I have done this and I am not sure I can tell the 'direction of rotation'. I can easily tell if it reverses but once going, I can't tell which direction.
Joe -----Original Message----- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of J. Forster Sent: Monday, August 03, 2009 11:14 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Method for comparing oscillators Rather than using a scope in Y-T mode (with triggered sweep) I find that using a scope in X-Y mode makes it much easier to compare frequencies. Doing this, you essentially get a synchroscope display. If the two waveforms are sinusoidal, the trace will be a circle, the rate of revolution is the frequency difference, the direction of rotation tells you which frequency is high/low. FWIW, -John ======= > John, > [snip] > Your oscilloscope method (without proper handling of phase > ambiguities) measures a compound of both properties and is not well > suited for stability measurements. [snip _______________________________________________ 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.