Re: [time-nuts] Trimble Thunderbolt 1pps
On 2014-01-27 23:32, Don Latham wrote: Mike S On 1/27/2014 1:33 PM, Robert Atkinson wrote: I looked at this a while ago. The spec only defines transmission levels, it does NOT specify receive thresholds. It certainly does... 2.1.3 For data interchange circuits, the signal shall be considered in the marking condition when the voltage on the interchange circuit, measured at the interface point, is more negative than -3 volts with respect to Circuit AB (Signal Common). The signal shall be considered in the spacing condition when the voltage is more positive than +3 volts with respect to Circuit AB (see 6.2). The region between +- 3 volts is defined as the transition region. The signal state is undefined when the voltage is in this transition region. - ANSI TIA/EIA-232-F (1997) we, maybe needed if you're running an ASR-33 teletype. . . Except ASR-33s came with a 20ma current loop interface. Later models added RS232 after it became popular. ISTR TWX terminals required one and Telex terminals the other. -- Take care. Thanks, Brian Inglis ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Trimble Thunderbolt 1pps
On Sun, 05 Jan 2014 13:35:43 -0800 Hal Murray hmur...@megapathdsl.net wrote: att...@kinali.ch said: Also keep in mind that RS-232 relies on the voltage going negative to encode a 1. I.e. getting 0V is not enough and might only work by chance with some RS-232 receivers. I think there are 2 parts to this discussion. What do the specs say, and what actually happens in the real world? I think the specs say that -3 to +3 is no mans land. A valid signal must be over +3 or under -3. IIRC that's right. But i haven't had a look at the standard for a very long time. In practice, the receiver chip only has one power supply. It would take extra work to make the switching threshold below ground. That's not correct. Standard transceiver chips (like the MAX232 family) have an integrated charge pump to get a negative power supply. I have never done exact measurements, but my experience is that going a bit (0.5V?) below GND and slightly more above GND is enough to get a proper 1/0 detection. Of course, if you rely on that you get a very poor noise performance. Attila Kinali -- The trouble with you, Shev, is you don't say anything until you've saved up a whole truckload of damned heavy brick arguments and then you dump them all out and never look at the bleeding body mangled beneath the heap -- Tirin, The Dispossessed, U. Le Guin ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Trimble Thunderbolt 1pps
On 27.01.2014 15:08, Attila Kinali wrote: In practice, the receiver chip only has one power supply. It would take extra work to make the switching threshold below ground. That's not correct. Standard transceiver chips (like the MAX232 family) have an integrated charge pump to get a negative power supply. Hello, The venerable MC1489 does not need a negative supply, and can have a threshold below ground, without too much complication. http://www.onsemi.com/pub_link/Collateral/MC1489-D.PDF (the receiver circuit diagram is shown) On the other side, the MAX232 has positive thresholds in the receiver side http://datasheets.maximintegrated.com/en/ds/MAX220-MAX249.pdf pag. 6 Regards, Javier ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Trimble Thunderbolt 1pps
OK I can add something here. Yes the spec is correct. But modern receiver chips actually can work with single side signals. You have to look at the specs of the chip to see what they will do. Granted noise immunity is much lower but for most of us in the 10' run distance its good enough. I operate this way on lots of things. Seriously sleazy way to get +/- swings as long as the data flows somewhat all of the time like GPS. Put the unipolar signal through a 1-10UF cap. Smaller is better to a point. Did I really suggest that. Will never admit it. Regards Paul. WB8TSL On Mon, Jan 27, 2014 at 9:08 AM, Attila Kinali att...@kinali.ch wrote: On Sun, 05 Jan 2014 13:35:43 -0800 Hal Murray hmur...@megapathdsl.net wrote: att...@kinali.ch said: Also keep in mind that RS-232 relies on the voltage going negative to encode a 1. I.e. getting 0V is not enough and might only work by chance with some RS-232 receivers. I think there are 2 parts to this discussion. What do the specs say, and what actually happens in the real world? I think the specs say that -3 to +3 is no mans land. A valid signal must be over +3 or under -3. IIRC that's right. But i haven't had a look at the standard for a very long time. In practice, the receiver chip only has one power supply. It would take extra work to make the switching threshold below ground. That's not correct. Standard transceiver chips (like the MAX232 family) have an integrated charge pump to get a negative power supply. I have never done exact measurements, but my experience is that going a bit (0.5V?) below GND and slightly more above GND is enough to get a proper 1/0 detection. Of course, if you rely on that you get a very poor noise performance. Attila Kinali -- The trouble with you, Shev, is you don't say anything until you've saved up a whole truckload of damned heavy brick arguments and then you dump them all out and never look at the bleeding body mangled beneath the heap -- Tirin, The Dispossessed, U. Le Guin ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Trimble Thunderbolt 1pps
Hi, I looked at this a while ago. The spec only defines transmission levels, it does NOT specify receive thresholds. All the receiver chips I've looked at, ancient and modern, have only positive thresholds. Most have single supplies and clamp the input at 1 diode drop negative WRT common after an input current limiting resistor, see the MC1489 datasheet. Even the MAX style devices with built-in charge pumps have a Input Logic-Low Voltage range of 0.8 to 1.3V Going negative does help with noise immunity. If you drive the TX to -9V then you need more than 9V of noise to loose the data. Robert G8RPI. From: paul swed paulsw...@gmail.