[time-nuts] Re: GPS failed
On 7/11/22 12:48, jeanmichel.friedt--- via time-nuts wrote: for what it's worth ... the UK gov. is nice enough to warn about GPS jamming exercises https://www.ofcom.org.uk/spectrum/information/gps-jamming-exercises not sure about the US of A announcements on such activities. At least in France I have never seen such warnings. Yes, they do. Still, it is annoying to be piloting an aircraft in instrument conditions and have GPS go away. When it has happened usually I am prepared to switch back to VOR navigation. --  <https://www.lloyd.aero> Brian Lloyd 706 Flightline Spring Branch, TX 78070 br...@lloyd.aero <mailto://br...@lloyd.aero> +1.210.620.0011 ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe send an email to time-nuts-le...@lists.febo.com
Re: [time-nuts] Leakage, tinySA
On 1/16/21 04:32, Hal Murray wrote: The 10 MHz is stronger near coax carrying 10 MHz and next to a Z3801A. I'll have to try some good cables. Anybody have a favorite source? Is there a magic word? Do I have to specify the type of coax? Yes. RG400 or RG316. Do NOT use RG58 or RG174. Both RG400 and RG316 are double-shielded to reduce leakage. The choice is dictated by length of run and physical flexibility required. Mostly I use RG316 cables on the bench. For more than a meter or so I go with RG400. You can get either type of cable terminated with N, BNC, TNC, or SMA connectors. All kinds of pre-made cable assemblies using RG316 are available from Amazon for surprisingly-low prices. I can't buy the coax and connectors for what I end up paying Amazon for completed cables. For RG400 I end up making my own cable assemblies. The LMR cables (Times Microwave and knock-offs) are pretty good too. LMR195 is pretty good but not nearly as flexible as the aforementioned cables. LMR400 is just too big and inflexible for easy use on the bench. --  <https://www.lloyd.aero> Brian Lloyd 706 Flightline Spring Branch, TX 78070 br...@lloyd.aero <mailto://br...@lloyd.aero> +1.210.802.8359 ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] On choosing reasonable synthesizer PN requirements
On Fri, Apr 24, 2020 at 8:08 AM jimlux wrote: > On 4/24/20 5:52 AM, David J Taylor via time-nuts wrote: > > Hi > > > > The “wiggles” he is chasing are about 2-3 Hz (by eyeball on his charts). > > At 2.4 GHz, > > that is a fairly convenient ~1 ppb. The Z-3801 (if it was in good > > health) should be easily > > able to hold that level of performance. It’s not clear which MD-011 he > > is using, but it is > > a pretty good bet it will also hold that level as well. The usual > > disclaimers about good > > satellite view for the GPSDO’s would of course apply. > > > > Substituting a typical telecom Rb for either device would likely also > > allow the wiggles > > to be observed (or not). That would take out the whole dependence on GPS. > > > > (Yes I realize those comments are probably better directed to those > > involved ….). > > > > Bob > > > It's a fascinating writeup - the author does time-nut like stuff at > work, so he looked at the possibilities - is the GPSDO at Bochum > screwing up (can't actually get in because of COVID-19) - so he compares > with a locally generated uplink. > He also compares with the signal from an uplink from Mauritius, so the > Doppler is slightly different. > > I'm going to guess just what he said at the end - some sort of thermal > thing on the spacecraft. > And I would guess the battery charging system. I would love to see the bus voltage plot superimposed on the The "wiggles". (Is the housekeeping telemetry decodable?) Notice that the frequency "pop" in the beacon coincides with the end of the "wiggles". I haven't looked but does the bird have a planar PV array? If so, I am guessing that this is when the charging system shuts down as the PV array stops producing output and then shortly thereafter something else turns off or turns on, the two events creating the leading and trailing edges of the "pop". If it has a max PPT charging system (of course it does) I can imagine, as the output of the array falls off, the MPPT algorithm "hunting" to find an optimum operating point and causing bus voltage to vary. Of course, it could always be the Radar Men from the Moon. -- Brian Lloyd 706 Flightline Spring Branch, TX 78070 br...@lloyd.aero +1.210.802-8FLY (1.210.802-8359) ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] GPS module recommendation for Pi timing
On Sat, Mar 14, 2020 at 12:52 PM Bob kb8tq wrote: > > I understand completely. Still, I have to come up with a > reasonably-priced > > source of time and it does seem like GPS is the right answer. I can live > > with units going off-line periodically due to insufficient timing > accuracy, > > but I cannot have them drifting away from correct time. > > Only you can evaluate how important this or that aspect of the design is. > If *any* timing drift past 1 ms becomes an issue, some sort of TCXO based > GPSDO may be the real answer. > In reading the data sheet for the LEA-M8T it does have a TCXO for the timing outputs. > With a bare crystal, you could easily have a 10’s of ppm sort of error. If > you do, then any outage over about 100 seconds will hit your limit. > Yes, and I just need to know that I am out-of-spec so I can turn off participation by that device until it has good timing again. And if I have to end up disciplining a local TCXO then I can do that too, and then I use a cheaper GPS module. Ah, design decisions. Where would we engineers be if we weren't making design decisions compromises. ;-) > > The signal will be squared and used as a clock for something else. > > Duty-cycle is flexible. As long as the rising edge is clean and there > isn't > > too much jitter, I can live with it. I have no erroneous notion that I am > > getting a clean sine wave or a symmetrical square wave. Also, this is in > > the "nice to have" category and I can do away with it and use a GPS > module > > that only has 1pps. > > The output will have jitter at the same level as the time pulse. If it’s a > 20 ns > time pulse pre-sawtooth, then the 10 MHz will also hop by 20 ns. > Yes, so what happens depends on whether it is phase error or phase jitter, and then what the device wanting the 10MHz reference does with it. Since that is part of this that I don't have control over, I am going to have to get more information. But if that