Alexa, Sheila

We saw that there was no signal on the PSL periscope PD, so we entered the PSL to investigate.  There is currently 170mW of light entering the periscope, and 0.7uW incident on the PD.  We measured the voltage from the PD using an osciliscope, it has a 13 mV offset and 4 mV of signal.  (both negative) This gives 0.38A/W, (we did not change the gain switch, so the gain setting should still be 15kOhms), and the pick off ratio (power on PD/power into HAM1) is 0.004.  These are not so different from the measurement Paul reported in alog 9865  We will stick with the old calibration which was made with more light on the diode.

We did not finish checking the calibration of this PD because there is also a problem with beckhoff.  Everything on corner chassis 3, 4, 5, and 6 is NO_COMM.  The problem with beckhoff was fixed by unplugging and reconnecting the cable between Corner Chassis 2+3, which could be a bad cable that needs to be replaced.