Monday, July 14, Notes

RABBIT Power Supplies
Gary reported that single ended testing appears to be a good technique.
Previously, there was no difference in the pedestal width between shielded and
unshielded supplies.  Now the RMS increased from 50 to about 200 counts when the
unshielded supply was used,  Changing to a shielded supply gave a factor of 2
decrease.  Other features were that there was a clear difference between the two
signal input cables, and the chamber was not configured for the optimum ground.

Digital Links Working Group
Gary has agreed to take over from Charlie.  A push to get all detector groups
stuff tested this summer is planned.  Testing will be done at wedge 21 using the
strip chamber pedestal width for a single-ended readout with a 300 nsec gate as
the diagnostic.

Power Supply Testing
There is a milestone approaching on July 30 when the consultant (Van Doren) is
giving a grounding and shielding course here.  He has agreed with Stan to look
at our situation and observe the test of a candidate supply with "new eyes".
The IEC has issued a standard calling for correction of the power factor to more
than 0.99 by August 1.  Stan's inquiries indicate that the major vendors are not
going to be able to meet this deadline.  We may not be testing the final thing
in this time frame.
CDF has size and space restrictions whereas one of these IEC-1000 compliant
units with power factor correction and communications capability is a 19 inch
relay rack package 2U high.  The commonplace "shoe box" size packages could be
mounted on the outside of a rack but require noise and communications
improvements plus another cycle of testing at the wedge.

Items
Information from CAEN about optocouplers for the control link should be sent to
Lindgren and Apollinari. (Elias)
Yale requests information on termination provisions needed at the crosspoints
where the cables come in.  (DeMaat)
Documentation topic is resurrected by Gary.
Cooling - there isn't a integrated effort of electronics cooling.  Alvin and
Aesook ask that this group consider organizing a one day workshop along the
lines of our grounding workshop.  All groups would explain just how they plan to
cool their stuff.  To be discussed further at the August meeting.

Next meeting - August 14, Thursday, 9:30 - unless this causes problems.