Weather Conditions:
- Humidity: 73-81%
- Wind: 0-6 mph avg winds
- Skies: cloudy-clear
- Lowest temp: 38 deg F, 3.3 deg C
Errors/Issues:
- Rx4 IFLO module was changed today by Peter. Servos did not get Rx4 X-Pol IFLO values to target. Railing the voltage by hand still did not produce close to desired IF/LO values. Power looked okay at first, then during the first track it dropped to ~-28 dB and IF/LO values changed dramatically. After first track, ran servos on just Rx4 X-Pol to try and fix it. It worked for a little while and then power dropped again, to ~-16 dB. Rx5 X-Pol power also dropped to about -15 dB, but it improved later in the night.
- Rx1 X-Pol power looked good after servos but I channel power went up to ~-9 dB during first track
- Jupiter was only 5 degrees away from the moon tonight. This could have been the cause of some of the power issues, but the worst issues were observed only on X-Pol, and some issues persisted even after slewing away from Jupiter and the moon.
- Had a ptc socket error at 11:20 pm HT that ended the 3rd Q2343 main track early.
- While troubleshooting the ptc socket errors, and the initial power cycling of ptc did not work, encountered a jack 1 brake failure while attempting to put the telescope into neutral position. This failure is serious enough that further observations were cancelled until Peter can take a look at the hexapod.
Executed Runs:
- 10 min Jupiter multi-source track processed as primary calibrator
- 40 min Jupiter offset track for alignment
- 15 min 2253+161 Q2343 IM target calibrator track
- 45 min Q2343 repeated no ccd IM target track
- 15 min 2253+161 Q2343 IM target calibrator track
- 45 min Q2343 repeated no ccd IM target track
- 15 min 2253+161 Q2343 IM target calibrator track
- 45 min Q2343 repeated no ccd IM target track (incomplete due to ptc socket error)
|
|
|
|
|
|
-Casandra, Adam
Rx4 warmed up and is currently being pumped down and will be cooled down on Tuesday. Its raising temperature may have caused the IF power to decrease to -28 dBm durning the Thursday night observations. If Rx4 cools down properly on Tuesday, I will check the power levels so the it can reach its target values.
I also tested the servo drives to see if the Jack #1 brake failure would come back. It did not come back so Adam and Casandra can do Tuesday and Thursday night observations this week.
This Jack#1 brake failure may be intermittent so it may come back, but if you press the “reset failure” button it will clear the error and observations can continue. But if it continues to come back then observations will have to stop and the problem needs to be looked at.
Peter
Did you notice why Rx4 Y-pol had little power? Or is it due to adjusting the X-pol servo manually?
Here’s the SEFD results from the Jupiter offset:
## antenna SEFD: (MJy)
Ant0 Ant1 Ant2 Ant3 Ant4 Ant5 Ant6
X-pol:
LSB:: 0.62 0.60 0.64 0.81 nan 0.69 0.69
USB:: 0.63 0.58 0.61 0.72 nan 0.63 0.66
Y-pol:
LSB:: 0.61 0.70 0.60 0.74 87.56 0.65 0.66
USB:: 0.59 0.70 0.54 0.70 80.52 0.58 0.63
Alignment after removing Rx4Y from the analysis:
# Ant Shim(S,N,E/W) Align_R Align_D
X-pol:
Ant0 S 0.0007 N 0.0054 E 0.0000 0.92 -1.65
Ant1 S 0.0013 N 0.0000 E 0.0009 -0.02 0.44
Ant2 S 0.0016 N 0.0019 E 0.0000 0.64 -0.21
Ant3 S 0.0011 N 0.0000 E 0.0008 -0.04 0.36
Ant4 S nan N nan E nan nan nan
Ant5 S 0.0000 N 0.0001 E 0.0006 -0.21 -0.01
Ant6 S 0.0029 N 0.0000 E 0.0033 -0.56 1.03
Y-pol:
Ant0 S 0.0010 N 0.0061 E 0.0000 1.09 -1.83
Ant1 S 0.0011 N 0.0000 E 0.0004 0.09 0.35
Ant2 S 0.0015 N 0.0017 E 0.0000 0.59 -0.15
Ant3 S 0.0014 N 0.0000 E 0.0010 -0.04 0.45
Ant4 S nan N nan E nan nan nan
Ant5 S 0.0000 N 0.0008 E 0.0011 -0.28 -0.24
Ant6 S 0.0028 N 0.0000 E 0.0032 -0.54 1.01
Could we adjust Ant0 before next observation? Ant6 looks OK.
— Kyle
Hi Kyle,
I will adjust the shims for Ant0 on Tuesday.
As for the low power on Rx4, it could be due to the adjustable LO power need to be set for more power output. I could have moved the adjustable knobs when I was installing the IF/LO module last week.
Peter