Re: [time-nuts] Need some wisdom from the cesium beam tube gurus out there
Quite true, of course. I was only anticipating a quick-&-dirty temperature check... I should have realised that q-&-d isn't in a Time-Nut's vocabulary. :-) Mike On 11/11/2016 06:39, Bill Hawkins wrote: Well, they cancel if they're at the same temperature. Bill Hawkins -Original Message- From: Mike Millen Sent: Friday, November 11, 2016 12:28 AM It would work as well if you used a pair of regular copper wires to connect the meter to the thermocouple... The junctions created by all the new connections will cancel out. ___ 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] Need some wisdom from the cesium beam tube gurus out there
Well, they cancel if they're at the same temperature. Bill Hawkins -Original Message- From: Mike Millen Sent: Friday, November 11, 2016 12:28 AM It would work as well if you used a pair of regular copper wires to connect the meter to the thermocouple... The junctions created by all the new connections will cancel out. Mike ___ 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] Nutty time-nuttery with WWVB
There are some problems with the Internet of Things and security. For example, look up the Mirai botnet and the DDoS attack on DNS provider Dyn last month. To understand the situation better, read Bruce Schneier's "Secrets and Lies", available as a PDF. The book was written in 2000 when things were simpler and easier to understand, but it still applies. The man has a sense of humor. Schneier makes the point that it is difficult to test software functionality but impossible to test for security. Buffer overruns were a problem back when Morris wrote the first worm. They are still a problem because software vendors can write legal license agreements that say the vendor is not responsible for any failures caused by the software. Basically, you bought it on an "as-is" basis. So the software ships, bugs are discovered, and sometimes the vendor fixes the bugs, especially if they are made public. Vendors don't spend money doing things they don't have to do. IoT devices are made as cheaply as possible. They are made user friendly by not burdening the user with security configuration, so user names and passwords have well-known defaults. The device has no anti-virus application. The simple routers offer little protection, as they have their own issues with default keys to their configuration. Marketing departments have gotten very good at stampeding buyers for things of little value. So good that companies that make the control systems for the nation's manufacturing plants and utilities have embraced the Industrial IoT. That should have been the Industrial Distributed IoT (IDIoT). Previously, control systems had no connection to the Internet, and so there was no need for Internet Security concerns. Now there are many security services, so the IDIoT has created jobs, as well as sales of routers. The air gap and the data diode have been discredited since Stuxnet, which was spread by strewing the parking lot with USB drives. Schneier emphasizes that the difficulty of providing security increases with the complexity of the system. As you may have noticed, each new revision of an operating system provides about a 4X increase of lines of code (in the case of Windows). Security is always in a catch-up race with the ability of criminals to find and exploit faults. Please pardon this intrusion into the world of precision time, but the issue was raised here. As a designer of industrial control systems, I've made it a point to study security, and found Schneier to be a fount of information. Perhaps a disclaimer is in order. I do not know Schneier and receive nothing from plugging his work. Bill Hawkins ___ 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] Need some wisdom from the cesium beam tube gurus out there
It would work as well if you used a pair of regular copper wires to connect the meter to the thermocouple... The junctions created by all the new connections will cancel out. Mike On 10/11/2016 20:53, cdel...@juno.com wrote: Skip, The easiest way to determine the oven resistor values for an unmarked tube is to directly measure the oven temperature and select a resistance to set it at the temperature you want. Your tube is a STD tube so I'd set it at 90 degrees C. Take a thermocouple meter and thermocouple and cut the junction off the end of the thermocouple. Attach a couple tiny alligator clips or grabbers. Next look at the potting around where the tubes cables come out. You should see short stubs of two different color wires peeking out of the potting. These are the ends of a thermocouple connected directly to the oven housing! I can't remember which type thermocouple it is. (I'll look in my notes and at the meter I use and let you know!) Connect the wires to your meter matching the color of the wires. Now with the tube cold you should see the ambient temperature on the meter. Power up the unit and you will see the temp start to rise. It will stabilize at the point determined by the resistance you selected. If too hot increase the resistance if too cold decrease. Cheers, Corby ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Sapphire whispering gallery mode masers?
The recent mention of WGM sapphire oscillators and recent threads about time-nut constructable secondary frequency standards reminded me of a paper I ran into a while back about a WGM maser. The mechanical of the device were similar to an ordinary WGM oscillator: cryocooled sapphire crystal in a vacuum. But electronically it was pretty different, a dopant in the crystal could be RF pumped at some frequency far away from one of the normal high-Q modes of the oscillator and formed a three-stage laser whos emission bandwidth included the normal (~10GHz) high-Q WGM, which it would then happily lase at. They reported that the signal power was significantly higher than a AHM. The advantage of the construction is that the maser level is controlled by saturation, and so it was not very sensitive to the intensity stability of the pump. It seemed to me that it might be a possible candidate for a difficult but achievable 'home' experiment for an oscillator with exceptional short to medium term stability in a way that something like a hydrogen maser isn't. (Then again, I've never worked with anything cooler than LN2). Unfortunately I can't find the paper, but I doubt I dreamed it. ___ 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] Nutty time-nuttery with WWVB
On 11/10/2016 05:46 PM, Tom Van Baak wrote: To be honest, this is very impractical and backward-thinking. I would suggest instead upgrading to the Internet-of-things paradigm, replacing these time-of-day displays with full computers running NTP and connected to your LAN (Android smartwatches; repurposed old smartphones, tablets, laptops, etc.; and smartclocks Hi Ruslan, Please tell me this comment is humor or maybe just trolling. Or are you actually serious? I am absolutely serious. -Ruslan ___ 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] Nutty time-nuttery with WWVB
On 11/10/2016 05:10 PM, Artek Manuals wrote: I think you have missed the point this is not so much about keeping time down to the nano-second I was suggesting NTP, not PTP. The WWVB clocks being discussed here come in a plethora of decorator styles and display varieties ( though most are old analog dials) some up to 3' in diameter.. They are battery powered so one does not have to connect them to external power source. They serve a dual purpose for the lady friends who keep us fat and happy they are pleasing to the their sense of form and feng shui (If momma aint happy ..aint nobody happy) Then find a more rationally-minded wife or partner. . For the engineer in us we know that the time is accurate to the second and we don't have get out the step ladder to crawl up there and reset the clock twice a year when daylight savings changes over. When I was a road warrior I had a wrist watch that kept WWVB time and I always knew down to the second how much time I had before I missed the next flight or train out of Dodge. ( I haven't worn a watch by the way since I retired in 2008 !) Nowadays I suppose you could build/buy one that talks to your WLAN but I suspect the battery life is not quite as good as the current WWVB version which can run off a watch battery for 5 years. Well you would have to bother with the rather-pointless project of building a WWVB simulator, taking care not to cause interference. Stationary clocks do not have to be battery-powered. Yes, battery life would obviously be a problem for typical smartwatches, but assuming a rational mind, virtually everyone will opt for a smartwatch over a WWVB-synchronized dumbwatch, despite the battery life penalty incurred. On the other hand I know I can sleep better at night knowing my WWVB clock has not joined the dark side and is mindlessly helping the terrorists bring down the power grid 8^( What a brilliant idea---lets refuse to embrace computerization and the transition to Internet-of-things (which should've happened in the 80s) out of fear of the expansion of botnets; furthermore, lets roll back computerization, and maybe even eliminate all computers? Why have progress when we can have regress? Of course, we shall disregard the fact that there are a wide array of all sorts of security countermeasures (correctness proofs, sourcecode auditing, multifactor authentication, ASLR, DoD-style MACs, firewalls, IDSs, honeypots, tarpits, etc.) and the fact that all properly-designed high-security and/or critical systems are either completely air-gapped (SIPRNet, JWICS, NSANet, stock exchange internal networks, etc.), or are unidirectionally interfaced with the Internet (many SCADA sites, etc.) -Ruslan ___ 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] China Oscillator Alternative
I looked at this when it was mentioned here a few weeks ago. I did the procedure in an hour or so and it's working well, keeping the PPS within 50ns of GPS with 6-8 satellites. Monitored by the patched version of Z38XX at the moment though I look forward to putting Lady Heather on the job. The curious thing is, although that file is hosted on eevblog, I can't find any link to it from the forums. You have to know where to find it. http://www.eevblog.com/forum/testgear/economical-option-for-precision-frequency-reference/?action=dlattach;attach=172662 Perhaps we could get a copy on Didier's site (with the author, Peter Garde's permission) before it gets lost ? On Thu, Nov 10, 2016 at 6:19 PM, Mark Sims wrote: > Plus, you can add a Motrorla UT+ GPS receiver into the Z3812A and turn it > into a GPSDO. There is a nice writeup of the procedure on EEVBLOG. > Basically you move a half dozen 0 ohm resistors and add a resistor for the > antenna current sense circuit. > > Also, Lady Heather now talks to them. > ___ > 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] Nutty time-nuttery with WWVB
