{HEAD ~ The amplitude} of the output of receiver 24 is sampled by {TAIL ~ sample/hold circuit} 171 
is sampled by
{ HEAD ~ The amplitude } of the output of receiver 24 is sampled by { TAIL ~ sample / hold circuit } 171
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH