[time-nuts] Re: PCTEL Timing Antenna with integrated GPS Receiver?
Hi One would guess that the GPS module in the device is something fairly normal. Motorola modules showed up in the early versions of this gizmo. Bob > On May 9, 2021, at 9:00 PM, John Miller via time-nuts > wrote: > > Tom, > Thanks for sharing - this looks very interesting. I don’t think it’s quite > identical, though. The unit I got was available in 232 and 422 (the one > coming to me is 232), and the data sheet for the PCTEL lists it as a 12 > channel receiver, whereas the 58534A is an 8 channel. > > Once it’s in my hands and I crack it open I’ll post pictures and we can > figure out for sure! > > John > >> On May 9, 2021, at 4:28 PM, Tom Van Baak wrote: >> >> The equivalent hp integrated timing antenna was the 58534a. You may find its >> documentation helpful: >> >> http://leapsecond.com/museum/hp58534a/ >> >> /tvb >> >> >> On 5/8/2021 6:36 PM, John Miller via time-nuts wrote: >>> I did mean this unit in particular, specifically I’m really interesting in >>> turning up the pinout for that connector. I have at least been able to find >>> a mating end for it. My past hour of furious googling has turned up >>> surprisingly little about this model. I am very interested in how it >>> performs. >>> >>> John >>> >> ___ >> time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an >> email to time-nuts-le...@lists.febo.com >> To unsubscribe, go to and follow the instructions there. > ___ > time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an > email to time-nuts-le...@lists.febo.com > To unsubscribe, go to and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.
[time-nuts] Re: PCTEL Timing Antenna with integrated GPS Receiver?
Tom, Thanks for sharing - this looks very interesting. I don’t think it’s quite identical, though. The unit I got was available in 232 and 422 (the one coming to me is 232), and the data sheet for the PCTEL lists it as a 12 channel receiver, whereas the 58534A is an 8 channel. Once it’s in my hands and I crack it open I’ll post pictures and we can figure out for sure! John > On May 9, 2021, at 4:28 PM, Tom Van Baak wrote: > > The equivalent hp integrated timing antenna was the 58534a. You may find its > documentation helpful: > > http://leapsecond.com/museum/hp58534a/ > > /tvb > > > On 5/8/2021 6:36 PM, John Miller via time-nuts wrote: >> I did mean this unit in particular, specifically I’m really interesting in >> turning up the pinout for that connector. I have at least been able to find >> a mating end for it. My past hour of furious googling has turned up >> surprisingly little about this model. I am very interested in how it >> performs. >> >> John >> > ___ > time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an > email to time-nuts-le...@lists.febo.com > To unsubscribe, go to and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.
[time-nuts] Re: The amazing $5 timestamper, part 2: discovering a bug in my signal generator
Hi Tobias, In the latest round of experiments in which the clock resolution was 6ns, I could not detect any instability; the timestamps of the 1pps signal being fed into my timestamper had identical low order bits for 250,000 seconds (until I stopped the experiment). In this case the 10mhz reference was PLLed up using the STM32's internal PLL, x17, to 170 mhz. The next step is to use the "HRTIM" peripheral which has a second PLL, x32, that will yield 184ps resolution. The system clock will not go above 170mhz; 5.4ghz is only the internal clock of the HRTIM peripheral. Once I am able to do that experiment, I might see instability, in which case my backup plan is to use an external PLL chip to feed a more stable 170mhz signal directly to the STM32's timer peripheral. On Wed, May 5, 2021 at 5:43 AM Pluess, Tobias wrote: > Hi Jeremy > > I assume you use the inertnal PLL of the STM32 to get this amazing 184ps > resolution. > Can you say something about the frequency stability of that PLL? > In my very first GPSDO I built, I used a STM32F303. This one had a quite > bad PLL stability, the frequency was varying over time in a sawtooth like > manner for some reason. My GPSDO was only stable when I disabled the PLL > and let the entire MCU run from the 10 MHz OCXO. > > In my current GPSDO, I use the STM32F407. I have not tested the PLL yet, so > currently everything also runs from the 10 MHz clock. I am still testing my > design since almost a year, and it works quite stable and reliable, but if > I could use the PLL, that would allow me to improve my algorithms and stuff > and would let me even connect a small LCD panel to the MCU for status > display. Currently, with only 10 MHz clock, the CPU is a bit too slow ;-) > > So it would be interesting to see what the stability of that PLL is. While > I do not