They make frequency difference meters. I never used one, but it seems to me a frequency difference meter would just use the two input signals to toggle up and down respectively on a counter, then display the result over a fixed period.
Would this do what you want? ------Original Message------ From: Hal Murray Sender: time-nuts-boun...@febo.com To: time-nuts@febo.com ReplyTo: Discussion of precise time and frequency measurement Subject: [time-nuts] Comparing PPS from 2 GPS units Sent: Dec 13, 2012 1:57 AM Suppose I want to compare the PPS outputs of 2 GPS units. The problem is that I don't know which one will happen first. If I feed them into the start/stop inputs of a typical timer/freq box, I don't know which is which. If I get them wrong, the answer will be 0.999999xx seconds rather than the -0.000000xx that I want. Is there a simple solution for this? My straw man is to use the antenna cable delay setting to offset one of the PPS pulses a long way. Plan B would be a physical delay unit. But they are probably temperature sensitive, and I'm not setup to keep anything at a constant temperature. Do any of the counter/timer boxes have a mode for this? If so, is there a buzzword I've overlooked? -- These are my opinions. I hate spam. _______________________________________________ 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.