> To be honest, this is very impractical and backward-thinking. > I would suggest instead upgrading to the Internet-of-things paradigm, > replacing > these time-of-day displays with full computers running NTP and connected > to your LAN (Android smartwatches; repurposed old smartphones, tablets, > laptops, etc.; and smartclocks Hi Ruslan, Please tell me this comment is humor or maybe just trolling. Or are you actually serious? Thanks /tvb Moderator, http://leapsecond.com/time-nuts.htm ___ 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] Nutty time-nuttery with WWVB
Hi Pete: It's been 4 years since WWVB added phase modulation that's supposed to fix the East coast problem. Have you tried using a clock that makes use of it? For example the La Crosse Model # 404-1235UA-SS from Home Depot. I haven't got one yet since they are about $60 and my old style WWVB clocks work fine, but it would be a lot easier to get one as opposed to building something. -- Have Fun, Brooke Clarke http://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html The lesser of evils is still evil. Original Message I have a few of those "atomic" clocks that receive WWVB to set the time. However since I live on the east coast they may only pick up the signal once or twice per year. Could I implement my own personal WWVB transmitter that would be powerful enough to be picked up by the clocks in my house? The signal at 60 KHz might be able to be produced directly by some sound cards. With that and a ferrite rod antenna I might get reliable time elsewhere in my house outside of my lab. Has anyone tried this? Pete. ___ 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] Nutty time-nuttery with WWVB
Hi > On Nov 10, 2016, at 4:52 PM, Ruslan Nabioullin wrote: > > On 11/10/2016 07:18 AM, Peter Reilley wrote: >> I have a few of those "atomic" clocks that receive WWVB to set the time. >> However since I live on the east coast they may only pick up the signal >> once or twice per year. >> >> Could I implement my own personal WWVB transmitter that would >> be powerful enough to be picked up by the clocks in my house? >> The signal at 60 KHz might be able to be produced directly by some >> sound cards. With that and a ferrite rod antenna I might get >> reliable time elsewhere in my house outside of my lab. >> >> Has anyone tried this? >> >> Pete. > > To be honest, this is very impractical and backward-thinking. I would > suggest instead upgrading to the Internet-of-things paradigm, replacing these > time-of-day displays with full computers running NTP and connected to your > LAN (Android smartwatches; repurposed old smartphones, tablets, laptops, > etc.; and smartclocks Ok, I have one to two dozen clocks around here that sync to WWVB. I swap out batteries every few years and they all keep chunking along. No wires to any of them. No updates or patching on a regular basis. They each have nice useful displays that make sense for their location. The cost for the batch of them was < $400 and that was over a 10 to 20 year span. I have yet to see one of them die. If I replace all of them with computers, they all need displays on them. Not small displays, but displays that I can see from across the room. The display on a phone or an old tablet isn’t going to cut it. I will now be running / patching Linux on all those devices so none of them are exactly small machines attached to the displays. I have a number of NTP servers running around so yes, I have a pretty good idea what the hardware will look like. I need to get power and network to each clock location. Unless I really enjoy WiFI nonsense, I’ll hard wire them. I also need to work out how to mount the displays and the computers in each location. There is the minor issue of errr … money. If each display is $100 and the Beagle Bone is $50, 24 of them will run me $3600. There will be another ethernet switch in the mix as well. There will be power supplies, mounting boxes and other stuff. They each will pull at least 50 W with the monitor on. That’s 1.2 KW at 10 cents a KW plus tax plus air conditioning in the summer, call it 20 cents a KWH. That is about $2.1K a year. Over 10 years it’s another $21K. So what do I get with my investment? I get a bunch of displays that aren’t going to last five years of 24/7/365 operation (let alone 10 or 20 years). I get a bunch of night lights in places they are not useful (or wanted). I get a system that is less reliable than what I had. I get to have even more fun patching and debugging everything on a regular basis. I get a bunch of clocks that are ugly compared to what is there now. Hmmm ….. why would I do this? Bob > [I'm certain that some Silicon Valley ``genius'' has already come out with > such an ``invention'' and the Chinese are churning out cheap knockoffs]), > which will query your home metrology lab's NTP server(s), and instead using > WWVB as an additional timing signal for diversifying your timing source > portfolio (with a good antenna, of course), if you haven't done so already > (though such products appear to be extremely sparse nowadays, for > civilian-minded users have superficially reasoned that GPS is all that is > necessary). > > -Ruslan > ___ > 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] Need some wisdom from the cesium beam tube gurus out there
In the whacky world of thermocouple color codes, the RED wire is usually the negative! The other wire color is usually an indication of the thermocouple type. YMMV... nothing is hard and fast about thermocouple colors. --- > Connect the wires to your meter matching the color of the wires. ___ 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] Nutty time-nuttery with WWVB
On 11/10/2016 4:52 PM, Ruslan Nabioullin wrote: On 11/10/2016 07:18 AM, Peter Reilley wrote: I have a few of those "atomic" clocks that receive WWVB to set the time. However since I live on the east coast they may only pick up the signal once or twice per year. Could I implement my own personal WWVB transmitter that would be powerful enough to be picked up by the clocks in my house? The signal at 60 KHz might be able to be produced directly by some sound cards. With that and a ferrite rod antenna I might get reliable time elsewhere in my house outside of my lab. Has anyone tried this? Pete. To be honest, this is very impractical and backward-thinking. I would suggest instead upgrading to the Internet-of-things paradigm, replacing these time-of-day displays with full computers running NTP and connected to your LAN (Android smartwatches; repurposed old smartphones, tablets, laptops, etc.; and smartclocks [I'm certain that some Silicon Valley ``genius'' has already come out with such an ``invention'' and the Chinese are churning out cheap knockoffs]), which will query your home metrology lab's NTP server(s), and instead using WWVB as an additional timing signal for diversifying your timing source portfolio (with a good antenna, of course), if you haven't done so already (though such products appear to be extremely sparse nowadays, for civilian-minded users have superficially reasoned that GPS is all that is necessary). -Ruslan ___ 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. Ruslan I think you have missed the point this is not so much about keeping time down to the nano-second The WWVB clocks being discussed here come in a plethora of decorator styles and display varieties ( though most are old analog dials) some up to 3' in diameter.. They are battery powered so one does not have to connect them to external power source. They serve a dual purpose for the lady friends who keep us fat and happy they are pleasing to the their sense of form and feng shui (If momma aint happy ..aint nobody happy) . For the engineer in us we know that the time is accurate to the second and we don't have get out the step ladder to crawl up there and reset the clock twice a year when daylight savings changes over. When I was a road warrior I had a wrist watch that kept WWVB time and I always knew down to the second how much time I had before I missed the next flight or train out of Dodge. ( I haven't worn a watch by the way since I retired in 2008 !) Nowadays I suppose you could build/buy one that talks to your WLAN but I suspect the battery life is not quite as good as the current WWVB version which can run off a watch battery for 5 years. On the other hand I know I can sleep better at night knowing my WWVB clock has not joined the dark side and is mindlessly helping the terrorists bring down the power grid 8^( Cheers Dave -- Dave manu...@artekmanuals.com www.ArtekManuals.com ___ 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] Nutty time-nuttery with WWVB
On 11/10/2016 07:18 AM, Peter Reilley wrote: I have a few of those "atomic" clocks that receive WWVB to set the time. However since I live on the east coast they may only pick up the signal once or twice per year. Could I implement my own personal WWVB transmitter that would be powerful enough to be picked up by the clocks in my house? The signal at 60 KHz might be able to be produced directly by some sound cards. With that and a ferrite rod antenna I might get reliable time elsewhere in my house outside of my lab. Has anyone tried this? Pete. To be honest, this is very impractical and backward-thinking. I would suggest instead upgrading to the Internet-of-things paradigm, replacing these time-of-day displays with full computers running NTP and connected to your LAN (Android smartwatches; repurposed old smartphones, tablets, laptops, etc.; and smartclocks [I'm certain that some Silicon Valley ``genius'' has already come out with such an ``invention'' and the Chinese are churning out cheap knockoffs]), which will query your home metrology lab's NTP server(s), and instead using WWVB as an additional timing signal for diversifying your timing source portfolio (with a good antenna, of course), if you haven't done so already (though such products appear to be extremely sparse nowadays, for civilian-minded users have superficially reasoned that GPS is all that is necessary). -Ruslan ___ 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] Nutty time-nuttery with WWVB
basically one could make a very good 60kHz clock distributor system, by running a large loop around the property, -- as long as the loop's length is much less than the wave length the current will be constant along the loop -- that way you will have reception inside the loop with vertical magnetic, and very weak reception outside of the loop. At the clocks you need to turn the antenna from horizontal to vertical, and you could use such low power a few mW, that the FCC would not worry about it, similar system is used as invisible fence for dogs, but for the clock one need much less power, since the clocks have a very sensitive receiver unlike the "dogs receiver". 73 KJ6UHN Alex alias Dr.Alexander Pummer, PCS Consultants Pleasanton On 11/10/2016 10:45 AM, Van Horn, David wrote: I have, for many years, wished the FCC would get serious on enforcement. I've dealt with CEOs who said basically "ok, so it's illegal, who's going to catch us?" I have on occasion had to physically stop shipments from being made. If we had enforcement with TEETH then it would be easy to make the case to management that they stand a good chance of getting spanked in the wallet. That's the only place a corporation has pain receptors. ___ 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. - No virus found in this message. Checked by AVG - www.avg.com Version: 2016.0.7859 / Virus Database: 4664/13383 - Release Date: 11/10/16 ___ 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] Nutty time-nuttery with WWVB