use the same MCU as you do, it could still be interesting for > comparison. > > Best > Tobias > HB9FSX > > > On Sat, Apr 24, 2021 at 9:38 PM Jeremy Elson wrote: > > > A few months ago, posted to the list about a new device I'm designing > based > > on the latest-generation STM32 CPUs. I'm back to post about some > > improvements to it -- and, it's now good enough that it found a frequency > > error of 1 part in 1e11 in my Rigol DS1022Z signal generator! Read on for > > the story. > > > > To recap, the relatively new STM32G4 series of ARM Cortex > microcontrollers > > have high resolution timers capable of 184 picosecond resolution, and I > am > > using it to build a device that can timestamp an arbitrarily long > sequence > > of events, on 4 channels, with 184ps resolution and under 1 microsecond > of > > dead time between events. The first time I posted, it was after a > feverish > > 3-day hackathon getting an early prototype built on a breadboard. I > posted > > some (very) preliminary results using a Rubidium frequency reference to > > timestamp the PPS signal coming from my GPS. There were odd jumps in the > > timestamps. At the time, I attributed that (incorrectly, it turns out) to > > the GPS losing and regaining lock. > > > > After a lot of careful analysis, and some helpful feedback from other > > time-nuts, I decided it was better to do some better-controlled > experiments > > to pin down where the errors were coming from. I found and fixed a number > > of sources of error: > > > > (1) I realized the gaps were all 100ns of the timestamper falling behind, > > which is exactly one tick of the 10mhz reference clock. It turned out my > > analog circuit for conditioning the 10mhz, 1.8vpp, 0-centered sine wave > > generated by the reference clock into something that could be used as an > > STM32 clock input was not boosting the voltage quite high enough; the > STM32 > > was sometimes missing pulses. I redesigned it to prevent this. > > > > (2) I then found another class of error: the clock going too *fast,* > again > > with 100ns gaps. This turned out to be noise on the clock line causing > > spurious pulses, which was because it's hard to keep noise out of a > > breadboarded circuit full of long wires and clips. I designed and > > fabricated a proper printed circuit board for testing. > > > > To differentiate errors introduced by my timestamper from errors in the > > devices I was using to test it, I set up an experiment that drove the > > timetsamper and the test signal from the same clock source. My first > setup > > was to use a Rubidium oscillator (lpro 101) as the master clock for both > > the timestamper and a test pulse. I fed the RbXO's reference clock into > > both my signal generator (a Rigol DG1022Z) and my timestamper, and I > > configured the DG1022Z to generate a 1us-wide pulse every second. This > came > > close to working, but as you can see in this graph of residual errors ( > > > > > https://www.circlemud.org/jelson/2020-04-01_proper_connectors_1pps_rubidium.time.plot.png > > ), > > there was a small frequency error of about 1 part in 1e11. The resolution > > of the timestamps was
[time-nuts] Re: PCTEL Timing Antenna with integrated GPS Receiver?
The equivalent hp integrated timing antenna was the 58534a. You may find its documentation helpful: http://leapsecond.com/museum/hp58534a/ /tvb On 5/8/2021 6:36 PM, John Miller via time-nuts wrote: I did mean this unit in particular, specifically I’m really interesting in turning up the pinout for that connector. I have at least been able to find a mating end for it. My past hour of furious googling has turned up surprisingly little about this model. I am very interested in how it performs. John ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.
[time-nuts] Re: PCTEL Timing Antenna with integrated GPS Receiver?
> Generally speaking once power and ground are found everything else more or > less falls in place. Can you figure out power/ground with an ohmmeter? Or perhaps a battery, resistor, and voltmeter? Is the shell of the connector directly connected to one of the pins? -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.
[time-nuts] Re: PCTEL Timing Antenna with integrated GPS Receiver?
paul swed writes: > I have used some pctel antennas and they have been very good over the > years. (Very good = works). The model number at least gives you a hint if > RS 422 or 232. But if you can't find any further detail you are stuck with > one option. If you can figure out how to power it, it is pretty trivial to see if the data stream is single-ended (RS232) or differential (RS422) -- 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 send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.
[time-nuts] Re: PCTEL Timing Antenna with integrated GPS Receiver?
