Re: [time-nuts] Pack Rat GPS receiver project
Ben, I would like a copy of your code. I use the Pack Rat code, with display, and my Arduino seems to lock up after several hours of running. I have tried 2 different Arduino micro controllers, and they both freeze. I would like to try different code to see if that fixes it.Thanks,Steve On Tuesday, April 17, 2018, 5:05:49 PM MST, Ben Hallwrote: On 4/17/2018 5:12 PM, donandarl...@gmail.com wrote: > I’m looking for the Hex files for the Pack Rat GPS receiver project. > If any body has them, I sure would appreciate a copy. > I found an old post on here that showed Ben Hall had the code and would share > it with others off line > But I have no way to get hold of him. Good evening all! I just sent Don the two hex files. If anyone else would like a copy, feel free to holler at me off list. I'll even include the Arduino code I wrote from scratch (more or less) for the Trueposition units as long as you promise not to make too much fun of how awful it really is! ;) I am *not* a programmer...just a guy who wanted to play with Arduino and learn something which I did. thanks much and 73, ben, kd5byb ___ 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] X72 and 1pps
Matthias, I'm working on the same project. It looks like you should only be able to get the difference between the two 1pps signals out of the rs-232 port. Maybe Heather can display it? This is from the X72 designers reference manual "A 1 PPS output is an integral part of the design.An optional 1 PPS input allows the unit to track aGPS or other external reference, and display thedifference between the input and the 1 PPS generatedby the X72 through the RS232 link." "3.4.2 X72 1 PPS Input and OutputThe 1 PPS output signal of the X72 unit is positive edge triggered and gated with the rising edge ofthe clock. It’s duration for a 10 MHz unit is 400 ns ±10%. Rise/fall time is 4 ns.The 1 PPS is exactly divided from the XO frequency.Future implementation will support tracking, synching and smoothing of incoming 1 PPS toproduce the output 1 PPS." Stephan On Sunday, March 4, 2018 6:47 AM, Matthias Jelenwrote: Hi Mark, thanks for your reply. > Try enabling the PPS input form the "P menu. I can´t find this option - I can toggle the PPS output, but not the input. BTW, what´s the "set TIC" option? I can enter a number here, but I can´t find something about this command in the manual... Auto-Tune seems to work well - I see the plot stepping and a slope is calculated. What´s the expected behaviour if I go to d-e: "Enable HW discipline" ? I can´t see any changes here. I checked the SA.22.C manual as well, but this contains more or less the same information as the X72. Regards, Matthias > Also, to verify that it is using the PPS input try the auto-tune command. > It will set the TIC and DDS tune word to to 0, collect data for for however > long you requested (an hour is a good start), then calculate the drift rate > and set the DDS tune word to put the device on frequency. The EE command > should set save the DDS word in EEPROM. If the unit is seeing the PPS > input, you should see the PPS plot stepping as the DDS freq drifts. > > Many of the X72 settings cannot be read back from the unit. Heather > maintains a "software eeprom" with the settings that it knows about in the > file "tbeeprom.dat". Until you update a setting, what is displayed for that > setting may not be correct. Use the "P" menu to set each of the settings so > that Heather can learn what they are. When Heather starts up, it restores > all the last settings from the file. > ___ > 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] Symmetricom X72 interface boards
Mark,Got mine today. Looks great. Will test it on the weekend. Thanks for the good work.Steve On Wednesday, December 6, 2017 10:07 PM, Mark Simswrote: The X72 rubidium oscillator interface board sets have (finally) been shipped to everybody that paid for them. I had hoped to get them out a couple of weeks ago, but ran into a couple of annoying snags... First, the assembly house built a couple of test articles that were great and were approved for production. Over a week later they came back and said "They're ready... except we can't do the through hole parts. Our through-hole machine is broken and we aren't going to fix it" (turns out they sold the company assets to another company and were letting them deal with it). I wound up hand soldering them... lotsa fun there. Next, it turned out the the MAX232A RS-232 chips I got in were wonky / fake / haunted. Luckily they are socketed. I bought out the local supply of good / genuine ones. Ahh, such fun. If anybody needs 50 sketchy MAX232A's... I can hook you up. ___ 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] True Position Time Figure of Merit
