TGBT14A_912_11 - VEGASDM jump tests


  • Try and isolate cause of VEGAS DM jumps, and Bank H balancing problems


  • Try mode 11, this failed to balance VEGAS before. Take out data acquisition step.
  • Fails to balance. Steve investigates CM16 is dead - this explains the problem.

  • NB - don't seem to get drop-outs when scan is not running...
  • Run RRLMode10SP - this should show drop-outs. Run an archivist sampler on Bank A - can't find any!
  • Scan 1 RRLMode10SP - spike is present in both sampler and VEVGASDM. So, it is not a VEGASDM problem.
  • Try running with Bank A looking at the noise source
  • Scan 2 RRLMode10SP - Bank A noise source - still see -ve going spikes
  • Try and get an archivist running - edit RRLMode10SP _Archivist
  • Scan 3 - Bank A now looking at astronomical signal again. Still get a spike. Is it present in the data?
  • Try and run mode 1 with highest possible data rate, and see whether we still get spikes.
  • With Doppler Tracking turned on; can only go as fast at 0.2 secs; try this.
  • Scan 4 RRLMode1SP _archivist - still shows drop-outs.
  • Turn off Doppler tracking, and put integration time to 0.1 secs. Add archivists on all Banks
  • Scan 5 RRLMode1SP _archivist (all 8 banks). No drop-outs. Must be related to Doppler tracking?
  • Turn Doppler tracking back on again; 0.2 sec integration times
  • Scan 6 RRLMode1SP _archivist - dropouts (Bank B, Bank A, Bank D, Bank B, Bank C).
  • Go back to the noise source in all banks
  • Scan 7 RRLMode1SP _archivist - dropouts (Bank G - one pol, again, Bank F +ve, Bank D, Bank F)
  • Scan 8 RRLMode1SP _archivist - dropouts (Bank E, Bank D)
  • Switch back to Mode 10 where we seemed to get more dropouts.
  • tp_nocal, 0.1s integrations
  • Scan 9 - RRLMode1SP _archivist by mistake
  • Scan 10 - RRLMode10SP _archivist - aborts
  • Scan 10 - aborts again - why? - continue the scan - seems ok? - LO1? No data is taken, but no dropouts.
  • Scan 10 RRLMode10SP archivist in _TP mode_ aborts again - what is going on here? LO1 is screwed up
  • Scan 10 RRLMode10SP archivist in _TP mode_ (with cal)
  • Turn Doppler tracking back on again; 0.2 sec integration times - Mode 1
  • Scan 11-13 RRLMode1SP _archivist External Noise source in both Pols of Bank A (five iterations)
  • Drop-outs Bank F, C, B, G, E, D, H - seems quite convincing. Switch to Mode 10, which has more dropouts
  • Scan 14-15 RRLMode10Sp_archivist - Dropouts B,C,D,E,F,G,H - no A
  • I'm convinced. Stop here
Topic revision: r2 - 2015-01-27, RichardPrestage
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