20apr11: rfi on telescope using 327 rcvr. (top)

• accurange3000 at distomat 1 position (about azimuth 35) along rim road. Shooting up to reflector on corner 12.
• mock spectrometer, 1 second dumps to record spectra. 172 MHz
  
• 327 rcvr. sitting
• lbw rcvr: 4 bands covering 1120 to 1750.

327 test:

• 327 laser actions

  sec	Action
  0	All off
  146	PowerSupply, laser on
  246	All Off
  458	PowerSupply, laser on
  524	All Off

• 327 dynamic spectra

  327 polA (.gif)

  327 polB (.gif)

  
  

lbw test:

• lbw laser actions

  Sec	Action
  0	All off
  75	PowerSupply,laser on
  150	All off
  208	PowerSupply on
  248	PowerSupply,laser on
  299	PowerSupply on
  342	All off

  
  

• lbw dynamic spectra

  CfrMhz polA	CfrMhz polA
  1200	1200
  1350	1350
  1500	1500
  1650	1650

Summary

• There are no obvious rfi  that follow the on,off pattern used for the distomat
• The images have used a decimate by 6 to display the 8192 channels.

06apr11: rfi from accurange3000 distomat in screen room.

•  Accurange 3000 sitting out in the screen room (no huffman box).
• agilent E4445A spectrum analyzer, 601 channels, and preamp on.
• 1 MHz to 10 Ghz. I've included the data from DC to 6 gHz.
  
• ETS model 7405 probles:
• 902:magnetic field. resonant freq 1.5 Ghz
• 903:magnetic field. resonant freq 2.3 Ghz
• 904:electric field: resonant freq > 1Ghz
• Move the probes around the device looking for maximum value (spectrum analzyer set to max hold).

• Page 1: 902 probe, 0 to 1.5 Ghz.
• top, middle, bottom are 500 MHz sections of 0 to 1.5 Ghz.
• Each color is a separate measurment with the spectrum analyzer.
• some of the spectra have a lower noise baseline. These have narrower resolution bandwidths.
  
• The dotted vertical lines are a comb ath 36.8789 MHz
• The strongest comb birdies are at:
• 295.031 MHz : -66dbm. This repeats for different measurements.
• 1032.61 MHz : -71dbm, 1069.49 MHz : -74dbm
• Page 2: 902 probe 1.5 Ghz to 6 Ghz
• top,middle, bottom are 1.5 Ghz sections from 1.5 to 6 Ghz.
• There are no obvious birdies that stick out  (but these resolution bandwidths are pretty wide.
• Page 3: compare the response of the 3 probes:
• the colors correspond to the different probes:
• black probe 902 (res freq 1.5 Ghz).
• red     probe 903 (res freq 2.3 Ghz)
• green Electric field > 1Ghz.
• probe 902 and then 903 do the best job showing the comb. 904 does not see things above 300MHz.
• this test does not guarantee that the positions of the 3 combs were exactly the same.

Summary:

• The accurange3000 has a comb with a spacing of 36.8789 MHz
• we saw the comb with the probes up to about 1100 MHz.
  
• The strongest comb elements are:
• 295.031,1032.61,1069.49 MHz.
• probe 902 does the best job showing the probe up to 1.5 Ghz.