Re: Contact Information for Electronics

[Gerard Visser <gvisser@indiana.edu>]

Hi Fernando,
	Ah, ok, this makes sense, it is a good plan. I would intend to be 
leaving them (CDC) with a shaper board properly set up for the new 
preamp. So they should then be in a position to use real cable length.
	I'm cc'ing Joe and the list here, about the cable lengths... Is the 
following known yet:
	What lengths of cable are expected for the FDC in what quantities each?
	What lengths of cable are expected for the CDC in what quantities each?
	All that I know so far is that the _maximum_ FDC cable is 21m (69 
feet), and now also I learn same _maximum_ is anticipated on CDC (I'm 
surprised by that a little bit, given what I think I remember of the 
floorplan). It would be good to get to a table like this:

FDC cathode
-----------
N1 cables length 21 m
N2 cables length 19 m (or whatever)
N3 cables length 16 m (or whatever)

FDC anode
---------
similar

CDC
---
similar

	It is clear that equalization is needed to get the signals out of these 
cables... To design it we need to get a firm handle on the lengths. This 
_can_ be deferred - but I probably would prefer to sketch out some 
actual design. For this at least I'd like to know the range of lengths 
and how many different lengths. (Hopefully the range is small enough we 
don't really need different values of equalization.)

	Gerard
	

Fernando J. Barbosa wrote:
> Hi Gerard,
> 
>     The 10 ft cables are just for looking at signals out of the cards
> with a scope or for similar probing - just to get them started. The
> cable will be spliced at one end and have the ERNI connector on the
> other. Elke suggested a small length of cable as they don't have any
> shaping boards or your fADCs. I think it would be just useful for
> debugging any noise issues and getting familiar with the cards.
> 
>     I suggest you look at the signals with the long cables, perform the
> shaping and then tell them what they need. They really need a shaping
> board before they can perform any useful tests, I think. I can then send
> a long cable. Joe still believes 65 ft should be enough.
> 
> Regards,
> Fernando