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Monday, 27 January 2014, 14:44 Subject: Re: [time-nuts] Trimble Thunderbolt 1pps OK I can add something here. Yes the spec is correct. But modern receiver chips actually can work with single side signals. You have to look at the specs of the chip to see what they will do. Granted noise immunity is much lower but for most of us in the 10' run distance its good enough. I operate this way on lots of things. Seriously sleazy way to get +/- swings as long as the data flows somewhat all of the time like GPS. Put the unipolar signal through a 1-10UF cap. Smaller is better to a point. Did I really suggest that. Will never admit it. Regards Paul. WB8TSL On Mon, Jan 27, 2014 at 9:08 AM, Attila Kinali att...@kinali.ch wrote: On Sun, 05 Jan 2014 13:35:43 -0800 Hal Murray hmur...@megapathdsl.net wrote: att...@kinali.ch said: Also keep in mind that RS-232 relies on the voltage going negative to encode a 1. I.e. getting 0V is not enough and might only work by chance with some RS-232 receivers. I think there are 2 parts to this discussion. What do the specs say, and what actually happens in the real world? I think the specs say that -3 to +3 is no mans land. A valid signal must be over +3 or under -3. IIRC that's right. But i haven't had a look at the standard for a very long time. In practice, the receiver chip only has one power supply. It would take extra work to make the switching threshold below ground. That's not correct. Standard transceiver chips (like the MAX232 family) have an integrated charge pump to get a negative power supply. I have never done exact measurements, but my experience is that going a bit (0.5V?) below GND and slightly more above GND is enough to get a proper 1/0 detection. Of course, if you rely on that you get a very poor noise performance. Attila Kinali -- The trouble with you, Shev, is you don't say anything until you've saved up a whole truckload of damned heavy brick arguments and then you dump them all out and never look at the bleeding body mangled beneath the heap -- Tirin, The Dispossessed, U. Le Guin ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Trimble Thunderbolt 1pps
I pointed out a while ago that the modern chips like the MAX232 have a positive receiver threshold so TTL drive is fine for short runs. 73, David On 1/27/14 10:35 AM, Javier Herrero wrote: On 27.01.2014 15:08, Attila Kinali wrote: In practice, the receiver chip only has one power supply. It would take extra work to make the switching threshold below ground. That's not correct. Standard transceiver chips (like the MAX232 family) have an integrated charge pump to get a negative power supply. Hello, The venerable MC1489 does not need a negative supply, and can have a threshold below ground, without too much complication. http://www.onsemi.com/pub_link/Collateral/MC1489-D.PDF (the receiver circuit diagram is shown) On the other side, the MAX232 has positive thresholds in the receiver side http://datasheets.maximintegrated.com/en/ds/MAX220-MAX249.pdf pag. 6 Regards, Javier ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Trimble Thunderbolt 1pps
Specs or not. In real life most computers will accept a TTL level serial signal. They will also accept one with RS232 levels. The thing to keep straight is the RS232 uses negative logic for data, positive logic for control lines and TTL is always positive logic. You may need some inverters. So what to send? If the cable is 2 or 3 feet tit hardy matters. If the distance is moderate buy a Max232 chip and if the distance is far don't use RS232. moderate might go up to about 100 feet if you use quality cable. and don't route it in the ceiling over florescent lights and AC power lines. My solution was to buy a few of these DB9 connectors that have the MAX232 chip builtin. They cost about the same as normal connecters, find them on eBay. On Mon, Jan 27, 2014 at 6:08 AM, Attila Kinali att...@kinali.ch wrote: On Sun, 05 Jan 2014 13:35:43 -0800 Hal Murray hmur...@megapathdsl.net wrote: att...@kinali.ch said: Also keep in mind that RS-232 relies on the voltage going negative to encode a 1. I.e. getting 0V is not enough and might only work by chance with some RS-232 receivers. I think there are 2 parts to this discussion. What do the specs say, and what actually happens in the real world? I think the specs say that -3 to +3 is no mans land. A valid signal must be over +3 or under -3. IIRC that's right. But i haven't had a look at the standard for a very long time. In practice, the receiver chip only has one power supply. It would take extra work to make the switching threshold below ground. That's not correct. Standard transceiver chips (like the MAX232 family) have an integrated charge pump to get a negative power supply. I have never done exact measurements, but my experience is that going a bit (0.5V?) below GND and slightly more above GND is enough to get a proper 1/0 detection. Of course, if you rely on that you get a very poor noise performance. Attila Kinali -- The trouble with you, Shev, is you don't say anything until you've saved up a whole truckload of damned heavy brick arguments and then you dump them all out and never look at the bleeding body mangled beneath the heap -- Tirin, The Dispossessed, U. Le Guin ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Trimble Thunderbolt 1pps
Hi Javier, Our posts crossed. However the 1489 has a positive threshold (they call it turn off threshold) of 0.75 to 1.25V. They can be shifted to a negative trigger range using the response control pin but this is just a voltage divider and offset voltage, you still only get hysteresis of 1.1V for the A version. Interestingly the dataheet you linked to says the RS232D spec has a +/-3V threshold (6V hysteresis). I must have missed this or read a different version. I've still not seen a packaged receiver that meets this specification. Reobert G8RPI. From: Javier Herrero jherr...@hvsistemas.es To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Monday, 27 January 2014, 15:35 Subject: Re: [time-nuts] Trimble Thunderbolt 1pps On 27.01.2014 15:08, Attila Kinali wrote: In practice, the receiver chip only has one power supply. It would take extra work to make the switching threshold below ground. That's not correct. Standard transceiver chips (like the MAX232 family) have an integrated charge pump to get a negative power supply. Hello, The venerable MC1489 does not need a negative supply, and can have a threshold below ground, without too much complication. http://www.onsemi.com/pub_link/Collateral/MC1489-D.PDF (the receiver circuit diagram is shown) On the other side, the MAX232 has positive thresholds in the receiver side http://datasheets.maximintegrated.com/en/ds/MAX220-MAX249.pdf pag. 6 Regards, Javier ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Trimble Thunderbolt 1pps
