and 10534A mixers?
From: John Ackermann N8UR [EMAIL PROTECTED] Subject: Re: [time-nuts] Info on HP 10514A and 10534A mixers? Date: Sun, 27 May 2007 17:35:44 -0400 Message-ID: [EMAIL PROTECTED] John, Dave Brown said the following on 05/27/2007 05:02 PM: Don't think I ever saw a manual for these although I did use quite a few. The 1969 catalog (hparchive have it for download) has 3 pages describing them starting page 264. DaveB, NZ Thanks, Dave. That catalog has all the info you'd ever want. Boy, those old HP catalogs were more like a textbook than a sales tool! That IS a salestool. A good salestool. If only people would understand this. Cheers, Magnus ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Pendulums Atomic Clocks Gravity
Hello Ulrich, is it not important to bring into the game the satellite's velocity in relation to earth (on a tangential straight path deviated by gravitational acceleration)? 73, Arnold, DK2WT On Sun, 27 May 2007 19:59:22 +0200, Ulrich Bangert wrote: Didier, gravitational forces, so do objects in Lagrange points. These points represent areas where the centrifugal forces compensate for gravity I am almost sure that this will again produce me a lot of trouble in answering a lot of people but the idea that there are centrifugal forces which compensate for gravity are one of the BIGGEST misconcepts that one may have in physics at all although it is quite common and you may find statements like that eben in (bad) physics textbooks. Centrifugal forces are so called fictitious forces which are only observed from within accelerated systems. Normal physics is done in inertial systems. In an inertial system consisting of earth and an satellite there are only TWO forces available: The gravity force by which earth attracts the satellite and the gravitational force by which the satellite attracts earth. They are of the same magnitude but of opposite direction. That is the reason why the sum of forces is zero for the closed system consisting of earth and satellite. There is no place for any other force like centrifugal or so because there is no counterforce available that would make the sum of forces zero i case a centrifugal force would exist. In case you like to discuss it a bit please go on but be prepared that I will to blow your arguments into little bits. A good idea to start with is to look after what Newton's first law is saying about the behaviour of a body for which all forces compensate each other. Is that what a satellite does??? 73 Ulrich, DF6JB -Ursprüngliche Nachricht- Von: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Im Auftrag von Didier Juges Gesendet: Sonntag, 27. Mai 2007 16:54 An: Discussion of precise time and frequency measurement Betreff: Re: [time-nuts] Pendulums Atomic Clocks Gravity For the same reason that a satellite in free fall is still subject to gravitational forces, so do objects in Lagrange points. These points represent areas where the centrifugal forces compensate for gravity from two objects instead of one for a regular satellite. The only way to be free from gravitation is infinite distance from mass, until someone actually invents the famous gravitational shield :-) I hope it comes in spray form... Didier Neville Michie wrote: Look up Lagrangian points on Wikipedia. There are points of zero gravitational force, about our planet. What is more, these points are stationary with respect to Earth, so Doppler effects would be zero. As the distance from Sun to Earth to Moon varies through the year it follows that the distance from Earth of these points must vary on a small scale. These points are good for satelites as the orbit never decays. cheers, Neville Michie ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Pendulums Atomic Clocks Gravity
Rex wrote: On Sat, 26 May 2007 19:54:21 -0700, Tom Van Baak [EMAIL PROTECTED] wrote: Even fused silica is unstable (see attachment). Single crystal materials should be significantly better. Ageing Invar doesn't do much for its dimensional instability. Bruce Nice plot. Thanks Bruce. Where'd you find it? Someday I want to visit your library! You are just amazing. I don't know what most of those materials are, but looking at the plots, seems Super Invar and Zerodur tags both point to the same line. The line just above is unlabeled. I wonder which should be assigned to this line. ___ Rex Dont even think about super Invar. It was only this stable at a particular temperature. When measured at a different temperature it proved no more stable than invar. Bruce ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] HP E1938 oscillator
Said, I am sorry, I do not want to figth nor I want being involved in possible fights, nor do I give instructions to cheat, in contrary, I did try to help with my knowledge of european import laws and procedures for normal goods, shipped privatly. If necessary I can provide some documents concerned non commercial international shipments. I think that it is obvious for everybody, restricted items or confidential documents cannot be shipped this way. I was not aware of actual military or space-qualified and restricted items. Btw. I am familiar with such procedures, I designed and tested decades of years electronical systems and instrument-interfaces in international projects like Spacelab, ERS1, ERS2, ENVISAT etc. (worth up to ¬ 500E6) containing a big number of international hi-tech products... I wish to Rick a good and wise hand for the distribution of his electronic jewels, containing a big amount of spirit from a very successful design engineer. 