Re: [time-nuts] The Symmetricom GPS Antenna's (Export licenses? are there any needed?)
Does anyone know of any issue with licensing (export licenses) for these? I seldom hesitate to ship old computer stuff I have, but that GPS is technically a military tool gives me pause to step up. The vendor may have such things ironed out, but individuals that step up here may have a hassle to worse to send them to you guys in Europe. Not sure of restrictions, maybe someone can comment. Maybe a bulk buy thru someone who can transship to the appropriate place in Europe then send out most economically from there would work. But high shipping rates is par for what I've had to pay to send computer things one at a time to Europe. I had a discussion just last week about shipping out a lot of test equipment and RF stuff that the naive user might get into a world of hurt shipping. (not Time Nut type but restricted). There was not a lot to indicate what was going to get you into trouble. Typical problems were "just sell it to me and ship it to this export broker @ xyz NYC or such) which of course doesn't relieve the seller of responsibility of export licensing, etc. This was done on several Ebay sales just to clarify the problem and ways people overseas were trying to get people to do the wrong thing. thanks Jim On 10/2/2015 10:36 AM, Roy Phillips wrote: For we Europeans, British in my case, the Symmetricom GPS antennas are very good buy – but the addition of US $60.00 for the shipping makes them rather expensive ! – plus taxes .. Roy ___ 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] KS-24361 REF-0 standalone
Hi If indeed you are into a professional system, where holdover matters then a lashup on a bunch of surplus gear likely isn’t going to measure up. Based on about 10,000 previous posts on the list I’d say that holdover does not appear to matter to Time Nuts. It would be difficult to find a thread where holdover performance was the main topic. The focus (rightly) seems to be to keep the box locked to GPS all the time. That approach (if you can do it) will always give you the best timing. The “not a T” uBlox units *do* put out “TRAIM" information in the words you can get at. The data is valid and it can be used if you wish to put the unit in holdover. I’m sure it works better with a well known position, but that it not a requisite. TRAIM was a really big deal back in the mid 90’s. That’s when Motorola put it on the Oncore’s and did a lot of publicity on the topic. They saw it as a way to differentiate their product in the marketplace. Much of our view of TRAIM is slanted by the Motorola information on the topic. Here’s one way to look at TRAIM: If you are in position hold, you can get timing off of a single satellite. TRAIM (just like any estimator) looks at the single input it has and says “that must be correct”. Give it two inputs and it can look at the solution for each and decide if they are close enough (your TRAIM threshold) to be correct. As you get up to 8 or 12 inputs, the right answer may be to throw away the single one that is (say) a microsecond off from the rest. Somewhere between 3 satellites and 6 satellites, the “I need a solid position” thing becomes less of a factor. There are other ways to put the device into holdover. One is to simply look at the number of satellites. If you are locked on to less than 4 sats, go into holdover. It’s not elegant, but it does work. In the case of a lash up, just translate the “I have <= 3 sats” info into “my TRAIM is junk”. Instant holdover. Bob > On Oct 2, 2015, at 10:44 PM, Bill Hawkinswrote: > > Actually, the Lucent software uses RAIM, and reports the value in its > status message. If the position appears to have drifted off, or there > aren't enough satellites to calculate the position, the software > declares the oscillators to be free-wheeling, an expression meaning that > the oscillators are free from discipline and are now drifting. > > So yes, the positioning aspects matter. > > Disclaimer: I haven't studied RAIM (or TRAIM) enough to know exactly > what goes on, but that's the behavior I've observed. > > Bill Hawkins > > > -Original Message- > From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Gregory > Beat > Sent: Friday, October 02, 2015 6:07 PM > To: time-nuts@febo.com > Subject: Re: [time-nuts] KS-24361 REF-0 standalone > > Dan - > > I have been following your experimentation with the surplus Lucent > KS-24361 REF-0 module, to transform it into a standalone GPSDO. > > The original usage of the classic Oncore UT+ GPS receiver for KS-24361 > REF-1, by Symmetricom / Datum for Lucent, was deliberate. > For usage at a cellular data/telecom site, the focus was on the timing > and frequency discipline from the GPS satellite transmission, rather > than the position or dead reckoning aspects -- used by smartphones, > automobiles, and other GPS applications on the market. > === > A couple of comments. > While I can appreciate being economical (main criteria) and selecting > the NEO-6M receiver, I believe that a u-Blox timing specific module > (like LEA-6T) would be more desirable in this application. > > In addition, the u-Blox 6-series is the trailing edge of product support > (market demand dictates its continuance), while the 7 and 8-series are > their current modules (largely for the cellular / mobile industry > (smartphones or cell sites themselves) > > u-Blox 6-series Timing Application Note (using the LEA-6T) > https://www.u-blox.com/sites/default/files/products/documents/Timing_App > Note_%28GPS.G6-X-11007%29.pdf > > IF you successfully adopt the u-Blox module to correctly "mimic" the > Oncore UT+ GPS receiver command suite, THEN you open up a larger > audience of "time-nuts" and Frequency Standard users (HP Z3801A > frequency standard universe) as a receiver alternative. > http://www.realhamradio.com/GPS_Frequency_Standard.htm > > These users may desire a "newer" GPS receiver that has more channels > (8-channel); latest generation receiver; access to the newest GPS > constellations. > TAPR might be interested in sponsoring, as a kit/module, if a wider > audience existed. > > The Heol Designs N024 receiver (France) accomplished this replacement > role for the Trimble ACE II/III GPS receiver used in the > Symmetricom/Datum TymServe TS2100. > Their solution resolved shortcomings in the mid-1990 Trimble receiver > design and giving this Symmetricom NTP server, time IRIG-B time code > generator, and 10 MHz reference appliance a new lease on life (no longer >
Re: [time-nuts] The Symmetricom GPS Antenna's (Export licenses? are there any needed?)
