Re: [time-nuts] Portable Time Standard
On 1/11/19 12:26 PM, Bob kb8tq wrote: Hi The most common approach to “monitor” a quartz movement is to listen to it at 32,768 KHz with a tuned microphone. If it is an analog movement, then one can detect the sound of the motor driving the mechanical side. Do you need a device with a visual readout or are you after something that gives you an electrical signal (like a PPS)? Is DIY ok in this application? If so, there are a lot of TCXO’s out there that will do at least as well as what you are looking for. A very different approach would be a GPS (or WWVB) module with a battery attached to it. I mis-spoke in my recent response.. 0.3 ppm is very challenging for a TCXO in a wide temp range, but I just realized you're 0-35C.. that's not that tough at all. If a watch is “ok”, there are WWVB and GPS watches that will do much better than 1 second accuracy for not very insane sort of prices. Bob ___ 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] Portable Time Standard
On 1/11/19 11:57 AM, Joe Hobart wrote: I need a relatively lightweight, self powered, portable clock accurate to 1 second per month. Temperatures may range from 10 to 35 C; altitude from 1000 to 7000 feet. Although expensive, some of the marine quartz chronometers appear to meet this requirement. ~0.3 PPM. Any particular display or power requirements? For instance, an inexpensive battery powered GPS would meet your requirement, but presumably isn't appropriate for some reason - ditto with any of the 60 kHz receiver based "Atomic clocks" 0.3 ppm is tighter than most inexpensive TCXOs. Does anyone have any experience with these devices? If so, has anyone tried to detect the probably weak magnetic field generated by the clock mechanism for time comparison purposes? Thanks, Joe, W7LUX --- This email has been checked for viruses by AVG. https://www.avg.com ___ 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] Expected behaviour from net4501, oncore and ntpns?
Hi all, I got my Soekris net4501 hooked up to an oncore module and antenna and ntpns has been talking nicely to the oncore. After a couple of hours it started to serve NTP to a client however the time shown for the net4501 on the NTP client is approx. 600s slow (see last line): $ ntpq -p remote refid st t when poll reach delay offset jitter == *reverb.baxterit 213.251.128.249 2 u 78 256 377 17.8590.575 2.196 +k8s-w01.tblflp. 152.2.133.53 2 u 12 256 377 17.9922.945 1.153 +ip225.ip-54-39- 213.251.128.249 2 u 260 256 377 18.229 -0.193 1.611 x192.168.1.44.GPS.1 u 18 256 3770.830 -619315 0.484 Also the time of day displayed in 'show oncore 0' is correct, but the year is wrong (I've obfuscated the position data in the output, but it's essentially correct): show oncore 0 serial port = /dev/cuau1 state = 12 visible/track/lock = 13/2/0 dop = 0.0 [m] 1999-05-28 22:02:02.16953 Leap second info: 2017-01-01 00:00:00 NONE 555299878 seconds (6427 days) from now lat = xxx (xx.x), lon = xxx (xx.xxx), ht (xx.xx) http://maps.google.com/maps?ll=xx.xxx,xx.xxx=0.03,0.08=k rcv_status = 0x8 = AcqSat/PosHold utc_offset = 18 site_survey = 2 (~3073 sec left) Sat Dopler Elev Azi Health Mode SigStr IODE Status Offset 8 3828 12 180 00 841 0a2 0.134221487 23969 62 279 00 3 0 020 0.385877161 26 -2039 55 52 00 3 0 020 0.436211366 27 3287 32 157 00 846 0a2 0.452988591 Output from 'show source' and 'show oncore 0 version' is: show source Source oncore_0: votes 3.00 flags los 0/15 update 1 SELECTED limit 1.28e-01 No leapsecond at end of today stratum 0 refid [GPS] delay 0.0 dispersion 0.00512 last_ts 927928914.00102last_delta 0.00103 show oncore 0 version @@Cj COPYRIGHT 1991-1997 MOTOROLA INC. SFTW P/N # 98-P36848P SOFTWARE VER # 3 SOFTWARE REV # 1 SOFTWARE DATE May 28 1999 MODEL #R5122U1154 HWDR P/N # 5 SERIAL # R0ANKH MANUFACTUR DATE 0M19 I see that the site_survey is still happening - will things correct themselves if I leave it long enough? Toby ___ 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] Division and resolution
