I recently bought an HP 8720D 20 GHz VNA with options 010 (TDR facility) and 1D5, which is the high stability time base. It's a fairly old VNA (not supported since 2004), but it's not exactly a dinosaur
Accuracy (23 deg C +/- 3 deg C) 10 ppm The standard oscillator specs are: Stability 0 - 55 deg C 7.5 ppm Ageing per year = +/-3 ppm The high stability time base, option 1D5 are: Stability 0 - 55 deg C +/- 0.05 ppm Ageing +/- 0.5 ppm Resolution 1 Hz. What is likely to be the difference in design between the standard and high stability oscillators? It seems that while the optional timebase is more stable, this does not appear to reflect in the accuracy of the instrument, which is specified as 10 ppm. Perhaps that's due to the fact that the steps are 1 Hz, and the synthesiser can't generate exactly 1 Hz steps. I don't know. You guys know more than me! dave _______________________________________________ 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.
