[time-nuts] Trimble Nortel GPSTM Boards
In Lady Hather, set the elevation mask to a low value, clear the signal level data (S A C), let the unit run for a day or so, then do the oscillator autotune (A). This will set the elevation mask to a level that matches what your antenna can see. Or you can check the elevation plot (S A E) and see where the tick mark shows the signal level dropping off and enter that value manually. ___ 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 Nortel GPSTM Boards
Hi Jim, Yes I did, no value was perfect in this respect, ie as affecting the DAC steps, so settled on 20 as a bit of a compromise. The number of sats being tracked still seems to be a factor in the equation, setting an elevation angle of 20 degrees had quite a smoothing effect last night, today I'm back to much more noticeable steps again. Although I have used Lady Heather in the past I've tended rather to stick with Trimbles own more simplistic software for making basic adjustments and just to ensure things are set up and working ok, so I'm back on a fairly steep learning curve and perhaps being given too much information for my own good:-) Regards Nigel GM8PZR In a message dated 06/08/2013 01:15:17 GMT Daylight Time, wb4...@wb4gcs.org writes: Did you /increase/ the elevation mask? Jim wb4...@amsat.org On 8/5/2013 8:06 PM, gandal...@aol.com wrote: Many thanks to those who commented on this and apologies for the delayed response, having spent a few days in an internet free zone I've also had to contend with a couple of power failures since returning but am just about getting back to normal again, whatever normal might be:-) As suggested, changing the elevation mask does make a difference to the DAC voltage jumps, I'd just run up Lady Heather on default settings to start with which sets it to 10 degrees and changing that to 20 degrees, for example, has reduced the steps in the DAC voltage as sats come and go, they're still there but not so pronounced. Having said that, comparing this with a Thunderbolt, albeit using another Thunderbolt as the reference for both, does tend to give more pronounced steps on the Thunderbolt for the same elevation mask and sensitivity settings. As others have commented previously I'm also noticing the much reduced temperature sensitivity of this unit compared with the Thunderbolt which is quite a big plus, but it's not all totally one sided, both Lady Heather and a couple of Pendulum counters are showing somewhat lower Adev values for the Thunderbolt although the plots of frequency against time show very similar limits. Either way, so far at least this does seem to be working well. I still haven't heard from anyone who's run the two available GPSTM variants side by side so I'm still debating whether or not to try that for myself, or whether to just quit whilst I'm ahead:-) Regards Nigel GM8PZR In a message dated 31/07/2013 22:48:13 GMT Daylight Time, gandal...@aol.com writes: Having stuck a late bid on a recent auction for what I'd assumed was a Trimble Nortel NTGS50AA I then realised I'd just bought the single board version, part number 4500-00-CH with the Trimble 49422-CR OCXO. That in itself wasn't a problem, except perhaps the doubts cast over my sanity:-), it arrived earlier today and has been running for several hours now, chatting comfortably with Lady Heather, and generally settling in nicely. However, it does prompt the question, has anyone had a chance to compare one of these side by side with an NTGS50AA and, if so, were there any obvious differences in performance? Regards Nigel GM8PZR ___ 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. ___ 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 Nortel GPSTM Boards
Hi Bjorn, Many thanks for the tip, I'd seen discussions on the two part boards, NTGS50AA, but hadn't realised the extent to which this version had also been mentioned. Given that it was discussed as recently as early July, including comments on the wheel I've just reinvented, and that I did read those comments at the time, I think it's perhaps time I took a break, or wrote out 500 times...I must pay more attention :-) Regards Nigel GM8PZR In a message dated 01/08/2013 20:21:00 GMT Daylight Time, b...@lysator.liu.se writes: Hi Nigel! This has been discussed before in time-nuts. I have two of the big boards, but they are not running right now. If I remember correctly the big ones are more of a cost reduction model compared to the 2 board split solition. Giving lower SV snr than the split version. But my ran just fine compared to my standard Tbolts. -- Björn Skickat från min Mobil Originalmeddelande Från: gandal...