Hi These antennas are in the same league as a automotive GPS. Since they don’t even have the GPS receiver in them, they actually have fewer regulations on them. As such there are no restrictions on exporting them. That said, I don’t think I would ship anything (even a bottle of milk) to some countries without expecting a hassle. As long as you are shipping to Europe, there should be no problem at all. Bob > On Oct 3, 2015, at 4:05 AM, jim swrote: > > Does anyone know of any issue with licensing (export licenses) for these? I > seldom hesitate to ship old computer stuff I have, but that GPS is > technically a military tool gives me pause to step up. The vendor may have > such things ironed out, but individuals that step up here may have a hassle > to worse to send them to you guys in Europe. > > Not sure of restrictions, maybe someone can comment. > > Maybe a bulk buy thru someone who can transship to the appropriate place in > Europe then send out most economically from there would work. But high > shipping rates is par for what I've had to pay to send computer things one at > a time to Europe. > > I had a discussion just last week about shipping out a lot of test equipment > and RF stuff that the naive user might get into a world of hurt shipping. > (not Time Nut type but restricted). There was not a lot to indicate what was > going to get you into trouble. > > Typical problems were "just sell it to me and ship it to this export broker @ > xyz NYC or such) which of course doesn't relieve the seller of responsibility > of export licensing, etc. This was done on several Ebay sales just to > clarify the problem and ways people overseas were trying to get people to do > the wrong thing. > > thanks > Jim > > On 10/2/2015 10:36 AM, Roy Phillips wrote: >> For we Europeans, British in my case, the Symmetricom GPS antennas are very >> good buy – but the addition of US $60.00 for the shipping makes them rather >> expensive ! – plus taxes .. >> Roy >> >> ___ >> 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] KS-24361 REF-0 standalone
Hi There are a number of papers out there (check the NIST archive) on GPS vs Gloanss timing. The simple answer at this point is “don’t bother”. Bob > On Oct 3, 2015, at 1:28 AM, Hal Murraywrote: > > > kb...@n1k.org said: >> The main thing you get with the 7’s (vs the 5 and 6) is the ability to >> switch over to Glonass. With the 8’s you get the ability to run Glonass plus >> GPS at the same time. In both cases, you get nothing from the Glonass >> constellation that’s worth the switch. In a timing application you likely >> would run “pure GPS”. > > Has anybody compared timing from Glonass to timing from GPS and/or timing > from both? > > > > -- > 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.
[time-nuts] Symmetricom sa.31m serial protocol
Hi. Sorry for messing up the last post. I try again: Does anyone have the specification of the serial port protocol for the Symmetricom / Microsemi sa.31m ? I could only download the datasheet which does not give any information on the syntax or the available commands. Thanks in advance, Bernd Plannerer ___ 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] Looking for ECL divide by 3 with symmetry
After studying the various divide by 3 circuits, I decided to try designing one that would be simpler in terms of package count, using available ECL DIPs on-hand. Instead of the JK-FF version followed by duty cycle-fixing circuitry, I opted for two 10131 dual D-FFs to provide the state machine, with 50 percent duty cycle. A 10116 line receiver provides the input interface and two-phase clock. So, a circuit of three DIP packages does the whole works. A quick paper analysis showed that it should work. I gathered up the parts and I built it onto a small vector circuit board, but it did not work. I did it relatively quickly, so probably have a wiring error to figure out. To make sure I didn't miss something, I ran a check with a simple logic simulator that I found, and it proved out OK, design-wise, so I think it should be good to go once I figure out the proper wiring. A summary of the circuit and operational simulation is attached. It should be fully synchronous and glitchless up to the toggle limit. Also, starting it from the one disallowed state seems to be no problem - it quickly cycles to the proper sequence. Using D-FF decoding within the counter section has a little more prop delay than the gated versions. I didn't check the timing limitations yet, but I'm pretty sure it will be OK at the required 50 MHz toggle rate. Ed div3 sim1.rtf Description: MS-Word document ___ 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] KS-24361 REF-0 standalone