Hi, Can we consider that the phase data record obtained from a Divided Frequency source is equivalent to reducing resolution from the phase data record obtained from the undivided source ? In such case the “effect of data resolution” discussion from following paper: http://www.leapsecond.com/pages/adev-avg/ would apply. Thx, Gilles. ___ 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] Portable Time Standard
You might try a telephone pickup coil to detect the magnetic "ticks" from a quartz clock. They even come with a plug and a suction cup! On Fri, Jan 11, 2019 at 3:34 PM Tim Shoppa wrote: > > I am not an expert in every quartz clock mechanism BUT a 1-10mH nonshielded > inductor makes an excellent pickup for the "ticks" from any quartz clock or > watch that I've ever met. > > > -- --Jim Harman ___ 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] Portable Time Standard
Many of the 70's/80's Japanese marine quartz chronometers had a test button that gave you an audible beep every second. I am not an expert in every quartz clock mechanism BUT a 1-10mH nonshielded inductor makes an excellent pickup for the "ticks" from any quartz clock or watch that I've ever met. Tim N3QE On Fri, Jan 11, 2019 at 3:04 PM Joe Hobart wrote: > I need a relatively lightweight, self powered, portable clock accurate to 1 > second per month. Temperatures may range from 10 to 35 C; altitude from > 1000 to > 7000 feet. Although expensive, some of the marine quartz chronometers > appear to > meet this requirement. ~0.3 PPM. > > Does anyone have any experience with these devices? > > If so, has anyone tried to detect the probably weak magnetic field > generated by > the clock mechanism for time comparison purposes? > > Thanks, > Joe, W7LUX > > --- > This email has been checked for viruses by AVG. > https://www.avg.com > > > ___ > 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.
Re: [time-nuts] Portable Time Standard
Hi The most common approach to “monitor” a quartz movement is to listen to it at 32,768 KHz with a tuned microphone. If it is an analog movement, then one can detect the sound of the motor driving the mechanical side. Do you need a device with a visual readout or are you after something that gives you an electrical signal (like a PPS)? Is DIY ok in this application? If so, there are a lot of TCXO’s out there that will do at least as well as what you are looking for. A very different approach would be a GPS (or WWVB) module with a battery attached to it. If a watch is “ok”, there are WWVB and GPS watches that will do much better than 1 second accuracy for not very insane sort of prices. Bob > On Jan 11, 2019, at 2:57 PM, Joe Hobart wrote: > > I need a relatively lightweight, self powered, portable clock accurate to 1 > second per month. Temperatures may range from 10 to 35 C; altitude from 1000 > to > 7000 feet. Although expensive, some of the marine quartz chronometers appear > to > meet this requirement. ~0.3 PPM. > > Does anyone have any experience with these devices? > > If so, has anyone tried to detect the probably weak magnetic field generated > by > the clock mechanism for time comparison purposes? > > Thanks, > Joe, W7LUX > > --- > This email has been checked for viruses by AVG. > https://www.avg.com > > > ___ > 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] Thunderbolt+PRS10+TAPR/TICC
I am wanting some general advice on the following: I currently have among my timing-related devices a couple of Trimble Thunderbolts (a silver one w/ the inbuilt power supply and a gold flat one), a PRS10, and a TAPR/TICC. My current end goal is to use these to get an idea of the quality of the 1PPS output from various consumer (not timing) GPS receivers. My thought is to clock the TAPR/TICC from the PRS10, and then just capture the relative timestamp of each 1PPS from the GPS receiver. Using this, I think I should be able to at least get a relatively good histogram of the 1PPS nanosecond phase error, and analyze the number of outliers/missing pulses. Possibly do some other analysis, but that would be a bonus. Feel free to correct my terminology if I've mangled it horribly. My current plan is to mount one of the thunderbolts (probably the silver one for electrical and mechanical reasons) and the PRS10 in a good quality heatsink benchtop