Re: [time-nuts] Special connector for Symmetricom X72 rubidium standard
On Sun, 20 Aug 2017 16:22:18 + Mark Sims wrote: > It can also be used with the SA22.c once a board that breaks out the SA22 > connector pinouts to a 34 pin cable (8 pins are for the SA22.c +5V power/ > gnd) is built. Note the TO-220 LM7805 voltage regulator... Symmeticom does > not deign to tell use mere peons how much current that needs. That > regulator may need to be a switcher or need a heat sink. Isn't this the "max warm up power" in the "X71 Design Absolute Maximum Rating" table in the designer's refernence manual? Or am I missing something? It states that the X72 uses 17W max 10W for 25°C ambient. Which sounds about as much as I expect for an vapor cell standard. Though 3A on 5V (or 2A @25°C) is a bit tough. Attila Kinali -- You know, the very powerful and the very stupid have one thing in common. They don't alters their views to fit the facts, they alter the facts to fit the views, which can be uncomfortable if you happen to be one of the facts that needs altering. -- The Doctor ___ 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] Special connector for Symmetricom X72 rubidium standard
Here's a look at the first cut of the signal interface board for the X72. The board does not bring out the LEDs. You can pick those off the connector board. It can also be used with the SA22.c once a board that breaks out the SA22 connector pinouts to a 34 pin cable (8 pins are for the SA22.c +5V power/gnd) is built. Note the TO-220 LM7805 voltage regulator... Symmeticom does not deign to tell use mere peons how much current that needs. That regulator may need to be a switcher or need a heat sink. The BNC on the end of the board is configured to output the programmable ACMOS output, but with a cut and jumper can output the FXO output (the 60 MHz X72 oscillator output) gps4.pdf Description: gps4.pdf ___ 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] Atomic clocks and Wassenaar agreement
On 8/20/17 9:15 AM, Attila Kinali wrote: On Sun, 20 Aug 2017 11:28:17 + "Poul-Henning Kamp" wrote: As far as I can tell, there is no explicit mention of atomic clocks. There very much is: Oops... missed that one. Sorry about that. (I wonder how. I am sure I searched for "atomic") But the list of dual use electronics is long and broad. E.g. Section 3. A. 1. b. 10. covers basically all low noise frequency sources. Including just a simple low-noise XO. Does anyone have more specific knowledge? Knowledge ? No. Some Experience ? Yes. My condolences. I only had to deal with ITAR as a buyer once. That was enough for a lifetime. The people who wrote the list very much know why they put things onto it, and in the process of narrowly tailoring the restrictions often give more away than they probably should. Yes. I skimmed through some of the electronic restrictions. Given that a lot of SDR can be used in one of those ways listed, it's damn easy to "accidentally" build something that has export restrictions on it. [1] I've always wondered about that rule and I suspect it is a mistake. Knowing who is on this list, I imagine that the next revision will read the far more sensible: "Non-rubidium *or* having ..." Yes, singling out Rubidium is kind of weird. Any guesses as for why? I have some experience in this area - in the US it's the USML (United States Muntions List) that determines what is subject to controls under ITAR - that's run by the Department of State. Then there's the Controlled Commodities List which features in the EAR run by the Department of Commerce. The two groups have different objectives. ITAR tends to focus a lot on "knowledge" as well as "things" - EAR is more about "things" - A component might be export controlled, but the data sheet isn't. Also, there's a huge difference between "speculating" that something is so and "knowing" that something is so, in terms of design information or performance. If you're interested in building, say, a guidance system for a ICBM - performance in a UAV might be a good indication that it would work, but there's no substitute for test in a real missile. A few years ago, there was a big rewriting of the USML - to make it more specific in terms of capabilities, etc. rather than fuzzy - folks seeking export licenses were frustrated by the previous more generic language (often including the phrase "designed for military purposes" or similar). For spacecraft, it got a lot more liberal - before "if it goes into space, it's ITAR" was the basic rule - afterwards, it's more about "does it tell someone how to make it, design it, etc." and a lot more things fell into more of a dual use (EAR is more about dual use) bucket - just because you're using 6-32 machine screws or 100MHz OCXOs on your spacecraft doesn't make ALL 6-32 screws or the same OCXO in other uses export controlled. This was a godsend for us cobbling together breadboards for things that might someday go into space in a different form - before, if the work was funded by a "space technology development" sort of bucket, the evaluators would tend to say: yeah, that's export controlled, because the "design intent" is for an eventual space application. That made it hard