N8UR-1 Stability Data

This page shows the results of a 48 hour comparison between my HP Z3801A GPS-disciplined crystal oscillator (denoted "N8UR-1") and my HP 5065A rubidium frequency standard (denoted "N8UR-3").

There are four charts shown below. The first is the raw phase comparison over the 48 hour logging period.

The second is the phase with the approximate 1.3x10-12 frequency offset of N8UR-3 (as determined via contemporaneous comparison with LORAN-C (8970M), and its small aging rate, removed. This chart is a good representation of the actual difference between the two oscillators.

The third chart is a plot of the Allen Variance of N8UR-1 as compared to N8UR-3. Because of limitations in my current measurement system, please ignore the values below 100 seconds.

The fourth chart is a measurement of the Allen Variance at all measurement intervals. The value of this chart is that it will highlight any deterministic effect, such a temperature cycle.