2017 October: Difference between revisions
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'''15:45 UT''' I checked the Ant 10 delays, and strangely the HPol delay was changed by 3 ns, but not VPol. That means there is an new X vs. Y delay. I updated all of the delays (minor changes to a few antennas, but no other X-Y delay differences). Ant 10 data will be compromised since Tuesday, Oct. 3. I restarted the solar scan at 15:45 UT. I will redo the X-Y delay calibration tonight. | '''15:45 UT''' I checked the Ant 10 delays, and strangely the HPol delay was changed by 3 ns, but not VPol. That means there is an new X vs. Y delay. I updated all of the delays (minor changes to a few antennas, but no other X-Y delay differences). Ant 10 data will be compromised since Tuesday, Oct. 3. I restarted the solar scan at 15:45 UT. I will redo the X-Y delay calibration tonight. | ||
= Oct 12 = | |||
'''20:05 UT''' Last night I loaded a new design of Jack's 300 MHz correlator. It did not work--some sort of sync problem in collecting the X packets, but at least all of the packets showed up. I reloaded the 200 MHz correlator and went through the procedure to update the delays again. An overnight test shows the delays are okay. On another topic, Ant 12 has some sort of pinion gear failure, so that it did not track correctly in Az (apparently it was oscillating wildly). Kjell is working with InterTronics about it. It will be out of the array until fixed. This all started on Oct. 10, I believe. | |||
Revision as of 20:12, 12 October 2017
Oct 05
13:00 UT Kjell changed the VPol optical transmitter in Ant 10 on Tuesday (Oct 3), and I finally had time to check it. I find that it solved the problem of the rapid fluctuations we had been seeing for some time (present at least since the Sep. 10 X-flare, but possibly well before. However, the levels for Ant10 VPol were low, so I have updated both the FEM and DCM level settings (for all antennas), which I hope will solve the problem. All gain/attenuation calibrations will now be different for data after this time, although it should all be handled automatically.
15:45 UT I checked the Ant 10 delays, and strangely the HPol delay was changed by 3 ns, but not VPol. That means there is an new X vs. Y delay. I updated all of the delays (minor changes to a few antennas, but no other X-Y delay differences). Ant 10 data will be compromised since Tuesday, Oct. 3. I restarted the solar scan at 15:45 UT. I will redo the X-Y delay calibration tonight.
Oct 12
20:05 UT Last night I loaded a new design of Jack's 300 MHz correlator. It did not work--some sort of sync problem in collecting the X packets, but at least all of the packets showed up. I reloaded the 200 MHz correlator and went through the procedure to update the delays again. An overnight test shows the delays are okay. On another topic, Ant 12 has some sort of pinion gear failure, so that it did not track correctly in Az (apparently it was oscillating wildly). Kjell is working with InterTronics about it. It will be out of the array until fixed. This all started on Oct. 10, I believe.