Well, there is such zoo, that nobody could find what coming from where, I tried with an R&S EMI receiver and antennas, but on the other hand one could use the high level of energy to supply the power for small circuits 73 KJ6UHN Alex On 11/10/2016 10:15 AM, Clint Jay wrote: Don't forget power line networking equipment but just because one interference source is tolerated or in order by the authorities doesn't mean it's ok to create another. Those switchers and even the hardware they power (I'm thinking of satellite receivers which spew all sorts of hash over HF bands) are terrible sources of unmonitored QRM. On 10 Nov 2016 17:46, "Alex Pummer" wrote: And how about that many, many "radiator" which are moving up and down with their carriers and don't give a damn about FCC Part 15 and radiating radiating day and night with substantial power, I meant that FFC approved and not approved switching mode power supplies, of which every household has a hand full of it? 73 KJ6UHN Alex On 11/10/2016 9:22 AM, William H. Fite wrote: I heartily second Charles' admonition regarding FCC PART 15 unlicensed transmissions. Part 15 explicitly states that an unlicensed operator may not cause interference with any licensed transmission. Because of the specific purpose of WWV/WWVB transmissions, any discernible leakage detectable by any other user is prima facie evidence of unlawful transmission and subject to a heavy fine. I assure you that any licensed Part 97 user who detects your emissions over the top of WWVB is quite likely to rat you out to Uncle Charlie. And should, may I say, because you will be interfering with a public service. "I am just syncing my clocks" is not going to impress the guys who appear in your driveway in a white van with RDF antennas on the roof. Sobe very damned sure that you are not radiating a discernible signal outside of the immediate vicinity of your clocks. Bill KJ4SLP On Thursday, November 10, 2016, Charles Steinmetz wrote: Peter wrote: Could I implement my own personal WWVB transmitter that would be powerful enough to be picked up by the clocks in my house? * * * Has anyone tried this? Some on the list have, and I'm sure they will provide the details. Others have mentioned the potential problems with interference to other WWVB users. For starters, make sure you study and understand Part 15 of the FCC rules before you put it on the air, or you could face a nasty enforcement action. (Even if you are Part 15-compliant, you may still screw up other users' reception and get a visit from the FCC when they complain. I operate several very sensitive 60kHz receivers -- if you live in my neighborhood, I'm almost certain to be unhappy about anything you deploy.) Note that the problem with most "atomic" clocks that I've seen is actually not insufficient signal (in the wee hours of the morning, when they try to synch). It is either excessive QRM, or orienting the clock so its antenna has a null toward Fort Collins. Make sure the antenna has a major lobe toward Fort Collins (this may require relocating the entire clock or bringing the antenna out so you can orient it independently), and that it is well clear of the AC mains distribution wiring in your house and any other sources of QRM (wall warts, CFL lamps, LED lamps, etc. (this may also require relocating the clock). The typical clock using a loopstick antenna has lobes to the front and rear, and nulls to the sides. Thus, mounting the clock on the western exterior wall (for users on the east coast) is usually best. Putting it directly in front of a west-facing window may help. Best regards, Charles ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/m ailman/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/m ailman/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. - No virus found in this message. Checked by AVG - www.avg.com Version: 2016.0.7859 / Virus Database: 4664/13383 - Release Date: 11/10/16 ___ 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] Need some wisdom from the cesium beam tube gurus out there
Skip, The easiest way to determine the oven resistor values for an unmarked tube is to directly measure the oven temperature and select a resistance to set it at the temperature you want. Your tube is a STD tube so I'd set it at 90 degrees C. Take a thermocouple meter and thermocouple and cut the junction off the end of the thermocouple. Attach a couple tiny alligator clips or grabbers. Next look at the potting around where the tubes cables come out. You should see short stubs of two different color wires peeking out of the potting. These are the ends of a thermocouple connected directly to the oven housing! I can't remember which type thermocouple it is. (I'll look in my notes and at the meter I use and let you know!) Connect the wires to your meter matching the color of the wires. Now with the tube cold you should see the ambient temperature on the meter. Power up the unit and you will see the temp start to rise. It will stabilize at the point determined by the resistance you selected. If too hot increase the resistance if too cold decrease. Cheers, Corby ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Fluke Voltage Standards.
On Thursday, November 10, 2016 02:23:19 PM xaos wrote: > I wonder if there is a way to get a voltage standard out of a frequency > standard (GPS Disciplined). > I think the big problem is probably voltage stability due to temperature > variations. > > Any thoughts on this ? > > -George > > On 11/10/2016 02:17 PM, paul swed wrote: > > Perry, > > Thanks for pointing them out. Very tempting. But that said what I really > > liked was the 2012 tour pixs on the site. > > I would have some serious fun going through that place and loading up my > > trunk. > > But thats 11 drive hours away. Maybe not this week. > > I have purchased various items from Fair Radio and though I am sure you > > could get burned the fact is I never have been. They are pretty upfront on > > the risk. > > The killer for me is the shipping on about anything they have costs more > > then the usable value of the equipment. He at ham prices. > > Regards > > Paul > > WB8TSL > > > > On Thu, Nov 10, 2016 at 2:32 AM, Bill Hawkins wrote: > >> Had the HP equivalent for a while. Required special cords to bring the > >> voltage to the DUT. Buyer Beware. > >> Haven't seen a Fair Radio catalog in years, not since I sold the R-39x > >> equipment. > >> > >> There's a big difference between the accuracy of a voltage standard and > >> a time standard. > >> Perhaps this is because there are no satellites broadcasting voltage > >> standards. > >> > >> Bill Hawkins > >> > >> > >> -Original Message- > >> From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Perry > >> Sandeen via time-nuts > >> Sent: Wednesday, November 09, 2016 6:26 PM > >> > >> List, > >> Fair Radio which has been in the surplus electronics business almost > >> forever has two models of Fluke standards for sale. They have a sterling > >> reputation. > >> FLUKE-332A $100 Voltage Standard - Used Reparable > >> > >> FLUKE-332B $125 Voltage Standard - Used Reparable > >> > >> > >> IIRC, this means they will work but are not calibrated. If interested > >> one can email them for exactly what Used Repairable means. > >> FWIW > >> Regards, > >> Perrier > >> > >> ___ > >> 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. Only the obvious method of using a Josephson Junction series array. Bruce ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Nutty time-nuttery with WWVB
Alex wrote: And how about that many, many "radiator" which are moving up and down with their carriers and don't give a damn about FCC Part 15 and radiating radiating day and night with substantial power, I meant that FFC approved and not approved switching mode power supplies SMPSs are "incidental radiators" under Part 15 (these days, some are "unintentional radiators"). As a practical matter, the Enforcement Division takes "intentional radiators" (like a WWVB simulator or re-transmitter, or a pirate radio station) much more seriously than IRs and URs. Best regards, Charles ___ 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] Fluke Voltage Standards.
In message <9dbb3a8f-d529-7b70-6e06-de4ea3507...@darksmile.net>, xaos writes: >I wonder if there is a way to get a voltage standard out of a frequency >standard (GPS Disciplined). >I think the big problem is probably voltage stability due to temperature >variations. There is, it's called a Josephson Junction. I think volt-nuts recently concluded that prices start from about $50k... -- 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] Fluke Voltage Standards.
I wonder if there is a way to get a voltage standard out of a frequency standard (GPS Disciplined). I think the big problem is probably voltage stability due to temperature variations. Any thoughts on this ? -George On 11/10/2016 02:17 PM, paul swed wrote: > Perry, > Thanks for pointing them out. Very tempting. But that said what I really > liked was the 2012 tour pixs on the site. > I would have some serious fun going through that place and loading up my > trunk. > But thats 11 drive hours away. Maybe not this week. > I have purchased various items from Fair Radio and though I am sure you > could get burned the fact is I never have been. They are pretty upfront on > the risk. > The killer for me is the shipping on about anything they have costs more > then the usable value of the equipment. He at ham prices. > Regards > Paul > WB8TSL > > On Thu, Nov 10, 2016 at 2:32 AM, Bill Hawkins wrote: > >> Had the HP equivalent for a while. Required special cords to bring the >> voltage to the DUT. Buyer Beware. >> Haven't seen a Fair Radio catalog in years, not since I sold the R-39x >> equipment. >> >> There's a big difference between the accuracy of a voltage standard and >> a time standard. >> Perhaps this is because there are no satellites broadcasting voltage >> standards. >> >> Bill Hawkins >> >> >> -Original Message- >> From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Perry >> Sandeen via time-nuts >> Sent: Wednesday, November 09, 2016 6:26 PM >> >> List, >> Fair Radio which has been in the surplus electronics business almost >> forever has two models of Fluke standards for sale. They have a sterling >> reputation. >> FLUKE-332A $100 Voltage Standard - Used Reparable >> >> FLUKE-332B $125 Voltage Standard - Used Reparable >> >> >> IIRC, this means they will work but are not calibrated. If interested >> one can email them for exactly what Used Repairable means. >> FWIW >> Regards, >> Perrier >> >> ___ >> 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] Fluke Voltage Standards.
