> That's what I was intending doing, although the adjustment as far > courser than ideal on a counter with 11 digits.
Many of us use HP 5370A/B's as *time interval* counters; typically to precisely compare two 1 PPS sources. In this case the 25 ps rms single-shot resolution of the counter is the key feature, not the 11-digit display, nor even the quality of the timebase. You're 10811 OCXO can be off by huge amounts and you can still get perfectly accurate 1 PPS TI measurements. As a example, roughly speaking, if you tune your 10811 today to be accurate to 11 digits, it will be down to 10 digits by the day after tomorrow, to 9 digits after a week, only 8 digits by the end of the month, and 7 digits by the end of a year. There is a good chance it will still be accurate to 6 digits (1 ppm) after 10 years. Still, even when off by as much as 1 ppm (e.g., ten years since calibration), if the 1 PPS time intervals you are measuring are down in the microseconds -- as would typically be the case when comparing Rb, Cs, or GPS references -- your tired old 5370B will continue to give you perfect readings. 6 digits of accuracy is more than enough when measuring time intervals with 25 ps of resolution and under 10 microseconds in range. /tvb http://www.LeapSecond.com _______________________________________________ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