@aol.com Datum: 2013-08-01 11:09 (GMT+01:00) Till: time-nuts@febo.com Rubrik: Re: [time-nuts] Trimble Nortel GPSTM Boards Hi Charles Thanks for your comments, the surveyed position on this is looking pretty good but what I have now realised is that the severity of the jumps seems very much related to the number of sattelites being tracked. Switching from 8 to 7, or 7 to 8, sats seems to produce the biggest step change whilst switching in either direction between 5 and 6, for example, doesn't seem to show up at all on the monitored DAC voltage. Ok, I take that back, it does still seem to depend on the number of sats being switched between but I've just seen a switch from 5 to 4 sats induce a very noticeable step change in DAC voltage, so the relationship doesn't appear to be linear. Unfortunately I need to power this down now for a few days but will investigate more later. Regards Nigel GM8PZR In a message dated 01/08/2013 09:45:24 GMT Daylight Time, charles_steinm...@lavabit.com writes: Nigel wrote: at times I'm seeing very noticeable step changes in the DAC voltage on this one as that happens. ** * I am a bit surprised by the extent, a Mark Sims online plot from 2012 shows some correlation on an NTGS50AA but not as noticeable as this, and I don't recall seeing anything quite so pronounced on a Thunderbolt. IME (with TBolts), the magnitude of the DAC steps with constellation changes varies with the accuracy of the positional data used by the GPS. To a point, the more accurate the survey, the smaller the DAC jumps will be. (Other errors prevent reducing the constellation-change DAC steps to zero.) Mark has commented here on survey accuracy, and the methods he used in Lady Heather to maximize it. Best regards, Charles ___ 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. ___ 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 Nortel GPSTM Boards
Thanks Mark I'll start over and will do as you suggest. I'm sure you'll have been told this many times before but Lady Heather is an amazing piece of software, thank you, even if I do feel at times that I'm suffering from severe information overload:-) I guess this might be more a question for John Miles, to whom also many thanks for the Windows version, but I've noticed that, here at least, LH seems much happier running under XP than it does under Windows 7, unless of course it's a hardware issue. On a 3GHz P4, using a native serial port under XP, I'm seeing around 10% CPU load with time and data updating smoothly, whilst on a 2GHz dual core laptop using a serial to USB adapter under Win7 although it runs ok the CPU load is showing as around 50% and updates are erratic. It will tick away nicely for several seconds, then pause before making a dash to catch up, which it never quite manages with the display always at least a few seconds behind the XP machine. It's not a major problem, I can run more serial ports on the XP machine anyway, and I've not yet spent any time investigating further but it is just heather.exe that's showing as loading the CPU, so thought I'd ask first. Regards Nigel GM8PZR In a message dated 06/08/2013 08:10:49 GMT Daylight Time, hol...@hotmail.com writes: In Lady Hather, set the elevation mask to a low value, clear the signal level data (S A C), let the unit run for a day or so, then do the oscillator autotune (A). This will set the elevation mask to a level that matches what your antenna can see. Or you can check the elevation plot (S A E) and see where the tick mark shows the signal level dropping off and enter that value manually. ___ 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 Nortel GPSTM Boards
Many thanks to those who commented on this and apologies for the delayed response, having spent a few days in an internet free zone I've also had to contend with a couple of power failures since returning but am just about getting back to normal again, whatever normal might be:-) As suggested, changing the elevation mask does make a difference to the DAC voltage jumps, I'd just run up Lady Heather on default settings to start with which sets it to 10 degrees and changing that to 20 degrees, for example, has reduced the steps in the DAC voltage as sats come and go, they're still there but not so pronounced. Having said that, comparing this with a Thunderbolt, albeit using another Thunderbolt as the reference for both, does tend to give more pronounced steps on the Thunderbolt for the same elevation mask and sensitivity settings. As others have commented previously I'm also noticing the much reduced temperature sensitivity of this unit compared with the Thunderbolt which is quite a big plus, but it's not all totally one sided, both Lady Heather and a couple of Pendulum counters are showing somewhat lower Adev values for the Thunderbolt although the plots of frequency against time show very similar limits. Either way, so far at least this does seem to be working well. I still haven't heard from anyone who's run the two available GPSTM variants side by side so I'm still debating whether or not to try that for myself, or whether to just quit whilst I'm ahead:-) Regards Nigel GM8PZR In a message dated 31/07/2013 22:48:13 GMT Daylight Time, gandal...