Perry, Thanks for pointing them out. Very tempting. But that said what I really liked was the 2012 tour pixs on the site. I would have some serious fun going through that place and loading up my trunk. But thats 11 drive hours away. Maybe not this week. I have purchased various items from Fair Radio and though I am sure you could get burned the fact is I never have been. They are pretty upfront on the risk. The killer for me is the shipping on about anything they have costs more then the usable value of the equipment. He at ham prices. Regards Paul WB8TSL On Thu, Nov 10, 2016 at 2:32 AM, Bill Hawkins wrote: > Had the HP equivalent for a while. Required special cords to bring the > voltage to the DUT. Buyer Beware. > Haven't seen a Fair Radio catalog in years, not since I sold the R-39x > equipment. > > There's a big difference between the accuracy of a voltage standard and > a time standard. > Perhaps this is because there are no satellites broadcasting voltage > standards. > > Bill Hawkins > > > -Original Message- > From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Perry > Sandeen via time-nuts > Sent: Wednesday, November 09, 2016 6:26 PM > > List, > Fair Radio which has been in the surplus electronics business almost > forever has two models of Fluke standards for sale. They have a sterling > reputation. > FLUKE-332A $100 Voltage Standard - Used Reparable > > FLUKE-332B $125 Voltage Standard - Used Reparable > > > IIRC, this means they will work but are not calibrated. If interested > one can email them for exactly what Used Repairable means. > FWIW > Regards, > Perrier > > ___ > 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] Nutty time-nuttery with WWVB
I have, for many years, wished the FCC would get serious on enforcement. I've dealt with CEOs who said basically "ok, so it's illegal, who's going to catch us?" I have on occasion had to physically stop shipments from being made. If we had enforcement with TEETH then it would be easy to make the case to management that they stand a good chance of getting spanked in the wallet. That's the only place a corporation has pain receptors. ___ 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] How to get PPS from ublox mini-PCI GPS to APU2 SoC serial port for ntpd
Yo Hal! albertson.ch...@gmail.com said: > If using the PPS for timing and the PPS is inverted you will have > to measure the delay length an account for in the config file. Or use gpsd to do the PPS detection. It automagiaclly selects the proper edge. RGDS GARY --- Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97703 g...@rellim.com Tel:+1 541 382 8588 pgp14VrfFkEHX.pgp Description: OpenPGP digital signature ___ 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] Nutty time-nuttery with WWVB
Don't forget power line networking equipment but just because one interference source is tolerated or in order by the authorities doesn't mean it's ok to create another. Those switchers and even the hardware they power (I'm thinking of satellite receivers which spew all sorts of hash over HF bands) are terrible sources of unmonitored QRM. On 10 Nov 2016 17:46, "Alex Pummer" wrote: > And how about that many, many "radiator" which are moving up and down with > their carriers and don't give a damn about FCC Part 15 and radiating > radiating day and night with substantial power, I meant that FFC approved > and not approved switching mode power supplies, of which every household > has a hand full of it? > > 73 > KJ6UHN > Alex > > On 11/10/2016 9:22 AM, William H. Fite wrote: > >> I heartily second Charles' admonition regarding FCC PART 15 unlicensed >> transmissions. Part 15 explicitly states that an unlicensed operator may >> not cause interference with any licensed transmission. Because of the >> specific purpose of WWV/WWVB transmissions, any discernible leakage >> detectable by any other user is prima facie evidence of unlawful >> transmission and subject to a heavy fine. I assure you that any licensed >> Part 97 user who detects your emissions over the top of WWVB is quite >> likely to rat you out to Uncle Charlie. And should, may I say, because you >> will be interfering with a public service. "I am just syncing my clocks" >> is >> not going to impress the guys who appear in your driveway in a white van >> with RDF antennas on the roof. >> >> Sobe very damned sure that you are not radiating a discernible signal >> outside of the immediate vicinity of your clocks. >> >> Bill >> KJ4SLP >> >> >> >> On Thursday, November 10, 2016, Charles Steinmetz >> wrote: >> >> Peter wrote: >>> >>> Could I implement my own personal WWVB transmitter that would >>> be powerful enough to be picked up by the clocks in my house? * * * Has anyone tried this? Some on the list have, and I'm sure they will provide the details. >>> >>> Others have mentioned the potential problems with interference to other >>> WWVB users. For starters, make sure you study and understand Part 15 of >>> the FCC rules before you put it on the air, or you could face a nasty >>> enforcement action. (Even if you are Part 15-compliant, you may still >>> screw up other users' reception and get a visit from the FCC when they >>> complain. I operate several very sensitive 60kHz receivers -- if you >>> live >>> in my neighborhood, I'm almost certain to be unhappy about anything you >>> deploy.) >>> >>> Note that the problem with most "atomic" clocks that I've seen is >>> actually >>> not insufficient signal (in the wee hours of the morning, when they try >>> to >>> synch). It is either excessive QRM, or orienting the clock so its >>> antenna >>> has a null toward Fort Collins. Make sure the antenna has a major lobe >>> toward Fort Collins (this may require relocating the entire clock or >>> bringing the antenna out so you can orient it independently), and that it >>> is well clear of the AC mains distribution wiring in your house and any >>> other sources of QRM (wall warts, CFL lamps, LED lamps, etc. (this may >>> also >>> require relocating the clock). >>> >>> The typical clock using a loopstick antenna has lobes to the front and >>> rear, and nulls to the sides. Thus, mounting the clock on the western >>> exterior wall (for users on the east coast) is usually best. Putting it >>> directly in front of a west-facing window may help. >>> >>> Best regards, >>> >>> Charles >>> >>> >>> ___ >>> time-nuts mailing list -- time-nuts@febo.com >>> To unsubscribe, go to https://www.febo.com/cgi-bin/m >>> ailman/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/m > ailman/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] China Oscillator Alternative
Plus, you can add a Motrorla UT+ GPS receiver into the Z3812A and turn it into a GPSDO. There is a nice writeup of the procedure on EEVBLOG. Basically you move a half dozen 0 ohm resistors and add a resistor for the antenna current sense circuit. Also, Lady Heather now talks to them. ___ 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] Nutty time-nuttery with WWVB
It sure would. FCC has just given up on 11M. Guys in Florida with generators and radios in their pick-em-up trucks driving on the beach and emitting 2KW. On Thu, Nov 10, 2016 at 12:51 PM, Van Horn, David < david.vanh...@backcountryaccess.com> wrote: > > Enforcement.. It would be nice. > > > -Original Message- > From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Alex > Pummer > Sent: Thursday, November 10, 2016 10:39 AM > To: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] Nutty time-nuttery with WWVB > > And how about that many, many "radiator" which are moving up and down with > their carriers and don't give a damn about FCC Part 15 and radiating > radiating day and night with substantial power, I meant that FFC approved > and not approved switching mode power supplies, of which every household > has a hand full of it? > > 73 > KJ6UHN > Alex > > On 11/10/2016 9:22 AM, William H. Fite wrote: > > I heartily second Charles' admonition regarding FCC PART 15 unlicensed > > transmissions. Part 15 explicitly states that an unlicensed operator > > may not cause interference with any licensed transmission. Because of > > the specific purpose of WWV/WWVB transmissions, any discernible > > leakage detectable by any other user is prima facie evidence of > > unlawful transmission and subject to a heavy fine. I assure you that > > any licensed Part 97 user who detects your emissions over the top of > > WWVB is quite likely to rat you out to Uncle Charlie. And should, may > > I say, because you will be interfering with a public service. "I am > > just syncing my clocks" is not going to impress the guys who appear in > > your driveway in a white van with RDF antennas on the roof. > > > > Sobe very damned sure that you are not radiating a discernible > > signal outside of the immediate vicinity of your clocks. > > > > Bill > > KJ4SLP > > > > > > > > On Thursday, November 10, 2016, Charles Steinmetz > > > > wrote: > > > >> Peter wrote: > >> > >> Could I implement my own personal WWVB transmitter that would > >>> be powerful enough to be picked up by the clocks in my house? > >>> * * * > >>> Has anyone tried this? > >>> > >> Some on the list have, and I'm sure they will provide the details. > >> > >> Others have mentioned the potential problems with interference to > >> other WWVB users. For starters, make sure you study and understand > >> Part 15 of the FCC rules before you put it on the air, or you could > >> face a nasty enforcement action. (Even if you are Part 15-compliant, > >> you may still screw up other users' reception and get a visit from > >> the FCC when they complain. I operate several very sensitive 60kHz > >> receivers -- if you live in my neighborhood, I'm almost certain to be > >> unhappy about anything you > >> deploy.) > >> > >> Note that the problem with most "atomic" clocks that I've seen is > >> actually not insufficient signal (in the wee hours of the morning, > >> when they try to synch). It is either excessive QRM, or orienting > >> the clock so its antenna has a null toward Fort Collins. Make sure > >> the antenna has a major lobe toward Fort Collins (this may require > >> relocating the entire clock or bringing the antenna out so you can > >> orient it independently), and that it is well clear of the AC mains > >> distribution wiring in your house and any other sources of QRM (wall > >> warts, CFL lamps, LED lamps, etc. (this may also require relocating the > clock). > >> > >> The typical clock using a loopstick antenna has lobes to the front > >> and rear, and nulls to the sides. Thus, mounting the clock on the > >> western exterior wall (for users on the east coast) is usually best. > >> Putting it directly in front of a west-facing window may help. > >> > >> Best regards, > >> > >> Charles > >> > >> > >> ___ > >> time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to > >> https://www.febo.com/cgi-bin/m ailman/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. > -- Intelligence has never been proof against stupidity. ___ 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] Nutty time-nuttery with WWVB
