Table of contents
- 1. 27.01.2017
- 2. 26.01.2017
- 3. 24.01.2017
- 4. 23.01.2017
- 5. 22.01.2017
- 6. 21.1.2017
- 7. 20.1.2017
27.01.2017
DBBC3: Checked the stats of DBBC3 after letting it run over night with covers mounted, it lost synchronization in the first sampler of the first module. After resetting samplers it immediately lost synchronization again. Removed covers and let it cool down for 30 minutes. With covers removed DBBC3 was running stable for the whole day.
Recalibrated DBBC3 with ambient load from antenna as noise, powerlevel and stats from samplers had very good values.
26.01.2017
24.01.2017
DBBC3: Made Zero-Baseline Tests with modules 1 and 2, including down-conversion (6 GHz tone injected).
23.01.2017
DBBC3: Further testing and recording, made some modifications to the control software to improve calibration accuracy and speed.
22.01.2017
DBBC3: After reattaching the SMA connector to IFA 0-4 GHz input, the connector on the GCoMo side got loose,.This caused an SMA cable in the GCoMo to get ripped of. We were able to find a replacement cable and repair the GCoMo. We replaced the snap-rings to prevent further loosening of the connectors.
Tested modules 3 and 4, found that sampler 2 of module 3 is hanging, sending only FFFs to the Core3H. This was not the case in the lab in Bonn, suspected that the connectors got damaged during transport or reassembling. Checked the 140-pin connectors under the microscope, some of the pins have almost no soldering. Since modules 1, 2 and 4 are working fine and only two modules are needed for run in April, we dediced to leave it that way until after the run.
21.1.2017
Mark6 ethernet: pv-mark6-1 lost 10G network connection occasionally. Inspection showed that this is only affecting the two ethernet ports of the card being close to the chassis edge. This is very likely due to the transceivers becoming critically hot due to bad airflow within the mark6 chassis. As a workaround the transceivers were placed into pv-mark6-3 as it is closer to the floor with lower ambient air temperature. The mark6 machines were taken from the rack and the network cards were rearranged (closer to the middle and leaving a one-slot gap between them).
Mark6 installation: installation of the 2015 version of the mark6 software was finished on pv-mark6-3 and pv-mark6-4. The system time was set to UTC and the proper NTP functionality was verified. On pv-mark6-4 a problem occured when trying to open a group (permission problem on /mnt/disk/?/? tree). Deleting the /mnt/disks tree and recreating it by hand has solved the problem.
DBBC3: Testing of DBBC3 was continued with recordings on mark6. Recording only works if correct MAC-Addresses are set in Core3H-Config-Files. Recording was done with noise and 4.5 GHz line, to test down-conversion, which is working as expected.
20.1.2017
DBBC3:
- Unpacked and reassembled DBBC3, no visible damage
- One of the fibre cables for connecting the mark6 turned out to be defective. Used the fibre of the DBBC2 FiLA10G board as a temporary replacement.
- Installation and first testing of DBBC3:
- The powerlevel of 10 MHz had to be adjusted (should be between 0 and 3 dBm)
- recalibration: levels of gain, offset and delay were as expected, only small adjustments necessary
- connected 2-18 GHz noise source on 4-8 GHz input of IF A and IF B, we had to use 3 dBm attenuators on input to get power levels in good range for DBBC3:
- agc target value 28000
- results in attenuation 15 to 16 dBm in GCoMo with agc on.
- GPS timesync working fine