@aol.com writes: Having stuck a late bid on a recent auction for what I'd assumed was a Trimble Nortel NTGS50AA I then realised I'd just bought the single board version, part number 4500-00-CH with the Trimble 49422-CR OCXO. That in itself wasn't a problem, except perhaps the doubts cast over my sanity:-), it arrived earlier today and has been running for several hours now, chatting comfortably with Lady Heather, and generally settling in nicely. However, it does prompt the question, has anyone had a chance to compare one of these side by side with an NTGS50AA and, if so, were there any obvious differences in performance? Regards Nigel GM8PZR ___ 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 Nortel GPSTM Boards
Did you /increase/ the elevation mask? Jim wb4...@amsat.org On 8/5/2013 8:06 PM, gandal...@aol.com wrote: Many thanks to those who commented on this and apologies for the delayed response, having spent a few days in an internet free zone I've also had to contend with a couple of power failures since returning but am just about getting back to normal again, whatever normal might be:-) As suggested, changing the elevation mask does make a difference to the DAC voltage jumps, I'd just run up Lady Heather on default settings to start with which sets it to 10 degrees and changing that to 20 degrees, for example, has reduced the steps in the DAC voltage as sats come and go, they're still there but not so pronounced. Having said that, comparing this with a Thunderbolt, albeit using another Thunderbolt as the reference for both, does tend to give more pronounced steps on the Thunderbolt for the same elevation mask and sensitivity settings. As others have commented previously I'm also noticing the much reduced temperature sensitivity of this unit compared with the Thunderbolt which is quite a big plus, but it's not all totally one sided, both Lady Heather and a couple of Pendulum counters are showing somewhat lower Adev values for the Thunderbolt although the plots of frequency against time show very similar limits. Either way, so far at least this does seem to be working well. I still haven't heard from anyone who's run the two available GPSTM variants side by side so I'm still debating whether or not to try that for myself, or whether to just quit whilst I'm ahead:-) Regards Nigel GM8PZR In a message dated 31/07/2013 22:48:13 GMT Daylight Time, gandal...@aol.com writes: Having stuck a late bid on a recent auction for what I'd assumed was a Trimble Nortel NTGS50AA I then realised I'd just bought the single board version, part number 4500-00-CH with the Trimble 49422-CR OCXO. That in itself wasn't a problem, except perhaps the doubts cast over my sanity:-), it arrived earlier today and has been running for several hours now, chatting comfortably with Lady Heather, and generally settling in nicely. However, it does prompt the question, has anyone had a chance to compare one of these side by side with an NTGS50AA and, if so, were there any obvious differences in performance? Regards Nigel GM8PZR ___ 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 Nortel GPSTM Boards
Hi Either a blown receiver (likely the SAW filter) or antenna multi path. Bob On Aug 1, 2013, at 8:45 PM, Jim Sanford wb4...@wb4gcs.org wrote: I am seeing the same thing -- big jumps every single time a satellite is counted or not. Elevation mask 10 degrees, which should be very good and stable for my location. The unit also insists on converging to a bat altitude, then after a while declares stored position bad . .. then declares position good, even with bad altitude. Ideas appreciated. jimwb4...@amsat.org On 8/1/2013 6:31 AM, Bob Camp wrote: Hi You may have your elevation mask set to low for your antenna or a multi path issue from some other source. If the survey location is good to under a meter and the signals are good, there should be very little shift as sats are picked up or dropped. Bob On Aug 1, 2013, at 5:09 AM, gandal...@aol.com wrote: Hi Charles Thanks for your comments, the surveyed position on this is looking pretty good but what I have now realised is that the severity of the jumps seems very much related to the number of sattelites being tracked. Switching from 8 to 7, or 7 to 8, sats seems to produce the biggest step change whilst switching in either direction between 5 and 6, for example, doesn't seem to show up at all on the monitored DAC voltage. Ok, I take that back, it does still seem to depend on the number of sats being switched between but I've just seen a switch from 5 to 4 sats induce a very noticeable step change in DAC voltage, so the relationship doesn't appear to be linear. Unfortunately I need to power this down now for a few days but will investigate more later. Regards Nigel GM8PZR In a message dated 01/08/2013 09:45:24 GMT Daylight Time, charles_steinm...