VEGAS testing (May 13, 2014)


  • Test to see whether manager fixes have gotten rid of the mode 1-3 ripple
  • Routing Q-band to banks A-D. Banks E-H not involved in test.


  • Project: TGBT13B _502
  • Session: 58

Scan Log:

  • Scan 1: RippleQbandmode1. VEGAS failed to balance. Balanced at -13dB. Went back through logs and this happened in previous runs as well. Balance is at same level. Must be a software update.
  • Scan 2: RippleQbandmode2.
  • Scan 3: RippleQbandmode3.
  • Scan 4: RippleQbandmode1. Running short mode 1 scan to get VEGAS in right state for Jason to check it.
  • Turned managers off so that Jason can check banks.
  • can see noise source in all banks except bank A. Bank C doesn't look any different
  • Connected test tone to banks A, B, C, and D in turn.
  • Ran check_spec on each bank and save image in /users/jray/
  • Bank A spikes are go up to -40 dB. Most of signal at -80 dB
  • Bank B spikes go up to -50 dB.
  • Bank C is symmetric, but huge spikes in center
  • Bank D looks okay.
  • Going to try to calibrate ADCs to see if this fixes things
  • turned on managers
  • Scan 5: RippleQbandmode1. configuring system so it's in the right state.
  • turned off managers so ADC calibration code can be run
  • configured ADC
  • turned on managers
  • Scan 6: RippleQbandmode1. 10minute scan.
  • turned off managers
  • turned on managers
  • loaded a new bof. So the ADCs weren't calibrated last run. Ray and Paul are going to get code working so we can run the system with the calibrated ADCs.
  • Amanda went to a two hour meeting while Ray was productive and rewrote the manager to accommodate our testing needs.
  • Scan 17: RippleQbandmode1. 10s scan
  • Shutting down samplers to recalibrate ADCs.
  • connected synthesizer
  • recalibrating ADCs
  • disconnected synthesizer and connected noise source.
  • scan 18: RippleQbandmode1. 5min scan
  • Booyah! no ripples
  • scan 19: RippleQbandmode1. 10min scan.
  • scan 20: RippleQbandmode2. 10s scan to change modes.
  • looks the same.
  • calibrating ADCs
  • scan 21: RippleQbandmode2. 10 min scan.
  • scan 22: RippleQbandmode3. 10s scan to change modes
  • calibrating ADCs.
  • scan 23: RippleQbandmode3. 10min scan.
  • No ripples!

Topic revision: r3 - 2015-01-27, RichardPrestage
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