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    User name yez

    Log entry time 11:59:08 on February 24, 2011

    Entry number 348435


    keyword=LHRS: move two cables of PRLs to other ADC channels

    We have two cables which include several PRLs PTMs that give only
    pedestals but not real signals. I tested both cables and it looks like
    the cables themselves are good, and I also double checked the PMTs'
    signals from Patch Panel downstairs and they are visible in the scope
    which means that the PMTs are also OK. I decided to move the cable of
    17L~32L from Slot24:16~31 to Slot25:16~31, and move the cable of 33,34L/R
    from Slot25:16~31 to Slot25:32~47. The 33,34L/R was in 0~15 and David
    moved it to 16~31, but the data taken after the change shows nothing
    different as before so I decide to move it again, while put 17L~32L in
    this group(25:16~31) to verify whether this group itself is bad or not. 
    I have a question is: 
    Is 1881ADC receiving positive ADC signals? Why I ask is because that I
    found the 50ohm filters that connect from the ribbon cables and put into
    the ADC module flip the signals from negative to positive. 

    A copy of this log entry has been emailed to: kalyan@jlab.org,vasulk@jlab.org,danez@jlab.org