other time-pulse can be used as a 10MHz reference that is used to discipline another oscillator rather than being used directly, it should be OK. I just need more information on this part of it. I just don't know how clean that output from the Ublox is. > > > > > So I am still hoping that someone will say, "The U-Blox LEA-M8T is a > pretty > > good choice but for what you are talking about, you might want to look at > > the XYZ module as well." > > There are maybe another two dozen modules out there that might work and > cost the same or less. Buying a few of this and that / trying them out is > about > the only way to know if they are “good enough” for all the details of your > application. > > The bigger issue is - how much can you invest to dig through a pile of > modules? > The simple answer is indeed to just pick one and accept the cost impact. > That is indeed the question. Given the experience level here I was hoping that others had run into similar issues and might have more information to share with me, or even point me to something that would works as well or better than the Ublox. Thanks! I appreciate your input. -- Brian Lloyd 706 Flightline Spring Branch, TX 78070 br...@lloyd.aero +1.210.802-8FLY (1.210.802-8359) ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] GPS module recommendation for Pi timing
On Sat, Mar 14, 2020 at 10:57 AM Bob kb8tq wrote: > Hi > > > > On Mar 14, 2020, at 10:54 AM, Brian Lloyd wrote: > > > > On Fri, Mar 13, 2020 at 8:49 PM Bob kb8tq wrote: > > > >> Hi > >> > >> If you always operate in fixed locations, your chances of seeing a slip > >> are not that high. The original post question and reference here were to > >> timing in a *mobile* situation. > >> > > > > Thank you all for your inputs. Here is a little more data, prompted by > > comments and questions. (Some of this I wasn't thinking about at first.) > > > > I realized that, while I expect the majority of units to be stationary > with > > the ability to properly position an antenna, there is a chance that one > or > > more of the units may be mobile. Regardless of mobility, the purpose will > > be time and frequency reference, not position. Does that change my choice > > of device? > > In order to get time, you first need location. Without location, there is > no > way to correct for the time of flight of the signals. > I understand. The question is, are the timing-oriented GPS modules going to work in that application or should I opt for a position-oriented GPS and accept lower accuracy of 1pps? In a mobile situation, timing can be tough. At some point a ZED-F9P or a > member of that family would do better if highly accurate mobile time is > the > goal. Since your needs are modest, it may not be worth the cost. > And that is the question. There is still the issue of going under a bridge / into a “canyon” and > having the GPS stop due to lack of signal. This sort of dropout can > easily run into the “couple of minutes” range. > Let me put it this way, if I am going under a bridge or in a tunnel, the point will be moot. “Good antenna location” in this case is often not an easy thing to do. > Ideally you want a full sky view down to 10 or 20 degrees above the > horizon. Your typical “fast setup” location usually does not do this. With > an “impaired” antenna location, you can get dropouts based on the > limited amount of sky you can get at. > I understand completely. Still, I have to come up with a reasonably-priced source of time and it does seem like GPS is the right answer. I can live with units going off-line periodically due to insufficient timing accuracy, but I cannot have them drifting away from correct time. > > Some of the units may have access to the Internet and I could run NTP on > > them but the majority will be using GPS as the single stand-alone source > of > > UTC. The goal is for all the units to be sync'd to UTC as they need to > > perform repetitive functions concurrently. > > > > The starting point for me was going to be the Ublox LEA-M8T because it is > > current generation and Ublox offers a common footprint so that, if > > production runs into the future, there will be newer modules that can be > > dropped onto the same board. I want the second output to use as a 10MHz > > reference. I have need for a 3e-7 accuracy 10MHz frequency reference in > > some cases and that looked like it would do what is needed without going > > full-on GPSDOCXO. > > > > So is my first choice of the Ublox LEA-M8T a good one or should I be > > looking at other units. While I don't want to spend $50(us) on a > receiver, > > if it does the best job, it will fit the budget and that extra timing > > output I can use to generate 10MHz is quite attractive. > > That output is likely to be very “dirty” as far as spurs and noise are > concerned. > If you have any significant spectral purity needs … yikes. > The signal will be squared and used as a clock for something else. Duty-cycle is flexible. As long as the rising edge is clean and there isn't too much jitter, I can live with it. I have no erroneous notion that I am getting a clean sine wave or a symmetrical square wave. Also, this is in the "nice to have" category and I can do away with it and use a GPS module that only has 1pps. So I am still hoping that someone will say, "The U-Blox LEA-M8T is a pretty good choice but for what you are talking about, you might want to look at the XYZ module as well." -- Brian Lloyd 706 Flightline Spring Branch, TX 78070 br...@lloyd.aero +1.210.802-8FLY (1.210.802-8359) ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] GPS module recommendation for Pi timing
