1384 MHz birdie mar09

plots:

    Project a2010 (alfalfa: alfa with 100 MHz centered at 1385, wapps, and 1 second dumps) reported birdies at 1384 and 1385 MHz during their observations on 13mar09,14mar09. A2133 (auds) integrations with the pdev spectrometer also showed these birdies as well as the x111 taken on 13mar09 with the interim correlator.

x111 60 seconds integration on 13mar09 (.ps) (.pdf):

• This data was taken with the interim correlator using lbw and 25 Khz resolution.
  
• Top: 60 seconds integration showing birdie at 1384.389
• Bottom: 60 second integration showing birdie at 1424.397

• The routine did 20 230 second drifts. Each drift starts at the same ra.
• the pdev spectrometer was used with 20 Khz resolution.
  
• The entire nites data was averaged for each beam (20*230 second integrations).
• beams 0 thru 5 are plotted with offsets. Beam 0 on the bottom, beam 5 on the top.
• Each page is a different 10 MHz range of the data. PolA on the top, polB no the bottom.
  
• page 1: 1380-1390 MHz.
• flag rfi at 1384.32,1386.89,1388.14,1389.83
• Page 2: 1410-1420
• Flag rfi at 1413.75, 1417.81, 1419.08
• Page 3: 1420 - 1430
• flag rfi at: 1422.03, 1422.36, 1424.33, 1425.01, 1425.94

• The average value at 1384.32 is plotted for each of the 20 230 seconds.
• The solid line is pola, the dashed line is polB
• Each beam is plotted in a different color with an offset.
• The vertical scale is Tsys.
• The strongest value was beam 0 polA (black solid line) in drift number 10 where it was 20% of Tsys.

Summary:

• The 1384, 1424 birdie was seen with the wapps, pdev, and interim correlator so it is not an intermod in the backend.
• The 1384,1424 was also seen using alfa at 250Mhz and lbw using the 750 Mhz IF so it is probably not an intermod in the first mixer.