On 27.01.2014 19:33, Robert Atkinson wrote: All the receiver chips I've looked at, ancient and modern, have only positive thresholds. Most have single supplies and clamp the input at 1 diode drop negative WRT common after an input current limiting resistor, see the MC1489 datasheet. Hello, Not exactly. If you check the MC1489 datasheet from On Semiconductor, the thresholds can be programmed with the response control resistor and can in fact be negative. (Figures 6 and 7 in the datasheet). The serial input resistor forms part of a resistive divider with the feedback resistor and the external resistor - not simply a current limiter to the diode. Regards, Javier ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Trimble Thunderbolt 1pps
On 2014-01-27 12:43, Javier Herrero wrote: On 27.01.2014 19:33, Robert Atkinson wrote: All the receiver chips I've looked at, ancient and modern, have only positive thresholds. Most have single supplies and clamp the input at 1 diode drop negative WRT common after an input current limiting resistor, see the MC1489 datasheet. Not exactly. If you check the MC1489 datasheet from On Semiconductor, the thresholds can be programmed with the response control resistor and can in fact be negative. (Figures 6 and 7 in the datasheet). The serial input resistor forms part of a resistive divider with the feedback resistor and the external resistor - not simply a current limiter to the diode. Recent device app notes state the spec is more or less the same, with TIA-232-F making some changes to conform to current versions of ITU V.24, V.28, and ISO 2110, restating the old speed/distance curves in terms of load capacitance 2500pF; output is still max +/-25V @ 100mA, rise/fall time 4% of bit time, up to 30V/us slew out of 300ohm impedance, input min +/-3V into 3k-7kohm 2500pF. Most recent adapters will work with only 0/3.3V over short cables at low speeds: higher speeds up to 115,200bpps require more drive and are limited to 3m, low speeds may work over 10m. Good luck finding any docs for these interface boards nowadays. YMMV should have been stamped on these specs since day one ;^ -- Take care. Thanks, Brian Inglis ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Trimble Thunderbolt 1pps
On 1/27/2014 1:33 PM, Robert Atkinson wrote: I looked at this a while ago. The spec only defines transmission levels, it does NOT specify receive thresholds. It certainly does... 2.1.3 For data interchange circuits, the signal shall be considered in the marking condition when the voltage on the interchange circuit, measured at the interface point, is more negative than -3 volts with respect to Circuit AB (Signal Common). The signal shall be considered in the spacing condition when the voltage is more positive than +3 volts with respect to Circuit AB (see 6.2). The region between +- 3 volts is defined as the transition region. The signal state is undefined when the voltage is in this transition region. - ANSI TIA/EIA-232-F (1997) ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Trimble Thunderbolt 1pps
we, maybe needed if you're running an ASR-33 teletype. . . Don Mike S On 1/27/2014 1:33 PM, Robert Atkinson wrote: I looked at this a while ago. The spec only defines transmission levels, it does NOT specify receive thresholds. It certainly does... 2.1.3 For data interchange circuits, the signal shall be considered in the marking condition when the voltage on the interchange circuit, measured at the interface point, is more negative than -3 volts with respect to Circuit AB (Signal Common). The signal shall be considered in the spacing condition when the voltage is more positive than +3 volts with respect to Circuit AB (see 6.2). The region between +- 3 volts is defined as the transition region. The signal state is undefined when the voltage is in this transition region. - ANSI TIA/EIA-232-F (1997) ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- The power of accurate observation is commonly called cynicism by those who have not got it. -George Bernard Shaw Dr. Don Latham AJ7LL Six Mile Systems LLC 17850 Six Mile Road POB 134 Huson, MT, 59846 VOX 406-626-4304 Skype: buffler2 www.lightningforensics.com www.sixmilesystems.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Trimble Thunderbolt 1pps
Hi, I'd already admitted my miss on that one in an earlier reply (don't know how i missed it but it was not a controlled copy of the spec ;-) . That not withstanding, show me a readily available receiver chip that actually meets that requirement. Most equipment that I've seen that would not work with 5V logic levels was failing to respond to the positive input level not the lack of a negative level. Ofteh this appeared to be caused by external circuitry, most likely intended for EMI/ESD/surge protection. From: Mike S mi...@flatsurface.com To: time-nuts@febo.com Sent: Tuesday, 28 January 2014, 2:01 Subject: Re: [time-nuts] Trimble Thunderbolt 1pps On 1/27/2014 1:33 PM, Robert Atkinson wrote: I looked at this a while ago. The spec only defines transmission levels, it does NOT specify receive thresholds. It certainly does... 2.1.3 For data interchange circuits, the signal shall be considered in the marking condition when the voltage on the interchange circuit, measured at the interface point, is more negative than -3 volts with respect to Circuit AB (Signal Common). The signal shall be considered in the spacing condition when the voltage is more positive than +3 volts with respect to Circuit AB (see 6.2). The region between +- 3 volts is defined as the transition region. The signal state is undefined when the voltage is in this transition region. - ANSI TIA/EIA-232-F (1997) ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Trimble Thunderbolt 1pps