On Fri, Mar 13, 2020 at 8:49 PM Bob kb8tq wrote: > Hi > > If you always operate in fixed locations, your chances of seeing a slip > are not that high. The original post question and reference here were to > timing in a *mobile* situation. > Thank you all for your inputs. Here is a little more data, prompted by comments and questions. (Some of this I wasn't thinking about at first.) I realized that, while I expect the majority of units to be stationary with the ability to properly position an antenna, there is a chance that one or more of the units may be mobile. Regardless of mobility, the purpose will be time and frequency reference, not position. Does that change my choice of device? Some of the units may have access to the Internet and I could run NTP on them but the majority will be using GPS as the single stand-alone source of UTC. The goal is for all the units to be sync'd to UTC as they need to perform repetitive functions concurrently. The starting point for me was going to be the Ublox LEA-M8T because it is current generation and Ublox offers a common footprint so that, if production runs into the future, there will be newer modules that can be dropped onto the same board. I want the second output to use as a 10MHz reference. I have need for a 3e-7 accuracy 10MHz frequency reference in some cases and that looked like it would do what is needed without going full-on GPSDOCXO. So is my first choice of the Ublox LEA-M8T a good one or should I be looking at other units. While I don't want to spend $50(us) on a receiver, if it does the best job, it will fit the budget and that extra timing output I can use to generate 10MHz is quite attractive. -- Brian Lloyd 706 Flightline Spring Branch, TX 78070 br...@lloyd.aero +1.210.802-8FLY (1.210.802-8359) ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] GPS module recommendation for Pi timing
On Fri, Mar 13, 2020 at 9:59 AM Peter Membrey wrote: > Hi Brian, > > We published this back in 2016 but it provides an analysis on the > stability of the STC on the first three generations of Raspberry Pi as well > as the stability profile of the uBlox M8Q: > > https://crin.eng.uts.edu.au/~darryl/Publications/Pi-hat_current.pdf Thank you. Perfect. Reading now. Bob KB8TQ: We are laying out our own board as it will be doing other things besides GPS time/frequency keeping. Trying to avoid the use of USB. 1pps will go directly to a GPIO pin, assuming that will provide the best performance. Hal Murray: Yes, I am trying to discipline the system clock. Arne: Yes, I was considering using gpsd. Right now I am leaning toward the Ublox LEA-M8T. I have a use for the other programmable output from the Ublox. -- Brian Lloyd 706 Flightline Spring Branch, TX 78070 br...@lloyd.aero +1.210.802-8FLY (1.210.802-8359) ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] GPS module recommendation for Pi timing
On Fri, Mar 13, 2020 at 9:20 AM Jim Harman wrote: > Is this application for a product that you will be selling in quantity and > producing over time, or a one-off or low volume application? > It will have a run of at least 100 units, maybe more. I would like it to have a decent lifetime in case we need to make more. > On Fri, Mar 13, 2020 at 10:07 AM Brian Lloyd wrote: > > > I have an application where I need to synchronize the internal TOD RTC > in a > > raspberry pi and need to pick a GPS module. We are building our own > > hardware but still using the Pi so interconnection will be via > GPIO/serial. > > We won't try to use USB. > > > > This is not an NTP application. These units will be in the field and will > > most likely not have Internet access. I need their clocks to be pretty > > close. I am shooting for 1ms ... if possible. > > > > The new M9F and M9T modules from Ublox are a bit pricey. The M8T is a bit > > more reasonable. OTOH I realize there are limits to how tightly I can > > control the Pi's RTC and will run into diminishing returns, so even the > M8T > > might be overkill. > > > > Has anyone here figured out what the reasonable limit is for timing on a > > Pi, and what makes sense for a timing module for an application like > this? > > -- Brian Lloyd 706 Flightline Spring Branch, TX 78070 br...@lloyd.aero +1.210.802-8FLY (1.210.802-8359) ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
[time-nuts] GPS module recommendation for Pi timing
I have an application where I need to synchronize the internal TOD RTC in a raspberry pi and need to pick a GPS module. We are building our own hardware but still using the Pi so interconnection will be via GPIO/serial. We won't try to use USB. This is not an NTP application. These units will be in the field and will most likely not have Internet access. I need their clocks to be pretty close. I am shooting for 1ms ... if possible. The new M9F and M9T modules from Ublox are a bit pricey. The M8T is a bit more reasonable. OTOH I realize there are limits to how tightly I can control the Pi's RTC and will run into diminishing returns, so even the M8T might be overkill. Has anyone here figured out what the reasonable limit is for timing on a Pi, and what makes sense for a timing module for an application like this? Thanks. -- Brian Lloyd 706 Flightline Spring Branch, TX 78070 br...@lloyd.aero +1.210.802-8FLY (1.210.802-8359) ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Chinese NTP Server Part 2
On Wed, Mar 4, 2020 at 10:26 PM xaos wrote: > Hello everyone, > > So, the first Box I got was missing 2 parts. Namely the Voltage > regulator and output driver. > However, the OCXO was there. Weird... > Yes and no. Yes, there is an OCXO there but its output is square wave, not sine wave. If you get the version that has the 10MHz output, they change out the OCXO for one that has sine output ... and charge an extra $150. In my case, I didn't care. Everything I have that uses a 10MHz reference ends up squaring the signal anyway. So I just got the isolated switching regulator and found a usable op-amp to use as a buffer. > I got in touch with them and they seemed very nice. They sent me a new > box and I've been running it for a few weeks. > > Brian Lloyd added the 2 parts to his unit and he was able to get a > decent output wave. The weird thing is > that his post might have been read by these guys, as the driver on my > unit is actually sanded down (yes I said sanded!) > so as to not show the part number ! > Ha! Ah, yours has a sine output! > Here are some pics: > > https://www.maximaphysics.com/GPS.shtml > > > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > I spent some time measuring the frequency accuracy and the accuracy of the 1pps compared to my T-bolt. The NTP server 1pps always leads the T-bolt by anywhere from 20ns to over 80ns. I would not plan to use this for any sort of accurate timekeeping, unless it was just something like a human clock ... or maybe an NTP server. ;-) -- Brian Lloyd 706 Flightline Spring Branch, TX 78070 br...@lloyd.aero +1.210.802-8FLY (1.210.802-8359) ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Are there SC-crystals out there in the wild that are not Overtone?