@lavabit.com writes: Nigel wrote: at times I'm seeing very noticeable step changes in the DAC voltage on this one as that happens. * * * I am a bit surprised by the extent, a Mark Sims online plot from 2012 shows some correlation on an NTGS50AA but not as noticeable as this, and I don't recall seeing anything quite so pronounced on a Thunderbolt. IME (with TBolts), the magnitude of the DAC steps with constellation changes varies with the accuracy of the positional data used by the GPS. To a point, the more accurate the survey, the smaller the DAC jumps will be. (Other errors prevent reducing the constellation-change DAC steps to zero.) Mark has commented here on survey accuracy, and the methods he used in Lady Heather to maximize it. Best regards, Charles ___ 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. ___ 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 Nortel GPSTM Boards
Bob: Well, this is discouraging. The receiver seems to work -- receives the sats it should. Seriously doubt there's any multipath out here in the boondocks. Maybe some tree absorption at very low elevation, but very little in the way of reflectors. I'm on 10 acres on a hillside, with trees in the distance. Jim On 8/2/2013 9:24 AM, Bob Camp wrote: Hi Either a blown receiver (likely the SAW filter) or antenna multi path. Bob On Aug 1, 2013, at 8:45 PM, Jim Sanford wb4...@wb4gcs.org wrote: I am seeing the same thing -- big jumps every single time a satellite is counted or not. Elevation mask 10 degrees, which should be very good and stable for my location. The unit also insists on converging to a bat altitude, then after a while declares stored position bad . .. then declares position good, even with bad altitude. Ideas appreciated. jimwb4...@amsat.org On 8/1/2013 6:31 AM, Bob Camp wrote: Hi You may have your elevation mask set to low for your antenna or a multi path issue from some other source. If the survey location is good to under a meter and the signals are good, there should be very little shift as sats are picked up or dropped. Bob On Aug 1, 2013, at 5:09 AM, gandal...@aol.com wrote: Hi Charles Thanks for your comments, the surveyed position on this is looking pretty good but what I have now realised is that the severity of the jumps seems very much related to the number of sattelites being tracked. Switching from 8 to 7, or 7 to 8, sats seems to produce the biggest step change whilst switching in either direction between 5 and 6, for example, doesn't seem to show up at all on the monitored DAC voltage. Ok, I take that back, it does still seem to depend on the number of sats being switched between but I've just seen a switch from 5 to 4 sats induce a very noticeable step change in DAC voltage, so the relationship doesn't appear to be linear. Unfortunately I need to power this down now for a few days but will investigate more later. Regards Nigel GM8PZR In a message dated 01/08/2013 09:45:24 GMT Daylight Time, charles_steinm...@lavabit.com writes: Nigel wrote: at times I'm seeing very noticeable step changes in the DAC voltage on this one as that happens. * * * I am a bit surprised by the extent, a Mark Sims online plot from 2012 shows some correlation on an NTGS50AA but not as noticeable as this, and I don't recall seeing anything quite so pronounced on a Thunderbolt. IME (with TBolts), the magnitude of the DAC steps with constellation changes varies with the accuracy of the positional data used by the GPS. To a point, the more accurate the survey, the smaller the DAC jumps will be. (Other errors prevent reducing the constellation-change DAC steps to zero.) Mark has commented here on survey accuracy, and the methods he used in Lady Heather to maximize it. Best regards, Charles ___ 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. ___ 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 Nortel GPSTM Boards
