In operation, the variable delay element 30 provides {TAIL ~ a variable delay} whose magnitude is directly related to the composite of the degrees of operation of the differential sections D1 and {HEAD ~ D2} 
In operation , the variable delay element 30 provides { TAIL ~ a variable delay } whose magnitude is directly related to the composite of the degrees of operation of the differential sections D1 and { HEAD ~ D2 }
OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL 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 HEAD HEAD HEAD HEAD HEAD