Last night, Vince, Brad and I were checking the T3 double pulses issue, and found that certain S1 channels have after pulses. We increased the threshold of S1 DIS and at that time we saw the second pulse went away. Unfortunately today when I checked it again, this pulse still exists when the EDTM is on. I can try to increase the threhold again to see how it goes but I am a little worry about keeping this high threshold values during experiments.