I may have posted this link before. It is on topic, even though I was using coax cable: http://ko4bb.com/Test_Equipment/CoaxCableMatching.php It would be easy to do the same experiment with cat-5 cable. I would expect the pictures to look somewhat similar. Didier KO4BB Tom Van Baak t...@leapsecond.com wrote: Pulse quality of single-ended RS232 over unbalanced twisted pair is going to be pretty bad beyond a few feet. If you want to transport the 1pps over twisted pair there are a couple of options: Hi Brian, I suspect this is true at one level, but what would be helpful to to *quantify* it. What is pretty bad? What is few feet? You are implying that 1PPS timing is dependent in cable quality and cable length. I would agree. But please provide some numbers, even rough numbers, because what is important for modern TF applications (picoseconds and nanoseconds) can be irrelevant for NTP, which still lives in the millisecond and microsecond world. What I'd like to see, and what would be educational for the group, is if you could take some 'scope traces at a few inches, at a few feet, and at a few meters or tens of feet to graphically demonstrate your pont. My gut tells me 1 ns or 10 ns or 100 ns or 1 us or 10 us makes no measureable difference to the quality of NTP/PC timekeeping. /tvb ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- Sent from my Motorola Droid Razr 4G LTE wireless tracker while I do other things. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Trimble Thunderbolt 1pps
att...@kinali.ch said: Also keep in mind that RS-232 relies on the voltage going negative to encode a 1. I.e. getting 0V is not enough and might only work by chance with some RS-232 receivers. I think there are 2 parts to this discussion. What do the specs say, and what actually happens in the real world? I think the specs say that -3 to +3 is no mans land. A valid signal must be over +3 or under -3. In practice, the receiver chip only has one power supply. It would take extra work to make the switching threshold below ground. There is an additional quirk in here. The original Motorola MC1489 had a switching threshold of a diode drop (and some hysteresis). That chip was very popular and turned into a defacto standard. If you built a RS-232 receiver chip that required a negative input voltage, all sorts of obscure things would break and anybody who used it would have support nightmares. [1] The typical RS-232 receiver chips actually have good specs. In particular they spec the transition voltages in each direction. TI Data sheet for MC1489(A) and SN75189(A) http://www.ti.com/lit/ds/symlink/mc1489a.pdf TI Data sheet for MAX232 http://www.ti.com/lit/ds/symlink/max232.pdf --- Many years ago (early 1980s?), there was a popular brand of modems that sent out a TTL level rather than real RS-232 levels. Yes, we found that the hard way when we cut a corner. -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Trimble Thunderbolt 1pps
Interesting discussion re getting the 1PPS into a PC to synchronise a timing program. I use WSPR for ham radio and was wondering how to do this. Can you tell me which (Windows) time synch programs can use the 1PPS on DCD of the RS232 interface please? Next step would be to build a variable delay so I can trim the 1 PPS timing for those stations which are a little off-time and can't be decoded. thanks Zim Zim, I've found that the 3.3V level delivered by many modern GPS boards will work well enough with PC serial ports. If not, an inverter plus TTL-RS232 level converter will do the job, but I would try without first. NTP is the program I use for time sync, and it's never let me down. I use it on Windows, Linux and FreeBSD. You may find some useful information here: http://www.satsignal.eu/ntp/index.html You might also consider making your own stratum-1 NTP server with the low-cost Raspberry Pi - it works very well. I've used a variety of receivers both with the Pi and with Windows PCs. http://www.satsignal.eu/ntp/Raspberry-Pi-NTP.html http://www.satsignal.eu/ntp/Raspberry-Pi-NTP.html#GPS-devices 73, David GM8ARV -- SatSignal Software - Quality software written to your requirements Web: http://www.satsignal.eu Email: david-tay...@blueyonder.co.uk ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Trimble Thunderbolt 1pps
On Sat, Jan 4, 2014 at 12:36 AM, David J Taylor david-tay...@blueyonder.co.uk wrote: Interesting discussion re getting the 1PPS into a PC to synchronise a timing program. I use WSPR for ham radio and was wondering how to do this. Can you tell me which (Windows) time synch programs can use the 1PPS on DCD of the RS232 interface please? NTP is pretty much it. Most computers (likely including yours) already have NTP installed. You find it in routers and almost any device that connects to the Internet. But the version in Windows has been mess with by Microsoft. Get the real thing from www.ntp.org. It's free. One hint, you said time sync. The better way to understand NTP is rate sync. If it has to move the phase it will do it with a rate adjustment. NTP runs forever and tries to match the rate of your system clock to the best sources of time it has available and it will look at several of them. But in your case you will have only the one GPS. You will want to configure several internet timeservers to back up your GPS and serve as a sanity check on it. -- Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Trimble Thunderbolt 1pps
Since I had a couple of spare RS-232 driver gates, I built a simple PPS extender/level shifter in my Thunderbolt Monitor kit. It is not as general purpose (not configurable) as the Fat PPS kit from TAPR, but it works well for the Thunderbolt. You could easily build the circuit on a piece of perf board using the DIP version of the chip. Didier KO4BB WWW.KO4BB.com Hal Murray hmur...@megapathdsl.net wrote: Does the Trimble Thunderbolt provide 1pps on DCD of the RS232 interface? No, but you can open it up and add a wire. That will give you CMOS rather than RS232, but it works. (Or at least, it works for me and I've never heard a good story where it didn't work.) One problem is that the PPS signal is narrow. Some PCs may not be able to catch it. You can use the FatPPS from TAPR: http://www.tapr.org/kits_fatpps.html (It needs power. You can probably find that in the TBolt. I haven't done it.) I added a diode and R/C. That was good enough for the PC I was using. -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- Sent from my Motorola Droid Razr 4G LTE wireless tracker while I do other things. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Trimble Thunderbolt 1pps
albertson.ch...@gmail.com said: Where those using the cat-5 wire as a twisted pair? If sothat's cheating Yes. I was thinking that 4 pairs would be Rx, Tx, PPS, and power. If I need Ethernet, I'll pull another Cat-5. -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Trimble Thunderbolt 1pps
