17 January 2014 Testing

Goals

  • see how the ripples change in X-band in mode 1 or 2 with different attenuation levels
    • running archivist to record measured power.
    • Richard's suggestion was to run different levels from -20 to -15 or so to see how things change.
    • we have all eight banks hooked up to see if it changes between banks.
  • Try test with both mode 1 and mode 2
  • want to do a long integration on X-band at best attenuation levels to see what's up.

Questions to Answer

  • Is there another balance level that minimizes that ripples?
    • Looks like -18 to -17 might be better for mode 2 and for some cases in mode 1.
  • Is one polarization consistently better than another?
    • In mode 1 LL has worse ripples than RR. Mode 2 LL and RR are similar
  • Do all the banks show the same behavior?
    • mostly
  • Do some of the features correspond to known RFI at X-band?
    • Looks like crud at ~9.3 GHz is known RFI.

Log

  • Session 29
  • running mode 1 with archivist and with VEGAS
  • F and H failed to balance
  • problem in converter rack modules
  • otherwise can control the balance
  • Note that X-band is not at the focus position right now
  • Testing mode 1
  • Scan 7-8 -- test scan target level -18
  • Scan 9-10 -- test scan target level -20
  • Scan 11-12 -- test scan target level -19
  • Scan 13-14 -- test scan target level -18
  • Scan 15-16 -- test scan target level -17
  • Scan 17-18 -- test scan target level -16
  • Scan 19-20 -- test scan target level -15
  • Pause for Mike Stennes to get Ku-band installed.
  • Testing Mode 2
  • Scan 21-22 -- test scan target level -20
  • Scan 23-24 -- test scan target level -19
  • Scan 25-26 -- test scan target level -18
  • Scan 27-28 -- test scan target level -17
  • Scan 29-30 -- test scan target level -16
  • Scan 31-32 -- test scan target level -15

Data Analysis

  • Plots and analysis scripts are in /users/akepley/scratch/vegas_tests/vegas_test_17Jan2014
    • test.analysis describes what I did.
    • compare_levels.pro is a helper routine to plot the different spectra
    • the directories mode 1 and mode 2 have plots comparing the spectra for different modes.
      • the colors are red=-20, white=-19,green=-18, orange=-17, purple=-16, cyan=-15, magenta=-14.
  • Mode 1
    • The ripples are always noticeably larger in PLNUM=0 (LL) than in PLNUM=1 (RR).
    • Banks F and H did not balance.
    • For Banks A through C, I'm finding good levels at ~ -18 (+/- 1).
    • For Banks D, E, and G, I'm finding good levels at -20
  • Mode 2
    • -20 dB has some serious ripples. The ripples are about the same amplitude in both polarizations.
    • balance at -17 or -18 seems about right.

-- AmandaKepley - 2014-01-17
Topic revision: r1 - 2014-01-17, AmandaKepley
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