VEGAS Team Meeting

434-817-6443# (telephone)

Attendees: Mark, Ray, Adam, Joe, Sam, Paul, Marty, Jason, John, Richard, Randy, Anish


  1. Status of MMCM calibrated BOFs for modes 2 & 3
  2. Status of “Spikes” in all modes
  3. "Top Hat" situation
  4. IF passband into ADC for Modes 1,2,& 3 [Watts] - Done?
  5. Test Time

Meeting notes:

  1. Status of MMCM calibrated BOFs for modes 2 & 3
    • Potential cause of poor baseline performance in tests by D. Frayer.
      • Temp data
      • stabilize by keeping door closed for a while before calibrations
      • Dave to do Mode 1 <--> Mode 2 comparison
        • Care needs to be taken to be sure all the external parameters are the same for both tests
  2. Status of “Spikes” in all modes
    • Next steps
      • Try the shift setting tests recommended (ffff v. aaaa)
      • no indication of underflow/overflow in "ffff v. aaaa" test (mode 4)
        • Changed profile but hard to see any improvement. Power in passband lower on 'low side' and that is where spikes are evident.
    • [Done] Recheck OGP(?) calibrations on the next maintenance day
      • review the discussion last week concerning ADC calibration - did not have effect on spikes
    • Need UCB to offer up fix - Marty to request status update
    • Fix build environment (NRAO & UCB)
  3. "Top Hat" situation
    • Case last night where it wasn’t 1024 pixels wide (128 pixels wide in each subband (4) of 8-subband mode).
    • Is a software work-around to detect the top hat and force a reset possible? (To avoid lost time from observers not checking their data).
      • Should be able to detect in manager and trigger an abort which should trigger notification
      • Also when scan is shortened
  4. IF passband into ADC for Modes 1,2,& 3 [Watts] -
    • Passbands look good
  5. Test Time
    • Wednesday
      • ADC Re-calibrations [Ray, Marganian]
      • VEGAS Mode 1 <--> Mode 2 comparison (after ADC recal) [Frayer]
  6. Other

-- MartyBloss - 2014-09-08
Topic revision: r2 - 2014-09-08, MartyBloss
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