On Sat, Jan 4, 2014 at 12:05 PM, Hal Murray hmur...@megapathdsl.net wrote: albertson.ch...@gmail.com said: Where those using the cat-5 wire as a twisted pair? If sothat's cheating Yes. I was thinking that 4 pairs would be Rx, Tx, PPS, and power. If I need Ethernet, I'll pull another Cat-5. Pulse quality of single-ended RS232 over unbalanced twisted pair is going to be pretty bad beyond a few feet. If you want to transport the 1pps over twisted pair there are a couple of options: 1. A BALUN. There are lots of 75ohm-to-CAT5 BALUNs out there specifically for transporting NTSC video over CAT-5. At the far end use another BALUN before running into a TTL-to-RS232 line driver. There should be sufficient drive without too much extra hardware. (Terminate into 75 ohms tho'.) 2. Use an RS-422 driver. This will accept the TTL-level 1pps in and produce a nice differential output to drive the twisted pair. You can find serial cards that have RS-422 line receivers that will plug directly into the PC. 3. Simply use coax that is properly terminated at the far end to drive a TTL-to-RS232 line driver right at the computer's RS-232 input. All three of these should result in an acceptable 1pps with jitter levels lower than the timing resolution of the NTP server you are running on the target machine. -- Brian Lloyd, WB6RQN/J79BPL 706 Flightline Drive Spring Branch, TX 78070 br...@lloyd.com +1.916.877.5067 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Trimble Thunderbolt 1pps
The RIPE ntp system does a little bit of this. http://www.eecis.udel.edu/~mills/ntp/html/drivers/driver43.html -- Björn div Originalmeddelande /divdivFrån: Brian Lloyd br...@lloyd.com /divdivDatum:2014-01-04 19:26 (GMT+01:00) /divdivTill: Discussion of precise time and frequency measurement time-nuts@febo.com /divdivRubrik: Re: [time-nuts] Trimble Thunderbolt 1pps /divdiv /divOn Sat, Jan 4, 2014 at 12:05 PM, Hal Murray hmur...@megapathdsl.net wrote: albertson.ch...@gmail.com said: Where those using the cat-5 wire as a twisted pair? If sothat's cheating Yes. I was thinking that 4 pairs would be Rx, Tx, PPS, and power. If I need Ethernet, I'll pull another Cat-5. Pulse quality of single-ended RS232 over unbalanced twisted pair is going to be pretty bad beyond a few feet. If you want to transport the 1pps over twisted pair there are a couple of options: 1. A BALUN. There are lots of 75ohm-to-CAT5 BALUNs out there specifically for transporting NTSC video over CAT-5. At the far end use another BALUN before running into a TTL-to-RS232 line driver. There should be sufficient drive without too much extra hardware. (Terminate into 75 ohms tho'.) 2. Use an RS-422 driver. This will accept the TTL-level 1pps in and produce a nice differential output to drive the twisted pair. You can find serial cards that have RS-422 line receivers that will plug directly into the PC. 3. Simply use coax that is properly terminated at the far end to drive a TTL-to-RS232 line driver right at the computer's RS-232 input. All three of these should result in an acceptable 1pps with jitter levels lower than the timing resolution of the NTP server you are running on the target machine. -- Brian Lloyd, WB6RQN/J79BPL 706 Flightline Drive Spring Branch, TX 78070 br...@lloyd.com +1.916.877.5067 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Trimble Thunderbolt 1pps
Pulse quality of single-ended RS232 over unbalanced twisted pair is going to be pretty bad beyond a few feet. If you want to transport the 1pps over twisted pair there are a couple of options: Hi Brian, I suspect this is true at one level, but what would be helpful to to *quantify* it. What is pretty bad? What is few feet? You are implying that 1PPS timing is dependent in cable quality and cable length. I would agree. But please provide some numbers, even rough numbers, because what is important for modern TF applications (picoseconds and nanoseconds) can be irrelevant for NTP, which still lives in the millisecond and microsecond world. What I'd like to see, and what would be educational for the group, is if you could take some 'scope traces at a few inches, at a few feet, and at a few meters or tens of feet to graphically demonstrate your pont. My gut tells me 1 ns or 10 ns or 100 ns or 1 us or 10 us makes no measureable difference to the quality of NTP/PC timekeeping. /tvb ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Trimble Thunderbolt 1pps
On Sat, Jan 4, 2014 at 1:51 PM, Tom Van Baak t...@leapsecond.com wrote: Pulse quality of single-ended RS232 over unbalanced twisted pair is going to be pretty bad beyond a few feet. If you want to transport the 1pps over twisted pair there are a couple of options: Hi Brian, I suspect this is true at one level, but what would be helpful to to *quantify* it. What is pretty bad? What is few feet? You are implying that 1PPS timing is dependent in cable quality and cable length. I would agree. But please provide some numbers, even rough numbers,... OK, in this use case it is easy to divide good for bad. Bad means it does not work. I could not get interrupts to trigger. That is poor timing. If they reliably trigger then for NTP the details past that hardly matter. NTP can have very good timing using even not some good jitter on the clock because it looks at many clock poses over many minutes. Also on most PCs the time stamp resolution is one microsecond with about 2uSec accuracy. The shape of a PPS pulse does not matter, but they DO have to get to the PC and trigger an interrupt. If you only have a four wire cable, you are NOT using balanced pairs. For me, sending t/l level serial over 60+ feet of install cat-5 cable did not even result in reliable data transfer. Bosting the levels to RS-232 worked much better. Looking at waveforms on a scope using different lentghs of cable, will NOT be very instructive. Because in the real world a 100 foot cable is installed inside a wall and ceiling next to all kinds of real-life things also found in walls and ceilings, like fluorescent lights, other data cables, AC mains wire and whatever. You'd get real clean signals looking at wire in a lab. But in a real cable the result might depend on the HVAC cycle or if it is day or night. -- Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Trimble Thunderbolt 1pps