Hi Bob It's certainly very much from the same family, these seem to be a couple of years more recent but obviously aimed at the same spec, and I don't doubt they're going to behave in basically the same way, but given that such things are firmware driven that doesn't exclude possible quirks. By way of example, I'm running this on an indoor antenna right now, not bad but satellites do drop in and out, and at times I'm seeing very noticeable step changes in the DAC voltage on this one as that happens. Warren S has commented on this with the Thunderbolt so it's no great surprise but I am a bit surprised by the extent, a Mark Sims online plot from 2012 shows some correlation on an NTGS50AA but not as noticeable as this, and I don't recall seeing anything quite so pronounced on a Thunderbolt. Similarly, other than scaling, the DAC voltage on PPS plots are just about identical. Again not a problem, but I was just curious to see if anyone had compared the two side by side. Regards Nigel GM8PZR In a message dated 31/07/2013 22:59:31 GMT Daylight Time, li...@rtty.us writes: Hi From looking at a picture of one, it seems to have all the same stuff on it as the NTGS50 era gizmos. It should behave the same way. Bob On Jul 31, 2013, at 5:42 PM, gandal...@aol.com wrote: Having stuck a late bid on a recent auction for what I'd assumed was a Trimble Nortel NTGS50AA I then realised I'd just bought the single board version, part number 4500-00-CH with the Trimble 49422-CR OCXO. That in itself wasn't a problem, except perhaps the doubts cast over my sanity:-), it arrived earlier today and has been running for several hours now, chatting comfortably with Lady Heather, and generally settling in nicely. However, it does prompt the question, has anyone had a chance to compare one of these side by side with an NTGS50AA and, if so, were there any obvious differences in performance? Regards Nigel GM8PZR ___ 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 ht tps://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 Nortel GPSTM Boards
Hi Charles Thanks for your comments, the surveyed position on this is looking pretty good but what I have now realised is that the severity of the jumps seems very much related to the number of sattelites being tracked. Switching from 8 to 7, or 7 to 8, sats seems to produce the biggest step change whilst switching in either direction between 5 and 6, for example, doesn't seem to show up at all on the monitored DAC voltage. Ok, I take that back, it does still seem to depend on the number of sats being switched between but I've just seen a switch from 5 to 4 sats induce a very noticeable step change in DAC voltage, so the relationship doesn't appear to be linear. Unfortunately I need to power this down now for a few days but will investigate more later. Regards Nigel GM8PZR In a message dated 01/08/2013 09:45:24 GMT Daylight Time, charles_steinm...@lavabit.com writes: Nigel wrote: at times I'm seeing very noticeable step changes in the DAC voltage on this one as that happens. * * * I am a bit surprised by the extent, a Mark Sims online plot from 2012 shows some correlation on an NTGS50AA but not as noticeable as this, and I don't recall seeing anything quite so pronounced on a Thunderbolt. IME (with TBolts), the magnitude of the DAC steps with constellation changes varies with the accuracy of the positional data used by the GPS. To a point, the more accurate the survey, the smaller the DAC jumps will be. (Other errors prevent reducing the constellation-change DAC steps to zero.) Mark has commented here on survey accuracy, and the methods he used in Lady Heather to maximize it. Best regards, Charles ___ 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 Nortel GPSTM Boards
Hi You may have your elevation mask set to low for your antenna or a multi path issue from some other source. If the survey location is good to under a meter and the signals are good, there should be very little shift as sats are picked up or dropped. Bob On Aug 1, 2013, at 5:09 AM, gandal...@aol.com wrote: Hi Charles Thanks for your comments, the surveyed position on this is looking pretty good but what I have now realised is that the severity of the jumps seems very much related to the number of sattelites being tracked. Switching from 8 to 7, or 7 to 8, sats seems to produce the biggest step change whilst switching in either direction between 5 and 6, for example, doesn't seem to show up at all on the monitored DAC voltage. Ok, I take that back, it does still seem to depend on the number of sats being switched between but I've just seen a switch from 5 to 4 sats induce a very noticeable step change in DAC voltage, so the relationship doesn't appear to be linear. Unfortunately I need to power this down now for a few days but will investigate more later. Regards Nigel GM8PZR In a message dated 01/08/2013 09:45:24 GMT Daylight Time, charles_steinm...@lavabit.com writes: Nigel wrote: at times I'm seeing very noticeable step changes in the DAC voltage on this one as that happens. * * * I am a bit surprised by the extent, a Mark Sims online plot from 2012 shows some correlation on an NTGS50AA but not as noticeable as this, and I don't recall seeing anything quite so pronounced on a Thunderbolt. IME (with TBolts), the magnitude of the DAC steps with constellation changes varies with the accuracy of the positional data used by the GPS. To a point, the more accurate the survey, the smaller the DAC jumps will be. (Other errors prevent reducing the constellation-change DAC steps to zero.) Mark has commented here on survey accuracy, and the methods he used in Lady Heather to maximize it. Best regards, Charles ___ 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 Nortel GPSTM Boards