Hi This is worth repeating…. > On Nov 10, 2016, at 11:03 AM, Charles Steinmetz wrote: > > Peter wrote: > >> Could I implement my own personal WWVB transmitter that would >> be powerful enough to be picked up by the clocks in my house? >> * * * >> Has anyone tried this? > > Some on the list have, and I'm sure they will provide the details. > > Others have mentioned the potential problems with interference to other WWVB > users. For starters, make sure you study and understand Part 15 of the FCC > rules before you put it on the air, or you could face a nasty enforcement > action. (Even if you are Part 15-compliant, you may still screw up other > users' reception and get a visit from the FCC when they complain. I operate > several very sensitive 60kHz receivers -- if you live in my neighborhood, I'm > almost certain to be unhappy about anything you deploy.) > > Note that the problem with most "atomic" clocks that I've seen is actually > not insufficient signal (in the wee hours of the morning, when they try to > synch). The WWVB signal (even on the east coast) is quite massive in the middle of the night. The same can be said of the MSF signal from across the Atlantic, The problem is unlikely to be insufficient signal. Bob > It is either excessive QRM, or orienting the clock so its antenna has a null > toward Fort Collins. Make sure the antenna has a major lobe toward Fort > Collins (this may require relocating the entire clock or bringing the antenna > out so you can orient it independently), and that it is well clear of the AC > mains distribution wiring in your house and any other sources of QRM (wall > warts, CFL lamps, LED lamps, etc. (this may also require relocating the > clock). > > The typical clock using a loopstick antenna has lobes to the front and rear, > and nulls to the sides. Thus, mounting the clock on the western exterior > wall (for users on the east coast) is usually best. Putting it directly in > front of a west-facing window may help. > > Best regards, > > Charles > > > ___ > 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] How to get PPS from ublox mini-PCI GPS to APU2 SoC serial port for ntpd
Hi Well, I have yet to test a gps module that does not have a *very* accurate pulse width out of it. Same with GPSDO’s. Yes, It’s something I look at. Bob > On Nov 10, 2016, at 10:22 AM, Chris Albertson > wrote: > > The problem here is "real world". Yes in theory you can do it perfectly > but in the real world do all makes and models of GPS receivers get it > right? I would not bet on it. > > This is just like the argument over using NMEA only for timing. Some GPS > receivers push out NEMA sentences with very little jitter and others only > follow the NMEA spec with only requires plus or minus one second accuracy > and then there is every shade of grey between. > > My conservative engineering background tells me that unless the variation > of the pulse width is species you should assume the width is not controlled > at all. It may even look good in testing but a firmware update would kill > that. Likely in there is no regression test for not specified features. > People now days who write software (or firmware especially) will build an > automated test suit that lets them checks f the software still works after > making changes. They are careful to test each written requirement. > > The UART on the PC can interrupt on either raising or facing edges so if > the PPS is inverted you interrupt on the falling edge. But you have to > get this right too > > one IMPORTENT thing to get right is to remember that on modern control > line under RS232 the logic is "active low". TTL logic is "active high" > where a higher voltage means "one" and allow voltage means "zero" but this > is backwards for modern control under RS232 So, it is WAY-EASY to get it > wrong when connecting a TTL PPS to a modern control line. You might > need an inverter because many level shifters invert the signal > > The one thing that helps is the at 1Hz the signal is slow enough to see on > a volt meter, Even an old VTVM reacts fast enough > > On Wed, Nov 9, 2016 at 2:44 PM, Tom Van Baak wrote: > >> Bob, >> >> The PIC's I use have essentially no jitter. If they generate a 1PPS the >> edge and the pulse width are perfect, down to picoseconds. The talk about >> "other stuff" and "priority" and "number of compares" and "ambiguity" is >> worrisome. It sounds like a design or coding flaw to me, like what happens >> when people try to do precise time with a high level language. >> >> /tvb >> >> - Original Message - >> From: "Bob Stewart" >> To: "Discussion of precise time and frequency measurement" < >> time-nuts@febo.com> >> Sent: Wednesday, November 09, 2016 9:30 AM >> Subject: Re: [time-nuts] How to get PPS from ublox mini-PCI GPS to APU2 >> SoC serial port for ntpd >> >> >> I'd like to comment on the idea of measuring the width of the pulse. My >> experience with creating the 1PPS from an interrupt is that it's fairly >> straightforward how to do the set interrupt: The interrupt happens, you >> execute one, maybe two instructions to raise the output pin, and you leave >> the interrupt routine. But, resetting the pin is a different story. Unless >> you've got a lot of interrupt vectors to play with, the reset part of the >> 1PPS signal is delegated to a general purpose timing interrupt where you're >> doing a lot of other stuff - and it has a somewhat lower priority. So, you >> wind up doing a number of compares to see if you should reset the pin, >> which adds some ambiguity to the set/reset times. >> Granted, I'm doing this on a general purpose PIC, but I have read comments >> about various receivers having some jitter on the reset side of their 1PPS >> pulse. >> Bob >> >> ___ >> 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. >> > > > > -- > > Chris Albertson > Redondo Beach, California > ___ > 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] Nutty time-nuttery with WWVB
Peter wrote: Could I implement my own personal WWVB transmitter that would be powerful enough to be picked up by the clocks in my house? * * * Has anyone tried this? Some on the list have, and I'm sure they will provide the details. Others have mentioned the potential problems with interference to other WWVB users. For starters, make sure you study and understand Part 15 of the FCC rules before you put it on the air, or you could face a nasty enforcement action. (Even if you are Part 15-compliant, you may still screw up other users' reception and get a visit from the FCC when they complain. I operate several very sensitive 60kHz receivers -- if you live in my neighborhood, I'm almost certain to be unhappy about anything you deploy.) Note that the problem with most "atomic" clocks that I've seen is actually not insufficient signal (in the wee hours of the morning, when they try to synch). It is either excessive QRM, or orienting the clock so its antenna has a null toward Fort Collins. Make sure the antenna has a major lobe toward Fort Collins (this may require relocating the entire clock or bringing the antenna out so you can orient it independently), and that it is well clear of the AC mains distribution wiring in your house and any other sources of QRM (wall warts, CFL lamps, LED lamps, etc. (this may also require relocating the clock). The typical clock using a loopstick antenna has lobes to the front and rear, and nulls to the sides. Thus, mounting the clock on the western exterior wall (for users on the east coast) is usually best. Putting it directly in front of a west-facing window may help. Best regards, Charles ___ 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] Nutty time-nuttery with WWVB
Enforcement.. It would be nice. -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Alex Pummer Sent: Thursday, November 10, 2016 10:39 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Nutty time-nuttery with WWVB And how about that many, many "radiator" which are moving up and down with their carriers and don't give a damn about FCC Part 15 and radiating radiating day and night with substantial power, I meant that FFC approved and not approved switching mode power supplies, of which every household has a hand full of it? 73 KJ6UHN Alex On 11/10/2016 9:22 AM, William H. Fite wrote: > I heartily second Charles' admonition regarding FCC PART 15 unlicensed > transmissions. Part 15 explicitly states that an unlicensed operator > may not cause interference with any licensed transmission. Because of > the specific purpose of WWV/WWVB transmissions, any discernible > leakage detectable by any other user is prima facie evidence of > unlawful transmission and subject to a heavy fine. I assure you that > any licensed Part 97 user who detects your emissions over the top of > WWVB is quite likely to rat you out to Uncle Charlie. And should, may > I say, because you will be interfering with a public service. "I am > just syncing my clocks" is not going to impress the guys who appear in > your driveway in a white van with RDF antennas on the roof. > > Sobe very damned sure that you are not radiating a discernible > signal outside of the immediate vicinity of your clocks. > > Bill > KJ4SLP > > > > On Thursday, November 10, 2016, Charles Steinmetz > > wrote: > >> Peter wrote: >> >> Could I implement my own personal WWVB transmitter that would >>> be powerful enough to be picked up by the clocks in my house? >>> * * * >>> Has anyone tried this? >>> >> Some on the list have, and I'm sure they will provide the details. >> >> Others have mentioned the potential problems with interference to >> other WWVB users. For starters, make sure you study and understand >> Part 15 of the FCC rules before you put it on the air, or you could >> face a nasty enforcement action. (Even if you are Part 15-compliant, >> you may still screw up other users' reception and get a visit from >> the FCC when they complain. I operate several very sensitive 60kHz >> receivers -- if you live in my neighborhood, I'm almost certain to be >> unhappy about anything you >> deploy.) >> >> Note that the problem with most "atomic" clocks that I've seen is >> actually not insufficient signal (in the wee hours of the morning, >> when they try to synch). It is either excessive QRM, or orienting >> the clock so its antenna has a null toward Fort Collins. Make sure >> the antenna has a major lobe toward Fort Collins (this may require >> relocating the entire clock or bringing the antenna out so you can >> orient it independently), and that it is well clear of the AC mains >> distribution wiring in your house and any other sources of QRM (wall >> warts, CFL lamps, LED lamps, etc. (this may also require relocating the >> clock). >> >> The typical clock using a loopstick antenna has lobes to the front >> and rear, and nulls to the sides. Thus, mounting the clock on the >> western exterior wall (for users on the east coast) is usually best. >> Putting it directly in front of a west-facing window may help. >> >> Best regards, >> >> Charles >> >> >> ___ >> time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to >> https://www.febo.com/cgi-bin/m ailman/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] Nutty time-nuttery with WWVB