73, Arnold, DK2WT On Sun, 27 May 2007 16:32:22 EDT, [EMAIL PROTECTED] wrote: In a message dated 5/27/2007 07:55:58 Pacific Daylight Time, [EMAIL PROTECTED] writes: Hi Said, private international shipment and customs is not that problematic to my knowledge and experience, at least between the USA and Europe. On Sat, 26 May 2007 20:39:23 EDT, [EMAIL PROTECTED] wrote: Hi guys, ok, so there are always two approaches: you can (try to) get away with stuff, or follow the law. As long as they don't check closely you may get away with it... There are 100's of thousands of lawyers in the US trying to make sense of it all. There is no clear answer such as well these are old, don't work anymore, I can get them for $1, thus there should be no problem in not declaring them according to the export control requirements. The CCL clearly talks about items such as space qualified oscillators, or stability better than 1E-011 etc. I am not trying to advise anyone if these units fall under the CCL or not - that's up to the exporter to determine. I don't know if these were ever space qualified for example (in which case it would deficiently be inadvisable not to declare them correctly). It could be as easy as finding the item categories on the CCL, finding out that Great Britain is not on the prohibited country list (most likely it won't be) - and entering the correct harmonized code into the export docs. Even an export novice can do this in about 15 - 20 minutes. In a job I had some time ago we were not even allowed to send any schematics or firmware outside of the country without export docs. They were very paranoid - because they got busted before! Does anyone remember the export of the PGP source code? They published a printed book and sent it to Europe because they were not allowed to export the soft version of the code! Then again will customs check? Probably not. But what if they do? bye, Said ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] HP E1938 oscillator
In a message dated 5/27/2007 15:25:24 Pacific Daylight Time, [EMAIL PROTECTED] writes: I think that it is obvious for everybody, restricted items or confidential documents cannot be shipped this way. Hi Arnold, you are probably right, it's probably not a big deal to send these items overseas. All that needs to be done by Rick is to check against the CCL and make a judgement call. We are talking about the US export controls here, the EU import regulations are a totally different beast. Rick did however ask for advice from the group, and I just stated what the law says :) And again, I worked for someone who got into trouble with exporting high-tech stuff so I am probably more conservative than other folks. Then again de-facto ways of doing things, and de-jure are two totally different things. Lastly, he is probably not going to send only one or two overseas, but a hole bunch so his exposure is higher. bye, Said ** See what's free at http://www.aol.com. ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] HP E1938 oscillator
In a message dated 5/27/2007 14:06:11 Pacific Daylight Time, [EMAIL PROTECTED] writes: On 5/27/07, [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: The CCL clearly talks about items such as space qualified oscillators, or stability better than 1E-011 etc. I am not trying to advise anyone if these You mean it the Commerce Control List (CCL) talks about space qualified _atomic_ frequency standards. Again, I am not qualified to make any recommendations about the CCL, or this product, and was not trying to do that. The list is very long, and get's updated from time to time. One has to check one's product against the entire list. The exporter has to do that, since they are ultimately responsible. I as an exporter would not follow anyone's interpretation of the CCL unless checking it thoroughly myself. You ask three experts (lawyers etc) and get three different opinions. My points were: A) the exporter has to check the entire CCL against their product. Maybe there are internal parts in the product that need to be declared?? Maybe the item is totally exempted. Who knows. This item strikes me as sensitive, since it is an Ultra High Stability Oscillator, and not just a 10MHz Microprocessor crystal. B) The exporter has to check the CCL against the country that is being exported to. If it is blacklisted, an export license is required. The exporter is liable, since he/she signs the paperwork against penalty of law. Most countries are probably no problem whatsoever, such as Western Europe, New Zealand etc. C) A harmonized code from the CCL is needed, even if it is an all clear code. Otherwise Fedex etc. will not ship. D) You can take the risk and not declare it correctly as has been suggested by some folks here. That's just like not paying taxes, you may get away with it most of the time. The one time they check will bite you. This is especially true here since the events of 2001. There is a saying in German: Dummheit schuetzt vor Strafe nicht loosely translated as Ignorance doesen't prevent penalty... bye, Said ** See what's free at http://www.aol.com. ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] HP E1938 oscillator
Said Part of the confusion probably stems from such gems as: Technical Notes: 1. A resolution of n bit corresponds to a quantization of 2n levels. Random snippet from Supplement No1 to Part 774. Bruce ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Pendulums Atomic Clocks Gravity
