[time-nuts] Re: Web/Mobile Apps Development no cost
Hello, I'm just checking with you to see if you're interested in redesigning or upgrading your mobile application, or if you're interested in building a whole new mobile application completely. If you Looking for ready-made e-commerce, Delivery, Dating website-mobile Application/ERP solution to save time & cost... so plz let me know? If so, I'd love to tell you a little bit more about my abilities and show you some of my work. I am a very skilled mobile application designer with various abilities and can develop anything. I look forward to hearing from you. Thanks ___ 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: Phase Station 53100A Questions
> I think you may be heading a bit off track digging into the 5120. The > 53100a has a very different “heritage” than the TSC gear. The 5330 > “TimePod” would be a better thing to dig into to see its history. I’m > guessing 52100A is a typo. > > The .TIM files are generated by TimeLab so that’s a good place to look > for grubby details of this or that. They are “just” text files with a lot of > embeded comments that document what’s what on each line. Maybe > not *quite* a “just read it and it all makes sense”, but there is a lot of > information in the file itself. I would suggest starting by reading through > the file that TimeLab puts out. What Bob says. :) It's true that the .TIM file format is meant to be self-descriptive to some extent, but it's also true that we really ought to document it formally at some point. I've been holding off for the next major revision of the file format, which is intended to support multichannel measurements and per-sample metadata in a single file. That will probably be an extensive-enough overhaul to render existing documentation obsolete. That said, feel free to email me -- or post here -- if you have questions. > 2. There will be some debugging required in my test setup, and it > would be very useful if I could independently demodulate the > Amplitude Modulation (AM) and Phase Modulation (PM) components of the > phase noise, and present the low-passed waveforms in voltage versus > time form. Signals leaking in for other places may well be > recognizable by resemblance of the demodulated AM or PM baseband > waveform to other signals known to exist in the system under test. I > was thinking that the TIM file may be a start. This would really need to be addressed with direct access to the I/Q data stream from the hardware, which isn't on the road map right now. If the goal is to track down signal leakage, though, it is very effective to look at the AM and/or PM spurs, and also the frequency-difference view. As long as you select a measurement bandwidth that's wide enough to include the source(s) of concern, they will show up as periodic artifacts in frequency difference measurements as well as ripple in the ADEV trace. As far as the fundamental principles of operation go, they are covered reasonably well in the manual. Again, any specific questions, just say the word. The TSC patents are mostly aimed at working around deficiencies in the early RF ADC chips and DDS IP cores that were available when Sam Stein's team did the original groundwork. I wouldn't say they're a waste of time to study, but they are of historical rather than operational interest. As a source for further reading, the 5120A/5125A manuals are likely to be more helpful than the patents. -- john (TimeLab support guy) ___ 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: Phase Station 53100A Questions
Hi I think you may be heading a bit off track digging into the 5120. The 53100a has a very different “heritage” than the TSC gear. The 5330 “TimePod” would be a better thing to dig into to see its history. I’m guessing 52100A is a typo. The .TIM files are generated by TimeLab so that’s a good place to look for grubby details of this or that. They are “just” text files with a lot of embeded comments that document what’s what on each line. Maybe not *quite* a “just read it and it all makes sense”, but there is a lot of information in the file itself. I would suggest starting by reading through the file that TimeLab puts out. Bob > On Feb 9, 2022, at 1:43 PM, Joseph Gwinn wrote: > > I will be doing some residual phase noise tests in a month or so > using a 53100A Phase Noise Analyzer (not yet in hand), so I've been > studying the users manual and datasheet of the Microchip 52100A Phase > Noise Analyzer. I do know the history, starting with Sam Stein > developing the Timing Solutions Corp (TSC) model 5120. > > Anyway, some questions have arisen: > > 1. Where is the ".TIM" file format documented? Google