Hi Nigel! This has been discussed before in time-nuts. I have two of the big boards, but they are not running right now. If I remember correctly the big ones are more of a cost reduction model compared to the 2 board split solition. Giving lower SV snr than the split version. But my ran just fine compared to my standard Tbolts. -- Björn Skickat från min Mobil Originalmeddelande Från: gandal...@aol.com Datum: 2013-08-01 11:09 (GMT+01:00) Till: time-nuts@febo.com Rubrik: Re: [time-nuts] Trimble Nortel GPSTM Boards Hi Charles Thanks for your comments, the surveyed position on this is looking pretty good but what I have now realised is that the severity of the jumps seems very much related to the number of sattelites being tracked. Switching from 8 to 7, or 7 to 8, sats seems to produce the biggest step change whilst switching in either direction between 5 and 6, for example, doesn't seem to show up at all on the monitored DAC voltage. Ok, I take that back, it does still seem to depend on the number of sats being switched between but I've just seen a switch from 5 to 4 sats induce a very noticeable step change in DAC voltage, so the relationship doesn't appear to be linear. Unfortunately I need to power this down now for a few days but will investigate more later. Regards Nigel GM8PZR In a message dated 01/08/2013 09:45:24 GMT Daylight Time, charles_steinm...@lavabit.com writes: Nigel wrote: at times I'm seeing very noticeable step changes in the DAC voltage on this one as that happens. * * * I am a bit surprised by the extent, a Mark Sims online plot from 2012 shows some correlation on an NTGS50AA but not as noticeable as this, and I don't recall seeing anything quite so pronounced on a Thunderbolt. IME (with TBolts), the magnitude of the DAC steps with constellation changes varies with the accuracy of the positional data used by the GPS. To a point, the more accurate the survey, the smaller the DAC jumps will be. (Other errors prevent reducing the constellation-change DAC steps to zero.) Mark has commented here on survey accuracy, and the methods he used in Lady Heather to maximize it. Best regards, Charles ___ 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 Nortel GPSTM Boards
I am seeing the same thing -- big jumps every single time a satellite is counted or not. Elevation mask 10 degrees, which should be very good and stable for my location. The unit also insists on converging to a bat altitude, then after a while declares stored position bad . .. then declares position good, even with bad altitude. Ideas appreciated. jimwb4...@amsat.org On 8/1/2013 6:31 AM, Bob Camp wrote: Hi You may have your elevation mask set to low for your antenna or a multi path issue from some other source. If the survey location is good to under a meter and the signals are good, there should be very little shift as sats are picked up or dropped. Bob On Aug 1, 2013, at 5:09 AM, gandal...@aol.com wrote: Hi Charles Thanks for your comments, the surveyed position on this is looking pretty good but what I have now realised is that the severity of the jumps seems very much related to the number of sattelites being tracked. Switching from 8 to 7, or 7 to 8, sats seems to produce the biggest step change whilst switching in either direction between 5 and 6, for example, doesn't seem to show up at all on the monitored DAC voltage. Ok, I take that back, it does still seem to depend on the number of sats being switched between but I've just seen a switch from 5 to 4 sats induce a very noticeable step change in DAC voltage, so the relationship doesn't appear to be linear. Unfortunately I need to power this down now for a few days but will investigate more later. Regards Nigel GM8PZR In a message dated 01/08/2013 09:45:24 GMT Daylight Time, charles_steinm...@lavabit.com writes: Nigel wrote: at times I'm seeing very noticeable step changes in the DAC voltage on this one as that happens. * * * I am a bit surprised by the extent, a Mark Sims online plot from 2012 shows some correlation on an NTGS50AA but not as noticeable as this, and I don't recall seeing anything quite so pronounced on a Thunderbolt. IME (with TBolts), the magnitude of the DAC steps with constellation changes varies with the accuracy of the positional data used by the GPS. To a point, the more accurate the survey, the smaller the DAC jumps will be. (Other errors prevent reducing the constellation-change DAC steps to zero.) Mark has commented here on survey accuracy, and the methods he used in Lady Heather to maximize it. Best regards, Charles ___ 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. ___ 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 Nortel GPSTM Boards