Dan it looks like the thread has re-developed. As my early test of your simple solution demonstrated. Better PPS better stability (Used a TBolt to test this) in the form of semi-short term jitter. The beauty of Dans solution is the user can select the quality and cost of the receiver used. Anything can work. I used the 6M also because of the $11 cost and at the time as a alpha tester there could have been issues. Reality, the 6M was on the shelf. Regards Paul WB8TSL On Sat, Oct 3, 2015 at 9:47 AM, Bob Campwrote: > Hi > > If indeed you are into a professional system, where holdover matters then > a lashup on a bunch of surplus gear likely isn’t going to measure up. Based > on about 10,000 previous posts on the list I’d say that holdover does not > appear > to matter to Time Nuts. It would be difficult to find a thread where > holdover performance > was the main topic. The focus (rightly) seems to be to keep the box locked > to > GPS all the time. That approach (if you can do it) will always give you > the best > timing. > > The “not a T” uBlox units *do* put out “TRAIM" information in the words you > can get at. The data is valid and it can be used if you wish to put the > unit > in holdover. I’m sure it works better with a well known position, but that > it not > a requisite. > > TRAIM was a really big deal back in the mid 90’s. That’s when Motorola put > it on > the Oncore’s and did a lot of publicity on the topic. They saw it as a way > to differentiate > their product in the marketplace. Much of our view of TRAIM is slanted by > the > Motorola information on the topic. > > Here’s one way to look at TRAIM: > > If you are in position hold, you can get timing off of a single satellite. > TRAIM > (just like any estimator) looks at the single input it has and says “that > must be > correct”. Give it two inputs and it can look at the solution for each and > decide if > they are close enough (your TRAIM threshold) to be correct. As you get up > to 8 or > 12 inputs, the right answer may be to throw away the single one that is > (say) a microsecond > off from the rest. Somewhere between 3 satellites and 6 satellites, the “I > need > a solid position” thing becomes less of a factor. > > There are other ways to put the device into holdover. One is to simply > look at the > number of satellites. If you are locked on to less than 4 sats, go into > holdover. It’s not > elegant, but it does work. In the case of a lash up, just translate the “I > have <= 3 sats” info into > “my TRAIM is junk”. Instant holdover. > > Bob > > > > On Oct 2, 2015, at 10:44 PM, Bill Hawkins wrote: > > > > Actually, the Lucent software uses RAIM, and reports the value in its > > status message. If the position appears to have drifted off, or there > > aren't enough satellites to calculate the position, the software > > declares the oscillators to be free-wheeling, an expression meaning that > > the oscillators are free from discipline and are now drifting. > > > > So yes, the positioning aspects matter. > > > > Disclaimer: I haven't studied RAIM (or TRAIM) enough to know exactly > > what goes on, but that's the behavior I've observed. > > > > Bill Hawkins > > > > > > -Original Message- > > From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Gregory > > Beat > > Sent: Friday, October 02, 2015 6:07 PM > > To: time-nuts@febo.com > > Subject: Re: [time-nuts] KS-24361 REF-0 standalone > > > > Dan - > > > > I have been following your experimentation with the surplus Lucent > > KS-24361 REF-0 module, to transform it into a standalone GPSDO. > > > > The original usage of the classic Oncore UT+ GPS receiver for KS-24361 > > REF-1, by Symmetricom / Datum for Lucent, was deliberate. > > For usage at a cellular data/telecom site, the focus was on the timing > > and frequency discipline from the GPS satellite transmission, rather > > than the position or dead reckoning aspects -- used by smartphones, > > automobiles, and other GPS applications on the market. > > === > > A couple of comments. > > While I can appreciate being economical (main criteria) and selecting > > the NEO-6M receiver, I believe that a u-Blox timing specific module > > (like LEA-6T) would be more desirable in this application. > > > > In addition, the u-Blox 6-series is the trailing edge of product support > > (market demand dictates its continuance), while the 7 and 8-series are > > their current modules (largely for the cellular / mobile industry > > (smartphones or cell sites themselves) > > > > u-Blox 6-series Timing Application Note (using the LEA-6T) > > https://www.u-blox.com/sites/default/files/products/documents/Timing_App > > Note_%28GPS.G6-X-11007%29.pdf > > > > IF you successfully adopt the u-Blox module to correctly "mimic" the > > Oncore UT+ GPS receiver command suite, THEN you open up a larger > > audience of "time-nuts" and Frequency Standard users (HP Z3801A > > frequency standard universe) as a receiver
[time-nuts] Symmetricom sa.31m serial port protocol description
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Re: [time-nuts] KS-24361 REF-0 standalone
kb...@n1k.org said: > The main thing you get with the 7âs (vs the 5 and 6) is the ability to > switch over to Glonass. With the 8âs you get the ability to run Glonass plus > GPS at the same time. In both cases, you get nothing from the Glonass > constellation thatâs worth the switch. In a timing application you likely > would run âpure GPSâ. Has anybody compared timing from Glonass to timing from GPS and/or timing from both? -- 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] Symmetricom TM7000 TymMachine
Hi, would anyone here have a user manual for the TM7000 unit as a pdf? Or the configuration software for the RS232 port? Thanks Linden ___ 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.