fails here, > chasing after some other kinds of .TIM file unrelated to the 5120 and > descendants. The 53100A users manual does not define the .TIM file > format, or say where to find it. > > 2. There will be some debugging required in my test setup, and it > would be very useful if I could independently demodulate the > Amplitude Modulation (AM) and Phase Modulation (PM) components of the > phase noise, and present the low-passed waveforms in voltage versus > time form. Signals leaking in for other places may well be > recognizable by resemblance of the demodulated AM or PM baseband > waveform to other signals known to exist in the system under test. I > was thinking that the TIM file may be a start. > > 3. Where are the fundamental Principles of Operation documented? > The best I've found so far is a pair of patents by Wayne Solbrig, > US7227346 (Two channel digital phase detector) and US7436166 (Direct > digital synthesizer producing a signal representing an amplitude of a > sine wave), both originally assigned to TSC, and now expired. > > Thanks, > > Joe Gwinn > ___ > 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: Phase Station 53100A Questions
Hi Joe -- The TimeLab software that's used with the 53100A is available from John Miles at http://www.miles.io/timelab/beta.htm. There is a pretty comprehensive users guide as well as a couple of app notes there, although I don't think any of them document the .TIM file format. However, he provides the TimeLab source code so it should be discernable from there. John On 2/9/22 1:43 PM, Joseph Gwinn wrote: I will be doing some residual phase noise tests in a month or so using a 53100A Phase Noise Analyzer (not yet in hand), so I've been studying the users manual and datasheet of the Microchip 52100A Phase Noise Analyzer. I do know the history, starting with Sam Stein developing the Timing Solutions Corp (TSC) model 5120. Anyway, some questions have arisen: 1. Where is the ".TIM" file format documented? Google fails here, chasing after some other kinds of .TIM file unrelated to the 5120 and descendants. The 53100A users manual does not define the .TIM file format, or say where to find it. 2. There will be some debugging required in my test setup, and it would be very useful if I could independently demodulate the Amplitude Modulation (AM) and Phase Modulation (PM) components of the phase noise, and present the low-passed waveforms in voltage versus time form. Signals leaking in for other places may well be recognizable by resemblance of the demodulated AM or PM baseband waveform to other signals known to exist in the system under test. I was thinking that the TIM file may be a start. 3. Where are the fundamental Principles of Operation documented? The best I've found so far is a pair of patents by Wayne Solbrig, US7227346 (Two channel digital phase detector) and US7436166 (Direct digital synthesizer producing a signal representing an amplitude of a sine wave), both originally assigned to TSC, and now expired. Thanks, Joe Gwinn ___ 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] Phase Station 53100A Questions
I will be doing some residual phase noise tests in a month or so using a 53100A Phase Noise Analyzer (not yet in hand), so I've been studying the users manual and datasheet of the Microchip 52100A Phase Noise Analyzer. I do know the history, starting with Sam Stein developing the Timing Solutions Corp (TSC) model 5120. Anyway, some questions have arisen: 1. Where is the ".TIM" file format documented? Google fails here, chasing after some other kinds of .TIM file unrelated to the 5120 and descendants. The 53100A users manual does not define the .TIM file format, or say where to find it. 2. There will be some debugging required in my test setup, and it would be very useful if I could independently demodulate the Amplitude Modulation (AM) and Phase Modulation (PM) components of the phase noise, and present the low-passed waveforms in voltage versus time form. Signals leaking in for other places may well be recognizable by resemblance of the demodulated AM or PM baseband waveform to other signals known to exist in the system under test. I was thinking that the TIM file may be a start. 3. Where are the fundamental Principles of Operation documented? The best I've found so far is a pair of patents by Wayne Solbrig, US7227346 (Two channel digital phase detector) and US7436166 (Direct digital synthesizer producing a signal representing an amplitude of a sine wave), both originally assigned to TSC, and now expired. Thanks, Joe Gwinn ___ 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] Looking to purchase an HP 5065A
