Didier Juges wrote: > I guess it depends on signal to noise ratio. With reciprocal counters, you > only need one period to measure as acurately as you need, but to have good > acuracy, you need very good S/N, as there is no filtering possible. > > For example, the HP 5370 can measure a single period of a signal with a > resolution of 20pS (excluding noise and trigger imperfections), so excluding > these errors, the HP 5370 could measure a single period of a ~3.5 MHz signal > with 7 x10-5 precision (if I have not goofed the calculations....) More > periods improve the resolution proportionately to the quare root. Accuracy > is another matter. > > Didier KO4BB > Didier
With band limited gaussian noise and an SNR of 40dB the rms error in measuring the period of a single cycle is about 0.3% Bruce _______________________________________________ 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.