On 2/27/20 10:45, Richard (Rick) Karlquist wrote: > OTOH, you could build a simple Colpitts > oscillator and see where it oscillates. > That's what they did back in the dark > ages. > > Any time nut should be up for that. I was going to suggest pumping it with white noise and then doing a long FFT to see which bin has any energy in it to get into the ballpark but building an oscillator seems to be far and away the simplest solution. > > Rick N6RK > > On 2/27/2020 5:35 AM, Bob kb8tq wrote: >> Hi >> >> Ok, so just to run the math: >> >> 5 MHz / 2.9 = 1.724 MHz >> >> If the Q at the fundamental is 500K (a wild guess) then 1.724 MHz / >> 500,000 = 3.4 Hz >> >> In a world where a synthesized sweeper *might* be stepping in 10Hz >> steps, that’s an >> easy one to miss. >> >> Bob >> >> >>> On Feb 26, 2020, at 11:40 PM, Bernd Neubig wrote: >>> >>> Hi Gerhard, >>> I am rather sure that it is a 5 MHz 3rd overtone crystal. >>> the resistance should be in the 80 to 110 Ohm range and Q about 1.5 >>> million. You can see the resonance without ringing in a span of 100 >>> Hz or smaller with a sweep time of 10 sec minimum. >>> See attached the response of a 5 MHz SC3 crystal in HC-40/U package. >>> Indeed the 5.45 MHz is the B-mode which has a temperature >>> coefficient of -30 ppm/K >>> Because the crystal blank has a plano-convex shape. The overtones >>> are quite far away from 3 times or 5 times the fundamental mode. 3rd >>> overtone is about (rough guess) 2.9 time of fundamental mode. >>> To find them you must really carefully sweep around a few 10 to 100 >>> kHz span with slow sweep time a narrow bandwidth >>> >>> Regards >>> Bernd >>> DK1AG >>> >>> -Ursprüngliche Nachricht- >>> Von: time-nuts [mailto:time-nuts-boun...@lists.febo.com] Im Auftrag >>> von Gerhard Hoffmann via time-nuts >>> Gesendet: Mittwoch, 26. Februar 2020 01:42 >>> >>> To get a first impression, I soldered the crystal to an SMA plug and >>> put it on an >>> R ZVB-8 network analyzer and measured S11. I could see the 5 MHz >>> resonance >>> as a 15 dB dip. There was also a resonance at 5.45 and a smaller >>> one another 90 KHz >>> higher. the +10% suggest that it is an SC cut. >>> But I could not see anything at 1 or 1. MHz, so it should be a >>> fundamental crystal? >>> Is that common? >>> I made most measurements at room temperature. I can turn the hot air >>> solder >>> station down to 91°C which is not far away from the crystal's 87.7°C >>> inflection point, and I could see some variation on the 5.45 MHz >>> resonance vs. temp. >>> I must build a fixture for the hot air because the sweep time at 1 >>> Hz bandwidth >>> is close to eternal. >>> Is the un-harmonicity (???) between fundamental and overtones >>> stronger with SC-cuts >>> than normal AT? I also could not see anything at 15 MHz. Next I'll >>> make a board >>> for the PI fixture as described by Bernd Neubig in his crystal >>> cookbook. >>> BTW I could see some more dips with >= 10 Hz resolution. I hope that >>> does not mean >>> that the ZVB needs service. >>> >>> >>> >>> >>> ___ >>> time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, >>> go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >>> and follow the instructions there. >>> <5MC5735H.jpg>___ >>> time-nuts mailing list -- time-nuts@lists.febo.com >>> To unsubscribe, go to >>> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >>> and follow the instructions there. >> >> >> ___ >> time-nuts mailing list -- time-nuts@lists.febo.com >> To unsubscribe, go to >> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >> and follow the instructions there. >> > > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. --  <https://www.lloyd.aero> Brian Lloyd 706 Flightline Spring Branch, TX 78070 br...@lloyd.aero <mailto://br...@lloyd.aero> +1.210.802.8359 ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Fake new LPRO 101 Rb's on Ebay?
On 2/4/20 01:29, Perry Sandeen via time-nuts wrote: > Yo Bubba Dudes!, > There are two vendors on Ebay selling *new* LPRO 101 Rb's for around $160 > each, with discounts for larger purchases. The general price of a used LPRO > seems to be in the $250 to $350 range. Anybody have any ideas? (Discount > for coronavirus?) > In all seriousness, can the coronavirus be transmitted in gear we buy from > China or does it require a living host for spreading? OK, coronavirus fun aside, is it possible that these LPRO-101's that are listed as new may be new old stock, i.e. could they have been backup units in a box that never got put into service? That would suggest that they have full life available on the Rb lamp. --  <https://www.lloyd.aero> Brian Lloyd 706 Flightline Spring Branch, TX 78070 br...@lloyd.aero <mailto://br...@lloyd.aero> +1.210.802.8359 ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
[time-nuts] Thunderbolt power requirements
I am in the process of getting my "time box" finished. It has three frequency/time references: a T-bolt, an LPRO-101, and the Chinese NTP/10MHz server. Distribution of 10MHz and 1pps is via a TADD-1 and TADD-3 respectively. I have a Microsemi 58536A distribution amp for GPS. (I do have one other full-time consumer of GPS and one other part-time consumer of GPS.) I would like everything to run from a +12VDC supply to facilitate avoiding power outages. The LPRO-101 is powered by a 12V-to-24V switcher followed by a brute-force LC filter to clean up the PSU noise, so it is effectively happy with anything from 9-16V. My main +12V supply bus is a 100AH gel-cell that is being float charged at about 13.2V but may be up to +14V during charge and down to +11V during discharge. I want to run everything from this bus. No problem for the Chinese NTP server, the TADD's, or the LPRO-101 with its upconverter. The wild-card in all this is the power for the T-bolt. It needs +5, +12, and -12. I currently am powering it from the mains using a 3-output supply. That doesn't allow for conveniently running from battery power. Obviously the +5 needs to be pretty tightly regulated but not sure about the +12 and -12. Can I cheat and run the +12 from my 12V power bus or does it need to be more tightly regulated? If necessary, I can boost to +15 and then regulate down to +12. I suspect the primary use for +12V is the oven. If the oven controller is analog using something like a FET or BJT as the control element for the heater, supply voltage should be pretty much a non-issue as these devices have a constant current for a given base/gate drive, thus pretty well decoupling the heater current from the supply voltage. Of course I can derive -12V using an isolated switching module. Anyone know the -12V current requirement of the T-bolt off their heads? (Yes, I know, I can take everything apart and stick an ammeter in series with each leg but if someone knows, I can avoid having to do that. Yes, I am being lazy.) Thanks in advance. -- Brian Lloyd 706 Flightline Spring Branch, TX 78070 br...@lloyd.aero +1.210.802-8FLY (1.210.802-8359) ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Simple GPSDO Multiple Outputs - buffered line driver options?