Hello, I'm interested in purchasing a (preferably working) HP 5065A. I've kept my eyes out on Ebay for a unit but no luck so far. If anyone has one they'd be willing to part with please let me know! Matt ___ 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: Help needed IDing GPS antenna
Looks like an Aeroantenna OEM device. May be a https://www.aeroantenna.com/PDF/AT7530-1_B.pdf The marine style antennae tend to be lower in gain (I assume because the downlead is much shorter), so could be 12dB gain and 5V power. Philip -- Forwarded message - From: John Miller via time-nuts Date: Tue, Feb 8, 2022 at 7:37 PM Subject: [time-nuts] Help needed IDing GPS antenna To: Cc: John Miller Hey all, I'm looking for a specs sheet for an antenna i recently got my hands on. It's marked Topcon on the top, II Morrow Inc model 590-1114 on the bottom. I've tried searching in all the usual places but haven't found anything yet. If anyone could send anything my way that would be much appreciated! Some pictures here: https://photos.millerjs.org/?f=Topcon+Antenna Thanks, 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: Garmin GPS 25 Module
Hi I would suggest that killing off anything that’s unused is a really good idea, especially when switching to a new module. You eliminate a lot of weird corner case issues that you *really* don’t want to find out about …. Bob > On Feb 9, 2022, at 10:57 AM, Andy Talbot wrote: > > Yes, I had to disable the GSV sentence to get the data flow down to a level > that could be sent at the lower speed. > I'm only using GPRMC, so all the others could be removed as well, but as > GPRMC comes first in the block every second, there's nothing to be gained > from killing any of the others sentences. > > I did fall foul once of a changed format. Originally I wrote for an RMC > string that just gave integer seconds. On using my code with a later > module it failed, and I spotted that it was sending decimal seconds, so had > to rewrite my PIC code to cope with that. > Then later, using other module types, GPRMC became GNRMC to cope with > Glonass etc. so that was another change needed. > > Andy > www.g4jnt.com > > > > On Wed, 9 Feb 2022 at 15:49, Bob kb8tq wrote: > >> Hi >> >> In terms of upgrading the GPS module(s): >> >> You might want to look at just *what* NMEA messages are being used. >> While the format is “standard” it’s not quite dead nuts in some cases. >> Vendors get to add this and that and it still is NMEA. Converting from >> one family to another is not always easy. >> >> I would also want to check the GPS antenna at the remote site. They >> don’t last forever. Flakey sat signals can drive a module a bit nuts. >> >> GPS modules have gotten pretty cheap over the years. If this is a long >> drive / crazy access sort of thing, redundancy is not as expensive on >> the module (or antenna) side as it once was. >> >> Bob >> >>> On Feb 9, 2022, at 4:36 AM, Andy Talbot wrote: >>> >>> I run a set of microwave beacons on a remote site that transmit data >> modes >>> whose Tx timing is controlled from GPS. They were installed some 20 >> years >>> ago and used a Garmin GPS25-LVS module to deliver NMA and 1 PPS signals >> to >>> all five individual controllers. >>> >>> After a power outage that lasted a couple of days, the beacons fired up >> but >>> it was clear, after a couple of days timing was corrupted. Each beacon >> has >>> slightly different controller firmware, and by monitoring the resulting >>> corrupted modulation it could be determined what was wrong.No PPS >>> signal was present - which killed modulation on two of them. NMEA timing >>> data was present but the time being reported was out by several seconds, >>> rendering the data signal transmitted undecodable by most people. >>> >>> I went up to the remote site to recover the old hardware and am in the >>> process of replacing the timing source using a Ublox NEO-6. Since all >> the >>> beacons were originally designed based on 4800 baud NMEA, the Ublox was >> set >>> for this for backwards compatibility with the Garmin and the >> configuration >>> saved in NV ram. >>> >>> Now the query I have. I had assumed it was a 1024 week rollover that >>> killed the Garmin, but on testing teh module when I returned home, after >> a >>> longer than normal initialisation period it DID start outputting the >>> correct date and time, with PPS present. So the initial reboot failed, >>> even after a couple of days attempt, but after a power cycle it worked. >>> >>> I'm puzzled by that behaviour. Is anyone here familar with the GPS25 >>> family, dating from the turn of the millennium? >>> >>> As an aside, a Jupiter TU60 GPS module was also in use on site, >> delivering >>> a GPS locked 10kHz signal. This I used to lock a 10MHz reference in >>> "Probably the Simplest GPSDO Possible" http://g4jnt.com/SimpleGPSDO.pdf >>> That module, which is not a lot newer than the Garmin, did appear to have >>> survived the reboot as the resulting frequencies of the beacons were >>> spot-on when they returned with their modulation faults. However, in the >>> spirit of doing the job properly, it too is being replaced with a >>> Leo-Bodnar mini GPSDO. >>> All beacon details at scrbg.org >>> >>> >>> Andy >>> www.g4jnt.com >>> ___ >>> 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 tim