Thank you Mark. I will read through it.Steve On Wednesday, October 18, 2017 4:01 AM, Mark Simswrote: This forum thread has most of our reverse engineering info on these GPSDO's: http://www.eevblog.com/forum/projects/gpsdo-loss-of-satellitesfix-troubleshooting/ ___ 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] True Position Time Figure of Merit
Hi,I have been trying out my True Position GPSDO, and I have a few questions. I have been running the survey for about 32 hours, and the figure of merit goes between 2 and 4, usually 3 or 4, (range of 1-7). I have been monitoring the frequency adjusting voltage, and it varies between 2.1800 and 2.1900 v( 0-4v range). My unit has the Bliley oscillator. Does it have to be doing a survey to adjust the frequency? Is this behavior normal? How long should I expect to wait for a figure of merit of one? Thanks,Steve ___ 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] True Position GPSDP + Rb X72
The True Position GPSDO is working, locked to 8 satellites. It's 10MHz output is extremely close to the X72's output. Using an oscilloscope to compare the signals with a lissajous pattern, there is only a very small, slow movement, barely perceivable. I don't need to do any calibration to the X72. Steve On Sunday, October 1, 2017 10:45 AM, Stephan Flor via time-nuts <time-nuts@febo.com> wrote: I figured it out. It was the ASCII settings, it's working now. - ASCII Sending, "Echo typed characters locally" - ASCII Receiving, "Append line feeds to incoming line ends" Thanks,Steve On Sunday, October 1, 2017 8:30 AM, Stephan Flor <spf...@yahoo.com> wrote: I received my True Position GPSDO. I'm testing it.I am connected to it via a rs232 port, and using HyperTerminal on a XP laptop to communicate. I'm getting the boot message "GETVER 12.0.1 BOOT". This may be a stupid question, but how do I get the boot message to stop so I can send the "$PROCEED" command? If I type while the message is scrolling, I have no courser, and no text appears on the screen. Thanks,Steve On Friday, September 29, 2017 5:32 PM, Attila Kinali <att...@kinali.ch> wrote: On Sun, 24 Sep 2017 01:06:36 -0400 ewkehren via time-nuts <time-nuts@febo.com> wrote: > Starting with a 10 second clean up loop for a FEI 5680/GPSDO to now 600 > Seconds using Wenzel's j circuit for the Tbolt we have a variety of boards. Which one is Wenzel's j circuit? Google does not seem to be able to find it. And going through relevant circuits on wenzel.com didnt reveal any j circuit. -- It is upon moral qualities that a society is ultimately founded. All the prosperity and technological sophistication in the world is of no use without that foundation. -- Miss Matheson, The Diamond Age, Neil Stephenson ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] True Position GPSDP + Rb X72
I figured it out. It was the ASCII settings, it's working now. - ASCII Sending, "Echo typed characters locally" - ASCII Receiving, "Append line feeds to incoming line ends" Thanks,Steve On Sunday, October 1, 2017 8:30 AM, Stephan Florwrote: I received my True Position GPSDO. I'm testing it.I am connected to it via a rs232 port, and using HyperTerminal on a XP laptop to communicate. I'm getting the boot message "GETVER 12.0.1 BOOT". This may be a stupid question, but how do I get the boot message to stop so I can send the "$PROCEED" command? If I type while the message is scrolling, I have no courser, and no text appears on the screen. Thanks,SteveOn Friday, September 29, 2017 5:32 PM, Attila Kinali wrote: On Sun, 24 Sep 2017 01:06:36 -0400 ewkehren via time-nuts wrote: > Starting with a 10 second clean up loop for a FEI 5680/GPSDO to now 600 > Seconds using Wenzel's j circuit for the Tbolt we have a variety of boards. Which one is Wenzel's j circuit? Google does not seem to be able to find it. And going through relevant circuits on wenzel.com didnt reveal any j circuit. -- It is upon moral qualities that a society is ultimately founded. All the prosperity and technological sophistication in the world is of no use without that foundation. -- Miss Matheson, The Diamond Age, Neil Stephenson ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] True Position GPSDP + Rb X72