On Sat, Jan 4, 2014 at 3:51 PM, Tom Van Baak t...@leapsecond.com wrote: Pulse quality of single-ended RS232 over unbalanced twisted pair is going to be pretty bad beyond a few feet. If you want to transport the 1pps over twisted pair there are a couple of options: Hi Brian, I suspect this is true at one level, but what would be helpful to to *quantify* it. What is pretty bad? What is few feet? You are implying that 1PPS timing is dependent in cable quality and cable length. I would agree. But please provide some numbers, even rough numbers, because what is important for modern TF applications (picoseconds and nanoseconds) can be irrelevant for NTP, which still lives in the millisecond and microsecond world. Oh, called on the carpet I am! ;-) Very good point. More to the point would probably be protection, isolation, noise pick-up, ground noise, etc., for a long run. RS-232 is pretty susceptible to noise, hence my recommendations. And what might work for one person might not for another. But here is the point -- there is the concept of Best Engineering Practice. There are lots of things you can get away with most of the time but they are a bad idea to do as a general thing. Using an RS-232 signal over any distance at all is one of those bad things. It has poor noise immunity and when you are trying to catch the leading edge of a pulse it just isn't going to do very well. Or maybe it will be just fine ... until you are counting on it. Or maybe you have a transmitter around. What I'd like to see, and what would be educational for the group, is if you could take some 'scope traces at a few inches, at a few feet, and at a few meters or tens of feet to graphically demonstrate your point. I suppose I could. And what would be the advantage of that? Just because it can be made to appear relatively good in controlled environment still doesn't make its use valid. My situation is not yours. I am not operating in the same EM field you are. I have no idea what kind of ground-loop you are going to create and I am not (or vice versa). So, the key point is, and remains valid: RS-232 is a poor means to transmit signals over more than a relatively few feet. Sometimes it works great. Other times it won't work at all. If you want to transport a pulse over any distance the right answer is coax or a differential signal, e.g. RS-422. My gut tells me 1 ns or 10 ns or 100 ns or 1 us or 10 us makes no measureable difference to the quality of NTP/PC timekeeping. And my gut, based on designing data communications equipment, is that it is poor engineering practice. -- Brian Lloyd, WB6RQN/J79BPL 706 Flightline Drive Spring Branch, TX 78070 br...@lloyd.com +1.916.877.5067 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Trimble Thunderbolt 1pps
Does the Trimble Thunderbolt provide 1pps on DCD of the RS232 interface? -- Brian Lloyd, WB6RQN/J79BPL 706 Flightline Drive Spring Branch, TX 78070 br...@lloyd.com +1.916.877.5067 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Trimble Thunderbolt 1pps
No. The serial port is just three wires, the PPS signal is TTL level on one of the BNC connectors.You will have to level sift it to re-232 voltage levels and then make a costom cable On Fri, Jan 3, 2014 at 7:50 AM, Brian Lloyd br...@lloyd.com wrote: Does the Trimble Thunderbolt provide 1pps on DCD of the RS232 interface? -- Brian Lloyd, WB6RQN/J79BPL 706 Flightline Drive Spring Branch, TX 78070 br...@lloyd.com +1.916.877.5067 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Trimble Thunderbolt 1pps
On Fri, Jan 3, 2014 at 11:35 AM, Chris Albertson albertson.ch...@gmail.comwrote: No. The serial port is just three wires, the PPS signal is TTL level on one of the BNC connectors.You will have to level sift it to re-232 voltage levels and then make a costom cable Thank you. No problem. Just seemed like a logical thing they might have done for less-critical timing. -- Brian Lloyd, WB6RQN/J79BPL 706 Flightline Drive Spring Branch, TX 78070 br...@lloyd.com +1.916.877.5067 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Trimble Thunderbolt 1pps
Does the Trimble Thunderbolt provide 1pps on DCD of the RS232 interface? No, but you can open it up and add a wire. That will give you CMOS rather than RS232, but it works. (Or at least, it works for me and I've never heard a good story where it didn't work.) One problem is that the PPS signal is narrow. Some PCs may not be able to catch it. You can use the FatPPS from TAPR: http://www.tapr.org/kits_fatpps.html (It needs power. You can probably find that in the TBolt. I haven't done it.) I added a diode and R/C. That was good enough for the PC I was using. -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Trimble Thunderbolt 1pps
The TTL level PPS did not work for me when I tried to drive a long cable. I used the MAX232 level converter chip to level shift. Do check the polarity. If you get it wrong it will appear to work but the timing will biased by the pulse width. (the falling edges is used if you get it wrong. RS-232 levels are backwards from TTL except control signals. Just be sure you have the correct number of inverter. Then when you are done check the time is right. Being off by the pulse width in itself may not be bad because you can compensate in the software with a fudge parameter in the .conf file. But I wonder if the pulse width is well controlled. Do they use a one-shot or an RC circuit? Or do they count clock cycles based on the 10MHz clock? I don't know, safer to just use the leading edge. On Fri, Jan 3, 2014 at 11:30 AM, Hal Murray hmur...@megapathdsl.net wrote: Does the Trimble Thunderbolt provide 1pps on DCD of the RS232 interface? No, but you can open it up and add a wire. That will give you CMOS rather than RS232, but it works. (Or at least, it works for me and I've never heard a good story where it didn't work.) One problem is that the PPS signal is narrow. Some PCs may not be able to catch it. You can use the FatPPS from TAPR: http://www.tapr.org/kits_fatpps.html (It needs power. You can probably find that in the TBolt. I haven't done it.) I added a diode and R/C. That was good enough for the PC I was using. -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Trimble Thunderbolt 1pps
albertson.ch...@gmail.com said: The TTL level PPS did not work for me when I tried to drive a long cable. I used the MAX232 level converter chip to level shift. Thanks. How long was the cable? How solid was the driver? (How much of the problem was long cable vs weak driver?) -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Trimble Thunderbolt 1pps
