Re: Preamp tests

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

Hall D Electronics:

Hi Gerard,

I asked McCracken how we came to this design: the plan of CMU was to use 
coax cable to bring the signal from the sense wire to the HV board, the 
plan was to connect the cable shield to the HV board ground. There was a 
electronics meeting in Indiana where Paul Smith suggested to connect the 
cable shielding to the HV and not to the ground. Gerard opposed the idea 
of using coax cable. The decision on which capacitors to use came after a 
small calculation done at CMU.

I decided not to connect the cable shielding to ground when bringing the 
HV board outside the CDC end plenum because we saw no difference (using 
the old preAMP) with/without connection.

Plan:
 	step 1: I just started (together with Mike) to collect the 
material to connect the cable shielding to the HV line on the HV board. 
After that we will test this.

 	step 2: Change the capacitors on the board with the ones Gerard 
proposes and test -> Gerard, what type/value do you propose; i remember 
you saying we should also using a different type.

 	-- My hope is that this can be done in a short period of time and 
that we can take data afterwards --

 	step 3: first iteration in redisigning the board (shrink it, new 
orientation preAMp, maybe two ground planes, ...)


Cheers,
 	Yves