Granted that FCC does, at best, a spotty job of enforcement but when they strike, they strike without warning. They won't fine you on the first offense unless you do something really egregious but you will go on their shit list and, once you are on it, you stay on it forever. Besides which, "Everybody else does it" didn't work with your mom and it won't work with Uncle Charlie. On Thu, Nov 10, 2016 at 12:39 PM, Alex Pummer wrote: > And how about that many, many "radiator" which are moving up and down with > their carriers and don't give a damn about FCC Part 15 and radiating > radiating day and night with substantial power, I meant that FFC approved > and not approved switching mode power supplies, of which every household > has a hand full of it? > > 73 > KJ6UHN > Alex > > > On 11/10/2016 9:22 AM, William H. Fite wrote: > >> I heartily second Charles' admonition regarding FCC PART 15 unlicensed >> transmissions. Part 15 explicitly states that an unlicensed operator may >> not cause interference with any licensed transmission. Because of the >> specific purpose of WWV/WWVB transmissions, any discernible leakage >> detectable by any other user is prima facie evidence of unlawful >> transmission and subject to a heavy fine. I assure you that any licensed >> Part 97 user who detects your emissions over the top of WWVB is quite >> likely to rat you out to Uncle Charlie. And should, may I say, because you >> will be interfering with a public service. "I am just syncing my clocks" >> is >> not going to impress the guys who appear in your driveway in a white van >> with RDF antennas on the roof. >> >> Sobe very damned sure that you are not radiating a discernible signal >> outside of the immediate vicinity of your clocks. >> >> Bill >> KJ4SLP >> >> >> >> On Thursday, November 10, 2016, Charles Steinmetz >> wrote: >> >> Peter wrote: >>> >>> Could I implement my own personal WWVB transmitter that would >>> be powerful enough to be picked up by the clocks in my house? * * * Has anyone tried this? Some on the list have, and I'm sure they will provide the details. >>> >>> Others have mentioned the potential problems with interference to other >>> WWVB users. For starters, make sure you study and understand Part 15 of >>> the FCC rules before you put it on the air, or you could face a nasty >>> enforcement action. (Even if you are Part 15-compliant, you may still >>> screw up other users' reception and get a visit from the FCC when they >>> complain. I operate several very sensitive 60kHz receivers -- if you >>> live >>> in my neighborhood, I'm almost certain to be unhappy about anything you >>> deploy.) >>> >>> Note that the problem with most "atomic" clocks that I've seen is >>> actually >>> not insufficient signal (in the wee hours of the morning, when they try >>> to >>> synch). It is either excessive QRM, or orienting the clock so its >>> antenna >>> has a null toward Fort Collins. Make sure the antenna has a major lobe >>> toward Fort Collins (this may require relocating the entire clock or >>> bringing the antenna out so you can orient it independently), and that it >>> is well clear of the AC mains distribution wiring in your house and any >>> other sources of QRM (wall warts, CFL lamps, LED lamps, etc. (this may >>> also >>> require relocating the clock). >>> >>> The typical clock using a loopstick antenna has lobes to the front and >>> rear, and nulls to the sides. Thus, mounting the clock on the western >>> exterior wall (for users on the east coast) is usually best. Putting it >>> directly in front of a west-facing window may help. >>> >>> Best regards, >>> >>> Charles >>> >>> >>> ___ >>> time-nuts mailing list -- time-nuts@febo.com >>> To unsubscribe, go to https://www.febo.com/cgi-bin/m >>> ailman/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/m > ailman/listinfo/time-nuts > and follow the instructions there. > -- Intelligence has never been proof against stupidity. ___ 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] Nutty time-nuttery with WWVB
And how about that many, many "radiator" which are moving up and down with their carriers and don't give a damn about FCC Part 15 and radiating radiating day and night with substantial power, I meant that FFC approved and not approved switching mode power supplies, of which every household has a hand full of it? 73 KJ6UHN Alex On 11/10/2016 9:22 AM, William H. Fite wrote: I heartily second Charles' admonition regarding FCC PART 15 unlicensed transmissions. Part 15 explicitly states that an unlicensed operator may not cause interference with any licensed transmission. Because of the specific purpose of WWV/WWVB transmissions, any discernible leakage detectable by any other user is prima facie evidence of unlawful transmission and subject to a heavy fine. I assure you that any licensed Part 97 user who detects your emissions over the top of WWVB is quite likely to rat you out to Uncle Charlie. And should, may I say, because you will be interfering with a public service. "I am just syncing my clocks" is not going to impress the guys who appear in your driveway in a white van with RDF antennas on the roof. Sobe very damned sure that you are not radiating a discernible signal outside of the immediate vicinity of your clocks. Bill KJ4SLP On Thursday, November 10, 2016, Charles Steinmetz wrote: Peter wrote: Could I implement my own personal WWVB transmitter that would be powerful enough to be picked up by the clocks in my house? * * * Has anyone tried this? Some on the list have, and I'm sure they will provide the details. Others have mentioned the potential problems with interference to other WWVB users. For starters, make sure you study and understand Part 15 of the FCC rules before you put it on the air, or you could face a nasty enforcement action. (Even if you are Part 15-compliant, you may still screw up other users' reception and get a visit from the FCC when they complain. I operate several very sensitive 60kHz receivers -- if you live in my neighborhood, I'm almost certain to be unhappy about anything you deploy.) Note that the problem with most "atomic" clocks that I've seen is actually not insufficient signal (in the wee hours of the morning, when they try to synch). It is either excessive QRM, or orienting the clock so its antenna has a null toward Fort Collins. Make sure the antenna has a major lobe toward Fort Collins (this may require relocating the entire clock or bringing the antenna out so you can orient it independently), and that it is well clear of the AC mains distribution wiring in your house and any other sources of QRM (wall warts, CFL lamps, LED lamps, etc. (this may also require relocating the clock). The typical clock using a loopstick antenna has lobes to the front and rear, and nulls to the sides. Thus, mounting the clock on the western exterior wall (for users on the east coast) is usually best. Putting it directly in front of a west-facing window may help. Best regards, Charles ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/m ailman/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] Nutty time-nuttery with WWVB
I heartily second Charles' admonition regarding FCC PART 15 unlicensed transmissions. Part 15 explicitly states that an unlicensed operator may not cause interference with any licensed transmission. Because of the specific purpose of WWV/WWVB transmissions, any discernible leakage detectable by any other user is prima facie evidence of unlawful transmission and subject to a heavy fine. I assure you that any licensed Part 97 user who detects your emissions over the top of WWVB is quite likely to rat you out to Uncle Charlie. And should, may I say, because you will be interfering with a public service. "I am just syncing my clocks" is not going to impress the guys who appear in your driveway in a white van with RDF antennas on the roof. Sobe very damned sure that you are not radiating a discernible signal outside of the immediate vicinity of your clocks. Bill KJ4SLP On Thursday, November 10, 2016, Charles Steinmetz wrote: > Peter wrote: > > Could I implement my own personal WWVB transmitter that would >> be powerful enough to be picked up by the clocks in my house? >> * * * >> Has anyone tried this? >> > > Some on the list have, and I'm sure they will provide the details. > > Others have mentioned the potential problems with interference to other > WWVB users. For starters, make sure you study and understand Part 15 of > the FCC rules before you put it on the air, or you could face a nasty > enforcement action. (Even if you are Part 15-compliant, you may still > screw up other users' reception and get a visit from the FCC when they > complain. I operate several very sensitive 60kHz receivers -- if you live > in my neighborhood, I'm almost certain to be unhappy about anything you > deploy.) > > Note that the problem with most "atomic" clocks that I've seen is actually > not insufficient signal (in the wee hours of the morning, when they try to > synch). It is either excessive QRM, or orienting the clock so its antenna > has a null toward Fort Collins. Make sure the antenna has a major lobe > toward Fort Collins (this may require relocating the entire clock or > bringing the antenna out so you can orient it independently), and that it > is well clear of the AC mains distribution wiring in your house and any > other sources of QRM (wall warts, CFL lamps, LED lamps, etc. (this may also > require relocating the clock). > > The typical clock using a loopstick antenna has lobes to the front and > rear, and nulls to the sides. Thus, mounting the clock on the western > exterior wall (for users on the east coast) is usually best. Putting it > directly in front of a west-facing window may help. > > Best regards, > > Charles > > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/m > ailman/listinfo/time-nuts > and follow the instructions there. > -- If you gaze long into an abyss, your coffee will get cold. ___ 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] Nutty time-nuttery with WWVB
I lived till last year in Miami which is a s far away from the 60 KHz transmitter. In the 90's Junghans came to test their 60 KHz products for that reason and as long as I lived there in my concrete slab home with steel re enforcement I never had problems receiving 60 KHz on my multiple clocks, for my Lab I used a ferrite bar. Two Junghans watches with wrist band antennas also worked perfectly. Bert Kehren In a message dated 11/10/2016 11:05:25 A.M. Eastern Standard Time, csteinm...@yandex.com writes: Peter wrote: > Could I implement my own personal WWVB transmitter that would > be powerful enough to be picked up by the clocks in my house? > * * * > Has anyone tried this? Some on the list have, and I'm sure they will provide the details. Others have mentioned the potential problems with interference to other WWVB users. For starters, make sure you study and understand Part 15 of the FCC rules before you put it on the air, or you could face a nasty enforcement action. (Even if you are Part 15-compliant, you may still screw up other users' reception and get a visit from the FCC when they complain. I operate several very sensitive 60kHz receivers -- if you live in my neighborhood, I'm almost certain to be unhappy about anything you deploy.) Note that the problem with most "atomic" clocks that I've seen is actually not insufficient signal (in the wee hours of the morning, when they try to synch). It is either excessive QRM, or orienting the clock so its antenna has a null toward Fort Collins. Make sure the antenna has a major lobe toward Fort Collins (this may require relocating the entire clock or bringing the antenna out so you can orient it independently), and that it is well clear of the AC mains distribution wiring in your house and any other sources of QRM (wall warts, CFL lamps, LED lamps, etc. (this may also require relocating the clock). The typical clock using a loopstick antenna has lobes to the front and rear, and nulls to the sides. Thus, mounting the clock on the western exterior wall (for users on the east coast) is usually best. Putting it directly in front of a west-facing window may help. Best regards, Charles ___ 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] How to get PPS from ublox mini-PCI GPS to APU2 SoC serial port for ntpd