[time-nuts] Re: Garmin GPS 25 Module
I have a number of Garmin GPS35s which are the same engine in a mouse package. They are still working and do not have the roll-over problem because they can be programmed with the current date and time if need be (I wish Trimble had done this with the Thunderbolts). The NVRAM can get corrupted and may take a while to reset. I also have a procedure I got from Garmin to clear it if it does not take care of itself. David N1HAC On 2/9/22 10:57 AM, Andy Talbot wrote: Yes, I had to disable the GSV sentence to get the data flow down to a level that could be sent at the lower speed. I'm only using GPRMC, so all the others could be removed as well, but as GPRMC comes first in the block every second, there's nothing to be gained from killing any of the others sentences. I did fall foul once of a changed format. Originally I wrote for an RMC string that just gave integer seconds. On using my code with a later module it failed, and I spotted that it was sending decimal seconds, so had to rewrite my PIC code to cope with that. Then later, using other module types, GPRMC became GNRMC to cope with Glonass etc. so that was another change needed. Andy https://nam12.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.g4jnt.com%2F&data=04%7C01%7Cdavid.g.mcgaw%40dartmouth.edu%7C4d1fde6e4e5847e5ef7608d9ebe686f2%7C995b093648d640e5a31ebf689ec9446f%7C0%7C0%7C637800197633061750%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=EEF8lAjyACwHRvSDDZG0lyW6w%2BZPBJcJuqZeZ6Jrt8s%3D&reserved=0 On Wed, 9 Feb 2022 at 15:49, Bob kb8tq wrote: Hi In terms of upgrading the GPS module(s): You might want to look at just *what* NMEA messages are being used. While the format is “standard” it’s not quite dead nuts in some cases. Vendors get to add this and that and it still is NMEA. Converting from one family to another is not always easy. I would also want to check the GPS antenna at the remote site. They don’t last forever. Flakey sat signals can drive a module a bit nuts. GPS modules have gotten pretty cheap over the years. If this is a long drive / crazy access sort of thing, redundancy is not as expensive on the module (or antenna) side as it once was. Bob On Feb 9, 2022, at 4:36 AM, Andy Talbot wrote: I run a set of microwave beacons on a remote site that transmit data modes whose Tx timing is controlled from GPS. They were installed some 20 years ago and used a Garmin GPS25-LVS module to deliver NMA and 1 PPS signals to all five individual controllers. After a power outage that lasted a couple of days, the beacons fired up but it was clear, after a couple of days timing was corrupted. Each beacon has slightly different controller firmware, and by monitoring the resulting corrupted modulation it could be determined what was wrong.No PPS signal was present - which killed modulation on two of them. NMEA timing data was present but the time being reported was out by several seconds, rendering the data signal transmitted undecodable by most people. I went up to the remote site to recover the old hardware and am in the process of replacing the timing source using a Ublox NEO-6. Since all the beacons were originally designed based on 4800 baud NMEA, the Ublox was set for this for backwards compatibility with the Garmin and the configuration saved in NV ram. Now the query I have. I had assumed it was a 1024 week rollover that killed the Garmin, but on testing teh module when I returned home, after a longer than normal initialisation period it DID start outputting the correct date and time, with PPS present. So the initial reboot failed, even after a couple of days attempt, but after a power cycle it worked. I'm puzzled by that behaviour. Is anyone here familar with the GPS25 family, dating from the turn of the millennium? As an aside, a Jupiter TU60 GPS module was also in use on site, delivering a GPS locked 10kHz signal. This I used to lock a 10MHz reference in "Probably the Simplest GPSDO Possible" https://nam12.safelinks.protection.outlook.com/?url=http%3A%2F%2Fg4jnt.com%2FSimpleGPSDO.pdf&data=04%7C01%7Cdavid.g.mcgaw%40dartmouth.edu%7C4d1fde6e4e5847e5ef7608d9ebe686f2%7C995b093648d640e5a31ebf689ec9446f%7C0%7C0%7C637800197633061750%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=WhJg63l8ZeetkN4G%2FbvI6Nx9pi9M3cbFeHXXH%2F4oWQo%3D&reserved=0 That module, which is not a lot newer than the Garmin, did appear to have survived the reboot as the resulting frequencies of the beacons were spot-on when they returned with their modulation faults. However, in the spirit of doing the job properly, it too is being replaced with a Leo-Bodnar mini GPSDO. All beacon details at scrbg.org Andy https://nam12.