I received my True Position GPSDO. I'm testing it.I am connected to it via a rs232 port, and using HyperTerminal on a XP laptop to communicate. I'm getting the boot message "GETVER 12.0.1 BOOT". This may be a stupid question, but how do I get the boot message to stop so I can send the "$PROCEED" command? If I type while the message is scrolling, I have no courser, and no text appears on the screen. Thanks,SteveOn Friday, September 29, 2017 5:32 PM, Attila Kinaliwrote: On Sun, 24 Sep 2017 01:06:36 -0400 ewkehren via time-nuts wrote: > Starting with a 10 second clean up loop for a FEI 5680/GPSDO to now 600 > Seconds using Wenzel's j circuit for the Tbolt we have a variety of boards. Which one is Wenzel's j circuit? Google does not seem to be able to find it. And going through relevant circuits on wenzel.com didnt reveal any j circuit. -- It is upon moral qualities that a society is ultimately founded. All the prosperity and technological sophistication in the world is of no use without that foundation. -- Miss Matheson, The Diamond Age, Neil Stephenson ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] True Position GPSDP + Rb X72
The highest frequency I can generate is 2.5 GHz. My counter can measure 20 GHz, to 1 HZ. At the moment I'm have a frequency locking problem with the extension module in my HP 8660C, so I can't even get to 2.5 GHz, only 110 MHz at the moment. I gust got some extender boards, so I hope to have it fixed soon. The X72 gives me a solid 10.00 MHz, I would like to see what I get when I use the Rb as a clock for the signal generator, at 2.5 GHz. I guess I only need to verify the calibration with the GPSDO, when I get it, and get it working. Then I can calibrate everything else. So, to make a long answer short, I don't think I need the level of accuracy that these devices are capable of. I just have a neurotic need to try and make things as exact as I possibly can. Also, this is just a hobby, and learning experience for me, so I can take my time to work things out.Thank you,Steve On Thursday, September 21, 2017 12:09 PM, Chris Caudlewrote: On Wed, September 20, 2017 3:44 pm, Stephan Flo via time-nuts wrote: > I just wanted a 10 MHz sync for my test equipment that was calibrated. > May be the GPSDO is all I need. Even an undisciplined rubidium oscillator is going to be very close to nominal 10MHz. You have never stated your desired precision that I have seen. The X72 manual says that the output should be within 1E-9 in under 10 minutes, and within 5E-11 after 30 minutes. Does any of the equipment you use have finer precision than that? -- Chris Caudle ___ 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] True Position GPSDP + Rb X72
Thank you for the great feedback. You guys make me realize that I need to learn more, I have some studying to do. I will study while I wait for the True position to arrive. Then I have to get it working. I just wanted a 10 MHz sync for my test equipment that was calibrated. May be the GPSDO is all I need. Steve On Wednesday, September 20, 2017 7:28 AM, Bob kb8tq <kb...@n1k.org> wrote: Hi > On Sep 20, 2017, at 8:39 AM, Attila Kinali <att...@kinali.ch> wrote: > > On Tue, 19 Sep 2017 18:09:16 + (UTC) > Stephan Flor via time-nuts <time-nuts@febo.com> wrote: > >> Hi everyone,I'm new to this list, and I wanted to get the opinion of some >> mere experienced people on my project idea.I just got a Symmetricom X72 Rb >> oscillator, and I have a True position GPSDO on the way. I wan't to have a >> self calibrating 10 MHz signal to synchronize my hobby rf lab equipment. >> My idea is to make a GPS disciplined Rubidium oscillator, by removing the >> crystal oscillator ans substituting the X72 in the GPSDO circuit.I would >> just >> have to make a op amp circuit to change the 0 to 4v correction signal from >> the True Position, to a 0 to 5v signal for the X72. > > Unfortunately, this doesn't work as easily as you thing. > The control loop inside the GPSDO is designed for an OCXO. This means > that its loop constant is in the 10s to 100s of seconds, while for > an GPSDRb you would need 10'000s to 100'000s of seconds. The other, > more criticial issue is the sensitivity of the tuning input. Most > OCXOs have something like 1-10ppm of tuning range. The tuning range > of an Rb is usually 2 to 