Wide band look at AC birdies in 327 rcvr.

Dynamic spectra while the old AC unit was turned off and then back on (.gif) :
Average spectra of ACon - ACoff  across 25 Mhz (.ps) (.pdf).

    On 20oct05 the old AC unit in the dome was powered on off while data was taken with the interrim correlator. The datataking setup was 25 Mhz over 2048 channels and hanning smoothing. This gave a channel width of 25 Khz. Previous measurements showed that the birdie was not resolved in a 95 hz channel so the 25Khz channel width is not a very good match.  Data was dumped once a second for 300 seconds. The telescope was sitting still.
    The data analysis consisted of:

    The dynamic spectra image (pol A) shows where the Old AC unit was turned off and then back on (.gif) :

    Average spectra were also made for the AC on and AC off records. The difference of these averages shows the AC comb across 20 Mhz (.ps) (.pdf). The data shows that the AC unit extends across the entire band. The strength varies between polA and polB. The 2nd Ac unit is creating a similar comb (although offset in frequency).

More info can be found at (AC units in the dome create rfi).

processing: x101/Y05/051020/327.pro