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.g4jnt.com%2F&data=04%7C01%7Cdavid.g.mcgaw%40dartmouth.edu%7C4d1fde6e4e5847e5ef7608d9ebe686f2%7C995b093648d640e5a31ebf68
[time-nuts] Re: Garmin GPS 25 Module
Yes, I had to disable the GSV sentence to get the data flow down to a level that could be sent at the lower speed. I'm only using GPRMC, so all the others could be removed as well, but as GPRMC comes first in the block every second, there's nothing to be gained from killing any of the others sentences. I did fall foul once of a changed format. Originally I wrote for an RMC string that just gave integer seconds. On using my code with a later module it failed, and I spotted that it was sending decimal seconds, so had to rewrite my PIC code to cope with that. Then later, using other module types, GPRMC became GNRMC to cope with Glonass etc. so that was another change needed. Andy www.g4jnt.com On Wed, 9 Feb 2022 at 15:49, Bob kb8tq wrote: > Hi > > In terms of upgrading the GPS module(s): > > You might want to look at just *what* NMEA messages are being used. > While the format is “standard” it’s not quite dead nuts in some cases. > Vendors get to add this and that and it still is NMEA. Converting from > one family to another is not always easy. > > I would also want to check the GPS antenna at the remote site. They > don’t last forever. Flakey sat signals can drive a module a bit nuts. > > GPS modules have gotten pretty cheap over the years. If this is a long > drive / crazy access sort of thing, redundancy is not as expensive on > the module (or antenna) side as it once was. > > Bob > > > On Feb 9, 2022, at 4:36 AM, Andy Talbot wrote: > > > > I run a set of microwave beacons on a remote site that transmit data > modes > > whose Tx timing is controlled from GPS. They were installed some 20 > years > > ago and used a Garmin GPS25-LVS module to deliver NMA and 1 PPS signals > to > > all five individual controllers. > > > > After a power outage that lasted a couple of days, the beacons fired up > but > > it was clear, after a couple of days timing was corrupted. Each beacon > has > > slightly different controller firmware, and by monitoring the resulting > > corrupted modulation it could be determined what was wrong.No PPS > > signal was present - which killed modulation on two of them. NMEA timing > > data was present but the time being reported was out by several seconds, > > rendering the data signal transmitted undecodable by most people. > > > > I went up to the remote site to recover the old hardware and am in the > > process of replacing the timing source using a Ublox NEO-6. Since all > the > > beacons were originally designed based on 4800 baud NMEA, the Ublox was > set > > for this for backwards compatibility with the Garmin and the > configuration > > saved in NV ram. > > > > Now the query I have. I had assumed it was a 1024 week rollover that > > killed the Garmin, but on testing teh module when I returned home, after > a > > longer than normal initialisation period it DID start outputting the > > correct date and time, with PPS present. So the initial reboot failed, > > even after a couple of days attempt, but after a power cycle it worked. > > > > I'm puzzled by that behaviour. Is anyone here familar with the GPS25 > > family, dating from the turn of the millennium? > > > > As an aside, a Jupiter TU60 GPS module was also in use on site, > delivering > > a GPS locked 10kHz signal. This I used to lock a 10MHz reference in > > "Probably the Simplest GPSDO Possible" http://g4jnt.com/SimpleGPSDO.pdf > > That module, which is not a lot newer than the Garmin, did appear to have > > survived the reboot as the resulting frequencies of the beacons were > > spot-on when they returned with their modulation faults. However, in the > > spirit of doing the job properly, it too is being replaced with a > > Leo-Bodnar mini GPSDO. > > All beacon details at scrbg.org > > > > > > Andy > > www.g4jnt.com > > ___ > > 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: Garmin GPS 25 Module
