Re: FDC meeting minutes

[Gerard Visser <gvisser@indiana.edu>]

Hi Dan,
	This sounds good. It is important that we get going on ordering some 
cable as soon as practical (but of course only when we are quite sure 
it's the type to use). I would really like to have at least 100' here 
for electrical tests as soon as practical (by August or so would be 
excellent).
	About the jacket, thinner jacket sounds like a great idea. However, be 
careful that the cable retains the proper fire ratings (CL2/CMG 
probably). Most likely it must be so marked on the jacket, as well as 
merely passing the test. I would not be surprised if a change in the 
jacket required another NRE charge to perfrom the fire tests, etc. 
Amphenol guys will be able to say, anyway, whether a change in the 
jacket is more trouble than it is worth... I have no _real_ idea whether 
that is true, just a suspicion there is something to watch out for here.
	We're getting the PVC cable, right? Not the halogen-free stuff?

	Gerard

p.s. Fernando - please note carefully, according to the plan below the 
cable will be trimmed to 34 conductors for anode preamp usage. This is 
fine, but in this case I _strongly_ suggest that the pulser is carried 
on the first pair (marked pair) of the cable, and then the 24 (or 16) 
signal pairs come next. In this way, the anode boards _can_ be plugged 
into the ADC's with complete pin compatibility (for diagnostic or 
whatever purposes, we'll see), while at the same time of course 
retaining the marked pair as one of the 17 pairs on the trimmed-down cable.


----you wrote----
- As Joe was at today's meeting, we took the opportunity to talk about
    the cabling of the FDCs.  The current plan is to use the 50-conductor
    cables for both anodes and cathodes.  Note, as the anodes only have
    34-pin readout, 16 conductors in the 50-conductor cable will not be
    used (but they will be configured with 34-pin connectors).  This was
    decided as the nominal choice as the 50-conductor cables actually have
    less copper in them than the 34-conductor cables.
  - As the cables will surround the entire detector, Joe will work to
    produce a drawing showing the cable packing.
  - Joe will contact the manufacturer about making cables with a thinner
    outer jacket to reduce material thickness.
  - As the signal cables can have jackets of any color we choose, Joe
    suggested we use different color cables for each FDC package to allow
    for easier identification in the cable trays and electronics.  This
    was viewed as a good idea.
  - Joe asked that we consider purchasing cables for him to study.  The
    minimum order is $10k.

Daniel S. Carman wrote:
> 
> Folks,
>  
> The minutes from today's FDC meeting have been posted on the GlueX
> wiki at:
> 
> http://www.jlab.org/Hall-D/software/wiki/index.php/FDC_Meetings
> 
> Let me know if you have any comments or questions.
>  
>  
>  				Regards,
>  
>  					Daniel
>  
>  
> **********************************************************************
> *                                                                    *
> * Dr. Daniel S. Carman                   e-mail : carman@jlab.org    *  
> * Staff Scientist                        office : (757)-269-5586     *
> * Jefferson Laboratory                   web: www.jlab.org/~carman   *  
> *                                                                    *
> **********************************************************************
>