instrument case, and power it from a 24V charger+battery array and leave it on permanently. When not in use for the measurement above, I'd just leave the 1PPS from the thunderbolt connected to the PRS10 and use that to discipline the PRS10 and use the outputs from the PRS10 for day-to-day use. However, when I'm doing the 1PPS measurement described above, it seems to me that it is probably best for the PRS10 to be freerunning, to avoid any contamination of the measurement by the PRS10 being disciplined. (Feel free to correct me if I'm wrong) So my question is if the above seems like a reasonable course of action? I also am curious about the best way to switch the PRS10 from disciplined to freerunning/holdover to avoid any contamination from the disconnection of the Thunderbolt. Any other suggestions/hints for doing this type of measurement would be helpful. Assume I know just enough to be dangerous. Thanks, -forrest ___ 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] Portable Time Standard
I need a relatively lightweight, self powered, portable clock accurate to 1 second per month. Temperatures may range from 10 to 35 C; altitude from 1000 to 7000 feet. Although expensive, some of the marine quartz chronometers appear to meet this requirement. ~0.3 PPM. Does anyone have any experience with these devices? If so, has anyone tried to detect the probably weak magnetic field generated by the clock mechanism for time comparison purposes? Thanks, Joe, W7LUX --- This email has been checked for viruses by AVG. https://www.avg.com ___ 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] Short term 10MHz source (and unrelated comment)
Magnus, I am very sorry for speaking out of turn. Few messages earlier you have referred to the raw PPS and I thought I might offer an insight to what is happening inside Ublox chipset hardware that is otherwise not know to vast majority of its users, including most members here. I only speak up when I think I can offer something others cannot. Perhaps, I should have quoted your other message. Perhaps, I should have just continued reading instead. > From: Magnus Danielson > For some GPSDOs you get a PPS and is "raw" from GPS module and not > resynthesized from the steered 10 MHz. > Now, if one uses this PPS it would get quite a bit of noise, but if one was > to measure that noise against the smoothed 10 MHz with a separate TIC/TICC > one should be able to use the PPS as a transfer oscillator with > the right rate but get close to the smoothed 10 MHz as stability. > From: Magnus Danielson > Recall that the quantization is really a form of time-stamp value for > the channel in it's relation to the time-base. It's a systematic pattern > in the time-base clock and it is phase-locked to the time-base phase. > ... > So, to conclude, the quantization noise that we have is very systematic > in its nature, > On 1/9/19 10:10 AM, Leo Bodnar wrote: >> Depends what you call "systematic"... > > From: Magnus Danielson > Leo, > Now, what I was talking about was frequency/time-interval counters in > this case, not GPS-chips or GPSDOs. So, your comment seems out of > context in that regard. I feel increasingly uncomfortable posting here as one gets subtly condescending remarks from celebrated members of what comes across as an elite club of few dozen intellectuals discussing same few topics in rounds. I am only mentioning this in light of TVB's unexpected post on EEVBlog (which is at the other extreme of creative engineering community) that seemingly invites new members to join the list. These two establishments can't be further apart in their culture and average knowledge level and I am fascinated to see what might happen as a result. Thanks Leo ___ 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] Misuse of word "decimate" (was Re: Short term 10MHz source)
In message <293ce126-e9ef-40a2-e742-966d638cf...@rubidium.se>, Magnus Danielson writes: I can add that as of this morning, "decimate" is also used for the act of reading only every Nth email in a long thread :-) -- 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@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