The line driver was a TTL inverter chip I was going through about 50 or 60 feet of cat-5 wire. TTL level serial is always marginal, the specs say it should not work but it does work most of the time. I found a soave of DB9 connectors that have built-in MAX232 chips on ebay for under $5. I use these now in place of the normal DB9 on projects. On Fri, Jan 3, 2014 at 1:41 PM, Hal Murray hmur...@megapathdsl.net wrote: albertson.ch...@gmail.com said: The TTL level PPS did not work for me when I tried to drive a long cable. I used the MAX232 level converter chip to level shift. Thanks. How long was the cable? How solid was the driver? (How much of the problem was long cable vs weak driver?) -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Trimble Thunderbolt 1pps
On Fri, 3 Jan 2014 13:12:52 -0800 Chris Albertson albertson.ch...@gmail.com wrote: The TTL level PPS did not work for me when I tried to drive a long cable. I used the MAX232 level converter chip to level shift. Do check the polarity. If you get it wrong it will appear to work but the timing will biased by the pulse width. (the falling edges is used if you get it wrong. RS-232 levels are backwards from TTL except control signals. Just be sure you have the correct number of inverter. Then when you are done check the time is right. Also keep in mind that RS-232 relies on the voltage going negative to encode a 1. I.e. getting 0V is not enough and might only work by chance with some RS-232 receivers. Attila Kinali -- I pity people who can't find laughter or at least some bit of amusement in the little doings of the day. I believe I could find something ridiculous even in the saddest moment, if necessary. It has nothing to do with being superficial. It's a matter of joy in life. -- Sophie Scholl ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Trimble Thunderbolt 1pps
albertson.ch...@gmail.com said: The line driver was a TTL inverter chip I was going through about 50 or 60 feet of cat-5 wire. TTL level serial is always marginal, the specs say it should not work but it does work most of the time. Modern CMOS chips work much better than real TTL. Some CMOS chips have weak drivers. Cat-5 should be fine for 100 ft. Here are scope pictures from the PPS signal from a TBolt driving 100 feet of various types of wire: http://www.megapathdsl.net/~hmurray/time-nuts/coax/Coax-20ns.png http://www.megapathdsl.net/~hmurray/time-nuts/coax/TP-20ns.png The clump on the left of each graph is the input. The stuff on the right is the output. The scatter is due to the different prop times. -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Trimble Thunderbolt 1pps
Hal, Your plots don't show the wave being reflected by the cable end, and bouncing back and forth.. Until settling down. Without an end-termination the improperly terminated output of the Thunderbolt will cause the signal to bounce back and forth.. If there is a 50 ohms termination, there won't be any bounces, but a large voltage drop will happen due to the relatively high DC current over the long cable resistance.. (5V into 50 Ohms = 100mA). Maybe thats why the levels at the end are so much lower that at the source? Bye, Said Sent From iPhone On Jan 3, 2014, at 15:26, Hal Murray hmur...@megapathdsl.net wrote: albertson.ch...@gmail.com said: The line driver was a TTL inverter chip I was going through about 50 or 60 feet of cat-5 wire. TTL level serial is always marginal, the specs say it should not work but it does work most of the time. Modern CMOS chips work much better than real TTL. Some CMOS chips have weak drivers. Cat-5 should be fine for 100 ft. Here are scope pictures from the PPS signal from a TBolt driving 100 feet of various types of wire: http://www.megapathdsl.net/~hmurray/time-nuts/coax/Coax-20ns.png http://www.megapathdsl.net/~hmurray/time-nuts/coax/TP-20ns.png The clump on the left of each graph is the input. The stuff on the right is the output. The scatter is due to the different prop times. -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Trimble Thunderbolt 1pps
saidj...@aol.com said: Your plots don't show the wave being reflected by the cable end, and bouncing back and forth.. Until settling down. Yes. I'll put up some nasty pictures if anybody wants an ugly example. For that set of graphs, I tried to get rid of that sort of junk. I was working on the bench, using connectors and clipleads rather than PCBs or soldering whatever so things could be (much?) cleaner. For the coax, there was a short chunk of coax from the TBolt to a Tee at the scope, then the long chunk of coax under test, then a 50 ohm terminator at the other scope input. You can see some ringing due to the coax not really matching the terminator. For the twisted pairs, I used clipleads. The first/simple try wasn't good enough. The non-twisted cliplead wires were long enough to cause visible cruft. I ended up with a BNC to cliplead adapter with wires that were only 6 inches long. At the far end, I had a resistor merged into the clipleads, and adjusted it for best results. For the Cat-5 and Cat-6, I used a pair of RJ-45 to DB-9 adapters without the DB-9 connector. The wires coming out of the adapers are about 2 inches long. I forget what I did for the RG-6 which is 75 ohms. I have a pair of 50-75 adapters, but I don't remember doing any scaling to get the graphs to come out right and I don't see anything in the gnuplot commands to make the graphs. So I probably use a cliplead setup like for the twisted pairs. -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Trimble Thunderbolt 1pps
