60 Hz in the 327 receiver.

Sections:
p1693 pulsar data taken jan07 to 05may07 with wapps
baseband sampled data with ri 03/04may07
conclusions

Plots/images:
P1693 plots of the total power spectra (.ps) (.pdf )
P1693 total power  dynamic spectra using all 953 files (.gif)
P1693 high resolution total power dynamic spectra covering 0 to 150 Hz (.gif)
03may07 RI  baseband sampled data (.ps) (.pdf):
03may07: dynamic spectra with .5 Hz resolution
04may07: baseband sampled data on sky and load (.ps) (.pdf)
05may07:baseband sampled data with 100 hz offset tone (.ps) (.pdf)


Intro:

    A strong 60 hz component was seen in p1693 pulsar data taken with the 327 receiver and the wapps around 01may07. It had not been present in data taken a few months earlier. It went away (the strong version of 60hz) by the evening of 03may07. To check out this problem the p1693 from jan07 thru 05may07 was inspected. Baseband data was also taken on 03,04,05 may07 using the radar interface (ri).


The p1693 pulsar data

    P1693 is doing a pulsar search with the 327 receiver using the wapps. The experimental setup is:

Processing the p1693 data jan07 thru 05may07:  (top)

    An average spectra of the total power points was computed for each file. The processing was:
  1. For each 256 usec acf  compute the total power from the 0 lag.
  2. Compute a 64K spectra of these total power points:
  3. Average the 16 spectra of each file.
  4. When done there were 953  64k long spectra  covering jan07 to 05may07.

Plotting the total power spectra:  (top)

    The plots of the p1693 total power spectra (.ps) (.pdf ) show:

Dynamic spectrum of the tp:  (top)

    The first image is the total power  dynamic spectra for all 953 files (.gif).
    The 2nd image is the high resolution total power dynamic spectra covering 0 to 150 Hz (.gif): The resolution is 1/16 Hz.

Baseband sampled data with the ri.

    Baseband sampled data was taken on 03may07 and 04may07 using the ri (12 bit a/d's) the setups were:
date
rfCfr
MHz
Bw
MHz
Pols
Time
secs
Notes
03may07
327
1.
A
120
On sky.
04may07
310
.01
A,B
300
sky and load
05may07
312
.01
A,B
16
sky with 100 Hz offset tone.

Processing the data:

    The data processing steps were:

Plotting the data:

    03may07 data:
     The first plot shows 60 Hz in the 03may07 baseband sampled data (.ps) (.pdf): This was 1 MHz baseband data  centered at an rf frequency of 327 MHz. Only polA was sampled.
    A dynamic spectra with .5 Hz resolution was made from the same data set.
    04may07 data
    The 2nd plot shows 60 Hz in the 04may07 baseband sampled data (.ps) (.pdf): The data was 10 Khz of baseband data centered at an rf frequency of 310 MHz. Both polA and polb were sampled.
   05may07
    The 2rd plot shows 60 Hz in the 05may07 baseband sampled data (.ps) (.pdf): The data was 10 Khz of baseband data centered at an rf frequency of 312 MHz. Both polA and polb were sampled. A tone at 312MHz + 100 Hz was added for a frequency reference.
  

 The image shows they dynamic



Conclusions:  (top)

processing: x101/070503/wappcmptp.pro, wappproctp.pro,327ri.pro, 070504/327ri.pro
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