Beam2a jumps 28nov11
28nov11
a2048 (ages) reported jumps in beam 2a of alfa on 28nov11.
The plots show the jumps in beam2a
(.ps) (.pdf):
- file: wapp.20111128.a2048.0002.fits was used. ( I excluded the 2
cal spectra at the start).
- Page 1: total power vs time . Black in beam2A, red is beam 2B.
- Top: total power vs time. The vertical scale in linear in power
- You can see the jumps at: 69,114,693, and 731 seconds.
- Bottom: blowup samples
680 - 750 seconds.
- The power has been normalized to the median value.
- At 711 seconds it gets down to about 30% of Tsys.
- The values at 710 and 712 are equal. A bit of a
coincidence if this was an analog variation.
- Page 2: Spectra for time samples 700 - 714 seconds.
- Top: spectra 700-714 over plotted.
- Middle: spectra 700 and 711 over plotted.
- Bottom: Ratio spectra[700]/spectra[711]
- The HI line at 1420 MHz has canceled out so tsys must not
have changed appreciably for the 2 spectra.
Summary:
- Beam 2a showed jumps that for many seconds.
- The system temperature did not change during the largest dropout.
- Looks like it might be a problem with the wapps (maybe the
attenuators?)
processing:
x101/111128/agesjump.pro
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