to publish papers and reports openly as well as other tedious administrative aspects - you can't put export controlled information just anywhere or transmit it any old way, etc. That process, of course, gets input from both industry and government, and is not perfect. But if you are a maker of a specific widget, you could weigh in on the rule making process and explain why YOUR particular widget's technology should or should not be controlled. "should not" if you want to sell it overseas; "should" if you want to avoid competition. And then, there's a sort of continuing revision process - as each new license application (or commodity jurisdiction (CJ) request) makes its way through the system, that folds back to the actual rules or, more importantly, their interpretation. ALso as "work-arounds" for technology become well known, the rules gradually change. A good example is things like selective availability and code-less 2 frequency GPS. There's also well known hacks - a mfr might claims that their parts are rad tolerant up to a particular level, even though they're made on a process which is well known to be much harder. To claim that they're hard to a higher level would make them subject to ITAR instead of EAR, for instance. Like all regulatory matters, the wheels grind slow and exceedingly fine. MUCH slower than the advance of technology (nothing has really changed since you couldn't export pinball machines which had 68000 microprocessors) and that's something you live with. And then, there's also just plain old typographical screwups - I'm sure there are rules where it should be AND instead of OR, or someone wrote a descrip
Re: [time-nuts] Atomic clocks and Wassenaar agreement
In message <20170820181537.a7a834e32b848ea3f63d3...@kinali.ch>, Attila Kinali writes: >On Sun, 20 Aug 2017 11:28:17 + >> [1] I've always wondered about that rule and I suspect it is a >> mistake. Knowing who is on this list, I imagine that the next >> revision will read the far more sensible: "Non-rubidium *or* >> having ..." > >Yes, singling out Rubidium is kind of weird. I see that rule as a way to carve out telco-class rubidiums, and that's why I think "or" would make much more sense than "and". -- 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] Atomic clocks and Wassenaar agreement
On Sun, 20 Aug 2017 11:28:17 + "Poul-Henning Kamp" wrote: > > > >As far as I can tell, there is no explicit mention of atomic > >clocks. > > There very much is: Oops... missed that one. Sorry about that. (I wonder how. I am sure I searched for "atomic") > >But the list of dual use electronics is long and broad. > >E.g. Section 3. A. 1. b. 10. covers basically all low noise > >frequency sources. Including just a simple low-noise XO. > >Does anyone have more specific knowledge? > > Knowledge ? No. Some Experience ? Yes. My condolences. I only had to deal with ITAR as a buyer once. That was enough for a lifetime. > The people who wrote the list very much know why they put things > onto it, and in the process of narrowly tailoring the restrictions > often give more away than they probably should. Yes. I skimmed through some of the electronic restrictions. Given that a lot of SDR can be used in one of those ways listed, it's damn easy to "accidentally" build something that has export restrictions on it. > [1] I've always wondered about that rule and I suspect it is a > mistake. Knowing who is on this list, I imagine that the next > revision will read the far more sensible: "Non-rubidium *or* > having ..." Yes, singling out Rubidium is kind of weird. Any guesses as for why? Attila Kinali -- You know, the very powerful and the very stupid have one thing in common. They don't alters their views to fit the facts, they alter the facts to fit the views, which can be uncomfortable if you happen to be one of the facts that needs altering. -- The Doctor ___ 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] Tsunami detection via GPS
Some here may find this of interest. http://www2.unb.ca/gge/Resources/gpsworld.february08.pdf Jim Palfreyman ___ 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] Atomic clocks and Wassenaar agreement
In message <20170820120742.c48c69758cc9fa4856ab0...@kinali.ch>, Attila Kinali writes: >On Sun, 20 Aug 2017 08:50:59 + >"Poul-Henning Kamp" wrote: > >> >Bob your right its interesting that the sales locations are in China and >> >India. Perhaps a larger opportunity for a RB reference today. >> >> Could be because hydrogen masers are dual-use under the Waasenaar >> Arrangement ? > >As far as I can tell, there is no explicit mention of atomic >clocks. There very much is: 3. A. 2. g. Atomic frequency standards being any of the following: 1. "Space-qualified"; 2. Non-rubidium and having a long-term stability less (better) than 1 x 10 -11 /month; or 3. Non-"space-qualified" and having all of the following: a. Being a rubidium standard; b. Long-term stability less (better) than 1 x 10 -11 /month; and c. Total power consumption of less than 1 Watt; The product in question drives directly through the loophole in point 2[1] >But the list of dual use electronics is long and broad. >E.g. Section 3. A. 1. b. 10. covers basically all low