{HEAD ~ A train} of positive going pulses is fed to the base electrode of transistor Q1 by {TAIL ~ controller} 14 via line 15 
{ HEAD ~ A train } of positive going pulses is fed to the base electrode of transistor Q1 by { TAIL ~ controller } 14 via line 15
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH