Hi That was actually talking about a heterodyne system.
Indeed a good digitizer could be used with a DMTD. One thing I have not looked into is the DC accuracy required if you go that way. Some of these approaches have odd little gotcha's. By analogy with a heterodyne setup it might not. That's not always the best way to analyze things .... Bob On Feb 7, 2010, at 3:50 AM, Magnus Danielson wrote: > Bob Camp wrote: >> Hi >> I believe the statement: >> "Both systems are equally limited by the reference oscillator" was part of >> the same paragraph as the comment on 10811 short term stability. >> Neither system, no matter how well set up will get below the stability of >> the reference oscillator. > > For DMTD systems the transfer oscillator noise can be partially cancelled. > You do have two inputs, but you then play three-cornered hat tricks. However, > for a DMTD system to be able to cancel noise, good time-correlation between > channels is needed to make the noise-integration time-periods of both > channels to match up. The more they are apart, the bigger difference in noise > it is between the channels and thus it will fail to cancel. Thus, > phase-alignment prior to ZCDs could be a treatment. Using the audio channel > approach avoids the issue as the full-wave signal is being used and time > correlation between samples is high, an approach not available when DMTD was > developed. > > Cheers, > Magnus - while visiting fellow time-nut > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