When 1PPS is implemented as a time mark signal narrow width (versus 1 Hz 50% duty cycle) and you time stamp both edges, you can always tell which is supposed to be the leading edge. Either the assert and deassert are close together in the correct case or far apart when using incorrect polarity. On Thu, Nov 10, 2016 at 10:22 AM Chris Albertson wrote: > The problem here is "real world". Yes in theory you can do it perfectly > but in the real world do all makes and models of GPS receivers get it > right? I would not bet on it. > > This is just like the argument over using NMEA only for timing. Some GPS > receivers push out NEMA sentences with very little jitter and others only > follow the NMEA spec with only requires plus or minus one second accuracy > and then there is every shade of grey between. > > My conservative engineering background tells me that unless the variation > of the pulse width is species you should assume the width is not controlled > at all. It may even look good in testing but a firmware update would kill > that. Likely in there is no regression test for not specified features. > People now days who write software (or firmware especially) will build an > automated test suit that lets them checks f the software still works after > making changes. They are careful to test each written requirement. > > The UART on the PC can interrupt on either raising or facing edges so if > the PPS is inverted you interrupt on the falling edge. But you have to > get this right too > > one IMPORTENT thing to get right is to remember that on modern control > line under RS232 the logic is "active low". TTL logic is "active high" > where a higher voltage means "one" and allow voltage means "zero" but this > is backwards for modern control under RS232 So, it is WAY-EASY to get it > wrong when connecting a TTL PPS to a modern control line. You might > need an inverter because many level shifters invert the signal > > The one thing that helps is the at 1Hz the signal is slow enough to see on > a volt meter, Even an old VTVM reacts fast enough > > On Wed, Nov 9, 2016 at 2:44 PM, Tom Van Baak wrote: > > > Bob, > > > > The PIC's I use have essentially no jitter. If they generate a 1PPS the > > edge and the pulse width are perfect, down to picoseconds. The talk about > > "other stuff" and "priority" and "number of compares" and "ambiguity" is > > worrisome. It sounds like a design or coding flaw to me, like what > happens > > when people try to do precise time with a high level language. > > > > /tvb > > > > - Original Message - > > From: "Bob Stewart" > > To: "Discussion of precise time and frequency measurement" < > > time-nuts@febo.com> > > Sent: Wednesday, November 09, 2016 9:30 AM > > Subject: Re: [time-nuts] How to get PPS from ublox mini-PCI GPS to APU2 > > SoC serial port for ntpd > > > > > > I'd like to comment on the idea of measuring the width of the pulse. My > > experience with creating the 1PPS from an interrupt is that it's fairly > > straightforward how to do the set interrupt: The interrupt happens, you > > execute one, maybe two instructions to raise the output pin, and you > leave > > the interrupt routine. But, resetting the pin is a different story. > Unless > > you've got a lot of interrupt vectors to play with, the reset part of the > > 1PPS signal is delegated to a general purpose timing interrupt where > you're > > doing a lot of other stuff - and it has a somewhat lower priority. So, > you > > wind up doing a number of compares to see if you should reset the pin, > > which adds some ambiguity to the set/reset times. > > Granted, I'm doing this on a general purpose PIC, but I have read > comments > > about various receivers having some jitter on the reset side of their > 1PPS > > pulse. > > Bob > > > > ___ > > 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. > > > > > > -- > > Chris Albertson > Redondo Beach, California > ___ > 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] Nutty time-nuttery with WWVB
> Could I implement my own personal WWVB transmitter that would > be powerful enough to be picked up by the clocks in my house? > The signal at 60 KHz might be able to be produced directly by some > sound cards. With that and a ferrite rod antenna I might get > reliable time elsewhere in my house outside of my lab. > > Has anyone tried this? > > Pete. Pete, There's lots of examples of this in the archives. It's quite easy to do. You can sometimes find someone who has done all the work for you. For example: http://unusualelectronics.co.uk/product/chronvertor-module http://unusualelectronics.co.uk/ebay/manuals/Chronvertor_User_Manual_v2.1.pdf /tvb ___ 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] How to get PPS from ublox mini-PCI GPS to APU2 SoC serial port for ntpd
The problem here is "real world". Yes in theory you can do it perfectly but in the real world do all makes and models of GPS receivers get it right? I would not bet on it. This is just like the argument over using NMEA only for timing. Some GPS receivers push out NEMA sentences with very little jitter and others only follow the NMEA spec with only requires plus or minus one second accuracy and then there is every shade of grey between. My conservative engineering background tells me that unless the variation of the pulse width is species you should assume the width is not controlled at all. It may even look good in testing but a firmware update would kill that. Likely in there is no regression test for not specified features. People now days who write software (or firmware especially) will build an automated test suit that lets them checks f the software still works after making changes. They are careful to test each written requirement. The UART on the PC can interrupt on either raising or facing edges so if the PPS is inverted you interrupt on the falling edge. But you have to get this right too one IMPORTENT thing to get right is to remember that on modern control line under RS232 the logic is "active low". TTL logic is "active high" where a higher voltage means "one" and allow voltage means "zero" but this is backwards for modern control under RS232 So, it is WAY-EASY to get it wrong when connecting a TTL PPS to a modern control line. You might need an inverter because many level shifters invert the signal The one thing that helps is the at 1Hz the signal is slow enough to see on a volt meter, Even an old VTVM reacts fast enough On Wed, Nov 9, 2016 at 2:44 PM, Tom Van Baak wrote: > Bob, > > The PIC's I use have essentially no jitter. If they generate a 1PPS the > edge and the pulse width are perfect, down to picoseconds. The talk about > "other stuff" and "priority" and "number of compares" and "ambiguity" is > worrisome. It sounds like a design or coding flaw to me, like what happens > when people try to do precise time with a high level language. > > /tvb > > - Original Message - > From: "Bob Stewart" > To: "Discussion of precise time and frequency measurement" < > time-nuts@febo.com> > Sent: Wednesday, November 09, 2016 9:30 AM > Subject: Re: [time-nuts] How to get PPS from ublox mini-PCI GPS to APU2 > SoC serial port for ntpd > > > I'd like to comment on the idea of measuring the width of the pulse. My > experience with creating the 1PPS from an interrupt is that it's fairly > straightforward how to do the set interrupt: The interrupt happens, you > execute one, maybe two instructions to raise the output pin, and you leave > the interrupt routine. But, resetting the pin is a different story. Unless > you've got a lot of interrupt vectors to play with, the reset part of the > 1PPS signal is delegated to a general purpose timing interrupt where you're > doing a lot of other stuff - and it has a somewhat lower priority. So, you > wind up doing a number of compares to see if you should reset the pin, > which adds some ambiguity to the set/reset times. > Granted, I'm doing this on a general purpose PIC, but I have read comments > about various receivers having some jitter on the reset side of their 1PPS > pulse. > Bob > > ___ > 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. > -- Chris Albertson Redondo Beach, California ___ 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] Nutty time-nuttery with WWVB
see here: http://ka7oei.blogspot.com/2013/03/getting-atomic-wwvb-clocks-to-work.html 73 KJ6UHN Alex On 11/10/2016 4:18 AM, Peter Reilley wrote: I have a few of those "atomic" clocks that receive WWVB to set the time. However since I live on the east coast they may only pick up the signal once or twice per year. Could I implement my own personal WWVB transmitter that would be powerful enough to be picked up by the clocks in my house? The signal at 60 KHz might be able to be produced directly by some sound cards. With that and a ferrite rod antenna I might get reliable time elsewhere in my house outside of my lab. Has anyone tried this? Pete. ___ 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. - No virus found in this message. Checked by AVG - www.avg.com Version: 2016.0.7859 / Virus Database: 4664/13379 - Release Date: 11/09/16 ___ 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] Nutty time-nuttery with WWVB
Found it. There was an article by Andy Flind in a UK electronics magazine, EPE December 2001 which detailed an MSF repeater to overcome a problem with 60KHz time signal reception. Shouldnt be bothered by the signal format as I remember it being a very simple design. As others have pointed out, even re radiating the original signal may cause problems so take care. On 10 Nov 2016 13:15, "Attila Kinali" wrote: > On Thu, 10 Nov 2016 07:18:42 -0500 > Peter Reilley wrote: > > > Could I implement my own personal WWVB transmitter that would > > be powerful enough to be picked up by the clocks in my house? > > The signal at 60 KHz might be able to be produced directly by some > > sound cards. With that and a ferrite rod antenna I might get > > reliable time elsewhere in my house outside of my lab. > > There are many of those. Just google for WWVB simulator. > Interestingly, there seem more DCF77 simulators out there than > WWVB ones. > > As Clint wrote, be carefull not to emit too much. Transmit only > as much power that your clocks can just barely receive it. > Which probably means not to connect any wire at all. > > 60kHz is low enough that it will pass through all but steel reinforced > concrete like through air and thus you will probably jam all sourounding > houses/clocks as well. > > The same is also true for repeaters, btw. > > Attila Kinali > > -- > It is upon moral qualities that a society is ultimately founded. All > the prosperity and technological sophistication in the world is of no > use without that foundation. > -- Miss Matheson, The Diamond Age, Neil Stephenson > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/ > mailman/listinfo/time-nuts > and follow the instructions there. > ___ 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] Nutty time-nuttery with WWVB
On Thu, 10 Nov 2016 07:18:42 -0500 Peter Reilley wrote: > Could I implement my own personal WWVB transmitter that would > be powerful enough to be picked up by the clocks in my house? > The signal at 60 KHz might be able to be produced directly by some > sound cards. With that and a ferrite rod antenna I might get > reliable time elsewhere in my house outside of my lab. There are many of those. Just google for WWVB simulator. Interestingly, there seem more DCF77 simulators out there than WWVB ones. As Clint wrote, be carefull not to emit too much. Transmit only as much power that your clocks can just barely receive it. Which probably means not to connect any wire at all. 60kHz is low enough that it will pass through all but steel reinforced concrete like through air and thus you will probably jam all sourounding houses/clocks as well. The same is also true for repeaters, btw. Attila Kinali -- It is upon moral qualities that a society is ultimately founded. All the prosperity and technological sophistication in the world is of no use without that foundation. -- Miss Matheson, The Diamond Age, Neil Stephenson ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Nutty time-nuttery with WWVB
