327 Mhz rfi in p1693 data

Intro:

P1693 is the 327 Mhz pulsar search project. It is run by julia
Their setup is:

327 receiver in drift mode, 750Narrow band if (60 Mhz filter)
mock spectrometer: 1024 channels, polAdding, 125 Usec sampling, 57 Mhz bandwidth centered at 327 Mhz
drift scans of 1 hour duration (repeated multiple times).
A strip is one 24 hour cycle at a given position. Strips normally take more than one observing session to complete.

Data was taken during the T8-m4 cable repair.. (every night for many weeks).
Processing the data:

Dynamic spectra were made using the first file (129 seconds) of each 1 hour scan.
for each 129 secs scan

The median bandpass is computed
a harmonic fit of order 46 is made and used to normalize the bandpass for each 1 second spectra.

The table below has the different dynamic spectra:

04mar14: at 16:07 meteor camera atop antenna test range turned off. In dynamic spectra occurs at:16:75

seen in 18feb->20feb
it is seen to drift by up to 4 Mhz
there is another birdie that drifts in the opposite direction starting at 333 and coming down.

for more info see (27feb14: 320-325 Mhz drifting birdie seen feb14)
RESOLUTION: 20mar14: this was coming from the sbn postamp chassis. It was brought down to the lab 20mar14 16:00 to be checked.

I tried turning off the single pixel dewar monitoring on ,off 24feb14 afternoon to see if the rfi changed:

time	change	notes
16:54:00	all monitoring off	1.5sec birdie stopped
16:59:01	all back on	1.5 sec birdie restarted
17:04:30	all off	birdiie goes away
17:05:00	all on , except no monitoring of 327	1.5 sec birdie present
17:08:02	all off. left off for the evening

no obvious birdie changes while cycling the monitoring system
the drifting birdie was close to 319.5 at 15:00 . (see dynamic spectra for 140224 above). This did not change with the dewar monitoring changes.

processing:usr/p1693/doprocdays.pro

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