Again, in response to {HEAD ~ positive going pulses} in {TAIL ~ such train} of pulses, transistor Q2 is driven from a non conducting condition to a conducting condition, as shown in FIG 4B 
in
Again , in response to { HEAD ~ positive going pulses } in { TAIL ~ such train } of pulses , transistor Q2 is driven from a non conducting condition to a conducting condition , as shown in FIG 4B
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH