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.