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    User name Ramesh/Diancheng

    Log entry time 21:59:42 on November 11, 2009

    Entry number 299029

    keyword=Phillips 740 replaced by LeCroy 428F in RHRS pvdis setup

    Diancheng and I took an access to replace the PS740 fan in/out modules by
    LeCroy 428F modules due to the unstable offset drifting in PS740 by about
    +-10 to +-20 mV level. We have replaced 4 Phillips 740 modules in the
    back rack of the right HRS pvdis setup. Before we removed the PS740, we
    have measured their offsets. To our surprise, they were not that large
    this time; these values are given below. After replacing them by LeCroy
    428F, we have set the offsets of these LeCroy modules to zero too.

    Starting from left (while facing towards the relay-rack):

    Module quad offset (mV)

    1st all 4 quads 0

    2nd top 0

    2nd top 2nd -6

    2nd top 3rd -10

    2nd bottom -6

    3rd top -5

    3rd top 2nd -8

    3rd top 3rd -12

    3rd bottom -8

    4th top -3

    4th top 2nd -5

    4th top 3rd -7

    4th bottom -8