The voltage controlled oscillator oscillates at a frequency equal to the center frequency of the carrier of the input angle modulated wave, when {TAIL ~ the phase} locked {HEAD ~ loop} becomes unlocked 
The voltage controlled oscillator oscillates at a frequency equal to the center frequency of the carrier of the input angle modulated wave , when { TAIL ~ the phase } locked { HEAD ~ loop } becomes unlocked
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD OTH OTH