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    User name V. Sulkosky

    Log entry time 20:47:10 on October 20, 2008

    Entry number 244183

    Followups:

    keyword=EDTM Signal Connected to S2m

    I have measured the time difference between the S1 and S2m EDTM signals.

    For S1, the EDTM signal is inserted right before the LeCroy 4413 discriminator
    . For S2m, the signal is inserted via the S2m EDTM
    Amp module. Then the signal is sent to the S2m discriminators via 37 foot
    cables (57 ns) to the splitter boxes on the S2m detector frame.
    The signal then comes back through the S2m discriminator via 37 (50) foot
    cables for the left (right) side of the detector to the S2m logic units.

    The S1 EDTM module has an internal delay of 226 ns. The measured time
    difference between a signal through the S1 EDTM and the signal through
    the S2m cables to the logic units was measured to be 102 ns and 72 ns
    for the left and right S2m trigger cables. The S2m
    EDTM signal arrives before the S1 signal.
    For the coincidence time set up, we want the S1 and S2m EDTM signals to
    overlap as with the formation of the left HRS T3 trigger. To this end, I sent
    the EDTM signal for S2m through a LeCroy 4518 delay module with an
    added delay of 128 ns. With this added delay, the S2m EDTM signal comes
    about 46 ns and 78 ns for the left and right S2m cables after the S1 EDTM signal. This might be a bit too long, and if needed I can remove some of the extra delay.

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