Andy So funny. I had some of these old gps units. Like you they sort of died over time. I have to say taking the plastic top off was difficult. Never discovered what was up. But I did the same as you. The cheap and cheerful NEO-6. That was the end of any issue. Regards Paul WB8TSL On Wed, Feb 9, 2022 at 9:23 AM Andy Talbot wrote: > I run a set of microwave beacons on a remote site that transmit data modes > whose Tx timing is controlled from GPS. They were installed some 20 years > ago and used a Garmin GPS25-LVS module to deliver NMA and 1 PPS signals to > all five individual controllers. > > After a power outage that lasted a couple of days, the beacons fired up but > it was clear, after a couple of days timing was corrupted. Each beacon has > slightly different controller firmware, and by monitoring the resulting > corrupted modulation it could be determined what was wrong.No PPS > signal was present - which killed modulation on two of them. NMEA timing > data was present but the time being reported was out by several seconds, > rendering the data signal transmitted undecodable by most people. > > I went up to the remote site to recover the old hardware and am in the > process of replacing the timing source using a Ublox NEO-6. Since all the > beacons were originally designed based on 4800 baud NMEA, the Ublox was set > for this for backwards compatibility with the Garmin and the configuration > saved in NV ram. > > Now the query I have. I had assumed it was a 1024 week rollover that > killed the Garmin, but on testing teh module when I returned home, after a > longer than normal initialisation period it DID start outputting the > correct date and time, with PPS present. So the initial reboot failed, > even after a couple of days attempt, but after a power cycle it worked. > > I'm puzzled by that behaviour. Is anyone here familar with the GPS25 > family, dating from the turn of the millennium? > > As an aside, a Jupiter TU60 GPS module was also in use on site, delivering > a GPS locked 10kHz signal. This I used to lock a 10MHz reference in > "Probably the Simplest GPSDO Possible" http://g4jnt.com/SimpleGPSDO.pdf > That module, which is not a lot newer than the Garmin, did appear to have > survived the reboot as the resulting frequencies of the beacons were > spot-on when they returned with their modulation faults. However, in the > spirit of doing the job properly, it too is being replaced with a > Leo-Bodnar mini GPSDO. > All beacon details at scrbg.org > > > Andy > www.g4jnt.com > ___ > 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: Garmin GPS 25 Module
Hi In terms of upgrading the GPS module(s): You might want to look at just *what* NMEA messages are being used. While the format is “standard” it’s not quite dead nuts in some cases. Vendors get to add this and that and it still is NMEA. Converting from one family to another is not always easy. I would also want to check the GPS antenna at the remote site. They don’t last forever. Flakey sat signals can drive a module a bit nuts. GPS modules have gotten pretty cheap over the years. If this is a long drive / crazy access sort of thing, redundancy is not as expensive on the module (or antenna) side as it once was. Bob > On Feb 9, 2022, at 4:36 AM, Andy Talbot wrote: > > I run a set of microwave beacons on a remote site that transmit data modes > whose Tx timing is controlled from GPS. They were installed some 20 years > ago and used a Garmin GPS25-LVS module to deliver NMA and 1 PPS signals to > all five individual controllers. > > After a power outage that lasted a couple of days, the beacons fired up but > it was clear, after a couple of days timing was corrupted. Each beacon has > slightly different controller firmware, and by monitoring the resulting > corrupted modulation it could be determined what was wrong.No PPS > signal was present - which killed modulation on two of them. NMEA timing > data was present but the time being reported was out by several seconds, > rendering the data signal transmitted undecodable by most people. > > I went up to the remote site to recover the old hardware and am in the > process of replacing the timing source using a Ublox NEO-6. Since all the > beacons were originally designed based on 4800 baud NMEA, the Ublox was set > for this for backwards compatibility with the Garmin and the configuration > saved in NV ram. > > Now the query I have. I had assumed it was a 1024 week rollover that > killed the Garmin, but on testing teh module when I returned home, after a > longer than normal initialisation period it DID start outputting the > correct date and time, with PPS present. So the initial reboot failed, > even after a couple of