Yes, there are projects that will generate the relevant signals but you have to be absolutely certain that the signal will not 'leak' and affect clocks you don't own. Which may not be as easy as it sounds, it's amazing just how far a couple of milli watts of RF can travel. On 10 Nov 2016 12:21, "Peter Reilley" wrote: > I have a few of those "atomic" clocks that receive WWVB to set the time. > However since I live on the east coast they may only pick up the signal > once or twice per year. > > Could I implement my own personal WWVB transmitter that would > be powerful enough to be picked up by the clocks in my house? > The signal at 60 KHz might be able to be produced directly by some > sound cards. With that and a ferrite rod antenna I might get > reliable time elsewhere in my house outside of my lab. > > Has anyone tried this? > > Pete. > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/m > ailman/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] Nutty time-nuttery with WWVB
I should also have added, it may be better to work out a repeater scheme where an externally mounted antenna re-radiates the received signal inside your home. On 10 Nov 2016 12:21, "Peter Reilley" wrote: > I have a few of those "atomic" clocks that receive WWVB to set the time. > However since I live on the east coast they may only pick up the signal > once or twice per year. > > Could I implement my own personal WWVB transmitter that would > be powerful enough to be picked up by the clocks in my house? > The signal at 60 KHz might be able to be produced directly by some > sound cards. With that and a ferrite rod antenna I might get > reliable time elsewhere in my house outside of my lab. > > Has anyone tried this? > > Pete. > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/m > ailman/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] China Oscillator Alternative
Hi Unless we are talking about something completely different …. The Z3812’s have a *lot* of information back in the archives. Just about anything you would want to know is buried in there. Just like “back then” they still are new in the box / old stock. You aren’t buying something that has sat out who knows where for who knows how long …. Bob > On Nov 10, 2016, at 4:04 AM, Gerhard Hoffmann wrote: > > Am 10.11.2016 um 07:02 schrieb Ed Armstrong: >> These have 10Mhz & 15Mhz out, which frequency is the OCXO? >> > > A 5 MHz MTI-260 > > See the text I linked to a few days ago. > > >> >> >> On 11/9/2016 7:18 PM, Perry Sandeen via time-nuts wrote: >>> List, >>> After all the problems that Bob Camp has noted with surplus OCXO's from >>> China, perhaps buying the new Lucent units on Ebay may save bad words >>> and/or unhappy actions. >>> >>> LUCENT/SYMMETRICOMKS-24361 L101, Z3812A, RFTG-U REF-0 UNIT -CASE OF 2 EACH >>> >>> $80 So for about $50 each delivered one has two brand new units that are >>> already in a chassis so with just a simple lap top computer PS one is on >>> the air. > Someone here gave a hack to use the negative output of the RS422. > That works nicely with a HAMA USB to RS232 cable. For the pinout > converter I simply cut off the cable from an old Logitech mouse. > Then half of the work is already done. Just solder the plug to > the Lucent. > > Does that mean there is new supply? I did my best to dry up > the last wave of non GPS units :-) > > regards, Gerhard > > ___ > 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] Nutty time-nuttery with WWVB
I have a few of those "atomic" clocks that receive WWVB to set the time. However since I live on the east coast they may only pick up the signal once or twice per year. Could I implement my own personal WWVB transmitter that would be powerful enough to be picked up by the clocks in my house? The signal at 60 KHz might be able to be produced directly by some sound cards. With that and a ferrite rod antenna I might get reliable time elsewhere in my house outside of my lab. Has anyone tried this? Pete. ___ 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] How to get PPS from ublox mini-PCI GPS to APU2 SoC serial port for ntpd
t...@leapsecond.com said: > The PIC's I use have essentially no jitter. If they generate a 1PPS the edge > and the pulse width are perfect, down to picoseconds. The talk about "other > stuff" and "priority" and "number of compares" and "ambiguity" is worrisome. > It sounds like a design or coding flaw to me, like what happens when people > try to do precise time with a high level language. It's fun to debug software with a scope. -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] How to get PPS from ublox mini-PCI GPS to APU2 SoC serial port for ntpd
albertson.ch...@gmail.com said: > If using the PPS for timing and the PPS is inverted you will have to measure > the delay length an account for in the config file. Or use the falling edge rather than the rising edge. Most instrumentation has a knob/button/whatever to select which direction to trigger on. If your "config file" refers to ntpd, the ATOM/PPS driver has a flag to use the falling edge. -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] China Oscillator Alternative
Am 10.11.2016 um 07:02 schrieb Ed Armstrong: These have 10Mhz & 15Mhz out, which frequency is the OCXO? A 5 MHz MTI-260 See the text I linked to a few days ago. On 11/9/2016 7:18 PM, Perry Sandeen via time-nuts wrote: List, After all the problems that Bob Camp has noted with surplus OCXO's from China, perhaps buying the new Lucent units on Ebay may save bad words and/or unhappy actions. LUCENT/SYMMETRICOMKS-24361 L101, Z3812A, RFTG-U REF-0 UNIT -CASE OF 2 EACH $80 So for about $50 each delivered one has two brand new units that are already in a chassis so with just a simple lap top computer PS one is on the air. Someone here gave a hack to use the negative output of the RS422. That works nicely with a HAMA USB to RS232 cable. For the pinout converter I simply cut off the cable from an old Logitech mouse. Then half of the work is already done. Just solder the plug to the Lucent. Does that mean there is new supply? I did my best to dry up the last wave of non GPS units :-) regards, Gerhard ___ 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] Any reference to many/all ways of measuring frequency?
drkir...@kirkbymicrowave.co.uk said: > I was looking to give a talk about frequency measurements to my amateur > radio club. Whilst I am sure that those at the club will only use a > commercial frequency counter, I thought it sensible to mention a large > number of ways, as I think that would be interesting to some. You might scan the archives looking for info on FMT - frequency measurement test. Do they play that game over there? Do the people who run the FMT give extra credit for distance from the transmitter? -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Sapphire oscillators
Hi, this project is published in the Enrico Rubiola site sice the 2008: http://rubiola.org/pdf-articles/archives/2009-arxiv-0909.3971v1-Elisa.pdf Very interesting for short and medium term stability. Cryogenic multistage expensive cooler is necessary. regards Luciano timeok From "time-nuts" time-nuts-boun...@febo.com To "Discussion of precise time and frequency measurement" time-nuts@febo.com Cc Date Thu, 10 Nov 2016 11:20:37 +1100 Subject [time-nuts] Sapphire oscillators Anyone got any comments on this? http://www.theleadsouthaustralia.com.au/industries/technology/worlds-most-precise-clock-set-for-commercial-countdown/ 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. ___ 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] Sapphire oscillators
Dear Attila You don't need a cryo-cooler, you can just use a cryostat if a break in operation (when you top up the helium) is not a problem. We operated one of the UWA CSOs like this as the flywheel for our Yb trapped ion frequency standard. A few other national standards labs use the CSOs - one for an ultra low phase noise reference, another as the flywheel in their timescale comprising fountains etc. Cheers Michael On Thu., 10 Nov. 2016 at 11:48 am, Attila Kinali wrote: > On Thu, 10 Nov 2016 11:20:37 +1100 > Jim Palfreyman wrote: > > > Anyone got any comments on this? > > > > > http://www.theleadsouthaustralia.com.au/industries/technology/worlds-most-precise-clock-set-for-commercial-countdown/ > > Cryogenic sapphire or whispering gallery mode oscillators have been around > for quite some time. You basically have a piece of sapphire (aluminium > oxide > in crystaline form)[1] in a cavity[2,3], cool everything down to liquid > helium temperatures and use this as an oscillator. There are two popular > configurations, one is to use the sapphire as resonant element like in > an LC or crystal oscillator, or more commonly, to use the sapphire as a > filter element in Pound locking scheme[4]. > > The short term stability of these oscillators is AFAIK unsurpassed > and flat up to 1000-10'000s, but exhibits drift at longer taus[5]. > > Their biggest problem is that they need a liquid helium cryo-cooler > which causes vibrations that need to be carefully filtered out. > This also makes them relatively large (fill between one and two 19" racks) > > > Attila Kinali > > [1] http://www.uliss-st.com/uploads/pics/tech2.jpg > [2] http://inspirehep.net/record/1244235/files/cavity.png > [3] http://www.uliss-st.com/uploads/media/imgmedias.jpg > [4] That's the (original) microwave variant of the Pound-Drever-Hall > locking scheme, see > https://en.wikipedia.org/wiki/Pound%E2%80%93Drever%E2%80%93Hall_technique > [5] http://inspirehep.net/record/1409150/plots > -- > Malek's Law: > Any simple idea will be worded in the most complicated way. > ___ > 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] Any reference to many/all ways of measuring frequency?
Is anyone aware of any references to review papers or other sources that describes a large number of ways of measuring the frequency of oscillators? Ideally something with lots of pretty pictures, but that's not essential. Ideally something that covers various techniques from 50 Hz to light. Unfortunately I have lost access to the university source I once had that allowed downloads of almost any scientific paper. So if you have something that's not easy to download, please email it to me. I was looking to give a talk about frequency measurements to my amateur radio club. Whilst I am sure that those at the club will only use a commercial frequency counter, I thought it sensible to mention a large number of ways, as I think that would be interesting to some. I am not well qualified to do such a talk, but I know more than any others at my club on this matter. If anyone who feels that they could give a good talk on the subject to a radio club in Essex, please contact me off list. At least some of it would need to be understandable to those without a great electronics knowledge. A talk suitable for a scientific conference on the topic would not be useful. We can pay reasonable travelling expenses. Dr David Kirkby Managing Director Kirkby Microwave Ltd Registered office: Stokes Hall Lodge, Burnham Rd, Chelmsford, Essex, CM3 6DT, United Kingdom Registered in England and Wales as company number 08914892 http://www.kirkbymicrowave.co.uk/ Tel 07910 441670 / +44 7910 441670 (0900-2100 GMT) ___ 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.