On 1/21/20 03:19, skipp isaham via time-nuts wrote: > Hello once again to the Group, > > May I ask what the current relatively simple options are for > expanding a Thunderbolt or equivalent... output for distribution > to multiple devices? TAPR TADD-3 for 1pps distribution. https://tapr.org/?product=tadd-3-pulse-per-second-distribution-amplifier TAPR TADD-1 for 10MHz distribution https://tapr.org/?product=tadd-1-rf-distribution-amplifier There are better solutions but these have a good cost:performance ratio. --  <https://www.lloyd.aero> Brian Lloyd 706 Flightline Spring Branch, TX 78070 br...@lloyd.aero <mailto://br...@lloyd.aero> +1.210.802.8359 ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] thunerbolt, 2 problems
On Thu, Jan 16, 2020 at 9:20 PM Bill Beam wrote: > Brian, > LH can do this. Issue the command "p" to bring up the PPS control menu. > Thank you. LH does so much but finding the right command is a challenge. I did finally find a copy of tboltmon.exe. That and LH both report that 1pps is turned on. Nothing coming out. The Tbolt is locked and 10MHz is within range when compared with my other GPSDOs and my Rb. So it appears that the 1pps has failed. It appears that the 74AC04 is being used as a buffer to drive the output. I am seeing no pulse on the inputs or outputs of that chip so the 1pps is lost somewhere else. Does anyone have a schematic that I can use to trace back the 1pps? > On Thu, 16 Jan 2020 20:44:43 -0600, Brian Lloyd wrote: > > >After quite some time I dragged out my Tbolt and fired it up. Comes up > >OK. Lady Heather is happy. 10MHz is spot on (after an hour or so). > >Problem is, 1pps is missing. 1pps is enabled (or appears to be). > >Suggestions? > > >I am running Trimble Visual Timing Studio 2.03.12. It seems to know > >about the Thunderbolt-E but not the original thunderbolt. Not sure it > >will do the right thing. Does anyone have an older copy of the program > >for configuring the T-bolt? > > >Thanks in advance. > > >-- > > > >n++ <https://www.lloyd.aero> > > >Brian Lloyd > >706 Flightline > >Spring Branch, TX 78070 > >br...@lloyd.aero <mailto://br...@lloyd.aero> > >+1.210.802.8359 > > > >___ > >time-nuts mailing list -- time-nuts@lists.febo.com > >To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > >and follow the instructions there. > > > Bill Beam > NL7F > > > > > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > -- Brian Lloyd 706 Flightline Spring Branch, TX 78070 br...@lloyd.aero +1.210.802-8FLY (1.210.802-8359) ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
[time-nuts] thunerbolt, 2 problems
After quite some time I dragged out my Tbolt and fired it up. Comes up OK. Lady Heather is happy. 10MHz is spot on (after an hour or so). Problem is, 1pps is missing. 1pps is enabled (or appears to be). Suggestions? I am running Trimble Visual Timing Studio 2.03.12. It seems to know about the Thunderbolt-E but not the original thunderbolt. Not sure it will do the right thing. Does anyone have an older copy of the program for configuring the T-bolt? Thanks in advance. --  <https://www.lloyd.aero> Brian Lloyd 706 Flightline Spring Branch, TX 78070 br...@lloyd.aero <mailto://br...@lloyd.aero> +1.210.802.8359 ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Chinese NTP Time server
OK, I tried the AD8055A op-amp in the buffer. Output now looks exactly like the output of the OCXO (square wave). Unloaded output is 3.2Vpp. Output into 50 ohms is +10dBm, nice and clean. So, if you buy one and want to add the components to get 10MHz sq-wave output, you need to add a TBA 1-1219 isolated DC/DC converter, and an AD8055A op-amp. Works great. Mouser has them in stock. While I do have hot-air SMD-rework capability, the SOIC-8 package was easy to hand-solder with a small tip on my Hakko solder station so I didn't have to go get solder paste. BTW, the price quoted for a unit WITH 10MHz output was $350, substantially more than the $201 for the non-10MHz unit. For $10 in parts I am happy. OK, it isn't sine-wave output. I don't have anything that requires a sine wave reference. So this meets my needs for NTP stratum-1 for the machines in my house, and 10MHz for my radios. Still, I wish to graduate to full time-nuttery status. I would like to do the ADEV analysis. Other references I have kicking around: Thunderbolt, Leo Bodenar GPSDO, Ephratom LPRO-101 Rb. Unfortunately I don't have a good, free-running OCXO for short-term comparison. Still, I suspect the Rb should work well enough for that. Also, the only device I have to DO the comparison is a Fluke T7260a. Thinking about a TICC. Advice? Brian, WB5BL --  <https://www.lloyd.aero> Brian Lloyd 706 Flightline Spring Branch, TX 78070 br...@lloyd.aero <mailto://br...@lloyd.aero> +1.210.802.8359 ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Chinese NTP Time server
On Fri, Dec 27, 2019 at 2:24 AM xaos wrote: > Brian, > > I created a new web page with some pics and a live output of the NTP > server from "Lady Heather V5.0" > Nice. Did you interface LH using the serial output or through a network connection? I haven't run LH in about 6-7 years so I don't know its current feature set. I haven't made a cable for the HD-15 connector. > https://www.maximaphysics.com/GPS.shtml > > You can clearly see the Missing OP-AMP on the bottom of the unit in the > pic. > You would think that these guys would add a penny part to this ... > Well, the parts came to around $10(us) from Mouser but I get your point. They should be here today so I should be able to give you more info tonight. > > The guy I bought it from has already agreed to have me sent it back. > However, If you get yours working I don't want to bother. Also, I wonder > of my OCXO from a HP counter > would fit in there. Prob needs lots of work. > The OCXO is powered by the +12V supply after passing through the input filter. The wall-wart switcher they provide is quite noisy, as one would expect of a cheap wall-wart switcher. (Ripple and noise measuring about 60mV p-p with ripple and switching transients clearly visible.) Measuring the noise at the input to the OCXO the noise is down to about 15mV, mostly just HF noise, around 50-60MHz my 'scope says. Switching transients and ripple are gone. So it appears to me that they did spend some effort trying to quiet down the noise at the power input. And here I was worried what my next crazy project would be. > Heh. > George, N2FGX > > On 12/22/2019 12:49, Brian Lloyd wrote: > > > > On 11/26/19 09:28, x...