In article <[EMAIL PROTECTED]>, Uwe Klein <[EMAIL PROTECTED]> wrote:
> Joseph Gwinn wrote: > > In article <[EMAIL PROTECTED]>, > > Uwe Klein <[EMAIL PROTECTED]> wrote: > > > > > >>Joseph Gwinn wrote: > >> > >>>I may need a Dual Mixer Time Difference (DMTD) instrument, to measure > >>>picosecond changes in electrical length in a coax plus amplifier time > >>>reference signal distribution system with total delays in the hundreds > >>>of nanoseconds, currently operating at 10 MHz (sinewave), but with 100 > >>>MHz likely at some future date. > >>> > >>>What DMTD instruments are commercially available? A google search was > >>>not successful - all noise no detectable signal, probably because DMTD > >>>instruments are not that common, and many people build their own. > >>> > >>>Thanks, > >>> > >>>Joe Gwinn > >> > >>Take one of the "better" GS DSO's that have high storage depth. > >>Read the shots from the DSO and do all further processing in software? > > > > > > I don't understand how this would work. Could you expand the > > description? And what is "GS"? > GS as in GigaSample > > > http://www.unusualresearch.com/AppNotes/TimeNuts/OptDualMixer.pdf > http://www.wriley.com/paper6ht.htm > > if my understanding is correct: > take a large syncronous sampling of both signals. > extract the data. > retrace in software the math done in hardware on the aquired data set. > i.e. if you do a soft mixdown to DC you should get two vectors (R/I) > describing the phase relationship between both signals. OK. It sounds like what the 5120 does. I be that there are a lot of details to get *exactly* right, though. Joe Gwinn _______________________________________________ questions mailing list [email protected] https://lists.ntp.org/mailman/listinfo/questions
