lbw rfi from cross head

    Progect a2335 (GASS) reported wideband rfi while using lband wide and the interrim correlator (with 1 second dumps) on 04may05. While investigating the problem, the rfi was seen to have a 1.2 Hz periodicty. This pointed to the cross head which has a 1.2 hz period.

    Data was taken with lbw and the mock spectrometers on 05may09 to investigate the problem with higher time resolution and bandwidth. The setup was:

.1 second time resolution:

    Data was recorded for about an hour. One of the worst 60 second spans of data was then selected to show how the interference appeared across the lbw band of 1100 to 1750 Mhz.

    Dynamic spectra

Total power vs time and periodicty of rfi (.ps) (.pdf):

.001 second time resolution.

    1 millisecond by 4096 channel, 172 Mhz data was also take for about 60 seconds. The rfi was not as strong during this data set.

    Dynamic spectra of 1115-1285 Mhz Band

    Total power vs time and periodicty of rfi (.ps) (.pdf):


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