Could not reach Pcal folks to confirm SDF differences. Accepted the differences (see file below) to get back to Observing.
These changes are standard.
In other words: The temporary PCALX calibration lines that had been running for a few days (LHO aLOG 37952) were switched OFF the other day (see LHO aLOG 38148). There are many ways to do so, but that day they chose to zero out the "oscillator use" matrix which sums all PCALX oscillators as desired. Element 1_1 has been traditionally reserved for the high-frequency roaming PCAL line used for Sudarshan's thesis. It was turned back "ON" by putting a 1.0 in the matrix. However, there's no gain on the oscillator, so nothing's coming out. Elements 1_2 and 1_3 were for the 333.9 Hz and 1083.3 Hz lines, which have now been zeroed. The reason these showed up as an SDF difference in the OBSERVE snap was because these lines had been running during observation ready data for the past few days. So accepting this values above are just accepting that they are turned OFF.