Buggy firmware? Anyone seen the firmware floating around? -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Jim Sanford Sent: Friday, 2 August 2013 10:46 AM To: time-nuts@febo.com Subject: Re: [time-nuts] Trimble Nortel GPSTM Boards I am seeing the same thing -- big jumps every single time a satellite is counted or not. Elevation mask 10 degrees, which should be very good and stable for my location. The unit also insists on converging to a bat altitude, then after a while declares stored position bad . .. then declares position good, even with bad altitude. Ideas appreciated. jimwb4...@amsat.org On 8/1/2013 6:31 AM, Bob Camp wrote: Hi You may have your elevation mask set to low for your antenna or a multi path issue from some other source. If the survey location is good to under a meter and the signals are good, there should be very little shift as sats are picked up or dropped. Bob On Aug 1, 2013, at 5:09 AM, gandal...@aol.com wrote: Hi Charles Thanks for your comments, the surveyed position on this is looking pretty good but what I have now realised is that the severity of the jumps seems very much related to the number of sattelites being tracked. Switching from 8 to 7, or 7 to 8, sats seems to produce the biggest step change whilst switching in either direction between 5 and 6, for example, doesn't seem to show up at all on the monitored DAC voltage. Ok, I take that back, it does still seem to depend on the number of sats being switched between but I've just seen a switch from 5 to 4 sats induce a very noticeable step change in DAC voltage, so the relationship doesn't appear to be linear. Unfortunately I need to power this down now for a few days but will investigate more later. Regards Nigel GM8PZR In a message dated 01/08/2013 09:45:24 GMT Daylight Time, charles_steinm...@lavabit.com writes: Nigel wrote: at times I'm seeing very noticeable step changes in the DAC voltage on this one as that happens. * * * I am a bit surprised by the extent, a Mark Sims online plot from 2012 shows some correlation on an NTGS50AA but not as noticeable as this, and I don't recall seeing anything quite so pronounced on a Thunderbolt. IME (with TBolts), the magnitude of the DAC steps with constellation changes varies with the accuracy of the positional data used by the GPS. To a point, the more accurate the survey, the smaller the DAC jumps will be. (Other errors prevent reducing the constellation-change DAC steps to zero.) Mark has commented here on survey accuracy, and the methods he used in Lady Heather to maximize it. Best regards, Charles ___ 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. ___ 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 Nortel GPSTM Boards
Having stuck a late bid on a recent auction for what I'd assumed was a Trimble Nortel NTGS50AA I then realised I'd just bought the single board version, part number 4500-00-CH with the Trimble 49422-CR OCXO. That in itself wasn't a problem, except perhaps the doubts cast over my sanity:-), it arrived earlier today and has been running for several hours now, chatting comfortably with Lady Heather, and generally settling in nicely. However, it does prompt the question, has anyone had a chance to compare one of these side by side with an NTGS50AA and, if so, were there any obvious differences in performance? Regards Nigel GM8PZR ___ 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 Nortel GPSTM Boards
Hi From looking at a picture of one, it seems to have all the same stuff on it as the NTGS50 era gizmos. It should behave the same way. Bob On Jul 31, 2013, at 5:42 PM, gandal...@aol.com wrote: Having stuck a late bid on a recent auction for what I'd assumed was a Trimble Nortel NTGS50AA I then realised I'd just bought the single board version, part number 4500-00-CH with the Trimble 49422-CR OCXO. That in itself wasn't a problem, except perhaps the doubts cast over my sanity:-), it arrived earlier today and has been running for several hours now, chatting comfortably with Lady Heather, and generally settling in nicely. However, it does prompt the question, has anyone had a chance to compare one of these side by side with an NTGS50AA and, if so, were there any obvious differences in performance? Regards Nigel GM8PZR ___ 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.