Ulrich, From NASA: http://map.gsfc.nasa.gov/m_mm/ob_techorbit1.html quote More precisely, the *Lagrange Points* mark positions where the gravitational pull of the two large masses precisely equals the centripetal force required to rotate with them. /quote I am in good company :-) (except that I used the term centrifugal instead of centripetal) Didier KO4BB Ulrich Bangert wrote: Didier, gravitational forces, so do objects in Lagrange points. These points represent areas where the centrifugal forces compensate for gravity I am almost sure that this will again produce me a lot of trouble in answering a lot of people but the idea that there are centrifugal forces which compensate for gravity are one of the BIGGEST misconcepts that one may have in physics at all although it is quite common and you may find statements like that eben in (bad) physics textbooks. Centrifugal forces are so called fictitious forces which are only observed from within accelerated systems. Normal physics is done in inertial systems. In an inertial system consisting of earth and an satellite there are only TWO forces available: The gravity force by which earth attracts the satellite and the gravitational force by which the satellite attracts earth. They are of the same magnitude but of opposite direction. That is the reason why the sum of forces is zero for the closed system consisting of earth and satellite. There is no place for any other force like centrifugal or so because there is no counterforce available that would make the sum of forces zero i case a centrifugal force would exist. In case you like to discuss it a bit please go on but be prepared that I will to blow your arguments into little bits. A good idea to start with is to look after what Newton's first law is saying about the behaviour of a body for which all forces compensate each other. Is that what a satellite does??? 73 Ulrich, DF6JB -Ursprüngliche Nachricht- Von: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Im Auftrag von Didier Juges Gesendet: Sonntag, 27. Mai 2007 16:54 An: Discussion of precise time and frequency measurement Betreff: Re: [time-nuts] Pendulums Atomic Clocks Gravity For the same reason that a satellite in free fall is still subject to gravitational forces, so do objects in Lagrange points. These points represent areas where the centrifugal forces compensate for gravity from two objects instead of one for a regular satellite. The only way to be free from gravitation is infinite distance from mass, until someone actually invents the famous gravitational shield :-) I hope it comes in spray form... Didier Neville Michie wrote: Look up Lagrangian points on Wikipedia. There are points of zero gravitational force, about our planet. What is more, these points are stationary with respect to Earth, so Doppler effects would be zero. As the distance from Sun to Earth to Moon varies through the year it follows that the distance from Earth of these points must vary on a small scale. These points are good for satelites as the orbit never decays. cheers, Neville Michie ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi- bin/mailman/listinfo/time-nuts ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] HP E1938 oscillator
In a message dated 5/27/2007 16:10:46 Pacific Daylight Time, [EMAIL PROTECTED] writes: Technical Notes: 1. A resolution of n bit corresponds to a quantization of 2n levels. Random snippet from Supplement No1 to Part 774. Bruce Hi Bruce, I have yet to figure it out too. That's why we have all these lawyers here in the US. What's even worse: if you give (well meant) advice, and the person get's into trouble, they can come after you :( But I think in spirit the export controls mean: anything that is of technical value, especially if it can be used militarily, needs to be under very close control of the government. Then again most Western Countries are free of most export restrictions. bye, Said ** See what's free at http://www.aol.com. ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] HP E1938 oscillator
[EMAIL PROTECTED] wrote: In a message dated 5/27/2007 16:10:46 Pacific Daylight Time, [EMAIL PROTECTED] writes: Technical Notes: 1. A resolution of n bit corresponds to a quantization of 2n levels. Random snippet from Supplement No1 to Part 774. Bruce Hi Bruce, I have yet to figure it out too. That's why we have all these lawyers here in the US. What's even worse: if you give (well meant) advice, and the person get's into trouble, they can come after you :( But I think in spirit the export controls mean: anything that is of technical value, especially if it can be used militarily, needs to be under very close control of the government. Then again most Western Countries are free of most export restrictions. bye, Said Said As far as I have been able to ascertain the list of export controlled items is virtually identical for most western countries and Russia. There are some slight variations (mainly additions) between countries. No doubt (for Russia at least) the country list classifications differ. I stumbled over the local NZ list of export controlled items, as usual purely by accident, when searching for something somewhat unrelated (External cavity diode lasers). As far as I can tell by perusing the complete CCL list (US version) neither the E1938A nor any of its component parts is a controlled item. It would take a creative interpretation by an incompetent lawyer to apply the section on Atomic frequency standards to the E1938A which is not by any stretch of the imagination an Atomic frequency standard. It is not capable of being space qualified without substantial redesign nor is it capable by design of achieving a drift of 1E-11 or less per month. Since the US has no jurisdiction here I can give well intentioned advice without worrying about prosecution (as long as I don't visit the US at least). Bruce ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
