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
