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7181More EME from Arecibo

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  • Joe Taylor
    Apr 23, 2010
    • 0 Attachment
      For a good laugh, you might want to see what we were confronted with
      when we switched to JT65B on the final day of KP4AO EME operations:

      http://www.physics.princeton.edu/pulsar/K1JT/KP4AO_JT65B_1.png

      JT65 is supposed to be a weak-signal mode, and by WSJT standards most of
      these signals are anything but weak! We did our best to pick out and
      reply to some of the weaker ones, during the all-too-short time we
      allocated to JT65.

      I have not yet had time to go carefully through our JT65B recordings to
      decode all signals. To give you an idea of what's possible, here's what
      I decoded a few minutes ago, from a single one of the one-minute wave files:

      UTC Sync dB DT DF W Message KV?
      -------------------------------------------------------------------
      203300 0 -10 1.9 -640 4 # KP4AO G6HKS IO92 OOO 1 0
      203300 5 -11 2.4 -231 13 * KP4AO PA3DOL JO22 1 0
      203300 4 -12 1.8 -221 4 * KP4AO HA0HO KN07 1 0
      203300 1 -22 1.5 -3 18 * KP4AO SQ7DQX JO91 1 0
      203300 2 -16 2.0 366 7 * KP4AO SP1JPQ JO73 1 0

      203300 0 -18 1.8 471 9 * KP4AO W6OUU DN22 1 0
      203300 2 -4 1.6 822 4 * KP4AO AF6O DM14 1 0
      203300 4 -12 1.7 1690 3 * KP4AO DF6SM JN58 1 0
      203300 2 -14 1.8 1879 10 * KP4AO YL3HA KO26 1 0
      203300 0 -14 1.7 2030 3 * KP4AO NA6MF CM87 1 0

      203300 1 -17 4.3 2369 3 * KP4AO KR7O DM07 1 0
      203300 5 -10 1.7 2412 3 * KP4AO DJ8MS JO63 1 0
      203300 4 -8 1.7 2879 3 * KP4AO DH1WM JN49 1 0
      203300 3 -7 0.7 2935 3 * KP4AO LU1C GF05 1 0
      203300 2 -17 1.8 3261 1 * KP4AO W8PAT EN81 1 0

      203300 0 -13 2.0 3312 9 * KP4AO EB3DYS JN11 1 0
      203300 6 -15 2.2 3522 3 # KP4AO SK4AO JP70 OOO 1 0

      Note that with all this QRM, numbers listed for "Sync" and "dB" may not
      be reliable.


      I've received many requests for the wideband recordings from KP4AO, so a
      selection of them have now been posted on the WSJT web site at the
      following URLs:

      http://www.physics.princeton.edu/pulsar/K1JT/EME_1.wav 4/16 startup
      http://www.physics.princeton.edu/pulsar/K1JT/EME_2.wav 4/16 CW
      http://www.physics.princeton.edu/pulsar/K1JT/EME_3.wav 4/16 CW
      http://www.physics.princeton.edu/pulsar/K1JT/EME_4.wav 4/17 SSB
      http://www.physics.princeton.edu/pulsar/K1JT/EME_5.wav 4/17 SSB
      http://www.physics.princeton.edu/pulsar/K1JT/EME_6.wav 4/17 SSB
      http://www.physics.princeton.edu/pulsar/K1JT/EME_7.wav 4/17 CW
      http://www.physics.princeton.edu/pulsar/K1JT/EME_8.wav 4/17 CW

      Files number 2-7 are all about 1 GB in size. File 1 is about 0.7 GB and
      file 8 only 41 MB. You may want to start with the shortest file,
      EME_8.wav, to get a feeling for what they all contain.

      With SpectraVue you should check "Invert Spectrum" on the "Wave File
      Input Setup" screen, and enter 432040000 in the "File Center Frequency"
      box. SpectraVue gives you date and time markers on the waterfall, so
      you can tell where you are (however, I've noticed that on 4/17 the times
      are certainly not correct). The data is blanked during KP4AO
      transmissions. The extremely strong KP4AO echo immediately follows each
      blanked interval.

      I prefer listening to these files with Linrad. This superb program is
      well worth the time required to learn how to use it effectively. If you
      already have some familiarity with the program, here's what you need to
      do to listen to the KP4AO files:

      1. Create a file "adwav" with a line naming each of the EME_?.wav files
      2. Start Linrad, select the desired file, enter "A" for weak-signal CW
      3. Answer "Y" to "Interpret as I/Q data?"
      4. Answer "Y" to "Invert frequency scale?"
      5. Enter "432.040" in the frequency control box

      Beyond these few hints to get you started, you're on your own with both
      SpectraVue and Linrad. I will appreciate it if you send me a list of
      all callsigns you hear in these recordings.

      With best wishes from the KP4AO gang,

      -- 73, Joe, K1JT
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