ATNF VLBI Wiki

Mopra 12mm setup at 22316 MHz. Circular polarisation setup via a C-band IF hybrid was done on Mon 4/2/08. A small LCP helix was used to inject a test-tone and adjust the hybrid to give RCP & LCP. Relevant settings:

• mm RF (module F14) attenuations MUST stay fixed at 13,11 dB (for the 2 IFs). The conversion racks attenuators were set to: coarse 0000 ; fine 5445 but these may be adjusted.

• C-band Hybrid setup values on rotary pots. Initial values == Atten=17.17; Phase=26.68. This gave a nominal 17 db isolation but the Tsys was assymetric (120K ; 80K). The phase was readjusted to equalise the Tsys (~100K on both) but the nominal separation fell to ~11dB. ** Final values:: Atten=17.17; Phase=25.90

• Recording to ATNF V006A

Onsource at 09:10 UT

12:50-13:10 UT windstow due to storm. High Tsys.