SudarshanK, DarkhanT, TravisS, RickS

Yend calibration measurements were performed on 10/31/16 using the WS1 working standard.  The results of those measurements were used to generate the calibrations for the Pcal Rx and Tx power sensors.

On 11/9/16 we repeated the measurements using a new working standard, WS3, because WS1 was accidentally dropped on the concrete floor, changing it's responsivity.  We decided to retire it and replace it with WS3.  The time series for these measurements revealed that the peak-peak variations were sevaral times higher than usual.  The power sensor calibrations differed from the earlier measurements by as much as 0.5%.  The power source to which the WS electronics were connected was suspected to be the cause of the excess noise.  

On 11/15/16 (two days ago) we repeated the measurements with WS3 but with the WS electronics plugged into a different power source.  The signal variations returned to the expected values so it seems that the power source was the issue.

The new (previous) calibrations (N/V) are:

Tx: 1.5171e-9 (1.5160e-9) N/V (0.07% difference)

Rx: 1.0497e-9 (1.0475e-9) N/V (0.21% difference)

We will continue to use the "previous" values for the signal calibrations and make periodic checks during the oberving run at about 2-month intervals, as for all the end stations.