noise >frequency sources. Including just a simple low-noise XO. >Does anyone have more specific knowledge? Knowledge ? No. Some Experience ? Yes. The people who wrote the list very much know why they put things onto it, and in the process of narrowly tailoring the restrictions often give more away than they probably should. Depending on your hobbies, you can get some pretty interesting project ideas by reading the list[2]. (3.A.3 anyone ? or how about 9.B.6 ?) The civil servants who administer the lists in the foreign ministries are seldom rocket engineers and will usually administer the list strictly to the letter, rather than talk to one. Poul-Henning [1] I've always wondered about that rule and I suspect it is a mistake. Knowing who is on this list, I imagine that the next revision will read the far more sensible: "Non-rubidium *or* having ..." [2] http://www.wassenaar.org/wp-content/uploads/2016/12/List-of-Dual-Use-Goods-and-Technologies-and-Munitions-List-Corr.pdf -- 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] (no subject)
On 08/20/2017 10:50 AM, Poul-Henning Kamp wrote: In message , paul swed writes: Bob your right its interesting that the sales locations are in China and India. Perhaps a larger opportunity for a RB reference today. Could be because hydrogen masers are dual-use under the Waasenaar Arrangement ? No, hydrogen masers seems to be without that restriction as far as I know. 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] MuQuans MuClock
On Sat, 19 Aug 2017 16:46:29 -0400 paul swed wrote: > On Sat, Aug 19, 2017 at 3:46 PM, Bob kb8tq wrote: > > > On Aug 19, 2017, at 3:04 PM, Ole Petter Ronningen > > > I just stumbled across this: > > > https://www.muquans.com/index.php/products/mclock > > > > > > A commercially available cold atom rubidium clock! My apologies if this > > has > > > already been reported on the list. They presented their clock at EFTF/IFCS a month ago. They are still characterizing it (i.e. they put one up at SYRTE and measure what it's doing), but sofar the results look quite good. The paper will be put online in a couple of weeks/months on the EFTF homepage for everyone to read. I will refrain from recounting what I have seen, as I forgot too many of the details and might be more wrong than right. Sorry about that. > It hasn't been discussed before that I can recall. > But its a cold RB clock and though it stable its still a secondary > reference. Err.. no. It is a primary standard. The difference between a primary and a secondary standard is, that the primary has a guaranteed accuracy without calibration, while the secondary standard is "just" stable, but can be off a little bit. These MuClocks do not need calibartion at all, as they are interogating (almost) completely undisturbed atoms in vacuum, in free fall. But they use a secondary _realisation_ of the second as defined by the BIPM. Attila Kinali -- You know, the very powerful and the very stupid have one thing in common. They don't alters their views to fit the facts, they alter the facts to fit the views, which can be uncomfortable if you happen to be one of the facts that needs altering. -- The Doctor ___ 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] Atomic clocks and Wassenaar agreement
On Sun, 20 Aug 2017 08:50:59 + "Poul-Henning Kamp" wrote: > >Bob your right its interesting that the sales locations are in China and > >India. Perhaps a larger opportunity for a RB reference today. > > Could be because hydrogen masers are dual-use under the Waasenaar Arrangement > ? As far as I can tell, there is no explicit mention of atomic clocks. But the list of dual use electronics is long and broad. E.g. Section 3. A. 1. b. 10. covers basically all low noise frequency sources. Including just a simple low-noise XO. Does anyone have more specific knowledge? Attila Kinali -- You know, the very powerful and the very stupid have one thing in common. They don't alters their views to fit the facts, they alter the facts to fit the views, which can be uncomfortable if you happen to be one of the facts that needs altering. -- The Doctor ___ 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] (no subject)
Hi, On 08/19/2017 09:04 PM, Ole Petter Ronningen wrote: Hello I just stumbled across this: https://www.muquans.com/index.php/products/mclock A commercially available cold atom rubidium clock! My apologies if this has already been reported on the list. When we saw it in their booth during the EFTF-IFCS conference, they where reluctant to give a price. Seems it just getting out on the market. It is indeed an interesting option. I would like to know more about the details of operation, to see what capabilities it has to be built into an operations environment. It would also be interesting to see how the long-term looks as measured against TAI/UTC. 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] (no subject)
In message , paul swed writes: >Bob your right its interesting that the sales locations are in China and >India. Perhaps a larger opportunity for a RB reference today. Could be because hydrogen masers are dual-use under the Waasenaar Arrangement ? -- 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.