); SAEximRunCond expanded to false Errors-To: [EMAIL PROTECTED] RETRY > 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
The jitter on a single period is likely very, very high, especially if it comes over the air. That's why one usually measures over a duration of thousands or even millions of periods (effectively called the gate time). The HP 53132A makes something like 200,000 measurements per second. As a result, for a certain range of frequencies, it claims 12 digits/sec of resolution (vs. HP 5370 ~11 digits/sec). /tvb _______________________________________________ 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.
