The pulse train fed to {HEAD ~ the base} of {TAIL ~ transistor Q1} has a period P and a duty cycle less than 50 percent 
The pulse train fed to { HEAD ~ the base } of { TAIL ~ transistor Q1 } has a period P and a duty cycle less than 50 percent
OTH OTH OTH OTH OTH 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