[Halld-electronics] first result of GPC-II / actual cable assy / ADC125

[Gerard Visser]

Hi Fernando,
	Attached is a plot of 16 channels responding (and 8 not) to an (external) 
positive step test pulse on a wire crossing the input traces on the old 
'interposer' board. I realized only after seeing this that only 16 channels are 
connected on the interposer board, no doubt. So I'll have to modify my setup to 
externally pulse all 24. Meanwhile will also attempt to get some calibration in 
place and set up the logarithmic input pulse to simulate actual chamber 
response. But I thought you might like to see this plot already, perhaps even 
include in your presentation tomorrow if it's not way too late.
	Sincerely,

		Gerard

p.s. For others' info, this GPC-II board is set up for FDC cathode signals, I 
believe. And this makes sense given the polarity of the output pulse here which 
is opposing the baseline offset from mid-scale on the ADC.
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