2017 August
Aug 10
02:10 UT After many days of the system running normally, we had a glitch today that I did not notice until this evening. The ROACH clock was messed up...so we took a lot of very short files since 16:03 UT on Aug. 09. Luckily, I was able to get the clock working again, and I should be able to bring the system up and reset delays, etc.
02:17 UT Well, we are on 3C273 and tracking, so it was a fast recovery. I will take data for 20 min or so and set the delays. 3C273 will set soon, but I should be able to check delays on 3C286, at least to see if they are rational. One thing I will need to check is whether the X-Y delays change as a result of rebooting the ROACHes. I will set up to observe 2253+161 and do an X-Y delay calibration.
02:58 UT Not bad! I got the delays reset from the 3C273 observation, and will take my X-Y delay measurements starting at 08:25 UT, both with low and high receivers. However, I have not set the low-receiver delays. Ant 14 may be off by 2 ns as a result (it was on the high receiver).