Ahhh, I see what you mean because a few pages later there is word of a "phase accumulator". But this phase accumulator is a part of the electronics that is responsible for generating the control voltage of a VCO that enables the device to produce odd frequencies despite the integer dividers in the main loop. That IS different from what a phase accumulator's task is in a DDS.
73s de Ulrich, DF6JB > -----Ursprungliche Nachricht----- > Von: time-nuts-boun...@febo.com > [mailto:time-nuts-boun...@febo.com] Im Auftrag von Ulrich Bangert > Gesendet: Dienstag, 25. Januar 2011 15:35 > An: 'Discussion of precise time and frequency measurement' > Betreff: Re: [time-nuts] An (unknown?) nasty feature of the > DDS principlefor time nuts applications > > > Gerhard, > > see page 8.6ff of the service manual to see that the HP3325 > is not DDS based but uses a "Fractional N Synthesizer scheme" > which is something completely different and is not prone to > the described effects. Nevertheless it is true that the > HP3325 contibutes phase noise to the measurement but I had > anticipated that this was clear to everybode in the auditorium. > > 73s de Ulrich, DF&JB > > > -----Ursprungliche Nachricht----- > > Von: time-nuts-boun...@febo.com > > [mailto:time-nuts-boun...@febo.com] Im Auftrag von dk...@arcor.de > > Gesendet: Dienstag, 25. Januar 2011 15:14 > > An: time-nuts@febo.com > > Betreff: Re: [time-nuts] An (unknown?) nasty feature of the > > DDS principle for time nuts applications > > > > > > > > Don't forget that your HP3325 is DDS-based, too, so it adds > > its own phase error sawtooth. > > > > 73, Gerhard dk4xp > > > > > > _______________________________________________ > > 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.