days attempt, but after a power cycle it worked. > > I'm puzzled by that behaviour. Is anyone here familar with the GPS25 > family, dating from the turn of the millennium? > > As an aside, a Jupiter TU60 GPS module was also in use on site, delivering > a GPS locked 10kHz signal. This I used to lock a 10MHz reference in > "Probably the Simplest GPSDO Possible" http://g4jnt.com/SimpleGPSDO.pdf > That module, which is not a lot newer than the Garmin, did appear to have > survived the reboot as the resulting frequencies of the beacons were > spot-on when they returned with their modulation faults. However, in the > spirit of doing the job properly, it too is being replaced with a > Leo-Bodnar mini GPSDO. > All beacon details at scrbg.org > > > Andy > www.g4jnt.com > ___ > 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: HP Z3801A project update
Hi > On Feb 8, 2022, at 11:16 PM, ed breya wrote: > > Sorry I haven't been proactive on this. My main PC crapped out last week in a > big way. I've been doing almost a total rebuild on it. Just got internet and > email working this morning, followed by printer problems. > > Regarding the Z3801A date/rollover issue, it looks like there's no easy fix, > so I can let it go. As long as it makes the 10 MHz and 1 PPS properly, and I > can check what it's doing occasionally with SatStat, I think I'm good to go. > I can figure out the date and time in other ways too - sometimes, just > knowing AM or PM is good enough. As mentioned in an earlier post LH can fix the date for you. She can also do plots of just about anything you can think of. This can be very helpful for troubleshooting. > > Now, what about that EFC? Does its behavior that I reported earlier seem like > it's OK, considering the setup and reception? EFC does not mean a lot on these devices unless you hit a limit or something like that. > > I did try a survey, as suggested, and it indeed came up with slightly > different nav coordinates, and also took a whole day to do it - satellite > view is so poor with my temporary setup, it mostly saw only two or three, and > sometimes jumped all the way to four or five. These old receivers need all the help they can get in terms of antenna location. You very much do want a clear sky view and a full set (6 to 8) of sats in view and usable. Going below 4 sats “locked on” is not a good thing. Bob > > I hope this email gets through OK. More later. > > Ed > ___ > 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] Garmin GPS 25 Module
I run a set of microwave beacons on a remote site that transmit data modes whose Tx timing is controlled from GPS. They were installed some 20 years ago and used a Garmin GPS25-LVS module to deliver NMA and 1 PPS signals to all five individual controllers. After a power outage that lasted a couple of days, the beacons fired up but it was clear, after a couple of days timing was corrupted. Each beacon has slightly different controller firmware, and by monitoring the resulting corrupted modulation it could be determined what was wrong.No PPS signal was present - which killed modulation on two of them. NMEA timing data was present but the time being reported was out by several seconds, rendering the data signal transmitted undecodable by most people. I went up to the remote site to recover the old hardware and am in the process of replacing the timing source using a Ublox NEO-6. Since all the beacons were originally designed based on 4800 baud NMEA, the Ublox was set for this for backwards compatibility with the Garmin and the configuration saved in NV ram. Now the query I have. I had assumed it was a 1024 week rollover that killed the Garmin, but on testing teh module when I returned home, after a longer than normal initialisation period it DID start outputting the correct date and time, with PPS present. So the initial reboot failed, even after a couple of days attempt, but after a power cycle it worked. I'm puzzled by that behaviour. Is anyone here familar with the GPS25 family, dating from the turn of the millennium? As an aside, a Jupiter TU60 GPS module was also in use on site, delivering a GPS locked 10kHz signal. This I used to lock a 10MHz reference in "Probably the Simplest GPSDO Possible" http://g4jnt.com/SimpleGPSDO.pdf That module, which is not a lot newer than the Garmin, did appear to have survived the reboot as the resulting frequencies of the beacons were spot-on when they returned with their modulation faults. However, in the spirit of doing the job properly, it too is being replaced with a Leo-Bodnar mini GPSDO. All beacon details at scrbg.org Andy www.g4jnt.com ___ 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.
