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.