Yes, the error is greater... then maybe the clock of the NCO is not the chipping rate. In the FTS125 the clock for the RX is sourced by a 20MHz OFC5DJ3 fixed OCXO but this doesn't imply that the CW12 has a 20MHz clock... at the moment no other clue comes to mind.
On Wed, Jan 4, 2012 at 5:35 PM, Ed Palmer <ed_pal...@sasktel.net> wrote: > On 1/4/2012 9:00 AM, Azelio Boriani wrote: > > The output frequency is programmable: try $PRTHS,FRQD,xx.xxx<cr><lf> >> where >> xx.xxx is the desired(?) frequency in MHz with 3 decimal places (they say >> for 10KHz set 0.010). >> > > Unfortunately, the frequency is programmable only with the NMEA software > load. I'm using the Motorola load. If I reflashed to the NMEA load I'd > lose the TRAIM functionality. In any case, the setting doesn't have nearly > enough resolution to correct such a small error. > > > Maybe the slight offset is due to the NCO based on the chipping rate of >> 10.23MHz: >> >> 10.23MHz/2^32*4198404003 is 9.99999999783MHz >> > > Your calculation gives an error of 2.17 mHz. I measured an error of .15 > mHz. I tried playing with variations on your calculation but couldn't find > one that fit. It would be interesting to find out why the error exists, > but I don't think we will ever know for sure. > > Ed > > > > _______________________________________________ > 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.