Thursday,  March 19  Notes

Present:  A. Byon, R. DeMaat, C. Drennan, J. Elias, S. Hahn, C. Nelson,
	  S. Orr, G. Pauletta, K. Schuh, S. Segler

PISA Boxes
     Two problems were discussed, ground loops and serial control link
interference.  For safety, the case of the box must be grounded through the
power cord.  Suggestions to lift other grounds were to fasten the HV connector
panel with nylon screws (its anodized) and float the case of the box from the
wedge steel.  This would leave the serial coax link as (1) still forming a
ground loop with the first floor through the power cord ground but not
necessarily through the detector steel, and (2) a source of interference when
active.
     The discussion ended with agreement that testing is needed.  The idea is to
start with conditions as per Run I and reproduce the noise problem, and then
make the changes one at a time measuring the impact.  Dealing with the serial
link problems will depend on the results obtained.  Ingredients of the testing
are CAMAC for serial link operations (Pauletta), wedge noise test runs (Hahn &
Drake), and EMI measurements (Drennan).

Plug Temperature System
     C. Drennan discussed the results of near-field EMI measurements on the plug
phototube box temperature monitoring system interconnects.  There was noise seen
from both the DALLAS temperature chip serial bus and the IEEE485 interface to
the PC.  However, the conducted noise from the PC was larger than that of either
bus.  The issue is not yet resolved with the Brandeis team working on a second
generation prototype.  Note that these noise problems must be resolved if the
DALLAS temperature transducers are to be used on the arches.