Cable + shaper board

[Yves Van Haarlem <yvhaarle@ernest.phys.cmu.edu>]

Hall D Electronics:

Hi Gerard, Fernando,

Today the 18m long cable arrived! Thanks.

After installing it a problem showed up with the shaper board. It was the 
same problem that showed up before: some channels have a 10x lower gain 
than the others (ch 1-2-3, starting from zero). It is a bit worrisome that 
before the problem showed up in only one channel and after a while it 
recovered but now 3 channels show it. More info and some scope traces can 
be found in:

 	http://www.jlab.org/Hall-D/software/wiki/index.php/CDC_20_02_2008

To me it looks like the problem is somewhere near the 3M connector because 
when you inject signals using the other connector the problem does NOT 
show up. I used two different cables (the new one and the one Gerard made) 
and the problem persists.

For the moment we just take cosmics anyway + one read out channel is now 
used to read out the cosmic trigger using the NIM signal attenuator from 
Gerard.

Would it be reasonable to ship another shaper board to CMU soon?

Cheers,
 	Yves


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