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<font face="Helvetica, Arial, sans-serif">Hi All,<br>
<br>
I did a first test of looking at the signals of the FMWPC. To be
more precise chamber 2 (second most upstream chamber)<br>
looking at signals from the lowest connector and second lowest
connector (in y)<br>
attached are a few scope plots that show the behavior of the
chamber in different conditions:<br>
tek00000.png: signal cable connected NO LV applied<br>
tek00001.png: signal cable connected +/- 5V on the chamber <br>
tek00005.png: same but with different timing scale (horiz. axis)
looking at lower frequencies<br>
<br>
there is significant noise coming in burst like we have seen in
the EEL.<br>
<br>
there is an easy way to reduce that noise significantly by making
an electric connection between<br>
the connector on the chamber and the aluminum shield housing.<br>
this can be seen in <br>
tek00008.png: see change in the vertical axis of the trigger.<br>
<br>
As stated earlier providing a good electrical contact between the
connector on the chamber and the shield<br>
housing will reduce the noise significantly. I talked to Mark
Stevens and Chris Blackburn to use the threaded<br>
bolt holes on the ends of the connector to make a "electric
bridge" between the connectors and the shield<br>
housing. As additional side effect this will also fix the PCB
board more rigid in place and avoid unnecessary<br>
bending to the sides when connecting the cables.<br>
<br>
<br>
cheers,<br>
Beni<br>
<br>
<br>
<br>
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