Hi Hal, still pretty impressive results, thanks for sharing the data. bye, Said In a message dated 1/3/2014 17:10:13 Pacific Standard Time, hmur...@megapathdsl.net writes: saidj...@aol.com said: Your plots don't show the wave being reflected by the cable end, and bouncing back and forth.. Until settling down. Yes. I'll put up some nasty pictures if anybody wants an ugly example. For that set of graphs, I tried to get rid of that sort of junk. I was working on the bench, using connectors and clipleads rather than PCBs or soldering whatever so things could be (much?) cleaner. For the coax, there was a short chunk of coax from the TBolt to a Tee at the scope, then the long chunk of coax under test, then a 50 ohm terminator at the other scope input. You can see some ringing due to the coax not really matching the terminator. For the twisted pairs, I used clipleads. The first/simple try wasn't good enough. The non-twisted cliplead wires were long enough to cause visible cruft. I ended up with a BNC to cliplead adapter with wires that were only 6 inches long. At the far end, I had a resistor merged into the clipleads, and adjusted it for best results. For the Cat-5 and Cat-6, I used a pair of RJ-45 to DB-9 adapters without the DB-9 connector. The wires coming out of the adapers are about 2 inches long. I forget what I did for the RG-6 which is 75 ohms. I have a pair of 50-75 adapters, but I don't remember doing any scaling to get the graphs to come out right and I don't see anything in the gnuplot commands to make the graphs. So I probably use a cliplead setup like for the twisted pairs. -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Trimble Thunderbolt 1pps
Interesting discussion re getting the 1PPS into a PC to synchronise a timing program. I use WSPR for ham radio and was wondering how to do this. Can you tell me which (Windows) time synch programs can use the 1PPS on DCD of the RS232 interface please? Next step would be to build a variable delay so I can trim the 1 PPS timing for those stations which are a little off-time and can't be decoded. thanks Zim ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Trimble Thunderbolt 1pps
Can you tell me which (Windows) time synch programs can use the 1PPS on DCD of the RS232 interface please? To answer my own question: Here's one... http://www.visualgps.net/NMEATime/default.htm There are a few others listed at http://www.gpskit.nl/links-en.htm Zim ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Trimble Thunderbolt 1pps
On Fri, Jan 3, 2014 at 8:32 PM, Graeme Zimmer gzim...@wideband.net.auwrote: Can you tell me which (Windows) time synch programs can use the 1PPS on DCD of the RS232 interface please? To answer my own question: Here's one... http://www.visualgps.net/NMEATime/default.htm There are a few others listed at http://www.gpskit.nl/links-en.htm Zim ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/ mailman/listinfo/time-nuts and follow the instructions there. Unless you bring the 1pps in and synchronize with that, you are probably better off just running NTP. -- Brian Lloyd, WB6RQN/J79BPL 706 Flightline Drive Spring Branch, TX 78070 br...@lloyd.com +1.916.877.5067 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Trimble Thunderbolt 1pps
Where those using the cat-5 wire as a twisted pair? If sothat's cheating I was truing to send an RS232 signal down a cat 5 cable. That means Tx, Rx Gnd and DCD. You need four wires for that, ethernet uses the other two pair.I was using the pairs Ethernet does not use. The solution was to just not do it. I swapped out the entire system so that now the computer is a $20 ARM based NAS that I re-flashed moved physically close. Here are scope pictures from the PPS signal from a TBolt driving 100 feet of various types of wire: http://www.megapathdsl.net/~hmurray/time-nuts/coax/Coax-20ns.png http://www.megapathdsl.net/~hmurray/time-nuts/coax/TP-20ns.png The clump on the left of each graph is the input. The stuff on the right is the output. The scatter is due to the different prop times. -- Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Trimble Thunderbolt 1pps
Unless you bring the 1pps in and synchronize with that, you are probably better off just running NTP. Yes, that is the idea. I often don't have access to the Internet when running WSPR. eg when operating portable in remote areas or marine. Thanks . Zim ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Trimble Thunderbolt 1PPS TTL level?
On Fri, 29 Aug 2008 22:21:43 -0400, Pieter Ibelings wrote: Hi All, I got a Trimble Thunderbold from Ebay and I am having trouble triggering the HP 53131A. The 1PPS output shows a 10us pulse of 1 Volt into a high impedance probe. This seems low to me. Should it be 5 volts? Maybe the output 74AC04 is toast? Pieter, N4IP Hi Pieter, there is nothing to be worried about, I have the same problem with my 53132A, it does not trigger on it with 50 ohms or high impedance load. So I tried it with the 5334A - no problem at all ! It does trigger as expected, without any signal loss. Seem to be a problem of the 53131A/ 53132A series counter. regards, Arnold ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Trimble Thunderbolt 1PPS TTL level?
Arnold, Thanks. I had a dirty BNC connector so I am now getting 5 volts and 10us wide. I cannot get the counter to lock. There has to be a way of getting it to work. Regards, Pieter - Original Message - From: Arnold Tibus [EMAIL PROTECTED] To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Saturday, August 30, 2008 10:12 AM Subject: Re: [time-nuts] Trimble Thunderbolt 1PPS TTL level? On Fri, 29 Aug 2008 22:21:43 -0400, Pieter Ibelings wrote: Hi All, I got a Trimble Thunderbold from Ebay and I am having trouble triggering the HP 53131A. The 1PPS output shows a 10us pulse of 1 Volt into a high impedance probe. This seems low to me. Should it be 5 volts? Maybe the output 74AC04 is toast? Pieter, N4IP Hi Pieter, there is nothing to be worried about, I have the same problem with my 53132A, it does not trigger on it with 50 ohms or high impedance load. So I tried it with the 5334A - no problem at all ! It does trigger as expected, without any signal loss. Seem to be a problem of the 53131A/ 53132A series counter. regards, Arnold ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Trimble Thunderbolt 1PPS TTL level?
Hi All, I got a Trimble Thunderbold from Ebay and I am having trouble triggering the HP 53131A. The 1PPS output shows a 10us pulse of 1 Volt into a high impedance probe. This seems low to me. Should it be 5 volts? Maybe the output 74AC04 is toast? Pieter, N4IP ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Trimble Thunderbolt 1PPS TTL level?
Have you tried terminating it with 50ohms? That was the trick for mine. Scott Pieter Ibelings wrote: Hi All, I got a Trimble Thunderbold from Ebay and I am having trouble triggering the HP 53131A. The 1PPS output shows a 10us pulse of 1 Volt into a high impedance probe. This seems low to me. Should it be 5 volts? Maybe the output 74AC04 is toast? Pieter, N4IP ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