John Totally agree on the power and ground. Good to know you like to take them apart if required. On Sun, May 9, 2021 at 2:09 PM John Miller via time-nuts < time-nuts@lists.febo.com> wrote: > I take everything apart, so that much is a given - I just also like to > have as much original documentation as I can, especially if there are any > special initialization or configuration commands. Whatever I find I will > document for anyone else who gets one of these in the future. Generally > speaking once power and ground are found everything else more or less falls > in place. > > John > > > On May 9, 2021, at 10:48 AM, paul swed wrote: > > > > Back to the problem for a minute. > > I have used some pctel antennas and they have been very good over the > > years. (Very good = works). The model number at least gives you a hint if > > RS 422 or 232. But if you can't find any further detail you are stuck > with > > one option. > > Open it up and look. Most of these antennas can be opened and then > > re-assembled. The hardest part is ensuring a good seal. > > With respect to what's inside it should be reasonably apparent. Ground, > > Power to some linear regulator, maybe a RS422 chip or 232 driver. > Expected > > leads for 422 nema and 1 pps so that would be 4 pins right there. > > So you would be able to get the unit going if your willing to dig in. Pun > > intended. > > Good luck and let us know what you find. > > Regards > > Paul > > WB8TSL > > > > On Sun, May 9, 2021 at 8:11 AM Poul-Henning Kamp > wrote: > > > >> > >> Mike Ingle writes: > >> > >>> Hi, in reading between the lines, are you saying that in practice, the > >>> tempco of twisted pair is worse than the tempco of coax? > >> > >> I seriously doubt it. The change in coppers conductivity will not make > >> that kind of difference in propagation time until the cables are > measured > >> in kilometers. > >> > >> I suspect the tempco comes from the RS-422 linedriver chip in the > antenna > >> or possibly from ceramic capacitors used to control its slew-rate. > >> > >> -- > >> 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 > send > >> an email to time-nuts-le...@lists.febo.com > >> To unsubscribe, go to and follow the instructions there. > >> > > ___ > > time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe > send an email to time-nuts-le...@lists.febo.com > > To unsubscribe, go to and follow the instructions there. > ___ > time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send > an email to time-nuts-le...@lists.febo.com > To unsubscribe, go to and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.
[time-nuts] Re: PCTEL Timing Antenna with integrated GPS Receiver?
I take everything apart, so that much is a given - I just also like to have as much original documentation as I can, especially if there are any special initialization or configuration commands. Whatever I find I will document for anyone else who gets one of these in the future. Generally speaking once power and ground are found everything else more or less falls in place. John > On May 9, 2021, at 10:48 AM, paul swed wrote: > > Back to the problem for a minute. > I have used some pctel antennas and they have been very good over the > years. (Very good = works). The model number at least gives you a hint if > RS 422 or 232. But if you can't find any further detail you are stuck with > one option. > Open it up and look. Most of these antennas can be opened and then > re-assembled. The hardest part is ensuring a good seal. > With respect to what's inside it should be reasonably apparent. Ground, > Power to some linear regulator, maybe a RS422 chip or 232 driver. Expected > leads for 422 nema and 1 pps so that would be 4 pins right there. > So you would be able to get the unit going if your willing to dig in. Pun > intended. > Good luck and let us know what you find. > Regards > Paul > WB8TSL > > On Sun, May 9, 2021 at 8:11 AM Poul-Henning Kamp wrote: > >> >> Mike Ingle writes: >> >>> Hi, in reading between the lines, are you saying that in practice, the >>> tempco of twisted pair is worse than the tempco of coax? >> >> I seriously doubt it. The change in coppers conductivity will not make >> that kind of difference in propagation time until the cables are measured >> in kilometers. >> >> I suspect the tempco comes from the RS-422 linedriver chip in the antenna >> or possibly from ceramic capacitors used to control its slew-rate. >> >> -- >> 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 send >> an email to time-nuts-le...@lists.febo.com >> To unsubscribe, go to and follow the instructions there. >> > ___ > time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an > email to time-nuts-le...@lists.febo.com > To unsubscribe, go to and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.
[time-nuts] Re: PCTEL Timing Antenna with integrated GPS Receiver?
Back to the problem for a minute. I have used some pctel antennas and they have been very good over the years. (Very good = works). The model number at least gives you a hint if RS 422 or 232. But if you can't find any further detail you are stuck with one option. Open it up and look. Most of these antennas can be opened and then re-assembled. The hardest part is ensuring a good seal. With respect to what's inside it should be reasonably apparent. Ground, Power to some linear regulator, maybe a RS422 chip or 232 driver. Expected leads for 422 nema and 1 pps so that would be 4 pins right there. So you would be able to get the unit going if your willing to dig in. Pun intended. Good luck and let us know what you find. Regards Paul WB8TSL On Sun, May 9, 2021 at 8:11 AM Poul-Henning Kamp wrote: > > Mike Ingle writes: > > > Hi, in reading between the lines, are you saying that in practice, the > > tempco of twisted pair is worse than the tempco of coax? > > I seriously doubt it. The change in coppers conductivity will not make > that kind of difference in propagation time until the cables are measured > in kilometers. > > I suspect the tempco comes from the RS-422 linedriver chip in the antenna > or possibly from ceramic capacitors used to control its slew-rate. > > -- > 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 send > an email to time-nuts-le...@lists.febo.com > To unsubscribe, go to and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.