@darksmile.net wrote: > >> Hello everyone, > >> > >> Does anyone here know about this item: > >> > >> > https://www.ebay.com/itm/Brand-New-NTP-Time-Server-GPSDO-GPS-Disciplined-Oscillator-GPS-Clock/362758051388?hash=item547610963c:g:yFIAAOSwgztdgfM9 > >> > >> > >> George, N2FGX > > OK, I ordered one. I missed the part about the 10MHz output being > > "optional". (Optional? Really?) So I ordered one and it arrived 2 days > > ago. Delivery took about 3 weeks. Looks nice, well packed, no damage. It > > includes an active GPS antenna with about 20' of RG174 and a 12VDC > > wall-wart. Unit, antenna, and PSU, nothing else. No doc and no software. > > No problem ... so far. > > > > Plugged it in. Power supply LED comes on and the Sync LED is flashing at > > about 2Hz. About 20 seconds later the SV LED comes on. about 2 minutes > > later the Sync switches to 1Hz. I am guessing it has achieved some sort > > of lock. I connect the 10MHz output to my FA-2. Of course, no 10MHz > > output. (More on this later.) I plugged it into the network. Looked at > > my DHCP server. No IP address assigned. Huh. How do I find this thing on > > my network? > > > > eBay message back to the seller. Seller sends me a link to a zip file > > with the software and doc. The first 'uh oh' is that all the file names > > are in mandarin. I must admit, I find .pdf and .exe > > amusing. I have an old laptop that dual-boots Linux and Windows just for > > this sort of thing, i.e. annoying software that only runs on Windows. I > > extract everything from the zip file and try things out. One of the > > programs shows just an ip address of 192.168.0.100 and has three windows > > separated into dotted-quads. Could this be the tool that sets the IP > > address, subnet mask, and gateway? I run the PDF that opens with a > > picture of the unit through google translate. OK, yes, that is what the > > program does. There is a picture of the window and, guessing at the > > examples, I was right, IP addr, mask, and gateway. With 5 buttons to > > click on in varying orders, it tooks me several tries to finally get it > > to change its IP address to one on my network. It is now pingable. > > > > I look at some of the other programs. These are mostly in English, being > > open software, and do things like let you look at the status of the GPS > > receiver. After successfully setting the IP address of the unit, I was > > able to run the utility 'PowerGPS.exe' and have it report GPS status > > from the box. > > > > So I pointed ntp on my linux server at the box as a server. It synced > > right up and chose it as the primary ntp source. Clearly it works just > > peachy as an NTP server and is running in my network that way. Now to > > tackle the lack of 10MHz output. > > > > Opening up the box it clearly has a 10MHz OCXO so getting something out > > the 10MHz BNC connector should be fairly stra
Re: [time-nuts] Chinese NTP Time server
On 12/22/19 17:16, Adrian Godwin wrote: > Voltage converter might be one of these : > > https://www.we-online.com/catalog/datasheet/177920521.pdf > > You can also sometimes find a similar device on an old 10baseT ethernet > card, where it generates a -9V supply. That is definitely on the right track. I need 7.5V out (if it tracked the input that would be perfect) and the pinout is different, i.e. the NTP server has a pinout of gnd, in, out, gnd, respectively. But you definitely found something in the ballpark. Thanks! --  <https://www.lloyd.aero> Brian Lloyd 706 Flightline Spring Branch, TX 78070 br...@lloyd.aero <mailto://br...@lloyd.aero> +1.210.802.8359 ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Chinese NTP Time server
On Mon, Dec 23, 2019 at 9:42 AM Brian Lloyd wrote: > > > On 12/22/19 17:16, Adrian Godwin wrote: > > Voltage converter might be one of these : > > > > https://www.we-online.com/catalog/datasheet/177920521.pdf > > > > You can also sometimes find a similar device on an old 10baseT ethernet > > card, where it generates a -9V supply. > That is definitely on the right track. I need 7.5V out (if it tracked > the input that would be perfect) and the pinout is different, i.e. the > NTP server has a pinout of gnd, in, out, gnd, respectively. > > But you definitely found something in the ballpark. Thanks! > Ha! Found it! It is the Traco TBA1-1219, isolated DC/DC converter. The floating output can have the + side connected to ground to make a negative supply. Turns out the input is just the raw 12VDC input and -9V output should be more than enough for the 79L05 to regulate down to -5V for the negative rail on the op-amp. I couldn't find it earlier because I was looking under 'inverting regulator' instead of 'isolated DC/DC converter'. You put me on the right track. Parts ordered from Mouser. I went with the LT1227 op-amp for the buffer. I'll post how it works when I get it all together. -- Brian Lloyd 706 Flightline Spring Branch, TX 78070 br...@lloyd.aero +1.210.802-8FLY (1.210.802-8359) ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Chinese NTP Time server
o manage to make this work anyway. Hmm ... if I DC couple the input and run the op-amp with a single-ended +5v supply, it might work without the negative supply at all. My only worry would be latch-up because the input would be going right to the negative rail and approaching within 1.5V of the positive rail. OTOH, most op-amps now are pretty immune to latch-up. Just thinking aloud here. I am sure someone here has some ideas about getting this to work. Thanks in advance for humoring me. --  <https://www.lloyd.aero> Brian Lloyd 706 Flightline Spring Branch, TX 78070 br...@lloyd.aero <mailto://br...@lloyd.aero> +1.210.802.8359 ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Spark timer.
