Table of contents
20.1.2017
DBBC3: Installed the DBBC3 into the VLBI rack. Two Mark6 recorders (pv-mark6-1 and pv-mark6-2) have been designated to record from the DBBC3. pv-mark6-3 and pv-mark6-4 will be connected to the R2DBE equipment. One of the glass fibre cables brought to Pico turned out to be defective. The fibre from the internal FiLA10G installed in the DBBC2 was used as a temporary replacement. Recording was not successful due to problems with pv-mark6-1 and pv-mark6-2.
Installing DBBC3:
- Unpacked and reassembled DBBC3, no visible damage
- 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
