Minutes - Interface Module Meeting 5/6/99
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Att: Foglesong, Johnson, Lipton, Matulik, with Sidwell, Sobering, and
Stanton via telephone.

1) Space, cable routing, etc- Foglesong- discussion of length of 3M cable
   Requested J1 and front panel new drawings.

2) Cables: NRS
Proposal from Noel to reduce # of ground lines in 80-conductor 3M cable
from 13 to 3. This allows for 6 DVDD, 6 AVDD, and 4 AVDD2 instead of the
present 2 lines per SVX voltage. Total impedance drops from 1.1 ohms
(per 20') to <0.4 for the voltages with highest current. This plan
REQUIRES a good connection to ground to the shield- a sore point. 3M is
moving to Fujipoly, and Marvin and others are skeptical of this.
Additionally, the layout of the mini-coax needs to be specified, we need
to be able to remove cards. It was agreed that Noel's proposal will be
the base line design.

3) Tests of low mass cables: Marvin proposed we plan to run  ~8 low
mass cables, presumably those from Speedy. We will have to use 50-conductor
cables from the interface module, so the setup would be:
   a) KSU interface module
   b) adapter to map from Belden cable to 50-conductor 3M (boards exist, need
   to stuff)
   c) 20-25' 50-conductor 3M cable
   d) adapter from 3M to Speedy flex cable (boards exist, need stuffing)
   e) Speedy serpentine cable (8')
   f) adapter from Speedy cable to HDI (boards exist)

KSU will supply items a), b), d), e), and f) for 8 channels.

Johnny Green will contact 3M regarding 5 80-conductor 3M cables for future
tests.

4) Split bias voltage proposal- Lipton
   Ron made the case for leaving in the option to supply split biasing to the
double-sided detectors (502 connections). It is not expected to be an issue
until
some time into the run, when radiation damage gets serious. We punted on the
HV supply issue (don't have enough) for now. RAS stated that EDL will layout
J1 with 34-conductor twist&flat, and see if space is available for the items
needed there (16 HV lines, SVX power, interface module power, differential
1553 signal lines, and 10 bit geographic address lines).

Jobs for next week:
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1) partial drawings of enclosures and crates from new draftsman
2) Front panel layout
3) J1 layout
4) Rev 2 and other tests

We have yet to address monitoring and 1553 functioning.


--
Ron Sidwell, 116 Cardwell Hall
Physics Dept, Kansas State University
Manhattan, KS 66506

tel (785)532-1639
fax         -6787

sidwell@phys.ksu.edu