On Sat, Nov 23, 2019 at 11:47 PM paul swed wrote: > ... > If I had seen the item you picked I will bet I would have been clueless to > what it was. He has odd things after all. > Enjoy. > Regards > Paul > WB8TSL > I used one back in the dim, dark, recesses of the past. A strip of lightweight paper could be drawn through the device and the spark would puncture the paper at even time intervals. The paper is then attached to the mass being accelerated and provides a means of measuring displacement vs. time. Used a lot in lower level physics labs when teaching laws of motion. Now we just have fast cameras or direct measurement of acceleration and velocity. -- Brian Lloyd 706 Flightline Spring Branch, TX 78070 br...@lloyd.aero +1.210.802-8FLY (1.210.802-8359) ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Talking Clock
On Tue, Oct 1, 2019 at 3:00 AM Mark Sims wrote: > It would be pretty easy to teach Lady Heather how to do it. Heather > already supports several different audible clock. One issue would be > constructing the message from several snippets. Currently Heather plays > sound files asynchronously and if you start one file before the last one > has completed they get mixed together. Another issue to work out is the > length of the combined message so that you know when to trigger playback. > I would do it like WWV. Have the time pulse generated artificially and its audio synchronized, and have the voice mixed over the top. So long as the voice message completes before the time mark, everything is fine. That would allow the simple time pulse to be synchronous and the voice to be asynchronous. -- Brian Lloyd 706 Flightline Spring Branch, TX 78070 br...@lloyd.aero +1.210.802-8FLY (1.210.802-8359) ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Bombe clock
On 5/22/19 12:37, Jean-Louis Rault wrote: > What is the purpose of the full RGB lighting under the tubes ? > > Is it for any cosmo-quantic synchronization of the free electrons > spins used as time reference ? > > Or to justify the price ? No, it is because that comes on the $100 nixie tube clock board they are using to drive the displays. I have the same board with the same features on my nixie tube clocks. I like setting the LEDs for that cool purple glow that the old gas VR tubes exhibited. 0A2 anyone? > > Jean-Louis F6AGR -- Brian Lloyd 706 Flightline Spring Branch, TX 78070 +1.210.802.8359 ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Bombe clock
On 5/21/19 12:54, Mark Sims wrote: > Everbody needs one of these... > > https://www.ebay.co.uk/itm/The-Covert-Bombe-Clock-from-Bad-Dog-Designs-Codebreaking-in-Secret/123775434764 > > https://www.youtube.com/watch?v=O4ctUqgj7aY Definitely. Now, if only the dials rotated to indicate the time instead of nixie tubes, which didn't exist back then. Hmmm, a GPS receiver, an arduino, 6 stepper motors ... The craftsmanship is nice. The price, not so much. ;-) -- Brian Lloyd 706 Flightline Spring Branch, TX 78070 +1.210.802.8359 ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Li Ion Battery for HP 5065A
On 3/8/19 15:41, ew via time-nuts wrote: > A123 7Ah "brick" LiFePO4 who is the vendor?Bert Kehrren I sent this information several days ago. I guess my message never posted. Check with Bioenno Power: https://bioennopower.com This may be a drop-in replacement: https://bioennopower.com/collections/12v-series-lifepo4-batteries/products/12v-8ah-lfp-battery-abs-sealed-black-case -- Brian Lloyd 706 Flightline Spring Branch, TX 78070 +1.210.802.8359 ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Li Ion Battery for HP 5065A
On 3/7/19 15:36, ew via time-nuts wrote: > > Having recently acquired a HP 5065A with clock I decided to put a battery in > it. My choice is 5000 mA Lithium Ion. Having in the past very good experience > with a Florida vendor, was first choice. Sadly he is going out of business. > 90+% out there is junk, have 26650s with 1800 mA. Last week finally located a > reliable vendor, purchased seven 21700 Samsung B50s, reasonable price. 21700 > is a better fit in the 50 X 65 X175 mm battery frame. After extensive dialog > with vapah.inc and bench tests of all seven 4800 to 5200 mA, I am convinced > that I found in the US a very viable source. No commercial or any other > interest, now my only problem is how to get rid of the other junk. https://bioennopower.com/ I use their LiFePO4 batteries to build packs for lots of different kit. -- Brian Lloyd 706 Flightline Spring Branch, TX 78070 +1.210.802.8359 ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] simple phase finder
On Wed, Dec 5, 2018 at 8:52 AM jimlux wrote: > On 12/5/18 6:32 AM, Bob kb8tq wrote: > > Hi > > > >> On Dec 5, 2018, at 8:45 AM, jimlux wrote: > >> > >> On 12/5/18 5:39 AM, Poul-Henning Kamp wrote: > >>> > >>> In message <4a8ff8d6-70b2-782e-cb79-21c7e9a49...@earthlink.net>, > jimlux writes: > >>>> If I were decoding WWVB to start, I'd break my samples up into 0.1 > >>>> second or 0.5 second chunks and process them to see what the carrier > >>>> phase is. > >>> With stable signals like this, it is a bad idea to chop them up, > >>> in particular if your ADC runs from a good stable frequency. > >> > >> True enough - this was just to get started. > >> > >>> Instead continuously average the square of the signal into a 1 > >>> second long circular buffer. > >>> Then multiply/sum that buffer with a 120kHz sine and cosine to find > >>> the phase angle. > >> > >> yes.. assuming your ADC is running off a sufficiently stable source. I > was thinking about a very low cost implementation where the ADC is running > off a not very wonderful microcontroller clock. > Are you aware that the KiwiSDR receivers are locked to GPS and time-stamp their samples? Some people are playing with TDoA location of HF emitters using multiple KiwiSDRs out there. > > > A stable clock probably is a pretty good bet on a “Time Nut” grade > design. Indeed one objective might be to ultimately > > read out the phase directly WRT that reference . Some sort of PPS tick > likely would get into all this as well. > Yeah, do more research into the KiwiSDR. > > > > > > I was thinking more about "can you receive it with a SDR implementation > for <$50 and minimal heating of the soldering iron" without worrying too > much about measuring small phase shifts. > > Once you've got to that - then you've got a basis for further improvements. > > I'll try the RTL-SDR with a non-active antenna on Friday and see what I > can see here in Southern California. I know my old style "atomic" clock > does see the signal sometimes, so I can grab some sample when the clock > says it's live. > > > If anyone has a suggestion for an off the shelf active antenna that's > orderable and receivable by Friday, I'd love to hear it. There's 3 or 4 > of them I've seen (Clifford labs, DX Engineering has one, I'm sure MFJ > has one) > I have the PixelSat loop (now sold by DX Engineering) and it works great at 60kHz. I hear WWVB 7x24 in San Antonio. MFJ has a cheaper version that I've heard works OK. I have my loop driving my KiwiSDR. I haven't made it public (yet). I hear WWVB with it just peachy all the time. > Why available by Friday? I'm going to be really busy starting next week > for a month commissioning a satellite launching next week, so this > weekend is my last opportunity to fool with actual technology. > DX Engineering or MFJ. You might find that HRO has one or the other in stock. Don't they have a store in Las Vegas, not too far from you? UPS ground should get to you in a day. -- Brian Lloyd 706 Flightline Spring Branch, TX 78070 br...@lloyd.aero +1.210.802-8FLY (1.210.802-8359) ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] OCXO info