3 orders of magnitude smaller. In a normal > PI loop, this shouldn't be an issue. But you don't know what the > internal logic does. So at least be careful with that. > > The more common way to build such a system is to do a phase comparison > between the 10MHz output of the GPSDO and the Rb, then steer the Rb > using a seperate control loop electronics. One easy way to do this > would be using a uC with a capture compare unit, at least one with 16bit, > better with 24bits and more (e.g. STM32F4xx). Divide both 10MHz outputs > down to roughly 1kHz-10kHz using 74LVC161. With this you can measure > the phase differnce between the two with about 12ns precision (limited > by the uC, not the dividers). Average over 2-3 days and you are good. An alternative is to add an offset oscillator to the mix and look at beat notes. It does not have to be ultra close. An 11 MHz offset signal would take the 12 ns down to an effective 1.2 ns. Odd frequency OCXO’s sell cheap on eBay. Bob > > For additional precision, you can use an TDC7200 to measure the time > difference with around 50-100ps precision, at which point the GPSDO > noise and the stability of the Rb will be the limiting elements. > > > Attila Kinali > > -- > It is upon moral qualities that a society is ultimately founded. All > the prosperity and technological sophistication in the world is of no > use without that foundation. > -- Miss Matheson, The Diamond Age, Neil Stephenson > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ 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] True Position GPSDP + Rb X72
Thank you Mark. I'm just starting to learn about Rb oscillators and GPSDO. I started on this while repairing my old HP 8660c signal generator, and I wanted to get all of my equipment on a common sync clock. I bought the X72, because it was small, thinking I may be able to replace the ocxo in the 8660c with it. Now I regret wasting $100 on the X72. I will download Lady Heather and see what I can do with it, while I wait for my True Position to arrive. Thank you,Steve On Wednesday, September 20, 2017 11:18 AM, Mark Simswrote: GPS disciplined rubidium oscillators are generally not a good idea. Rubidiums tend to be quite a bit more noisy than OCXOs. Their advantage is their long term frequency stability. The GPS system in a GPSDO compensates for the OCXO drift, so the only advantage of a GPS disciplined Rb is if you lose the GPS signal for a long time. Also, remember Mark's Law of Rubidium Oscillators... the small the oscillator, the crappier it is. The X72 is a very small Rb oscillator and , guess what, it's rather crappy. Noisy, temperature sensitive, not all that good frequency stability. A decent OCXO can out-perform it. Lady Heather now supports the X72 (and SA22.c). It has a disciplining routine that can lock it to a 1PPS input. It uses the X72's built in time interval counter that has a 16.667 ns resolution (due to noise and synchronizing issues more like 33 ns). Later firmware versions of the X72 and SA22.c have a built in 1PPS disciplining routine, but I am not too impressed with it. It seems rather temperamental (or just plain mental) and I have seen it go off into la-la land and refuse to lock. ___ 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] True Position GPSDP + Rb X72
Hi everyone,I'm new to this list, and I wanted to get the opinion of some mere experienced people on my project idea.I just got a Symmetricom X72 Rb oscillator, and I have a True position GPSDO on the way. I wan't to have a self calibrating 10 MHz signal to synchronize my hobby rf lab equipment. My idea is to make a GPS disciplined Rubidium oscillator, by removing the crystal oscillator ans substituting the X72 in the GPSDO circuit.I would just have to make a op amp circuit to change the 0 to 4v correction signal from the True Position, to a 0 to 5v signal for the X72. The X72 seems to work well, 10.00 MHz on my HP 5350B, last calibrated by the US Navy in 1994. I just ordered the True position, from China, so I won't see that for a while, then I need to get it working. What do you think? Good idea or waste of time? Will the True Position software be able to cope with the change? I haven't done any programming is at least 20 years, so, I hope I can do this with hard ware. Also, does anyone have ideas for a low cost 10 MHz 50 ohm distribution amp? Thanks,Steve ___ 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.