[time-nuts] Re: PCTEL Timing Antenna with integrated GPS Receiver?
Mike Ingle writes: > Hi, in reading between the lines, are you saying that in practice, the > tempco of twisted pair is worse than the tempco of coax? I seriously doubt it. The change in coppers conductivity will not make that kind of difference in propagation time until the cables are measured in kilometers. I suspect the tempco comes from the RS-422 linedriver chip in the antenna or possibly from ceramic capacitors used to control its slew-rate. -- 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 send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.
[time-nuts] Re: PCTEL Timing Antenna with integrated GPS Receiver?
Hi, in reading between the lines, are you saying that in practice, the tempco of twisted pair is worse than the tempco of coax? Wouldn't any install where that was critical include a loopback to calibrate out cable delay? On Sun, May 9, 2021 at 8:27 AM Poul-Henning Kamp wrote: > > Douglas Baker writes: > > > I am trying to figure what the advantage is for an antenna with the > > built-in GPS receiver is. > > On reason is that the running the twisted pairs through standard > preinstalled lightning protection barriers is trivial, whereas > certifying and finding space for a suitable lightning barrier > for coax is a lot of work. > > Another advantage is that you can reuse existing cabling in rented > buildings, instead of paying sometimes unbeliveable amounts to run > your coax to the roof. > > (One of the main reasons Telecome Cesiums are still a thing, is that > they often are much cheaper than renting space for a GPS antenna > on the roof and cabled down to your kit in the basement.) > > However, one downside is that the PPS signals may suffer from tempco > on the order of 1 µs/K. > > -- > 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 send > an email to time-nuts-le...@lists.febo.com > To unsubscribe, go to and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.
[time-nuts] Re: PCTEL Timing Antenna with integrated GPS Receiver?
Douglas Baker writes: > I am trying to figure what the advantage is for an antenna with the > built-in GPS receiver is. On reason is that the running the twisted pairs through standard preinstalled lightning protection barriers is trivial, whereas certifying and finding space for a suitable lightning barrier for coax is a lot of work. Another advantage is that you can reuse existing cabling in rented buildings, instead of paying sometimes unbeliveable amounts to run your coax to the roof. (One of the main reasons Telecome Cesiums are still a thing, is that they often are much cheaper than renting space for a GPS antenna on the roof and cabled down to your kit in the basement.) However, one downside is that the PPS signals may suffer from tempco on the order of 1 µs/K. -- 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 send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.
[time-nuts] Re: PCTEL Timing Antenna with integrated GPS Receiver?
Hi John, I am trying to figure what the advantage is for an antenna with the built-in GPS receiver is. This was the approach many years ago when low noise/high gain pre-amps were not available. Today, the good LNA's are cheap and work great. Plus this limits the use to just one user end application. With the standard GPS antenna & LNA you can use a 4-port (or more) splitter and distribute the signal to several receivers. And the cost of 8-conductor cable is probably more expensive than good LMR coax for the same length of run. And if you have a long run you would have to use RS422 instead of RS232 for a reliable setup. Pctel is a good company and they have done well with the timing antenna design that they took over from Micro Pulse. But I just don't think this will be a big seller for them. The only possible reason I can come up with to go this route would be that you have a lot of RFI in the lab or wherever and need to remote the receiver away from the RFI source. And even then that's not a guarantee! 73's Doug Baker On Sat, May 8, 2021 at 7:35 PM John Miller via time-nuts < time-nuts@lists.febo.com> wrote: > Hello All, > I was browsing around looking at surplussed reference antennas, like you > do, and I stumbled across something really interesting and impulse bought > it because it was cheap enough. It’s a PCTEL GPS-TMG-RCVR232-NLM - the 232 > in the model name may catch your eye. Before reading the model number, what > got me was the connector on the bottom - not N or TNC like you may expect, > but a large aviation-style 8 pin DIN connector. > > I found a spec sheet here: > https://www.winncom.com/pdf/PCTel_GPS_TMG_RCVR/PCTel_GPS-TMG-RCVR_Series.pdf > < > https://www.winncom.com/pdf/PCTel_GPS_TMG_RCVR/PCTel_GPS-TMG-RCVR_Series.pdf > > > > Nothing too impressive, but it looks neat to me. As long as it doesn’t > have leap second issues, I’m going to incorporate it into the rest of my > stack. > > Has anyone ever used one of these before? Any familiarity? > > Regards, > John > ___ > time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send > an email to time-nuts-le...@lists.febo.com > To unsubscribe, go to and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.