On Fri, Nov 2, 2018 at 11:40 PM, DM wrote: > Brian, > The support board part number indicates that it was used in a model HP > 5328A or B counter. I find that some versions of that model used a > 05328-60027 board. Maybe you misread the part number? > No, the number etched into the board is 05328-20027. It is very clear. On the other side of the board is an ink stamp which reads 05328-60038. Is it possible that the stamped number is the assembly number while the etched number is for the board itself? Anyway, There are a number of complete manuals for the 5328A & B counters > on the web, available for free download. Here are a few links: > http://bama.edebris.com/manuals/ > http://www.ebaman.com/index.php/remository/ELECTRONICS/Test-Equipment/ > http://www.ko4bb.com/manuals/ > http://www.keysight.com/main/facet.jspx?t=79910.g.3=US=eng=g=0 > > A check into the Federal Supply System indicates that that model > oscillator was an alternate for the venerable 10544 and 10811 oscillators, > so pinouts should be the same as those models. > Thank you. > Cheers, > Dave M > > > > > > - Original Message - > > From: "Brian Lloyd" > To: "Discussion of precise time and frequency measurement" < > time-nuts@lists.febo.com> > Sent: Friday, November 2, 2018 7:29:53 PM > Subject: [time-nuts] OCXO info > > I have an OCXO I pulled from a dead HP counter. The oscillator itself is a > Piezo Systems 2810007-1 and it is plugged into, what appears to be, a > buffer board, HP part number D23703F 05328-20027. > > Three questions: > > 1. Does anyone have the pinout for the oscillator? > > 2. Does anyone have the pinout for the buffer board? > > 3. Does anyone have a 15-pin card-edge connector for the buffer board? > > My plan is to turn it into a GPSDO. > > -- > > > > Brian Lloyd > 706 Flightline > Spring Branch, TX 78070 > br...@lloyd.aero > +1.210.802-8FLY (1.210.802-8359) > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to http://lists.febo.com/mailman/ > listinfo/time-nuts_lists.febo.com > and follow the instructions there. > > _______ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to http://lists.febo.com/mailman/ > listinfo/time-nuts_lists.febo.com > and follow the instructions there. > -- Brian Lloyd 706 Flightline Spring Branch, TX 78070 br...@lloyd.aero +1.210.802-8FLY (1.210.802-8359) ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
[time-nuts] OCXO info
I have an OCXO I pulled from a dead HP counter. The oscillator itself is a Piezo Systems 2810007-1 and it is plugged into, what appears to be, a buffer board, HP part number D23703F 05328-20027. Three questions: 1. Does anyone have the pinout for the oscillator? 2. Does anyone have the pinout for the buffer board? 3. Does anyone have a 15-pin card-edge connector for the buffer board? My plan is to turn it into a GPSDO. -- Brian Lloyd 706 Flightline Spring Branch, TX 78070 br...@lloyd.aero +1.210.802-8FLY (1.210.802-8359) ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Lots of Off Topic discussion
On Sat, Sep 1, 2018 at 9:13 AM, David G. McGaw wrote: > I consider saving WWV/WWVH/WWVB to be ON topic. They may not be as > precise as some on this list like to achieve, but they are publicly > available methods of time dissemination. I am very concerned that factions > of NIST consider that this should no longer be part of their mission. > I think it is still on-topic for the following reasons: 1. In many parts of the world, WWV is still a convenient time reference. You can get human-accurate time with nothing more than a $20 shortwave receiver. No, it is not time-nuts accurate but it will do for most things that people do, including celestial navigation and knowing when to come to dinner. 2. It is a stable RF source for people monitoring changes in the the ionosphere. Whatever else it is, we KNOW they are emitting ON 2.5, 5, 10, 15, 20, and 25 MHz. I also consider the discussion of GPS jamming to be relevant because, for people who DO want/need time-nuts accuracy, GPS is far and away the most convenient reference. Knowing how it might fail is useful. YMMV. -- Brian Lloyd 706 Flightline Spring Branch, TX 78070 br...@lloyd.aero +1.210.802-8FLY (1.210.802-8359) ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] WWV and legal issues
On Thu, Aug 30, 2018 at 9:42 AM, Scott McGrath wrote: > Um no > > Will the internet continue to route packets without precision timing yes > it will, Yes the lambdas will stay lit on fiber but the ATM transport that > runs on the lambdas will fail (note DSL is simply an ATM VC over copper). > and other timing dependent services will fail > You may find less ATM on the fast links than you think. > > Will many services like authentication continue especially those based on > multimaster replication continue to function? > > No they will not, they are totally dependent on precision timing to > ensure proper replication sourcing. (Microsoft Active Directory) Precision timing better than NTP? Are you sure? I guess there are some using Microsoft stuff but the fabric of the Internet sure doesn't depend on it. > > Banking transactions in the same boat. > Same question. > > Unless you’ve actually run a large network you dont realize just how > dependent on precision timing the services running over the network have > become especially authentication And one reason for this is increased > security for the overall network. > Yeah, I have some experience with running a large net. I have a little experience with how the Internet runs. ;-) -- Brian Lloyd 706 Flightline Spring Branch, TX 78070 br...@lloyd.aero +1.210.802-8FLY (1.210.802-8359) ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Setting Time on WSPR Radio Transmitter
On Fri, Jun 22, 2018 at 1:27 PM, Hal Murray wrote: > > bro...@pacific.net said: > > I'm experimenting with a WSPR beacon transmitter and part of how it works > > depends on pushing the start button at exactly 2 seconds past the > minute. > > What do you mean by "exactly"? > I think WSPR has a +/-2s window for the start of a transmission. It really isn't all that "exact" and certainly nothing in the way of time-nuts definition of accuracy. The most popular WSPR implementation runs on a PC and uses a sound-card to generate the baseband signal and then uses an SSB transceiver to upconvert to the desired output frequency. Even worst-case the standard NTP implementation on Windows is more than sufficient for synchronization. -- Brian Lloyd 706 Flightline Spring Branch, TX 78070 br...@lloyd.aero +1.210.802-8FLY (1.210.802-8359) ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to https://lists.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
